Abstract: An ammonia purification system includes a hydrocarbon removal station that removes hydrocarbons from gaseous ammonia via adsorption, a moisture removal station that removes water from gaseous ammonia via adsorption, and a distillation station including a distillation column connected with a condenser to facilitate removal of impurities from ammonia and condensation of gaseous ammonia to form a purified liquid ammonia product. The system further includes a storage tank to receive purified ammonia, a remote station connected with the storage tank, and a vaporizer connected with the storage tank. The vaporizer is configured to receive and vaporize liquid ammonia from the storage tank and deliver gaseous ammonia back to the storage tank so as to facilitate pumping of the ammonia to the remote station based upon a vapor pressure established within the storage tank.

Abstract: An apparatus and process for supplying low pressure oxygen-enriched gas to a patient and at a moderate pressure to a radial compressor, whereupon it is compressed and fed to a high pressure storage tank. The oxygen-enriched gas is prioritized so that it is continuously supplied via a patient flow line to the patient.

Abstract: A plurality of different layers of filter media are used to remove siloxanes from a gas stream. Based on an analysis of the specific gas stream to be filtered, a filter media having an average pore size enabling the preferential removal of a specific class of contaminants is selected for each different class of contaminants. The layers are arranged in sequential order such that contaminants having a higher molecular weight are preferentially removed by the first layers. Collectively, the layers define a segmented activity gradient that enables each class of contaminants present in the gas stream to be preferentially removed in a different layer, preventing removal competition between different classes of contaminants. A polymorphous graphite is used as the filter media, because that material is available in a range of well-controlled pore sizes, as opposed to conventional activated carbon filter media, which generally exhibits poorly-controlled pore sizes.

Abstract: The invention provides a humidity control system (HCS) to control indoor humidity within a specified range so as to reduce indoor house-dust mite allergen levels. The invention also provides a hydrogel absorber/desorber for reversibly absorbing water vapor from air releasing water vapor to air. The invention employs a reversible hydrogel desiccant as the active element for absorption and desorption of water, thus rendering the HCS more effective and energy-efficient than traditional humidification/dehumidification systems. The HCS of the invention treats indoor air by drawing fresh air in from outside and adjusting the humidity of the air-stream. In certain embodiments, fresh air is drawn in from the outside and mixed with recirculated air. The HCS uses a controller to introduce fresh air into the interior space and to control air circulation within it. Relative humidity is monitored remotely throughout the interior space using wired or wireless sensors.

Abstract: The present invention relates to a gas recycling system that includes a) a source of gas having a predetermined purity; b) an application system that uses the gas and adds contaminants to the gas; c) an adsorption system for removing the contaminants from the gas to produce a purified gas and a waste gas; d) a gas purity analyzer for measuring the amount of the contaminants in the waste gas; and e) conduits connecting the gas source to the application system, and the application system to the adsorption system.

Abstract: A method of reducing the sorbate concentration of a process fluid stream using a sorption bed system includes the following steps. A mass of a sorbent material is rotated so that, in a cycle of operation, a given volume of the sorbent mass sequentially passes through first, second, third, fourth, fifth, and sixth zones, before returning to the first zone. A process fluid stream is passed through the sorbent mass in the first zone, and a regeneration fluid stream is passed through the sorbent mass in the fourth zone. A first isolation fluid stream is recycled in a closed loop, independent of the process fluid stream and the regeneration fluid stream, between the sorbent mass in the second zone and in the sixth zone. A second isolation fluid stream, meanwhile, is recycled in a closed loop, independent of the process fluid stream, the regeneration fluid stream, and the first isolation fluid stream, between the sorbent mass in the third zone and in the fifth zone.

