Continuous autodeposition from a bath having a low solids concentration and stable coating characteristics is achieved by close control of bath iron concentration, preferably by maintaining iron concentration below about 1.5 gm/l by controlled discard and replacement of bath volume.

1. Field of the Invention
This invention relates to stabilized autodeposition coating baths for coating metal surfaces. In particular, the invention relates to a continuous autodeposition coating process which is economical and provides uniform coatings of high quality throughout the life of the bath.
In order to obtain an autodeposition coating bath having optimum coating efficiency, bath components consumed in the coating process must be replenished, and contaminants generated must be removed.
In the coating of steel surfaces, iron is a major contaminant, with typical iron losses to the processing bath of 20-40 mg Fe/ft.sup.2 (about 200-400 mg Fe/m.sup.2) of surface treated. In large-scale commercial applications, such losses can translate into an iron build-up in the coating bath of 100 or more grams per hour, to concentrations in excess of 3 gm/1. At these concentrations, the bath interferes with the coating process, and the entire bath, including expensive resin components present, must be discarded in favor of a fresh bath. The gradual build-up of iron within the bath also has the disadvantage of progressively altering the coating characteristics of the bath, and coatings obtained from the spent bath before discard generally vary significantly in quality from coatings obtained from a fresh bath.
2. Prior Art
None of a variety of methods for maintaining autodeposition baths at optimum efficiency has been entirely successful when applied to continuous coating operations. In particular, the addition of phosphoric acid to autodeposition baths to precipitate iron for iron control has generated a troubling sludge in some systems, which is difficult to continuously and completely remove. In addition to depleting the bath of polymer coating material, the generating sludge tends to contaminate the product film coatings, and adversely affect their corrosion-protection abilities.

Continuous autodeposition method with bath stabilization


The male connector (1) includes a connector body (10) and a lock nut (50). The connector body (10) includes a male luer (11), first female threading (41) that surrounds the male luer (11), a base end portion (20) that is inserted into a tube (8), a fixed protrusion (21) formed on the base end portion (20), and a spiral protrusion (32) between the male luer (11) and the base end portion (20). The lock nut (50) includes second female threading (52) that is screwed together with the spiral protrusion (32). When the spiral protrusion (32) and the second female threading (52) are screwed together, the base end portion (20) and the lock nut (50) clamp the tube (8). First rotation prevention mechanisms (14, 54) that engage with one another are provided on the connector body (10) and the lock nut (50) such that the lock nut (50) does not rotate relative to the connector body (10) when the tube (8) is clamped.

Enteral feeding is known as a method for administering nutrition and drugs to a patient without relying on oral administration. In enteral feeding, liquids such as nutrients, liquid food, and drugs (generally called "enteral nutrients") are administered to a patient via a transnasal catheter that has been inserted through the patient's nasal cavity and into their stomach or duodenum, or via a PEG (Percutaneous Endoscopic Gastrostomy) catheter that has been inserted into a gastrostomy formed in the patient's abdomen. The liquid to be administered to the patient is stored in a container. A bendable tube (referred to hereinafter as a "container-side tube") is connected to the outlet port of the container. The downstream end of the container-side tube is connected to the upstream end of a catheter that has been inserted into the patient (transnasal catheter, PEG catheter, or the like), or the upstream end of a bendable tube that is connected to the catheter (collectively referred to hereinafter as a "patient-side tube"). In general, a connector tool made up of a male connector and a female connector is used to connect the container-side tube and the patient-side tube. Conventionally, the male connector is provided at the downstream end of the container-side tube, and the female connector is provided at the upstream end of the patient-side tube (e.g., see Patent Document 1).
If the liquid administered in enteral feeding is a liquid that has a low viscosity, problems occur, such as the liquid flowing backwards from the stomach to the esophagus and developing into pneumonia, or the patient suffering from diarrhea caused by moisture in the liquid not being sufficiently absorbed in the body. In view of this, in enteral feeding, the liquid is often given a higher viscosity (i.e., semi-solidified) by the addition of a thickening agent or a thickener, for example. Such a liquid that has been given a higher viscosity has a low fluidity, and thus has a high resistance when passing through a tube. Accordingly, when a liquid that has been given a higher viscosity is administered to a patient, pressure is applied to the liquid to pressure-feed it.
For this reason, there is desire for the connector tool that connects the container-side tube and the patient-side tube to include lock mechanisms that engage with each other in order to be able to withstand the pressure applied to the liquid. In view of this, international standard ISO 80369-3 regarding nutrition-related medical equipment has been given consideration for the international standardization of male connectors and female connectors for use in such applications.
As shown in FIGS. 24A and 24B, a male connector 910 under consideration as ISO 80369-3 has a tubular male luer 911 and an outer tube 913 that surrounds the male luer 911. An outer circumferential face 912 of the male luer 911 is a tapered face whose outer diameter decreases as it approaches the tip (a so-called male tapered face). A channel 917 that passes through the male luer 911 along the lengthwise direction thereof is formed in the male luer 911. Female threading 916 is formed in the inner circumferential face of the outer tube 913 that opposes the male luer 911.
On the other hand, as shown in FIGS. 25A and 25B, a female connector 920 under consideration as ISO 80369-3 has a cylindrical insertion portion (female luer) 921 into which the male luer 911 is inserted. An inner circumferential face 922 of the insertion portion 921 is a tapered face whose inner diameter increases as it approaches the tip (a so-called female tapered face). Male threading 926 is formed on the outer circumferential face of the insertion portion 921.
The male connector 910 and the female connector 920 are connected by inserting the male luer 911 into the insertion portion 921 and screwing the female threading 916 and the male threading 926 together. Since the outer circumferential face 912 of the male luer 911 and the inner circumferential face 922 of the insertion portion 921 are tapered faces that have the same taper angle, they come into liquid-tight surface contact with each other. The female threading 916 and the male threading 926 that are screwed together constitute lock mechanisms for locking the connected state of the male connector 910 and the female connector 920. The male connector 910 and female connector 920 provide a connection having excellent liquid-tightness (property of preventing the leakage of a liquid from the connection portion of the male connector and the female connector even if pressure is applied to the liquid) and excellent connection strength (property of preventing separation of the connected male connector and female connector even if pulling force is applied).
In the international standard ISO 80369-3, consideration has been given to providing the male connector 910 at the upstream end of the patient-side tube and providing the female connector 920 at the downstream end of the container-side tube in order to prevent mistaken connection with a connector used in a field other than enteral nutrition.


A cell for gas-quenching a load is provided, including guiding plates and a stirring element driven by an engine to cause a gas flow between the load and an exchanger. The stirring element is an adjustable pitch blade propeller.

1. Field of the Invention
The present invention relates to a gas-quenching cell, and more specifically, to the gas stirring system for such a cell.
2. Discussion of the Related Art
Gas-quenching methods have many advantages as compared to liquid-quenching methods, especially the fact that the processed elements remain dry and clean.
The paper entitled "La vitesse de refroidissement, point capital pour le traitement en fours sous vide" by J. Naudot, published in "Traitement thermique" N.degree.133-79, France, discusses the influence of several parameters and of the gas choice on the efficiency of the quenching, mainly on the quenching speed. It is constant that if the quenching speed is to be increased, the gas mass flow, that is, its speed and its static pressure should be increased. The above-mentioned paper mentions that beyond 4 to 5 bars of static nitrogen pressure, the efficiency gain is to be tempered by the cost of the high power engines necessary for the stirring and the high gas consumption.
European patent 0,313,888 discloses using light gases, such as helium or hydrogen, at high static pressures. The power of the stirring engines would then be comparable to that reached for heavier gases at lower pressures. However, light gases are particularly expensive (helium) or dangerous (hydrogen).
The quenching efficiency, such as defined in the above documents, is relative to the quenching speed.
Gas-quenching installations are presently used only for quenching operations, since they are generally optimized to obtain as high a gas mass flow as possible.


A pressure tank includes a resin liner, a base, a seal, and a collar. The resin liner contains fluid therein. The resin liner has a tubular portion via which an inside of the resin liner communicates with an outside of the resin liner. The base includes a supply/discharge hole in which the tubular portion is inserted. The seal is provided between the tubular portion and the base in the supply/discharge hole. The collar has a through-hole and inserted into the tubular portion.

