Abstract: A portable hood may include a base, a head, a column, and a fan. The head may introduce air thereinto and discharge the introduced air to the outside. The column may be coupled eccentrically to a side of the head in a horizontal direction. Further, the fan may be located inside of the head such that the fan is eccentric to the head toward the column.

Abstract: A smoke and dust treatment apparatus for welding, said apparatus comprising a polishing and dust extraction module and a smoke and dust purification module. The polishing and dust extraction module comprises a double-layer dust extraction cover (3), a protective cover (2), an industrial brush (4), a first air guide portion, a second air guide portion (24) and a drive motor (22), the drive motor (22) driving the industrial brush (4) to rotate at high speed to perform polishing. During welding and polishing, a mechanical arm (6) drives the double-layer dust extraction cover (3), and a suction hole (20) of the double-layer dust extraction cover (3) and a suction guide hole (19) on the industrial brush (4) simultaneously take in toxic gas and debris such as iron filings.

Abstract: A system for capturing airborne particles from a mixing apparatus for mixing mineral based building materials, particularly such materials containing a silica based material, wherein there is a hood assembly attachable to a mixing apparatus and positionable such that airborne particles generated in loading the mixing apparatus are drawn into the hood, the hood being operatively connectable to a vacuum/filtration apparatus.

Abstract: A method of regulating a setting time of a bone filler material, the method comprising: (a) combining at least two filler material components to form a biocompatible mixture; (b) choosing a setting time for the mixture; and (c) regulating a temperature of the mixture to influence reaction kinetics so that the mixture does not set before the chosen setting time.

Abstract: A fume evacuation system is designed to remove smoke, fumes, and particulate from a metal-working or other application. The system may include a cart-type base unit or may be incorporated into a fixed or semi-fixed installation that uses suction to draw air (e.g., containing smoke, fumes, and particulate) away from the metal-working application. The fume evacuation system includes a hood that creates an arduous flow path and varying velocity profile, which cools and separates any particulate matter in the suctioned air. The arduous flow path may include multiple sharp turns created by an inner deflector component and an inlet tube. The inlet tube may further contain baffles to cool particulates from the suctioned air.

Abstract: A range extractor hood includes a screen, at least one filter element and at least one pivot bearing which swingably supports the at least one filter element on the screen. At least one locking member retains the at least one filter element to the screen. Located on the screen is a releasing device for, at least partially, releasing the locking member and retention of the filter element.

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 fume evacuation system is designed to remove smoke, fumes, and particulate from a metal-working or other application. The system may include a cart-type base unit or may be incorporated into a fixed or semi-fixed installation that uses suction to draw air (e.g., containing smoke, fumes, and particulate) away from the metal-working application. The fume evacuation system includes a hood that creates an arduous flow path and varying velocity profile, which cools and separates any particulate matter in the suctioned air. The arduous flow path may include multiple sharp turns created by an inner deflector component and an inlet tube. The inlet tube may further contain baffles to cool particulates from the suctioned air.

Abstract: A saw enclosure having a waterproof metal base pan, with integral receiver brackets for supporting enclosure frame work, and a built in shop-vac attachment port for using a vacuum to produce negative air pressure within enclosure; removing dust, moisture and particulate laden air. The saw enclosure framework assembly includes an electric control panel comprising of a switch controlled, duplex, GFCI outlet, for simultaneously energizing the saw and vacuum, and a continuously powered duplex outlet for powering a jig saw, grinder, drill, light, or any other electrical item. The enclosure, a seamed and fitted cover of flexible fabric or plastic, includes weights or magnets to ensure a tight fit at the base pan. All components disassemble quickly, and fit within base pan, which has a detachable cover for ease of transport.

Abstract: A reverse oblique air curtain exhaust cabinet comprises a cabinet that has a bottom plate and an elongate air blow slot is provided in front of the bottom plate. Through the elongate air blow slot, air is blown upward at an oblique angle toward the rear plate of the cabinet. An air-extraction hood is provided in a space defined above the bottom plate in a way of being vertically movable relative to the cabinet. The air-extraction hood has an elongate air-extraction part that is parallel to the elongate air blow slot in a way that the elongate air-extraction part is above and spaced from the elongate air blow slot toward the rear plate of the cabinet. Thereby, an oblique air curtain that flows upward is formed to remove the pollutants between the oblique air curtain and rear plate and left and right lateral plates in a more energy-saving way.

