A new method for the removal of environmental compounds from gaseous streams, in particular, flue gas streams. The new method involves first oxidizing some or all of the acid anhydrides contained in the gas stream such as sulfur dioxide (SO2) and nitric oxide (NO) and nitrous oxide (N2O) to sulfur trioxide (SO3) and nitrogen dioxide (NO2). The gas stream is subsequently treated with aqua ammonia or ammonium hydroxide which captures the compounds via chemical absorption through acid-base or neutralization reactions. The products of the reactions can be collected as slurries, dewatered, and dried for use as fertilizers, or once the slurries have been dewatered, used directly as fertilizers. The ammonium hydroxide can be regenerated and recycled for use via thermal decomposition of ammonium bicarbonate, one of the products formed. There are alternative embodiments which entail stoichiometric scrubbing of nitrogen oxides and sulfur oxides with subsequent separate scrubbing of carbon dioxide.

1. Field of the Invention
This invention relates to a process for the treatment of industrial effluent gases, and, more specifically, this invention relates to a process for the removal of carbon dioxide (CO2), nitrogen oxides (NOx), and sulfur dioxide (SO2), as generated from sources such as power plants that utilize fossil fuel.
2. Background of the Invention
Uncontrolled acid anhydride gases in flue gas produced by the combustion of fossil fuels have long been a cause of acid-rain-related air pollution problems. The acid anhydride precursor gases which cause the most serious problems are sulfur dioxide (SO2) and nitrogen oxides (NOx). (Sulfur dioxide and NO are precursors to sulfur trioxide (SO3) and nitrogen dioxide (NO2)). Another acid anhydride precursor gas caused by fossil fuel combustion is carbon dioxide (CO2) which can cause global climate change or the "greenhouse effect." Carbon dioxide can exist in flue gases at concentrations hundred of times higher than the combined concentrations of SO2 and NOx.
Methods to prevent these acid anhydride gases from entering the atmosphere are technically complex and very costly, especially if each acid gas is to be removed by a different technology. For example, limestone slurry (calcium carbonate, CaCO3) scrubbing can be used for SO2 removal with subsequent selective catalytic reduction (SCR) for NOx reduction and a wet scrubbing amine process (e.g., monoethanolamine, MEA) for CO2 capture.
Amine-Based CO2 Absorption Technologies
Absorption processes using aqueous amine solutions have been used to remove CO2 from gas streams in some industries. These processes often are referred to as wet chemical scrubbing.
Wet chemical scrubbing of CO2 involves one or more reversible chemical reactions between CO2 and amine substances in aqueous solutions of monoethanolamine (MEA) or diethanolamine (DEA) to produce a liquid species, such as a carbamate. Upon heating, the carbamate breaks down to free CO2, with the original amine regenerated to react with additional CO2. An example of the process, with MEA, is given by Equation 1:
                                          2                                                                                RNH              2                                +                      CO            2                                            ↔          hot          cold                                              RNH            3                              COOHNR                                    Equation                                                  1            for which the two moieties represented by R may be either any alkyl moiety, any aryl moiety, or any combination thereof. At high CO2 concentrations, bicarbonate formation may also take place.
Typically, these amines, MEA and DEA, are used as 15 to 30 wt. % amine in aqueous solution. The amine solution enters the top of an absorption tower while the carbon dioxide containing gaseous stream is introduced at the bottom. During contact with the CO2-containing gaseous stream, the amine solution chemically absorbs the CO2 from the gaseous stream to create a carbamate. Conversion of carbamate ions back to CO2 proceeds through a thermal regeneration process, typically at a temperature of about 120° C. Carbon dioxide and water emerge from the amine solution and the water is separated via condensation using a heat exchanger. After regeneration, the amine solution is recycled back to the absorption tower for additional CO2 absorption.
Carbon dioxide capture and regeneration in the above-described manner require high temperatures or very low vacuum. Regeneration of CO2 from MEA solution may use up to 80% of the total energy consumed in the CO2 absorption and regeneration cycle. As such, the process outlined supra is energy intensive. Further, the amine solution has a limited lifetime due to degradation through oxidation of the amine. In addition, high amine concentrations and high CO2 loadings exacerbate corrosion problems of process equipment.
MEA systems require that SO2 be removed first from flue gas streams, otherwise, MEA is degraded by SO2 and oxygen (O2), forming irreversible products. Specifically, if the SO2 is not removed, amines combine with SO2 in flue gases from coal-burning power plants to produce insoluble salts. The insoluble salts cannot be regenerated by thermal decomposition. Thus, the insoluble salt must be disposed of at a considerable cost. Also, the amine solvents such as MEA must be replenished because part of it forms the waste-byproduct along with SO2.
NOx must also be eventually removed from the flue gas before it is discharged into the air in order to meet present and future gaseous emission limits. NOx nominally consists of approximately 95% NO (nitric oxide) and 5% NO2 (nitrogen dioxide). NOx removal occurs upstream of the CO2 absorber and is accomplished by low NOx burners and/or selective catalytic reduction.
Current Ammonia-Based SO2 Absorption Technologies
Commercial processes exist that contact environmental flue gases with gaseous ammonia to remove sulfur oxides. Ammonium bisulfite is formed with subsequent oxidation to ammonium bisulfate, and eventual neutralization of the bisulfate with water and ammonia to form ammonium sulfate.
Other processes contact combustion or flue gases containing sulfur oxides with solutions of ammonium sulfate/sulfite, and in one instance, the resulting solution is reacted with H2S to form ammonium thiosulfate. These aqueous-based processes do not remove nitrogen oxides, primarily because the more abundant nitric oxide has a limited solubility in water.
One commercial process uses ammonia to simultaneously remove SO2 and NOx within one reactor and produce mixed ammonium sulfate and nitrate fertilizer. This process is described in R. R. Lunt and J. D. Curic, Profiles in Flue Gas Desulfurization, 76-77, American Institute of Chemical Engineers (2000). Flue gas is first partially saturated and cooled with water to a temperature of 150°±10° F. The flue gas is subsequently mixed with ammonia and passed to the reactor where the flue gas-ammonia mixture is subjected to beams of high energy electrons to oxidize the sulfur dioxide and NOx. These oxidized species subsequently react with the ammonia to form ammonium sulfate and ammonium nitrate particulate. This process does not address the greenhouse gas (CO2) capture and removal problem. Further, the process gives an undesirable trace byproduct, ammonium sulfamate, which is harmful to crops. Finally, the process is expensive.
Studies demonstrate the efficacy of a wet ammonia scrubbing process for the removal of carbon dioxide from flue gases. A. C. Yeh and H. Bai, "Comparison of Ammonia and Monoethanolamine Solvents to reduce CO2 Greenhouse Gas Emissions," The Science of the Total Environment, 228, 121-133 (1999), and H. Bai and A. C. Yeh, "Removal of CO2 Greenhouse Gas by Ammonia Scrubbing," Ind. Eng. Chem. Res., 36(6), 2490-2493 (1997). The CO2 regeneration step in this process requires no more than 20% of the energy necessary for the CO2 regeneration step in MEA-based processes. Further, the regeneration temperature (60° C.) in this wet scrubbing process is half that required in MEA systems.
The Krupp Koppers process uses ammonia (NH3) solution in a wet scrubber to remove SO2 from flue gas. However, inasmuch as NO is not soluble in ammonia solution (NO must be oxidized to NO2 to become soluble in ammonia solution), NO is removed by a second process in a second reactor, which is called Selective Catalytic Reduction (SCR). The SCR process is energy-intensive because the flue gas must be reheated to 300° C. This process is described in W. Schulte, "Flue Gas Cleaning With Ammonia Reduces SO2 and NOx Emissions," Thirteenth International Pittsburgh Coal Conference Proceedings, Sep. 3-7, 1996, Pittsburgh, Pa.
The Marsulex process is similar to the Krupp Koppers process in that Marsulex focuses on SO2 removal using ammonia in a wet scrubber. However, the Marsulex process does not address CO2 and NOx capture and removal from flue gases. This process is described in M. A. Walsh, Jr., "New Marsulex Technology Significantly Cuts Power Generation Costs," Corporate Publication (2000).
Gas-phase oxidation of nitric oxide (NO) to water-soluble nitrogen dioxide (NO2) can be accomplished by strong oxidizing agents such as hydrogen peroxide (H2O2), ozone (O3), and chlorine dioxide (ClO2). Hydrogen peroxide-enhanced gas phase oxidation of nitric oxide has been demonstrated. J. M. Kasper, C. A. Clausen III, and D. C. Cooper, "Control of Nitrogen Oxide Emissions by Hydrogen Peroxide-Enhanced Gas-Phase Oxidation of Nitric Oxide," Air & Waste Manage. Assoc., 46(2) 127-133 (1996).
U.S. Pat. Nos. 6,416,722 and 6,355,084 awarded to Izutsu, et al. on Jul. 9, 2002 and Mar. 12, 2002, respectively, disclose a method for desulfurizing gases by contacting sulfur oxides with gaseous ammonia with subsequent electron beam irradiation.
U.S. Pat. No. 6,221,324 awarded to Coq, et al. on Apr. 24, 2001 discloses a method for the removal of nitrogen oxides from waste streams by selective catalytic reduction contacting the waste gaseous stream with ammonia over zeolite catalysts.
U.S. Pat. No. 6,197,268 awarded to Hwang, et al. on Mar. 6, 2001 discloses a method for the removal of nitrogen oxides from waste streams by contacting the waste gaseous stream with gaseous ammonia.
U.S. Pat. No. 5,648,053 awarded to Mimura, et al. on Jul. 15, 1997 discloses a method for the removal of both carbon dioxide and nitrogen oxides from combustion or flue gases by contacting the gaseous stream, after oxidation treatment, with an alcohol amine.
U.S. Pat. No. 5,512,097 awarded to Emmer on Apr. 30, 1996 discloses a method for the removal of sulfur oxides from waste streams by contacting the waste gaseous stream with an aqueous slurry of finely comminuted limestone.
U.S. Pat. No. 5,510,094 awarded to Bhat, et al. on Apr. 23, 1996 discloses a method for the removal of sulfur oxides from waste streams by contacting the waste gaseous stream with oxidants. Subsequent to oxidation, the gaseous stream is contacted with an aqueous slurry of limestone and gaseous ammonia in a scrubber tower.
U.S. Pat. No. 5,176,088 awarded to Amrhein, et al. on Jan. 5, 1993 discloses a device and method for the simultaneous removal of nitrogen oxides and sulfur oxides from furnace exhausts. Injections of limestone, then ammonia are made into the furnace with subsequent contacting of the furnace waste stream with ammonia and calcium sorbent in a dry scrubber for additional sulfur oxides removal.
U.S. Pat. No. 4,426,364 awarded to Cooper on Jan. 17, 1984 discloses a method for removing nitrogen oxides from gases, after oxidation treatment, by contacting the gases with a bicarbonate/carbonate aqueous solution.
U.S. Pat. No. 4,251,496 awarded to Longo, et al. on Feb. 17, 1981 discloses a method for removing sulfur oxides and nitrogen oxides by first contacting the gaseous mixture with cerium oxide to remove sulfur oxides, then contacting the gaseous mixture with gaseous ammonia to remove nitrogen oxides.
None of the aforementioned patents or papers disclose any efficacious method or process for the simultaneous removal of a plurality of gaseous acid anhydrides and acid halides from combustion or flue gases. In addition, the state of the art does not disclose an aqua ammonia scrubbing process for gaseous acid anhydrides and gaseous acid halides. None of the aforementioned patents, papers, and processes address the potential capture and removal of greenhouse gases (CO2), together with removal of SO2 and NOx.
A need exists in the art for a method and device to remove all environmental gases, including CO2, from flue gases without producing any harmful byproducts. The method should be an aqueous-based ammonia scrubbing method and device to facilitate the removal of gaseous acid anhydrides, including nitric oxide, and acid halides from combustion or flue gases. Finally, the method and device should have low energy usage to minimize costs.

