Separation device and oil separating air filter assembly comprising such separation device as well as method for separating fluid from a gas stream deriving from a connecting device

A separation device for separating fluid from a gas stream has a housing replaceably connected to a connector head of a connecting device. The housing has a housing corpus with an axial end covered by a housing cover non-detachably connected to the housing corpus. A filter insert is received in the housing in a flow path of the gas stream from a raw gas inlet to a clean gas outlet of the housing. The filter insert has a main separator element with ring-shaped support body and cylindrical coalescing filter medium with coalescer material removing fluid from the gas stream. A preliminary separator element is arranged concentrically to the main separator element in the housing in the flow path of the gas stream between raw gas inlet and main separator element. The preliminary separator element has a cylindrical coalescing filter medium with coalescer material removing fluid from the gas stream.

TECHNICAL FIELD

The present invention relates to a separation device, in particular to a spin-on filter, for separating fluid, in particular oil, from a gas stream, in particular from an air stream, for example from a compressed air stream, of a connecting device, in particular of a compressor, of a compressed air system or of a vacuum pump.

BACKGROUND OF THE INVENTION

Prior art document EP 0 814 891 B1 discloses an air de-oiling separator comprising an interchangeable filter insert with a prefiltering web. The interchangeable filter insert comprises a flange for arranging the interchangeable filter in a pressure vessel. In EP 0 814 891 B1 the filter insert by itself is a replaceable unit. This filter insert is designed for being replaceably received in a housing.

In case of spin-on separation devices, as a rule the filter housing cannot be opened, i. e., the housing cover is non-detachably connected to the housing. Thus, the spin-on filter as a whole forms a replaceable unit. The design of a spin-on filter is therefore also referred to as a replacement filter.

A separation device, in particular a spin-on filter, of the aforementioned kind is disclosed in prior art document DE 10 2011 10 80 61 A1. The preliminary separator element of the separation device differs from the separation device of the present invention in that the prior art preliminary separator element acts by changing the gas flow direction due to the preliminary separator element geometry, e. g. blade geometry. According to DE 10 2011 10 80 61 A1 the preliminary separation occurs by inertia of the fluid due to the redirection of the gas flow. The preliminary separator element disclosed in DE 10 2011 10 80 61 A1 is voluminous and expensive to produce.

SUMMARY OF THE INVENTION

The present invention relates to a separation device, in particular to a spin-on filter, for separating fluid, in particular oil, from a gas stream, in particular from an air stream, for example from a compressed air stream, of a connecting device, in particular of a compressor, of a compressed air system or of a vacuum pump.

The separation device comprises a housing being designed to be replaceably connected with the connecting device, in particular to be spinned on the connecting device. A hollow cylindrical filter insert is received in the housing in the flow path of the gas stream between at least one raw gas inlet and at least one clean gas outlet. The raw gas inlet is designed for supplying raw gas or for supplying gas to be separated from fluid. The clean gas outlet is designed for exhausting clean gas or for exhausting separated gas. The raw gas inlet and the clean gas outlet are advantageously arranged at the housing cover.

An axis, in particular an assembly axis for mounting the separation device to the connection device, extends longitudinally through the housing corpus and defines an axial direction. The housing comprises a cup-shaped housing corpus and a housing cover for covering a first axial end of the housing corpus. The housing cover is non-detachably connected to the housing corpus, i. e., the housing cover is connected to the housing corpus in such way that the housing cover cannot be disconnected from the housing corpus without destroying the housing corpus and/or the housing cover.

The filter insert comprises at least one main separator element comprising at least one coalescing filter medium being designed for separating the housing into a raw side and a clean side. The term main separator element is used in the context of this application to mean “filter body” and is to be understood as the part of a filter insert arranged in the housing and producing the main separation effect. The filter insert further comprises a ring-shaped support body for supporting the coalescing filter medium of the main separator element.

The separation device further comprises at least one preliminary separator element being arranged in the housing in the flow path of the gas stream between the raw gas inlet and the main separator element. Thus, the separation device is arranged upstream of the main separator element in the direction of the flow path. The raw gas inlet is arranged at the raw side of the housing and the clean gas outlet is arranged at the clean side of the housing.