Field of the Invention
The present invention relates to a pressure tank.
Discussion of the Background
The high pressure tank is widely used as a container for containing fluid such as gas, liquid, and the like. For example, the high pressure tank is mounted on fuel cell vehicle for containing hydrogen gas in order to supply to fuel battery system.
This kind of high pressure tank has a liner configuring an outer surface covered with a reinforcing layer made of fiber reinforced plastic and a resin hollow body. A hollow tubular portion is formed and projected on the liner. A base on which a supply/discharge hole is formed for supplying/discharging fluid to the inside of the liner is installed to the tubular portion. A valve is provided on the supply/discharge hole. The supply/discharge hole is opened and closed by operating the valve.
It is common that the high pressure tank seals between the liner and the base with a seal member. For example, it is mentioned in Japanese Laid-Open Patent Publication No. 2015-31307 that according to the configuration that the tubular portion is inserted into the base, a seal member attached to an outer peripheral surface of the base can seal between the outer peripheral surface and an inner peripheral surface of the tubular portion. However, in the configuration, the internal pressure of fluid may expand the tubular portion to the separating direction from the seal member. Moreover, it is supposed that the inner peripheral surface of the tubular portion causes shrinkage deformation by creep due to the fact that the liner is made of resin material. If such a situation happens, the distance (seal gap) between the inner peripheral surface of the tubular portion and the outer peripheral surface of the base is increased, which makes difficult to gain a sufficient sealability.
For example, as mentioned in Japanese Laid-Open Patent Publication No. 2013-137092, on the contrary to the above-mentioned configuration, the other is a possible configuration that the tubular portion is arranged inside the supply/discharge hole of the base, the seal member is interposed between the outer surface of the tubular portion and the inner surface of the supply/discharge hole. In the case, the seal member is attached to the inner peripheral surface of the base, and simultaneously, the internal pressure is applied to the direction that the tubular portion is pressed to the seal member side. Accordingly, the tubular portion presses and abuts on the base and the so-called self-seal structure is formed, which can maintain a seal gap approximately constant and can favorably seal the space between the tubular portion and the base.
Moreover, according to the configuration, the pressure of fluid is applied from the tip surface side to the tubular portion, if the strength of the tubular portion is insufficient, the tubular portion is easily separated from the base. Moreover, if the shrinkage deformation of the tubular portion is generated due to temperature drop, creep, and the like, the seal gap is increased, finally which leads to the degradation in sealability. In order to prevent these, the liner mentioned in Japanese Laid-Open Patent Publication No. 2013-137092 enhances the strength of the tubular portion due to the fact that the metal reinforcement is buried inside the tip surface of the tubular portion.


An X-ray apparatus for collecting X-ray transmission data of a subject from a plurality of directions to generate an X-ray transmission image or X-ray CT image of the subject, which includes an X-ray generator for generating an X-ray, an X-ray detector for detecting a transmission X-ray after the X-ray generated by the X-ray generator is transmitted through the subject, a rotation unit for rotating an imaging unit including the X-ray generator and the X-ray detector around the subject, a data collector for converting an output signal of the X-ray detector to a digital signal and collecting the digital signal, a signal processor for subjecting data collected by the data collector to a signal processing operation, a display for displaying thereon as an image the data collected by the data collector and the data subjected by the signal processor to the signal processing operation, and a position change unit for moving a relative position of a rotation center of the imaging unit and the subject in a direction parallel to a rotation plane of the rotation, and wherein the imaging unit is rotated by the rotator around the subject and at the same time the relative position is changed by the position change unit in a direction parallel to the rotation plane to perform X-ray fluoroscopic or radiographic operation or CT scan.

The present invention relates to a method for X-ray fluoroscopy or radiography as well as an X-ray apparatus and more particularly, to a technique which is suitable for three-dimensionally measuring a large view field such as human chest in an X-ray computerized tomography (CT) scan method and an X-ray CT apparatus.
As a prior art method for measuring an X-ray fluoroscopic or radiographic image from a plurality of directions to observe or record a stereoscopic dynamic image, a rotational digital angiography (DA) or a rotational digital subtraction angiography (DSA) is described in a journal entitled "Toshiba Medical Review", No. 45, pages 2 to 11, 1992. In the journal, a C arm is provided at its one end with an X-ray image intensifier which is positioned opposed to an X-ray tube so that continuous images appear on a monitor while the C arm is rotated, whereby an operator can observe the stereoscopic dynamic images or acquire DSA images taken from a plurality of directions.
As one of general methods for obtaining a completer X-ray three-dimensional image, there is known a method in which tomographic images obtained by an X-ray CT apparatus are connected to each other through image processing. This method however has had a problem that the X-ray CT requires a lot of imaging time.
For the purpose of reducing the imaging time, there is advantageously used a cone-beam CT apparatus in which a 2-dimensional X-ray detector is used as an X-ray detector and 2-dimensional transmission images of a subject obtained through X-ray beams emitted from an X-ray source in a cone shape are use to reconstruct a 3-dimensional X-ray image of the subject.
Disclosed in a journal entitled "Medical Imaging Technology", Vol. 10, pp. 113-118, 1992 is a cone-beam CT apparatus wherein a 2-dimensional X-ray detector is made up of an X-ray image intensifier and a television camera.
Also disclosed in a paper entitled "Development of 3D CT with a large area detection system" of a journal "Radiology", Vol. 185(P), p. 271, 1992 is a large-view-field cone-beam CT apparatus wherein a 2-dimensional X-ray detector is made up of a large-area phosphor screen and a television camera.
Known a typical algorithm of reconstructing a 3-dimensional image of a subject in a cone-beam CT apparatus is the Feldkamp's method (refer to a paper "practical cone-beam algorithm" of a journal "Optical Society of America," written by L. A. Feldkamp, et al., A/Vol. 1(6), pp. 612-619, 1984).
There are also described in IEEE Transactions on Medical Imaging, Vol. 12, No. 3, pp.486-496, 1993 a method in which an imaging unit including an X-ray source and an X-ray detector is rotated around a subject and at the same time the subject is moved in a direction perpendicular to a rotation plane to enlarge a view field with respect to the rotation-axis direction of the subject, as well as a reconstruction algorithm thereof.

Method for X-ray fluoroscopy or radiography, and X-ray apparatus


A method and cleaning system is disclosed for cleaning the outer surface of a fouled microfiltration (MF) or ultrafiltration (UF) semipermeable hollow fiber membrane after its initial stable transmembrane flux has been decreased to an unacceptably low level. The method is specifically applicable to any fiber used to withdraw purified water from dirty water, particularly water containing organic matter including beneficial bacteria and/or undesirable inorganic salts, where the viability of the bacteria population is to be maintained. The membrane is cleaned by flowing a cleaning fluid, preferably a biocidal oxidative electrolyte having an oxidizing anion and an associated cation through the clean, permeate-side of the membrane, at low pressure no more than the bubble pressure breakthrough, usually <300 kPa (30 psig) for a MF or UF fiber. Such low pressure is sufficient to diffuse the electrolyte through both, the pores of the membrane and a fouling film which typically includes a biofilm accumulated on the fibers' outer surface, but not enough electrolyte flows through the membrane to kill numerically more than 20% of the living bacteria in the dirty water. This limitation can be met only if the cleaning period is brief. This period is only long enough to oxidize organic matter within the pores and kill essentially all bacteria in the biofilm. Preferably less than 5% of the bacteria population is decimated. As diffusion takes place, pores are again opened, both in the wall of the fiber and through the biofilm, and when the fibers are returned to normal operation, the restored flux is equal to at least 70% of the initial stable flux.

