Abstract: An end-of-service-life-indicator for a multi-agent respirator filter that is safe, reliable, and easy to read and may be configured to cover a broad range of threats, including chemical warfare agents and toxic industrial chemicals, is achieved by positioning an array of chemically reactive calorimetric indicators substantially next to a sorbent bed behind a viewing window that may be integrated into the filter housing. Each colorimetric indicator in the array may be configured to produce a color change in responsive to a different target threat or threat category and may be calibrated to display easily identifiable colors, symbols or patterns to indicate an optimum time to exchange a filter.

Abstract: The removable apparatus of a transparent filterable dust bag with a support container is designed as an attachment for a vacuum cleaner and like. A transparent filterable dust bag having an outer transparent wall and an inner filter cone coincides within a transparent support container which keeping the shape and position of the dust bag while separating dust from air. The transparent support container and the outer transparent wall of the dust bag allow to watch inside the filling level of the dust bag and to replace properly.

Abstract: A portable, self-contained air-purifying device that enables a person standing outside the device to use his hands to manipulate objects within the device so that those objects can be kept in particulate-free environment while being manipulated. The device includes a housing having a sealable opening, an airflow-generating device that circulates the air within the housing, an air filter, and manipulation structure configured to enable a person located outside said housing to use their hands to grasp and manipulate objects which have been placed within the chamber that has been subsequently sealed.

Abstract: A multi-cyclone dust separating apparatus includes a cyclone unit and a separable filter assembly adapted to be disposed at least partially in a discharge path of the cyclone unit. The cyclone unit includes a main cyclone, a secondary cyclone adapted to be disposed at substantially a same plane as the main cyclone, and a dust collecting casing adapted to substantially surround the main cyclone and the secondary cyclone. The dust collecting casing includes a dust chamber to collect dust separated at the main cyclone and the secondary cyclone.

Abstract: The present invention provides a tractor in which necessity of maintenance of a precleaner can be checked without opening a bonnet every time. In a tractor in which the outside air which is purified through a precleaner is further purified through an air cleaner before the outside air is supplied to an engine, a radiator is arranged in front of the engine, the precleaner is arranged in front of the radiator, and the engine, the radiator and the precleaner are covered with a bonnet, the precleaner is arranged such that the interior of at least a dust collecting/storing portion of the precleaner is viewable from the outside in a see-through manner, and the bonnet includes a viewing portion through which the interior of the dust collecting/storing section is viewable.

Abstract: A quick-change filter system including at least one base, and at least one quick-change filter having an inlet, an outlet, and a filter housing. The base includes a filter coupling part having a gas inlet stub for connection to the inlet, and a gas outlet stub for connection to the outlet. The filter housing is at least partly filled with filter material, and is connected to the inlet and the outlet. The quick-change filter further includes quick-change coupling containing the inlet and the outlet of the quick-change filter and arranged for cooperation with the filter coupling part. The base is configured for manual connection to the quick-change filter, and for automatic, gastight sealing of the gas outlet stub and the gas inlet stub when decoupling the quick-change filter from the base.

Abstract: The invention relates to a separation assembly for separating dirt and dust from air in a vacuum cleaner (1), through which assembly an air flow path extends from an inlet (5) to an outlet (6). The air flow path extends through an upstream separator (18) and a downstream separator (19). The downstream separator (19) includes an air-permeable filter element (28) bounding an inner space (27). The wall sections bounding the air flow path in the area of the downstream separator include at least a transparent section (30) through which the filter element (28) is visible. The inner space (27) is located upstream of an area (31) outside the filter element (28) for filtering air flowing from inside the filter element (28) to outside the filter element (28).

Abstract: A transparent foldable dust bag is designed as an attachment for a vacuum cleaner and like. The transparent foldable dust bag has a foldable outer transparent wall portion and a foldable inner filter cone portion connected by the top connector and the bottom flange to form a hollow cavity for separating and collecting dirt and dust from air. Opened dust bag is deployed and stretched by the rigid top connector and bottom flange for keeping the shape of the dust bag in a designed position. See through the outer transparent wall of the dust bag allows to look filling level inside of the dust bag and to replace it properly without exposing collected dust and dirt.

Abstract: An apparatus for filtering and containing grease or other effluent discharged from a drain spout of an exhaust fan includes a hollow housing and top and bottom portions covering each end thereof. A filter element disposed within the housing for filtering the effluent. A first aperture is provided in a top portion for enabling entry of the effluent into the housing and a plurality of second apertures is provided in a bottom portion for enabling passage of a filtered effluent. An apparatus is adapted for attachment to a roof surface or to a duct housing attached to the exhaust fan. The housing may include a transparent portion for visually identifying the saturation magnitude of the filter element.