The present invention further relates to an oil separating air filter assembly comprising at least one separation device of the aforementioned kind and at least one connecting part, in particular at least one connection nipple or connection tube or threaded pipe stub, being designed for connecting the separation device with a connector head of the connecting device, wherein the connecting part is arranged within the clean gas outlet of the separation device, and wherein the connecting part comprises at least one connecting element, in particular at least one threaded pipe stub, for connecting the separation device with the connector head and at least one clean gas conducting element, in particular at least one nipple or tube, comprising at least one gas-conducting inner space for conducting separated clean gas from the clean side of the separation device to the connector head of the connecting device.

The present invention also relates to a method for separating fluid, in particular oil, from a gas stream, in particular from an air stream, for example from a compressed air stream, deriving from a connecting device, in particular from a compressor, from a compressed air system or from a vacuum pump,(i) wherein the gas stream to be separated from fluid is flowing into a housing of a separation device through at least one raw gas inlet of the housing, the housing being replaceably connectable with a connector head of the connecting device,(ii) wherein in the housing the gas stream is flowing through at least one preliminary separator element being arranged in the flow path of the gas stream between the raw gas inlet and at least one main separator element,(iii) wherein, after passing through the preliminary separator element, the gas stream is flowing radially through the main separator element, the main separator element being arranged in the housing in the flow path of the gas stream between the preliminary separator element and at least one clean gas outlet out of the housing, wherein the main separator element is acting as a coalescer for removing fluid, in particular oil, from the gas stream and separates the housing into a raw side and a clean side.

Starting from the disadvantages and shortcomings as described earlier and taking the prior art as discussed into account, an object of the present invention is to further develop a separation device of the kind as described in the technical field, an oil separating air filter assembly of the kind as described in the technical field, and a method of the kind as described in the technical field in such way that a preliminary separation of the gas stream having streamed into the housing by the raw gas inlet is provided with low costs and low volume. In particular it is an object of the present invention to further develop a separation device of the kind as described in the technical field such that the separation device is designed in a compact manner and is inexpensive and easy to manufacture.

The object of the present invention is achieved by a separation device of the aforementioned kind that, in accordance with the present invention, is characterized in that the preliminary separator element comprises a hollow cylindrical coalescing filter medium comprising at least one coalescer material for removing fluid from the gas stream, wherein the preliminary separator element is arranged concentrically to the main separator element.

The object of the present invention is achieved by an oil separating air filter assembly of the aforementioned kind that comprises, in accordance with the present invention, the separation device embodied in accordance with the present invention.

The object of the present invention is achieved by a method of the aforementioned kind, wherein, in accordance with the present invention, the gas stream is flowing radially through the preliminary separator element, wherein the preliminary separator element is acting as a coalescer for removing fluid, in particular oil, from the gas stream.

Advantageous embodiments and expedient improvements of the present invention are disclosed in the respective dependent claims.

The present invention is principally based on the idea of providing a separation device of the kind as described in the technical field with at least one preliminary separator element comprising at least one coalescing filter medium, in particular at least one preliminary filter mat. The preliminary separator element comprises, in particular consists of, a ring-shaped or hollow cylindrical coalescing filter medium being arranged concentrically or coaxial to the main separator element. The preliminary separator element according to the present invention acts as a coalescer.

The preliminary separator element comprising at least one coalescing filter medium enables that the amount of fluid arriving at the main separator element is reduced or at least exists in a more usable form, e. g. the fluid comprises larger drops and/or the gas stream comprising the fluid to be separated flows through the main separator element with a preferably more uniform flow distribution. This leads to the advantage that the separation device according to the invention has an increased degree of separation.

The coalescing filter medium advantageously essentially comprises nonwoven filter material, in particular nonwoven fabric, for example fibrous nonwoven fabric, such as fibrous nonwoven fabric made of polyester.

According to a preferred embodiment of the present invention, the preliminary separator element has a smaller flow resistance than the coalescing filter medium of the main separator element.

Independently thereof or in combination therewith, according to a preferred embodiment of the present invention the coalescer material of the preliminary separator element has a smaller coating weight per unit area and/or a higher fiber coarseness than the coalescing filter medium of the main separator element.

