Abstract: A pneumatic device (1) has at least one venting path (10) for venting the pneumatic device (1) in an outflow direction (R1). The venting path (10) includes a first volume (12), through which a flow can pass, a first compressed-air passage (14), and a sealing mechanism (18). The first compressed-air passage (14) pneumatically connects the first volume (12) to a pressurized part (16) of the pneumatic device (1). The sealing mechanism (18) changes between a normal state (Z1) and a sealing state (Z2). In the normal state (Z1) a flow can pass through the first compressed-air passage (14) both in the outflow direction (R1) and in an oppositely directed inflow direction (R2). In the sealing state (Z2) a flow can pass through the first compressed-air passage (14) only in the outflow direction (R1).

Abstract: A filter assembly for an engine, has: a housing having a longitudinal axis and defining an internal volume, the housing having an open end and defining an oil inlet and an oil outlet, the internal volume having a first zone and a second zone, the first zone in fluid communication with the oil inlet, the second zone in fluid communication with the oil outlet; a cartridge assembly having a filter cartridge, and a cover sealingly engageable to the housing to close the open end of the housing, the filter cartridge axially locked in the housing by the cover, the cover removably securable to the housing; and a sealing member between the housing and the cartridge assembly, the sealing member separating the first zone from the second zone such that the first zone communicates with the second zone through the filter cartridge.

Abstract: An ostomy appliance having an appliance wall of flexible sheet material forming a cavity for containing a stomal output. The wall has a stomal inlet for receiving the stomal output and a gas vent for allowing the stomal gas to migrate out of the cavity. A filter arrangement is mounted to the appliance wall and has a filter channel extending from a filter channel inlet to a filter channel outlet. The filter channel inlet is located in the cavity for receiving the stomal output from the cavity and the filter channel outlet is mounted in communication with the gas vent for allowing stomal gas to migrate out of the filter channel to the gas vent. A separation element extends along the filter channel for maintaining the filter channel in an open configuration along part of the filter channel for allowing stomal gas to pass therethough.

Abstract: A gas and liquid separation system could be said to have a passage with an inlet connected to receive a mixed gas and liquid flow. An air separation tube extends into the passage at a location downstream of where the inlet is connected with an upstream tube end upstream in the passage relative to a downstream tube end. The upstream tube end provides an obstruction to the mixed gas and liquid flow, to cause separation of the gas from the mixed gas and liquid flow. A liquid tube is connected to the passage at a location downstream of the air separation tube.

Abstract: A vent/drain cover for an electronics enclosure includes a cover body defining an axis and a surface with a first wall protruding from the surface in a direction and a second wall protruding from the surface in the same direction but displaced radially from the first wall. The first wall has a first channel formed therein that is defined by a portion of the first wall that does not extend as far from the surface as the balance of the first wall. The second wall has a second channel defined by a portion of the second wall that does not extend as far from the surface as the balance of the second wall, the first channel being circumferentially offset from the second channel. Electronics enclosures and methods of venting electronics assemblies are also described.

Abstract: A system for hydrocarbon production comprising a host for receiving produced hydrocarbon; an offshore hydrocarbon production facility comprising: a production wellhead for connection to a subsea hydrocarbon reservoir; a production platform configured to receive produced fluid from the wellhead and being in fluid communication with the host via a long distance pipeline wherein the wellhead is local to the production platform, and the production platform is configured to process the produced fluid to provide a semi-stable oil product suitable for exporting along the long distance pipeline to the host; wherein the host is configured to store the semi-stable oil product.

Abstract: A base plate of an ostomy appliance includes a first adhesive layer and a masking element. The first adhesive layer includes a stomal opening with a center point and a proximal surface configured to be attached to a skin surface of a user. The masking element is arranged on a distal surface of the first adhesive layer and is more insulative than the first adhesive layer. A plurality of electrodes is arranged on the distal surface of the first adhesive layer, where each electrode includes a sensing part and a conductor part. The masking element is arranged between the conductor part of each electrode and the first adhesive layer. The electrodes are formed on a proximal surface of a support layer.

