Abstract: An inertial gas-liquid separator and method is provided, including variable orifice jet nozzle structure having a variable orifice area dependent upon axial movement of a plunger relative to a housing sleeve, and in another embodiment having first and second flow branches, with the first flow branch being continuously open, and the second flow branch having a variable flow controller controlling flow therethrough.

Abstract: A filter for precipitating solid materials from a pressure medium or a gas includes an inlet and an outlet channel implemented in a filter housing. A filter element is disposed in the filter housing. Pressure medium flows through an outer surface of the filter element by means of the inlet channel into an interior area, and from the area to the outlet channel. The outer surface of the filter element, together with an inner surface of the filter housing, delimits an inlet chamber in which the pressure medium encompasses the filter element. The inlet channel and/or the inlet chamber are thereby embodied such that a centrifugal force acting approximately radially to the filter housing acts on the medium flowing into the inlet chamber, whereby the particles can be filtered out of the pressure medium in addition to the filter element.

Abstract: An improved filter assembly (1) is disclosed, particularly for electric cabinets, comprising a filter cloth (5), a conveying sump (7) and a fan (9), equipped with at least one thermal-resistive sensor (11) placed next to at least one hole (13) obtained in the conveying sump (7).

Abstract: An air inerting system for supplying nitrogen-enriched air to a fuel tank on a vehicle includes an air separation module. The air separation module has an inlet for receiving air to separate oxygen, and an outlet for delivering nitrogen-enriched air to a downstream fuel tank on a vehicle. Downstream parallel flow lines of the outlet are each provided with a flow control valve. The downstream parallel flow lines reconnect downstream of the flow control valves to provide a source of nitrogen-enriched air to the fuel tank. An air supply line upstream of the air separation module supplies air to at least a pair of upstream parallel lines. Each of the upstream parallel lines are provided with a shut-off valve. The upstream parallel lines reconnect downstream of the shut-off valves to supply air to a heat exchanger. Air downstream of the heat exchanger passes to the air separation module.

Abstract: An apparatus and method for redirecting fluid flow in a plenum provides flow performance (quality), structural, and economic advantages by using an array of flat blades that is mounted at an angle with respect to the inlet (upstream) fluid flow, such that the blades are tilted with respect to that flow and correspondingly redirect the flow in a desired direction. The apparatus, also referred to as a “GSG” or “graduated straightening grid,” has a range of applications, and offers a number of performance, structural, and economic advantages in large-scale applications. As a particular, but non-limiting example, one or more embodiments of the flow-redirecting apparatus taught herein are configured for use in Selective Catalytic Reduction (SCR) systems where catalytic reactors are used for scrubbing industrial flue gases.

Abstract: An air cleaner device that has a reduced size achieved by curving an air introduction path, that has a cleaner element with extended service life, and in which air flows uniformly in a clean chamber. The air introduction path (21) having an exit (21o) open to a dust chamber (12) of an air cleaner chamber (11) of an air cleaner (10) has a bent path partitioned by a flow regulation plate (22) into an inside branch path (23) inside the curve and an outside branch path (24) outside the curve. Airflows separately flowing into the dust chamber (12) from the exit (21o) after passing through the inside and outside branch paths (23, 24) are deflected upward and directed toward the cleaner element (F) by a first deflection section (33) and a second deflection section (34) arranged in the dust chamber (12). The second deflection section (34) is located at a position closer in the front-rear direction to the exit (21o) than the first deflection section (33).

Abstract: An air cleaner suitable for use with a heavy-duty vehicle includes a cylindrical body that can be mounted to the vehicle so that the body is exposed to an air stream when the vehicle moves in a forward direction. The air cleaner has a boattail, which includes a fin attached to a rear portion of the body. The fin has a vertical orientation and extends in a substantially rearward direction from the body. When the vehicle moves in a forward direction, the boattail reduces the amount of low-pressure air located behind the air cleaner.

Abstract: An air cleaner for a V-type internal combustion engine includes a filter housing with introduction ports formed in both left and right lateral walls communicating with respective air intake ducts and a pair of cleaner elements fixedly disposed in the filter housing to partition the inside thereof into an upper unfiltered air chamber communicating with both the introduction ports and a filtered air chamber disposed below the unfiltered air chamber. The cleaner elements are disposed on both sides of a vertical plane passing through a vehicle body centerline, extend forward and rearward of the air introduction ports, and are inclined to be gradually lowered as they extend away from the vertical plane to face the respective air introduction ports.