For the present invention, the main separator element is advantageously designed as a filter wrap, i.e. at least one filter medium, for example non-woven filter material, which is wound a plurality of times about a ring-shaped support body, in particular about a perforated support tube. The coalescer material of the main separator element is advantageously a glass fiber material.

The preliminary separator element and the main separator element are arranged in succession in direction of the flow path. The ring-shaped coalescing filter medium of the preliminary separator element can be, for example, nonwoven filter material. The arrangement of the hollow cylindrical preliminary separator element concentrically to the hollow cylindrical main separator element leads to the advantage that the separation device is designed in a very compact manner.

According to an advantageous embodiment of the present invention, the filter insert comprises at least one first end disc and at least one second end disc disposed on opposite axial end face sides of the filter insert. The first end disc faces the housing cover and the second end disc faces away from the housing cover. The first end disc comprises a radially outer peripheral wall element extending over the main separator element in axial direction. In other words, the radially outer peripheral wall element is surrounding the main separator element. The radially outer peripheral wall element of the first end disc aims for fixing the main separator element to the first end disc. The main separator element can be, for example, fixed to the first end disc by glue being arranged at the side of the first end disc facing the main separator element.

Advantageously, the preliminary separator element is disposed with regard to the axis radially outward from the radially outer peripheral wall element of the first end disc. In other words, the preliminary separator element advantageously overlaps the radially outer peripheral wall element of the first end disc in radial direction. This leads to the effect that the fluid separated by the preliminary separator element passes by the radially outer peripheral wall element of the first end disc and collects at the raw side of the separation device. Thus, the fluid separated by the preliminary separator element does not flow to an area of the filter insert being surrounded by the radially outer peripheral wall element of the first end disc and consequently does not flow into the clean side of the separation device. By disposing the preliminary separator element with regard to the axis radially outward from the radially outer peripheral wall element of the first end disc, the overall performance of the separation device can be increased.

The housing advantageously comprises at least one raw side collecting area for collecting, under the influence of gravity, fluid being separated by the preliminary separator element. The raw gas inlet is advantageously designed in such way that fluid being collected at the raw side collecting area flows under the influence of gravity through at least one fluid outlet being arranged at the raw side of the housing, in particular through the raw gas inlet, out of the separation device. This leads to the advantage that the separated fluid can directly drop back into the original room where it derives from. Surprisingly, only an insignificant part of the separated fluid is reabsorbed by the flow path and the re-entrainment of the fluid collected in the raw side collecting area is insignificantly low. Thus, the separation efficiency of the separation device is increased, the gas stream flowing through the raw side collecting area notwithstanding.

After having passed the raw gas inlet, the fluid may enter a fluid chamber of the connecting device.

The separation device is advantageously designed such that the fluid level of the fluid collected in the raw side collecting area is arranged geodetical below the first end disc.

The housing advantageously comprises at least one clean side collecting area for collecting, under the influence of gravity, fluid being separated by the main separator element. The fluid being collected at the clean side collecting area is advantageously flowing out of the separation device, under the influence of gravity, air flow and/or local pressure difference, through at least one fluid outlet being arranged at the clean side of the housing, in particular at the clean gas outlet.

Independently thereof or in combination therewith, according to a preferred embodiment of the present invention the second end disc comprises a radially outer peripheral wall element surrounding the preliminary separator element and extending over the preliminary separator element in axial direction. In other words, the preliminary separator element can be disposed with regard to the assembly axis radially inward from the radially outer peripheral wall element of the second end disc. This leads to the advantage that the second end disc can be used for fixing the preliminary separator element at the filter insert. For example, the preliminary separator element can be fixed to the second end disc by means of glue being arranged at the side of the second end disc facing the preliminary separator element. In combination with the glue connection or as an alternative thereto, the preliminary separator element can be fixed to the second end disc by means of at least one clamping connection, for example, by means of at least one flare joint.

The preliminary separator element can be arranged detachably, for example loose, at the radially outer peripheral wall element of the first end disc.

Advantageously the preliminary separator element abuts against the radially outer peripheral wall element of the first end disc in such way that it is elastically fixed at the radially outer peripheral wall element of the first end disc. In particular the preliminary separator element can tightly fit with slight tension on the radially outer peripheral wall element of the first end disc. For example, the preliminary separator element can cover the first end disc like a stocking or a sock.