Abstract: An apparatus for the extraction of gases has a flexible duct with an interior therein, a polymeric support extending in the interior of the flexible duct, a first anchor that secures an end of the polymeric support, a second anchor that secures an end of the flexible duct, and a duct connector. The first anchor secures the end of the polymeric support to the duct connector. The second anchor secures the end of the flexible duct to the duct connector. The polymeric support is elongated. The polymeric support has a taper and a thickness suitable for holding the flexible duct in a fixed position. The polymeric support is formed of a polycarbonate material.

Abstract: The torque, due to the weight of the arm, is balanced according to the angular position of the arm by a contrast spring acting perpendicular to the axis of rotation of the arm. The spring is controlled by a cam integral with the arm, is housed in a container closed by a wall acted on by the profile of the cam, and rests on a guide disk whose position relative to the container is adjusted by means of an adjusting screw to calibrate the precompression of the spring according to the minimum torque due to the weight of the arm. In another embodiment, at least one contrast spring acts parallel to the axis of rotation of the arm, and is controlled by a cam edge of a cylinder for axially moving a corresponding sleeve housing the spring.

Abstract: A reverse oblique air curtain exhaust cabinet comprises a cabinet that has a bottom plate and an elongate air blow slot is provided in front of the bottom plate. Through the elongate air blow slot, air is blown upward at an oblique angle toward the rear plate of the cabinet. An air-extraction hood is provided in a space defined above the bottom plate in a way of being vertically movable relative to the cabinet. The air-extraction hood has an elongate air-extraction part that is parallel to the elongate air blow slot in a way that the elongate air-extraction part is above and spaced from the elongate air blow slot toward the rear plate of the cabinet. Thereby, an oblique air curtain that flows upward is formed to remove the pollutants between the oblique air curtain and rear plate and left and right lateral plates in a more energy-saving way.

Abstract: A method and apparatus for applying an atomized liquid solution upon a person, comprising a spray enclosure booth; an exhaust vent located below an anticipated user's facial area zone, the exhaust vent disposed within the bottom tray or a lower area of at least one wall or a lower area of a door and configured for exhausting ambient atomized liquid solution from the spray enclosure booth; a rigid conduit support defining a central air flow conduit connected to a bottom tray and pneumatically connected to an exhaust vent and providing structural integrity to the enclosure booth; an atomizing spray head assembly movably connected to the rigid conduit support and physically supported by the rigid conduit support; and an exhaust system configured to exhaust ambient atomized liquid solution from the spray enclosure booth by drawing atomized solution into the exhaust vent then through and out of the rigid conduit.

Abstract: An air filter for electric welding includes a box having an opening for connecting with a sucking tube, an dividing plate dividing the box into an upper chamber communicating with the opening and a lower chamber, a spark blocker inside the upper chamber, a movable filter device set under the spark blocker inside the upper chamber and provided with a cloth filter, a blower inside the lower chamber, and an extractable screening device installed outside it and communicating with the lower chamber. In using, when the blower is switched on, the air is sucked in from the sucking tube to the spark blocker, the movable filter device, the blower and the extractable screening device orderly, blocking sparks completely and achieving an effective filtration.

Abstract: Exhaust capture and containment are enhanced by means of automatic or manual side skirts, a sensitive breach detector based on interference effects, a combination of vertical and horizontal edge jets, and/or corner jets that are directed to the center diagonally from corners. Associated control functions are described.

Abstract: The present invention provides a preventive maintenance hood suitable for a reaction chamber of a semiconductor machine and connected to an exhaust pipe. The preventive maintenance hood includes a hood body, an air curtain forming apparatus, and an exhaust pipe connector. The hood body includes a first opening and a second opening. The first opening is located at a bottom of the hood body and adapted to cover an exit of the reaction chamber, while the second opening is located on a sidewall of the hood body. The air curtain forming apparatus is disposed on the hood body and located at an edge of the second opening. The exhaust pipe connector is mounted on the hood body and connected to the exhaust pipe.

Abstract: A filter housing, a duct arm and a hood which is positioned near the fume source as the duct arm extends between the hood and the filter housing for conveying the fumes from the hood to the filter housing. The filter housing includes a motor for generating suction at the hood inlet and for propelling the fumes out of the filter housing through a housing outlet. The motor has a power ranging from 7.5 to 10.0 horsepower for moving air through the assembly at speeds exceeding 6000 feet per minute (fpm) and at flow rates exceeding 2100 cubic feet per minute (cfm). The hood has a depth of 12 inches and the hood inlet has a width of 36.44 inches and a height of 12.51 inches.