Multi-component removal in flue gas by aqua ammonia

United States of America Department of Energy


A flexible ionizer uses soft X-ray and has a head unit generating soft X-ray whose wavelength is 1.2˜1.5 Å, a soft X-ray protect unit shielding the leak of the soft X-ray from the head unit, and a power control unit supplying a control signal and control voltage to the head unit. The head unit is positioned outside of the soft X-ray protect unit with the flexible ionizer further having a flexible tube protecting a high voltage cable that connects the head unit and power control unit from external impact or vibration and letting the user bend the head of the head unit at an arbitrary angle toward a charged body if necessary, a connecting device letting the ions generated at the window positioned inside of the body of the ionizer emit toward the charged body by connecting one end of the flexible tube and the head unit, and a connecting device connecting the other end of the flexible tube and the body of the ionizer. The high voltage power lines in the flexible tube are molded to prevent short circuits occurring at a near distance between the high voltage power lines and mutual induction voltages occurring. The short circuit and the mutual induction voltage are caused by the mutual influence of the high voltage lines.

As prior arts of this field, there are two Korean patents. One of them is a patent application having a filing number 10-2003-56410 filed by the applicant of this invention and the other is a patent having a registration number 10-0465346 of Hamamatsu Photonics Co., Ltd of Japan.
As shown in said cited references, it was very difficult to install the electrostatic eliminator according to the prior arts at the limited space. And it was difficult to change the installed position according to the change of the production line.
The biggest problem was a limited space and the next ones were that removal and reinstalling of them were not easy. Moreover it was difficult to fix the installation angle in order that the ions from the head unit are emitted toward the charged body exactly. Therefore, generally it was installed on the ceiling by using a specially prepared bracket, but installing by readjusting the position of a number of electrostatic eliminators one by one in production line was very difficult.
The main reason was the head from which the +ions and −ions come out toward the charged body was attached at the body i.e. the case of the electrostatic eliminator as one body. Accordingly it was impossible to solve this problem actually with the structure of the prior electrostatic eliminator.
For these reasons, efforts to solve this problem has been made at the semiconductor factories, LCD production lines, PDP production lines, OLED production lines and the like, but no radical solution has been found so far.
Meanwhile the X-ray is divided into soft X-ray and hard X-ray according to the material permeability, the soft X-ray has low permeability and is absorbed easily though the air space is thin and the hard X-ray has high permeability and is used in taking a Roentgen photograph.
The energy of the soft X-ray is very low (approximately 1/3,000 of that of the hard X-ray) so the permeability is very low and it is absorbed mostly in the air.


This invention is a portable electronic device (100) including a display (212), an input device (210), a lighting circuit (204), a light sensor (206) and a control circuit (208). The lighting circuit (204) includes a light source (214) to illuminate the display (212) and the input device (210). The light sensor (206) determines the ambient lighting conditions about the display (212) and/or the input device (210) and generates an ambient lighting signal based on the ambient lighting conditions. The control circuit (208) is coupled to the lighting circuit (204) and the light sensor (206) and has a delayed operation mode in which a first activation of the input device (210) illuminates the display (212) without performing any other operation of the device (100) and a second activation of the input device performs an operation of the device other than illuminating the display. The control circuit (208) of the portable electronic device (100) may receive a reverse bias signal generated by the lighting circuit (204) when incident with ambient lighting about the user interface (202) to supplement or eliminate the light sensor (206).

A user interface for a portable electronic device includes an input device, such as a keypad, for data input by a user and a flat-panel display for information output to the user. A portable electronic device has an increasing number of features and, as a result, requires more frequent interaction and use of its keypad and display. These features include Internet access, personal organizer functions, entertainment programs, audio player functions (such as MP3 and AM/FM radio), A/V player functions (such as video streaming and video conferencing), calculator functions and a host of other possibilities. As such, the backlighting system for the display and the keypad is activated and remains on for as long as the keypad receives input from the user. When keypad activity is not detected for a particular period of time, such as 15 seconds or so, the backlighting system for display and keypad will deactivate. However, the user has no real need for activating the backlighting system when the ambient lighting conditions are sufficient to view the display and keypad. Thus, in an environment that has sufficient ambient lighting, backlighting becomes a wasteful drain on the battery of the device.
Devices having circuitry for adjusting the luminance of a display based on ambient lighting conditions are known. Such device includes a liquid crystal display, a backlighting source adjacent to the display, and an ambient light sensor coupled to the backlighting source. The backlighting source adjusts the luminance of the liquid crystal display based on the ambient lighting conditions detected by the ambient light sensor. These devices are more energy efficient than systems that turn-on the backlighting source and stay-on for a predetermined time period whenever keypad activity is detected.
Typically, a user has difficulty viewing the display and keypad of the portable electronic device in areas of low lighting or total darkness. In such case, a keystroke is necessary to activate the backlighting system so that the user will be able to read the display and keypad. Unfortunately, the keystroke activates an operation of the device as well as activating the backlighting system. In many cases, the device executes an undesirable operation (such as entering a character on the display), particular since the user could not see the keypad when the keystroke was made. Subsequently, the user must clear the undesired entry in order to continue, thus causing counter-productive keystrokes and wasteful drain on the battery due to these extra keystrokes.
Accordingly, there is a need for a portable electronic device that operates effectively for a user in low lighting or complete darkness. In particular, the device should permit the user to activate a button on its keypad merely to turn-on the backlighting system without performing any other operation of the device. For keystrokes entered soon thereafter, the keypad should operate the device as it normally would when there is more ambient lighting. With such a device, the user would not worry about entering characters or activating functions when he or she cannot see the display. There is also a need for a portable electronic device having a backlighting system that illuminates an input device in addition to, or separate from, a display based on ambient lighting conditions in order conserve energy consumption. There is a further need for a portable electronic device having a backlighting system that detect ambient lighting conditions without requiring a light sensor in order to minimize cost and/or the size of the device. The present invention fulfills these needs and provides other benefits as will be apparent from the description herein.

Display and keypad backlight management for portable electronic devices


An anti-theft device for a vehicle includes a casing engaged in a housing, a sleeve extended upward from the housing for receiving a lock, a rod having one end rotatably coupled to the casing and the other end slidably engaged in a tube, a ring element pivotally coupled to the tube, and a shank engaged through the housing and the casing so as to form the anti-theft device. The device has a simplified configuration and has a greatly lowered manufacturing cost.

(a) Field of the Invention
The present invention relates to an anti-theft device, and more particularly to an anti-theft device for a vehicle.
(b) Description of the Prior Art
Various kinds of anti-theft devices have been developed for locking the foot pedal and the steering wheel or for locking the steering wheel and the gear shift. However, the anti-theft devices have a complicated configuration and thus have an increased manufacturing cost.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional anti-theft devices for vehicles.


Under software control, a loss of clock detect circuit (24) can be enabled to detect loss of clock. A plurality of different clock signals, including the input reference clock (34) to the PLL (12) and the feedback (36) from the PLL (12), are monitored by the loss of clock circuit (24). When the currently selected system clock (38) signal is lost, a control circuit (28) can select an optimal back-up clocking mode based on which clock signals were lost. One such selectable mode is to utilize the input reference clock (34) directly instead of the PLL (12). Another such selectable mode is to utilize the PLL (12) in a self-clocked mode to provide the system clock (38).

