A process for the manufacture of a coating or doctoring blade comprising a band of steel or other form-stable material and a wear-resistant polymer coating applied on said band along a longitudinal edge section thereof subjected to wear, said process comprising the following steps: (a) providing continuous relative movement between said band and an application and treatment station; (b) continuously applying at said station a fast-curing polymer composition along said edge section; (c) allowing the applied composition to spread out so as to reach the very extreme of said edge section and then to cure to form an elastic and tacky-free coating; and, optionally (d) post-curing the coating at an increased temperature; as an alternative to such process there can be used a blade of double width compared to said first band and continuously supplying a fast-curing composition along a longitudinal central section of double width compared to said edge section and longitudinally cutting said second band along the middle of the coated central section thereof to form two tip-coated blades; and a coating or doctoring blade prepared by such process.

The present invention relates to processes for the manufacture of coating or doctoring blades comprising a band of steel or other form-stable material and a wear-resistant coating applied onto said band along a longitudinal edge section thereof subject to wear.
Coating or doctoring blades tipped with rubbery or soft material are presently prepared only by moulding in a closed mould in which a band of steel or other form-stable material is placed and constitutes substrate for the coating. A liquid mix of components is injected at the lower end of a preheated mould until it appears at the opposite upper end. Care has to be taken to prevent introduction of air bubbles in the liquid material and no leakage from the mould must occur. A demoulding agent, generally based on silicones, is applied on the mould surfaces to prevent sticking of the cured material. Once filled, the mould is introduced into a circulated air oven at 80-110xc2x0 C. until curing has taken place so that the blades can be demoulded. This takes generally 45 to 180 minutes. After demoulding the blades are post-cured at 80-110xc2x0 C. for 12-24 hours.
This batch process is associated with several disadvantages, among which the main drawbacks are:
the process encounters low productivity;
each new blade geometry and blade length requires a new mould;
the mould manufacturing costs are high, especially for large moulds with complex profiles;
the larger the mould, the larger the oven necessary to preheat the mould and to cure the rubbery or soft material, and the higher the pressure necessary to fill the mould;
there are limitations in blade length because of difficulties in filling the mould without defects occurring, the need for longer pot-lives and lower viscosities, increasing mould weight, time to open, close and clean the mould etc.
For these and other reasons it is desirable to develop a simple and economic continuous process to produce such blades without limitations to length and geometry.
One object of the invention is to provide a continuous process for the manufacture of coating or doctoring blades provided with a wear-resistant soft or rubbery coating.
Another object of the invention is to provide such a process which will impart no limitations to blade length and geometry of the coated blade.
Still another object of the invention is to provide a continuous process which is commercially competitive and flexible to meet consumers specifications.
For these and other objects which will be clear from the following disclosure the invention provides a continuous process for the manufacture of coating or doctoring blades comprising a band of steel or other form-stable material and a wear-resistant polymer coating applied on said band along a longitudinal edge section thereof subjected to wear. The process involves the following steps:
a) providing continuous relative movement between said band and an application and treatment station;
b) continuously applying at said station a fast-curing polymer composition along said edge section;
c) allowing the applied composition to spread out so as to reach the very extreme of said edge section and then to cure to form an elastic and tacky-free coating; and, optionally
d) post-curing the coating at an increased temperature.
According to an alternative embodiment of such continuous process the following steps are involved:
a) providing continuous relative movement between a second band of double width compared to said first band and an application and treatment station;
b) continuously supplying at said station a fast-curing composition along a longitudinal central section of double width compared to said edge section;
c) allowing the applied composition to spread out to the desired width and then to cure to form an elastic and tacky-free coating and, optionally, post-curing the coating at an increased temperature; and
d) longitudinally cutting said second band along the middle of the coated central section thereof to form two tip-coated blades.
In the process according to the invention it is preferred to introduce before application step b) above a roughening step for said edge or central section to improve the adhesion of the coating.
It is also preferred for further improving the adhesion of the coating to apply a primer before application step b) above.
According to a preferred embodiment of the invention the fast-curing polymer composition has a pot-life of about 5 to about 30 sec.
Among preferred fast-curing polymers there may be mentioned those selected from polyurethanes, styrene-butadien polymers, polyolefins, nitrile rubbers, natural rubbers, polyacrylates, polychloroprene, thermoplastic elstomers, and polysiloxanes. It is particularly preferred to use as a polymer a polyurethane.
A suitable fast-curing polymer composition is a 3-component liquid polyurethane composition containing a prepolymer, a polyol and a chain extender. Such composition is continuously mixed with a catalyst solution, whereafter the mixture is applied onto the band to be coated.
The coating width is preferably from about 5 to about 40 mm and a preferred thickness is from about 1 to about 3 mm.
After curing of the coating it is preferred to subject the coating to a grinding operation to obtain the desired profile or geometry.

Process for the manufacture of soft tipped blades


Disclosed herein is a method for producing potassium fluorotantalate crystals, comprising heating, to 60xc2x0 C. or higher, a starting solution prepared by adding hydrofluoric acid and hydrochloric acid, and, if necessary, water to a highly pure tantalum solution, adding potassium chloride to this starting solution, and cooling the mixture to 40xc2x0 C. or lower at a cooling rate of less than 15xc2x0 C./h to precipitate potassium fluorotantalate crystals, wherein the concentration of the hydrofluoric acid in the starting solution is not more than 20% by weight. By this method, highly pure, large-sized potassium fluorotantalate crystals can successfully be obtained in high yield. Moreover, disadvantages to equipment and operation in the prior art can be overcome to a significant extent with this method.

1. Field of the Invention
The present invention relates to a method for producing potassium fluorotantalate crystals by which highly pure, large-sized potassium fluorotantalate crystals can be obtained in high yield and which is almost free from disadvantages to equipment and operation in the prior art; and to potassium fluorotantalate crystals produced by this method.
2. Background Art
Potassium fluorotantalate is used for the production of tantalum powder; it is particularly important as raw material for tantalum condensers. A general process of producing potassium fluorotantalate in the prior art is shown in FIG. 3. As shown in this figure, raw material such as tantalite ore or tantalum condenser scrap is firstly crushed, and dissolved by adding thereto hydrofluoric acid. Thereafter, sulfuric acid is added to this solution to adjust its concentration, and the solution adjusted is filtered through a filter press to obtain a clean solution, which is then subjected to solvent extraction. The solution is brought into contact with an organic solvent MIBK to extract tantalum and niobium, and the extract is back-extracted with dilute sulfuric acid to remove niobium. The remaining organic phase is then back-extracted with water, thereby obtaining a purified tantalum solution.
The tantalum solution thus obtained is subjected to the following two steps: a first step in which an aqueous solution containing K derived from KF, KCl, K2CO3, KOH or the like is added to the tantalum solution to precipitate crude potassium fluorotantalate crystals, and the crude crystals are separated by filtration; and a second step in which the crude potassium fluorotantalate crystals are dissolved in a hot dilute hydrofluoric acid solution, and the solution is then cooled to recrystallize highly pure potassium fluorotantalate crystals. Thus, the production of highly pure potassium fluorotantalate crystals usually involves two crystallization steps in the prior art.
However, when a dilute hydrofluoric acid solution is used in the recrystallization step as in the above-described conventional process, the resulting crystals tend to be not satisfactorily large in size. Moreover, the solubility of potassium fluorotantalate in a dilute hydrofluoric acid solution is low, so that there can be obtained crystals only in a decreased amount per unit operation.
Japanese Laid-Open Patent Publication No. 32897/1974 discloses a method for purifying crude potassium fluorotantalate crystals by recrystallization, in which potassium fluorotantalate is crystallized not from a dilute hydrofluoric acid solution but from a hydrofluoric acid solution having a high concentration of 20 to 50% by weight. Although coarse crystals can be obtained by this method, a large amount of potassium fluorotantalate remains in the hydrofluoric acid solution after the crystallization by cooling has been completed, so that potassium fluorotantalate crystals cannot be obtained in sufficiently high yield. In addition, since a hydrofluoric acid solution, which is extremely reactive, is used at a high concentration, the equipment used is readily eroded, and the handling of the solution requires great care. This method thus has great disadvantages to equipment and operation.
The present invention has been accomplished under the above-described circumstances. An object of the present invention is therefore to provide a method for producing potassium fluorotantalate crystals by which highly pure, large-sized potassium fluorotantalate crystals can be obtained in high yield and which is almost free from disadvantages to equipment and operation in the prior art. Another object of the present invention is to provide potassium fluorotantalate crystals that can be obtained by this method.
The above object can be attained by a first embodiment of the present invention, that is, a method for producing potassium fluorotantalate crystals, comprising heating, to 60xc2x0 C. or higher, a starting solution prepared by adding hydrofluoric acid and hydrochloric acid, and, if necessary, water, to a highly pure tantalum solution, adding potassium chloride to this starting solution, and cooling the mixture to 40xc2x0 C. or lower at a cooling rate of less than 15xc2x0 C./h to precipitate potassium fluorotantalate crystals, wherein the concentration of the hydrofluoric acid in the starting solution is not more than 20% by weight.
The above object can also be attained by a second embodiment of the present invention, that is, a method for producing potassium fluorotantalate crystals, comprising (a) a first step in which a potassium-containing electrolyte is added to a starting solution containing tantalum to precipitate crude potassium fluorotantalate crystals, and the crude crystals are separated by filtration, and (b) a second step in which, after heating, to 60xc2x0 C. or higher, a recrystallization solvent which is an aqueous solution containing hydrochloric acid and hydrofluoric acid, the crude potassium fluorotantalate crystals are dissolved in this recrystallization solvent, and the solution is then cooled to 40xc2x0 C. or lower at a cooling rate of less than 15xc2x0 C./h to precipitate potassium fluorotantalate crystals.
The potassium fluorotantalate crystals produced by the method of the present invention have (i) a content of the impurities Fe, Ni, Cr, Mn and Cu, calculated from the total amount of the respective metallic elements, of 50 ppm by weight or less, or (ii) a content of the impurities Nb, Fe, Ni, Cr, Ca, Mg, Mn, Cu, Si, W, Al, Ti, Mo, Sn, Sb and S, calculated from the total amount of the respective metallic elements, of 100 ppm by weight or less. Further, the potassium fluorotantalate crystals of the invention contain 40% by weight or more of crystals whose sizes are 0.5 mm or more as determined by sieve analysis.