Abstract: A gas generation method and apparatus, capable of use in an aircraft, generates oxygen with at least one On Board Oxygen Generating System (OBOGS) and generates an inert gas with at least one On Board Inert Gas Generating System (OBIGGS) and selectively supplies an auxiliary supply of inert gas utilizing a waste gas output of the at least one OBOGS. The inert gas can include nitrogen. An auxiliary source of oxygen can also be provided. Control valves can be used to selectively supply the waste gas output of the at least one OBOGS to the atmosphere or to either of two locations. The oxygen can be used in a passenger compartment of the aircraft and the inert gas used in either a fuel tank or cargo bay of the aircraft.

Abstract: A dust collection apparatus includes a container and a suction pump that sucks dust and transports it into the container. A filter is provided on a side surface of the container. This filter passes air but prevents passage of the dust in the container. A pressure detector detects an internal pressure of the container. The internal pressure of the container fluctuates due to a variation in an effective area of the filter for allowing the air to pass according to the dust collected and accumulated in the container. A dust accumulating quantity calculator which determines a quantity of the dust in the container based on the pressure detected.

Abstract: A method and apparatus for supplying dissolved gases (such as oxygen, ozone, chlorine etc.) for chemical and biological processes is described. The methods and apparatus described are particularly suitable for use in the biodegradation of organic matter (such as in municipal and industrial wastewater treatment), and other uses. The apparatus may comprise a dissolved gas supply system.

Abstract: An apparatus for generating an oxygen enhanced gas by removing nitrogen gas from air, includes a compressor, absorption columns for removing the nitrogen gas from the pressurized air supplied from the compressor, a flow rate measuring device provided downstream of the absorption columns, a manner of measuring ultrasonic oxygen concentration that includes a manner of generating a correction coefficient for a ratio between oxygen and argon gases contained in the oxygen enhanced gas based on the flow rate of the oxygen enhanced gas measured.

Abstract: A compact and highly portable combination pressure swing adsorption apparatus and product gas conservation device for medical use, to produce efficiently a gas with a high concentration of oxygen and to deliver the oxygen concentrated gas to a user at selectable times and in selectable doses.

Abstract: An air or oil dryer module is provided to remove or reduce moisture from a lubricant using a pressurized air supply to inject dry air into a lubricant sump. As the “dry air” or air with a minimized moisture content, gathers moisture from the lubricant a relative humidity sensor detects an increase in air moisture. At a pre-determined relative humidity level, a fresh supply of air is added into the lubricant sump, purging the higher relative humidity level air from the sump. A method of reducing moisture content of a lubricant contained in an enclosed space is also disclosed and is performed by agitating the lubricant, providing a humidity sensor in fluid communication with the enclosed space, measuring the humidity of the enclosed space and comparing the humidity measurement with a pre-selected humidity level, introducing dry air into the enclosed space if the humidity level equals or exceeds the pre-selected humidity level, until the saturated humidity level is less than the pre-selected humidity level.

Abstract: A gas separation method and apparatus that recovers efficiently principal gas components from a feed gas that includes a plurality of components, and enables supplying the product gases continuously at a stable flow rate and component concentration. A first separation step using a first adsorption column and a second separation step using a second adsorption column are provided, a circulating feed gas, consisting of the recovered exhaust gases discharged in each of the steps and the feed gas, is used as a gas to be separated. The outflow rate and component concentration of a second gas product are maintained constant by controlling the outflow rate of the first gas product.

Abstract: A hydrocarbon adsorbent state determining apparatus is provided for compensating the ability of a hydrocarbon adsorbent to adsorb moisture for fluctuations due to a change in the flow velocity of exhaust gases to accurately determine the state of the hydrocarbon adsorbent, including a deterioration thereof, irrespective of the change in the flow rate of exhaust gases. The hydrocarbon adsorbent state determining apparatus determines the state of a hydrocarbon adsorbent disposed in an exhaust system of an internal combustion engine for adsorbing hydrocarbons and moisture within exhaust gases.

Abstract: Environmental control equipment is provided for a developing apparatus for developing a light-exposed resist film with a developer in a wafer treating chamber. An air supply means, supplying air taken from outside into the wafer treating chamber, includes a chemical contaminant removal means for removing chemical contaminants from the air.

