Liquid separator device for a compressor system and compressor system with such a liquid separator device

Description

[0001] The present invention relates to a liquid separation device for a compressor system and to a compressor system with such a liquid separation device.

[0002] In oil-lubricated compressors, such as oil-lubricated screw compressors, the oil used for lubrication and cooling is separated after the compression process via suitable oil separators to prevent it from entering downstream compressed air systems. The separated oil is then returned to the compressor, for example, to the screw block in oil-lubricated screw compressors.

[0003] In current state-of-the-art configurations of such compressor systems, the compressed oil-air flow in oil-lubricated screw compressors encounters a coalescing filter. On the clean side of this filter, the separated oil is drawn off to the injection point on the screw block via the pressure differential. The oil separator forms an integral part of the compressor housing and is directly integrated within it. Return to the screw block is achieved via an external return line that must be routed around the compressor housing. This external return line not only requires considerable installation space but must also be removed for maintenance.

[0004] In this context, US 2004 / 065110 A1 concerns a compression system comprising a motor-driven compressor, an optional accumulator, a liquid / gas separator, a heat exchanger in the form of a condenser and an evaporator, expansion valves, and lines in the form of pipes for connecting these components.

[0005] US 2013 / 255308 A1 concerns a refrigerant circuit that uses a vapor compression cycle. The circuit includes a lubricated compressor connected to an oil separator tank separate from the compressor.

[0006] The JP H08 159581 A relates to an oil separator of a screw refrigeration machine which is integrated into an oil tank, wherein a separating plate preventing lifting for separated refrigeration machine oil is fitted above the oil tank.

[0007] US 2016 / 375390 A1 relates to a horizontal gas coalescing filter unit with a reduced vertical footprint. The gas coalescing filter unit comprises a first housing with an inlet and an outlet, the inlet being configured to receive a pressurized gas, including liquid condensates. A second housing is in liquid communication with the horizontal housing.

[0008] To prevent oil from flowing back into the coalescing filter when the compressor is switched off, a check valve is installed in the return line. Additionally, a nozzle must be installed in the return line to limit air losses from the compressor, as the clean side of the coalescing filter contains predominantly air and relatively small amounts of oil. Because the check valve and nozzle are located in the external return line, they are exposed to varying ambient temperatures, meaning that, for example, at low temperatures, there is a risk of the check valve and / or nozzle freezing.

[0009] Furthermore, the oil extraction on the clean air side of the coalescing filter must be achieved via an additional riser pipe. This arrangement creates the risk of a continuous air leak. Additionally, residual oil may remain below the immersion tube and enter the compressed air system.

[0010] In view of the foregoing, the object of the present invention is therefore to provide a liquid separation device that is improved compared to the prior art, particularly with regard to liquid recirculation that is as low-loss, cost-effective and process-reliable as possible.

[0011] This task is solved by the subject matter of the independent claims. Advantageous further developments are the subject matter of the dependent claims.

[0012] According to the invention, a liquid separation device for a compressor system comprises at least one coarse separation unit, which includes at least one coarse separator and a liquid extraction device, at least one fine separation unit, which includes at least one fine separator and a liquid extraction device, and at least one liquid extraction channel that drains liquid from the respective liquid extraction devices. The at least one liquid extraction channel is formed within the liquid separation device.

[0013] The liquid separator is used to separate a liquid from a liquid-gas flow within the compressor system. For example, a liquid separator installed downstream of an oil-lubricated compressor, such as an oil-lubricated screw compressor, can separate oil from an oil-air flow. In this case, the liquid separator is an oil separator that removes the oil from the compressed air. Alternatively, other liquids, such as those used for cooling and / or lubricating the compressor, can also be separated. Similarly, a gas other than air can be compressed by the compressor.

[0014] The liquid separator is designed as a multi-stage liquid separator, comprising at least one coarse separator unit and one fine separator unit, i.e., at least two stages. The multi-stage design of the liquid separator can, for example, increase the separation efficiency. Likewise, the multi-stage design can have a positive effect on the service life of the individual separators used, especially fine separators.