Abstract: The invention relates to an air holding device comprising a channel system raised from a suction opening disposed at a height of a workstation generating dirty air or vapours and leading to at least one outlet opening. An exhausting fan is placed between a prefilter and at least one odour filter. The channel system is embodied in the form of an exhaust air box disposed downstream of the exhaust fan. The lateral surface of the exhaust air box comprises an air inlet which is connected to the downstream side of the exhausting fan. The other lateral surfaces are selectively provided with air outlet openings covered respectively with an odour filter having an adjustable air resistance. Said odour filter preferably consists of a foam material coated with active carbon and the air resistance thereof is selectable according the thickness and/or porosity of the foam material.

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 portable smoking room having a flexible enclosure defining a room detachably mounted on a frame is provided. A duct is detachably mounted to the frame for transporting smoke laden air within the flexible enclosure outside of the flexible enclosure. A fan detachably mounted to the duct creates negative pressure within the flexible enclosure such that smoke laden air within said flexible enclosure may be drawn out though the duct and ambient air from outside may be drawn in through a plurality of air intake apertures in the flexible enclosure. The frame of the portable smoking room may be disassembled when the enclosure and the duct are detached from the frame such that the flexible enclosure, the frame, the fan, and the duct may be transported and reassembled at another location.

Abstract: A multiposition exhaust recovery system for removing vehicle exhaust gases from a plurality of positions in a work area includes a vertical support column, a pair of pivotally attached tubular arms rotatable by separate power means for each arm, a flexible tube connecting the two arms, an exhaust collecting hood connected to one end of the tubular arms and a suction source connected to the other end of the tubular arms. A portable controller controls operation of the system.

Abstract: A portable ventilator for removing deleterious gasses from a welding site provides a funnel-like collection head structurally carried by an electrically non-conductive rigid dispersement tube carrying a powering structure. The powering structure provides pressurized gas from an external source through an adjustment valve to an input nozzle carried in axial alignment in the channel defined by the dispersement tube spacedly adjacent the joinder of the collection head with the dispersement tube to output pressurized gas toward the distal output end of the dispersement tube.

Abstract: An pressure differential distribution system which offers an pressure differential reaction element (1) made of a comfortable, flexible pressure differential interface (2) that is attached to a support element (3), which in conjunction with a difference in pressure between the interior volume of the differential reaction element (1) can conform to various extended or reduced conformers. The flexible pressure differential interface (2) may retract within an enclosure(4). An emission removal adaptor (12) or terminal interface (23) may be coupled to a substance source (10) to capture or move substances on a pressure differential from a first zone to a second zone.

Abstract: A fume hood is pivotally mounted on a vertically extending axle fixed to a chemical tank and extending through a sleeve in the hood allowing the fume hood, with a flexible coupling to an exhaust blower, to pivot from a use position adjacent the tank to a position pivoted away from the tank to allow an operator to gain access to the tank. In one embodiment, the hood includes a support leg for supporting the end of the hood remote from the pivot connection to the tank.

Abstract: A telescopic extraction arm (1), having an outer tube (4) and an inner tube (6) displaceably and rotatably fitted therein. Via balancing rings (14, 16) fixed on each tube respectively, which are kept a pre-determinable distance apart by a stop member (18) arranged in the outer tube (4), the tubes can be easily displaced and locked in relation to one another with a negligible degree of the “drawer effect” occurring in conventional telescopic arrangements.

Abstract: A vacuum conduit system for removal of fumes and air borne particulate matter includes a primary duct and a plurality of flexible secondary ducts mounted in fluid cooperation to the primary duct. The primary duct includes hollow rigid conduit sections interspersed between, and in fluid communication with, hollow flexible conduit sections. An upstream end of the primary duct is sealed substantially air-tight. An opposite downstream end of the primary duct cooperates with an air extraction means for extracting air from the primary duct. Secondary ducts may be mounted at their downstream ends to the rigid conduit sections and inclined at a first angle relative to the rigid conduit sections so that secondary airflows leaving the downstream ends of the secondary ducts are inclined into an airflow stream in the primary duct so as to be directed in a downstream direction of the airflow stream in the primary duct to generally equalize vacuum levels at the downstream ends of the secondary ducts.