Abstract: A securing device for a filter element, which can be detachably mounted on an extractor hood, has a connecting implement for detachably connecting the filter element to the associated extractor hood. The connecting implement catches the filter element when detaching the filter element from the extractor hood and prevents it from falling down. The connecting implement has a fixing element with a rod-like section and with a thickening connected thereto. The connecting implement also has a closure element with a U-shaped slot. The rod-like section of the fixing element is formed so that it fits the U-shaped slot of the closure element.

Abstract: A fluid filter is provided with a snap-together housing for the filter media. The housing is designed with two main parts that are easily snapped together to encapsulate the filter media. The filter housing is substantially cylindrical, and contains an inlet on one end of the filter and an outlet on the opposing end. The filter can be designed so as to be opened for the replacement of the filter media.

Abstract: There is disclosed a vacuum cleaner including a dust separation section which separates air and dust flowing toward an intake port of a motor blower through a connection port of a cleaner main body. The dust separation section includes an air path forming member which performs a separation function. The forming member includes an introductory port, a derivative port, and an opening disposed between these. In the separation function, while dust-containing air flows toward the derivative port from the introductory port, a part of the air is sucked by the motor blower through the opening. Accordingly, the air is separated from the dust which goes straight in the air path forming member with inertia.

Abstract: The invention is floor care appliance such as vacuum cleaner having two embodiments of a dirt particle separating and collecting system removably inserted into a recess in the floor care appliance's housing. One embodiment of the dirt particle separating and collecting system includes a translucent dirt cup having an apertured between two adjacent dirt particle collecting chambers and a primary filter located in one of the chambers. The other embodiment is a translucent bag container and a filtration bag. The filtration bag may or may not be disposable and may or may not have a HEPA rating. When either embodiment of the dirt particle separating and collecting system is installed in the housing, a portion of the dirt particle separating and collecting system is not visible in the area in the front of the floor care appliance. Another portion of the dirt particle separating and collecting system is visible in the area in the front of the floor care appliance.

Abstract: A dust collecting container for a vacuum cleaner is removably mounted in a suction chamber of a cleaner body to filter a dust from a dust-laden air being drawn into the suction chamber through an air suction hole that is connected with the outside. The dust collecting container has a dust collecting casing having a connecting hole connected with the air suction hole and a discharge portion for discharging the drawn air, and a filter assembly having at least three filters, and removably mounted at the discharge portion. With the plurality of filters that respectively and consecutively filter from the largest to the most minute particles of the dust-laden air drawn in the dust collecting chamber, the dust collecting container is rarely blocked even for a long period of use.

Abstract: A separator tank assembly comprising a cast hollow tank and a cast lid. The cast hollow tank has a closed end and an open end having a first opening and a second opening. The cast lid has a first passage configured for fluid communication with the tank first opening and a second passage configured for sealed fluid communication with the second opening. The first passage is formed with an integral port configured to receive a pressure control valve and the second passage is formed with an integral port configured to receive an oil filter and wherein the tank is configured such that air having undergone primary separation flows through the first opening and oil within the tank flows through the second opening.

Abstract: Disclosed is a cyclone separating apparatus, and a vacuum cleaner having the same. The cyclone separating apparatus includes a first cyclone separating dust from dust-ladened air. A plurality of second cyclones centrifugally separate fine dust particles from air which is first separated at the first cyclone. A dust collecting unit detachably connects to the first and the second cyclones. The dust collecting unit separately collects large dust particles separated at the first cyclone, and fine dust particles separated at the second cyclone. Accordingly, a more compact cyclone separating apparatus can be realized with improved suction efficiency and dust collecting efficiency.

Abstract: A novel sanitary and odor free workstation having two spaced apart, transparent plate members that are operatively interconnected to a vacuum source and in combination define a vacuumed air evacuation area that functions as a workstation between the plate members. Thus, a user can easily position an object of choice within the workstation, or even adjacent thereto, and have hands free controlled access that allows manipulation of the object yet protects the user, and others, from physical or airborne transference of bacterial matter and from any undesirable odors emitting there from and also protects the user's eyes from any potential damage, respectively. Furthermore, the workstation is portable, self-contained, safe, sanitary and is substantially usable with any object of choice.