Alternatively, the preliminary separator element can be fixed to the radially outer peripheral wall element of the first end disc non-detachably, for example, by means of glue.

The raw gas inlet is arranged at the raw side of the housing and the clean gas outlet is arranged at the clean side of the housing. According to an advantageous embodiment of the invention, the raw gas inlet and/or the clean gas outlet are arranged at the housing cover.

The preliminary separator element is advantageously arranged concentrically to the main separator element and is configured to be flowed through radially by the gas stream or by the flow path.

In order for the raw gas having streamed into the housing via the raw gas inlet to distribute essentially over the whole axial length of the housing inside and to stream into the preliminary separator element at an area that is optimal for the flow path depending on decrease in pressure, according to an advantageous embodiment of the present invention, there is a gap between the radial wall of the housing corpus and the preliminary separator element.

For connecting the separation device with the connecting device, the housing cover is advantageously designed to be replaceable mounted onto a connecting part. In particular the housing cover comprises a central hole being designed for passing through the connecting part, wherein the connecting part comprises at least one connecting element being replaceably connectable with the separation device as well as with the connector head, and at least one clean gas conducting element for conducting clean gas from the separation device to the connector head. For example, the clean gas outlet can be a central threaded hole of the housing cover, wherein the threaded hole is designed to be screwed onto a threaded pipe stub firmly fixable on a connector head of the connecting device.

The oil droplets having been separated by the main separator coalescing element and the oil droplets having been separated by an optional secondary separator element flow downward following gravity, working pressure and/or vacuum and pass advantageously through at least one coaxial fluid outlet of the connecting part into at least one oil outlet channel of the connector head.

The present invention in particular relates to the use of at least one separation device as described above and/or of at least one oil separating air filter assembly as described above and/or of the method as described above for separating oil from a compressed air stream deriving from a compressor, from a compressed air system or from a vacuum pump.

The same reference numerals are used for corresponding parts inFIG. 1toFIG. 6.

DESCRIPTION OF PREFERRED EMBODIMENTS

In order to avoid unnecessary repetitions, the following description regarding the embodiments, characteristics, and advantages of the present invention relate to (unless stated otherwise)the first embodiment of the oil separating air filter assembly according to the present invention (cf.FIGS. 1 to 4) as well asthe second embodiment of the oil separating air filter assembly according to the present invention (cf.FIG. 5) as well asthe first embodiment of the separation device100according to the present invention (cf.FIGS. 1 to 4) as well asthe second embodiment of the separation device100′ according to the present invention (cf.FIG. 5),
all embodiments100,100′ being operated according to the method of the present invention.

FIG. 1shows a first embodiment of an oil separating air filter assembly according to the present invention, serving for the separation from the air of such oil as is carried with the air. The oil separating air filter assembly is used, for example, in compressors, vacuum pumps compressed air systems or the like. It can be disposed before the inlet or after the outlet of a corresponding unit.

The oil separating air filter assembly depicted inFIG. 1comprises a first embodiment of the separation device100according to the present invention, which can also be referred to as a spin-on air de-oiling box or an air/oil separator box. The spin-on air de-oiling box100is replaceably fixed on a connector head200, at the bottom ofFIG. 1. The connector head200serves as a connection element for corresponding air lines and oil lines for connecting with a corresponding connecting device, in particular with a compressor, with a compressed air system or with a vacuum pump.

A connecting part300,310, in particular a connection nipple or connection tube, for example, of a threaded pipe stub or threaded connection nipple or threaded connection tube, such as a hollow, pipe stub-like connection nipple300,310, connects the spin-on air de-oiling box100with the connector head200. The connection nipple300,310comprisesa connecting element300, in particular a threaded pipe stub, for connecting the separation device100,100′ with the connector head200anda clean gas conducting element310, in particular at least one nipple or tube, comprising at least one gas-conducting, in particular air-conducting, inner space.

The spin-on air de-oiling box100comprises a housing with a cup-shaped corpus18and a housing cover16for closing an opening of the housing corpus18. The housing corpus18and the housing cover16are made, for example, of metal. Alternatively, at least one of the two components can be made from another material, for example, plastic, or at least have another material.

