Abstract: A method for cooling electronic equipment. The method including propagating air through a first electronic component of the electronic equipment into a first enclosed area, where propagating the air through the first electronic component cools the first electronic component, circulating a refrigerant in a cooling loop, where the cooling loop comprises a heat exchanger, and propagating the air out of the first enclosed area by passing through the heat exchanger into a second enclosed area, where the air is cooled by passing through the heat exchanger.

Abstract: An aspirated detecting system includes a multi-channel aspirated smoke detector with each channel including an air moving element, such as a fan, first and second sets of substantially identical air flow pipes where each set defines a plurality of spaced apart inflow ports. Control circuits activate a first element and then a second element to establish a transport time associated with at least one inflow port in response to the detector sensing a predetermined smoke condition. The control circuits include a storage unit which includes pre-stored timer values which are associated with respective transport times from an associated inflow port.

Abstract: A portable oxygen generator comprises an air pump, a molecular tube and a molecular seat, the molecular tube is detachably fixed on the side wall of the molecular seat, the air pump is disposed at the lower part of the molecular seat. An air filter bucket, an oxygen storage bucket and an exhaust silencing bucket are disposed inside the molecular seat, the air filter bucket is provided with an air inlet communicated with the outside air. An air channel, an oxygen channel and an exhaust channel are disposed inside the molecular seat, the air channel is respectively communicated with the air filter bucket, the air pump and the molecular tube, the oxygen channel is respectively communicated with the molecular tube and the oxygen storage bucket, the exhaust channel is respectively communicated with the molecular tube and the exhaust silencing bucket, the air channel, the oxygen channel and the exhaust channel are respectively connected with a solenoid valve.

Abstract: A process for separating methane from a natural gas mixture employs pressure swing adsorption in one or more vessels. Each vessel has an adsorbent material having a kinetic selectivity for contaminants over methane greater than 5. Contaminants within the natural gas mixture become gases kinetically adsorbed within the adsorbent material. The vessel is placed under pressure to cause contaminants to be adsorbed in the surfaces and micro-pores of the adsorbent material. The process includes releasing a product stream comprised at least 95% by volume methane from a first gas outlet in the vessel, and desorbing the contaminant gases from the adsorbent material by reducing the pressure within the vessel. The desorbing step is done without applying heat to the vessel, thereby delivering a waste gas stream comprised at least 95% by volume of the contaminant gases. An improved fractionation vessel having both major and minor flow channels is also provided.

Abstract: A breathing apparatus is operable in self-contained and filtered modes of operation. In the self-contained mode of operation, a breathable gas is delivered to a user from a self-contained source of breathing gas. In a second, filtered mode of operation, a suction source draws ambient air through a filter removing contaminants and delivers filtered ambient air to the user. A method of delivering air to a subject is also provided.

Abstract: A temperature swing adsorption system includes a first adsorption bed configured to receive a feed stream and adsorb a contaminant from the feed stream to produce a product stream, a second adsorption bed configured to receive a portion of the product stream and a cooling stream to reduce a temperature of the second adsorption bed, a third adsorption bed configured to receive the heated product stream to increase a temperature of the third adsorption bed; a separation system to separate the cooled product stream into a first component stream and a second component stream, and a fourth adsorption bed configured to receive the first component stream and to enrich an adsorptive concentration of the first component stream. The enriched first component stream is directed to the second adsorption bed to provide the cooling stream.

Abstract: An exhausting apparatus includes an exhaust pump configured to extract unreacted precursor in a process chamber and vent the unreacted precursor out of the exhaust pump, and a first material supplier configured to supply a first material into the exhaust pump. The first material is adsorbable on an interior surface of the exhaust pump to prevent the unreacted precursor from being adsorbed on the interior surface of the exhaust pump.