Abstract: This invention provides systems and methods of supplying oxygen-enriched air to an enclosed space or compartment. The systems and methods may distill oxygen from ambient air by a molecular sieve pressure cycle mechanism, such as a pressure swing absorption, may generate oxygen from water using electricity or may use oxygen enriched air produced by membrane filtration. The invention helps people improve their wellness, productivity and comfort, improve performance of mental and/or physical tasks, increase their alertness, quality of life and pleasure, reduce their drowsiness, and aid in curing and preventing disease by increasing the percentage of oxygen in the enclosed space to a beneficial and safe level.

Abstract: A system for recovering water from the atmosphere includes water sorbent assembly composed of a water adsorbent material and a heat exchanger. The water adsorbent material traps water present within the air drawn through the sorbent assembly. Once the sorbent assembly is fully saturated, exhaust gases generated from a power plant are routed through a heat exchanger in thermal contact with the water adsorbent material to remove water within the sorbent assembly into a condenser, and from the condenser to a water storage container.

Abstract: A method of operating a life support system for an aircraft, the system including a plurality of oxygen supply apparatus, each of which in use is operable to supply product gas, which may be pure oxygen or oxygen enriched gas, to a breathing gas supply apparatus, at least one of the oxygen supply apparatus being a main oxygen supply apparatus and the remainder of the oxygen supply apparatus being auxiliary oxygen supply apparatus, the main oxygen supply apparatus being operable independently of the auxiliary oxygen supply apparatus, characterized in that the method includes operating the main oxygen supply apparatus and supplying product gas to each of the auxiliary oxygen supply apparatus.

Abstract: Apparatus and method for abatement of effluent from multi-component metal oxides deposited by CVD processes using metal source reagent liquid solutions which comprise at least one metal coordination complex including a metal to which is coordinatively bound at least one ligand in a stable complex and a suitable solvent medium for that metal coordination complex e.g., a metalorganic chemical vapor deposition (MOCVD) process for forming barium strontium titanate (BST) thin films on substrates. The effluent is sorptively treated to remove precursor species and MOCVD process by-products from the effluent. An endpoint detector such as a quartz microbalance detector may be employed to detect incipient breakthrough conditions in the sorptive treatment unit.

Abstract: A system and method for passive hypoxic training provides a person with a low oxygen (hypoxic) environment. Oxygen sensors automatically monitor and control oxygen levels to maintain the altitude desired. CO2 levels are monitored and CO2 is eliminated so that the air a person breathes is substantially clean and fresh. Exposure to a high altitude environment produces physiological changes in a person's body, which becomes more efficient at absorbing and transporting oxygen. Using the present method and system, athletes obtain the benefits of sleeping at a simulated altitude in the user's own home for six to twelve hours, rather than traditional altitude therapies in which athletes spend two to three weeks at high altitude before an athletic competition to obtain similar benefits. This system allows for “live high train low” altitude training that has been shown in controlled studies to provide superior benefits to “live high train high” training.

Abstract: The invention comprises a gas recycling system comprising: a) a source of gas having a predetermined purity (28); b) an application system (6) that uses said gas and adds contaminants to said gas; c) an adsorption system (1) for removing said contaminants from said gas to produce a purified gas, and a waste gas; d) a gas purity analyzer (100) for measuring the amount of said contaminants in said waste gas; e) conduits ((5), (8), (9) (13) and (15) connecting the gas source (4) to said application system, said application system (6) to said adsorption system.

Abstract: The present invention is directed to a gas sampling system for conducting respiratory gases from a patient respiratory gas output mechanism to a respiratory gas monitoring device. A gas sampling tube is coupled to an input connector. The gas sampling tube is configured to conduct the respiratory gases from the patient to the gas monitoring device. An output connector couples the gas sampling tube to the monitor input connector. An output dryer tube is coupled between the gas sampling tube and the output connector. The output dryer tube is characterized by a tube length and a relative moisture removal efficiency. The relative moisture removal efficiency is dependent on the tube length. The tube length is selected to limit the moisture content of the respiratory gasses being directed into the respiratory gas monitor to a predetermined level.