This invention relates to a cleaning system for substantially restoring transmembrane flux (hereafter "flux" for brevity), measured as liters of permeate per square meter of membrane surface per hour (L/m.sup.2.hr or "LMH"), in fouled, porous/semipermeable microfiltration (MF) or ultrafiltration (UF) membranes in a membrane device (module) used to recover purified water from contaminated or "dirty" water in feedstream, without draining the feed (substrate), hence referred to as an "in situ cleaning" method. A MF or UF membrane is generally used to separate one liquid, usually water, from water containing various forms of undesirable matter, some in solution and some not. Such a membrane device which is to be periodically cleaned, usually operates in "inside-out flow" in which the inner surfaces of the membranes are exposed to the feedstream of "dirty" water from which purified water is to be separated. In contrast, this invention relates to hollow fiber membranes ("fibers" for brevity) which typically operate in "outside-in" flow. By hollow fiber membranes we refer to membranes having an inside diameter (i.d) in the range from about 0.2 mm to 4.0 mm, with a wall thickness which corresponds to a particular diameter, the outside diameter (o.d.) usually being in the range from about 0.3 mm for the smallest fibers to about 6 mm for the largest.
The term "dirty" water is used herein, in a generic sense to refer to any poor quality aqueous, or predominantly aqueous solution, suspension, dispersion or emulsion. Purified water is extracted from the dirty water with a desirably high flux despite the membrane being covered, in about 8 hr or less, with a "fouling film" deposited by "foulant(s)" in the substrate. This formation of the film is also referred to as concentration polarization which is unavoidable in practice. A foulant film formed in an aqueous medium rich in microorganisms ("biomass") is termed a "biofilm", and the fouling phenomenon is referred to as "biofouling". By "rich in microorganisms" we refer to a cell count in excess of 5000 CFU/ml (colony forming units/ml). Other types of fouling occur in other applications, for example in the purification of water containing multivalent cations in the form of Ca Mg Si Fe and Mn salts (carbonates, oxides, chlorides and the like). When the fouling film decreases the desirably high flux, the membrane is cleaned to substantially restore the flux to a desirable level.
The cleaning method of this invention is particularly directed to cleaning fibers, rather than tubular membranes or spiral wound membranes. Fibers are used in a module, either in an array or in a bundle, deployed directly in a substrate without being enclosed; or, the array may be appropriately held within a shell. With fibers enclosed in a module, feed flowed through the shell side and over the outer surfaces of a multiplicity of fibers held therewithin, and emerging from the shell, is referred to as retentate or, more preferably, concentrate; and, liquid which is separated by, and flows through the microporous membrane into the lumens of the fibers is referred to as "tiltrate", or preferably, "permeate".
Restoration of the flux is effected on the permeate side of the membrane, with a cleaning fluid, most preferably an aqueous cleaning fluid, under only enough pressure, below the bubblepoint of the fiber, which for reasons given below, is believed to provide diffusion-controlled permeation. Other mechanisms may also play a part in cleaning. For example, since the membranes used herein are of a synthetic resinous material, rather than being ceramic, they are susceptible to swelling caused by interaction with the cleaning fluid.
Diffusion-controlled flow occurs at low pressure through the walls of the membranes and out into the feed (hence referred to as "inside-out flow" of a "substantially pressureless" cleaning solution). The definition of "diffusion-controlled" permeation is that which occurs at a pressure below the "bubble-pressure breakthrough" (or "bubble-point") for a membrane, and the permeating rate "J" is measured in gm-moles/sec/cm.sup.2. This definition is adapted from a method for measuring the pore sizes of a membrane by diffusion of air through water which fills the pores of the membrane at the "bubble-pressure breakthrough" for a membrane. Strictly, the pressure at breakthrough is measured by the force required to force one immiscible fluid through the pores of a membrane previously filled with a second immiscible fluid. (see Membrane Handbook edited by W. S. Winston Ho and Kamaalesh K. Sirkar, Chapter VII "Ultrafiltration" pg 426 Van Nostrand Reinhold, New York). This method was originally practiced by placing a water-filled membrane with air impingement from below. Bubbles of air penetrate the membrane into an overlying water layer. The largest pores open at the lowest pressure; thus, by slowly increasing the air pressure (1 bar/min) and monitoring air passage, a pore size distribution can be estimated. Though all pores are filled with water, gas will dissolve at the upstream face of the membrane, diffuse through the pores in solution and come out of solution at the lower pressures downstream of the membrane.
The value for the permeating rate is calculated from the following equation: EQU J=(N .pi. d.sup.2)/4 (DH) (.DELTA.P/l)
where
J=permeating rate, gm-moles/sec/cm.sup.2 PA1 N=pore density in number/cm.sup.2 PA1 d=pore diameter in cm PA1 D=diffusivity of the gas (N.sub.2) in water at 20.degree. C.=1.64.times.10.sup.-5 cm.sup.2 /sec PA1 H=solubility of the gas (N.sub.2) in water at 20.degree. C.=6.9.times.10.sup.-7 gm moles/at/cm.sup.3 PA1 .DELTA.P=pressure differential (atm) across the membrane.
For example, a membrane having a pore size of 0.27 .mu.m, a pore density of 6.times.10.sup.7 pores/cm.sup.2, and a thickness of 10.sup.-3 cm (10 .mu.m) has a diffusion rate of J/.DELTA.P=3.89.times.10.sup.-10 gm moles/sec/atm/cm.sup.2, and using the gas constant this becomes 0.0355 ml/min/psi/ft.sup.2. For a 15 ft.sup.2 cartridge tested at 30 psi the permeating rate is about 16 ml/min. (see Handbook of Separation Techniques for Chemical Engineers M. C. Porter, Appendix A).
The membrane device most preferably used for purifying non-sterile aqueous streams is a frameless array of fibers, immersed in an arbitrarily large body of water. Such a device is disclosed in U.S. Pat. No. 5,248,424 to Cote et al. An alternative is to use a device of the "shell and tube" type in which the permeate is collected from the lumens of the fibers. Such a device is disclosed in U.S. Pat. No. 5,232,593 to Pedersen et al. A device of either type is referred to herein as a "module".
When fibers are used, only the permeate flows into the lumens, and the lumens are not fouled under normal operating conditions. Therefore there is no logical reason to consider flowing a cleaning solution through the lumens.
A typical module is used to separate one liquid from another having clusters of molecules, or larger molecules than those of the liquid to be separated; or, to separate one liquid from another liquid containing a suspension or dispersion of micron-size inorganic particles or organic particles. Such particles include bacteria both dead and alive, or, a colloidal suspension of submicron size solids, or an emulsion, from which the aqueous component is to be separated.
Depending upon whether the particles are microscopic or submicroscopic in size, the membranes may have pores ranging in size from as large as 5 .mu.m (micrometers or microns) or as small as 50.ANG., and are commonly termed "semipermeable" membranes. Membranes with circumferential walls having relatively large pores are used in MF. The pores in a MF membrane range from about 300.ANG. to 20,000.ANG. in nominal diameter; and those in a UF membrane, from about 50.ANG. to about 1,000.ANG. (0.1 .mu.m).
Of particular interest herein is the separation of purified water from "dirty" water containing undesirable metal oxides, carbonates, etc. and/or a live biomass, or a non-sterile organic or inorganic "floe", the purified water passing through the walls of a semipermeable membrane into the "permeate side" of tube and fiber membranes (outside-in flow) in the module.
The fouling film is a thin continuous layer which develops on the surface of the membrane within the first 0.25-3 hr, generally no more than about 8, after the membrane is placed in operating service. Presence of the film is inferred from concentration of foulant in the substrate feed. Such concentration may be measured as the cell count in the water phase, or the concentration of metal salts, and is judged in terms of how much performance (flux) has dropped below target. The target flux is normally the initial stable flux obtained in the 9th or 10th hour, but often in the 5th or 6th, after a new membrane is contacted with dirty water. A biofilm typically comprises cells, both dead and alive, cell debris and extracellular polymer substances (EPS), with the EPS accounting for a substantial portion of the biofilm's dry mass. Wet biofilm may contain up to 95% or more of water.
In the aforementioned filtrations with membranes, the phenomenon of microdroplets of emulsifiable organic liquids, hydrocolloids and solute particles rejected by the membrane, tend to form a viscous and gelatine-like "fouling layer" which becomes part of the fouling film on the membrane even if there are no bacteria in the suspension, and there usually are. Thus, in addition to the resistance to flow of permeate due to the physical properties of the membrane, and, the boundary layer and biofilm formed under the conditions of its environment, there is the additional resistance due to concentration polarization. Since, in addition, the fouling film attracts live bacteria and permits their build-up, the flux will rapidly drop below 10 LMH, below which one cannot usually realistically expect to operate a commercial module either effectively or profitably.
When a fouling film is formed, irrespective of the source or origin of fouling, cleaning as taught herein provides such good diffusion through whatever film is left (typically essentially none) after cleaning, that the flux, after cleaning is within 30%, preferably within 20% of the flux measured after a new and unused membrane is placed in the same service for a sufficient time to exhibit a stable, and desirably high flux after an initial soak period. This soak period varies from about 0.25 hr to 5 hr depending upon the characteristics of the bacteria and suspended solids in the dirty water. This stable, desirably high flux obtained after the initial soak period is referred to as "the initial stable flux".
Up to the present time, cleaning membranes in a module referred to removing the fouling film by applying biocides, cleaners or physically scouring the membrane when membrane geometry allows. (see article titled "Biofouling--a Biofilm Problem" by H. C. Fleming, G. Schaule and R. McDonough, in Membrane Preparation - Fouling - Emerging Processes, European Society of Membrane Science and Technology, P. Aimar and P. Aptel Editors, Vol 6, 1992). Trying to restore the permeability and flux of a membrane generally requires dealing with the film formed on the surface of the membrane, unless the "dirty" water is sterile. Fleming et al did this by adding a commercial cleaner containing non-ionic and anionic surfactants which was forced through the biofilm layer and membrane. This was followed, once the permeability was constant, by washing the cleaned membranes with clean water. Their experiments were focused on determining the relative permeability of a model biofilm with different cleaners; and their effect on the relative height of the biofilm layer (cleaners had little effect).