Abstract: A fracking trailer includes a particulate storage enclosure to receive a mixture of particulate and air in an interior of the particulate storage enclosure having a front end and a rear end. The fracking trailer also includes a filtration system connected to the particulate storage enclosure at the front end to filter particulate from the air in the mixture and exhaust filtered air.

Abstract: A fluid separation device (400) for separating water from a stream of compressed air, has a housing (402) defining a first volume (404) with two apertures (406, 408) therein in communication with the first volume, the first volume and the apertures being adapted to have a stream of air flowing there through, a first filter (414) contained within the first volume for separating liquid water from the air stream, and a plurality of desiccant beads contained within the first volume for separating water vapor from the air. An exhaust silencer for the fluid separation device is also disclosed.

Abstract: An apparatus for purifying and neutralizing toxic gases such as odors, fumes or various volatile organic compounds generated by research laboratories, chemical processing factories or hospitals where medicinal products are handled, comprises a main body having an intake, an exhaust and a control panel; a pre-filter, a first filter, first and second neutralizing pellet beds, and a second filter which are mounted in the apparatus main body and are placed from the intake to the exhaust in that order; and a blower and a driving device placed between the first and second neutralizing pellet beds. The apparatus effectively purifies and neutralizes toxic gases and collects fine particles or dust.

Abstract: The present invention provides an air cleaning unit which contains a blower, an acid/alkaline filter device, and a particle filter device. The blower draws in outside air through the acid/alkaline filter device and produces an air flow through the particle filter device. The acid/alkaline filter device absorbs the acid/alkaline gases in the outside air. The particle filter device traps the particles in the air flow. Through this design, the blower draws in air filtered by the acid/alkaline filter device. The blower therefore does not suffer erosion and therefore the air cleaning unit enjoys prolonged operation life span.

Abstract: An air filtering apparatus includes a housing defining a top opening and having a front portion defining a bottom opening. A filter is positioned within the top opening and sealed to the housing so that air flowing into the housing passes through the filter. An expansion chamber is in fluid communication with the bottom opening. A motorized fan is located within the housing and is configured for drawing air through the filter, into the housing and out through the expansion chamber. The air output of the motorized fan is directed toward a bottom of the housing proximate a rear of the housing with the expansion chamber extending from the air output of the motorized fan to the front portion of the housing.

Abstract: A medical fluid filter system is provided comprising a housing having: a liquid trap chamber having a volume; a filter media chamber; a filter media arranged within the filter media chamber; the liquid trap chamber having a liquid trap outlet port in fluid communication with the filter media chamber; the liquid trap outlet port configured and arranged within the liquid trap chamber to inhibit flow of liquid from the liquid trap chamber to the filter media chamber and configured and arranged to allow gas to flow from the liquid trap chamber to the filter media chamber; a filter system inlet passing through the housing for intake of fluid originating from a surgical site; and a filter system outlet passing through the housing for fluid exhaust.

Abstract: The present invention provides an air cleaning unit which contains a blower, an acid/alkaline filter device, and a particle filter device. The blower draws in outside air through the acid/alkaline filter device and produces an air flow through the particle filter device. The acid/alkaline filter device absorbs the acid/alkaline gases in the outside air. The particle filter device traps the particles in the air flow. Through this design, the blower draws in air filtered by the acid/alkaline filter device. The blower therefore does not suffer erosion and therefore the air cleaning unit enjoys prolonged operation life span.

Abstract: A cyclic adsorption process is provided having pressurization and depressurization steps and driven by one or more centrifugal machines operating under acceleration and deceleration conditions wherein the deceleration rate of the machine is controlled to minimize power consumption and maximize the efficiency of the process. The operating speed of the centrifugal machine during deceleration is matched to the measured pressure ratio conditions so that the centrifugal machine arrives at its minimum operating speed near the point required to begin acceleration.

