Coalescence Separator, in Particular for Use in a Compressed Air Compressor System, Compressed Air Compressor System, and Use of a Coalescence Separator

Abstract

A coalescence separator for separating liquid droplets from a gas flow is provided with a multilayer structure of a coalescence filter medium as a finest stage of the coalescence separator. The multilayer structure of the coalescence filter medium is arranged between a gas inlet and a gas outlet and surrounds a cavity. A product of an air permeability of the coalescence filter medium and a grammage of the coalescence filter medium amounts to at least 16 g/m*s and maximally 100 g/m*s. The coalescence filter medium is a glass fiber paper. The coalescence separator is used, for example, as a main oil separator in screw compressors.

Claims

1. A coalescence separator for separating liquid droplets from a gas flow, the coalescence separator comprising: a multilayer structure comprised of a coalescence filter medium as a finest stage of the coalescence separator; wherein the multilayer structure comprised of the coalescence filter medium is configured to be arranged between a gas inlet and a gas outlet and surrounds a cavity; wherein a product of an air permeability of the coalescence filter medium and a grammage of the coalescence filter medium amounts to at least 16 g/m*s and maximally 100 g/m*s.

2. The coalescence separator according to claim 1, wherein the coalescence filter medium is a glass fiber paper.

3. The coalescence separator according to claim 1, further comprising two end discs, wherein the multilayer structure is fastened seal-tightly between the two end discs for lateral sealing.

4. The coalescence separator according to claim 1, wherein an individual layer thickness of the coalescence filter medium amounts to more than 0.1 mm and maximally 2 mm.

5. The coalescence separator according to claim 1, wherein an individual layer of the coalescence filter medium comprises a grammage larger than 40 g/m.sup.2 and less than 200 g/m.sup.2.

6. The coalescence separator according to claim 1, wherein the coalescence filter medium comprises a mass to volume ratio of less than 170 kg/m.sup.3 and larger than 80 kg/m.sup.3.

7. The coalescence separator according to claim 1, wherein an individual layer of the coalescence filter medium has an air permeability of more than 180 l/m.sup.2s and maximally 1,500 l/m.sup.2s.

8. The coalescence separator according to claim 1, wherein the multilayer structure comprises between 2 and 80 layers of the coalescence filter medium.

9. The coalescence separator according to claim 8, wherein the layers of the coalescence filter medium are immediately arranged on each other and are either stacked or wound.

10. The coalescence separator according to claim 1, wherein the coalescence filter medium is a single layer.

11. The coalescence separator according to claim 10, wherein the single layer is preferably homogenous.

12. The coalescence separator according to claim 1, wherein a total thickness of the multilayer structure amounts to at least 8 mm and maximally 60 mm.

13. The coalescence separator according to claim 1, wherein a total air permeability of the multilayer structure amounts to less than 100 l/m.sup.2s.

14. The coalescence separator according to claim 1, wherein the coalescence filter medium comprises glass fibers in a mass proportion of at least 50%.

15. The coalescence separator according to claim 1, wherein the coalescence filter medium comprises incinerable materials in a mass proportion of maximally 10%.

16. The coalescence separator according to claim 1, wherein the coalescence filter medium comprises a binder in a mass proportion of maximally 10%.

17. The coalescence separator according to claim 16, wherein the binder comprises no fibers selected from the group consisting of bi-component fibers and fusible fibers.

18. The coalescence separator according to claim 16, wherein the binder is an acrylate binder.

19. The coalescence separator according to claim 1, wherein the coalescence filter medium comprises fibers comprising hydrophobic properties; fibers comprising oleophobic properties; or fibers comprising hydrophobic properties and oleophobic properties.

20. The coalescence separator according to claim 1, wherein the coalescence filter medium comprises glass fibers, wherein at least 90% of the glass fibers have a fiber diameter larger than 0.5 m.

21. The coalescence separator according to claim 1, wherein the coalescence filter medium comprises glass fibers, wherein at least 90% of the glass fibers have a fiber diameter of less than 10 m.

22. The coalescence separator according to claim 1, wherein a finest separation stage of the coalescence separator is formed by the multilayer structure and/or the coalescence filter medium.

23. The coalescence separator according to claim 1, wherein the multilayer structure and/or the coalescence filter medium forms a separation stage determining at least mostly an efficiency of the coalescence separator.

24. The coalescence separator according to claim 1, configured as a first separation stage comprised of fibers and configured to be arranged downstream of a screw of a screw compressor.

25. The coalescence separator according to claim 24, wherein the fibers are glass fibers.

26. The coalescence separator according to claim 1, configured as an exchangeable coalescence separator insert for exchangeable installation in a pressure container of a compressed air compressor.

27. The coalescence separator according to claim 1, configured as a main oil separator of a screw compressor, the coalescence separator further comprising a fine coalescing separator arranged downstream of the multilayer structure for post separation of residual oil in a compressed air flow of the screw compressor.

28. A compressed air compressor system, comprising a pressure container for stationary compressors or comprising a separator cartridge housing, embodied as a spin-on filter and mountable on a connecting head, the compressed air compressor system further comprising a coalescence separator according to claim 1, wherein the coalescence separator is arranged exchangeably in the pressure container or is arranged exchangeably in the separator cartridge housing so as to be exchangeable together with the separator cartridge housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] As has already been explained above, there are various possibilities to embody and further develop the teachings of the present invention in an advantageous manner. In this context, on the one hand, reference is being had to the dependent claims; on the other hand, further embodiments, features, and advantages of the present invention will be explained in more detail in the following inter alia with the embodiments illustrated in FIGS. 1 to 4 as well as further examples.

[0032] FIG. 1 shows a schematic perspective partial section view of an embodiment of a fluid separator.