A hollow cylindrical filter insert20is disposed in the housing16,18in the flow path of the gas stream between at least one raw gas inlet30and at least one clean gas outlet32. The filter insert20is configured to be flowed through radially by the gas stream as depicted inFIGS. 3 and 6. The filter insert20comprises a main separator element22,23designed as a ring-shaped coalescing element. The main separator element comprises a coalescing filter medium23and a ring-shaped support body22for supporting the coalescing filter medium23. By way of example, the main separator element has as a filter medium a glass fiber mat23, which is repeatedly annularly wrapped and bounded by a first end disc or by a lower end plate24facing the connector head200and a second end disc26or an upper end plate26facing away from the connector head200.

As a secondary separator element28(cf.FIGS. 2 and 3) a further filter medium, for example, a non-woven material, can be disposed in the interior of the glass fiber wrap23of the main separator element of the filter insert20.

The filter insert20moreover comprises a preliminary separator element40(cf.FIGS. 1 to 5) comprising a coalescing filter medium, namely a non-woven filter material or a mat, for example, a glass fiber mat40. The mat40can be repeatedly annularly wrapped and bounded by the upper end plate26.

In the assembled state shown inFIGS. 1 to 5, the radially outer circumferential side of the preliminary separator element40is spaced apart from the radially inner circumferential side of the housing corpus18such that an annular gap42arises between the corresponding circumferential sides as a passage for the raw gas.

In general, the spin-on air de-oiling box100,100′,100″ is ready for use as disposed in the orientation shown inFIGS. 1 to 6. It can, however, also be disposed in other orientations. When further reference is made to “below,” “above,” or similar, this refers unless otherwise stated to the representation inFIGS. 1, 2, 3, 5 and 6.

In an operation-ready assembly, the housing corpus18, the filter insert20, and the connection nipple300,310are respectively coaxial with an imaginary assembly axis50. The spin-on air de-oiling box100,100′,100″ can be screwed onto the connector head200and unscrewed therefrom about the assembly axis50by means of the connecting element300of the connection nipple300,310.

When in this document reference is made to “radial,” “axial,” “coaxial”, “concentrically” or “circumferential” or the like, this refers to the assembly axis50, unless stated otherwise.

The lower end plate24facing the housing cover16is approximately annular. It has a coaxial pass-through opening29(cf.FIGS. 2 and 3) for the connection nipple300,310. Radially between the pass-through opening29and the secondary separator element28of the filter insert20, the lower end plate24is repeatedly bent such that there is a circumferential annular trough24a, which opens toward the element interior21of the filter insert20. The trough24acan serve as a clean side collecting area12for collecting, under the influence of gravity, fluid being separated by the main separator element.

The radially inner edge of the lower end plate24surrounds the pass-through opening29. It points toward the element interior21.

The connecting part300,310comprises a connecting element300and at least one clean gas conducting part310. An inner diameter of the connecting element300is larger than an outer diameter of the clean gas conducting part310. Between the radially outer peripheral wall of the clean gas conducting part310and the radially inner edge of the connecting element300, an annular, coaxial fluid outlet34, for example, a passage gap, remains for the oil separated by the main separator coalescing filter medium23and/or by the secondary separator element28.

The raw gas inlet30serves as outlet for the oil being separated by the preliminary separator element40.

The interior of the connection nipple300,310extends through the clean gas outlet32of the housing cover16, thus co-defining the course of the air outlet opening32in the assembled state. The interior of the clean gas conducting part310forms or bounds the effective flow cross section of the clean gas outlet opening32of the housing cover16.

The raw gas inlet30comprises at least two raw gas inlet holes30which pass through and which are arranged radially outside of an assembly opening17(cf.FIGS. 1 to 3) of the housing cover16. Imaginary axes of the raw gas inlet holes30can extend, for example, parallel to the assembly axis50.

The housing cover16is held on the housing corpus18by means of a retaining ring52. The retaining ring52is connected by means of a flared connection54with the edge of the housing corpus18.

The axial outside25of the lower end plate24bounded by the annular trough24aextends over the main separator element filter medium23in the axial direction.