[0015] A baffle plate, for example, can be used as a coarse separator in the coarse separation unit. The liquid-gas flow introduced into the unit is initially directed onto this plate at a relatively high velocity. Other designs for coarse separators include cyclone separators or knitted screens, such as wire mesh. The liquid-gas flow, from which liquid has already been separated in the coarse separation unit, can then be transferred to the fine separation unit. The fine separation unit, for example, has a coalescing filter as its fine separator, on the outlet side of which liquid is again separated from the liquid-gas flow. However, the coarse and fine separation units do not necessarily have to differ in the type of coarse and fine separator used in a multi-stage separation process.For example, a multi-stage separation system can also have identical or at least similar separation units, where the term "coarse separation unit" refers to the fact that it contains larger quantities of liquid in the liquid-gas flow compared to the fine separation unit. The separation units are thus traversed sequentially, with the proportion of liquid in the liquid-gas flow decreasing sequentially, i.e., from the coarse separation unit to the fine separation unit.

[0016] Both the coarse separation unit and the fine separation unit each have at least one liquid extraction device, which is arranged in a drip direction relative to the respective separator for collecting the separated liquid.

[0017] To drain the liquid collected in the respective liquid extraction device, at least one liquid extraction channel is provided, extending from the device in at least one initial drainage direction. This initial drainage direction can, for example, be downwards in the direction of gravity to ensure the liquid is initially drained safely by gravity. The subsequent course of the liquid extraction channel can then deviate from this initial drainage direction. The at least one liquid extraction channel can be designed as a return channel, which returns the separated liquid to a reservoir for further use and / or processing. For example, the separated oil can be fed back into the screw block of an oil-lubricated screw compressor via this channel.

[0018] The liquid extraction channel, at least one of which is integrated into the liquid separator, ensures that the liquid is contained within the separator. Since external liquid lines are therefore unnecessary, at least in the area of ​​the separator, internal liquid routing allows for a more compact design. The liquid extraction channel is also protected from external influences by the separator. Similarly, components located within the extraction channel, such as a backflow preventer and / or nozzle (described later), can be protected from freezing, for example. Furthermore, maintenance effort is reduced, as fewer or no external lines need to be disconnected beforehand.

[0019] In addition, at least one liquid extraction channel is formed by a housing of the liquid separation device.

[0020] Accordingly, at least one liquid extraction channel can be directly integrated into the housing of the liquid separator during manufacturing. For example, the at least one liquid extraction channel can be incorporated as a casting during the manufacturing of the housing of the liquid separator. Alternatively or additionally, the at least one liquid extraction channel can be formed by means of bores.

[0021] Alternatively or additionally, it is also possible to form at least sections of the at least one liquid extraction channel in the liquid separation device by means of at least one separate liquid extraction channel line.

[0022] In In one embodiment, the at least one liquid extraction channel is designed in such a way that it has two channel sections, of which at least one channel section is fluidically connected to the liquid extraction device of the coarse separation unit and at least one other channel section is fluidically connected to the liquid extraction device of the fine separation unit.

[0023] According to such a design, the separated liquids from the coarse separation unit and the fine separation unit are combined in a liquid extraction channel via the channel sections.

[0024] Alternatively, the liquid separation device has at least two liquid extraction channels, of which at least one liquid extraction channel is fluidically connected to the liquid extraction device of the coarse separation unit and at least one other liquid extraction channel is fluidically connected to the liquid extraction device of the fine separation unit.

[0025] Accordingly, a separate liquid extraction channel is provided for the coarse separation unit and the fine separation unit.

[0026] In a particularly advantageous embodiment, at least one backflow preventer is arranged in each of the at least two channel sections or in each of the at least two liquid extraction channels. The backflow preventer is configured to prevent backflow from the at least two channel sections or the at least two liquid channels into the respective liquid extraction device connected to them.

[0027] The backflow prevention device can, for example, be designed as a check valve.

[0028] According to a further development, at least one backflow preventer is arranged in each of the at least two channel sections or in each of the at least two liquid extraction channels. The backflow preventer attributable to one of the at least two channel sections or to one of the at least two liquid extraction channels exhibits a different response behavior than the backflow preventer attributable to the other of the at least two channel sections or to the other of the at least two liquid extraction channels.

[0029] For example, different pressure conditions may prevail in the coarse separator unit and the fine separator unit. By using at least one backflow preventer in the liquid extraction channels or channel sections assigned to the liquid extraction devices of the coarse separator unit and the fine separator unit, the corresponding backflow preventer can be adapted to the prevailing pressure conditions. Alternatively, the respective backflow preventers of the coarse separator unit and the fine separator unit, such as corresponding check valves, can be identical. This reduces the number of different components to be installed and the risk of incorrect installation.