Abstract: A universal pan or pot lid is disclosed, absorbing and filtering steam and smell with the optional aid of a sucking fan. This lid preferably of transparent material is provided with a filter changing color when it is saturated and arranged in a burn proof ergonomic knob that can be detached from the lid flat allowing an easy cleaning and washing of all its components.

Abstract: An end of service life indicator (ESLI) device for a fluid filter is included on the filter and visually indicates when the life of the filter has expired. The ESLI indicates the depletion of the filter by changing the color density on a surface of the device to a color density having a well distinguishable contrasting pattern that is easily recognizable even by individuals who are color-blind. The contrasting pattern may express text indicative of the state of the filter.

Abstract: A fluid filter is provided with a snap-together housing for the filter media. The housing is designed with two main parts that are easily snapped together to encapsulate the filter media. The filter housing is substantially cylindrical, and contains an inlet on one end of the filter and an outlet on the opposing end. The filter can be designed so as to be opened for the replacement of the filter media.

Abstract: A collecting device for collecting particles floating in the atmosphere includes a collecting container; a pump for sucking the atmosphere into the collecting container; a discharge electrode disposed in the collecting container for generating single polarity ions to charge the particles in the collecting container; and a dust-collecting electrode for collecting the charged particles in the collecting container through a potential difference between the discharge electrode and the dust-collecting electrode. The dust on the dust-collecting electrode is measured and analyzed.

Abstract: A quick-change filter system provided with at least one base and at least one quick-change filter, which base is provided with a filter coupling provided with a gas inlet stub for connection to an inlet of the filter and with a gas outlet stub for connection to an outlet of the filter, the filter being provided with a housing, which is at least partly filled with filter material and to which the inlet and the outlet are connected, and with a quick-change coupling arranged for cooperation with the filter coupling of the base, the coupling containing the inlet and the outlet of the filter, the base being provided with a mechanism for manually connecting the filter to the base, and being provided with a sealing mechanism for automatic, gastight sealing of the gas outlet stub and the gas inlet stub when decoupling the filter from the base.

Abstract: Methods and apparatus for removing sediment from a liquid are provided. Pulses of pressurized air are directed into a conduit having an inlet disposed within a first liquid-containing vessel adjacent to (or within) the sediment to cause a slurry of liquid and sediment to flow through the conduit into a second vessel elevated above the first vessel. The slurry of liquid and sediment is allowed to drain from the second vessel into a third vessel that is positioned at an elevation lower than the second vessel. Liquid is drained from the third vessel (to another vessel or elsewhere) as sediment accumulates within the third vessel. The third vessel may be removed when accumulation of sediment therewithin reaches a predetermined amount. The accumulated sediment within the third vessel is removed and the third vessel is returned to service, or another empty vessel may be substituted therefor.

Abstract: A deodorizer mounting for engagement into a wall-mounted electrical outlet box including an adsorber unit for removing gases and odors from the ambient atmosphere, a generally L-shaped bracket including a horizontal leg and a vertical leg, a cover plate having a front side and a rear side, at least one prong, mounted to and extending perpendicularly from the rear side of the cover plate, sized and spaced to engage the female receptacle of the electrical outlet box, and a means to affix the front side of the cover plate to the vertical leg of the L-shaped bracket. A mounting device and method of installation obviates or at least reduces the poor aesthetics of conventional wall-mounted adhesive units and the relatively high replacement costs for non-securable room deodorizers.

Abstract: A collecting device for collecting suspended particles includes a mobility analysis device; a collecting container connected to an outlet of the mobility analysis device; a discharge electrode disposed inside the collecting container for charging the particles inside the collecting container by generating single polar ions; and a collecting electrode for collecting the charged particles inside the collecting container by an electric potential difference relative to the discharge electrode. In the mobility analysis device, the particles are charged and guided into a flow path. An electric field is created in the flow path, and the particles are guided into the path perpendicular to the electric field. Since a mobility of a particle in an electric field depends on a size of the particle, the particles guided in the path are separated according to the electric field, thereby obtaining particles with sizes in a specific range.

Abstract: Filter media and filter structure or media pack can be engineered to exhibit high initial efficiency and to surface load particulate removed from a gaseous stream. The filter technology protects engine operation from ingested particulate and accumulates the particulate as a surface loaded layer visible on the surface of the structure. The particulate accumulates as a surface loaded layer until it achieves a certain depth of particulate or gray scale characteristic or color depth indicative of the end of the useful life of the filter prompting a change of the filter structure. The filter structure is characterized by its ability to surface load particulate, avoid accumulation of particulate in the depth media and enhance the characteristics of the material through surface loading. Such technology is particularly useful in light duty vehicle maintenance technology.