Method for producing fluorinated potassium tantalate crystal


A method and system are disclosed for a high current electrical switch. The switch may be suitable for switching, rectifying or blocking direct current in the range of one to a thousand amperes per module or assembly. It does so with such high efficiency that it produces relatively insignificant heat; such that it requires little or no cooling by convection or radiation. The relatively low heat that is generated in the process is conducted away quite effectively by the electric cables connected to the device.

1. Field of the Invention
The present invention relates in general to a high current electrical switch and a method of making it. It more particularly relates to such a high current electrical switch and method that has little or no need for a heat sink for many applications.
2. Background Art
The information contained in this section relates to the background of the art of the present invention without any admission as to whether or not such background art legally constitutes prior art.
Generally, the applications requiring direct current in the range of fifty to five hundred amperes will be found in systems operating in the voltage range of ten to a hundred volts. This window of electric power is found on board cars, trucks, boats, airplanes, recreational vehicles, telecom systems, photovoltaic systems wind power systems, oceanographic buoys, etc.
In recent years, MOSFET switches have been popular in computer systems, combining redundant power systems and/or batteries with a computing system such as a server, memory, and/or network. The limiting factor in most applications has been the resistance in the device from the drain to the source when the device is on, or the Rds(on) factor. This factor has been steadily reduced over the recent years by MOSFET manufacturers from sub-ohms to milli-ohms. Currently, devices with voltage ratings of 30 to 50 volts are available with an Rds(on) as low as 1.5 to 20 milli-ohms. As this parameter has asymptotically approached the one milli-ohm level, the package resistance (leadframe, wire bonds, etc.) limits much greater improvement. In the application of these high conductivity devices, the external resistances begin to swamp the improvement achieved in the MOSFET. The Rds(on) increases significantly (about a percent per degree Celsius) as the device temperature rises while conducting high currents.
To dissipate this temperature increase, the MOSFETs are placed on large costly heat sinks to carry away the heat produced as a result of the voltage drop. If these heat sinks are inadequate to avoid excessive heating of the MOSFETs, the MOSFETs may be destroyed. The common practice is to decrease the resistance between the MOSFET and its source and load as much as possible by increasing pad sizes, trace widths, trace thickness, and wire gauge, while decreasing trace lengths, wire lengths, and connector resistance within the limits imposed by the heat sink system.

High current electrical switch and method


Provided are gas processing facilities for the separation of components in a gas stream and methods of using the same. The facility includes one or more co-current contactors. Each contactor includes a mass transfer vessel having a mixing section. The mixing section receives a gas stream and a liquid contacting stream. The mixing section mixes theses two streams and releases a two-phase flow. Each contactor also includes a separator that receives the two-phase fluid stream from the mass transfer vessel in-line, and then separates a vapor phase from a liquid phase. The separator has a gas-phase outlet configured to release the vapor phase as a treated gas stream, and a liquid-phase outlet configured to release the liquid phase as a loaded treating solution. The contactors may be used to remove water or other contaminant from a natural gas stream or other gas stream.

This section is intended to introduce various aspects of the art, which may be associated with exemplary embodiments of the present disclosure. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present disclosure. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of prior art.

In-line device for gas-liquid contacting, and gas processing facility employing co-current contactors


A method is provided by the invention for making a security document comprising a thermoplastic substrate with a UV light cured printed image that is less likely to result in splitting of the ink of the UV light cured printed image during the lamination step of forming the thermoplastic substrate. The UV light cured image is applied to an interior thermoplastic layer surface of a stack of thermoplastic layers configured to form a thermoplastic substrate upon lamination of the stack and comprises numerous small sub-portions having small gaps between them sufficient to permit relative movement of individual sub-portions during lamination, the thermoplastic layer(s) from the ultraviolet light cured image to an exterior surface of the stack being sufficiently see-through that the image is visible upon viewing the security document. Alternatively, or additionally, the image is applied to an interior surface of an outermost thermoplastic layer of the stack adjacent an intermediate thermoplastic layer of the stack wherein the outermost thermoplastic layer has a higher melting point than the melting point of at least the adjacent intermediate thermoplastic layer.

Security documents such as identification cards and data pages may include one or more images or elements formed by printing or applying a UV light curable ink for security purposes. For example, a security document in the form of an identification card, a driver's license or personal identification sheet of a passport may be made of a thermoplastic substrate and may bear an image comprising a secure design feature that is printed onto the thermoplastic substrate using a UV light curable ink, where the ink film thickness of the cured ink is in the range of 5 to 12 microns thick. It is also known in the field of security document printing that screen printing produces a significantly thicker layer of ink than does, for example, lithography, type and offset printing and a thicker layer of ink in thermoplastic layers is more likely to result in ink splitting upon lamination of thermoplastic layers to form the security document.
To prevent or reduce security violations by tampering with such printed images they may be embedded within the thermoplastic substrate rather than apply them to a surface that is readily accessible to a tamperer. The thermoplastic substrate forming a security document is made from a stack of multiple layers of polymer, polycarbonate or other thermoplastic material which are laminated together to form a unitary substrate for a security document. To embed a UV light cured image within the security document the image is printed onto a surface of a stack layer using a UV light curable ink and the ink is cured prior to lamination of the multiple layers of the stack. To permit visibility of the image upon viewing the security document the thermoplastic layers located from the image to an outermost thermoplastic layer are clear or transparent (i.e. sufficiently see-through that the image is visible upon viewing the security document). Typically the thermoplastic substrate comprises a white inner core layer sandwiched between multiple clear or transparent layers and the image in applied to a surface of one such clear or transparent layer. However, the process of laminating (i.e. bonding together) the thermoplastic layers causes the layers to soften and reform under high temperature and pressure and because the UV light cured printed matter is relatively inelastic the lamination process may be damaging to the UV light cured image when a relatively thick layer of ink is applied by screen printing, and cause undesirable ink splitting (i.e. cracks) to form in the image.
Therefore, it is desirable to provide means for reducing the ink splitting of such embedded UV light cured images.