Abstract: A compact and highly portable combination pressure swing adsorption apparatus and product gas conservation device for medical use, to produce efficiently a gas with a high concentration of oxygen and to deliver the oxygen concentrated gas to a user at selectable times and in selectable doses.

Abstract: A method to control the performance of desiccant dryers is disclosed that senses multiple variables and optimizes the regeneration cycle to deliver the gas at the desired dew point. The length of the stripping step is reduced or eliminated depending on the desired set point and the operating conditions of the compression system. The control system has the capability to switch to high efficiency mode of operation should the dew point set point be changed. The savings come from not purging as much or any gas during stripping should the system requirements be only to meet the ISA standards for instrument air, despite the system capability of delivering far dryer air.

Abstract: A compact and highly portable combination pressure swing adsorption apparatus and product gas conservation device for medical use, to produce efficiently a gas with a high concentration of oxygen and to deliver the oxygen concentrated gas to a user at selectable times and in selectable doses.

Abstract: A system and method for controlling carbon dioxide (CO2) emissions emanating from a gas source includes a CO2 sorbent bed containing a regenerable sorbent. Exhaust gases flow through the CO2 sorbent bed before being released into the atmosphere. The CO2 sorbent bed traps CO2 contained within the exhaust gas to control the amount of CO2 finally exhausted to the atmosphere. At least two CO2 sorbent beds are used such that while one is absorbing CO2 from the gas stream another is being regenerated. The CO2 sorbent bed is regenerated to release the trapped CO2 for disposal or use in other processes. The CO2 sorbent beds are cycled between absorbing CO2 and regenerating to optimize absorption of CO2.

Abstract: An air purifier discharges air directly to a room without forcing the air to pass through a HEPA filter when the level of contaminations in the air, such as dust particles, is determined to be sufficiently low. The air purifier thus minimizes air pressure loss and attenuates operational noise caused by the HEPA filter, through which air passes. In an aspect, the air purifier includes a main body defining an air passage therein to allow sucked air to pass therethrough prior to being discharged, and a first filter installed in the main body to be switched between a dosed state and an open state. The first filter removes contaminants from the sucked air in the dosed state, and allows the sucked air to pass smoothly through the air passage in the open state.

Abstract: This invention provides systems and methods of supplying oxygen-enriched air to an enclosed space or compartment. The systems and methods may distill oxygen from ambient air by a molecular sieve pressure cycle mechanism, such as a pressure swing absorption, may generate oxygen from water using electricity or may use oxygen enriched air produced by membrane filtration. The invention helps people improve their wellness, productivity and comfort, improve performance of mental and/or physical tasks, increase their alertness, quality of life and pleasure, reduce their drowsiness, and aid in curing and preventing disease by increasing the percentage of oxygen in the enclosed space to a beneficial and safe level.

Abstract: A method and apparatus for abatement of effluent from a CVD process using a source reagent having a metal organic loosely bound to a organic or organometallic molecule such that upon exposure to heat such bond is readily cleavable, e.g., copper deposition process involving the formation of films on a substrate by metalorganic chemical vapor deposition (CVD) utilizing a precursor composition for such film formation. The abatement process in specific embodiments facilitates high efficiency abatement of effluents from copper deposition processes utilizing Cu(hfac)TMVS as a copper source reagent.

Abstract: This invention includes a pair of chambers each containing a piston which is reciprocated slowly by a computer controlled reversible fluid pressure pump between an advanced position for moving room air through a molecular sieve bed to strip nitrogen from the air and deliver oxygen enriched air to a patient, and a retracted position to back-flush the sieve bed with oxygen enriched air and exhaust the nitrogen rich air to the atmosphere. The pistons may be moved by piston rods or by a rack and pinion drive. In a third embodiment a single cylinder forms a pair of chambers separated by a central exhaust chamber, and expandable bellows in the chambers extend and retract either alternatively or simultaneously. In a fourth embodiment a single cylinder containing a single piston forms a pair of chambers one on each side of the piston and a molecular sieve bed communicates with each chamber.