Abstract: The disclosure is directed to a cyclone dust collector for separating air from dusts by way of a centrifugal force and, more particularly, to a novel canister type vacuum cleaner capable of using a dual cyclone dust collector with maximized allowable dust capacity. The entire structure of the vacuum cleaner as suggested herein is configured for the user's simple manipulation in discarding various foreign matters collected in the vacuum cleaner, thereby improving reliability to the user.

Abstract: The liquid separator with integral sight glass separates liquids, if present, from gases and allows a technician to visually confirm the presence or absence of liquids in the gas. The present invention is typically used when taking a spot sample from a natural gas pipeline. Spot samples of natural gas are often analyzed by gas chromatographs which do not tolerate the presence of liquids in a sample. If the technician visually confirms the presence of liquids, adjustments to the spot sampling technique can be made to possibly eliminate the creation of such liquids due to poor technique.

Abstract: A universal drum lid for vacuum systems includes an inlet port configured to intercept downwardly flowing influent at a baffle and engage a direction plate which redirects the flow laterally against an adjacent side wall of the receptacle. An outlet port is shielded by the direction plate. Maximum liquid removal and minimal liquid carryover is achieved through the use of the drum lid. Preferably, a disengagement chamber precedes the baffle for disengaging suspended particles, including liquid, and permitting debris to pass the baffle without blockage. A single float ball-valve is sensitive to flow and will seal the outlet on high liquid entrainment and on high liquid levels.

Abstract: A fluid filtration system, such as an ambient air cleaner, employs a measurement mechanism to determine the amount of fluid flow through the system. The measurement system provides data or actuates an indicator. The indicator may have a pointer to indicate fluid flow along a gradient display that contains numeric information and/or is color coded. Alternatively, fluid flow may be displayed electronically. The indicator may be protected within a separate housing that projects from a filtration unit housing or may be disposed within a recess of the filtration unit housing.

Abstract: The liquid separator with integral sight glass separates liquids, if present, from gases and allows a technician to visually confirm the presence or absence of liquids in the gas. The present invention is typically used when taking a spot sample from a natural gas pipeline. Spot samples of natural gas are often analyzed by gas chromatographs which do not tolerate the presence of liquids in a sample. If the technician visually confirms the presence of liquids, adjustments to the spot sampling technique can be made to possibly eliminate the creation of such liquids due to poor technique.

Abstract: A filter soil detecting device includes a chamber provided in communication with an air channel at an air inflow side or outflow side of a filter provided in a pneumatic device. The chamber has a lens and a diaphragm to move toward or away from the lens by pneumatic pressure. The diaphragm has a mark on the surface opposite to the lens. The diaphragm moves toward or away from the lens by pressure variation at the air inflow side or outflow side of the filter, so that the image of the mark seen from the outside of the lens is varied to allow the determination of degree of soiling of the filter.

Abstract: A disposable filter for filtering exhaled gas in a breathing apparatus has a housing with an inlet and an outlet and a filter unit disposed in the housing. To increase the efficiency of the disposable filter a water trap is integrated with the housing, with water that condenses in the filter unit being collected in the water trap.

Abstract: A trap apparatus includes a discharge path for evacuating a hermetically sealed chamber through a vacuum pump, a hermetically sealed trap container extended across the discharge path and a regeneration path disposed adjacent to the discharge path, a trap unit disposed in the trap container for attaching a product in a discharged gas thereon and removing the product form the discharged gas, the trap unit being selectively located at the discharge path or the regeneration path, a valve element disposed on both sides of the trap unit and being movable integrally with the trap unit, and a sealing material mounted on an outer circumferential surface of the valve element so as to slide over an inner circumferential surface of the trap container when the trap unit is moved.

Abstract: A method of accessing and cleaning an interior portion of a gas scrubber canister in-situ. A removable glass member is attachable to a flange formed on the canister. By removing the removable glass member an access port in communication with the interior portion of the canister is provided. A vacuum device is insertable through the access port to clean the interior portion in-situ.