Abstract: The invention is directed to processes and apparatuses for gas treatment, in particular for the purification of methane rich gas streams, such as gas obtained from the conversion from organic matter (“biogas”). In accordance with the present invention there is provided an apparatus and a process for producing a purified methane comprising gas stream (P) from a methane containing gas stream (A), comprising the steps of: (a) pressurising said methane containing gas stream (A) and subsequently cooling it, whereby a stream comprising condensed contaminants (C) and a methane comprising stream (B) are obtained; (b) optionally feeding said methane comprising stream (B) to an adsorption unit and/or a catalytic conversion unit, whereby the concentration of contaminants in stream (B) is further decreased; and (c) cooling the methane comprising stream (B) to a temperature which is sufficient to condensate CO2 from said stream (B), whereby said purified methane comprising gas stream (P) is obtained.

Abstract: A cyclic adsorption process is provided having pressurization and depressurization steps and driven by one or more centrifugal machines operating under acceleration and deceleration conditions wherein the deceleration rate of the machine is controlled to minimize power consumption and maximize the efficiency of the process. The operating speed of the centrifugal machine during deceleration is matched to the measured ratio pressure conditions so that the centrifugal machine arrives at its minimum operating speed near the point required to begin acceleration.

Abstract: A coalescing filter device that extracts harmful particles and mist from the air. The coalescing filter device may include a housing with a coalescing filter suspended within the housing. The coalescing filter may be suspended at an angle relative to the housing, such as a 45 degree angle. A blower may be attached to the top of the housing and may blow air from the inside of the housing to the outside. A bag filter may be sealed to the top of the coalescing filter and a charcoal filter may be secured to the housing in between the blower and the bag filter.

Abstract: A feed gas drying system is described for a PSA or VPSA oxygen concentrator. A membrane dryer is inserted into the feed gas path to the concentrator absorbent beds, such that the moisture in the feed gas is directed to a part of the dryer exposed to the concentrator exhaust, thus achieving efficient operation of the membrane dryer with no loss of concentrator feed gas.

Abstract: An apparatus, system, and method are disclosed for removing ethylene from a gaseous environment. Ethylene is a gaseous growth hormone produced by plants that triggers the ripening of some flowers, fruits, vegetables, and other plants. The apparatus includes an ethylene filter and a composition. The filter includes a frame and a trapping medium. The composition is attached to the trapping medium of the ethylene filter. The ethylene filter is positioned within a gaseous environment and is configured to encounter a gas flow within the gaseous environment. The composition contains at least some titanium dioxide which is configured to attach to the ethylene as the gas flow moves through and around the ethylene filter. In this manner, some ethylene may be removed from the gaseous environment.

Abstract: A canister for trapping a fuel vapor vaporized in a fuel tank has a casing defining an adsorption chamber therein, an adsorbent capable of adsorbing the fuel vapor and filled in the adsorption chamber and a flow regulation plate disposed in the casing. The casing has a fuel introducing port configured to introduce the fuel vapor from the fuel tank into the adsorption chamber, and an air communicating port communicating the adsorption chamber with the atmosphere. The air communicating port is formed on a side surface of the casing extending in a direction of gravitational force. The flow regulation plate disposed at an end of the adsorption chamber near the air communicating port and has an opening configured to communicate the adsorption chamber with the air communicating port. The opening is positioned above the air communicating port in the direction of gravitational force.

Abstract: Apparatus and methods for reducing or eliminating undesirable air-borne substances, such as odors, bacteria, viruses, fungi, and toxins, are provided. A filter containing nanocrystalline metal oxide or metal hydroxide particles may be installed within an air handling apparatus such as an existing HVAC unit located within a building, and particularly within a home, or a portable air processor or purifier. The air handling apparatus comprises a blower which pulls air containing various undesirable substances from within the enclosed environment and directs it through a filtering device containing the nanocrystalline particles. The undesirable substances are sorbed by the nanocrystalline particles thereby creating a deodorized stream of air that may then be directed back into various portions of the enclosed environment or vented to the atmosphere.