Method for making a security document comprising a thermoplastic substrate and UV-cured image and security document formed thereby


The storage system includes a first auxiliary storage device, a second auxiliary storage device, and a main storage device, and also includes a data management unit which stores and keeps, in the main storage device, index data based on feature data by referring to the feature data of storage target data stored in the first auxiliary storage device, and if the index data stored and kept in the main storage device reaches a preset amount, stores and keeps, in the second auxiliary storage device, the index data stored and kept in the main storage device, and deletes the index data stored and kept in the second auxiliary storage device from the main storage device.

Over the last few years, data deduplication has become one of the most widely researched topics in the field of storage systems. It enables significant savings as the required storage space can be reduced up to 20 times, especially for backup usage. In addition to capacity optimization, deduplication may also optimize write bandwidth. If a system provides inline deduplication (performed during writing data) and verifies equality of chunks by comparing their hashes only, the data of duplicated chunks do not need to be stored on disk or even transmitted through network. However, providing an effective way to identify duplicates is not simple.
Consider a sample single-node disk-based storage system with reliable, inline deduplication. We assume a 2u storage node with 12 1 TB disks for a total of 12 TB disk space per node. Deduplication is done on chunk level by comparing hashes of their content. Related work indicated a chunk size of 8 kB as a reasonable choice. To provide deduplication with this chunk size, we need a dictionary for 1.5 billion entries. Keeping only hashes for them will consume 30 GB for SHA-1 or 50 GB for SHA-256, and will not fit into RAM of a reasonable size.
Current systems implement the dictionary as a disk-resident hash table. However, hashes of data chunks are uniformly distributed and there is no locality while accessing them. This makes straight caching ineffective and causes random reads from disks during lookup. NPL 1 and 2 suggest a combination of two optimization techniques.
1. To avoid disk access during lookup of chunks not present in the system, all hashes are summarized in an in-memory bloom filter. This speeds up negative answers.
2. Prefetch assumes that the order of writing duplicates will be the same as the order of writing original chunks. Hashes are additionally kept in special files which reflect the order they were initially written. This speeds up positive answers, but only if the order is preserved.

Storage system, computer-readable medium, and data management method having a duplicate storage elimination function


A method for operating an internal combustion engine which has a number of cylinders and which comprises a fuel system and a fresh air system, whereby fuel is fed in a fuel mass flow via a fuel supply line of the fuel system to the cylinders at a prescribable air-fuel ratio directly by means of the injectors, and fresh air is fed in a fresh air mass flow via a fresh air system, whereby the fuel system comprises a tank venting system with a tank venting line that has a tank venting valve and that, via the interconnected tank venting valve, is connected to at least one line section of the fresh air system via at least one feed point, thereby forming at least one venting path, whereby, owing to a pressure which prevails at the at least one feed point and which is negative relative to the tank venting line and dependent on the load point, the fuel tank of the tank venting system is vented via the at least one venting path, a venting process in which a purging air mass flow containing fuel is removed from the tank venting system and fed to the cylinders as a portion of the fresh air mass flow, so that a total fuel mass flow is fed into the cylinders directly by means of the injectors of the fuel system as well as indirectly via the fresh air mass flow. It is provided that the direct feed of fuel by means of the injector of at least one of the cylinders is blocked, as a result of which a purging air mass flow comprising the fuel volume equivalent that is now absent due to the blocking of the at least one cylinder can advantageously be removed from the tank venting line, while maintaining the prescribed air-fuel ratio via the at least one venting path at the at least one feed point, and this purging air mass flow can be fed as a portion of the fresh air mass flow to the cylinder(s) that is/are still being supplied with fuel.

The invention relates to a method for operating an internal combustion engine which has a number of cylinders and which comprises a fuel system and a fresh air system, whereby fuel is fed in a fuel mass flow via a fuel supply line of the fuel system to the cylinders at a prescribable air-fuel ratio directly by means of the injectors, and fresh air is fed in a fresh air mass flow via a fresh air system, whereby the fuel system comprises a tank venting system with a tank venting line that has a tank venting valve and that, via the interconnected tank venting valve, is connected to at least one line section of the fresh air system via at least one feed point, thereby forming at least one venting path.
German patent application DE 10 2008 042 638 A1 discloses a method for operating an internal combustion engine, whereby a crankcase of the internal combustion engine has a venting system in the intake system of the internal combustion engine. When fuel is outgassed from engine oil that is present in the crankcase, the operating point of the internal combustion engine is changed so as not to fall below a prescribable air-fuel ratio. Therefore, a crankcase venting system is being put forward with which gases are conveyed from the crankcase into the intake pipe and thus into the intake system of the internal combustion engine. In this context, it is provided, for example, to select an operating point for the air-fuel ratio—especially the rich-running limit—that has a fuel consumption that is as high as possible. The outgassing of fuel can be ascertained by monitoring and measuring the lambda value control since it can be noted that the fuel-air mixture becomes richer during the outgassing. In summary, it is provided that the load point of the internal combustion engine should be raised in order to allow a higher purging rate of fuel gases, whereby a minimum injection time is explicitly cited as the existing limit of the fuel mass flow.
European patent application EP 2 530 262 A1 discloses a control unit for an internal combustion engine in which a fuel gas is returned to the intake system. In the associated method, NOx is measured and then returned to the intake system parallel to the fuel gas. In this process, the lambda value control serves to evaluate and regulate the mass flows.
U.S. Pat. No. 5,746,187 A describes a tank venting system. A method is disclosed that controls the mass flow rate of the tank venting volumetric flow. In this process, the lambda value control likewise serves to monitor the purging quantity, whereby the injected quantity or the actuation angle of the tank venting valve is appropriately adjusted.
Before the backdrop of the state of the art, the objective of the invention is to offer a solution that allows the purging air mass flow of the tank venting system to be increased, whereby, if at all possible, no additional components are needed that would have to be additionally integrated into the tank venting system of a fuel system.

Method for increasing the quantity of purging air in the tank venting system by completely blocking the injection of at least one cylinder


Provided is an ion generating device for an air-conditioner duct, which can be easily attached to the inside of an existing air conditioner duct and can ensure a desired ion generation quantity. The ion generating elements of the sub-units (3, 4, 5) of the ion generating device are connected to the drive circuit of the ion generating device main unit (2), and are driven by the drive circuit.

The recent demand for energy saving has been tending to increase the number of highly airtight, highly insulated houses, contributing to the increase in demand for air conditioning duct unit for use in such highly airtight, highly insulated houses. Also, hotels and office buildings have conventionally been provided with a central air conditioning system where each room is air-conditioned with air that is conditioned by an air conditioner and supplied through an air conditioning duct extending from the air conditioner to each room. In such an air conditioning system using an air conditioning duct unit or an air conditioning duct, an air-conditioning-duct outlet port is formed in a wall or the ceiling of a room, and conditioned air is introduced into the room through the outlet port.
In one example of such an air conditioning system which has been proposed, there is provided, inside an air conditioning duct, an ion generating device for generating negative ions which are said to have a relaxing effect on human mind and body, such that negative ions generated by the ion generating device are supplied to a room (see Patent Literature 1).


Disclosed herein are a vacuum cleaner including: a base including a suction opening; a main frame including a dust collecting apparatus configured to remove dust from air sucked through the suction opening; and a wheel assembly including a forward wheel and a reverse wheel, and rotatably coupled with the base, wherein when the main frame slides with respect to the base, any one of the forward wheel and the reverse wheel contacts a floor. Therefore, the vacuum cleaner may understand a user's intention without adding a senor and a control circuit, and travel actively according to the user's intention.

A vacuum cleaner is a home appliance including a fan motor to generate a suction force for sucking air from the floor to be cleaned, and a dust collecting apparatus to remove dust from the sucked air to clean the floor. There are various kinds of vacuum cleaners including a canister type, an upright type, a hand type, and a robot type.
An upright type vacuum cleaner includes a main frame having a handle and a dust collecting apparatus, and a base coupled with the main frame and having a suction opening, a brush, and one or more wheels. A user grips the handle of the main frame to clean the floor.
However, many users experience difficulties in operating the upright type vacuum cleaner due to its strong suction force and heavy weight. For this reason, some upright type vacuum cleaners include a driver for driving wheels such that the wheels can travel actively.
However, typical drivers could not accurately identify a user's intention, that is, a direction in which a user intends to clean, which caused cases in which the user is pulled by the vacuum cleaner. In order for a vacuum cleaner to accurately identify a user's intention, the vacuum cleaner needs various sensors and control circuits additionally.