In further experiments, they coated a membrane with biofilm by suspending the membrane in dirty water containing bacteria and a high EPS. They then exchanged the water for a cleaning agent, and filtered it until a constant permeability was seen. They then exchanged the cleaning agent for water and again filtered until a constant permeability was seen. They followed the same protocol in each case except that one set of data was measured with stirring during filtration, and the other was with no stirring. Since in each case the cleaner was filtered until a constant permeability was seen, they were unaware of how much cleaner had been filtered at that point. Further, since there was no substrate on the "other" side of the membrane during any of their filtration steps, they clearly evinced no interest in the effect of the cleaner which they had filtered. They had no reason to evince such an interest because they failed to conceive the importance of cleaning the membrane without removing substrate.
But it was known that cells in the biofilm are more resistant to biocides than those in free suspension, and that simply killing cells had little effect with reference to restoring the flux. Still further, since Fleming et al showed that enhancement in permeability due to the application of cleaner was due to an alteration of the biofilm, not removing it, it was clear that the biofilm did not have to be removed before the flux was sufficiently restored to return to normal operation.
Since the Fleming et al experimental method was an adaptation of the prior art method in which sufficient biocide was introduced into the dirty water to kill all bacteria, a desire to save beneficial bacteria rules out either method. In the prior art, in those particular instances where the bacteria were to be saved, the tank of dirty water is drained, or the membrane removed from the tank before the biocide is applied to the outside surfaces of the membranes. The problem is that though this method may kill all the bacteria, it does not generally remove the biofilm, and dead cells may stick to the biofilm, and usually do.
Most importantly, the prior art failed to realize that it was possible to kill most, if not essentially all, or only a controlled minor proportion of live bacteria in the fouling film, yet restore the flux. We deliberately kill only a controlled amount of the bacteria in the feed, but not so many as to be economically debilitating. This concept of deliberately sacrificing a controlled minor proportion of live bacteria on the feed side, outside the fouling film, to kill essentially all in the biofilm, is the essential basis of this invention.
With this concept it was feasible to employ the known principles of biocidal cleaning, namely that it improves performance because (i) cleaning with a biocide reduces the thickness of the biofilm, and (ii) biocides improve the permeation properties of the remaining biofouling film, though this second effect was underestimated in the prior art. It was because this second effect was targeted, that we realize the unexpected improvement provided by this invention.
Despite the findings of Fleming et al, the prior art failed to clean membranes in aqueous, non-sterile service (a) without either draining the dirty water to flush the membranes with a biocide, or, (b) without adding the biocide to the tank to kill all cells and withdrawing the biocide through the membrane until the flux was restored to a desirable level, or (c) without removing the membranes from their aqueous medium (dirty water reservoir) to clean them. Fleming et al sought to control development of the biofilm by control of the nutrient in the system, not by sacrificing up to 20 per cent of the live bacteria in the feed in the interest of flux restoration sufficient to justify return to normal operation.
Thus, to date, it has not been possible to restore the flux of a biofouled membrane without leaving an objectionable concentration of cleaning fluid (solids are unusable in lumens) in the dirty water, even if one was prepared to kill all cells. Much less was it possible, substantially to restore the flux without killing more than a controlled amount of live cells in the biomass, while killing essentially all those cells which clog the pores of the membranes.
In most membrane-separations of dirty water to recover purified water, dirty water is passed over the outer surfaces of small diameter organic or inorganic hollow fiber membranes, or through tubes, or, through a roll, and the desired liquid is recovered as a permeate which passes through the membrane and flows out the permeate-side of the membrane device. Despite the effectiveness of fibers, tubes and rolls for making a desired separation, all are so easily and badly fouled that whether such membranes can be used economically depends upon how well the fouling material ("foulant") can be quickly removed, sufficiently to restore their initial stable flux, or, to restore the flux to as close to that initial level as practical.
Because the surprisingly effective method disclosed herein for cleaning membranes uses a cleaning fluid which is most preferably a liquid biocidal oxidizing liquid, and it contacts the lumens of the fibers at low, negligibly small fluid velocity, if any, and typically at less than 1 meter/see through the lumens, the fibers are under only enough internal pressure to cause gentle permeation of the cleaning fluid through the membrane and fouling film. It is critical that the pressure for such gentle permeation be below the membrane's bubble point.
This limitation applies whether the cleaning fluid is recirculated, held stagnant, or pulsed. Because under recirculation or pulsed conditions the cleaning fluid is in laminar flow, the method is also referred to as "in situ diffusion cleaning". Such cleaning occurs even when the fluid is simply held in the fibers at no velocity, under only enough pressure to allow the fluid to diffuse through the membrane into the reservoir in which the membrane is immersed. It also occurs under low pressure (below bubble point) pulsing of the cleaning fluid to urge the fluid to take a path other than through already-clean pores, thus to improve distribution of the fluid on the permeate side, and to vary the flow pattern of distribution of fluid as the membrane's flux is restored. Since in each case there is very little flow of biocidal solution through the lumens of the fibers, and in one case (velocity=0 meter/sec) there is none, the cleaning system of this invention does not require a conventional holding tank such as used in a prior art clean-in-place system. The biocidal liquid in our system may be dispensed from a container the fluid volume of which is only slightly greater than that of the sum of the lumens of all the fibers to be cleaned simultaneously, or the sum of the bores of all the tubes, or all the spiral passages. The solution is recirculated when it returns to the container.
A further unexpected advantage is that there is no need to counteract or recover the cleaning fluid which diffuses into the feed since that amount is too small to be objectionable, typically less than 10 ppm in a reservoir of substrate, and is biooxidized at that low concentration, negating biocide build-up.
The importance of being able to maintain the surface of a membrane clean enough to make its use in a separation process practical was the primary topic of a symposium held a decade-and-a-half ago and reported in a chapter titled "Fifteen Years of Ultrafiltration" by Michaels, A. S. in Ultrafiltration Membranes and Applications edited by A. R. Cooper (American Chemical Society Symposium, Washington, 9-14 Sept. 1979, Plenum Press, New York (1980). A flux of at least 20 LMH, preferably 50 LMH, is generally desirable in commercial separations, the higher the flux, better; and as stated above, a flux below 10 LMH is generally deemed unacceptable for the purpose at hand.
The unremitting search over the past fifteen years, for better systems to provide clean working surfaces on a membrane for long period of time, at least clean enough to provide a commercially acceptable flux, has been singularly unrewarding. As a result much energy and time has been spent on the development of semipermeable membrane compositions which are less readily fouled than ones providing comparable duty in the same or an analogous service.
To clean deposits left on a membrane when dirty water (outside-in flow) contacts its outer surface, as it most often does, two cleaning methods are now generally used. A first method relies on cleaning a fouled outer surface from the outside; the second relies on cleaning the fouled outer surface from the inside. In such prior art methods the outer surface may be that of a fiber, or a tube, or a roll; the method of this invention is mainly applicable to fibers.
In the first method which relies on cleaning a fouled outer surface from the outside, the fouled surfaces are scoured, sometimes after a soaking period in a cleaning solution made up of specific chemicals. Scouring is effected by a suspension of finely divided solids which have essentially no affinity for the membrane, the solids having a diameter larger than the largest pores in the membrane so as not to be trapped therein, the scouring action being controlled by the rate at which the suspension is flowed over the membrane surfaces.
An alternative first method uses a chemical cleaning solution to remove the solid or semi-solid matter which is deposited on the membrane's outer surface. Such a cleaning solution is aptly formulated to dissolve or chemically react with the organic or inorganic matter deposited on the membrane. A drained module may be soaked in the solution, or the solution may be recycled through the shell-side of the module until the fouling matter is chemically degraded and dislodged. It will be understood that in outside-in flow, the permeate side of the membrane (the lumens of fibers) does not get fouled because essentially no solids pass through a membrane.
To clean the exterior by exercising either of the above options, the feed must be shut off, and the module is preferably taken out of service and drained, before the chosen cleaning fluid in the appropriate concentration, is introduced in lieu of the feed. The cleaning solution is recycled over the surfaces of the membrane until they are cleaned, then discarded to drain. If a bioreactor is available, the cleaning solution is collected and gradually bled into the bioreactor where the chemicals and fouling solids are biodegraded.
Representative conventional clean-in-place systems without draining the feed are illustrated in articles titled (i) "Improved Product Rinsing Efficiency with Multitubular Ultrafiltration" by W. J. Allshouse and Masatake Fushijima, ELECTROCOAT '84, pg 14-1 to 14-13; (ii) "New Developments in Ultrafilter System Design" by Mark Rizzone, ELECTROCOAT '88, pg 11-1 to 11-39; in a reference manual titled "Koch Spirapak Electrodeposition Paint Ultrafiltration Modules" published June '89 by Koch Membrane Systems, Inc.; and in bulletins "ZPF8-Series Ultrafiltration Systems" and "LF-Series Reverse Osmosis Systems from 60 to 300 gpm" published by Zenon Environmental Systems Inc. Most recently a liquid back-washing system has been used for fibers in which permeate is withdrawn in outside-in flow. The fibers are cleaned by flowing a solution of cleaning agent through a bundle of fibers after the flow of the solution is blocked. There is no enablement of diffusion-controlled flow. No bacteria population is stated to exist in the medium, nor is there concern for maintaining the bacterial population. (see Japanese patent publication JP 4-265127A, Sept 1992).
It is important to note that reference to "back-washing" or "back-flushing" fibers in the prior art does not refer to recirculating liquid through the lumens of fibers because the pressure drop of cleaning solution through the lumens is so high. The fact that diffusion-controlled permeation did not require a substantially pressurized solution escaped notice. Because it is impractical to recirculate even a low viscosity liquid such as DI water through hollow fibers, the conventional method of "back-flushing" on the inside was with blocked fibers, that is, dead-ended under pressure in excess of the bubble point, or by the gas-distension method referred to herebelow, also under pressure in excess of the bubble point.