Abstract: A chamber air scrubber a chamber with an independent air scrubbing system for configured to adsorb plant odors and emissions. The scrubber includes air scrubbers for cleaning the air. The air scrubbers include a carbon portion with active carbon that adsorbs odors and emissions. The carbon portion includes an outer and an inner cylindrical frame that retain active carbon between them. The air scrubbers also include a series of fans that forces air through the carbon portion. The fans allow the air to pass from a lower chamber to an upper chamber. The air enters through an inlet in the lower chamber before passing over a liquid chiller. The air transfers the thermal energy generated by the plants to a vent in the upper chamber. This serves to eliminate odor from the plants.

Abstract: Disclosed is a harmful material treatment system for recovering the energy and removing the harmful material in the process of treating the gas containing the harmful material generated in the multiplex utilization facility, in the display mall, in diverse manufacturing processes and in the vehicle painting process, more particularly, to a harmful material treatment system which can recover the energy contained in the air conditioning facility or in the exhaust gas of the process with an efficiency of more than 90%, for exhausting the inside air to the outside so as to treat the contaminating material such as odor and volatile organic chemicals, and to remove the harmful material with a removal efficiency of more than 90% by adsorbing and concentrating the harmful material with a rotary-type adsorbent.

Abstract: A system for collecting an anaesthetic agent, having at least one anaesthetic gas scavenging system (AGSS) for receiving exhaust gas from a plurality of sources, the exhaust gas including the anaesthetic agent to be collected, each AGSS comprising at least one power source for providing suction of the exhaust gas from the plurality of sources under negative pressure, and a central collection system for receiving the exhaust gas, the central collection system comprising at least one collector for collecting the anaesthetic agent from the exhaust gas, wherein the at least one collector is configured to adsorb the anaesthetic agent from the exhaust gas. The central collection system may be configured to received the exhaust gases from the at least one AGSS, with the central collection system being located downstream of the at least one AGSS.

Abstract: The present invention includes: LCDs (47, 48, 49) corresponding to red, green, and blue, respectively; an air duct for red, an air duct for green, and an air duct for blue provided to blow cooling air to the LCDs (47, 48, 49), respectively; air filters (43, 50) provided in each of the air duct for red, the air duct for green, and the air duct for blue; and air filters (41, 42) provided in at least one air duct of the air duct for green and the air duct for blue and having filter mesh size smaller than that of the air filters (43, 50).

Abstract: An apparatus, system, and method are disclosed for removing ethylene from a gaseous environment. Ethylene is a gaseous growth hormone produced by plants that triggers the ripening of some flowers, fruits, vegetables, and other plants. The apparatus includes an ethylene filter and a composition. The filter includes a frame and a trapping medium. The composition is attached to the trapping medium of the ethylene filter. The ethylene filter is positioned within a gaseous environment and is configured to encounter a gas flow within the gaseous environment. The composition contains at least some titanium dioxide which is configured to attach to the ethylene as the gas flow moves through and around the ethylene filter. In this manner, some ethylene may be removed from the gaseous environment.

Abstract: A method and arrangement for removing solid particles and tar component from carbon monoxide gas. In the method, carbon monoxide gas is conducted from a ferroalloy smelting furnace (1) to a gas scrubber (2), the carbon monoxide gas is scrubbed in the gas scrubber (2) by a liquid medium for removing part of the solid particles, the carbon monoxide gas is conducted from the gas scrubber to a blower (3), the flow rate of the carbon monoxide gas is increased by the blower (3), and the carbon monoxide gas is conducted to a particulate filter (5) and the remaining solid particles are essentially filtered in the particulate filter (5) from the carbon monoxide gas.