[0030] In In one embodiment, at least one nozzle is arranged in the at least one liquid extraction channel or is formed at least section by the liquid channel.

[0031] Since at least one liquid extraction channel may be used to draw off not only the separated liquid but also gas from the respective separation unit, corresponding gas losses and thus a reduction in the efficiency of the compressor system can occur. The nozzle allows the potentially gas-containing liquid or liquid-gas flow rate to be throttled, thereby reducing gas losses. This applies particularly to the liquid extraction channel or channel section leading away from the liquid extraction device of the fine separation unit, as only small quantities of liquid are separated here compared to the gas.

[0032] The nozzle can be installed as a separate component in at least one liquid extraction channel. Alternatively or additionally, the cross-section of at least one liquid channel can also be adapted, at least in sections, to implement a corresponding throttling function. This nozzle or nozzle function is thus formed directly via the at least one liquid extraction channel.

[0033] In a particularly advantageous embodiment, at least one nozzle is arranged in each of the at least two channel sections or in each of the at least two liquid extraction channels, as described above. The nozzle attributable to one of the at least two channel sections or to one of the at least two liquid extraction channels has a different cross-section than the nozzle attributable to the other of the at least two channel sections or to the other of the at least two liquid extraction channels.

[0034] Similar to the advantage of using at least one backflow preventer in the liquid extraction channels or channel sections assigned to the coarse and fine separation units, different pressure conditions in the coarse and fine separation units can be accommodated by means of correspondingly assigned nozzles. In other words, the respective nozzles can be adapted to the prevailing pressure conditions.

[0035] When using at least one backflow preventer and at least one nozzle in a liquid extraction channel or channel section, the backflow preventer is preferably arranged upstream of the nozzle in the direction of liquid drainage. In particular, the at least one backflow preventer is provided in the vicinity of the liquid extraction device to which it is assigned.

[0036] In In one embodiment, the backflow prevention device and / or the nozzle is configured to be screwed into at least one liquid extraction channel.

[0037] The backflow preventer and / or the nozzle can be easily and securely mounted in at least one liquid extraction channel. Furthermore, this allows for easy replacement, for example in the event of a failure or due to a change in characteristics.

[0038] Overall, the arrangement and design of the respective backflow preventer and / or nozzle described above enables safe and simple integration into at least one liquid extraction channel. Furthermore, the respective separation units can be reliably extracted at different pressure levels. By using the respective backflow preventer and / or nozzle for the coarse and fine separation units, for example, a bypass and thus liquid ingress from the coarse separation unit to the clean side of the fine separation unit can be prevented or at least reduced.

[0039] In one embodiment, the backflow prevention device and the nozzle for the respective separation unit are formed by a common flow control device, in particular by a common flow control element.

[0040] The flow control device can be designed as a pre-assembled unit, comprising both the backflow preventer and the nozzle as separate components. Within this pre-assembled unit, the distances between the backflow preventer and the nozzle can be preset and checked. Furthermore, individual assembly and subsequent testing can be avoided, thus reducing assembly effort. Alternatively, the flow control device can incorporate a single flow control element or be designed as such, combining the functionalities of the backflow preventer and the nozzle into a single component. In this case, the backflow preventer can be integrally integrated with the nozzle within the flow control element.

[0041] In one embodiment, the at least one liquid extraction device of the coarse separator unit and / or the at least one liquid extraction device of the fine separator unit is arranged in a liquid separation device installed below the respective associated separator, in particular in a flow-calmed area of ​​the respective separation unit.

[0042] In other words, at least one liquid extraction device of the coarse separator unit and / or at least one liquid extraction device of the fine separator unit is arranged in such a way that the liquid separated at the respective separator drips or flows directly into the respective liquid extraction device. This prevents at least the liquid separated at the respective separator from accumulating in locations from which it cannot be drained.

[0043] Furthermore, by arranging at least one liquid extraction device of the coarse separator unit and / or at least one liquid extraction device of the fine separator unit in a flow-calmed area of ​​the respective separator unit, it can be avoided that oil is carried along by the airflow.

[0044] In one embodiment, the at least one liquid extraction device of the coarse separator unit and / or the at least one liquid extraction device of the fine separator unit has a liquid outlet to the at least one liquid extraction channel, which is located at the lowest point of the at least one liquid extraction device of the coarse separator unit and / or the at least one liquid extraction device of the fine separator unit in the installation of the liquid separator unit in accordance with its intended use.