A bottoming of the annular trough-forming section24aof the outside of the lower end plate24sits peripherally connected in the axial direction to a damping ring56(cf.FIGS. 1 and 3). The damping ring56is supported on the axially opposite side on an inner side of the housing cover16. The damping ring56is coaxial with the assembly axis50. It serves inter alia to reduce noise as a so-called rattle guard. It restricts the axial movability of the filter insert20in the housing16,18and thus prevents rattling noises. The damping ring56can further serve as tolerance compensation and/or as damping for operational vibrations or oscillations.

The housing cover16is substantially circular. It is coaxial with the assembly axis50. In its center, the housing cover16has a coaxial assembly opening17(cf.FIGS. 1 to 3) for the connection nipple300,310. A radially inner peripheral wall of the housing cover16surrounding the assembly opening17is equipped with an inner thread. The inner thread mates with a corresponding outer thread on the radially outer peripheral side of the connecting element300of the connection nipple300,310.

During operation of the separation device100,100′, air, which can be loaded with oil droplets, flows from an air inlet line of the connector head200through the air inlet holes30, indicated by an arrow92inFIGS. 2, 3 and 6, into an inlet chamber of the housing (16,18). The lower part of the inlet chamber is located in the housing (16,18) between the lower end plate24and the housing cover16and extends circumferentially radially outward about the filter insert20.

The air flows through the filter medium of the preliminary separator element40from radially outward to radially inward, indicated by arrow94(cf.FIGS. 2, 3 and 6).

The oil droplets are particularly deposited on the radially inner circumferential side of the preliminary separator element40as well as on the radially outer circumferential side of the radially outer peripheral wall element25of the lower end plate24. These oil droplets flow downward following gravity and collect at a raw side collecting area14.

The separated oil droplets collected in the raw side collecting area14pass through the raw gas inlet30, indicated inFIGS. 1 to 3 and 5by dashed arrows98, into an air/oil outlet channel222(cf.FIGS. 1 and 5) of the connector head200.

Alternatively (not shown) the separated oil droplets can flow to an oil outlet channel220of the connector head200via the clean side collecting area12and the coaxial fluid outlet34of the connection nipple300,310. In this alternative embodiment, there is a bypass-connection, for example, by means of openings58of the first end disc24, as depicted inFIG. 6, between the raw side collecting area14and the clean side collecting area12.

In the spin-on air de-oiling box100,100′ depicted inFIGS. 1 to 5, the pretreated air flows through the filter medium23of the main separator element as well as through the filter medium of the secondary separator element28. The oil droplets having been separated by the main separator coalescing element23and the oil droplets having been separated by the secondary separator element28flow downward following gravity and collect at the clean side collecting area12.

The oil droplets collected in the clean side collecting area12pass through the coaxial fluid outlet34of the connection nipple300,310and into the oil outlet channel220of the connector head200. The separated oil droplets can flow, for example, to the oil outlet channel220of the connector head200viathe coaxial fluid outlet34of the connection nipple300(cf.FIGS. 1, 5, 6) orthe inner thread of the radially inner peripheral wall of the housing cover16surrounding the assembly opening17(not shown) orat least one oil outlet hole (not shown) of the housing cover16.

The air, free of oil droplets, flows in the clean air side through the central air outlet opening320in the inner space of the nipple310out of the separation device100,100′ and enters an air outlet channel210of the connector head200.

The gas having been supplied to the oil separation device100,100′ depicted inFIGS. 1 to 5is guided within the housing16,18of the separation device100,100′ first through the preliminary separator element40. Thus, the main separator element is supplied with pre-filtered gas. This leads to the advantage that the residual oil content of the clean air is highly decreased compared to oil separation devices without preliminary separator element.

The second embodiment of the separation device100′ according to the present invention (cf.FIG. 5) differs from the first embodiment of the separation device100according to the present invention (cf.FIGS. 1 to 4) only in that it additionally comprises a further preliminary separator element44. This further preliminary separator element44is arranged in the flow path of the gas stream between the raw gas inlet30and the preliminary separator element40, in particular between the housing cover16and the first end disc24. The fluid being separated by the preliminary separator element40and/or by the further preliminary separator element44drains through the further preliminary separator element44and then flows via the raw gas inlet30back to the connector head200, especially to raw gas inlet222.

The second embodiment of the oil separating air filter assembly depicted inFIG. 5differs from the first embodiment of the oil separating air filter assembly depicted inFIG. 1only in that it comprises the second embodiment of the separation device100′ instead of the first embodiment of the separation device100.