Abstract: A portable gas fractionalization apparatus that provides oxygen rich air to patients is provided. The apparatus is compact, lightweight, and low-noise. The components are assembled in a housing that is divided into two compartments. One compartment is maintained at a lower temperature than the other compartment. The lower temperature compartment is configured for mounting components that can be damaged by heat. The higher temperature compartment is configured for mounting heat generating components. An air stream is directed to flow from an ambient air inlet to an air outlet constantly so that there is always a fresh source of cooling air. The apparatus utilizes a PSA unit to produce an oxygen enriched product. The PSA unit incorporates a novel compressor system which includes the use of free piston linear compressors so as to reduce power consumption, noise and vibration reduction.

Abstract: An apparatus and a method for separating a specified gas from a gas to be treated containing the specified gas comprising at least one ingredient, which comprises allowing the gas to be treated to flow through a column without the use of another gas for transferring the gas to be treated, while keeping the inside of the column packed with a packing material at a reduced pressure. The above apparatus and method can be suitably used for separating a specified gas having a high purity at a low cost.

Abstract: A feed gas drying system is described for a PSA or VPSA oxygen concentrator. A membrane dryer is inserted into the feed gas path to the concentrator absorbent beds, such that the moisture in the feed gas is directed to a part of the dryer exposed to the concentrator exhaust, thus achieving efficient operation of the membrane dryer with no loss of concentrator feed gas.

Abstract: The invention relates to an air cleaner, and more particularly to an air cleaner which includes a regenerative deodorizing filter to purify and treat gaseous substances contained in air, thus enabling efficient regeneration of the regenerative deodorizing filter, and a method of regenerating the filter of the air cleaner.

Abstract: A combined air-supplying/air-purifying breathing system that includes a self-contained breathing apparatus, a facepiece for delivering breathable air from the self-contained breathing apparatus to a user, and a powered air-purifying respirator having at least one filter and a blower and having an output connected by a hose assembly to the facepiece. A control interface operationally connects the self-contained breathing apparatus to the powered air-purifying respirator. The self-contained breathing apparatus includes a pressure vessel, a cylinder valve assembly and a pressure reducer, all carried by a back frame, and the powered air-purifying respirator is adapted to be mounted on, and carried by, the back frame, by coupling the back frame and the respirator together at respective attachment points.

Abstract: A vehicle air dryer comprising: a dryer cylinder for drying compressed air passing therethrough, an exhaust assembly for providing an additional air outlet, a backflow assembly for providing a backflow air passage, an air pressure governor assembly for maintaining air pressure inside the vehicle air dryer, an one way check valve for providing one way air passage for dried compressed air and preventing air leakage, and a dryer valve body having an air inlet, an air inlet chamber, an air outlet, a slanting air passage leading to the air outlet, a first opening for installing the exhaust assembly, an opposite, second opening for threadingly attaching the dryer cylinder, a third opening, substantially perpendicular to the second opening, for mounting the backflow assembly, and a fourth opening, substantially parallel to the third opening, for receiving the air pressure governor assembly.

Abstract: A powered air-purifying respirator that includes an enclosure, defining a single contiguous enclosed interior, an inlet duct, including an inlet and a distribution portion, that guides ambient air to the interior of the enclosure, a plurality of filter canisters disposed within the interior of the enclosure, and a blower that forces air through the at least one inlet, into the interior of the enclosure and through the plurality of filter canisters to produce filtered air suitable for breathing. A valve controls the flow of ambient air through the inlet duct. A fluid dam, disposed in an air path between the inlet and the filter canisters prevents liquids from reaching the filter canisters. The enclosure is reinforced and is adapted to provide protection for the filter canister from flame and heat while the filter canister is in use. A recirculation valve recycles previously-filtered air back into the enclosure.

Abstract: A breathing apparatus is operable in self-contained and filtered modes of operation. In the self-contained mode of operation, a breathable gas is delivered to a user from a self-contained source of breathing gas. In a second, filtered mode of operation, a suction source draws ambient air through a filter removing contaminants and delivers filtered ambient air to the user. A method of delivering air to a subject is also provided.