[0045] The separated liquid is thus extracted at the lowest point of at least one liquid extraction device of the respective separation unit. Consequently, riser pipes are unnecessary. This increases process reliability during maintenance, as it eliminates, for example, the risk of the riser pipe bending due to collision with another tool. Since risers are typically geometrically pointed, the absence of a riser pipe also reduces the risk of injury. Furthermore, efficiency can be increased because the prolonged period of only air being drawn in, once the oil level drops below the bottom edge of the extraction point, is avoided.

[0046] Furthermore, the separated liquid can be completely extracted, thus preventing liquid from entering other areas of the system.

[0047] In one embodiment, the at least one liquid extraction device of the coarse separation unit and / or the at least one liquid extraction device of the fine separation unit is designed as a removable cover for attachment to the housing of the liquid separation device.

[0048] Accordingly, for example, at least one liquid extraction device of the coarse separator unit and / or at least one liquid extraction device of the fine separator unit can be easily removed for maintenance purposes and to ensure accessibility of the coarse separator unit and / or fine separator unit, without having to dismantle any return lines beforehand. Since the liquid extraction channels are formed by the housing of the liquid separator unit adjacent to the respective liquid extraction device, no further bridging is required when removing the respective cover. The respective cover can, for example, be screwed, bolted, and / or otherwise detachably secured to or within the housing in a form-fitting and / or force-fit manner.The connection of the liquid outlet from the lid thus leads directly into the liquid extraction channel of the housing of the liquid separator device, so that disassembling the lid disconnects the liquid return and reconnecting the liquid return when the lid is reassembled.

[0049] To ensure that the respective liquid outlet of the respective cover is covered by the respective corresponding liquid channel, a final assembly position can be provided, for example, by screwing the cover against a stop, a corresponding drilling pattern, or markings on the cover and the housing that must be aligned.

[0050] For a fluid seal between the lid, but also generally between the liquid dispensing device or liquid outlet, and the respective liquid dispensing channel, a seal, such as an O-ring, can be arranged at the liquid outlet and / or the liquid dispensing channel facing the liquid outlet, which seals the area between the liquid outlet and the liquid dispensing channel in a fluid-tight manner. This prevents leaks.

[0051] In one embodiment, at least one liquid extraction channel is designed as a branch line or ring line.

[0052] The branch line can be easily implemented via a borehole, allowing for short distances. Alternatively, at least one liquid extraction channel can be designed as a ring main to bridge longer distances, for example. The at least one liquid extraction channel can also be composed of branch and ring main sections, and possibly other pipe sections in a different configuration.

[0053] According to a further aspect, the present invention relates to a compressor system comprising a compressor and a liquid separator device as described above. The liquid separator device is arranged outside a housing of the compressor.

[0054] The liquid separator is therefore an external liquid separator in relation to the compressor. Consequently, the liquid separator has its own external housing, into which at least one liquid extraction channel is integrated. The liquid return from the respective separation units back to the compressor or another discharge point thus occurs via the at least one liquid extraction channel inside the housing of the liquid extraction device. This at least one liquid extraction channel is formed, in particular, by the housing wall.

[0055] In one embodiment, a configuration is provided in which the compressor housing adjoins the housing of the liquid separator. In particular, at least one liquid extraction channel adjoins a suction channel of the compressor.

[0056] Consequently, the outlet of at least one liquid extraction channel can be directly connected to a corresponding inlet of the compressor, eliminating the need for additional external lines. Alternatively, due to the proximity of the liquid separator to the compressor, the distance between the separator housing and the compressor housing can be bridged with a very short return line. This can increase the compressor's compactness and reduce maintenance requirements by decreasing the number of components. Furthermore, additional protective measures for external lines can be eliminated or reduced to a minimal number.

[0057] The features described in the preceding description of the fluid separator are equally applicable to the compressor system. Likewise, features described for the compressor system are transferable to the fluid separator, provided they have not already been described therein.

[0058] According to another aspect, the present invention relates to a rail vehicle with a fluid separation device and / or a compressor system described above.

[0059] The fluid separation device or compressor system enables low-loss, cost-effective, and reliable fluid recirculation, operating reliably even under demanding conditions in rail vehicles. The increased ease of maintenance further supports the requirement for high availability of rail vehicles.