System clocks are necessary for the operation of microprocessors and microcontrollers. In many instances, loss of a system clock causes the microcontroller or microprocessor to stop. However, this is not acceptable or practical in certain situations. In particular, in control applications where a microcontroller is being used to govern the operation of a system, it is often essential that the system continues to operate so that it can go to a known state despite a loss of clock. One example of this is in an automotive engine controller, where an engine must be allowed to continue to operate even if the primary clock is lost.
As noted, the most basic answer to a loss of system clock is to take no further action, stopping of the microprocessor or microcontroller, and leaving the system nonoperational. One solution for keeping the microprocessor/microcontroller operating after losing the system clock is to monitor the output of the system clock and to switch to a free-running RC oscillator upon loss of the system clock. This approach has several problems. One problem is that such a free-running RC oscillator requires increased chip area, consumes more power, and adds complexity. Another problem is that it is hard to control the frequency of such RC oscillators due to manufacturing process variations. With this solution, it is also impossible to distinguish between actual external reference clock failure and failure of the phase locked loop (PLL).
Another solution is to monitor the PLL's reference clock but not to alter the source of the system clock upon a reference failure. Instead, the voltage controlled oscillator (VCO) of the PLL is driven by a relatively constant voltage, which produces a fixed output frequency from the PLL, when the system clock is lost. One problem with this approach is that only one clock source is actually being monitored. Thus, it is impossible to determine whether or not the failure was in the reference clock or in the PLL itself. Also, if the PLL is the source which is not operational, then the system itself remains nonoperational.

Method and apparatus for managing failure of a system clock in a data processing system


The present invention provides an output buffer 38 for the signal from a bit line 16 that is precharged by a precharging gate 34. The output buffer 38 comprises a stack of field effect transistors made up of an isolation transistor 40 switched by a clock signal indicating the precharge period, a precharge state driver transistor 42 and a non-precharge state driver transistor 44. The non-precharge state driver transistor 44 is connected directly between the output signal line of the output buffer and the ground. The two driver transistors 42,44 are of different polarities and are switched by the bit line signal. In operation, during the precharge period, the precharge state driver transistor 42 is disabled from changing the output of the output buffer 38 by the isolation transistor 40 whilst the non-precharge state driver transistor 44 is disabled by the transition to or maintenance of the precharge signal value on the bit line 16.

1. Field of the Invention
The present invention relates to data processing apparatus, and in particular to data processing apparatus including memory cells accessed via bit lines.
2. Description of the Prior Art
It is known in the field of data processing systems to provide a memory, such as registers within a register bank, a cache memory or main memory, with bit lines running through the memory and via which data values are recovered from a chosen data storage cell within the memory. The bit lines within such memory are typically precharged during a precharge cycle to a given voltage and then selectively discharged by the chosen data storage cell in dependence upon whether the data storage cells is holding a "0" or a "1". A problem associated with bit lines is that they have a relatively large capacitance and so can take a comparatively long time to precharge and then selectively discharge. This can limit the cycle time of the system. In addition, when reading data values from data storage cells, it is important that they should be available and well defined by a certain point within the processing cycle. For these reasons, the length of time the bit line can spend bearing a signal value moving between those representing a well defined "0" or "1" is a problem.
In order to resolve some of these problems it is known to use tri-state output buffers at the outputs of a bit line such that the signal value on the bit line can be captured at a well defined time and variations of the signal value following the time at which the tri-state buffer can be prevented from influencing the output signal downstream of the tri-state buffer.
It is a constant aim within data processing systems to reduce the power consumption of the processors and the size of the circuits required. Low power consumption is highly desirable to extend battery life in portable systems and to allow faster operation without overheating.
FIGS. 1A, 1B, 2A and 2B of the accompanying drawings illustrate a tri-state output buffer 4. A bit line 2 connected to data storage cells (not shown) provides an input to the tri-state buffer 4. The tri-state buffer 4 is formed of a stack of four field effect transistors connected between the supply rail voltage and ground. The two transistors 6,8 nearest the supply voltage are p-type transistors. The two transistors 10,12 nearest the ground voltage are n-type transistors. Upstream of the tri-state buffer 4 is a storage element 14 formed of two inverters. the transistors 8,10 are supplied respectively when an enable signal that is low for the precharge phase of the clock cycle for the p-type transistors 8 and high for the n-type transistors 10. These two transistors 8,10 accordingly serve to isolate the signal on the bit line 2 from the storage element 14 during the precharge cycle. The transistors 6,12 serve as an inverter when the tri-state buffer 4 is not in its high impedance state to pass the bit line signal to the storage element 14.
FIG. 1A shows the tri-state buffer 4 in its transmissive state with the transistors 8,10 switched on. In this case a bit line signal value of "1" turns on the transistor 12 and turns off the transistor 6. Thus, a output signal value of "0" is passed to the input of the storage element 14. The output from the storage element 14 is inverted compared to its input and so the storage element output signal is a "1" that correctly reflects the bit line signal value.
FIG. 1B shows the tri-state buffer 4 in its transmissive condition with in this case a bit line signal value of "0". The transistors 8,10 are again switched on. The bit line signal value "0" in this case turns on the transistor 6 whilst the transistor 12 is switched off.
FIG. 2A shows the tri-state buffer 4 with the transistors 8,10 in this case switched off by the enable signals that indicate that the system is in the precharge phase of the clock cycle rather than in the read phase illustrated in FIGS. 1A and 1B. Thus, as the signal value of the bit line 2 changes from a "1" to a "0", this is not passed on to the storage element 14 which maintains its input and output values as shown in FIG. 2A.
Whilst the tri-state buffer 4 discussed above serves well in accurately capturing a bit line signal value and a known time and rendering the output immune to changes during the precharge phase, it suffers from the disadvantage of requiring two clock inputs to each tri-state buffer 4. In the context of a memory system, there are very many bit lines 2 being simultaneously read. Accordingly, the structures described above are repeated many times, for example in a register bank having 32-bit words and three read ports, this would result in 96 such tri-state buffers 4 being required. The physical space required for the six clock signal lines for these 96 tri-state buffers would require a significant circuit area. Furthermore, the need to drive the clock signal values on all of these clock lines and switch two transistors 8,10 within each tri-state buffer 4 consumes a disadvantageous amount of power.


An image signal generation unit comprises a horizontal pixel number conversion unit for performing the conversion of horizontal direction pixels corresponding to horizontal scanning period of NTSC system, for digital image data of the chrominance difference having the picture element number configuration based on the VGA standard, and a liquid crystal encoder for generating the primary color group digital image data RGB from digital image data YUV processed by the horizontal pixel number conversion unit, and output them directly on a liquid crystal display.

A digital camera has an encoder circuit for generating, from YUV signals obtained by imaging, analog video signals or RGB signals for external output, and analog RGB signals for driving a liquid crystal finder. The analog RGB signals for driving the liquid crystal finder are generated by sampling the analog video signals or the RGB signal for external output at a sampling rate corresponding to the number of pixels of a liquid crystal finder.
Unexamined Japanese Patent Applications KOKAI Publication 2001-054134 discloses another type of an encoder circuit which generates, together with analog video signals for external output, and digital RGB signals to be directly supplied to the driving circuit of a TFT liquid crystal display panel constituting the liquid crystal finder.
Image data obtained by imaging in general have a VGA (Video Graphics Array) based pixel configuration of 480 vertical pixels×640 horizontal pixels, which is actually the defacto standard of image processing.
In the case, the video signals to be externally output for Japan's standard television system NTSC are generated from the image data having the VGA pixel number, image data having 704 pixels are generated by multiplying the horizontal pixel number of the VGA by 11/10, by sampling the image data at a frequency of 13.5 MHz derived from the scanning time for one horizontal line. The image data with the horizontal pixel number increased for external output are sampled by a sampling frequency matching with the number of pixels constituting the liquid crystal display panel, and then drives the liquid crystal display with the image data. Ultimately, an image having the VGA aspect ratio of 3:4 is displayed on the liquid crystal display pane.
As described above, the video signals for external output and the signals for liquid crystal display of the finer require each different horizontal pixel numbers, without any correlation between the two pixel numbers. The problem is that the size has to be large of an encoder circuit capable of generating, and outputting, video signals and liquid crystal display signals out of image data provided from the imaging system.
The above-quoted literature fails to disclose anything about the actual number of pixels, etc. relative to the digital RGB signals to be generated.

Image signal generation unit, digital camera, and image signal generation method


A process for producing high density detergent compositions is provided. The process is a continuous process during which high density detergent agglomerates are produced by feeding a surfactant paste and dry starting detergent material into a moderate speed mixer/densifier having a centrally positioned rotating shaft and at least one high speed chopper. The surfactant paste is inputted at least one location along the length of the moderate speed mixer/densifier to achieve optimal build-up agglomeration. The proces produces a free flowing, high density detergent composition which can be commercially sold as a low dosage or xe2x80x9ccompactxe2x80x9d detergent composition.