Abstract: Air filtration devices and systems are provided to filter conditioned air after air exits an air conditioner module located on a ground support equipment unit but prior to entering a grounded aircraft. Disclosed embodiments include a system with the air filtration unit located along a hose originating from an aircraft ground support unit and a system with the air filtration unit located along a hose originating from an aircraft. Certain embodiments of the air filtration unit include a diffuser, which is configured to couple to a filter and direct air through the filter during operation.

Abstract: A method and apparatus for processing air is described herein. An example apparatus includes a housing, a high-velocity air flow guide, a filter assembly, and a fan. The high-velocity air flow guide includes a first portion and a second portion. The first portion is configured to form a passage within the housing, and the second portion is configured to divert and accelerate air flow of the ambient air from the passage to a chamber of the housing. The filter assembly includes one or more filtering elements configured to receive the ambient air from the chamber. The fan is configured to draw the ambient air from the chamber through the filter assembly and to generate processed air from the ambient air.

Abstract: In at least some embodiments, the present invention relates to an air cleaner having a housing portion, and a low profile rain cover having an opening on an underside of the cover to allow unfiltered air to enter into the air cleaner. Also, in at least some embodiments, the present invention relates to an air cleaner including a housing and an additional component by which the air cleaner is capable of being directly coupled to a carburetor inlet. In some such embodiments, one or more protrusions can be provided within a channel formed by the housing/additional component to influence air flow. Further, in at least some embodiments, the present invention relates to an air cleaner having a shaped wall formed on a housing portion, where the shaped wall includes both an interior surface and an exterior surface by which air flowing within the air cleaner is imparted with helical motion.

Abstract: In one form the present invention provides an apparatus in an airflow path before a particle detector, wherein the apparatus removes a substantially constant proportion of all sizes of airborne particles from the airflow over time. In an example the apparatus includes a flow splitting arrangement configured to divide a fluid flow into a plurality of sub-flows, the splitting arrangement 10 including means for defining a plurality of substantially identically dimensioned flow apertures configured to direct a portion of the fluid into a respective sub-flow.

Abstract: An air drying arrangement for a commercial vehicle is provided having two or more desiccant canisters arranged in parallel on a single air dryer body. The arrangement may include a coupling device that attaches to the body and allows the two or more desiccant containing canisters to mount to the device. The arrangement may be configured to balance the flow of air to each of the desiccant containing canisters when drying air and/or when regenerating the desiccant.

Abstract: A fuel tank inerting system uses two “half systems” for providing inerting gas for the fuel tanks. Each inerting system may be composed of a temperature control and air pressurization unit (TCPU) and an air separation unit (ASU). A cross-ship duct and valve allows using one TCPU (sized for about half capacity or more, but less than full system capacity) connected to two ASUs. The inerting system may provide for redundancy in the TCPU section.

Abstract: An example filter assembly prevents particles from entering a control valve and defines an airflow path between an inlet and outlet. An inlet tube extends from an inlet and defines an inlet passage into a filter housing. Openings within the inlet tube open into an interior space of a filter housing. An outer housing defines a cavity within which the filter housing is secured. The filter housing includes an open top portion that engages a cap that covers and seals the outer housing. The cap holds the filter housing to prevent movement of the filter housing.

Abstract: An air purifier air intake structure is disclosed to have one or a number of air inlets made on the housing of the air purifier adjacent to the air input port thereof for enabling the air purifier to suck in oxygen rich outdoor air during indoor air circulation and purification operation of the air purifier. By means of the one or a number of air inlets in the air purifier adjacent to its air input port to guide in oxygen rich outdoor air for purification by the air purifier, purified air is discharged into the indoor space through the air output port of the air purifier, increasing (supplying) the oxygen content in the indoor air and enhancing the indoor space purification effect of the air purifier.

Abstract: A forced air open-ventilation systems for cooling electrical machines is provided. The forced air open-ventilation system includes an air cleaner having an air chamber with a first end, where air is drawn in from the surroundings, and a second end, opposite the first end, where air is drawn out of the air chamber, via a first outlet. A rotating means is contained within the air chamber and may be driven to rotate about an axis that extends between the first end and the second end of the chamber. The rotating means applies a centrifugal force to any airborne particles entering the air chamber and throws them radially outwards from the central axis. These particles are then drawn out of the air chamber, via at least one second outlet formed adjacent to a radially outer edge of the rotating means, by a high-velocity outlet stream of the open-ventilation system.