Abstract: A gas removal filter has an ion exchanger for adsorbing a gas and at least a pair of electric resistance measuring electrodes disposed on the ion exchanger. By measuring a change in the electric resistance between at least the pair of electric resistance measuring electrodes disposed on the ion exchanger, it is possible to estimate an ion exchange group consumption ratio of the ion exchanger. The ion exchange group consumption ratio of the ion exchanger can be detected in a short period of time, and a remaining adsorption capability of the ion exchanger can be known with ease.

Abstract: An air quality monitoring arrangement is associated with an enclosed cab of an agricultural tractor used for towing or carrying spraying implements for treating crop with substances which might be toxic or otherwise harmful to people. A signal from a contaminant sensor is sent to a control arrangement which compares the actual sensed contamination of the air within the cab over time with a value from a performance map representing the performance expected from normal performance of the air circulating system of the cab. When the sensed contamination is higher than that of the performance map the operator is warned of a malfunction. The blower of the air circulating system may have its speed increased so as to pressurize the cab so as to exclude the entry of contaminated air through seals and other small openings of the cab.

Abstract: An air purification device has an oxygen-supplying function, in which air in an automobile is sucked by a vacuum pump and purified by a dust collector or an adsorbent such as activated carbon and zeolite, and oxygen is enriched in air to supply oxygen enriched air into the automobile. The air purification device enriches oxygen in air according to a VSA (vacuum swing adsorption) process using a difference between pressure in the adsorption bed and atmospheric pressure, in which nitrogen adsorbed into the adsorbent is release using the vacuum pump. The air purification device has an air filter for removing impurities from air sucked from an inside of the automobile by the vacuum pump, an adsorbent for adsorbing nitrogen from air passing through the air filter and passing oxygen, and an oxygen tank for storing oxygen supplied from the adsorbent and releasing oxygen using a vacuum.

Abstract: An oxygen concentrator system includes at least one oxygen concentrator sub-system and a plenum subsystem. The at least one oxygen concentrator sub-system produces oxygen-enriched air which is outputted to both the oxygen concentrator system output and to a plenum chamber within the plenum subsystem. The plenum chamber is trickle charged with the oxygen-enriched air when the at least one oxygen concentrator sub-system produces an excess amount of oxygen-enriched air. Should the demand for oxygen-enriched air exceed the capability of the at least one oxygen concentrator sub-system, additional oxygen-enriched air is provided by the plenum chamber until such time that the capability of the at least one oxygen concentrator sub-system exceeds the demand of oxygen-enriched air. At that time, oxygen-enriched air is no longer provided by the plenum chamber but rather the plenum chamber is again trickle charged.

Abstract: An oxygen concentrator system with altitude compensation includes at least one oxygen concentrator sub-system and a plenum subsystem. The at least one oxygen concentrator sub-system produces oxygen enriched product which is outputted to both the oxygen concentrator system output and to a plenum chamber within the plenum subsystem. The plenum chamber is trickle charged with the oxygen enriched product when the at least one oxygen concentrator sub-system produces an excess amount of oxygen enriched product. Should the demand for oxygen enriched product exceed the capability of the at least one oxygen concentrator sub-system, additional oxygen enriched product is provided by the plenum chamber until such time that the capability of the at least one oxygen concentrator sub-system exceeds the demand for oxygen enriched product. At that time, oxygen enriched product is no longer provided by the plenum chamber but rather the plenum chamber is again trickle charged.