FIG. 6shows an oil separating air filter assembly100″ according to prior art without preliminary separator element.

REFERENCE NUMBERS

12clean side collecting area for collecting, under the influence of gravity, fluid being separated by the main separator element22,23and/or by the secondary separator element28, wherein the clean side collecting area is arranged inside the housing16,18at a geodetic lower area and is arranged at the clean side of the housing16,1814raw side collecting area for collecting under the influence of gravity fluid being separated by the preliminary separator element40, wherein the raw side collecting area is arranged inside the housing16,18at a geodetic lower area and is arranged at the raw side of the housing16,18, in particular is arranged at an inner side of the housing cover16being arranged at the raw side of the housing16,1816housing cover or lid, in particular threaded plate, for example, threaded cover plate17assembly opening of the housing cover18cup-shaped or cylindrical corpus or housing vessel of the housing of the separation device10020cylindrical filter insert21element interior of the filter insert20.22ring-shaped support body of a main separator element23hollow cylindrical or ring-shaped coalescing filter medium of the main separator element, in particular made of glass fiber24first end disc or lower end plate of the cylindrical filter insert2024aannular trough of the first end disc2425radially outer peripheral wall element of the first end disc24or axial outside of the first end disc2426second end disc or upper end plate of the cylindrical filter insert2027radially outer peripheral wall element of the second end disc2628further filter medium of the filter insert20, in particular secondary separator element (cf.FIGS. 3, 4)29pass-through opening of the first end disc24(cf.FIGS. 2, 3)30raw gas inlet32clean gas outlet34fluid outlet for fluid being separated by the coalescing filter medium of the main separator element22,23and/or of the secondary separator element2840preliminary separator element, in particular hollow cylindrical coalescing filter medium, for example, hollow cylindrical mat of fibers or fibrous nonwoven fabric, for example made of polyester, the preliminary separator element being arranged concentrically to the main separator element22,2342gap between the radial wall of the housing corpus18and the preliminary separator element40, in particular annular gap between housing corpus18and preliminary separator element4044further preliminary separator element, in particular mat of fibers or fibrous nonwoven fabric, for example, made of polyester, the further preliminary separator element being arranged in the flow path of the gas stream between the raw gas inlet30and the filter insert20, in particular being arranged between the housing cover16and the first end disc24(cf.FIG. 5)50axis, in particular an assembly axis, extending longitudinally through the housing corpus1852retaining ring for holding the housing cover16on the housing corpus1854flared connection56damping ring58openings of the first end disc24(cf.FIG. 6)92gas inlet flow93gas flow through the further preliminary separator element44(cf.FIG. 5)94gas flow through the filter insert2098dashed arrow indicating separated oil droplets collected in the raw side collecting area14passing through the raw gas inlet30(cf.FIGS. 1 to 3)100separation device of the first embodiment (cf.FIGS. 1 to 4), in particular spin-on separation device or spin-on filter or air de-oiling element or air/oil separator box or air/oil separator element, for separating fluid, in particular oil, from a gas stream, in particular from an air stream, for example from a compressed air stream, of a connecting device100′ separation device of the second embodiment (cf.FIG. 5), in particular spin-on separation device or spin-on filter or air de-oiling element or air/oil separator box or air/oil separator element, for separating fluid, in particular oil, from a gas stream, in particular from an air stream, for example, from a compressed air stream, of a connecting device100″ separation device according to prior art (cf.FIG. 6)200connector head of a connecting device, in particular of a compressor, a compressed air system or a vacuum pump210air outlet channel of the connector head220oil outlet channel of the connector head200for oil being separated by the filter medium23of the main separator element and/or by the secondary separator element28, in particular first oil outlet channel of the connector head200222raw gas inlet and oil outlet channel of the connector head200for oil being separated by the preliminary separator element40and optionally by the further preliminary separator element44222″ raw gas inlet of the connector head200of the separation device100″ according to prior art300connecting element, in particular threaded pipe stub, for connecting the separation device100,100′ with the connector head200310clean gas conducting element, in particular nipple or tube, for conducting clean gas from the separation device100;100′;100″ to the connector head200of the connecting device320central air outlet opening of the clean gas conducting element310