Abstract: A filtration system for a particulate-laden stream of gas utilizes a group of fabric bags within the upper chamber of a housing as the means by which particulate matter is filtered out of the gas. The gas inlet into a lower chamber of the housing is provided with an inlet guide that directs the incoming gas against the lower side of a porous diffuser located below the group of bags and spanning at least most of the separation zone defined by the bags. Passages through the diffuser are configured to present an array of nozzles so that the gas is subjected to a pressure drop across the diffuser before flowing to the bags. The nozzle effect causes the particulate-laden gas to spread out evenly on the lower, upstream side of the diffuser and pass through the diffuser at substantially equal velocity at all passages, thereby smoothing the flow and distributing it evenly to all bags.

Abstract: An aspect of embodiments of the invention is to lower fluid resistance applied to gas flow (A, S) flowing within a dust collection system (1) so as to enhance dust collection efficiency of the dust collection system (1) without depending on the number or the two dimensional arrangement of movable elements (40) within the system (1). Embodiments of the dust collection system (1) of the invention includes: a housing (10) defining a cavity (50) therewithin, the housing (10) having a plurality of inlets (53) and at least one outlet (57) for gas; a plurality of movable elements (40) for opening and closing the inlets (53), the movable elements (40) being respectively provided corresponding to each of the inlets (53); a gas flow generating device (20) for generating a gas flow (A, S) from each of the inlets (53) to the outlet (57) during the opening operation of the movable elements (40); and a flow path control device (13) for controlling the flow paths of the gas flow (A, S).

Abstract: A vacuum assembly has a vacuum housing. The vacuum housing has lower and upper ends. The vacuum housing has a cylindrical wall adapted to secure the system onto a work surface. An enclosure assembly has an enclosure housing. The enclosure housing has lower and upper ends. The enclosure housing has a cylindrical wall. The upper end has two semi-circular closure panels. The panels have hinges. The panels are adapted to cover the upper end. The panels having mating semi-circular recesses. In this manner a passageway is formed. A horizontal membrane couples the vacuum and enclosure housings.

Abstract: The present disclosure provides a method, apparatus, and system to mount a filter bag to a wet/dry vacuum cleaner by providing an adapter for mounting the filter bag to a drain opening in the wet/dry vacuum cleaner drum and restricting the typical vacuum port, forcing the vacuum materials to enter through the drain opening and into the bag. The lid of the wet/dry vacuum cleaner can be removed independently of the bag to avoid rupturing the bag. Further, the bag can rest on the bottom of the drum for support.

Abstract: A turbomolecular pump includes: a rotor (30) formed with rotating blades (32) in a plurality of stages, and rotating at high speed; a plurality of fixed blades (33) arranged along axial direction of the pump so as to alternate with respect to the rotating blades (32); a pump housing (34) containing the rotating blades (32) and the fixed blades (33), and formed with an inlet opening (21a); a circular disk (150), provided close to the inlet opening of the rotor (30), and arranged so as to oppose a surface of the rotor (30) radially inward than a root portion of the rotating blades; and a cylindrical mesh structure (153a, 153b), disposed between the inlet opening (21a) and the rotor (30), and made by interlacing fine wires. Particles that strike the rotor and bounce off are captured internally in the mesh structure (153a, 153b).

Abstract: An apparatus and a system is provided that may be utilized to determine oil migration and oil displacement from a pre-oiled air filter. The present invention may also be utilized to determine if oil is displaced from the air filter onto a portion of the apparatus for visualization to a user. The present invention utilizes a demonstration apparatus having a system for forcing air through the oil subjected air filter thereby attempting to force displacement of the oil from the air filter. The apparatus utilizes a blowing means whereby the oil infused air filter is subject to higher than normal air flow and whereby the apparatus has a deflection portion whereby if oil is displaced from the air filter, it is deflected onto the deflection portion where it would be physically viewable to an observer present in the vicinity of the apparatus.

Abstract: An air conditioning apparatus is disposed above an air conditioned space. The air conditioning apparatus includes a case, a bottom surface panel, a filter, and a filter support part. The bottom surface of the case is open. The bottom surface panel covers part of the open portion of the bottom surface of the case. The filter is accommodated within the case. The filter support part detachably supports the filter such that the filter is separated upward from the bottom surface panel by a predetermined gap.