The present invention generally relates to a process for producing high density detergent compositions having improved physical properties. More particularly, the invention is directed to a continuous process during which high density detergent agglomerates are produced by feeding a surfactant paste and dry starting detergent material directly into a cylindrically-shaped/moderate speed mixer/densifier having a centrally positioned rotating shaft and at least one high speed chopper or cutter. The process produces an improved free flowing, high density detergent composition with a narrow particle size distribution which can be commercially sold as a low dosage or xe2x80x9ccompactxe2x80x9d detergent composition.
Recently, there has been considerable interest within the detergent industry for laundry detergents which are xe2x80x9ccompactxe2x80x9d and therefore, have low dosage volumes. To facilitate production of these so-called low dosage detergents, many attempts have been made to produce high bulk density detergents, for example with a density of 600 g/l or higher. The low dosage detergents are currently in high demand as they conserve resources and can be sold in small packages which are more convenient for consumers.
Generally, there are several types of processes by which detergent granules or powders can be prepared. One type of process involves spray-drying an aqueous detergent slurry in a spray-drying tower to produce highly porous spray dried particulate material. In another type of process, various detergent components are dry mixed after which they are combined together with a binder such as a nonionic or anionic surfactant. In both processes, the most important factors which govern the density of the resulting detergent granules are the density, porosity and surface area of the various starting materials and their respective chemical composition. These parameters, however, can only be varied within a limited range. Thus, a substantial bulk density increase can only be achieved by additional processing steps which lead to densification of the detergent granules.
There have been many attempts in the art for providing processes which increase the density of detergent material. Particular attention has been given to densification of spray-dried particulate material by post tower treatment. For example, one attempt involves a batch process in which spray-dried or granulated detergent powders containing sodium tripolyphosphate and sodium sulfate are densified and spheronized in a Marumerizer(copyright). This apparatus comprises a substantially horizontal, roughened, rotatable table positioned within and at the base of a substantially vertical, smooth walled cylinder. This process, however, is essentially a batch process and is therefore less suitable for the large scale production of detergent powders. Other attempts have been made to provide a continuous processes for increasing the density of xe2x80x9cpost-towerxe2x80x9d or spray dried particulate material.
All of the aforementioned processes are directed primarily to densifying or otherwise processing spray dried particulate material. Currently, the relative amounts and types of materials subjected to spray drying processes in the production of detergent granules has been limited. For example, it has been difficult to attain high levels of surfactant in the resulting detergent composition, a feature which facilitates production of low dosage detergents. Thus, it would be desirable to have a process by which detergent compositions can be produced without having the limitations imposed by conventional spray drying techniques. To that end, the art is also replete with disclosures of processes which entail agglomerating detergent compositions. For example, attempts have been made to agglomerate detergent builders by mixing zeolite and/or layered silicates in a mixer to form free flowing agglomerates.
However, in all of the aforementioned processes, continuous large-scale production has its difficulties, especially relative to obtaining acceptable product consistently and with minimal wear and tear on the manufacturing equipment. For instance, while certain mixer/densifiers work extremely well at the lab scale, their performance is not always reproducible in large-scale commercial continuous manufacturing facilities. One problem experienced with large-scale detergent manufacturing using the aforementioned processes involves detergent product that has a wide particle size range. This, in effect, produces a detergent product having some xe2x80x9cundersizedxe2x80x9d or very xe2x80x9cfinexe2x80x9d particles and some very large or xe2x80x9coversizedxe2x80x9d particles which is not only unacceptable to the consumer, but leads to product performance inconsistencies. Specifically, a particular dose or scoop of detergent product used by the consumer may not have the targeted ingredient levels because a disproportionate amount of xe2x80x9cfinesxe2x80x9d or xe2x80x9coversxe2x80x9d is in the dose as a result of the settling of the fines to the bottom of the product box during storage and handling. This inevitably leads to undesirable cleaning performance, and at a minimum, inconsistencies including performance. One solution to this problem is simply to recycle the xe2x80x9cfinesxe2x80x9d and grind the xe2x80x9coversxe2x80x9d to the desired size, but this increases the manufacturing costs significantly.
Another problem that has arisen involves excessive vibration of the rotating shafts in commercial scale mixer/densifiers, especially in large moderate speed mixer/densifiers, which can have deleterious effects on the detergent composition produced as well as on the mixer/densifiers and other closely located manufacturing equipment. This problem can also lead to structural damage to the manufacturing building for which substantial expenditures may be required for repairs. The use of additional mechanical apparatus such as tuned dampers positioned on the shaft only add to the cost of manufacturing and can interfere its with operation in that the tuned damper apparatus inside the mixer provides a place for detergent to accumulate, thereby deleteriously affecting mixer operation. Thus, there remains a need for a means by which commercial scale moderate speed mixer/densifiers used to produce low dosage, high density detergent compositions can be operated continuously without significant mechanical vibration and damage resulting therefrom.
Accordingly, there remains a need in the art to have a process for continuously producing a high density detergent composition which has improved physical properties including a more narrow particle size distribution. There is also a need for such a process that involves a moderate speed mixer/densifier that experiences minimal mechanical vibration, and yet, produces a superior detergent composition. Also, there remains a need for such a process which is more efficient and economical to facilitate large-scale production of low dosage or compact detergents.
The following references are directed to densifying spray-died particulate material: Appel et al, U.S. Pat. No. 5,133,924 (Lever); Bortolotti et al, U.S. Pat. No. 5,160,657 (Lever); Johnson et al, British patent No. 1,517,713 (Unilever); and Curtis, European Patent Application 451,894. The following references are directed to producing detergents by agglomeration: Capeci et al, U.S. Pat. No. 5,366,652; Capeci et al, U.S. Pat. No. 5,486,303; Capeci et al, U.S. Pat. No. 5,489,392; Capeci et al, U.S. Pat. No. 5,516,448; Beerse et al, U.S. Pat. No. 5,108,646 (Procter and Gamble). Other relevant prior art includes: PCT Publication WO 98/14558; PCT Publication WO 98/14557; PCT Publication WO 98/14556; PCT Publication WO 98/14553; PCT Publication WO 98/14552; PCT Publication WO 98/14555; PCT Publication WO 98/1454; PCT Publication WO 98/1455 1; and PCT Publication WO 98/11193 and WO 98/24876.
The present invention meets the aforementioned needs in the art by providing a process which continuously produces a high density detergent composition via a process during which high density detergent agglomerates are produced by feeding a surfactant paste and dry starting detergent material into a cylindrically-shaped/moderate speed mixer/densifier having a centrally positioned rotating shaft and at least one high speed chopper. In the process, surfactant paste and other dry starting detergent materials are inputted directly into the moderate speed mixer/densifier to form detergent agglomerates which are then cooled and/or dried. Importantly, the surfactant paste is inputted along the length of the moderate speed mixer/densifier to ensure optimal build-up agglomeration. The resulting agglomerates from the process are free flowing, more uniform in size and shape, and higher in surfactant level and are ready for incorporation into a commercially viable low dosage or xe2x80x9ccompactxe2x80x9d detergent product.
As used herein, the term xe2x80x9cagglomeratesxe2x80x9d refers to particles formed by build-up agglomeration of starting detergent ingredients typically having a smaller mean particle size than the formed agglomerates. All percentages and ratios used herein are expressed as percentages by weight (anhydrous basis) unless otherwise indicated. All documents are incorporated herein by reference. All viscosities referenced herein are measured at 70xc2x0 C. (xc2x15xc2x0 C.) and at shear rates of about 10 to 100 secxe2x88x921.
In accordance with one aspect of the invention, a process for preparing a crisp, free flowing, high density detergent composition is provided. The process comprises the steps of: (a) continuously adding a detergent surfactant paste and dry starting detergent material into a moderate speed mixer/densifier to form detergent agglomerates, wherein the moderate speed mixer/densifier includes a centrally rotating shaft and at least one high speed chopper located on the inside wall along the longitudinal length of said moderate speed mixer/densifier, wherein said surfactant paste is inputted along said longitudinal length of said moderate speed mixer/densifier; and (b) drying or cooling the detergent agglomerates so as to form the detergent composition. In another aspect of the invention, an acid precursor to a detergent surfactant is used in place of the surfactant paste to provide the detergent composition in agglomerate form.
In yet another aspect of the invention, another process for continuously preparing a detergent composition is provided. This process comprises the steps of: (a) continuously adding dry starting detergent material into a mixer to mixed dry detergent material; (b) inputting mixed dry detergent material and a detergent surfactant paste into a moderate speed mixer/densifier to form detergent agglomerates, wherein moderate speed mixer/densifier includes a centrally rotating shaft and at least one high speed chopper located on the inside wall along the longitudinal length of moderate speed mixer/densifier, wherein surfactant paste is inputted along longitudinal length of moderate speed mixer/densifier so as to mix with mixed dry detergent material after mixed dry detergent material enters moderate speed mixer/densifier; and (c) drying or cooling the detergent agglomerates so as to form the detergent composition.