The present application describes a method for improving user experience with filtering information. A free text entry is received on a user interface of a computer. A navigation key entry is also received on the user interface. Next, it is determined whether the free text entry fulfills criteria for a field input. Further, information is filtered based upon the fulfilled field criteria and the received navigation key entry. The application also is directed to a system for improving user experience on an electronic device.

1. Field of the Disclosure
The present application generally relates to systems, methods and applications for improving user experience with data retrieval. More specifically, the present application relates to methods, systems and application for controlling the display of data.
2. Related Art
The ability for a system or processor to deliver relevant search results to a query in an efficient manner is paramount in the twenty-first century. With users having increasingly less time available to structure focused searches, systems and processors have strived to improve their own architecture to locate relevant information requested or anticipated by a user. While the quality of the results may have improved, there have been significant reductions in efficiency.
Natural language text entry is used in many of today's search engines and recognized by systems and processors. Generally, a user freely types his or her query in a search box. The search engine attempts to understand the verbs, phrases and clauses to build a collection of results. Under the current available design architecture, challenges still exist for the system or processor to understand and recognize wide varieties of ambiguous input.
Other search engines employ keyword-based entry to search and retrieve information. That is, the system or processor may search a database for terms provided by the user. While keyword searching may be useful when the user is fairly confident with his or her search strategy the accuracy of the results may be compromised if one or more terms is not proper or not commonly used in the art.
What is needed in the art is a system, method and software application which improves efficiency with searching databases without compromising on the quality of the search hits.
What is also needed in the art is a system, method and software application that is easy to use and obtains relevant data with little time by the user to create a focused search.
What is further needed in the art is a system, method and software application that is user customizable.

Suggestive input systems, methods and applications for data rule creation


A method for testing an emergency lighting product connected to a network includes creating, at a network control device, a first test schedule for causing the emergency lighting product to perform a test, where the test is scheduled to be performed by the emergency lighting product based on a signal received from the network control device after a first time period. The method further includes creating, at the emergency lighting product, a second test schedule for causing the emergency lighting product to perform the test after a second time period, where the second time period is longer than the first time period and begins at the same time as the first time period, and determining, by the emergency lighting product after the second time period, that the signal has not been received from the network control device, and performing, by the emergency lighting product, the test.

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Safety standards, such as those defined by Underwriters Laboratories (UL) or the National Fire Protection Association (NFPA), may specify testing requirements for emergency products. Emergency products may include egress lighting fixtures, emergency lighting fixtures, battery backed-up room lighting, exit signs, combination exit sign/emergency lighting units, etc. For emergency lighting products, the testing requirements may include a monthly test to verify emergency operation and an annual test to verify that the fixture has sufficient backup power to operate in an emergency mode for a predefined time period. The duration of the monthly test may be on the order of several minutes and may be run once a month. The duration of the annual test may be longer, on the order of 90 minutes, and may be run once a year.
Individual emergency lighting products may be connected via a network. In some networks, there is a gateway that communicates with the emergency lighting products and manages the testing of the emergency lighting products. The gateway may send a message to an emergency lighting product instructing the unit to conduct the appropriate test and to respond with the results of the test. A failure at the gateway may result in the test not being run as required.

Connected life safety emergency lighting scheduler


A splatter protector including a hollow body having oppositely-directed first and second end portions. Each of the end portions may define a respective substantially circular end opening having an annular lip along the circumference thereof for engaging with upper edges of cooking vessels for mounting the splatter protector thereon, wherein the diameter of the end opening defined by the first end portion is greater than the diameter of the end opening defined by the second end portion. A kit including the splatter protector and a lid for covering at least one of the respective end openings defined by the first and second end portions of the splatter protector.

Splatter protectors are often used to reduce or eliminate splatter in a cooking area that can occur when cooking food. A number of such splatter protectors work only with a cooking vessel of a particular size. In the case of a kitchen that has cooking vessels of various sizes, a different splatter protector may be required for each cooking vessel. This can result in a kitchen cluttered with splatter protectors.
In addition, some splatter protectors sit in cooking vessels. These splatter protectors touch the food that is being cooked, which may result in the food becoming contaminated. Moreover, splatter protectors that sit in cooking vessels may not be suitable for use with sauces.
It would be advantageous to provide for a space saving splatter protector that reduces the clutter in kitchens and has enhanced safety and suitability for use with sauces.
Similar reference numerals may have been used in different figures to denote similar components.


An underwater trenching system comprises a closed trenching system that vacuums up sediment removed during the trenching operation and deposits that same sediment into the trench, thereby burying a pipeline that has settled into the trench. The invention provides a trenching sled having high pressure water jets for digging and a vacuum head and lines for sucking the resulting sediment into a surge tank on a barge, from which it is re-deposited by a bury sled.

I. Field of the Invention.
The present invention is directed toward an underwater trenching system. More particularly, the present invention digs an underwater trench for burying a cable or pipeline and backfills the trench using the same material that was removed to create the trench.
II. Description of Related Art.
It is frequently necessary or desirable to bury a pipe or cable at the bottom of a waterway, such as a river, lake or sea. Buried lines often include, for example, natural gas lines, petroleum products lines, fiber optic cables, telephone cables, and so forth.
Many such cables or pipelines are simply laid along the bottom of a waterway and left exposed, to be buried by the action of the currents. In other uses, a trenching tool, such as a water jet, a cutter head, or a scoop, or clam shell digger digs a trench around the pipe, which settles into the trench. The bottom matter, sediment, or spoils, blasted away by the cutting head, regardless of the type, is dispersed in the surrounding water where it remains in suspension for a considerable time before eventually settling to the bottom. The sediment may form a large cloud within the body of water, or be carried downstream many miles before eventually settling out of suspension. It has become known that the debris from such trenching operations can cause serious environmental damage to plants, animals, fishes, the water, microorganisms and so forth, particularly in fragile ecosystems.
Typically, no effort is made to cover the pipe or to fill the trench. Only the action of underwater currents may, or may not, fill the trench. In some applications, particularly those in which the trench is dug by a clam shell digger, the spoils are left alongside the trench, and later may be moved to bury the pipeline. When this technique is used, the waterway is disturbed by suspended sediment twice and to the same degree. In addition, filling the trench this way requires two passes along the entire route of the underwater pipeline, doubling the cost of labor and the commitment of capital resources.
In short, all currently known equipment and methods for underwater trenching create large clouds of silt and debris that remain in suspension for a long time and seriously disrupt the ecology of the waterway. And backfilling the trench doubles the disruption.
A typical prior art underwater excavator or trencher is shown in Notarbartolo et al U.S. Pat. No. 2,659,211, which employs an excavator having a water jet which includes an auxiliary stream for unburying a cable. The spoils are merely blasted away wherever the water jet currents take them.
Another submarine pipeline trencher is disclosed in Roy U.S. Pat. No. 3,722,224, which teaches the use of a water jet and a vacuum unit that prevents spoils from resettling into the excavated trench, but the vacuumed material is simply discharged laterally and rearwardly of the apparatus, the object being merely to keep the spoils out of the newly formed trench. A pipe-burying jet sled is disclosed in Gaspar U.S. Pat. No. 4,295,757, which employs jetting legs for the water jets and, in addition, pressurized air for enhancing removal of sediment, which is discharged directly from the apparatus into the water, thereby forming large clouds of polluted water.
Another water jet-type apparatus is disclosed in Berti et al U.S. Pat. No. 4,479,741 which sucks the spoils out of the trench through scooping units by vacuum, allowing the matter to move freely in the water away from the trench.
While these references show that it is well known to use a tool such as a water jet for creating an underwater trench, the prior art does not show any means for containing or minimizing the spread of the spoils during trenching, or for disposal of the spoils, or for re-filling the trench. It has become apparent that large clouds of spoils suspended in the waterway are a hazard to all marine life, seriously disrupts the ecology of the waterway, despoil the appearance of the waterway, and should be avoided if possible.
Accordingly, there is a need for an underwater trenching system that contains much or all of the spoils during trenching to prevent their being dispersed in the waterway; that backfills the trench after the pipe has settled into the trench, using the same spoils removed to make the trench; and simplifies the trenching and backfilling process, thereby reducing the time and cost of laying underwater pipelines and cables.