Abstract: An air filtration device for intake of atmospheric air, removal of contaminants from the atmospheric air, expulsion of filtered air, includes a housing configured for application directly to an electrical outlet and provides air intake from the front surface of the housing and air expulsion from the side of the housing to utilize a wall surface to disperse the filtered air. A filter change indicator is provided to communicate that a filter should be changed, and a filter orientation system is provided to allow proper orientation of the filter with respect to air flow.

Abstract: A rotationally adjustable respirator cartridge having a self-contained end of service life indicator adjacent the interior of a sidewall of the cartridge shell and in contact with the filter medium provides a color-changing display field that is visible to the wearer of the respirator through a transparent portion of the sidewall. A display window is defined by an opaque border area that surrounds the sensor display field and obscures a predetermined portion of the downstream end of the indicator to provide a desired margin of safety to the wearer. In order to permit the wearer to rotationally position the color-changing display field in the line of sight through the transparent portion of the respirator facepiece, the cartridge is provided with a rotatable mounting assembly that is continuously rotatable in one direction and that forms a seal with the cartridge shell.

Abstract: An air purifier including a housing supporting an air inlet, an air outlet and an air flow passage interconnecting the air inlet and the air outlet. The airflow passage is defined by a filtration chamber positioned upstream from a blower chamber and an ultraviolet light chamber. A blower assembly is supported within the blower chamber and includes a fan driven by a motor for forcing air through the air flow passage from the air inlet to the air outlet. A pre-filter and a main filter are removably supported within the air filtration chamber for entrapping particulates having a size of 0.3 microns and greater. An ultraviolet light source is positioned within the light chamber and is positioned proximate the air outlet. An outlet grille is supported proximate the air outlet and provides for the passage of air while substantially preventing the passage of ultraviolet light. The outlet grille includes a louver assembly including a plurality of blades defining a plurality of convoluted passages.

Abstract: A dust bag is designed for use in the vacuum cleaner and comprises a bag body of a hollow cylindrical construction. The bag body is provided in the interior with a dust-receiving space, and in one end with a dust admitting port in communication with a dust discharging port of the vacuum cleaner. The bag body is provided in the wall of the upper portion with a see-through window via which one can easily see if the dust-receiving space is fully loaded with dust.

Abstract: An air treatment appliance having an external body at least partially constructed of a translucent material. An air inlet and an air outlet in the external body permit airflow through the device. A fan inside the body is operable to draw in air through the air inlet and to expel it through the air outlet and the air may be passed through a filter mechanism in the device. At least some components of the interior of the air treatment appliance having a condition capable of visibly changing during an operation of the appliance, such as the filter mechanism and the fan, are visible from the exterior through the translucent material of the external body such that the condition is visible from the exterior of the external body through the translucent material. The translucent material may be clear, colored, or a predetermined combination of colors.

Abstract: A sight flow indicator having a viewing window for monitoring liquid flowing therethrough is disclosed. The flow indicator is configured to disentrain gas and particulate from a portion of the fluid. The flow indicator is also configured to reduce the velocity of fluid flowing therethrough. The portion of the fluid from which gas and particulate has been disentrained is diverted from the main flow stream, past the viewing window. The relatively clean liquid sample flowing past the viewing window lends itself to relatively accurate optical analysis using, compared to the bulk fluid flowing through the flow indicator. The flow indicator is well-suited for use with a spectrometer or other optical analyzer.

Abstract: A system is provided for de-gassing a material. The system includes a vessel and a material distributor. The vessel has an internal chamber in which a vacuum can be maintained. The material distributor is located inside the internal chamber and is adapted to distribute the material to be degassed as a thin film along at least one wall of the vessel in such a way that exposure of the thin film to vacuum within the internal chamber causes entrained air or other gasses from the material to be withdrawn from the thin film. Also provided is a method for degassing a material. Preferably, a material distributor is inserted into a vessel where degassing of a material is to be performed. The material distributor can comprise an inlet for the material to be degassed, a scaling lip, a film-forming lip, and a material distribution cavity. The sealing lip is adapted to sealingly engage at least one wall of the vessel. The film-forming lip is spaced apart from the sealing lip.

Abstract: An air filtration device for intake of atmospheric air, removal of contaminants from the atmospheric air, expulsion of filtered air, includes a housing configured for application directly to an electrical outlet and provides air intake from the front surface of the housing and air expulsion from the side of the housing to utilize a wall surface to disperse the filtered air. A filter change indicator is provided to communicate that a filter should be changed, and a filter orientation system is provided to allow proper orientation of the filter with respect to air flow.