Abstract: An adjustable duct assembly for the collection of fumes, dust and the like comprises two duct sections pivotally connected end to end and to a base by an external duct support system. The duct sections are retained in a selected position without the need for any friction fittings by a combination of a counterbalance arm extending from the duct support of a lower or outer duct section beyond the pivot point of the elongate arms, to counterbalance the lower or outer arms, and a retraction or tension-applying arm which holds the inner duct section in position.

Abstract: The conduit (5) includes a rotary fitting (11), and two segments (18, 19) elbow-connected to each other and each having an articulated mechanism (23, 24) including a par of U-section bars (26, 27) connected to each other in the form of an articulated parallelogram by means of two articulated elements (37, 44; 44, 51). A spiral compression spring (35, 36) is housed between each pair of bars (26, 27), and is compressed between a disk (55), integral with one of the bars (26, 27), and a flange (64) is sliding along a threaded rod (62). The flange (64) is locked on the rod (62) by means of a nut (67), and the rod (62) is connected to a lever member (69) pivoting on one of the articulated elements (37, 44) so as to adjust the action of the spring (35, 36) as a function of the angular position of the relative segment (18, 19) with respect to the articulated element (37, 44).

Abstract: The conduit (5) includes a rotary fitting (11), and two segments (18, 19) elbow-connected to each other and each having an articulated mechanism (23, 24) including a pair of U-section bars (26, 27) connected to each other in the form of an articulated parallelogram by means of two articulated elements (37, 44; 44, 51). A spiral compression spring (35, 36) is housed between each pair of bars (26, 27), and is compressed between a disk (55), integral with one of the bars (26, 27), and a flange (64) sliding along a threaded rod (62). The flange (64) is locked on the rod (62) by means of a nut (67), and the rod (62) is connected to a lever member (69) pivoting on one of the articulated elements (37, 44) so as to adjust the action of the spring (35, 36) as a function of the angular position of the relative segment (18, 19) with respect to the articulated element (37, 44).

Abstract: The invention relates to a medical-technical or dental-technical work table (1) which in its forward region of its table surface (2a) has a protection arrangement (11) having a protection plate (11c) in upwardly extending arrangement, which protection plate is held on the work table by means of a holder (12), whereby there is provided a rearward rear-wall-like protection arrangement part (11b) having a rear wall (11d; 52) behind the protection plate (11c) which part is positionable in a disposition on the work table (1) and/or on a carrier arm (14) in which the rearward protection arrangement part (11b) forms with the protection plate (11c) a hood-shaped protection arrangement (11).

Abstract: A system which reduces the transmission of noxious fumes into the surrounding air during the application of a heated liquid roofing product on a roof. A mobile tanker or kettle contains a supply of the heated liquid. The air space within the tanker or vessel above the liquid product communicates with a mobile filtration unit by a first duct. A rooftop carrier for the liquid product has a fume collection hood which communicates with the filtration unit by a second duct. A blower in the filtration unit creates negative pressure which draws the noxious fumes from the tanker or vessel and carrier through the ducts and into and through the filtration unit. The filtration unit has a series of airtight chambers mounted on a mobile truck bed, each containing a different type of filtering medium to remove various components of the noxious fumes as the fumes move through the filtration unit.

Abstract: A movable overhead ventilation assembly is provided for use in a work facility to be positioned in close proximity to a source of airborne environmental material. The ventilation assembly includes a supporting frame located within the work facility. The frame includes a longitudinally-disposed overhead track. A movable chassis is carried by the track. A ventilation housing is carried by the chassis for overhead translational movement of the ventilation housing within the work facility. The ventilation housing includes a plurality of walls, and has at least two openings therein defining respective inlet and outlet zones thereof. An exhaust fan is located within the ventilation housing between the inlet zone and the outlet zone for creating an upwardly moving air stream in the area surrounding the source of airborne environmental material.

Abstract: A system which reduces the transmission of noxious fumes into the surrounding air during the application of a heated liquid roofing product on a roof. A mobile tanker or kettle contains a supply of the heated liquid. The air space within the tanker or vessel above the liquid product communicates with a mobile filtration unit by a first duct. A rooftop carrier for the liquid product has a fume collection hood which communicates with the filtration unit by a second duct. A blower in the filtration unit creates negative pressure which draws the noxious fumes from the tanker or vessel and carrier through the ducts and into and through the filtration unit. The filtration unit has a series of airtight chambers mounted on a mobile truck bed, each containing a different type of filtering medium to remove various components of the noxious fumes as the fumes move through the filtration unit.