Abstract: The present invention generally relates to a motor vehicle air cleaner assembly that is field or end user convertible to another variety of air cleaner having secondary air induction. The air cleaner is pre-configured to enable a field modification to provide for secondary air induction for admitting heated secondary air to the air cleaner and air filter to aid in melting snow or ice blockage of the air filter and permitting the vehicle to operate in snow and ice air filter blockage conditions.

Abstract: A gas/liquid separator is provided in which separation performance for fluid into gas and liquid is enhanced. A gas/liquid separator includes a body which separates a circulation gas into water and hydrogen gas in a separating space, a supply port from which the circulation gas flows into the inner space, the supply port being provided on the side wall surface forming the separating space, and a discharge port through which the separated hydrogen gas flows out of the separating space, the discharge port being provided on the side wall surface. In this case, the discharge port is provided above the supply port.

Abstract: An apparatus and a system is provided that may be utilized to provide stability to air flow through a hood scoop. The present invention may also be utilized to straighten and smooth out air flow through a hood scoop and accompanying air filter media. The present invention utilizes an air filtration media which may be inserted into at least a portion of a vehicle hood scoop and may filter out particulate and may also slow air flow down temporarily in order to straighten and/or smooth turbulent air flow through the air filtration media. Additionally, the present invention may provide an apparatus that may facilitate more uniform pressure inside the hood scoop of the vehicle.

Abstract: A strainer provided in a refrigerant piping of an air conditioning device through which refrigerant flows includes a cylindrical shell disposed in the refrigerant piping, a cage type filter which includes an opening at one end and a bottom at the other end facing with each other relative to the flowing direction of the refrigerant and a meshed circumferential portion for allowing the refrigerant to pass through, but preventing sludge to pass through an annular passage provided between an outer circumferential portion of the filter and an inner circumferential portion of the cylindrical shell for the refrigerant to flow through and a leading pipe inserted into the refrigerant piping for letting the refrigerant and sludge and having an opening disposed in the cylindrical shell adjacent and opposing to the bottom of the filter and an inner circumferential wall along which sludge flows.

Abstract: A tubular channel is disposed in a path of air that flows from an inlet to a dirty side. The cross sectional area of the tubular channel is smaller than the cross-sectional area of the inlet. A dust outlet is disposed in a wall in a path of the air that flows out of the exit of the tubular channels to the dirty side. The dust outlet extends through the wall of the air cleaner from the inside to the outside. As the air blasts out of the dust outlet, dust in the air cleaner is discharged to the outside.

Abstract: An engine air cleaner includes a cleaner element unit is housed within the upper cover body, and a skirt wall of the upper cover body extends further downward than the suction opening. A seal packing and the cleaner element unit are superimposed and fitted onto an outer periphery of an intake passage within the cleaner cover body. The seal packing is provided with a retaining projection that is tightly engaged with the intake passage. An air cleaner is disposed to be side by side with one side of the engine, a lower part of the cleaner cover body is joined integrally to and supported on the engine together with a carburetor via a pair of connecting bolts, and a reinforcing vertical wall portion of the cleaner cover body facing the engine across a gap is joined integrally to and supported on the engine via another connecting bolt.

Abstract: An inertial gas-liquid separator and method is provided, including variable orifice jet nozzle structure having a variable orifice area dependent upon axial movement of a plunger relative to a housing sleeve, and in another embodiment having first and second flow branches, with the first flow branch being continuously open, and the second flow branch having a variable flow controller controlling flow therethrough.

Abstract: An air filtering unit for a factory includes: an entry duct; a flow expander section fluidly connected with the entry duct, the flow expander section including a flow distribution unit and a flow velocity reduction unit; a filter unit fluidly connected with the flow expander section, the filter unit having a plurality of filter bags, the filter bags being suspended from a tube sheet; and an exit duct fluidly connected with the filter unit. The flow distribution unit includes a series of flow distribution members positioned along a flow path, the flow distribution unit located and configured to substantially equally distribute an airstream along the length of the flow axis into a plurality of divided substreams. The flow velocity reduction unit includes a plurality of flow reduction members, each of the flow reduction members positioned and configured to confront at least one of the divided substreams and reduce the flow velocity thereof.