Central States Underwater Contracting, Inc.


A method and apparatus for cooling and capturing energy in an electronic device using photovoltaic cells is disclosed. A power supply powers electronic components inside the electronic device. The electronic components produce heat and infrared energy. The photovoltaic cells convert the infrared energy into an electric current to reduce the overall heat level of the electronic device. A power recovery circuit conditions the electric current into a conditioned power signal usable by a system power path manager of the electronic device. The system power path manager uses the converted infrared energy to power the electronic device and/or to charge an energy storage unit.

Electronic devices, such as mobile phones, personal digital assistants ("PDAs"), smartphones, laptops, netbooks, tablet computers, desktop computers, and various other handheld devices are performing at higher and higher levels. Electronic devices process more information than ever before, process information faster, and essentially provide an improved user experience. At the same time, electronic devices are generally becoming more compact over time, packing more components into smaller sized devices. This trend is particularly prominent with portable electronic devices. Moreover, a common theme with portable electronic devices is that users typically prefer devices that are compact and have a long battery life, which promotes simplified transporting of the device and ease of use in remote locations without requiring any connection to a power grid.
While users often prefer smaller devices with increased functionality and performance, there are some drawbacks to electronic devices of the prior art. The trend to make electronic devices more compact has caused high temperatures to be generated in smaller and smaller confined areas. As components are packed closer together, to fit into smaller device housings, there is less space for heat to dissipate from the components. Electronic components produce heat and infrared energy which are radiated from the components to their environment. If dissipated adequately, heat and infrared energy are not a problem for users of the electronic device. However, many electronic devices create an amount of heat and infrared energy that cannot always be dissipated adequately, which causes hot spots or warm areas on the device. This is particularly troublesome with portable electronic devices that are handled or carried by a user. These areas of noticeably increased temperature may be uncomfortable to users and might even be painful or harmful under certain circumstances. For example, a user may feel that a portable electronic device is uncomfortably warm when the device is in his hand, located by his ear, located in his pocket, or sitting on his lap.
The prior art methods of dealing with increased heat include various passive and active solutions. Passive solutions include heat distribution and throttling down performance or features of the electronic device. Heat distribution uses conduction of heat to various areas of the device, and can be used to maximize convective and radiated heat loss. By distributing the heat, the occurrence of hot spots is typically reduced, however, heat distribution is typically inadequate as the sole method of cooling the device.
Components in the electronic device can be throttled back or duty cycled to reduce their power consumption and associated heat generation. However, throttling back components decreases the performance of the device and/or reduces features available for the user to use. The decreased performance and features may be perceptible to the user and can deteriorate the user experience. Further, throttling devices down can add costs to the device, specifically, more expensive parts that are capable of throttling down and/or additional development time of the throttling protocol may be required.
Active solutions for removing heat include various cooling devices such as a fan, piezo vibrator, or Peltier cooler. Active solutions consume power, and thus, reduce battery time and/or overall efficiency of the device. Also, active solutions can have reliability issues, and may be an initial point of failure in a device that impedes a user's use of a device. For example, a cooling fan may become troublesome to a user, even while still cooling the device adequately, the cooling fan may produce noises that are unacceptable for using the device. Particularly for portable electronic devices, if an active solution uses significant amounts of power, reduced battery time may become a significant issue. A low battery life can seriously restrict a user's intended use of a device. Accordingly, using active solutions may require a larger capacity battery, which is typically more expensive and/or physically larger.
Accordingly, manufacturers of electronic devices face challenges in adequately cooling the devices and in prolonging battery life and/or increasing device efficiency. The prior art fails to provide a sufficient solution for the above described challenges.

Method and apparatus for cooling and energy capture in an electronic device via a photovoltaics


Various embodiments disclosed related to modified elastomer surfaces and methods of making and using the same. In various embodiments, the present invention provides a method of modifying the surface of an elastomer. The method can include contacting a polymerizable composition and at least part of a surface of an elastomer. The polymerizable composition can include a free-radical polymerizable monomers, an organoborane-organonitrogen free-radical initiator, and an amine-reactive compound. The method can include at least partially polymerizing the polymerizable composition, to provide a polymerization product of the polymerizable composition on the surface of the elastomer.

Elastomers are sometimes formed of materials with surface properties, such as texture or chemical properties, that are undesirable or less than ideal for a desired application. Modification of the surface of the elastomer can be used to improve the elastomer. Molds can be used to cause polymerizable mixtures to form various patterns on elastomer surfaces; however, the use of molds can require tedious manufacturing steps and can be limited in the types and sizes of patterns available.


A method for determining the state of occupation of a plurality of scheduled areas by vehicles, comprising the steps of: associating with each area to be monitored a transmitter which periodically transmits a signal of fixed power; receiving in a concentrator the plurality of signals emitted by said plurality of transmitters; examining said plurality of signals and determining the occupied/vacant state of each area to be monitored; periodically transmitting a signal comprising information on the occupied/vacant state of each monitored area to an operating center; generating information indicative of the state of occupation of a plurality of areas.

WO 2006/067813 describes an automatic system for monitoring and supervising the access, transit and parking of vehicles in predetermined controlled traffic zones, in particular in car parks provided with a plurality of individual parking spaces. The system comprises: an electronic vehicle identification device positioned on each vehicle, comprising a memory in which the data regarding the vehicle and/or the vehicle owner are memorized, and means enabling these data to be remotely transmitted; an electronic sensing device for the vehicle positioned in each parking space and provided with a suitable means for reading and memorizing the data present in each vehicle and means enabling these data to be remotely transmitted; at least one local data processing unit arranged to receive the information transmitted by the vehicle sensing devices, to process this information and to transmit the processed data; at least one central data processing unit, arranged to receive the information transmitted by the local data processing units, to further process the information and to further transmit the information to other processing units, in particular to data processing centres pertaining to banks or to similar financial institutions, or to directly emit signals enabling a vehicle to gain access to, to transit, or to park within the monitored zone; this automatic system is characterised in that the data transmitted by the vehicle electronic identification device are associated with the data relative to the electronic vehicle sensing device, the result of this association being transmitted to one of the local data processing units, the data processed by the local units being transmitted to the central processing unit, this latter generating a signal regarding the payment of a predetermined tariff for the access and/or transit and/or parking of a vehicle within the controlled zone. MI2008A001875, in the name of the Applicant, describes a system for verifying the state of occupation of a plurality of areas by vehicles, which comprises on board a vehicle a transmitting smart card arranged to transmit, to at least one first receiver-transmitter positioned within the area to be monitored, a first identification signal received from the vehicle.
The first receiver-transmitter is connected to a second receiver-transmitter to transmit the first identification signal and a second identification signal for the area monitored.
The second receiver-transmitter is connected to at least one electronic processor of an operating centre.
The electronic processor is arranged to receive the first identification signal and the second identification signal from the second receiver-transmitter, and to generate information indicative of the vehicle which has occupied the monitored area and of the particular area monitored.

Method and system for determining the state of occupation of a plurality of scheduled areas by vehicles


A storage component 20 for a vehicle includes a flexible component 22, such as a tambour door, formed of a plurality of slats 26 supported by and chemically bonded to a substrate 24. The flexible component 22 is translucent or transparent, allowing light to pass therethrough. The slats 26 are formed of a slat polymer, such as polypropylene (PP), and the substrate 24 is formed of a substrate polymer, such as thermoplastic elastomer (TPE). The slats 26 also have a tensile strength of at least 5 MPa so that the flexible component 22 can support objects disposed on the flexible component 22, such as an arm of a passenger or a purse.