The second method for cleaning porous, elastic, hollow fibers from the inside, is the popular gas-distension method. This method comprises introducing a gas into the fibers under sufficient pressure to pass through the walls of the fibers, in a direction opposite to that in which the feed is being filtered, so as to dislodge solids retained on the walls of the fibers. This method is the subject of U.S. Pat. Nos. 4,767,539 and 4,921,610 to Ford, and related patents assigned to Memtec Limited. According to the '539 and '610 processes, for "outside-in" flow, gas is introduced into the lumens of the fiber as the back-wash medium, optionally after "back-flushing" ("back-washing" and "rinsing" are two other terms used interchangeably in the art with back-flushing) with permeate. Preferably the gas pressure in the lumens swells fouled fibers to enlarge their pores making it easier to free the particles lodged in the pores, and to carry them away in the expansion of the back-wash gas. Such a system is commercially available as a Memcor microfiltration system (Memtec).
To use the gas-back-flushing system effectively it is desirable to have highly elastic membrane walls which have pores which return to their original size after "explosive decompression" of gas through them. In such instances, one may first use a permeate back-flush and follow it with a gas back-flush. The chief drawback of the intermittent gas-pressurization process is that it places great strain on the membrane and relies on mechanically dislodging fouling matter which, for the most part is adhesively bonded to the membrane wall with physico-chemical forces such as Van der Waal's forces and the like, and perhaps also with covalent bonds.
As will be seen from the data presented in FIG. 5, back-flushing a polysulfone fiber at 175 kPa with permeate, or even deionized RO water, is far less effective than diffusion-cleaning with an oxidative anion such as a halogen, e.g. fluorine, chlorine, bromine or iodine. To obtain the desired explosive decompression of gas through the pores, the permeate side of the membranes is shut off, or "dead-ended".
Another, and older, method of cleaning fouled hollow tubes in particular, from the inside without draining the feed, requires back-flushing with permeate under relatively low pressure, particularly limited by the tolerance of the membrane to hydraulic pressure. The phrase "relatively low pressure" refers to pressure exerted by the gas-cleaning system which uses sufficient pressure to distend the membrane and dislodge foulant particles trapped in the membrane pores. As one would expect however, because back-flushing relies on loosening solid particles on the surface by forcing them off with hydraulic forces, it is not as effective as short bursts of pressurized gas. The hydraulic forces act over a much longer period of time than do the forces of a pressurized gas, and the time during which they act provides enough time for the hydraulic fluid to find a path of less resistance than that of the path blocked by fouling solids.
The hydraulic back-flushing system is also referred to as "dead-end" washing because the discharge of the manifold carrying fluid from of the bores of the fibers is blocked to allow the build-up of necessary hydraulic pressure above 240 kPa. The cleaning solution is held for a period of time under pressure, then drained through the discharge into a spent cleaning-solution tank.
This prior art back-flushing method is only effective when the cleaning solution is relatively non-toxic because a large portion of the cleaning agent escapes through pores which are not plugged, or only partially plugged, and also through pores after they are cleaned and before the hydraulic pressure is removed. Since, after cleaning fibers in raw or "dirty" water, by back-flushing with toxic cleaning solution, clean water is withdrawn into the fibers as permeate, the toxic cleaning solution re-enters the fibers with the permeate. Even if the amount of cleaning agent re-entering with permeate is insignificantly small, a far greater amount of cleaning agent is used than is necessary to effect desirable cleaning. Finally, in the special instance where the fibers are withdrawing water from a medium containing live biomass, particularly a biomass which desirably helps purify the water, the discharge of a relatively large amount of toxic cleaning solution into the biomass kills so many cells that it takes an abnormally long period to return the biomass to its desired cell concentration, if it can be returned at all.
Further, to cope with the release of excess cleaning agent into the water to be purified, the cleaning agent is used infrequently, compensated by frequent back-flushing with permeate. Whether by forward or reverse flow, permeate helps significantly to maintain clean membrane surfaces. But back-flushing with permeate recycles it at the expense of permeate production and can only be justified when the cleaning effect of back-flushing is great enough to overcome the economic disadvantage. Thus substituting cleaning agent for gas in the '539 and '610 processes fails to provide a controllable, diffusion-controlled, substantially pressureless cleaning system.
Moreover, back-flushing a membrane's outer surfaces with biocidal solution, then back-flushing inner surfaces with permeate, is generally limited to processes in which the operating transmembrane pressure is relatively low, in the range from 1-3 bar, at which low pressure the solids are not forced into the pores of the membrane. In those instances when the flux is relatively low, in the range from 5 to 20 LMH, the fluid velocity of cleaning fluid to clean from the outside is too low. If cleaned with high velocity fluid the cleaning liquid enters the lumens, making this an unrealistic alternative.
It will now be appreciated that the cleaning systems which can be operated effectively without draining the feed, include those using pressurized back-flushing with a biocidal solution, such as in the Japanese system of JP 4-265127A and those using pressurized back-flushing with a gas, such as in the Ford '539 or '610 gas-distension systems.
It is not practical to back-flush fibers with permeate because the cleaning effect of permeate is solely due to hydraulic pressure and is therefore relatively ineffective. Further, to obtain a minimum liquid velocity of 1 meter/see of permeate through a lumen 1 mm in diameter, at a pressure below the bubble-point of the membrane, the pressure drop through the lumen is so high that a length of fiber only 1 meter, requires fiber-bursting pressure at the inlet to generate a pressure below the bubble-point, at some point downstream of the inlet. When the pressure does not exceed that which can be tolerated by the fibers, tubes or rolls, and they are back-flushed with permeate at such pressure, permeate is lost to the feed.
In the other methods, if the fibers are to be cleaned from the outside, the feed is shut off and drained, as is the permeate, the fibers are soaked in cleaning solution, washed and rinsed, on their outside surfaces, then finish-rinsed with fresh permeate before the membranes are returned to service.
Specifically with respect to hollow fiber membranes having an inside (lumen) diameter in the range from 0.5 mm to 5 mm, the feed is always on the outside. The i.d. of a fiber is at least 20 .mu.m and may be as large as about 3 mm, typically being in the range from about 0.1 mm to 2 min. The larger the o.d., the less desirable the ratio of surface area per unit volume of fiber, but the lower the pressure drop for a back-flushing cleaning fluid. The wall thickness of a fiber is at least 5 .mu.m and may be as much as 1.2 mm, typically being in the range from about 15% to about 60% of the o.d. of the fiber, most preferably from 0.5 mm to 1.2 mm.
The average pore cross sectional diameter in a fiber may vary widely, being in the range from about 5.ANG. to 10,000.ANG.. The preferred pore diameter for ultrafiltration of components in a substrate feedstream being in the range from about 5.ANG. to 1,000.ANG.; and for microfiltration, in the range from 1,000.ANG. to 10,000.ANG..
It will now quickly be evident that a module containing fibers, whether held in arrays framed in wafers or frames, or held in oppositely disposed manifold means or "headers" in frameless arrays, may be viewed as being analogous to a liquid-liquid shell-and-tube heat exchanger. To clean fouled tubes in the exchanger is only possible in the unique situation where a first liquid is recycled through the tubes either to heat (or cool) a second liquid in the shell side, and the tube side gets frequently fouled. In this situation one may switch from recycling the first liquid to recycling a cleaning solution which can provide substantially the same heating (or cooling) function as the first liquid. After an appropriate amount of time, when the fouled tubes are clean enough, the cleaning solution is run into a cleaning solution holding tank and the first liquid is substituted.
Moreover, if one were to consider it, in the same manner as one might consider flowing cleaning solution through large diameter membrane tubes, the logical approach would be to pressurize the fibers with the cleaning solution from within, to reap the benefits of both (a) a higher flux for the cleaning solution, and (b) enlargement of the pores such as is obtained with the gas pressurization process. The obvious way to pressurize the fibers is to "dead-end" them, that is, to block the discharge of the cleaning solution from the outflow end of the lumens so as to force the cleaning solution out of the pores under high pressure greater than the bubble point of the membranes.
Assuming the membrane's performance is unaffected by an arbitrarily large number of dead-end back-flushing cycles, the problem with such cleaning is that it uses far more cleaning solution than is necessary, and is time-consuming compared to our cleaning method. Apart from the expense, since cleaning solutions are far from inexpensive, they are also highly toxic to bacteria which one may deliberately wish to keep in a biological treatment system containing plural frameless arrays, for their ability to biodegrade contaminants which may be present in the water.
An obvious drawback of cleaning from the outside of a tube or fiber, rather than from the inside, is that to do so requires a shell. If there is no shell, as in a frameless array such as one disclosed in the '524 array must be removed from the process reservoir in which it operates and immersed in a cleaning solution in another tank. An alternative is to drain the process reservoir and to substitute cleaning solution; then drain the cleaning solution after cleaning, and refill the reservoir. As is evident, this is a highly undesirable alternative.
Further, cleaning from the outside of a tube or fiber requires a large volume of cleaning solution since the system holdup volume must be filled. The permeate side volume is very small in comparison. Finally, any cleaning solution applied to the outer surface of a tube or fiber from the outside, is typically done under sufficient pressure to force the solution from outside the membrane through the biofilm on it and its pores. To save on time in the cleaning cycle, a relatively high pressure is applied, higher than is otherwise necessary, and such pressure has the effect of compacting the gel layer and foulants on the membrane wall, thus exacerbating the cleaning problem. Cleaning from the inside, particularly with continuous recirculation through the fibers, avoids using a higher pressure than is necessary to permeate the membrane wall, that is, a pressure no higher than that required to produce laminar flow on the membrane's permeate side, until its surface is sufficiently clean as evidenced by the restoration of a desirable flux.