Abstract: An air cleaner case of an air cleaner used in an engine provides a lower casing holding a cleaner element thereon, and a cover accommodating the cleaner element therein. The lower casing includes a base on which the cleaner element is mounted, an exhaust duct extending downward from the base so that air purified by the cleaner element is conveyed to the intake side of the engine, an inlet duct extending downward from the base along the exhaust duct, and an inlet cylinder extending upward into the accommodating chamber from the base so as to be continuous with the inlet duct.

Abstract: Disclosed herein is a cyclone for separating fine particles from a gas. The cyclone includes a cyclone body having an upper end with an inlet and a lower end with a particulate outlet, gas outlet tube with an upper end that extends upwardly into the lower end of the cyclone body, and a vortex breaker. The upper end of the gas outlet tube is connected to the lower end of the cyclone body by a slip joint. The configuration of the cyclone provides for efficient removal of fine particles as compared to conventional techniques. A vessel containing cyclones, and methods of separation using the cyclones and vessel, also are disclosed.

Abstract: A filtration device that includes a pressure vessel having an inlet and an outlet, the filtration device configured to filter a pressurized fluid stream. In an embodiment, the filtration device has at least one disk-shaped filter element housed within the pressure vessel arranged to filter fluid flowing from the inlet to the outlet, and an inlet flow tube disposed within the pressure vessel proximate the inlet tube, wherein the inlet flow tube is configured to direct the pressurized fluid stream from the inlet tube towards a central portion of the at least one disk-shaped filter element.

Abstract: A particulate filter cartridge has a woven metal fiber filter medium surrounding a perforated support tube. The filter medium is crimped down to the support tube at opposite ends thereof and then welded to the support tube at the crimped regions. A plurality of such cartridges can then be nested within each other and separated by appropriate exhaust gas flow directing baffles to form a particulate filter assembly.

Abstract: An air drying arrangement for a commercial vehicle is provided having two or more desiccant canisters arranged in parallel on a single air dryer body. The arrangement may include an coupling device that attaches to the body and allows the two or more desiccant containing canisters to mount to the device. The arrangement may be configured to balance the flow of air to each of the desiccant containing canisters when drying air and/or when regenerating the desiccant.

Abstract: System for extracting vapor and particulates from a flow of at least an air stream having vapor and particulates, the system having a funnel and a filter unit; an opening of the funnel for receiving the flow of the air stream; an outlet of the funnel connected to an inlet of the filter unit, the inlet receiving the air stream. The filter unit includes a housing, a first and a second filter, a ventilation unit and a filter unit outlet; the housing having a first, second and third chamber; the first and second chambers being separated by the first filter, the second and third chambers being separated by the second filter; the inlet being located in the first chamber; the ventilation unit being located between the third chamber and the outlet and in use for creating an underpressure in the first, second and third chambers.

Abstract: An inertial gas-liquid separator removes liquid particles from a gas-liquid stream and has a variable orifice area variable along an axial direction and dependent upon axial movement of a plunger relative to a housing sleeve.

Abstract: A smoke evacuating system for use during surgical procedures, particularly minimally invasive procedures involving the use of a laser or cautery at a surgical site having an associated higher than ambient pressure, wherein the system includes a filter with a site side and an outlet side and a fluid conduit extending between the surgical site and the filter. The filter includes a filter media and a housing substantially surrounding the filter media with a space between the filter media and the housing to collect condensed vapor. The filter exhibits low resistance or a low pressure drop and resists fluid flow, whereby the higher than ambient pressure is not substantially diminished and generates a fluid flow in the fluid flow path tending to carry smoke to and through the filter.

Abstract: The present invention relates to an extractor hood that comprises an extraction conduit and a delivery conduit, the first one housing an air treatment unit that extracts air through the lower mouth of the same conduit, and the second one housing an air treatment unit that produces a forced air flow with inside-outside direction, which is suitably conveyed by a deflector with downward inclination to generate a pneumatic screen above the cook top that conveys fumes rising from the cook top towards the lower mouth of the extraction conduit.

Abstract: Separation systems can utilize a combination of forces to separate constituent components of a working fluid from each other. Some separation systems utilize one or more of centrifugal and gravitational forces in the purification of hydrogen gas. Some separation systems can utilize one or more of electromotive and magnetic forces in the purification of hydrogen gas.