Abstract: The invention relates to a method with associated device for the removal of fine particulates from the air in open areas and includes the phases of suction intake, filtering and re-emission into the atmosphere of the air taken from the environment at a height near the ground. The device also provides for the cleaning of the filtering equipment and for the discharge of the washing sludge for subsequent disposal.

Abstract: A filter arrangement for cleaning fuel cell supply air, including at least two filter layers, whereby a first filter layer is designed as a coarse filter and a second filter layer as a fine filter, wherein the second filter layer includes an electret filter material.

Abstract: A filtering method and a filter device (10) for removing impurities from the breathing air (24) in a room, an air raid shelter or a vehicle. According to the filtering method, the air to be filtered is driven through a carbon dioxide filter (13) by a fan (15), with the result that at least a portion of the carbon dioxide and/or mold spores and other impurities in the air are trapped in the carbon dioxide filter. After the filtering, the filter is regenerated and the carbon dioxide and/or mold spores trapped in it are removed by a technique whereby air heated by a thermal resistor (20) is passed through the filter, this air preferably consisting of the same air to be filtered.

Abstract: Disclosed is a method and a filter unit for depleting or enriching a liquid or gas with substance(s) comprising i) providing a filter unit comprising at least one convective layer and at least one receiving layer adjacent one another, ii) passing the liquid or gas through the filter so that the main direction of flow is along the layers and the main flow of liquid gas is in the convective layer, allowing the substance(s) to: a) be transferred from a convective layer to a receiving layer, and b) be retained or otherwise modified or transferred within a receiving layer, or c) be provided by the receiving layer, and d) be transferred from the receiving layer to the fluid in the convective layer.

Abstract: An air purification system including a Particle Phase Pollutant (PPP) treatment section (9) having an air inlet (14) and an air outlet (15), a particle removal filter, (11) and a blower (12) to draw air from the air inlet (14) of the PPP treatment section (9) to pass through the particle removal filter (11) and exit through the air outlet (15) of the PPP treatment section (9). The system also includes a Gas Phase Pollutant (GPP) treatment section (10) installed at a downstream position of the particle removal filter (11) of the PPP treatment section (9), the GPP treatment section (10) having an air inlet (19) and an air outlet (20), a gas removal filter (16) with high filter air flow resistance, and a blower (17) located at a downstream position of the gas removal filter (16) to draw air from the air inlet (19) of the GPP treatment section (10) to pass through the gas removal filter (16) and exit through the air outlet (20) of the GPP treatment section (10).

Abstract: A coating machine is provided with an exhaust processor. The exhaust processor includes a collator and a pumping and filtering unit. The collector includes a conduit disposed therein, a drawer movable therein under the funnel and at least one vent defined therein. A lower end of the funnel extends into the drawer so that when exhaust goes into the drawer from the conduit, a major portion of paint carried in the exhaust deposits in the drawer. The pumping and filtering unit includes a filter, at least one pipe and a pump. The pipe connects the filter to the vent. The pump pumps the exhaust to the environment from the coating chamber through the exhaust processor.

Abstract: A filter cleaning system according to one aspect of the invention comprises a baghouse including a tubesheet having a plurality of openings extending therethrough. A plurality of filter cartridges is sealingly mounted to the tubesheet at respective openings. Each filter cartridge has an open end and pleated media for filtering particulates from gas flowing therethrough. The filter cartridge has particulates accumulate on the pleated media. A pulse cleaning system intermittently directs cleaning pulses of air into the open ends of the filter cartridges media at a supply pressure in the range of about 20 PSI to 60 PSI to dislodge accumulated particulates from the pleated media.

Abstract: A device for conditioning recirculating air in a cleanroom has at least one fan having a housing. A return air conduit is provided through which a first portion of recirculating air is supplied from the cleanroom to the at least one fan. A second portion of the recirculating air is directly supplied to the at least one fan by bypassing the at least one return air conduit.