In situ cleaning system for fouled membranes


A gas turbine system with a heat recovery cycle includes a gas turbine unit that produces hot exhaust gases which are applied to a heat recovery heat exchanger containing a working fluid responsive to applied hot gases for producing vaporized working fluid and cooled gases which are vented. A turbine connected to a generator and responsive to the vaporized working fluid generates power and produces expanded working fluid. A condenser condenses the expanded vaporized working fluid to condensate which is returned to the heat recovery heat exchanger. A control device (94) controls the temperature of the applied hot gases, based on a sensed temperature (89) and include mixer apparatus (87) for mixing ambient air with the hot exhaust gases and producing a mixture of hot exhaust gases and ambient air before the mixture is applied to the heat recovery heat exchanger.

Gas turbines have been used for producing power in many installations around the world. Often, the exhaust gases of the gas turbine are merely exhausted into the atmosphere. For example, high pressure natural gas transmission pipelines are conventionally used for transporting gas from production fields to customers remotely located from the fields. Gas compressors feeding such pipelines usually are powered by a gas turbine, and optionally, a heat recovery cycle can be employed to reduce the net power requirement by converting waste heat in the hot exhaust gases from the turbine into electricity. An installation of this type is illustrated schematically in FIG. 1 which shows a two stage air compressor producing compressed air that is supplied to a gas turbine coupled to a utilization device, such as a gas compressor. In such an installation, a portion of the compressed gas supplied by the compressor is bled into a combustor and burned in the compressed air before the resultant combustion gases are applied to the gas turbine.
The temperature of the hot gases that exit the gas turbine can be about 450.degree. C., and these gases usually contain sufficient heat to make heat recover economically justifiable. Conventionally, the exhaust gases are applied to an indirect contact heat exchanger containing water which is vaporized. The resultant steam is supplied to a steam turbine coupled to a generator that produces electricity, and expanded steam that exits the turbine. The expanded steam is condensed in a condenser that usually is supplied with cooling water from a pond associated with a cooling tower.
During cold weather, ambient temperature may drop below freezing causing the cooling water and the steam condensate to freeze thus interfering with the functioning of the condenser and the cooling tower. When this occurs, operation of the heat recovery cycle must be terminated.
Recent improvements in organic vapor turbine design and construction have suggested that an organic vapor turbine using an air-cooled condenser might be used to replace the steam turbine in the installation described above. This would have the advantage of permitting the heat recovery cycle to remain operational during the coldest weather. However, the high temperature of the exhaust gases and the characteristics of organic fluids (e.g., pentane) used in organic vapor turbine cycles raises the possibility that a relatively hot portion of the heat exchanger could result in carbon formation and deposition due to the excess heating of the organic fluid by the hot exhaust gases.
It is therefore an object of the present invention to provide a new and improved gas turbine system with heat recovery cycle and a method for using the same which overcomes or substantially ameliorates the problem described above.

Gas turbine system and method using temperature control of the exhaust gas entering the heat recovery cycle by mixing with ambient air


An environment controllable scanning probe microscope (SPM), such as a scanning tunneling microscope (STM), atomic force microscope (AFM), etc., in which the gaseous environment of the sample during the observation is controllable. That is, the gas surrounding the sample can be replaced to a desired one and the pressure can be set to a desired value. The SPM is suited for observing biological samples because biological samples may deteriorate under a reduced pressure and the surface topography at such high magnification is vulnerable to contamination from the environment.

In a scanning tunneling microscope (STM), which is a typical SPM, a surface topography of a sample is observed using a needle-like probe called "tip" whose apex is placed in the proximity of the sample surface (the gap between the apex of the tip and the surface of the sample is of the order of 1 nm=10.sup.-9 m). The tip is fixed to a tip scanning driver which moves the apex of the tip in the x, y and z directions (where z is the direction parallel to the tip) using piezoelectric actuators. A certain voltage (about .+-.0.1-3 V) is applied between the tip and the sample to cause a tunneling current to flow between them. While the tip is scanned through the x-y plane, the tunneling current is maintained constant by properly moving the tip in the z direction, whereby the surface topography is obtained. The resolution of the STM can be up to the dimension of atoms.
Conventional STMs are mainly used for observing non-biological samples such as metals, semiconductors, etc., in which case the sample is placed in a highly evacuated chamber and the surface is cleaned by heating the sample to a high temperature or a cleaved new surface is produced.

Environment controllable scanning probe microscope


A new and distinct variety of apricot tree is disclosed and which is mature for harvesting and shipment under the ecological conditions prevailing in Eastern Washington, about August 15th.

The present invention relates to a new and distinct variety of apricot tree, 'Prunus armeniaca', and which has been denominated varietally as 'F194 cv' hereinafter, and more specifically to a new apricot tree variety which is characterized as to novelty by bearing large, light orange-colored fruit which have some pinkish red blush. This new variety of apricot tree is also notable for producing fruit which are ripe for harvesting and shipment at least about 3 weeks later than other common apricot varieties such as "Perfection" (not patented) under the ecological conditions prevailing in Eastern Washington.


A light weight foldable weight lifter's bench. The bench is equipped with adjustable barbell receivers and a positionable back support. A fold up frame supporting a hard backed padded top bench pad can be quickly folded nearly to a flat position for storage in minimal storage areas such as under a bed.

1. Field of the Invention
This invention relates to portable benches equipped for weight lifting. The present invention is particularly directed towards a weight lifter's bench having supports for barbell exercising and the bench being sufficiently foldable for easy storage under a bed.
2. Description of the Prior Art
Past art patents illustrate a variety of weight lifter's benches having various types of take-a-part structure and changeable platforms. A foldable platform with the versatility of the immediate invention was not seen in patents found in a past art patent search conducted in the classes and subclasses 272/144, 141, 134, 126, 118, 68, 67, and 123. Those patents considered most pertinent to our invention included the following:
1. U.S. Pat. No. 3,545,748, dated Dec. 8, 1970, issued to Delinger. An adjustable slant board is shown in this patent.
2. In a patent dated Jul. 4, 1978, U.S. Pat. No. 4,098,502, a multi-purpose exercising bench is illustrated which converts to many uses without requiring use of tools.
3. U.S. Pat. No. 4,423,865, issued to Mahnke on Jan. 3, 1984, is further illustrative of weight lifter benches having adjustability. The Mahnke bench illustrations do not show foldability for storage.
4. The Baynes "saddle" shown in U.S. Pat. No. 4,412,678, dated Nov. 1, 1983, shows a weight lifter's bench with the upper portion of the back rest adjustable relative to the bar receiver. No fold up features are shown.
5. The wind load device shown in U.S. Pat. No. 4,705,267, issued to Jackson on Nov. 10, 1987, is a rather complicated exercising station which can be taken apart and reassembled for different uses. Although the exerciser can be dismantled in a variety of pieces, the take-a-part sections are directed towards use changes rather than simple mechanics for storing the device.
6. The exercising table shown in U.S. Pat. No. 4,609,192. dated Sep. 2, 1986, does shown a foldable table with provisions for storing parts snapped to holders under the table. The fold up mechanics appear very similar to those used in most folding picnic tables and some parts must be separated from the table to accomplish the folding.
7. The Baswell collapsible gym apparatus shown in U.S. Pat. No. 4,431,181, dated Feb. 14, 1984, is an exercising device which can be folded into a storage cabinet.
The foregoing seems typical of the art found in adjustable and folding weight lifter benches shown in past art patents. No completely foldable weight lifter's benches having barbell receivers which fold up with the bench were seen in the past art patents nor are any available in the market place at the present time.


The hydrostatic transmission control system includes a first and second two-position solenoid valve which function to alter the hydraulic fluid parameters as delivered to the servo control cylinders of a variable displacement pump associated with a hydrostatic transmission. Activation of the first solenoid valve instigates a varying of pump displacement. Once the desired pump displacement has been achieved, the second solenoid valve is activated to maintain the desired pump displacement. The deactivation of both solenoid valves results in the hydrostatic transmission seeking and maintaining a neutral mode.

This invention relates generally to a hydrostatic transmission control system and, more specifically, to a hydrostatic transmission control system which is operable to effect a variation in the displacement of the hydrostatic transmission.
It is common practice to utilize mechanical and hydraulic controls to vary the effective displacement of the pump unit of a hydrostatic transmission. In addition, some electrohydraulic controls have been utilized to regulate the displacement of the hydrostatic transmission. Electrohydraulic controls have proven to be more accurate than mechanical or hydraulic controls; however, electrohydraulic controls have a higher cost associated with them. A major contributing factor to the cost of electrohydraulic controls is the number and type of hydraulic valves which are utilized in the conventional electrohydraulic control system. For example, one of the valves within the conventional electrohydraulic controls is a direct control valve or spool valve, which valves are expensive and sensitive to contaminants. In order to enhance the comparative position of electrohydraulic controls to the other known hydrostatic transmission control systems, it is desirable to minimize the number and complexity of valves utilized in the control systems without sacrificing system accuracy.
The present invention discloses a hydraulic control system which employs a reduced number of valves which are less sensitive to contaminants and simpler in design.


A lubricator includes a pump body configured to include a cylinder, an inlet passage, a first outlet passage and a second outlet passage, a piston configured to include an inlet port, a circumferential groove and an inner passage, and inserted into the cylinder, first to fourth check valves provided on the inlet side of the inlet passage, the outlet sides of the first and second outlet passages and the inner passage of the piston, a lubricant containing unit connected to the first check valve, and a piston driving unit configured to reciprocate the piston.