1. Field of the Invention
This invention relates to a flexible component for storage component of a vehicle.
2. Description of the Prior Art
Automotive vehicles include numerous storage structures, such as consoles, located throughout the passenger compartment of the vehicle. For example, center consoles are typically disposed between front seats of the vehicle, and other types of consoles are often disposed along the doors or dashboard. Such consoles have doors to selectively close the storage area provided in the console. For example, an articulated or flexible door, known in the art as a tambour door, can be used to close an opening to the storage area. Tambour doors are particularly useful for closing an opening having a non-linear profile, because tambour doors can ride on tracks or rails that follow the non-linear profiles or contours of the opening. Typically, tambour doors include multiple slats or segments that fit into and ride on the tracks or rails. The consoles are often used as both a storage area and an arm rest. Passengers typically rest their arm on the door to the center console and also find it convenient to place personal items on the door.

This patent is subject to a terminal disclaimer.

Transparent/translucent flexible component for a vehicle interior


In a light source unit of an optical position detecting device, a plurality of light emitting devices are mounted on a band-shaped flexible substrate, and the plurality of light emitting devices emit detection light. The flexible substrate is arranged so as to overlap a convex face of a substrate supporting member, and accordingly, in a case where the flexible substrate is too long, the end portion of the flexible substrate can be inserted into a notch. Therefore, there is no case in which the flexile substrate floats.

1. Technical Field
The present invention relates to an optical position detecting device that optically detects the position of a target object and an apparatus provided with a position detecting function that includes the optical position detecting device.
2. Related Art
As an optical position detecting device that optically detects a target object, for example, a device is proposed in which detection light is emitted from a plurality of detection light sources toward the target object through a light transmitting member, and the detection light reflected by the target object is transmitted through the light transmitting member so as to be detected by a light receiving unit. In the optical position detecting device having such a configuration, the position of the target object is detected based on a detection result of the detection light in the light receiving unit (for example, see JP-T-2003-534554).
In addition, a method is also proposed in which a light guiding plate is arranged in an optical position detecting device, detection light emitted from a plurality of detection light sources is output toward a target object through the light guiding plate, and the detection light reflected by the target object is detected by a light receiving unit (see JP-A-2010-127671 and JP-A-2009-295318).
However, the ranges of the optical position detecting devices disclosed in JP-T-2003-534554, JP-A 2010-127671, and JP-A-2009-295318 in which the position of a target object can be detected are narrow. Accordingly, there are many problems to be solved for detecting the position of a target object in a broad area such as a screen face of a projection-type display apparatus, a screen face of an electronic blackboard, digital signage, or the like.
Here, the inventors of the invention propose a method in which a band-shaped flexible substrate having a plurality of light emitting devices mounted thereon is bent so as to position the light emitting devices in different angular directions, and the position of a target object is detected using detection light emitted from the light emitting devices. According to such a configuration, the detection light can be emitted over a wide angle range from the position in which the flexible substrate is arranged, and accordingly, the position of the target object can be detected in a broad area.
However, according to such a method, it takes extensive labor to accurately bend the band-shaped flexible substrate so as to allow the light emitting devices to be positioned in a predetermined direction, and it is difficult to fix the flexible substrate in such a state. Thus, a configuration is considered in which a substrate supporting member having a convex face is prepared, and the flexible substrate is disposed so as to overlap the convex face of the substrate supporting member. However, in a case where the position of the flexible substrate is deviated due to a deviation in the size of the flexible substrate, there is a problem in that it is difficult to detect the position of the target object with high precision due to the deviation in the position of the light emitting devices.

Optical position detecting device and apparatus provided with position detecting function


A frequency doubling circuit includes a quadrature phase generator and a mixer coupled to the quadrature phase generator. The quadrature phase generator receives a reference signal having a reference frequency and generates first and second quadrature phase shifted signals having the reference frequency. The mixer receives the first and second quadrature phase shifted signals and generates an output signal having an output frequency twice that of the reference frequency. Related methods and communications devices are also discussed.

Frequency doubling circuits are commonly used to generate a frequency doubled output signal having a frequency twice that of an input (or reference) signal. Various frequency doubling circuits are discussed, for example, in the following U.S. Patents: U.S. Pat. No. 5,475,349 to Cohn entitled "Frequency Multipliers Using Diode Arrays"; U.S. Pat. No. 5,194,820 to Besson et al. entitled "Frequency Doubling Device"; U.S. Pat. No. 4,691,170 to Riley entitled "Frequency Multiplier Circuit"; U.S. Pat. No. 5,365,181 to Mair entitled "Frequency Doubler Having Adaptive Biasing"; U.S. Pat. No. 4,048,571 to Jacobson entitled "Frequency Doubler"; U.S. Pat. No. 4,734,591 to lchitsubo entitled "Frequency Doubler"; and U.S. Pat. No. 5,552,734 to Kimura entitled "Local Oscillator Frequency Multiplier And Mixing Circuitry Comprising a Squaring Circuit". Each of these patents is hereby incorporated herein in its entirety by reference.
It is known, for example, to double the frequency of a reference signal A using a delay circuit 21 and an Exclusive-OR gate 23 as shown in FIGS. 1 and 2. In particular, the digital reference signal A is delayed by a period of time .tau. to generate the delayed signal B. The reference signal A can have rising edges occurring at times Tr and falling edges at times Tf. The resulting delayed signal B can thus have rising edges at times Tr+.tau. and the falling edges at times Tf+.tau.. Accordingly, the output of the Exclusive-OR gate 23 can have a logical 1 output during the time intervals from Tr to Tr+.tau., and from Tf to Tf+.tau., and the output of the Exclusive-OR gate 23 can have a logical 0 output during the remainder of the time when the reference signal A and the delayed signal B are both either high or low. In other words, the output signal C generated by the Exclusive-OR gate 23 will have two pulses of duration .tau. for each period of the reference signal A in effect providing an output frequency twice that of the reference signal.
In the circuit of FIG. 1, however, it may be difficult to provide an output signal C having a 50% duty cycle. In particular, the duty cycle of the output signal C is dependent on the duration of the delay .tau. provided by the delay circuit 21, and the duration of the delay .tau. may be difficult to precisely control. If a delay .tau. can be one quarter of the period (T/4) of the reference signal A, the output signal will have a 50% duty cycle. Desired accuracies may be difficult to provide, however, because of the difficulty of providing low tolerance components such as capacitors and resistors to build a delay circuit.
For example, resistors and capacitors may both be subject to semiconductor manufacturing process fluctuations resulting in 3.sigma. tolerances as great as .+-.20%. Because the delay that is implemented depends on the RC product, the combined tolerance for the delay may be on the order of .+-.40%. In other words, a designed delay of 0.25 T may have process tolerance extremes of 0.16 T and 0.36 T resulting in duty cycle extremes of 32% and 72% which are significantly different from 50% (where T is the period of the reference signal).
When providing a frequency doubled output signal for a Radio Frequency (RF) mixer in the signal path of a radio communications transceiver, an accurate 50% duty cycle may be important to suppress even order intermodulation products. Accordingly, a bandpass filter may be needed at the output of the Exclusive-OR gate 23 to suppress even order harmonics of the frequency doubled output signal C thus adding circuitry. Furthermore, suitable bandpass filters may be difficult to implement on an integrated circuit device thereby increasing the size of the system including the frequency doubling circuit and filters.
In addition, the frequency doubled output signal is often used in a differential form in Radio Frequency (RF) integrated circuit applications. Such a differential form can be provided using the circuit illustrated in FIG. 3 including delay circuits 31 and 33 and Exclusive-OR gates 35 and 37. The circuit of FIG. 3 is essentially the combination of two FIG. 1 circuits being driven by a reference signal D and its inverse D-bar. This circuit, however, is subject to the same difficulties in providing a 50% duty cycle discussed above with regard to FIG. 1. In addition, the two delay circuits 31 and 33 should be closely matched to provide outputs that are truly differential. The desired matching, however, may be difficult to achieve.
Accordingly, there continues to exist a need in the art for improved frequency doubling circuits, methods, and systems.