Accordingly, it is an advantage of the invention to provide a process for continuously producing a high density detergent composition using a moderate speed mixer/densifier which experiences less vibration and produces a composition having a more narrow particle size distribution. Also, it is an advantage of the invention to provide such a process which is more efficient and economical to facilitate large-scale production of low dosage or compact detergents. These and other objects, features and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiments and the appended claims.
The present process can be used in the production of low dosage, high density detergent compositions containing agglomerates produced directly from dry starting detergent ingredients and a surfactant paste or precursor thereof. It has been surprisingly found that by using a single moderate speed mixer/densifier, a superior detergent composition in the form of agglomerates can be produced. The resulting detergent agglomerates have a tighter or more narrow particle size distribution which leads to the need for less recycling of undersized agglomerates back through the mixer/densifier and/or the need to grind oversized detergent agglomerates. Additionally, by inputting the surfactant paste or precursor thereof directly into the moderate speed mixer/densifier along its longitudinal length, sufficient mixing for rapid build-up agglomeration occurs. The resulting detergent agglomerates are also more spherical in appearance which is aesthetically desirable for modern day compact detergent products. Further, the process only requires one moderate speed mixer/densifier to produce the final detergent composition which is more economical than previous multi-step mixer processes.
In the first step of the process, the invention entails continuously mixing into a moderate speed mixer/densifier at least two streams of starting detergent ingredients including a surfactant paste stream and a dry starting detergent material stream. The surfactant paste added to the moderate speed mixer/densifier is in aqueous paste form and is added in amounts of from about 25% to about 65%, preferably from about 35% to about 55% and, most preferably from about 38% to about 44%, by weight of the total input stream to the mixer/densifier. Preferably, the dry starting detergent material comprises from about 20% to about 50%, preferably from about 25% to about 45%, and most preferably from about 30% to about 40%, of an aluminosilicate or zeolite builder, and from about 10% to about 40%, preferably from about 15% to about 30%, and most preferably from about 15% to about 25%, by weight of a sodium carbonate. The dry starting detergent material preferably is not a spray-dried particulate material, and does not contain a detergent surfactant.
While not intending to be bound by theory, it is believed that by inputting surfactant paste along the longitudinal length of a cylindrically-shaped moderate speed mixer/densifier having a centrally rotating shaft to which one or more of a variety of agglomeration tools are attached and at least one high speed chopper located on the inside wall of the mixer/densifier, optimal build-up agglomeration results. In preferred modes of the process, several high speed choppers are used in the moderate speed mixer/densifier, for example, at least two, preferably at least four, and most preferably at least six high speed choppers are used. Certain moderate speed mixer/densifiers can be equipped with as many as twelve high speed choppers to improve build-up agglomeration. Also, various multi-blade configurations can be used on the high speed choppers to optimize their effectiveness. The tip speed of any one of these choppers is preferably from about 1 m/s to about 60 m/s, more preferably from about 10 m/s to about 45 m/s, and most preferably from about 20 m/s to about 30 m/s. As those skilled in the art will appreciate, the tip speed can be adjusted with a variable speed drive apparatus connected to the high speed choppers. The rotational speed of any one of these choppers is preferably from about 200 rpm to about 5000 rpm, more preferably from about 1500 rpm to about 4500 rpm, and most preferably from about 3000 rpm to about 4000 rpm.
By inputting the surfactant paste near, preferably within 25 cm or less from the high speed choppers, it has been found that even more optimal build-up agglomeration occurs. Most optimal results are achieved by ensuring that at least 80% of the surfactant paste is added into the face of, underneath, or from within the high speed choppers. The resulting detergent agglomerates have the previously mentioned characteristics of a more narrow particle size distribution, more spherical-shaped agglomerates, and even have the ability to contain higher levels of surfactant. The higher level of surfactant in the detergent agglomerates is extremely beneficial as it allows for additional detergent ingredients to be added to the composition without sacrificing density or the degree of compactness of the detergent product.
Previous agglomeration processes which employ a high speed mixer for mixing the surfactant or precursor thereof and dry detergent material prior to the moderate speed mixer/densifier typically do not provide the desired narrow particle size distribution. In fact, such processes produce a substantial amount of undersized or fine particles which are recycled back through the process. It is not uncommon for 50% by weight of the agglomerates produced in such prior processes to require recycling and/or grinding to provide the desired mean particle size. In that regard, the present process dramatically reduces the amount of undersized and oversized detergent agglomerates produced which renders the process more efficient, economical and flexible. The particle size distribution is also more narrow. Specifically, the mean particle size of the agglomerates is preferably from about 150 microns to about 2000 microns, more preferably from about 250 microns to about 1000 microns, and most preferably from about 300 microns to about 500 microns.
Preferably, the surfactant paste and the dry starting detergent material are continuously added to the moderate speed mixer/densifier in weight ratio ranges described herein so as to ensure production of the desired free flowing, crisp, high density detergent composition. Preferably, the weight ratio of the surfactant paste to the dry starting detergent material is from about 1:10 to about 10:1, more preferably from about 1:4 to about 4:1 and, most preferably from about 2:1 to about 2:3.
The moderate speed mixer/densifier used in the present process includes liquid distribution and agglomeration tools so that both techniques can be carried forth simultaneously. As described, the liquid or paste distribution is accomplished with the use of at least one high speed chopper positioned on the inside wall along the length of the moderate speed mixer/densifier. For purposes of ensuring effective liquid or surfactant paste distribution and adequate build-up agglomeration, the high speed chopper preferably has a tip speed as mentioned above. To further facilitate build-up agglomeration, the moderate speed mixer/densifier is equipped with ploughs and/or other tools to ensure effective build-up agglomeration in the process. It is preferable to have the moderate speed mixer/densifier to be, for example, a Lxc3x6dige KM (Ploughshare) mixer, Drais(copyright) K-T 160 mixer or similar brand mixer. The mean residence time in the moderate speed mixer/densifier is typically from about 0.1 minutes to about 20 minutes, most typically the residence time is about 0.5 minutes to about 10 minutes, wherein the mean residence time is conveniently and accurately measured by measuring the steady-state weight of the mixer/densifier (Kg) and dividing by the throughput (Kg/hr) of the mixer.
The process also exhibits reduced mechanical vibration in the moderate speed mixer/densifier. While not intending to be bound by theory, it is believed that the detergent surfactant paste input along the length of the moderate speed mixer/densifier, through for example, an input tube or nozzle, leads to a reduction of detergent material build-up on the inside wall of the moderate speed mixer/densifier. The detergent material xe2x80x9cwallxe2x80x9d that typically forms in prior art processes frequently causes a weight imbalance during mixer operation leading to undesirable mechanical vibration, especially of the centrally rotating shaft in the moderate speed mixer/densifier. By using the instant process, the preferred peak vibration range for the shaft is from about xe2x88x921.0 G to about 1.0 G, more preferably from about xe2x88x920.5 G to about 0.5 G, and most preferably from about xe2x88x920.25 G to about 0.25 G, in a frequency range of from about 10 Hz to about 20 Hz as measured at the mid-span length of the shaft. Such peak vibration ranges represent a dramatic improvement over peak vibrations typically experienced in commercial scale manufacturing facilities which can be on the order of xc2x13.5 G. The peak vibration is preferably measured using 90 second intervals. As those skilled in the art will appreciate, such peak vibration measurements are easily completed using a conventional accelerometer (available from PCB 308B ICP Company, Buffalo, N.Y.).
For example, during continuous operation of the process, the vibration of shaft is recorded using the accelerometer attached to a power supply (e.g., PCB 480E090 from ICP Company, and a battery operated digital tape recorder such as the Sony TCD-D3 DAT recorder). The recorder and power supply are mounted in a waterproof, shock proof enclosure (such as the Carlon CJ1085 Enclosure). The sensor is attached to the shaft by means of dental cement or other rigid adhesive and is positioned such that radial shaft vibration is measured. The vibration is recorded for at least 2 hours, preferably for 4 hours. Upon completion of the run, the tape recorder is removed from the enclosure and played back. The data is plotted in 90 second intervals on either a digital or analog plotting device (such as the Hewlett-Packard 3560A or 35670A analyzers). The peak and rms values of the vibration can be determined from a PC-based software program such as Excel or Matlab.
While not intending to be bound by theory, the negative peak vibrations associated with the moderate speed mixer/densifier are especially exacerbated when the so-called xe2x80x9cdetergent wallxe2x80x9d is present on the inner surface of the moderate speed mixer/densifier. During the process, an optional detergent coating or wall of at least about a 1 mm can cover a portion of the inner wall surface of the moderate speed mixer/densifier. The portion of the inner wall covered by this coating having a minimum thickness of 1 mm can be substantial (up to 100% of the inner surface covered) or a mere 50% can be covered. The presence of this detergent coating provides an irregular surface contour against which the ploughs are contacted during rotation of the shaft of the moderate speed mixer/densifier. This irregular surface results in the shaft being subjected to irregular forces, thereby further enhancing the overall mechanical vibration. This process wherein the detergent surfactant paste is added directly to, and along the length of the moderate speed mixer/densifier, however, eliminates or minimizes this additional mechanical vibration.