Abstract: An air permeable cap for a vehicle may include: a cover part formed in a cylindrical shape with a closed end part, and having a plurality of guide ribs radially formed on an inner circumferential surface thereof; a foam part inserted and installed in the cover part so as to be contacted with the guide ribs, and having a ventilation hole formed on one side thereof; a membrane part installed between the foam part and the cover part, and configured to block a flow of water through the ventilation hole and allow a flow of air through the ventilation hole; and an adhesion retention part coupled in a concave-convex shape to retain an adhesion force between the foam part and the cover part.

Abstract: A vent/drain cover for an electronics enclosure includes a cover body defining an axis and a surface with a first wall protruding from the surface in a direction and a second wall protruding from the surface in the same direction but displaced radially from the first wall. The first wall has a first channel formed therein that is defined by a portion of the first wall that does not extend as far from the surface as the balance of the first wall. The second wall has a second channel defined by a portion of the second wall that does not extend as far from the surface as the balance of the second wall, the first channel being circumferentially offset from the second channel. Electronics enclosures and methods of venting electronics assemblies are also described.

Abstract: A base plate for an ostomy appliance is disclosed, the base plate comprising a first adhesive layer with a proximal side configured for attachment of the base plate to the skin surface of a user, the first adhesive layer having a stomal opening with a center point; and a plurality of electrodes including a ground electrode, a first electrode, and a second electrode, the ground electrode comprising a ground connection part, the first electrode comprising a first connection part, and the second electrode comprising a second connection part; wherein the ground electrode forms a ground for the first electrode and the second electrode.

Abstract: A reciprocating compressor is provided. The reciprocating compressor may include a cylinder having a compression space, a piston inserted into the cylinder to define the compression space while being reciprocated, the piston having a suction passage to communicate with the compression space, a gas bearing having at least one bearing hole that passes through the cylinder, so that a refrigerant gas may be injected between the cylinder and the piston to support the piston with respect to the cylinder, and a flow resister disposed at an outer circumferential surface of the cylinder or at one side of the cylinder to restrict a flow of the refrigerant gas flowing through or toward the at least one bearing hole.

Abstract: A base plate for an ostomy appliance is disclosed, the base plate comprising a first adhesive layer with a proximal side configured for attachment of the base plate to the skin surface of a user, the first adhesive layer having a stomal opening with a center point; and a plurality of electrodes including a ground electrode, a first electrode, and a second electrode, the ground electrode comprising a ground connection part, the first electrode comprising a first connection part, and the second electrode comprising a second connection part; wherein the ground electrode forms a ground for the first electrode and the second electrode.

Abstract: A base plate of an ostomy appliance includes a first adhesive layer and a masking element. The first adhesive layer includes a stomal opening with a center point and a proximal surface configured to be attached to a skin surface of a user. The masking element is arranged on a distal surface of the first adhesive layer and is more insulative than the first adhesive layer. A plurality of electrodes is arranged on the distal surface of the first adhesive layer, where each electrode includes a sensing part and a conductor part. The masking element is arranged between the conductor part of each electrode and the first adhesive layer. The electrodes are formed on a proximal surface of a support layer.

Abstract: A ventilation member includes: a cylindrical holding member including an outer projection portion; a ventilation film mounted to cover one end of the holding member in a centerline direction, the ventilation film preventing a liquid and solid from entering the holding member, the ventilation film permitting a flow of gas between the inside and the outside; and a cover member provided around the holding member, the cover member including a side wall portion, a top portion, and an inner projection portion, the top portion closing one end of the side wall portion in the centerline direction, the inner projection portion projecting inward from an inner circumferential surface of the side wall portion and contacting the outer projection portion of the holding member so as to form a ventilation passage between the ventilation film and the top portion, the ventilation passage allowing gas to flow therethrough.

Abstract: A method of processing a fluid produced from a well, the produced fluid being a high pressure fluid, the method comprising: reducing the pressure of the fluid to a reduced pressure such that a gas phase and a liquid phase are formed; separating the gas phase from the liquid phase thus forming a gas product and a liquid product; and storing the liquid product in a storage tank at a pressure such that the liquid product remains in a stable liquid phase during storage, wherein the reduced pressure is greater than atmospheric pressure.

Abstract: An ostomy pouch vent includes a venting portion and a closure portion. The venting portion includes a cylindrical vent body defining a through-opening passage though the body. The closure portion including a closer body that is adapted to engage the vent body to selectively close the through-opening and a support member supporting the closure body. The support member manipulates the closure body into registration with the vent body to close the through-opening and manipulating the closure body away from the vent body to open the through-opening. A pair of grasping members extends in generally opposite directions from the support member. The grasping members have a grasping surface configured to be engaged by fingers of a user to apply a force to the support member.