[0060] The features described above for the fluid separator and compressor system are equally applicable to the rail vehicle. Likewise, features described for the fluid separator and compressor system in relation to the rail vehicle are transferable to the rail vehicle, provided they have not already been described therein.

[0061] An exemplary embodiment of the present invention is described below with the aid of the accompanying drawing.

[0062] In detail, it shows Fig. 1 a schematic representation of an exemplary embodiment of a compressor system according to the present invention.

[0063] Fig. 1 Figure 1 shows a schematic representation of an exemplary embodiment of a compressor system 1 according to the present invention. The compressor system 1 comprises a compressor 10 with a housing 10a and a liquid separator 20 with a housing 20a. The housing 10a of the compressor is directly adjacent to the housing 20a of the liquid separator 20. In the present configuration, the compressor system 1 can also be referred to as a compressor system with a compressor and an external liquid separator. In the exemplary embodiment, the compressor 10 is an oil-lubricated screw compressor for generating compressed air. Accordingly, the liquid separator 20 is an oil separator. In alternative embodiments, the medium to be compressed can also be a gas other than air, and the liquid is not limited to oil for lubrication and / or cooling.

[0064] The liquid separation device 20 comprises a coarse separation unit 21 with a coarse separator 21a and a fine separation unit 22 with a fine separator 22a. For illustrative purposes, the coarse separator 21a is designed as a baffle plate and the fine separator 22a as a coalescing filter. In the direction of dripping of the separated liquid, here below the respective separator 21a, 22a, a liquid extraction device 21b, 22b is arranged in each of the separation units 21, 22. A liquid extraction channel 21c, 22c extends from the lowest point in the direction of dripping of the liquid extraction device 21b of the coarse separation unit 21 and the liquid extraction device 22b of the fine separation unit 22.The liquid extraction channel 21c of the coarse separator unit 21 drains separated liquid that has collected in the liquid extraction device 21b of the coarse separator unit 21, in order to return it to the compressor 10. This process is analogous for the fine separator unit 22 via the liquid extraction channel 22c of the fine separator unit 22. The collection and drainage of the separated liquid each take place in a flow-stabilized area, thus preventing the already collected liquid from being carried along by the flow in the respective separator unit 21, 22. The respective liquid extraction devices 21b and 22b are designed here as the cover of the respective separator unit 21, 22, which are detachably attached to the housing 20a. The respective connection can be disconnected for maintenance purposes.Since the respective liquid outlet of the liquid extraction devices 21b and 22b is directly adjacent to the respective liquid extraction channels 21c and 22c formed in the housing 20a, the respective separation units 21, 22 can be opened without dismantling any further bridging lines.

[0065] The liquid extraction channel 21c of the coarse separator unit 21 has a check valve 21d at its end facing the liquid extraction device 21b as a backflow prevention device. The check valve 21b prevents liquid from flowing back from the liquid extraction channel 21c into the liquid extraction device 21b. Further downstream from the liquid extraction device 21b, a nozzle 21e is also arranged in the liquid extraction channel 21c. The nozzle 21e allows the liquid or liquid-gas flow rate, which may still contain gas, to be throttled, thus reducing gas losses. The liquid extraction channel 21c is formed directly in the housing 20a of the liquid separator unit 20. This is achieved by constructing a corresponding cast part as the housing 20a.Furthermore, the design of the liquid extraction channel 21c includes threaded sections in the area of ​​the check valve 21d and the nozzle 21e, allowing the check valve 21d and the nozzle 21e to be screwed into the liquid extraction channel 21c. Further downstream of the nozzle 21e, the separated liquid is fed back directly to the compressor 10, specifically to a screw block of the screw compressor, via another section of the liquid extraction channel 21c (not shown). The return flow is routed within the housings 10a and 20a, thus eliminating the need for additional external lines.