The preferred density of the resulting detergent agglomerates exiting the moderate speed mixer/densifier is at least about 650 g/l, more preferably from about 700 g/l to about 900 g/l. The particle porosity of the resulting detergent agglomerates of the composition is preferably in a range from about 5% to about 20%, more preferably at about 10%. The detergent agglomerates can be dried in a fluid bed dryer or cooled in a fluid bed cooler or similar apparatus which are well known in the art. While the detergent agglomerates exiting the moderate speed mixer/densifier and fluid bed cooler or dryer are ready for packaging and sale as a low dosage, compact detergent product at this point, they can be subjected to one or more optional processing steps.
Optionally, a mixer may be used to pre-mix the starting dry detergent materials. Any suitable mixer can be used for such purposes including but not limited to a Shugi Granulator or a Lxc3x6dige CB 30 mixer. Another optional process step involves adding a coating agent to improve flowability and/or minimize over agglomeration of the detergent composition in one or more of the following locations of the instant process: (1) the coating agent can be added directly into the fluid bed cooler or fluid bed dryer if used; (2) the coating agent may be added between the fluid bed dryer and the fluid bed cooler if both are used; (3) the coating agent may be added between the fluid bed dryer or cooler and the moderate speed mixer/densifier; and/or (4) the coating agent may be added directly to the moderate speed mixer/densifier. It should be understood that the coating agent can be added in any one or a combination of locations mentioned herein. The coating agent is preferably added into the moderate speed mixer/densifier as well as into the fluid bed dryer.
The coating agent is preferably selected from the group consisting of aluminosilicates, silicates, carbonates and mixtures thereof. The coating agent not only enhances the free flowability of the resulting detergent composition which is desirable by consumers in that it permits easy scooping of detergent during use, but also serves to control agglomeration by preventing or minimizing over agglomeration, especially when added directly to the moderate speed mixer/densifier. As those skilled in the art are well aware, over agglomeration can lead to very undesirable flow properties and aesthetics of the final detergent product.
Optionally, the process can comprises the step of spraying an additional binder in the moderate speed mixer/densifier and/or in the fluid bed dryer or cooler. A binder is added for purposes of enhancing agglomeration by providing a xe2x80x9cbindingxe2x80x9d or xe2x80x9cstickingxe2x80x9d agent for the detergent components. The binder is preferably selected from the group consisting of water, anionic surfactants, nonionic surfactants, polyethylene glycol, polyvinyl pyrrolidone polyacrylates, citric acid and mixtures thereof. Other suitable binder materials including those listed herein are described in Beerse et al, U.S. Pat. No. 5,108,646 (Procter and Gamble Co.), the disclosure of which is incorporated herein by reference.
Other optional steps contemplated by the present process include screening the oversized and undersized detergent agglomerates in a screening apparatus which can take a variety of forms including but not limited to conventional screens chosen for the desired particle size of the finished detergent product. Another optional step of the instant process entails finishing the resulting detergent agglomerates by a variety of processes including spraying and/or admixing other conventional detergent ingredients. For example, the finishing step encompasses spraying perfumes, brighteners and enzymes onto the finished agglomerates to provide a more complete detergent composition. Such techniques and ingredients are well known in the art.
The detergent surfactant paste used in the process is preferably in the form of an aqueous viscous paste, other forms are also contemplated by the invention, such as the acid precursor of a surfactant paste. If an acid precursor is used, the dry detergent material will include a neutralizing agent such as sodium carbonate. The viscous surfactant paste used herein has a viscosity of from about 5,000 cps to about 100,000 cps, more preferably from about 10,000 cps to about 80,000 cps, and contains at least about 10% water, more preferably at least about 20% water. The viscosity is measured at 70xc2x0 C. and at shear rates of about 10 to 100 secxe2x88x921. Furthermore, the surfactant paste, if used, preferably comprises a detersive surfactant in the amounts specified previously and the balance water and other conventional detergent ingredients.
The surfactant itself, in the viscous surfactant paste, is preferably selected from anionic, nonionic, zwitterionic, ampholytic and cationic classes and compatible mixtures thereof. Detergent surfactants useful herein are described in U.S. Pat. No. 3,664,961, Norris, issued May 23, 1972, and in U.S. Pat. No. 3,919,678, Laughlin et al., issued Dec. 30, 1975, both of which are incorporated herein by reference. Useful cationic surfactants also include those described in U.S. Pat. No. 4,222,905, Cockrell, issued Sep. 16, 1980, and in U.S. Pat. No. 4,239,659, Murphy, issued Dec. 16, 1980, both of which are also incorporated herein by reference. Of the surfactants, anionics and nonionics are preferred and anionics are most preferred.
Nonlimiting examples of the preferred anionic surfactants useful in the surfactant paste include the conventional C11-C18 alkyl benzene sulfonates (xe2x80x9cLASxe2x80x9d), primary, branched-chain and random C10-C20 alkyl sulfates (xe2x80x9cASxe2x80x9d), the C10-C18 secondary (2,3) alkyl sulfates of the formula CH3(CH2)x(CHOSO3xe2x88x92M+)CH3 and CH3(CH2)y(CHOSO3xe2x88x92M+)CH2CH3 where x and (y+1) are integers of at least about 7, preferably at least about 9, and M is a water-solubilizing cation, especially sodium, unsaturated sulfates such as oleyl sulfate, and the C10-C18 alkyl alkoxy sulfites (xe2x80x9cAExSxe2x80x9d; especially EO 1-7 ethoxy sulfates).
Optionally, other exemplary surfactants useful in the paste of the invention include and C10-C18 alkyl alkoxy carboxylates (especially the EO 1-5 ethoxycarboxylates), the C10-18 glycerol ethers, the C10-C18 alkyl polyglycosides and their corresponding sulfated polyglycosides, and C12-C18 alpha-sulfonated fatty acid esters. If desired, the conventional nonionic and amphoteric surfactants such as the C12-C18 alkyl ethoxylates (xe2x80x9cAExe2x80x9d) including the so-called narrow peaked alkyl ethoxylates and C6-C12 alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C12-C18 betaines and sulfobetaines (xe2x80x9csultainesxe2x80x9d), C10-C18 amine oxides, and the like, can also be included in the overall compositions. The C10-C18 N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples include the C12-C18 N-methylglucamides. See WO 9,206,154. Other sugar-derived surfactants include the N-alkoxy polyhydroxy fatty acid anodes, such as C10-C18 N-(3-methoxypropyl) glucamide. The N-propyl through N-hexyl C12-C18 glucamides can be used for low sudsing. C10-C20 conventional soaps may also be used. If high sudsing is desired, the branched-chain C10-C16 soaps may be used. Mixtures of anionic and nonionic surfactants are especially useful. Other conventional useful surfactants are listed in standard texts.
The starting dry detergent material of the present process preferably comprises a detergent aluminosilicate builder which are referenced as aluminosilicate ion exchange materials and sodium carbonate. The aluminosilicate ion exchange materials used herein as a detergent builder preferably have both a high calcium ion exchange capacity and a high exchange rate. Without intending to be limited by theory, it is believed that such high calcium ion exchange rate and capacity are a function of several interrelated factors which derive from the method by which the aluminosilicate ion exchange material is produced. In that regard, the aluminosilicate ion exchange materials used herein are preferably produced in accordance with Corkill et al, U.S. Pat. No. 4,605,509 (Procter and Gamble), the disclosure of which is incorporated herein by reference.
Preferably, the aluminosilicate ion exchange material is in xe2x80x9csodiumxe2x80x9d form since the potassium and hydrogen forms of the instant aluminosilicate do not exhibit as high of an exchange rate and capacity as provided by the sodium form. Additionally, the aluminosilicate ion exchange material preferably is in over dried form so as to facilitate production of crisp detergent agglomerates as described herein. The aluminosilicate ion exchange materials used herein preferably have particle size diameters which optimize their effectiveness as detergent builders. The term xe2x80x9cparticle size diameterxe2x80x9d as used herein represents the average particle size diameter of a given aluminosilicate ion exchange material as determined by conventional analytical techniques, such as microscopic determination and scanning electron microscope (SEM). The preferred particle size diameter of the aluminosilicate is from about 0.1 micron to about 10 microns, more preferably from about 0.5 microns to about 9 microns. Most preferably, the particle size diameter is from about 1 microns to about 8 microns.
Preferably, the aluminosilicate ion exchange material has the formula
Naz[(AlO2)z.(SiO2)y]xH2O
wherein z and y are integers of at least 6, the molar ratio of z to y is from about 1 to about 5 and x is from about 10 to about 264. More preferably, the aluminosilicate has the formula
Na12[(AlO2)12.(SiO2)12]xH2O
wherein x is from about 20 to about 30, preferably about 27. These preferred aluminosilicates are available commercially, for example under designations Zeolite A, Zeolite B and Zeolite X. Alternatively, naturally-occurring or synthetically derived aluminosilicate ion exchange materials suitable for use herein can be made as described in Krummel et al, U.S. Pat. No. 3,985,669, the disclosure of which is incorporated herein by reference.
The aluminosilicates used herein are further characterized by their ion exchange capacity which is at least about 200 mg equivalent of CaCO3 hardness/gram, calculated on an anhydrous basis, and which is preferably in a range from about 300 to 352 mg equivalent of CaCO3 hardness/gram. Additionally, the instant aluminosilicate ion exchange materials are still further characterized by their calcium ion exchange rate which is at least about 2 grains Ca++/gallon/minute/-gram/gallon, and more preferably in a range from about 2 grains Ca++/gallon/minute/-gram/gallon to about 6 grains Ca++/gallon/minute/-gram/gallon.
The starting dry detergent material in the present process can include additional detergent ingredients and/or, any number of additional ingredients can be incorporated in the detergent composition during subsequent steps of the present process. These adjunct ingredients include other detergency builders, bleaches, bleach activators, suds boosters or suds suppressers, anti-tarnish and anticorrosion agents, soil suspending agents, soil release agents, germicides, pH adjusting agents, non-builder alkalinity sources, chelating agents, smectite clays, enzymes, enzyme-stabilizing agents and perfume. See U.S. Pat. No. 3,936,537, issued Feb. 3, 1976 to Baskerville, Jr. et al., incorporated herein by reference.
In order to make the present invention more readily understood, reference is made to the following examples, which are intended to be illustrative only and not intended to be limiting in scope.