Abstract: Hydrophobic filter materials, methods of making them, and their use in various industrial applications are presented. In an example, thermally stable, gas permeable hydrophobic filters which maintain their integrity upon exposure to elevated temperature, radiation, acid, or all are described.

Abstract: The present invention provides a closure for a hot-fill container comprising: a cap member having a top surface, a bottom surface, and a wall portion having an outer surface and an inner surface wherein the inner surface comprises threads to mate with a threaded neck finish of a hot-fill container; a flexible diaphragm member comprising: at least one flexible portion in a first position and a sealing lip portion to seal a liquid in the container thus preventing the liquid from traveling to the threaded neck finish of the container; and a disc member interposed between the cap member and the diaphragm member, wherein the disc member comprises: a hydrophobic filter membrane and at least one vent providing a path for air to travel from an area near the threads to the hydrophobic filter member, wherein the flexible diaphragm member flexes to compensate for a change in pressure within the container by transitioning downwards in response to a decrease in pressure and/or by transitioning upwards in response to an in

Abstract: A vent cap has a cap wall extending an inner surface of a cap base. First and second sealing lips extend starting from the cap base. Each sealing lip has at least one cutaway such that two adjacent cutaways are offset with respect to each other. A vent body has a plate with an opening formed therethrough. Inner and outer guide walls extend vent body plate and at least partially encircle the ventilation opening. The cap base lies flush against an outer wall of the vent body such that the first and second sealing lips lie flush against the outer wall of the vent body to form a flow path with a first labyrinthine course in a radial direction and a second labyrinthine course in a vertical direction between the vent body plate and the base body.

Abstract: Disclosed is a computer containing electronic components incorporating a liquid-tight and gas-permeable ventilator, including, on a part of the computer, a unit for protecting the ventilator against liquid spraying, which is created by stamping sheet metal making up the part receiving the ventilator, the protection unit being placed on one of the edges of the sheet metal part and then being folded onto the ventilator in order to make up, for the latter, a shield against liquid spraying. Also disclosed is the associated method.

Abstract: An ostomy bag including in an accessible wall 1 a closable exit aperture 5 and means 4 for selectively releasing accumulated gas through the aperture 5.

Abstract: An inlet bleed heat (IBH) system manifold for a compressor inlet housing is provided. The manifold includes: a plurality of feed pipes for delivering a compressor discharge air, each feed pipe extending across a duct of the compressor inlet housing. Each feed pipe includes: an elongated inner feed pipe for delivering the compressor discharge air, the inner feed pipe including a plurality of orifices along at least a portion of a length of the inner feed pipe, each orifice extending through a wall of the inner feed pipe allowing the compressor discharge air to exit the inner feed pipe; and a noise attenuating material disposed about the inner feed pipe and the plurality of orifices, the noise attenuating material configured to attenuate noise created by the compressor discharge air exiting the plurality of orifices.

Abstract: The ventilation member of the present invention includes: a support having a through hole serving as a part of an air passage between an interior space and an exterior space of a housing when the support is attached to an opening of the housing; an air-permeable membrane disposed on the support to cover one end of the through hole that opens into the exterior space; and a cover member covering the support over the air-permeable membrane so as to form, between the cover member and the support, a ventilation space serving as a part of the air passage. The support includes a first oil-repellent portion formed around the air-permeable membrane. The first oil-repellent portion is formed by oil-repellent treatment of a part of a first surface of the support. The present invention provides a ventilation member suitable for preventing adhesion of oil to the air-permeable membrane even if the oil enters the inside of the cover member.

Abstract: A ventilation member of the present invention includes: a support having a through hole serving as an air passage between an interior space and an exterior space of a housing when the support is attached to the opening of the housing; a filter member disposed on the support to cover an aperture of the through hole that opens into the interior space; and an air-permeable membrane disposed on the support to cover an aperture of the through hole that opens into the exterior space. The through hole includes: a first air passage extending in a predetermined direction from one end of the first air passage to the other end of the first air passage, the one end forming the aperture that opens into the interior space; a second air passage having one end connected to a side of the first air passage and the other end forming the aperture that opens into the exterior space; and a dead end passage extending in the predetermined direction from the other end of the first air passage.