Abstract: A fume and/or dust collection apparatus adapted for concentrated sources of fumes and particulate matter includes an elongated duct connected at one end to a vacuum source and adapted to be supported by a wall bracket or a portable console and a fume collection hood at the opposite end of the duct. One or more flexible joints are interposed in the duct between the support bracket and the hood. Joint support mechanism for each flexible joint includes opposed pairs of pivotally connected arms which interconnect rigid sections of duct on each side of the flexible joint. The connections between the arms of each set include a friction clutch and ratchet and pawl mechanism which permits free movement of the flexible joints in a direction which is opposite that which the hood would move under its own weight while providing for counterbalancing the weight of the apparatus distal of the support bracket and a positive force required to position the hood precisely in the other direction.

Abstract: An adjustable device for exhaustion and/or supply of gases and gas supported particles, the device comprising at least one exhaustion and/or supply conduit which is pivotable in at least a vertical direction, whereby at least one force-producing balancing device is provided for balancing the exhaustion and/or supply conduit. In order to provide at such an adjustable device that the balancing device generates balancing forces which correspond with the correct balancing requirement, the force-producing balancing device cooperates with a compensating device which compensates for the differences between the balancing force that the force-producing balancing device exerts on the exhaustion and/or supply conduit and the force required for balancing the exhaustion and/or supply conduit in substantially all its positions.

Abstract: A hood and duct system that is lightweight, easy to install, and has at least four different adjusting points which allow exact placement for optimum operational results. The hoods are made from lightweight, clear polycarbonate so that the operator can view the equipment associated with the hood. The ducts are also made of lightweight material such as polypropylene. Also the hoods have an outwardly extending, bubble-like feature on one side so that the associated equipment can be operated without moving or removing the hood.

Abstract: An exhaust ventilation apparatus to be temporarily mounted in a continuous pulp digester or similar elongated vessel to provide local air ventilation from one or more selected worksites in the vessel. An exhaust duct extending upwardly to an outlet opening has numerous inlet ports spaced along it. Venturi type air movers each having an air collection conduit attached to it are connected to several of the inlet ports of the exhaust duct. Each air collection conduit is mounted with an inlet located near one of the selected worksites to draw polluted air out of the vessel through the exhaust duct. The air movers and/or the air collection conduits are easily movable as work progresses.

Abstract: An air filtration apparatus includes a lower intake duct and an upper exhaust duct interconnected by a telescoping vertical pipe section permitting vertical length adjustability of the exhaust duct relative to the intake duct. A blower is mounted in the vertical pipe section to draw air through an intake opening in the forward end of the intake duct, through the vertical pipe section and outwardly through an exhaust opening in the bottom surface of a forward end of the exhaust duct. Particulate filters are mounted in the intake and exhaust openings. A length adjustable upright extending between the intake duct and exhaust duct permits selective adjustment of the height of the exhaust duct over the intake duct. A filter rack on the forward end of the intake duct includes a clamping apparatus which permits various sizes of filters to be inserted in the filter rack.

Abstract: An arrangement for the extraction of harmful gases from workplaces, the arrangement (1) exhibiting a carrier arm system (9) having at least two arms (19, 20, 21) connected telescopically with each other so that the carrier arm system (9) can be given different lengths, whereby the carrier arm system (9) is swivelable around a horizontal spindle (17) so that it can be swivelled in a vertical direction and placed in different positions between a downward-directed, preferably substantially vertical end position and an outward-directed preferably substantially horizontal end position.

Abstract: An exhaust gas system for receiving and treating exhaust gases from different processing tanks including a hood supported by a moveable crane to direct exhaust gases from a selected tank to a selected exhaust duct. Exhaust gas then flows to a treatment site. A connector system is provided to connect the duct to the hood/crane combination. A flow rate sensor and air admission damper system is provided in association with the duct to sense the flow rate in the duct, to permit the addition of ambient air to the duct, by opening the damper, and thus assure a substantially constant flow rate to the treatment site.