High density detergent-making process involving a moderate speed mixer/densifier


In the present capillary electrokinetic chromatograpy method, analytes are injected by electroosmotic flow directly from a sample matrix into a separation buffer containing an electrokinetic vector with an opposite mobility. Analytes can now be injected at the velocity of electroosmotic flow, but are retained at the interface of the sample matrix-co-ion and separation buffer micelle zones as analyte/micelle complexes. Manipulation of the injecting force and opposing stacking force allow greatly increased length or volume of injection. Concentrations of the micelle, methanol, and borate in the separation buffer were provided to increase maximum injection length of neutral analytes. Reducing the analyte velocity in the separation buffer without substantially decreasing the velocity of the analyte during injection from the sample vial allowed greatly extended sample plug injection lengths. It is further enabled to inject sample solvent volumes equivalent to about twenty times the effective capillary volume. Equations and algorithms describing the injection process and maximum injection lengths for this mode of stacking in electrokinetic capillary chromatography are introduced. Use of the present method provides for maximum electrokinetic stacking injection for a wide variety of analytes and separation systems.

In broad terms, analytical chemistry involves some combination of separation, identification, and quantitation of analytes of particular interest. To accomplish these goals, it is necessary to provide a sufficient concentration of the analytes at the detection point in the analytical device to register a signal at the detector that is distinguishable from background signal. With analyte concentrations below parts per million (ppm), many analytical detection systems are inadequate to detect the analyte.
Capillary electrophoresis (CE) is a high-resolution technique for separating charged analytes in liquid solutions using electric fields. The micron-scale radial dimensions of the capillary serve to dissipate Joule heating and control convection efficiently at high separation voltages, allowing for plate heights of micrometers or less. However, because of the small radial dimension of a capillary, it is difficult to detect short injected plug lengths of low-concentration analytes using standard optical detection set-ups (e.g., UV-VIS absorbance detection). Hence, the injection of large sample volumes (i.e., long sample plugs) has been necessary to improve the detection of analytes present at low concentration. Normally, the injected length of an analyte plug injected into some form of separation column, determines the minimum peak width at the detection point. As a result of the fact that separation columns are of a finite length, injection plug length is limited, in practical terms, to the millimeter range—beyond this, the high-resolution capabilities of capillary electrophoresis cannot be preserved. However, this problem has been circumvented by protocols that invoke mechanisms that narrow, or stack, much longer analyte zones into sample plugs. Stacking concentrates the analytes into smaller space, decreasing the length of an analyte zone and, thus, increasing the analyte concentration and its signal at the detector.
FIG. 8 shows an exemplary setup that can be used to practice electrophoresis. Electrophoresis unit 1 is interfaced with data collection/storage unit 14, which contains software/firmware/hardware for control of the instruments and data collection (e.g., processor, personal computer, display monitor and printer, or personal digital assistant (PDA) or the like. Separation channel 2 (shown here as a capillary) has an entrance (inlet) end 4, an exit (outlet) end 6, and a detection window 8. Separation channel 2 is flushed by high pressure or vacuum with three to five capillary volumes of buffer. The outlet reservoir 10 is filled with buffer and holds the exit end 6 of separation channel 2. Inlet reservoir 12 is also filled with buffer and holds the entrance end 4 of separation channel 2. Sample reservoir 11 contains sample for injecting into the separation channel 2. The high voltage power unit 16 has an anode 18 and a cathode 20. Outlet reservoir 10 also holds cathode 20, while inlet reservoir 12 also holds anode 18. An electric field is then applied by high voltage power unit 16 across separation channel 2 from anode 18 to cathode 20, which causes buffer in inlet reservoir 12 to travel through separation channel 2 and into outlet reservoir 10, for electrophoretic conditioning of separation channel 2. After separation, channel 2 has been electrophoretically conditioned, anode 18 and entrance end 4 of separation channel 2 are placed within sample reservoir 11. An electric field may be applied across separation channel 2 for electrokinetic injection (injection by electrophoresis instead of by pressure) of a sample plug into separation channel 2. The electric field is applied across separation channel 2 for a period of time sufficient to permit injection of a sample plug of desired length. Alternatively, the plug could be injected into separation channel 2 using a pressure technique known in the art.
Once an analytes zone is located at the detection window 8, radiation, for example from an ultraviolet (UV) light source 34, shines through on the detection window 8 and, therefore, through the analytes—the amount of light transmitted through the sample and window is detected by the detector 36 located on the opposite side of detector window 8 from UV source 34. The detector 36 is interfaced with a data collection/storage unit 14 to collect the separation data including the number of analytes zones to traverse the window as well as the relative amount of light that was incident on the detector (which translates to "concentration").
FIG. 9 is an illustrative setup used to practice electrophoresis. The electrophoretic unit 101 is a T-configuration cross-channel injection microchip. Separation Channel 102 has an entrance end 104, an exit end 106. Outlet reservoir 110 is filled with buffer and is connected to exit end 106 of separation channel 102. Inlet reservoir 112 is also filled with buffer and is connected to entrance end 104 of separation channel 112. Sample channel 140 has an entrance end 142 and an exit end 144. Sample reservoir 111 contains sample for injecting into separation channel 102 and is connected to entrance end 142 of sample channel 140. Waste reservoir 146 is filled with buffer and is connected to exit end 144 of sample channel 140. Sample channel 140 is configured to connect through and cross over separation channel 102 to form a 'T-configuration'. High voltage power unit 116 has an anode connected to inlet reservoir 104 and an anode connected to sample reservoir 111, and a cathode connected to outlet reservoir 110 and a cathode connected to waste reservoir 146. An electric field is applied across separation channel 102 for electrophoretic conditioning. The field is applied from anode connected to inlet reservoir 112 to cathode connected to outlet reservoir 106. For electrokinetic injection of a sample plug into separation channel 102 (not by pressure which is the current state-of-the-art), an electric field is applied from anode connected to sample reservoir 111 to cathode connected to outlet reservoir 106 for a defined period of time. An electric field is then applied across separation channel 102 causing separation and detection of the various analyte zones. The field is applied from anode connected to inlet reservoir 112 to cathode connected to outlet reservoir 106.
To separate neutral analytes by CE, it is necessary to provide an electrokinetic vector. The first example of this, micellar electrokinetic chromatography, utilized a charged micelle to impart mobility to neutral analytes. As a result of the successful use of other electrokinetic vectors that are not micellar in character, (e.g., charged cyclodextrins) electrokinetic chromatography (EKC) is a term that has been utilized to encompass the use of any electrokinetic vector for separation of neutral analytes. Recent techniques for stacking neutral analytes in EKC require pressure injections of sample matrixes. For instance, high-salt stacking and sweeping have been applied to afford sample plug lengths up to 60% of the effective capillary length (length from the injection end to the detection point). High-salt stacking utilizes discontinuous buffer conditions (the separation matrix co-ion is different from the sample matrix co-ion). The sample matrix co-ion (the ion with the same charge as the electrokinetic vector, e.g., chloride) must have a higher intrinsic electrophoretic mobility than the electrokinetic vector, and the sample co-ion must be present at a higher concentration in the sample matrix than that of the electrokinetic vector in the separation buffer.
Also, sweeping utilizes continuous sample matrix/separation buffer conditions, i.e., there are no mobility differences between the background electrolyte or buffer, between the sample matrix and the separation buffer.
In addition, pressure injections are typically low-velocity to diminish mixing at the sample matrix/separation buffer interface and to maintain reproducibility between analyses. While typical separations take as little as 60 seconds, the time necessary to introduce long sample plugs (e.g., 50% of the capillary length, ca. 50–2000 seconds) by low pressure can, in certain instances, exceed the analysis time by more than an order of magnitude.
Another drawback associated with large sample plug pressure injections is that the effective capillary length available for separation is reduced, having undesirable effects on the ability to resolve analytes. While longer capillaries might be used to overcome this problem, the 30 kV limit associated with most CE instrumentation does not allow for the same high fields (800–1000 volts/cm) typically needed for rapid, high-resolution analyses to be applied.
In addition, longer capillary lengths are not conducive with translating stacking methods from the traditional capillary format to the microchip format.
There is, therefore, a need in the art to inject large volume sample plugs (exceeding the length of the separation column) while still retaining a maximal effective capillary length for the separation mode. The electroosmotic flow can be used to inject neutral analytes in EKC without stacking, however, a concomitant stacking of neutral analytes during electrokinetic injection by electroosmotic flow is possible—this is described herein. Furthermore, the electrokinetic injection of high-salt sample matrixes by electroosmotic flow is provided, with the stacking of neutral analytes occurring simultaneously with the injection procedure, in both high-salt stacking and sweeping modes.

Method for orthogonal analyte stacking/injection systems in electrophoresis

University of Virginia Patent Foundation


Methods, compositions and kits are disclosed for obtaining directionally truncated polypeptides by inserting a transposon. Preferably the transposon comprises a selectable marker and an ori, and optionally a promoter, a ribosome binding site and a translation start codon, into a target sequence in vitro or in vivo. Amplification products, varying in length depending on the transposon insertion site, are obtained using one primer that anneals to the target sequence and a second primer that anneals to the transposon. Amplification products are ligated to circular dsDNA, transformed into host cells, and individual colonies, each containing a directionally truncated clone of the target sequence, are obtained by plating on medium for which the selectable marker encodes resistance. Directionally truncated polypeptides encoded by the target sequence are obtained in vivo by inducing an RNAP in the host cells that uses the promoter or, in vitro by cell-free transcription and translation.

I. Field of the Invention
The present invention relates generally to methods, compositions and kits for making unidirectionally or bidirectionally truncated polypeptides. The invention has broad applicability for research, industrial, and therapeutic uses, such as, but not limited to uses for engineering of proteins, including enzymes, identification of protein domains, changing protein functionality, epitope mapping, and for preparation of antigenic peptides for production of vaccines.
II. Description of Related Art
The introduction of deletions in nucleic acid sequences is a widely used method in molecular biology to study polypeptides encoded by the nucleic acid sequences.
Multiple procedures have been developed to generate deletions in nucleic acids, including procedures disclosed by Dunn et al. (U.S. Pat. No. 5,928,908; U.S. Pat. No. 5,968,768; and U.S. Pat. No. 6,248,569); Shen et al. (U.S. Pat. No. 5,356,773); Yohda et al. (DNA Research, 2: 175-181, 1995); Zhu and Marshall (BioTechniques, 18: 222-224, 1995); and Henikoff et al. (Gene, 28: 351-359, 1984 and U.S. Pat. No. 4,843,003). Other procedures for generating deletions have utilized variations of PCR (e.g., Pues et al., Nucleic Acids Res. 25: 1303-1304, 1997). All of the above are incorporated herein by reference in their entireties.
The current techniques for generating deletions in a target sequence are time-consuming and wasteful and what is needed are procedures to make deletions of nucleic acids that encode proteins that are less time-consuming and more efficient. What is further needed are procedures that allow the generation of deletions without the need to first clone the nucleic acid sequence of interest into a vector. Also, what is needed are methods to make large quantities of deletions in a random fashion, so that surprising and unexpected results can be obtained.
DNA transposons are mobile elements that can move from one position in a genome to another. In nature, transposons play roles in evolution as a result of their movements within and between genomes. Transposons are relatively simple genetic systems, consisting of some genetic sequence bounded by inverted terminal repeats and a transposase enzyme that acts to cut the transposon out of one source of DNA and paste it into another DNA sequence. Autonomous transposons carry the transposase gene inside the transposon whereas non-autonomous transposons require another source of transposase for their mobilization.
Multiple studies of transposition have been have been published (Devine et al., U.S. Pat. No. 5,677,170; Devine et al., U.S. Pat. Nos. 5,728,551 and 5,968,785; Hackett et al., International Patent Application No. WO 98/40510; Plasternak et al., International Patent Application No. WO 97/29202; Reznikoff et al., International Patent Application No. WO 98/10077; Craig, International Patent Application No. WO 98/37205; Strathman et al., Proc. Nat. Acad. Sci. USA 88: 1247-1250, 1991; Phadnis et al., Proc. Nat. Acad. Sci. USA 86: 5908-5912, 1989; Way et al., Gene 32: 269-279, 1984; Kleckner et al., Method. Enzymol. 204: 139-180, 1991; Lee et al., Proc. Nat. Acad. Sci. USA 84: 7876, 1987; Brown et al., Cell, 49: 347-356, 1987; Eichinger et al., Cell, 54: 955-966, 1988; Eichinger et al., Genes Dev., 4: 324-330, 1990; all of which are incorporated herein by reference in their entireties.
A number of studies have reported on deletions generated by transposons or the use of transposons to generate deletions for using in nucleic acid sequencing. Among these are articles by Ahmed (J. Mol. Biol., 178: 941-948, 1984); Hattori et al. (Nucleic Acids Res. 25: 1802-1808, 1997); Jilk et al. (J. Bacteriology, 175: 1264-1271, 1993); Krishnan et al. (Nucleic Acids Res. 23: 117-122, 1995); Morita et al., (DNA Research, 3: 431-433, 1996); Sugino et al. (U.S. Pat. No. 6,265,159 BI); Wang et al. (J. Bacteriology, 176: 6348-6354, 1990); and Wang et al. (Proc. Natl. Acad. Sci., 90: 7874-7878, 1993), all of which are incorporated herein by reference in their entireties.
Methods for using vectors with specially positioned and oriented transposon end sequences and a transposase were used for making unidirectional deletions in a target sequence cloned into the vector for a variety of purposes, as described by York et al. (Nucleic Acids Res. 26: 1927, 1998 and U.S. Pat. No. 5,948,622). These researchers also described how the methods could be used for making unidirectionally truncated polypeptides.
In U.S. Pat. No. 6,593,113, which is incorporated herein by reference in its entirety, Tenkanen et al. describe the use of a transposition reaction and a subsequent amplification reaction for providing templates for DNA sequencing. The inventors do not envision a method for making truncated polypeptides.
WO03/87370, incorporated herein by reference in its entirety, teaches a method for producing deletion derivatives of polypeptides by inserting transposons that contain translation stop signals into target nucleic acid sequences that have been cloned into vectors. The need to first clone a nucleic acid sequence of interest is time consuming and lacks efficiency.