Abstract: Disclosed is an automatic gas intake and exhaust valve device including a main body part having an orifice hole at one side and an intake and exhaust hole at an opposite side, an opening/closing member movably inserted into the main body part to open/close the intake and exhaust hole, and a coupling member extending along one side of the main body part to couple the main body part with a pipe in the communication state of the pipe. The opening/closing member floats according to a flow velocity of a fluid introduced into the main body part and discharged out of the main body part, to close the intake and exhaust hole, and drops down to the bottom of the main body part by a weight of the opening/closing member to open the intake and exhaust hole if a fluid level is lowered, thereby automatically introduce and exhaust internal air of the pipe and facilities.

Abstract: An emissions device for use with a container assembly with a vent opening is provided. The emissions device includes a housing configured to be mounted to the container. The housing includes a backing plate that has at least one opening. A membrane is supported by the backing plate and extends over the opening. The membrane is configured to allow passage of vapor and prevent passage of liquid. A filter is located within the housing such that vapor that passes from the at least one opening through the membrane then passes through the filter. At least one spring is positioned within the housing and is configured to compress the filter.

Abstract: A system for ventilating and venting containers containing a fluid volume, such as gearboxes containing an oil filling, has a line system connecting the container to the atmosphere. Upon changes in the volumes in the container due to temperature changes, pressure is equalized. The line system contains a separating housing (12) in which a separating medium (46) having oleophobic and hydrophobic properties separates a first space (42) connected to the container from a second space (44) connected to the atmosphere. Line connections (10, 14) on the separating housing (12) are provided such that liquid-phase substances on opposite sides of the separating medium (46) can flow out of the first space (42) to the container and can drain out of the second space (44) to the atmosphere.

Abstract: A wall ventilation screen to be used in exterior walls of buildings or vehicles for protecting against rain water and other elements while simultaneously enabling air flow. The screen includes a plurality of air passages that enable air flow from one side of the screen to the other but preferably without linear communication between both sides through the air passages. The air passages present an upwardly traveling trajectory from an exterior or exposed space to a protected space, preferably with lateral changes of direction as well. Therefore rain water that comes directly from precipitation or splashing from an adjacent surface cannot reach a protected space. The geometry of the air passages provides protection against other environmental or man made elements.

Abstract: An enclosure has a perforated front door with a replaceable filter, and a perforated rear side allowing air to flow through the enclosure. The enclosure also has mounting brackets for heat generating elements, such as line cards or other rack mounted electronics. A fan draws air through the perforated front door, though the filter, and across the heat generating elements. Side brushes are disposed on a side wall near the front of the enclosure, which allow any cables attached to the heat generating elements to exit the enclosure. The front door is removable, opening up one side of the side brushes and allowing the cables to slide in the side brushes while still connected to the heat generating elements.

Abstract: An air and moisture separator for use with a waste tank and a vacuum source has a canister securable to the waste tank and having an inlet couplable to the waste tank and an outlet couplable to the vacuum source. An air flow path extends through the canister and through at least three different stages of air and moisture separation, including: a first air-turning stage coupled to the inlet; and a second stage of mesh or foam coupled to and subsequent to the first air-turning stage in the air flow path. An annular mesh or foam of greater density defines a third stage subsequent to the second stage, and circumscribes at least a majority of a circumferential perimeter of the mesh or foam of the second stage.

Abstract: A venting device for a housing, for example, a battery housing, has a gas-permeable and liquid-impermeable membrane attached to the housing so as to close off a venting opening of the housing. The membrane has a membrane section that overlaps and covers the venting opening. The membrane section has a predetermined bursting pressure. The membrane section deforms without being destroyed when pressure differences between the interior of the housing and the environment occur that are below the bursting pressure and when gas passes through the membrane section.

Abstract: The ventilation member of the present invention includes a waterproof gas permeable membrane (11), and a support body (12) having a through hole (13). One opening of the through hole (13) is closed by the gas permeable membrane (11). The support body (12) includes, at an edge of the opening closed by the gas permeable membrane (11), a first region and a second region facing each other with the opening located therebetween. A first angled protrusion (12a) in which a peak and a trough are arranged alternately along the edge of the opening is provided in the first region, and a second angled protrusion (12b) in which a peak and a trough are arranged alternately along the edge of the opening is provided in the second region.