In general, lubrication pumps are used to supply lubricant, such as grease or oil, to lubrication target points in a variety of rotating machines, such as electric motors, pumps, and blowers. In this case, the lubrication target points chiefly refer to bearings that are used for the purpose of supporting the rotating shafts of rotating machines.
FIG. 1 is a view showing an application of a conventional lubrication pump. A conventional typical lubrication pump is a small pump, which has a single outlet. Accordingly, the lubrication pump itself can supply lubricant to a single lubrication target point.
However, a typical rotating machine, such as a motor M shown in FIG. 1, has two lubrication target points because both ends of a rotating shaft A are supported by respective bearings B. Accordingly, in the case of the conventional art, two lubrication pumps are generally applied to the single rotating machine M, as shown in FIG. 1. In other words, the conventional art has problems including inefficiency and higher cost because two lubrication pumps are required to lubricate a rotating machine.
In another conventional art that uses a lubrication pump and also a special valve, such as a distributing valve, can make lubricant discharged from one single outlet of the lubrication pump be separately discharged to two outlets through the distributing valve. However, since the distribution valve is added to the single pump, this technology also has problems in that installation is complicated and costs are increased.
In still another conventional art, a passage can be divided into two passages by applying a member, called a tee, to a single outlet of a lubrication pump. However, this application has a problem in that different amounts of lubricant are apt to be supplied to two lubrication points though they require the same amount of lubricant because the resistances of line produced in the respective passages cannot be kept the same.


An interface for interfacing an accelerator control input, a service brake control input, and a parking brake control input with a hybrid electric vehicle's electric control system that controls propulsion of the vehicle by controlling the motor torque output of an electric traction drive motor that drives driven wheels of the vehicle. The application of either the service brakes or the parking brake concurrent with the accelerator pedal being at non-idle causes the interface to override the motor torque being requested by the accelerator control input in favor of a zero motor torque request to the control system.

A representative, electric-powered, wheeled, automotive vehicle has an on-board electric motor whose motor torque output provides torque input to a drivetrain that includes driven wheels supporting the vehicle on a surface along which the vehicle travels. A known electric power source for the motor comprises an on-board compliment of D.C. batteries. The drivetrain delivers the torque to the driven wheels, thereby propelling the vehicle along the underlying surface.
A representative, engine-powered, wheeled, automotive vehicle has an internal combustion engine that provides torque input to the drivetrain, and that torque is transmitted through the drivetrain to the driven wheels that propel the vehicle.
An HEV is like an electric-powered vehicle in that torque output of an electric motor provides torque input to the drivetrain. It differs however in that it has an alternative power source for the electric motor, that is additional to an on-board compliment of D.C. batteries. That alternative power source comprises an internal combustion engine that drives an electric generator. As the engine runs, it operates the electric generator, and in turn, the generator delivers electricity to run the electric motor.
An HEV also has an electric control system that may include distinct, but inter-related, sub-systems for controlling operation of the electric motor, operation of the internal combustion engine, operation of the electric generator, and re-charging of the D.C. batteries. The control allows the options of operating the vehicle by use of D.C. battery power, or of operating the vehicle by running the engine to operate the electric generator. The engine may also operate the electric generator to re-charge the batteries.
A suitable electric motor is a traction motor. The electric motor may be a D.C. motor or an A.C. one. Likewise, for the generator. Depending on particular choices for the motor and generator, the electric control may include rectifiers and/or inverters for converting one form of electric power into the other.
An HEV may be similar to an internal-combustion-engine-powered automotive vehicle in having like control inputs available to the vehicle driver, including an accelerator control input, a service brake control input, and a parking brake control input, each of which can be operated by the driver independently of the others. Each control input includes an actuator such as a hand-operated pull or lever, or a foot-operated pedal. For example, depressing an accelerator pedal from an idle position accelerates the vehicle, depressing a service brake pedal applies the service brakes, and depressing a parking brake pedal, or pulling a parking brake handle, applies a parking brake.
The service brakes are typically fluid-power-operated, with each wheel having its own brake mechanism. The parking brake may be a mechanical, non-fluid-operated mechanism, or mechanisms, proximate a portion, or portions, of the drivetrain. Because of the independent operability of each of the three control inputs, it is possible that either one of the brakes may be applied while the accelerator pedal is being depressed.
"Two-toed" operation of the service brake pedal and the accelerator pedal may potentially damage, and/or shorten the life of, involved components. Applying the parking brake while the accelerator pedal is depressed would be considered undesirable for similar reasons. Having the accelerator pedal depressed as the parking brake is being released would also be considered undesirable.
In one respect, the present invention is directed to solutions for avoiding potential problems due to simultaneous operation of an accelerator and a brake in an HEV.
One general aspect of the invention relates to an automotive vehicle comprising: a drivetrain, including wheels for supporting the vehicle on a surface along which the vehicle is propelled; an on-board electric motor that, when operated, delivers torque output through the drivetrain to driven ones of the wheels for propelling the vehicle along such a surface; an on-board internal combustion engine; an on-board electric generator; an on-board D.C. power supply; an electric control system for controlling the electric motor, including the application of electric power input to the electric motor selectively from the generator and from the D.C. power supply respectively; an accelerator control input for requesting motor torque output from the electric motor; a service brake control input for selectively applying a service brake associated with one or more of the wheels; a parking brake control input for selectively applying a parking brake associated with the drivetrain; and an interface for interfacing the accelerator control input, the service brake control input, and the parking brake control input with the electric control system to control propulsion of the vehicle. The interface comprises a service brake interface portion for detecting application of the service brake by the service brake control input, a parking brake interface portion for detecting application of the parking brake by the parking brake control input, and an interface output portion for causing the electric control to operate the electric motor such that no motor torque output is delivered through the drivetrain from the motor when either brake interface portion detects application of the respective brake by the respective brake control input.
Another general aspect of the invention relates to an automotive vehicle comprising: a drivetrain, including wheels for supporting the vehicle on a surface along which the vehicle is propelled; an on-board electric motor that, when operated, delivers torque output through the drivetrain to driven ones of the wheels for propelling the vehicle along such a surface; an on-board internal combustion engine; an on-board electric generator; an on-board D.C. power supply; an electric control system for controlling the electric motor, including the application of electric power input to the electric motor selectively from the generator and from the D.C. power supply respectively; an accelerator control input for requesting motor torque output from the electric motor; a brake control input for selectively applying a brake associated with the drivetrain; and an interface for interfacing the accelerator control input and the brake control input with the electric control system to control propulsion of the vehicle. The interface comprises a brake interface portion for detecting application of the brake by the brake control input and an interface output portion for causing the electric control to operate the electric motor such that when the brake interface portion detects application of the brake by the brake control input, the motor torque output is rendered insufficient to cause propulsion of the vehicle along the surface.
Still another general aspect of the invention relates to a method of operating an automotive vehicle that has: a drivetrain, including wheels for supporting the vehicle on a surface along which the vehicle is propelled; an on-board electric motor that, when operated, delivers torque output through the drivetrain to driven ones of the wheels for propelling the vehicle along such a surface; an on-board internal combustion engine; an on-board electric generator; an on-board D.C. power supply; an electric control system for controlling the electric motor, including the application of electric power input to the electric motor selectively from the generator and from the D.C. power supply respectively; an accelerator control input for requesting motor torque output from the electric motor; a brake control input for selectively applying a brake associated with the drivetrain; and an interface for interfacing the accelerator control input and the brake control input with the electric control system to control propulsion of the vehicle, the interface comprising a brake interface portion for detecting application of the brake by the brake control input, and an interface output portion. The method comprises causing the electric control to operate the electric motor such that when the brake interface portion detects application of the brake by the brake control input, the motor torque output is rendered insufficient to cause propulsion of the vehicle along the surface.
More specific aspects of the invention will been set forth in the ensuing description, claims, and accompanying drawings.
The drawings, which will now be briefly described, are incorporated herein to illustrate a preferred embodiment of the invention and a best mode presently contemplated for carrying out the invention.

Brake activated torque disable in hybrid electric vehicles

Navistar International Transportation Corp.


An endoscope system in which a normal observation image and a near observation image are photographed by a solid-state image sensor upon operation of a focus adjustment device for changing a focal length and a working distance satisfies:

1) Field of the Invention
The present invention relates to an endoscope system that is provided with a photographing optical system using a solid-state image sensor.
2) Description of Related Art
In recent years, electronic endoscopes using solid-state image sensors such as compact CCDs have become popular. Since such an endoscope allows a plurality of persons to observe lesion in a body cavity via a TV monitor, examination and diagnosis can be made by a plurality of medical doctors. Also, it is greatly advantageous to patients also in that they can view their own lesion while being informed of doctor""s diagnosis. Of such endoscopes, so-called xe2x80x9cmagnifying endoscopexe2x80x9d, which is used for near observation of lesion to facilitate examination of its minute structure for the purpose of determining the degree of infiltration of the minute lesion or the regional extent to be subjected to incision, has drawn particular attention most recently.
Some of optical systems for the magnifying endoscopes are disclosed, for example, in Japanese Patent Publication (KOKOKU) No. Sho 61-44283 and Japanese Patent Application Preliminary Publication (KOKAI) No. 4-218012. Each of these optical systems are three- or four-unit-type optical systems and are able to provide high magnification, while involving a problem in that the entire length of the optical system is considerably long, to cause bulkiness of the insertion section of the endoscope and thus to impose a great burden on a patient.
Also, such a magnifying endoscope of prior example has a drawback in that it has an extremely narrow depth of field and thus has poor operability.
Here, brief explanation is made of the definition of depth of field. FIG. 16 is a sectional view of an endoscope optical system taken along the optical axis. As shown in the drawing, placing a CCD at a position where an image I of an object O is formed makes it possible to obtain an in-focus image. If the object O is moved toward the endoscope to the position Oxe2x80x2, the image I is shifted to be formed at a position Ixe2x80x2. On the other hand, if the object O is moved away from the endoscope to a position Oxe2x80x3, the image I is shifted to be formed at a position Ixe2x80x3. Where the position of the CCD is fixed, the image Ixe2x80x2 or the image Ixe2x80x3 at the position of the CCD becomes a circle of confusion with a diameter xcex4, to cause an out-of-focus image. However, if the resolution of the CCD is greater than the diameter xcex4 of the circle of confusion, image quality is determined by the resolution of the CCD and, accordingly, the object-position range from Oxe2x80x2 to Oxe2x80x3 seems to be in focus. This range is called xe2x80x9cdepth of fieldxe2x80x9d, where a distance Xn from the optical system to the point Oxe2x80x2 is defined as the nearest distance in the range of the depth of field, while a distance Xf from the optical system to the point Oxe2x80x3 is defined as the farthest distance in the range of the depth of field.
In this case, the following equation is true:
|1/Xnxe2x88x921/Xf|=2xcex4Fno/fL2xe2x80x83xe2x80x83(1)
where the effective aperture ratio (F number) is represented by Fno and the focal length of the optical system is represented by fL2.
Here, the depth of field D is given by:
D=Xfxe2x88x92Xnxe2x80x83xe2x80x83(2)
If we regard Xn, Xf as two values of the variable X of the function 1/X=Y, we can view a value of the operation on the left of Equation (1) in the form of a difference in Y direction between two points that lie on the curve of 1/X=Y shown in FIG. 17. If the value of 2xcex4Fno/fL2 is constant, a smaller value of Xn, or the near observation condition yields a smaller depth of field D1.
To be specific, the depth of field of a magnifying endoscope in the magnifying mode is as narrow as 2 mm or 3 mm. Such a specification would require, for example, an operator to perform subtle manipulation on the order of 1 mm while the endoscope being inserted into the large intestine over lm deep. In short, it requires a lot of skill to manipulate the endoscope (Problem 1).
Also, in the conventional magnifying endoscope system, the same image processing is performed in the normal observation mode and in the magnifying observation mode. In general, when a tissue is magnified, minute lesion in it also is observed as magnified and thus the image provided for observation would contain a large amount of low-frequency components. In contrast, since an endoscopic image in the normal observation mode shows a web pattern of fine blood vessels at a low magnification, the image provided for observation would contain a large amount of high-frequency components. Therefore, if the image processing that is optimized for the magnifying observation mode is employed in the normal observation mode, the image of the blood vessels collapses to be hardly observable (Problem 2).
Furthermore, according to the conventional magnifying endoscope, a part of the optical system located 1 m or more away is driven via a wire for switching between the normal observation mode and the magnifying observation mode. No medical doctor but the operator can know the magnification currently selected and thus there may be difference in recognition regarding the size of the lesion among them. Resultantly, it is difficult for them to make a discussion (Problem 3).
The present invention has been made in consideration of the above-mentioned problems involved in the conventional art. An object of the present invention is to provide an endoscope system which is made compact so as to impose less burden on a patient, is provided with a wide depth of field so as to allow even a person without considerable skills to easily manipulate the system in the magnifying observation mode, is able to improve accuracy of diagnosis information by enhancing seeming resolution regarding the magnified information, and is able to improve accuracy of diagnosis by facilitating discussion among a plurality of medical doctors.
In order to attain the above-mentioned object, the endoscope system according to the present invention is configured to photograph an image obtained in the normal observation mode and an image obtained in the near observation mode on a solid-state image sensor by controlling a focus adjustment means which changes the focal length and the working distance and to display the image on a display unit, wherein the following conditions are satisfied:
WDwide greater than WDtelexe2x80x83xe2x80x83(3)
fwidexe2x89xa7ftelexe2x80x83xe2x80x83(4)
where fwide is a focal length in the normal observation mode, WDwide is a working distance in the normal observation mode, ftele is a focal length in the near observation mode, and WDtele is a working distance in the near observation mode.
In general, where fL is a focal length of an optical system, fF is a front-side focal length of the optical system and z is a distance from the surface of the optical system to an object, magnification xcex2 of the optical system is given by:
xcex2=xe2x88x92fL/(fF+z)xe2x80x83xe2x80x83(5)
Accordingly, for the purpose of securing as large a magnification xcex2 as possible, it is necessary to set the distance z as short as possible or to set the focal length fL as long as possible.
On the other hand, as explained above regarding Problem 1, if the distance z from the surface of the optical system to the object is set short or the focal length fL is set long, the depth of field becomes narrow, to make the system less operable. Condition (3) is specified, according to the present invention, so that the requirement for the magnification and the requirement for the depth of field are compatibly satisfied. This is a minimum necessary condition for securing a sufficiently high magnification. In performing magnifying observation, a medical doctor would spread coloring over lesion so that the lesion is viewed in high contrast. However, this treatment would attenuate light reflected back from the object, sometimes to make the visual field dim. If only Condition (3) is satisfied, this problem of dimness can be dealt with, because an illumination lens also can be located near the object, to improve brightness.
Condition (4) is specified, according to the present invention, for the purpose of securing as wide a depth of field as possible. As is known from Equation (1), depth of field increases with decreasing focal length fL in inverse proportion to the square of fL. Therefore, the focal length in the magnifying observation mode is set to be small to satisfy the condition fwidexe2x89xa7ftele, for the purpose of widen the depth of field and, simultaneously, the endoscope is positioned near the object to satisfy Condition (3) for the purpose of increasing magnification. In this way, simultaneous satisfaction of Condition (3) and Condition (4) can provide a magnifying endoscope that achieves high magnification and wide depth of field for convenience in use.
Also, an endoscope system according to the present invention is provided with a control device that supplies a control signal based on a signal from a solid-state image sensor to a focus adjustment means, wherein, on the basis of the control signals, control of switching between image processing modes is made in accordance with the situation of the optical system.
In general, in the near observation mode, the image contains low-frequency components because a pattern peculiar to the lesion is observed with a high magnification. Therefore, enhancing the low-frequency components facilitates determination of the pattern of the lesion and thus is preferable.
On the other hand, the endoscopic image in the normal observation mode contains high-frequency components because a web pattern of minute blood vessels is photographed with a low magnification. Therefore, in the normal observation mode, enhancing the high-frequency components facilitates determination of the web pattern of the blood vessels and thus is preferable.
Conventionally, only an operator who manipulates the endoscope is able to know which of the near observation mode and the normal observation mode is currently selected. Therefore, in order to optimize the above-mentioned two image processing modes in compliance with the selected observation mode, the operator has to judge the status himself and make switching manually, which is bothersome. In contrast, according to the present invention, since switching between the near observation mode and the normal observation mode is electrically controlled by the control device, determination of the selected mode is made on the basis of the control signal and switching is performed automatically. Whereby, two kinds of image processing modes for near observation and normal observation can be properly selected without confusion so as to improve accuracy of diagnosis information by enhancing seeming resolution regarding the magnified information.
Furthermore, an endoscope system according to the present invention is provided with a control device that supplies control signals based on signals from a solid-state image sensor to a focus adjustment means, a calculating device which calculates, on the basis of the control signals, optical amounts corresponding to the status of the optical system, and a display unit which displays a result of the calculation generated by the calculating device.
As described above, the optical system of the endoscope is designed to have a relatively wide depth of field. To be specific, it has an observation range varying from 5 mm wide to 100 mm wide. On the other hand, as expressed by Equation (5), the magnification of the optical system is the function of the distance z to the object and the focal length fL, and thus the optical magnification associated with the depth of field 5 mm and the optical magnification associated with the depth of field 100 mm greatly differ.
Ideally, it is desirable that the dimensions of lesion are definitely determined. However, unless the distance to the lesion is known, the optical magnification cannot be determined. In this case, measurement methods typically including triangulation are not preferred because application of such a method would result in bulkiness of the endoscope distal end section.
Detailed analysis of requirements of medical doctors"" has revealed that, besides accurate dimensions of lesion, common recognition among the medical doctors regarding magnification range of the object image currently in focus would remove misunderstandings in discussion among them and thus can improve accuracy of diagnosis.
According to the present invention, switching between the near observation mode and the normal observation mode is electrically controlled by the control device, where optical information peculiar to each of the near observation mode and the normal observation mode is calculated on the basis of the control signals so as to be displayed on the display unit as useful information. Whereby, since which of the near mode and the normal mode is the current observation mode and optical amounts, which typically include the magnification, in the current mode are available on the display, it is possible to provide an endoscope system which would preclude possible misunderstandings among the medical doctors and thus would improve accuracy of diagnosis.
This and other objects as well as features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings.

Abstract: WDWide greater than WDtele

Abstract: where fwide is a focal length in a normal observation mode, WDwide is a working distance in the normal observation mode, ftele is a focal length in a near observation mode, and WDtele is a working distance in the near observation mode. Whereby, the endoscope system is provided with a wide depth of field so as to allow even a person without considerable skills to easily manipulate the system in the magnifying observation mode, is able to improve accuracy of diagnosis information by enhancing seeming resolution of the magnified information, and is able to improve accuracy of diagnosis by facilitating discussion among a plurality of medical doctors.