Abstract: An air demoisturizer for an oil expansion vessel of an electrical power unit like an oil-filled transformer, tap changer or choke, has a heating element in the body of absorbent and utilizes a heat-regeneratable absorbent which is cut off by a moisture detector from the oil expansion vessel when the absorbent is saturated and is thermally regenerated. The demoisturizing column is provided in line with an oil receiver through which the dry air is passed before reaching the oil expansion vessel.

Abstract: A fuel vapor handling apparatus supplies a purging air to a canister by using a purge pump and purges fuel desorbed from the canister into an intake pipe. A controller intermittently operates the purge so that the canister internal temperature recovers from a reduced level caused by the latent heat of vaporization of fuel during an operating period of the purge pump. Therefore, desorption of fuel from the canister during an operating period is facilitated. Since the actual operating time of the purge pump is reduced, the life of a motor that is a power unit of the purge pump becomes longer.

Abstract: A hydrocarbon adsorbent state determining apparatus is provided for compensating the ability of a hydrocarbon adsorbent to adsorb moisture for fluctuations due to a change in the flow velocity of exhaust gases to accurately determine the state of the hydrocarbon adsorbent, including a deterioration thereof, irrespective of the change in the flow rate of exhaust gases. The hydrocarbon adsorbent state determining apparatus determines the state of a hydrocarbon adsorbent disposed in an exhaust system of an internal combustion engine for adsorbing hydrocarbons and moisture within exhaust gases.

Abstract: A controller system for a molecular sieve device controls a product gas generated by n molecular sieve beds for separating a gas from an input gas supply. A valve assembly with n states has an input receiving the input gas and n outlets. Each valve state in a first position creates an open passageway from the input of the slide valve to an outlet. Transitioning a valve from the first to a second position creates a variable amount of restriction in the flow of gas between the input and a selected outlet.

Abstract: A compact and highly portable combination pressure swing adsorption apparatus and product gas conservation device for medical use, to produce efficiently a gas with a high concentration of oxygen and to deliver the oxygen concentrated gas to a user at selectable times and in selectable doses.

Abstract: There is provided a method and an apparatus for collecting a rare gas, which are capable of effectively collecting the rare gas contained in an exhaust gas exhausted from a rare gas using apparatus such as a plasma apparatus or the like, and moreover capable of securely supplying the rare gas having a predetermined purity to the rare gas using apparatus, and the method for collecting rare gas which comprises collecting a rare gas contained in an exhaust gas exhausted from a rare gas using apparatus operated under decompression, the method comprises the step of collecting the rare gas by separating the rare gas and impurities contained in the exhaust gas via at least two gas separating steps.

Abstract: A method of operating a thermal swing adsorption process by determining a parameter relating to the water content of a feed gas, selecting process conditions for regeneration of the adsorbent in the thermal swing adsorption process based on the parameter and modifying the regeneration process conditions to accord with the selected process conditions for regeneration is disclosed. Apparatus for effecting this adsorption method and apparatus in which regeneration conditions are modified based on the actual ambient water content of the feed gas are also disclosed.

Abstract: Disclosed is an air purification device with oxygen-supplying function, in which air in an automobile is sucked by a vacuum pump and purified by a dust collector or an adsorbent such as activated carbon and zeolite, and oxygen is enriched in air to supply oxygen enriched air into the automobile. The air purification device enriches oxygen in air according to a VSA (vacuum swing adsorption) process using a difference between pressure in the adsorption bed and atmospheric pressure, in which nitrogen adsorbed into the adsorbent is released using the vacuum pump. The air purification device comprises an air filter for removing impurities from air sucked from an inside of the automobile by the vacuum pump, an adsorbent for adsorbing nitrogen from air passing through the air filter and passing oxygen, an oxygen tank for storing oxygen supplied from the adsorbent and releasing oxygen using a vacuum, and if necessary, an anion generator or a scent generator.