Abstract: A filter system for an explosion-proof enclosure is described herein. The filter system can include a pre-filter assembly located outside the explosion-proof enclosure. The pre-filter assembly can include a pre-filter material configured to control air passing therethrough. The filter system can also include a filter assembly coupled to the pre-filter assembly. The filter assembly can further control the air received from the pre-filter assembly and passing therethrough into the explosion-proof enclosure.

Abstract: A housing (10) is provided with an opening (11) having a tapered surface (12). A vent member (2) to be attached to the opening (11) includes a support body (3) having a vent passage (30), a waterproof gas-permeable membrane (4), and a cover (5). The support body (3) has a base portion (31) to which the waterproof gas-permeable membrane (4) is bonded, and a stem portion (32) extending from the base portion (31) so as to be engaged with an inside surface of the housing (10). The stem portion (32) is fitted with a seal member (6), and this seal member (6) is pressed against the tapered surface (12) in the opening (11) by a pressing portion (34).

Abstract: An adaptable emission filtration, monitoring, and notification system for emission sources within a civic infrastructure has a filter housing with filtration media located inside. The system has a control system with a filter intake sensor, a filter discharge sensor, a microprocessor, a power source, and a transmitter. The system has a civic reception system located in a geographically bound area of interest, with a receiver. The filter housing intake side is attached to an emission source discharge opening. The filtration media filters toxic emissions from the gas stream. The microprocessor compares the signal from the filter intake sensor and the filter discharge sensor then sends a resultant signal by way of a transmitter to the receiver of the civic reception system upon detected decreased efficiency of the filtration media.

Abstract: A polar cap for a vacuum waste tank includes an annulus with a lower outer mounting flange and an upper inner mounting flange surrounding a separator opening configured to be coupled to a separator; an inlet opening disposed in the annulus configured to be coupled to a waste line; and another opening disposed in the annulus configured to be coupled to a sensor or a rinse nozzle. The cap can carry sensors, rinse nozzles, inlets, and diverts.

Abstract: Vents for containers include a perforated substrate portion (20) of polymer material over which is thermally bonded a gas permeable membrane (30). The thermal bond (31) is direct and adhesive-free so that there is no adhesive available for chemical attachment by materials within the containers (58) and no opportunity for an adhesive to interfere with or block perforations through the substrate.

Abstract: An avionic bay with a device for filtering cooling air for aircraft electrical equipment. The device includes at least two filtration grilles provided with apertures and which are disposed successively one behind the other in order to filter the air drawn from a cooling air vein before distributing it to an aircraft electrical equipment item. The apertures of the second grille are offset transversely in relation to the apertures of the first grille.

Abstract: An object is to provide a vent plug having a structure in which an air-permeable membrane is unlikely to be damaged. More specifically, a vent plug is produced, which includes: a cylindrical member 1 having a through-hole 1a; a support 2 connected to the cylindrical member 1 so as to be across the through-hole 1a; and an air-permeable membrane 3 circumferentially attached to the cylindrical member 1, wherein the air-permeable membrane 3 is held on the support 2 and a convex portion 3a that follows the shape of the support 2 is formed on the air-permeable membrane 3.

Abstract: A ventilation member 13 includes a gas-permeable sheet 6 and a support body 11 in which a through-hole 11h is formed. One opening of the through-hole 11h is closed by the sheet 6. As a face to which the sheet 6 is to be attached, the support body 11 has a ring-shaped opening end face 12 parallel to the in-plane direction of the sheet 6. In an outer peripheral region 12j of the opening end face 12, the sheet 6 is welded to the support body 11, forming a ring-shaped welded portion 15. The sheet 6 is not welded to the support body 11 in an inner peripheral region 12k of the opening end face 12. The inner peripheral region 12k is surrounded by the welded portion 15.

Abstract: A ventilation member (100) of the invention includes a tubular part (11), a gas permeable filter (19), and a cover part (31). In an attached state where the tubular part (11) is fit into the cover part (31), gaps functioning as gas passages (AR2 and AR3) are formed between a bottom portion (35) of the cover part (31) and the gas permeable filter (19) and between a side wall portion (39) of the cover part (31) and a body portion (17) of the tubular part (11). The opening area (S2) of a filter-end opening (15) with respect to an in-plane direction (WL) perpendicular to the thickness direction of the gas permeable filter (19) is larger than the opening area (S1) of a connection-end opening (13) with respect to the in-plane direction (WL).