Abstract: A filtering, water eliminating and lubricating compressed air valve structure includes a compact air valve installed between a conventional air compressor and a pneumatic tool. A filter element is positioned inside the air inlet fitting of the compact air valve and, after a transparent condensate chamber is installed over the air inlet fitting, a washer mount and a filter ring are inserted over the bottom of a cross-shaped annular connector, at the bottom of which is a hollow neck that is in continuity with its tubular circumferential wall. A plurality of passages in the lower circumferential end of the hollow neck are disposed in continuity with a throat at the top and a threaded hole, enabling the installation of an lubricating oil reservoir on the upper half of the cross-shaped annular connector.

Abstract: A transparent molded plastic lid for use on an auxiliary trash collection container used with a shop vacuum cleaner or dust collector system that permits inspection of the container contents without removal of the lid.

Abstract: An evacuation system is provided for removing smoke generated during a surgical procedure performed in a surgical room. The evacuation system includes a pre-filter assembly and a replaceable filter cartridge module disposed in the surgical room to permit replacement of used filter cartridge modules with new filter cartridge modules by personnel within the surgical room. A vacuum generator is disposed outside of the surgical room and includes a vacuum pump for establishing an air flow through the replaceable filter cartridge module. The pre-filter assembly includes an elongate flexible suction hose that is adapted for manipulation into position adjacent the medical procedure. A mechanical connection mechanism enables pre-filter assemblies to be easily replaced between each surgical procedure. An accumulated filter usage circuit calculates a quantity of filter capacity available and generates a filter loading signal based on the available capacity.

Abstract: The trap apparatus of the present invention includes a case provided for a gas exhaust system used for a film forming equipment which carries out a film forming process on an object, a gas supply port, made in the case and connected to an exhaust pipe of the gas exhaust system, for introducing an exhaust gas flowing through the exhaust pipe, into the case, a gas exhaust port, made in the case and connected to an exhaust pipe of the gas exhaust system, for exhausting the exhaust gas flowing through an inner space of the case, to the exhaust pipe, a plurality of partition plates arranged in the case so as to partition the inner space of the case into a plurality of rooms between the gas supply port and the gas exhaust port, a gas distribution port provided in some of the partition plates such that the exhaust gas introduced into the case through the gas supply port, is allowed to flow through the rooms partitioned by the partition plates, in the order, and then exhausted from the gas exhaust port, a trap mechan

Abstract: A new accessory for duct systems for displaying the degree dustiness in a duct network and for trapping heavy and potentially valuable objects as they are cleaned from a duct network. The inventive device includes a housing that has an exterior wall and an open top. The exterior wall has an interior surface that defines an interior of the housing. The open top provides an opening into the interior of the housing. A filter sheet is disposed in the interior of the housing. The filter sheet has a plurality of apertures therethrough. The filter sheet divides the interior of the housing into a first chamber and a second chamber. The exterior wall of the housing has an aperture into the first chamber and an aperture into the second chamber. A cover is dimensioned for coupling with the open top of the housing. The cover closes the opening into the interior of the housing.

Abstract: This invention relates to a filter change indicator that is operable in various orientations of the device incorporating it. For example, the filter change indicator is operable when the device is positioned in either the upright or sideways position. The device incorporating the filter change indicator can be any air moving device which incorporates a cleanable or replaceable filter. The filter change indicator includes a transparent viewing window and a tubulation. The viewing window displays a visible signal when the filter needs changing. The visible signal can be a float retained in the tubulation. The tubulation is a hollow transparent tube which forms an incline plane within the housing. The tubulation includes a first end, a second end and a step. The first end is in fluid communication with an air flow path through the tubulation, and this air flow path is exposed to atmospheric pressure.

Abstract: A filter cell for use as all or as part of a filter panel includes an upper face 1 and a lower face 2. The upper face 1 and lower face 2 includes a set of parallel ribs 3 interconnected across one end by a further rib 4 orthogonal to the ribs 3. A mesh panel 5 is provided between each of the ribs 3 to define a flat surface through which air or gas can flow. The ribs on the upper face 1 cooperate with the ribs on the lower face 2 to define a plurality of open ended compartments spacer frame 6 which increase the size of the compartments by extending the ribbing 3 on the upper 1 and lower 2 faces are provided between upper face 1 and lower face 2. The upper face 1, spacer frames 6 and lower frame 2 are assembled by snap-fit using corresponding male 10 and female 11 lugs. A filter medium is inserted through the open ends into the compartments and a slide plate is used to close the ends.