Methods for obtaining directionally truncated polypeptides


The present invention provides a heat conducting slug having a multi-step structure, which is installed to an LED package to dissipate heat generated from a light emitting chip to the outside. The heat conducting slug includes a first slug, a second slug formed on the first slug, and a third slug formed on the second slug, wherein the light emitting chip is mounted to the third slug, and the second and third slugs respectively shaped to have edges are arranged to cross each other. In this configuration, heat generated from a light emitting chip follows a heat dissipation path, in which the heat is gathered at edges of one slug and dissipated therefrom and then gathered toward edges of another slug, arranged to cross the one slug. Accordingly, the entire heat dissipation path is not concentrated at a specific region but generally distributed widely, thereby improving a heat dissipation effect of the heat conducting slug.

1. Field of the Invention
The present invention relates to a light emitting diode (LED) package having an improved heat dissipation efficiency, and more particularly, to a heat conducting slug having a multi-step structure, wherein a slug structure of an LED package is configured into a multi-step structure so that heat generated from a light emitting chip is efficiently dissipated, and an LED package using the heat conducting slug.
2. Discussion of the Background
In recent years, an interest in lighting devices using an LED chip tends to increase. In order to use such an LED for lighting purpose, luminous power over several thousand lumens (where 1 lumen is a luminous flux emitted from a light source of one candela per a unit solid angle) is required in addition to improved quality of light emission. Such a high power light emission is in proportion to the input current, so that high current may give a required luminous power. However, if the input current is increased, a large amount of heat is generated accordingly.
A large amount of heat generated from the light emitting chip has fatal influence on the life span of the light emitting chip. In order to solve the problem, an LED package having a heat dissipation member such as a slug is manufactured.
Conventionally, in order to improve a heat dissipation effect of a slug, there has been an attempt to change the material and size of the slug. However, there is a limit in changing the material and size of the slug, and thus, other studies for enhancing a heat dissipation effect of a slug are needed.
Meanwhile, among conventional LED packages, there is an LED package having a molding member formed by casting molding, wherein a molding member is formed by mounting a slug in a housing, bringing an additional mold into close contact therewith while a light emitting chip is mounted in the slug, and then injecting a liquid resin into the mold.
However, since the liquid resin is injected at high pressure into the mold in the conventional technique, the mold may not be in close contact with the housing but be separated due to the pressure in the mold. In a case where the mold is separated from the housing when the liquid resin is injected into the mold, the mold cannot be in close contact with the housing again, thereby making it impossible to form a molding member, which causes product failures. In addition, even though the mold is in close contact with the housing again, the liquid resin in the mold may leak out through a gap generated by the separation between the mold and the housing, thereby resulting in product failures.
In addition, in a case where a slug is mounted after the housing is formed, the slug is separated from the LED package, which may cause device failures. Such device failures cause disconnection of wire, which makes it impossible to use the LED package again. Thus, it is required to assemble a slug and a housing such that the slug is not separated from the LED package.

Heat conducting slug having multi-step structure and light emitting diode package using the same


In order to stabilise the colour of pasta containing ingredients of marked coloration such as spinach, tomatoes and the like, the pasta is treated with saturated steam at 75.degree. to 80.degree. C. and is then dried at temperatures below 60.degree. C. until a moisture content of 11% is reached.

In its general aspects, the present invention relates to a method of drying pasta.
In particular, this invention relates to a process of drying pasta which contains ingredients of marked coloration such as spinach, tomatoes, etc. which impart characteristic colour and flavour to it.
Even more particularly, the invention relates to a method of drying pasta of the aforesaid type which is intended to stabilise the colour of the dry pasta.
It is well known that dry pasta to which ingredients have been added to impart to it particular characteristic features of flavour and colour is subject to rapid deterioration which, according to the ingredients used in the pasta, will already be apparent 15-30 days after production and will increase progressively in a significant manner so that after some time the pasta assumes an appearance and a flavour which are far removed from the original flavour and appearance.
In fact, it is readily possible to establish that in pasta which is kept in the dark, for example in opaque containers, the colour of the pasta becomes progressively more brown. Thus, for example, tagliatelle with a spinach filler and packed in opaque containers, will lose its original green colour and become brown.
In other cases, in pasta which is kept in packages which are transparent to the light, the original colour progressively darkens and tends towards light grey. For example, spinach-filled tagliatelle turns from the original green to a yellowish colour and finally to grey.
Although less obvious than the deterioration in the colour, the flavour of these pastas to which ingredients of the type in question have been added is also subject to a progressive deterioration which may reach a point where the actual product is spoiled.
The problem which is at the root of this invention is that of obviating the aforementioned disadvantages and making available a treatment to stabilise the colour of the coloured dry pastas, which can be easily integrated into a general process for the production of dry pasta, employing the same apparatus as are normally used in such processes.

Method of drying pasta containing ingredients of marked coloration

Barilla G. eR. F.lli - Societa Per Azioni


Apparatus and method for detecting leaks within underground or aboveground tanks and their associated piping whether the tank and/or piping is partially filled or empty. The apparatus is partially insulated to minimize temperature effects when injecting a test gas into the tank to be tested. The tank is pressurized to a fill pressure by injecting (bubbling) the test gas through any liquid in the tank. Once stabilized the pressure is reduced to a test pressure while the gas injection continues. The flow rate of gas into the tank is monitored by a flow meter able to measure small flows while the pressure is held constant by a pressure regulator having a high accuracy and the temperature of the ullage is monitored. A tight or leaking tank is determined by evaluating the flow rate of constant pressure against reference criteria which when met identify a tight tank and when not met identify a leaking tank under EPA guidelines. Temperature, deflection, and other effects on leak rate detection are compensated for by prescribing waiting periods, filling times, and multiple and repeat threshold exceedance criteria. Flow rate, temperature and pressure can be reached manually or fed to a suitable computer or chart recorders for permanent records and/or automated testing.

Tanks are used to store a wide variety of fluids and gasses, especially petroleum, as well as other liquids containing or consisting of various chemicals, and also for storing water. Many of these tanks and/or piping connected to the tanks when tested have been found to have active leaks or the potential for leaks. Some current estimates indicate that from 1% to 45%, or even more of such tanks have leaks. Leaking tanks and leaking tank piping can contaminate the ground water and cause other types of environmental pollution which become health and safety hazards.
In recent years leak detection methods have been developed to test underground storage tanks for leaks. In December 1988, the United States Environmental Protection Agency (U.S. EPA) adopted regulations requiring that such leak detection methods for underground storage tanks meet certain leak detection criteria, i.e. the ability to detect a 0.1 gph (gallon per hour) leak with a probability of detection of 95% and a false alarm rate of 5%. No known leak detection method has been able to meet this U.S. EPA leak detection requirement for (1) an empty tank and associated piping or (2) tank and piping together in which the tank is partially filled with liquid to less than 70% of its volume.
Several attempts have been made to solve this problem (i.e. U.S. Pat. Nos. 4,568,925; 4,353,245; 3,918,291; 3,893,332; 4,791,814; and 4,852,054). Each of these prior art devices and/or methods have certain disadvantages which make them unacceptable for detecting leakage in underground storage tanks of the low pressure variety. The testing methods in several of the cited patents require a precise measurement of the liquid level in the tank. These methods are unable to detect tank leaks where the leak is located above the liquid level in the tank or in its associated piping. Other methods require that the tank be pressurized to a very high pressure (i.e. 4000 psi for submarines, in order to determine the acceptability of leakage). Still other methods require that a nitrogen or helium detector be employed in such a way as to detect leakage of such gasses which are used to pressurize the tank. These methods require that the tank leakage flows be directed to the gas leak detector or that detector access to all parts of the tank and piping be provided so that the leak detector apparatus can sense low gas concentrations (indicating small leaks) as required by the EPA standards.
Prior art methods have been somewhat successful for detecting leaks in generally full tanks and tanks which are able to sustain high internal pressures. However, prior art methods have not been successful in meeting the EPA guidelines for empty or partially filled generally low pressure tanks and associated piping. The test results from prior art methods and devices are influenced by many of the effects associated with the underground and aboveground storage tanks such as: tank deflection, temperature changes, ground water, tank structure, ullage space, product level, and product type. The interaction of these effects can and does cause unacceptably inconsistent results from the prior art test devices and methods.

Method and apparatus for detecting leaks in the ullage of a liquid storage tank