Abstract: A self-contained breathing closure for flasks and other containers that require gas exchange. An illustrative embodiment of the closure is comprised of a splashguard, an adaptor for attaching the closure to the container, a bellows element and a gas-permeable barrier element. The splashguard is intended to keep liquid contents under vigorous agitation in the container without wetting the gas-permeable barrier. The adaptor couples the closure to the container in a secure fashion. The bellows element allows for repeated changes in the internal volume of the container-closure system. The gas-permeable barrier allows desired gases to enter and leave the container while excluding small particles and/or microorganisms. The technology may be used with existing glass flask technology, or coupled to a plastic flask that may be configured for either single-use, or multiple-use.

Abstract: It is an object to provide a vent filer that can reduce contaminants diffusing through the vent filter into the inside of a housing, and has high diffusion efficiency and low pressure loss. The vent filter has an adhesive layer 1 having a through-hole 1a at least in one area; a flow path member 2 provided with a flow path 2a in communication with the through-hole 1a; and an air-permeable membrane 3 covering the flow path member 2 and part of the adhesive layer 1, wherein the peripheral portion 3a of the air-permeable membrane 3 is fixed to the adhesive layer 1 and the flow path member 2 is held within a hollow portion formed between the adhesive layer 1 and the air-permeable membrane 3.

Abstract: A battery fire prevention device includes a lithium battery, a container, and a porous material. The container houses the lithium battery and has an outwardly interfacing wall with an aperture which extends therethrough to vent outgassed battery constituents generally away therefrom. The porous material is disposed within the container between the aperture and the battery. The porous material is capable of trapping lithium particulates outgassed from the lithium battery within the container.

Abstract: A vent for an axle housing includes a first body portion and a second body portion. The first body portion has a plurality of pores defined therethrough. The first body portion defines a first cavity. The second body portion has a conical portion that extends between a throat and a neck portion that defines an opening. The second body portion defines a second cavity that fluidly connects with the first cavity. The vent permits air to pass from the axle housing, through the plurality of pores in the first body portion, through the first and second cavities, and out the opening of the neck portion while concurrently inhibiting egress of lubricant from the axle housing.

Abstract: An object is to provide a vent filter in which a vent film is less likely to be broken when cut and a measure to shrinkage is taken while the characteristics and functions both inherent to the vent film are being kept. The vent filter includes a frame-shaped adhesive layer 2 and a vent film 3 attached to the adhesive layer 2, wherein an outer peripheral portion of the vent film 3 is positioned at an outer side than an outer peripheral portion of the frame-shaped adhesive layer 2.

Abstract: A system is configured to remove volatile organic compounds from a container. The system includes an enclosed contactor vessel having a first inlet to receive vapor containing volatile organic compounds from the container and a second inlet. The second inlet receives a vapor capture medium from a source. A contactor facilitates entrainment of the volatile organic compounds with the vapor capture medium while a first outlet recirculates treated vapor back to the container to effect a closed loop.

Abstract: A method of using a modular International Organization for Standardization (ISO) filter house for filtering process fluids is provided. The filter house includes a self-contained rectangular cuboid enclosure having the outside dimension of a standard, transportable ISO shipping container. The filter house has apertures for fluid flow inlet and fluid flow outlet, and a filter element for removing impurities from the fluid flow. The method includes creating one standard filter house design to be used in any multiple to meet various flow requirements. The method further includes creating a common fluid connection between the filter houses and process equipment so that the filter houses operate in parallel. A kit of modular components for filtration of a fluid is also provided. The kit includes an external structure of an ISO shipping container, vanes to direct fluid flow, and a filter element.

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: The disclosure relates to a gas permeable wall for preventing dirt present in a gas flow from passing through the gas permeable wall with the gas flow. In order to minimize maintenance, the gas permeable wall is a circumferential wall of a cover, and an outlet from the cover is provided for passing on gas having entered the cover through the circumferential gas permeable wall. A support is provided for attaching the cover rotatably to a device, and a drive unit is provided for rotating the cover.