Frequency doubling circuits, method, and systems including quadrature phase generators


The present invention relates to a method of treating chemical pulp in order to optimize the consumption of bleaching chemicals and to improve the quality of the pulp. Especially the invention relates to a method according to which filtrate obtained from a suitable stage of the washing of brown stock preferably cooked by an alkaline cooking method is treated with an oxidizing chemical prior to the oxygen stage following the brown stock washing.

The present invention relates to a method of and apparatus for treating chemical pulp to optimize the consumption of bleaching chemicals and improve the quality of the pulp. Especially the invention relates to a method and an apparatus, by means of which filtrate obtained from a suitable washing stage of brown stock preferably produced by an alkaline cooking process is treated with an oxidizing chemical prior to the oxygen stage following brown stock washing.
In the oxygen stage carried out in medium consistency range, the amount of filtrate per one kg of pulp is 6-9 kg, and thus the properties of the filtrate have an essential effect on reactions which the pulp is subjected to in the oxygen stage, as also in the bleaching later on. So, the properties of the filtrate surrounding the pulp may have a significant effect on the chemical treatments carried out on pulp and also the disadvantageous reactions that the pulp is exposed to.
During the cooking, great amounts of organic material, mainly comprising lignin and carbohydrates originating from hemicellulose are detached off the wood fibers. Each of these organic materials has a chemical composition of its own as a result of the cooking conditions. When passing to the washing and the oxygen stage, these organic materials are carrying chemical compounds and end groups, which react with e.g. oxygen and peroxide. Thus, compounds practically inert in cooking conditions are reactive in new chemical conditions.
In most cases the oxygen stage is connected according the counter-current washing principle so that the object of the so-called brown stock washing located between the cook and the oxygen stage is to replace the liquor passed from the cook with the pulp. This liquor may be referred to e.g. washing loss and/or COD-load and is obtained as filtrate from said last washing stage, with filtrate obtained from the washing in the oxygen stage. The latter filtrate has passed through the oxygen stage with the pulp and due to that has an almost insignificant chemical potential to react with the chemicals in the oxygen stage, so that the chemicals may be used specifically for the desired reactions with the pulp. Nevertheless, some amount of black liquor components is always passed through the washing, which components play a different role than the oxidized filtrate.
In this connection, the oxygen stage refers to an alkaline stage carried out pressurized in the pressure range of 1-17 bar (abg.), and pH-range of 8.5-14, in which stage oxygen is present around the fibers at least part of the reaction time. The oxygen stage may have one, two or even more steps, whereby each reaction step comprises a reaction vessel or reaction retention effected with a tube. In practice, reaction step refers in this connection to adding and mixing some chemical used in the oxygen stage and the following retention at the tube portion. A reaction time short when practiced may thus in mathematical modeling lead to oxygen stages having four or even five steps. Reaction retentions are, depending on the applied method, from 0.1 min to 120 minutes, as the reaction retention is dependent on the desired type of reaction. In this connection, the oxygen stage is identified by a washing stage both prior to and after the oxygen stage and the fact that from the filtrate obtained from the washing after the oxygen stage usually at least part or all the filtrate is introduced to the washing prior to the oxygen stage to be used as washing liquid, so that the oxygen stage is connected countercurrently either completely or at least partially.
Most usually, oxygen and alkali and possibly some inhibitor preventing the deteriorating effect of metals on fibers is dosed into the oxygen stage, or the metals traveling with the fibers are otherwise removed or made non-reactive. The alkali charge is usually 1-60 kg ADMT (air dried metric ton) pulp and the oxygen charge 1-50 kg/ADMT pulp. The alkali that is used is most often sodium hydroxide or oxidized white liquor, but in principle all alkaline compounds containing OH-ion are alkalis which might be used in some conditions in the oxygen stage. The oxygen is dosed in gaseous form, the oxygen content most usually being 75-100% of the specific weight. The temperature in the oxygen stage is 70-120xc2x0 C. and in most cases 80-105xc2x0 C. The temperature may be raised utilizing some suitable steam having a pressure of 0.5-20 bar and hot water either via washing or dilution. The steam may be used for heating either mixed directly into the pulp or indirectly.
As to reaction kinetics, the oxygen stage is carried out so that raising the temperature and increasing the alkali charge lead to acceleration of the delignification reaction. The oxygen charge, in turn, is mainly not effected without increasing the amount of alkali. The suppliers of the oxygen stage have their own opinions about which variable is determinant in different steps and thus each supplier regulates the chemical and temperature profile according to his own desire. Nevertheless, as to reaction kinetics, in all applications the kinetics of temperature, oxygen and alkali follow one and the same basic principle.
According to our studies, the chemical reactions of the oxygen stage as a whole proceed essentially so that part of the oxygen reacts directly with the lignin compounds of the pulp and splits lignin by means of a direct reaction. Oxygen in itself is a selective chemical, which does not split carbohydrates. But in alkaline conditions part of the oxygen converts to peroxide which is very quickly decomposed to hydroxyl radicals by the effect of e.g. black liquor compounds originating from the cook. A hydroxyl radical is chemically very reactive, and the reactions thereof are not districted to reacting with lignin only, but it also causes splitting of carbohydrate chains of the pulp. Practice has shown that the selectivity or non-selectivity of a hydroxyl radical may be described e.g. so that a hydroxyl radical splits one cellulose molecule per five lignin molecules. In our experiments especially the presence of black liquor increased the degradation of peroxide and, accordingly, accelerated the forming of hydroxyl radicals at the end of the reaction chain, whereby a bigger portion of the oxygen changes via peroxide to hydroxyl radicals and thus causes damages to the pulp.
When elaborating the oxygen delignification following the washing of chemical pulp, the operation of the brown stock washing line, located in the process order prior to the oxygen stage, is usually determined so that the washing losses have to be adequately low before the oxygen stage in order to obtain a satisfactory selectivity. The term washing loss is used to refer to impurities remaining in the pulp despite the washing, which impurities in this case comprise both different chemicals and organic materials dissolved in the liquid phase during the cook. Various producers of apparatuses have different opinions on an acceptable level of washing losses. Nevertheless, prior art has not earlier performed any systematic reporting about any chemical mechanism or reason to why different washing loss levels have in different mills resulted in contradictory results concerning the effect of the impurity of the pulp on e.g. viscosity and strength properties of the pulp. This invention is based on extensive comparative studies, in which at least one significant reason for the quality losses of pulp has been determined and thus chemical reasons for quality losses of pulp found. According to said studies, the quality losses of pulp are generated as a result of the following kind of process:
The conditions in the oxygen stage generate peroxide as oxygen decomposes in alkaline condition.
Peroxide decomposes to hydroxyl radicals.
The presence of non-oxidized black liquor originating from the cook catalyses and accelerates the forming of hydroxyl radicals.
The hydroxyl radicals, due to their low selectivity, split cellulose molecules and thus cause quality losses.
In mills especially the washing loss level varies, whereby black liquor entering the oxygen stage in form of washing losses causes fluctuations in the quality.
In our studies we have noted that if the filtrate surrounding the fiber is oxidized e.g. so that it has been separately oxidized prior to feeding it into the pulp in such a way that as much as possible of the liquor around the fibers is oxidized the strong catalytic effect of black liquor originating from the cook is eliminated at the same. When as much of the liquor in the pulp has been oxidized, the quality of the pulp remains higher. Especially after 20-30 minutes the delignification proceeds selectively, even though the advantage of selectivity may be noticed right in the beginning of this stage, so that the oxygen stage may in every case be utilized in more efficient conditions than in cases where the cook-originating catalyte is present.
Prior art knows a plurality of various applications treating the filtrates of the pulp manufacturing process with an oxidizing chemical. In the methods of prior art, presented e.g. in patent publications WO-A-99/29599, EP-A-0 564 443 and FI-A-96156, the filtrate obtained from the washing following the oxygen/bleaching stage is treated with an oxidizing chemical, after which the filtrate is used as washing liquid in the wash preceding the oxygen stage. FIG. 1 illustrates as an example of prior art the solution of FI patent application 961856. The basic principle of the method described in said publication is not to prevent organic loading from entering the stage, but to decrease effluents and ensure the level of oxidizing in the circulating liquor.