Abstract: A system and method for passive hypoxic training provides a person with a low oxygen (hypoxic) environment. Oxygen sensors automatically monitor and control oxygen levels to maintain the altitude desired. CO2 levels are monitored and CO2 is eliminated so that the air a person breathes is substantially clean and fresh. Exposure to a high altitude environment produces physiological changes in a person's body, which becomes more efficient at absorbing and transporting oxygen. Using the present method and system, athletes obtain the benefits of sleeping at a simulated altitude in the user's own home for six to twelve hours, rather than traditional altitude therapies in which athletes spend two to three weeks at high altitude before an athletic competition to obtain similar benefits. This system allows for “live high train low” altitude training that has been shown in controlled studies to provide superior benefits to “live high train high” training.

Abstract: An air demoisturizer for an oil expansion vessel of an electrical power unit like an oil-filled transformer, tap changer or choke, has a heating element in the body of absorbent and utilizes a heat-regeneratable absorbent which is cut off by a moisture detector from the oil expansion vessel when the absorbent is saturated and is thermally regenerated. The demoisturizing column is provided in line with an oil receiver through which the dry air is passed before reaching the oil expansion vessel.

Abstract: A gas supply system including a gas cabinet defining an enclosure including therein a gas dispensing manifold and one or more adsorbent-based gas storage and dispensing vessels mounted in the enclosure and joined in gas flow communication with the gas dispensing manifold. The enclosure may be maintained under low or negative pressure conditions for enhanced safety in the event of leakage of gas from the gas storage and dispensing vessel(s) in the enclosure. The gas supply system may be coupled to a gas-consuming unit in a semiconductor manufacturing facility, e.g., an ion implanter, an etch chamber, or a chemical vapor deposition reactor.

Abstract: A gas removal filter has an ion exchanger for adsorbing a gas and at least a pair of electric resistance measuring electrodes disposed on the ion exchanger. By measuring a change in the electric resistance between at least the pair of electric resistance measuring electrodes disposed on the ion exchanger, it is possible to estimate an ion exchange group consumption ratio of the ion exchanger. The ion exchange group consumption ratio of the ion exchanger can be detected in a short period of time, and a remaining adsorption capability of the ion exchanger can be known with ease.

Abstract: A chemical filter unit 10 is made of a chemical filter 12 and a filter life detection sensor 1. The filter life detection sensor 1 is provided with an adsorption state detection sensor 3 and a reference sensor 4 to which a flow of air is blocked. The sensors 3 and 4 are made of the same filter material as the chemical filter 12 with a pair of electrodes sandwiching the filter material. An oscillation circuit, in which the sensors 3 and 4 constitute a part of the oscillating conditions, detects changes in impedance of the sensors 3 and 4 based on the changes in oscillation frequencies. A measurement of the adsorption state detection sensor 3 is corrected with a measurement of the reference sensor 4 in order to remove effects of temperature and humidity, obtain a measurement corresponding to the amount of adsorption of chemical substances, and decide on the timing of replacing the chemical filter based on the corrected measurement.

Abstract: A system and method for improving the efficiency of a gas fractionalization system of the type having a compressor having an inlet for receiving air from the ambient environment. The system includes a sensor for sensing a parameter indicative of the flow of concentrated gas delivered from the gas fractionalization system to a patient. A multi-positional valve is disposed in line with the compressor for regulating the flow of air from the ambient environment into the compressor. A valve control manipulates the position of the multi-positional valve depending on the value of the parameter sensed by the sensor for regulating the quantity of air received from the ambient environment into the compressor inlet.

Abstract: A system for drying a gas, such as air, includes a source of gas to be dried, a multistage compressor having an inlet connected to the source, and a dryer connected interstage to the compressor and to the outlet of the compressor. The dryer is connected interstage to the compressor between a compression stage and a heat exchanger of one of the compressor stages for regenerating a first desiccant filled tower. The dryer is also connected to the outlet of the compressor for drying the gas using a second desiccant filled tower. A communication structure can be activated to connect the first tower to the outlet of the compressor for drying the gas using the first tower, and to connect the second tower interstage to the compressor for regeneration of the second tower.