[0066] The design of the liquid extraction channel 22c of the fine separation unit, or the arrangement of a check valve 22d as a backflow prevention device and a nozzle 22e for throttling, is analogous to the above descriptions of the liquid extraction channel 21c of the coarse separation unit 21. However, since different pressure levels prevail in the coarse separation unit 21 and in the fine separation unit 22, which result in different pressure conditions when the separated liquid is extracted from the respective liquid extraction devices 21b, 22b via the respective liquid extraction channels 21c, 22c, the respective check valves 21d, 22d and nozzles 21e, 22e differ from one another. In other words, the check valve 21d and the nozzle 21e, which are assigned to the coarse separator unit 21, are adapted to the prevailing pressure level in the coarse separator unit 21 and the resulting pressure ratio.Conversely, the check valve 22d and the nozzle 22e, which are assigned to the fine separation unit 22, are adapted to the prevailing pressure level in the fine separation unit 22 and the resulting pressure ratio.

[0067] During the operation of compressor system 1, the compressed oil-air volume flow is referred to here, in relation to the oil-lubricated screw compressor as compressor 10, in Fig. 1As indicated by the black arrows, the compressed oil-air flow is introduced into the coarse separator unit 21. There, it encounters the baffle plate acting as the coarse separator 21a, causing an initial portion of the oil to be separated from the oil-air flow at the coarse separator 21a and drip into the liquid extraction device 21b below. The oil collected in the liquid extraction device 21b of the coarse separator unit 21 is drawn off through the liquid extraction channel 21c of the coarse separator unit 21 via the check valve 21d and the nozzle 21e located in the liquid extraction channel 21c, and is then returned to the screw block of the compressor 10.

[0068] The compressed oil-air flow, from which some of the oil has already been separated in the coarse separator unit 21, then flows from the coarse separator unit 21 into the fine separator unit 22. In the fine separator unit 22, the compressed oil-air flow passes through the fine separator 22a, thereby separating more oil, which is then collected in the liquid extraction device 22b of the fine separator unit 22. Analogous to the extraction of the oil from the coarse separator unit 21, the separated oil is also extracted and returned in the fine separator unit 22 through the liquid extraction channel 22c of the fine separator unit 22, via the check valve 22d and the nozzle 22e located in the liquid extraction channel 22c, into the screw block of the compressor 10.

[0069] In the exemplary embodiment, the liquid extraction channel 22c of the fine separation unit 22 and the liquid extraction channel 21c of the coarse separation unit 21 are combined within the housing 20a of the liquid separation device 20 to form a common liquid extraction channel (not shown) in order to supply the extracted oil to the screw block of the compressor 10 via this common liquid extraction channel. In alternative embodiments, however, the liquid extraction channel 22c of the fine separation unit 22 and the liquid extraction channel 21c of the coarse separation unit 21 can also be routed separately within the housing 20a of the liquid separation device 20, either to open into a common liquid extraction channel in the housing 10a of the compressor or to each lead to a separate inlet in the screw block of the compressor 10.

[0070] The invention is not limited to the described embodiment. In particular, features described in relation to this embodiment, other described embodiments and further developments of the invention can be combined with one another, provided they are not mutually exclusive. REFERENCE MARK LIST

[0071] 1 Compressor system 10 Compressor 10a Housing (Compressor) 20 Liquid separator 20a Housing (Liquid separator) 21 Coarse separator unit 21a Coarse separator 21b Liquid extraction device (Coarse separator unit) 21c Liquid extraction channel (Coarse separator unit) 21d Check valve (Coarse separator unit; backflow prevention device) 21e Nozzle (Coarse separator unit) 22 Fine separator unit 22a Fine separator 22b Liquid extraction device (Fine separator unit) 22c Liquid extraction channel (Fine separator unit) 22d Check valve (Fine separator unit; backflow prevention device) 22e Nozzle (Fine separation unit)

Claims

1. Liquid separation device (20) for a compressor system (1), comprising: at least one coarse separation unit (21) comprising at least one coarse separator (21a) and a liquid removal device (21b), at least one fine separation unit (22) comprising at least one fine separator (22a) and a liquid removal device (22b), and at least one liquid removal channel (21c, 22c) which discharges a liquid from the respective liquid removal devices (21b, 22b), characterized in that the at least one liquid removal channel (21c, 22c) is formed in the liquid separation device (20), wherein the at least one liquid removal channel (21c, 22c) is formed by a housing (20a) of the liquid separation device (20).

2. Liquid separation device (20) according to claim 1, wherein the at least one liquid removal channel (21c, 22c) comprises at least two channel portions, of which the at least one channel portion is fluidically connected to the liquid removal device (21b) of the coarse separation unit (21) and the at least one other channel portion is fluidically connected to the liquid removal device (22b) of the fine separation unit (22), or the liquid separation device (20) comprises at least two liquid removal channels (21c, 22c), of which the at least one liquid removal channel (21c) is fluidically connected to the liquid removal device (21b) of the coarse separation unit (21) and the at least one other liquid removal channel (22c) is fluidically connected to the liquid removal device (22b) of the fine separation unit (22).