Abstract: A filter assembly for use in a disk drive assembly is disclosed. The filter assembly is configured to remove contaminants within the drive assembly and to prevent entry of contaminants into the drive assembly. In one implementation the filter assembly includes a housing configured for placement in a disk drive assembly containing a rotating disk, the housing including an air scoop having an entrance configured for placement beneath the rotating disk in the drive assembly; and a major surface having a wall and an opening in the wall, the opening configured for receiving a filter material and being in fluid communication with the entrance to the air scoop. A filter element is positioned within the housing and configured so that a first portion of the element filters air directed from the air scoop, while a second portion of the element filters air from the exterior of the drive assembly, the first and second portions sealed by a common filter material placed over the opening in the major surface.

Abstract: An apparatus and process for abating at least one acid or hydride gas component or by-product thereof, from an effluent stream deriving from a semiconductor manufacturing process, comprising, a first sorbent bed material having a high capacity sorbent affinity for the acid or hydride gas component, a second and discreet sorbent bed material having a high capture rate sorbent affinity for the same gas component, and a flow path joining the process in gas flow communication with the sorbent bed materials such that effluent is flowed through the sorbent beds, to reduce the acid or hydride gas component. The first sorbent bed material preferably comprises basic copper carbonate and the second sorbent bed preferably comprises at least one of, CuO, AgO, CoO, CO3O4, ZnO, MnO2 and mixtures thereof.

Abstract: A combined building air-conditioning unit and NBC protection system, containing an enclosed space housing a building air-conditioning unit and further including a plurality of chambers, a first chamber having an ambient air inlet port, one prefilter and a blower for sucking air through the prefilter, a second chamber having a valve including an open and closed state, receiving air from the blower and accommodating a C-detector and a valve actuator responsible, at least indirectly to, and operable by, the C-detector, and a third chamber housing at least one C-filter and a blower for sucking air from the second chamber via the C-filter into the building when the valve is in its closed state. A method for economically controlling air purity within a protected space is also provided.

Abstract: An apparatus and method for abating toxic and/or hazardous gas species in a diluent gas stream line deriving from a by-pass line of a semiconductor process tool, comprising contacting the diluent gas stream with a dry resin sorbent material having an affinity for the toxic and/or hazardous gas species to effect the removal of at least a portion of the toxic and/or hazardous gas species by a chemisorbent or physisorbent reaction between the sorbent bed and the toxic gas component effectively reduces the concentration of the toxic gas component in the process diluent stream to below TLV.

Abstract: In a fan filter unit for filtering and continuously supplying clean air into a clean room, the fan filter unit includes a chemical filter for removing chemical contaminants contained in the air, a fan for sucking and blowing out the air, and a particle filter for removing particles such as dusts and moisture contained in the air. A filter medium of the chemical filter has a circular tube shape and is disposed between an inner circular tube and an outer circular tube. A cover is detachably combined with top portions of the inner and the outer circular tubes, and prevents air flow through the top portions of the inner and outer circular tubes. The air is sucked only through the outer circular tube, the chemical filter and the inner circular tube by a suction force of the fan. Accordingly, velocity distribution of the air passing through the chemical filter may be improved and lifetime of the chemical filter may be increased.

Abstract: A powered air purifying respirator (PAPR) assembly and kit therefore has an elongated hollow belt body having open first and second ends and multiple inlet openings along its length for mounting one or more filter canisters, one or more filter canisters for mounting in the inlet openings for supplying purified air to the interior of the belt body, a motor and driven fan assembly having a fan inlet in communication with each filter canister through the hollow belt body and a fan outlet; and a power source operably mounted to the belt body and connected to the motor. The PAPR assembly forms a portion of a belt or bandolier to be worn around the user's waist, back, or other location, and at least the belt body can be made of a flexible rubber material, such as a Butyl and Silicone blend, or any other suitable material to conform the PAPR belt to the user's body.