Abstract: An exhaust hood system comprising an exhaust fan fastened to a window frame of a room and covered with a hood having an intake port coupled with a guide tube being fastened to the wall of the room by a holder, a series of universal connecting tubes linked together and connected to the guide tube by swivel connectors, and an exhaust connected to the series of universal connecting tubes for carrying smoke outside the room through the series of universal connecting tube upon operation of the exhaust fan, the series of universal connecting tubes being turnable and bendable for permitting the exhaust hood to be moved to the desired position and direction to suck in smoke.

Abstract: Adjustable local extraction device comprising a suction tunnel, an exhaustion device connected to one end of the suction tunnel, and a nozzle connected to a second end of the suction tunnel. A filter is provided within the suction tunnel.

Abstract: A hood is assembled of modules including a central make-up air plenum module directly over the heating stations of a conveyorized double-deck oven, an exhaust plenum module atop the makeup air plenum and downwardly-opening end modules overhang the conveyor end portions extending outside the sides of the oven heating chambers. The end modules have make-up air directors aiming make-up air upward along the undersides of removable panels having slots therein to accelerate exhaust flow into a chamber below filters to effectively remove fumes from the areas above the conveyor ends. The overhanging end modules also have partitions therein cooperating with the walls of the overhang portions to provide ducts at the front of the overhang portions to capture fumes from the area above the front of the conveyor ends. Air flow guides around the extending portions of the conveyors assist.

Abstract: An exhauster arm assembly for capturing gaseous fumes which comprises a base member connected to a support structure, a hood member, a plurality of rigid tubular sections disposed between the base member and the hood member, and a plurality of flexible tubular sections interconnecting the base member, the rigid tubular sections and the hood member such that fluid communication is provided between the base members and the hood member. A plurality of joint assemblies pivotally support the hood member and the rigid tubular sections. An actuator, controlled from a switch assembly located on the hood member, is mounted on the base member and the adjacent rigid tubular section to precisely position the hood member.

Abstract: A room comprise of localized region (10) for air conditioning wherein conditioned air or totally fresh air can be directed to certain region of the room. A path of air flow may comprised of a ceiling air collector/distributor (80) joining with a floor air collector/distributor (41) by a duct (18) having the localized air conditioning region (10) link the floor air collector/distributor to the ceiling air collector/distributor to complete the circuit while maintaining the characteristic of air conditioning specific portion of the room only but not the whole room.

Abstract: An environmental chamber comprising a transparent dome shaped housing having an annular conduit, including an exhaust port, affixed to the base of the housing. The housing securely fits over an end of a chemical container, to create a controlled environment within the encapsulated space between the housing and the container. Two cylindrical openings at the top of the housing allow chemical transfer hoses to be connected to the chemical container openings. A pair of gloved access ports allow an operator to access the encapsulated space to manipulate connections between the transfer hoses and the chemical container openings. The top of the housing also includes an intake port for delivering clean purging material into the encapsulated space in order to purge the encapsulated environment of any chemical that escaped from the chemical openings during hook up of the transfer tubing.

Abstract: A focussed ventilation method and apparatus for a work spot wherein at least a first focussed suction (11) and at least one additional focussed suction (13) are arranged to draw the air and/or gas and/or excess heat of the work spot, and arranged to interact so that the first focussed suction (11) draws the more detrimental air in quality than that drawn by the additional focussed suction (13).

Abstract: A said suction hood (1) being connected to a gas extraction system (7) and preferably suspended on a movable arm system (4) permitting the suction hood (1) to be set in various positions relative to an area (2) from which the injurious gases (G) are extracted. For substantially increasing the depth of the suction hood when required, the suction hood (1) includes at least one and preferably three movably mounted wall elements (15, 16, 17) which is or are settable in a folded position or folded positions and which is or are unfoldable into a position or positions wherein it or they gives or give the suction hood (1) a fume cupboard like shape and function.

Abstract: An apparatus for filtering contaminated gases. An extraction device provides a slow passage for the gases. The extracton device is in fluid communication with an intake port of a fan aggregation. The fan aggregation provides a vacuum for drawing the gases through the extraction device. The fan aggregation is rigidly supported on top of a filtration container. The gases are expelled by the fan aggregate through an exhaust port and into an interior chamber of the filtration container. A filter blocks the passage of contaminant components of the gases and permits the passage of noncontaminant of the gases from the interior chamber to the atmosphere. A gas-permeable housing surrounds the filter to retain the filter and support the weight of the aggregate.