3. Liquid separation device (20) according to claim 2, wherein at least one backflow prevention device (21d, 22d) is arranged in each of the at least two channel portions or in each of the at least two liquid removal channels (21c, 22c), and wherein the backflow prevention device (21d, 22d) is configured to prevent a backflow from the at least two channel portions or the at least two liquid removal channels (21c, 22c) into the respective liquid removal device (21b, 22b) connected thereto.

4. Liquid separation device (20) according to claim 3, wherein the at least one backflow prevention device (21d, 22d) is arranged in each of the at least two channel portions or in each of the at least two liquid removal channels (21c, 22c), and wherein the backflow prevention device (21d, 22d) assignable to the one of the at least two channel portions or the one of the at least two liquid removal channels (21c, 22c) has a different response behavior than the backflow prevention device (21d, 22d) assignable to the other of the at least two channel portions or the other of the at least two liquid removal channels (21c, 22c).

5. Liquid separation device (20) according to any one of the preceding claims, wherein at least one nozzle (21e, 22e) is arranged in the at least one liquid removal channel (21c, 22c) or is formed at least sectionally by the liquid channel (21c, 22c).

6. Liquid separation device (20) according to claim 5, wherein the at least one nozzle (21e, 22e) is arranged in each of the at least two channel portions or in each of the at least two liquid removal channels (21c, 22c) according to claim 3, and wherein the nozzle (21e, 22e) assignable to the one of the at least two channel portions or the one of the at least two liquid removal channels (21c, 22c) has a different cross section than the nozzle (21e, 22e) assignable to the other of the at least two channel portions or the other of the at least two liquid removal channels (21c, 22c).

7. Liquid separation device (20) according to any one of claims 3 to 6, wherein the backflow prevention device (21d, 22d) and / or the nozzle (21e, 22e) are / is screwable into the at least one liquid removal channel (21c, 22c).

8. Liquid separation device (20) according to any one of claims 3 to 7, wherein the backflow prevention device (21d, 22d) according to any one of claims 3, 4 or 7 and the nozzle (21e, 22e) are formed by a common flow control device, in particular by a common flow control member.

9. Liquid separation device (20) according to any one of the preceding claims, wherein the at least one liquid removal device (21b) of the coarse separation unit (21) and / or the at least one liquid removal device (22b) of the fine separation unit (22) are / is arranged below the respective associated separator (21a, 22a), in particular in a flow-calmed region of the respective separation unit (21, 22), in an installation of the liquid separation device (20) suitable for use.

10. Liquid separation device (20) according to any one of the preceding claims, wherein the at least one liquid removal device (21b) of the coarse separation unit (21) and / or the at least one liquid removal device (22b) of the fine separation unit (22) comprise / s a liquid outlet to the at least one liquid removal channel (21c, 22c), which is located at a lowest point of the at least one liquid removal device (21b) of the coarse separation unit (21) and / or the at least one liquid removal device (22b) of the fine separation unit (22) in an installation of the liquid separation device (20) suitable for use.

11. Liquid separation device (20) according to any one of the preceding claims, wherein the at least one liquid removal device (21b) of the coarse separation unit (21) and / or the at least one liquid removal device (22b) of the fine separation unit (22) are / is formed as a detachable cover for fastening to the housing (20a) of the liquid separation device (20).

12. Liquid separation device (20) according to any one of the preceding claims, wherein the at least one liquid removal channel (21c, 22c) is formed as a stub line or ring line.

13. Compressor system (1), comprising: a compressor (10) and a liquid separation device (20) according to any one of claims 1 to 12, wherein the liquid separation device (20) is arranged outside a housing (10a) of the compressor (10).

14. Compressor system (1) according to claim 13, wherein the housing (10a) of the compressor (10) adjoins the housing (20a) of the liquid separation device (20), in particular the at least one liquid removal channel (21c, 22c) adjoins a suction channel of the compressor (10).

15. Rail vehicle having a fluid separation device (20) according to any one of claims 1 to 12 and / or a compressor system (1) according to claim 13 or 14.