Most usually prior art methods have aimed at either removing heavy metals from the filtrate obtained from pulp washing by oxidizing in order to prevent said metals from hampering e.g. the peroxide stage, or at the common to close the bleaching system of the pulp mill. Said FI publication concentrates specifically on treating the filtrate of the peroxide stage. It has been noticed that in some cases the brightness of the pulp is adversely effected when the washer following the peroxide stage discharges yellowish filtrate, which then is returned as washing liquid to the washer preceding the peroxide stage. In other words, the impurities causing the yellowish color, especially organic impurities, are recirculated back upstream of the peroxide stage. In the invention presented in said publication reveals that the yellowish color of filtrate/washing liquid may be eliminated, if the filtrate, or more exactly the organic impurities therein, are oxidized prior to returning it as washing liquid back to the washer preceding the peroxide stage. The publication suggests exhaust gas of the ozone bleaching stage to be used for the oxidizing, which exhaust gas typically contains the oxygen acting as carrier gas in the ozone stage and some residual ozone. The method according to this publication is strongly related to TCF-bleaching and participates in eliminating many problems related to TCF-bleaching.
It is our understanding that in industrial solutions, separate treatment of the filtrates of the oxygen stage with a chemical has not been performed, though. There have often been various correlations on the effect of washing losses determined by COD (chemical oxygen consumption) analysis illustrating organic washing loss on the operation of the oxygen stage as well as the quality parameters of the pulp, but the information has often been contradictory to practical results obtained from the industry. Partly this is due to e.g. the fact that it is not possible to determine the composition and origin of an oxygen-consuming material from the results of the COD-analysis.
Thinking back, in many solutions applying a two-step oxygen stage, the reasons stated experimentally in the first stage have lead to the aim of milder delignification properties without, on one hand, exactly knowing which chemical mechanisms that is based on and, on the other hand, what will be the effect of the different origin of filtrates in this wholeness. Only experiments made in the mills have proved the solutions to be right. In practice, this has meant that the black liquor filtrate passed in form of washing loss from the cook into the two-step oxygen stage has first been oxidized around the pulp fibers in conditions moderate in view of temperature so that damages to the fibers have remained as small as possible. Not until after the above presented mild first step has it been possible to arrange the conditions in the second oxygen step so that the pulp may be delignified to a low kappanumber without adverse effect on selectivity.
One observation from the experiments is that the oxygen stage itself also produces organic compounds that have a similar catalytic effect as the cook-originating black liquor, but this chemical fraction may not actually be eliminated because it is generated into the process inside said process itself.
Solutions presented in e.g. the following patent publications represent the above mentioned two-step oxygen stages utilizing the oxidation of residual black liquor:
In the solution according to U.S. Pat. No. 5,217,575 describing a two-step oxygen stage, the required temperature difference between the first and the second step is over 20xc2x0 C. so that the first step is carried out in a lower temperature, clearly less than 90xc2x0 C. With this temperature difference, the conditions of the treatment stage are made non-advantageous for the actual oxygen stage, but based on our studies they are well suitable especially for the oxidizing of filtrates. In the modification of the two-step oxygen stage according to SE patent 505141, the oxidizing of filtrates has been solved by keeping the temperature in the first reactor, i.e. the first treatment step, below 90xc2x0 C. The solution according to FI patent publication 98224 is also aimed at the same goal.
In all these solutions, the aim has been to decrease the catalyzing effect of the cook-originating filtrate on the decomposing of the peroxide compounds by dividing the oxygen stage to two or more steps and thus to improve the quality of the pulp. On the other hand, especially in old mills, installing an oxygen stage in the mill often leads to decreased operation of the brown stock washing department, whereby the amount of cook-originating non-oxidized black liquor entering the oxygen stage is increased. In such case, quality losses caused by the oxygen stage have turned out to be unexpectedly great. In addition to that, the fluctuating running conditions of the brown stock washing department, due to e.g. various bottlenecks of the mill, and disturbances in washing conditions readily lead to increased washing losses and, accordingly, to quality losses of pulp.
That is, all the above presented solutions handling with the oxygen stage utilize the treatment of the washing liquid of the wash preceding the oxygen stage, which washing liquid thus originates from the wash after the oxygen stage, with an oxidizing chemical, or the oxidizing of black liquor filtrate in a two-step oxygen delignification together with the pulp in conditions suitable for the purpose. These solutions have their problems, too, e.g. handling the heat balance. Even without heating, the first reactor of the oxygen stage operates according to the balance at a temperature of over 90xc2x0 C. and the requirement of a lower temperature of the first reactor results in the necessity of cooling the washing liquid of the washer preceding the oxygen stage. In such a case, the pulp must be heated after the first oxygen step using high-pressure steam. Heat obtained from cooling the washing water is difficult to recover in a form preferable in view of the operational economy of the fiber line. Additionally, the investment expenses and operational expenses of heat exchangers are significant. The arrangement of temperature differences in pulp production also contributes to both the forming of precipitates and the generation of extractive problems.
As the filtrate coming from the washing of the oxygen stage is already oxidized, the treatment thereof does not significantly change the situation anymore. That is why the oxidation should according to our studies be performed before the last washing stage prior to the oxygen stage, e.g. between the last and the last but one washing stages. In this way, pulp is being displaced by filtrate, oxidized in the brown stock washing, due to which the pulp is displaced by oxidized filtrate twice (the first being filtrate led as washing liquid countercurrently from the washer following the oxygen stage and the other filtrate oxidized in the brown stock washing), which results in a significant decrease in the amount of cook-originating non-oxidized liquor. Separate oxidizing of liquor entering with the pulp is actually a modification of the oxygen stage, where separate oxidation of filtrates effects especially the properties of the filtrate travelling with the pulp and enhances the access to the aimed benefits of the two-step oxygen stage. Oxidizing the liquid solution between the washers prevents non-oxidized filtrate from entering the oxygen stage also during disturbances.
Thus, the present invention is based on the idea that filtrate essentially related to brown stock washing and the oxygen stage connected thereto is treated with an oxidizing chemical so that the aim is to shut off the black liquor flow entering with the pulp from the cook as washing loss in such a way that as much as possible of the black liquor flow travelling with the pulp in form of washing loss has been gone through an oxidizing stage prior to entering the oxygen stage.
Our studies have brought to light many new ideas concerning integrating the oxygen stage between the cooking and the washing. It has been noticed that because the pulp is hot after the cooking, typically 75-100xc2x0 C., and amply of alkali is present around the pulp, the pulp is in those conditions subjected to reaction deteriorating the fibers. No special gas dosing is need for generating these reactions, but e.g. releasing pulp from the cooking to an atmospheric state is enough to cause damages. According to our studies, pulp that had been let to stand in black liquor solution at a temperature of 90xc2x0 C. in atmospheric state under a cover was significantly deteriorated measured by viscosity, without any dosing of oxygen. Thus, alkali and cook-originating black liquor components in atmospheric state together with the oxygen of air are detrimental, so that the time between the blow of the cook and the oxygen stage should preferably be as short as possible. Accordingly, it is preferable to have directly after the cook e.g. a diffuser or DRUMDISPLACER(copyright) washer and that retention in all tanks before the oxygen stage have, especially in normal running situations, been minimized as efficiently as possible. The retention time between the blow and the oxygen stage feed might at its shortest be in the range of 1-15 minutes, by means of modem technology most probably around 10 minutes and when effected by somewhat slower alternatives most usually less than 60 minutes, i.e. in the range of 20-50 minutes. That would allow the removal of cook-originating black liquor with its solid matter as soon as possible from surrounding the fibers and replace it with oxidized filtrate originating from the oxygen stage.
Characterizing features of the present invention are described in more detail in the appended patent claims.
Utilizing the method and apparatus according to the invention, e.g. the following advantages are obtained:
The amount of black liquor catalyte entering the oxygen reactor is essentially decreased.
The oxygen stage may be carried out in conditions where the portion of non-oxidized filtrate has been significantly decreased, whereby quality losses are decreases.
Uniformity of the pulp is increased, as the amount of cook-originating black liquor is reduced.
The oxygen stage may in some cases be performed in one stage, because different conditions for oxidizing the material entering the oxygen stage as washing losses are not needed anymore.
The strength of the pulp is increased.