Abstract: A structure of an impurities collecting bucket for an air separator and purifier, primarily structured from a bucket and an air guide cover, wherein the air guide cover covers an opening at an upper end of the bucket, and is provided with an air inlet and an air suction port. A guide pipe extends from the air inlet and connects to a work place, and another guide pipe connects the air suction port to an air inlet of an air separator and purifier for series operation.

Abstract: A dust collector includes a shell, an exit tube, an inner tube, a suction device, a first dust container, a bypass tube and a first dust bag. The shell defines a first receiving room therein. The exit tube defines an exit passage therein. The inner tube defines a connection passage which has a first opening and a second opening. The first opening communicates the first receiving room, and the second opening communicates the exit passage. The suction device provides the exit passage with a negative pressure. The first dust container defines a second receiving room therein. A mesh is disposed on a bottom surface of the first dust container to divide the second receiving room into a first chamber and a second chamber. The bypass tube defines a bypass passage therein, and it communicates the connection passage with the second chamber. The first dust bag is disposed in the first chamber.

Abstract: An ecologically clean water condensation engine exposed to a humid wind, said water condensation engine includes a cascade of sequential profiled horn-tubes and a set of wing-like profiled details. The cascade of sequential profiled horn-tubes forms a fast and cooled out-flowing air flux, which reaches the set of wing-like profiled details. The set of wing-like profiled details acts on the fast and cooled out-flow air flux, which in turn provide acceleration of air portions and eddying and vortices with in the air portions. The air portions inherently undergo a decrease in inner pressure accompanied by a further temperature decrease, thereby, triggering condensation of water-vapor into water-aerosols and the water-aerosols collect into drops of dew upon surfaces of the wing-like profiled details.

Abstract: The invention relates to a droplet separating system for gas washers and similar, comprising at least one droplet separating layer and a rectifier layer which is arranged upstream in the direction of the flow of gas. The rectifier elements of the rectifier layer are arranged in the form of a V or an upturned V having opposite inclinations to the droplet separating profiles of the droplet separating layer. As a result, the rectifier layer is contaminated in a slow manner due to the increased performance of the droplet separating system.

Abstract: Methods, techniques, and constructions are provided for use to apply an evacuation valve arrangement on an air cleaner assembly that is configured for pulse jet operation. An example evacuation valve arrangement is provided which comprises a valve member in the form of a sleeve that extends completely around a sidewall portion of an air cleaner housing of a pulse jet air cleaner. Examples are depicted in which the sidewall portion can comprise: a portion of a housing sidewall section that surrounds an installed filter cartridge, in use; a portion of an access cover; or, a drop tube secured to a portion of the housing, for example either on an access cover or on another portion of a housing. Specific features and alternatives are described. Also, methods of assembly and operation are described.

Abstract: An air cleaner element includes an element body, which filters an air flow, and a guard member secured to the element body. The air flow is introduced into the element body through a first end surface of the element body. The air flow is then filtered and sent out from a second end surface. The guard member has a leg portion, which is secured to an outer circumferential portion of the first end surface of the element body. The guard member projects toward the upstream side of the air flow and includes guard portions which are connected together at the distal ends of the guard portions. The guard portions function as a handle when the element body is removed or installed and as a blockage portion that prevents large-sized foreign matter from entering the element body.

Abstract: An air filtering device and an air cleaning system of a semiconductor manufacturing apparatus to reduce cost and increase manufacturing productivity. The air filtering device may include a frame having an open aperture coupled to an air supply line. A buffer frame configured to be inserted into the frame may include a plurality of slot parts, each slot part having a plurality of air in/out apertures through which air may flow in or out from the buffer frame. A plurality of filters may be releasably fastened to the plurality of slot parts to filter pollution material contained in air flowing through the air in/out apertures. An air interrupter for interrupting air flowing through the air in/out apertures may be used when replacing the plurality of filters, thereby providing purified air to the semiconductor manufacturing apparatus during the replacement.

Abstract: Behind a front panel of an air purifier are formed guide paths on the right and left sides thereof. A space between the front panel and a filter unit is partitioned by a partition plate into a front panel rear space and a filter unit front space. Part of an airflow that has entered the guide path through an air intake enters the filter unit front space, and the other part thereof enters the front panel rear space. When entering the front panel rear space, the airflow takes a sharp turn at a sharp turn corner. As a result, coarse dust is separated from the airflow, and the separated coarse dust falls into a dust box.