[0033] FIG. 2 shows a second schematic perspective partial section view of the fluid separator arrangement according to FIG. 1.

[0034] FIG. 3 shows a schematic plan view of an exchangeable coalescence separator insert which is usable in a fluid separator according to FIG. 1.

[0035] FIG. 4 shows a schematic section view of the exchangeable coalescence separator insert according to FIG. 3.

[0036] In the Figures, same or functionally the same elements, if nothing to the contrary is mentioned, are provided with the same reference characters.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0037] FIG. 1 shows a schematic perspective partial section view of an embodiment of an oil separator or fluid separator 1. The fluid separator 1 works according to the coalescing separator principle in which liquid droplets from a gas flow deposit on the fibers of a fibrous coalescence filter medium, combine (coalesce) thereat to larger droplets, and drain off due to gravity. The fluid separator 1 is designed to separate a liquid fluid, for example, oil, from a gaseous fluid, for example, compressed air. The fluid separator 1 can be associated with a screw compressor or a screw compressing device or can be part of a screw compressor or screw compressing device.

[0038] The fluid separator 1 comprises a compressed air vessel 2 with a tubular wall 3 which may be circular in cross section. At the wall 3, a fluid inlet 4 can be provided. The fluid inlet 4 can be tubular with a circular cross section. The fluid inlet 4 penetrates the wall 3. By means of the fluid inlet 4, a fluid F1, for example, an oil/ air mixture, can be supplied radially but also tangentially to the fluid separator 1. The fluid F1 can be supplied to the fluid separator 1 from the aforementioned screw-type compressing device.

[0039] At the end face, the compressed air vessel 2 is closed off by means of a curved, in particular spherically curved, bottom 5. The bottom 5 and the wall 3 can be designed monolithically. Centrally at the bottom 5, a fluid outlet 6 can be provided. By means of the fluid outlet 6, a fluid F2, for example, oil that has been separated from the fluid F1 can be discharged or removed by suction. At an end section of the wall 3 facing away from the bottom 5, the compressed air vessel 2 comprises moreover a connecting flange 7 that is embodied annularly.

[0040] The fluid separator 1 comprises moreover a cover 8 that is detachably connected to the connecting flange 7 of the compressed air vessel 2. For example, the cover 8 is connected by means of screws to the connecting flange 7. For this purpose, for example, corresponding bores 9 can be provided at the cover 8 and threaded bores 10 corresponding with the bores 9 can be provided at the connecting flange 7.

[0041] A tubular fluid outlet 11 is provided centrally at the cover 8. By means of the fluid outlet 11, a fluid F3, for example, purified compressed air, from which the fluid F2 has been separated, can be discharged. For example, the fluid F3 can be supplied to a compressed air system and consumers connected thereto. In a direction of the force of gravity g, the fluid outlet 11 is preferably arranged above the fluid inlet 4 and the fluid outlet 6.

[0042] The fluid separator 1 comprises moreover a coalescence separating arrangement 12, in particular an oil separator arrangement that is embodied as a coalescence separator. The coalescence separator arrangement 12 comprises, for example, as provided in the present embodiment, a cup-shaped filter housing 13 which forms an intermediate housing within the compressed air vessel 2 as well as a plurality of exchangeable coalescence separator inserts 14 received in the filter housing 13. The exchangeable coalescence separator inserts 14 can also be referred to as coalescence separator elements, coalescing elements, separator elements in particular oil separator elements, or filter elements. The number of exchangeable coalescence separator inserts 14 is arbitrary. For example, as shown in FIG. 1, four such exchangeable coalescence separator inserts 14 can be provided. Alternatively, for example, also two, three, four, five or more exchangeable coalescence separator inserts 14 but also only one such exchangeable coalescence separator insert 14 can be provided.

[0043] The filter housing 13 comprises a tubular wall 15 which in cross section may have a circular geometry. At one end section of the wall 15 a connecting flange 16 is provided which is arranged between the cover 8 and the connecting flange 7 of the compressed air vessel 2. This means that the connecting flange 16 can be clamped between the cover 8 and the connecting flange 7 of the compressed air vessel 2. In the connecting flange 16, bores 17 can be provided which correspond to the bores 9 of the cover 8 and the threaded bores 10 of the connecting flange 7.

[0044] FIG. 2 shows a schematic perspective partial section view of the coalescence separator arrangement 12. At an end section of the wall 15 which is facing away from the connecting flange 16, a filter element adapter plate 18 is provided at which the exchangeable coalescence separator insert 14 is fastened. The filter element adapter plate 18 can be connected non-detachably or detachably, i.e., exchangeably, to the filter housing 13. For example, the filter element adapter plate 18 is screwed into the tubular wall 15 or connected thereto, for example, by means of a bayonet closure. The filter element adapter plate 18 is connected fluid-tightly with the wall 15. This means that no fluid can escape between the filter element adapter plate 18 and the wall 15. The arrangement with a plurality of exchangeable coalescence separator inserts 14 is exemplary for the present invention. Instead of an adapter plate 18 with a plurality of exchangeable coalescence separator inserts 14, a single exchangeable coalescence separator insert can also be used with the size and with the flange configuration of the adapter plate 18, as is conventional also in the prior art.

[0045] FIG. 3 shows a schematic view of the exchangeable coalescence separator insert 14 and FIG. 4 shows a schematic section view of the exchangeable coalescence separator insert 14. In the following, reference is being had to FIG. 3 and FIG. 4 at the same time.

[0046] The exchangeable coalescence separator insert 14 can be designed with rotational symmetry relative to the center axis or symmetry axis M. The exchangeable coalescence separator insert 14 comprises a first end disc 19, which is shown in FIGS. 3 and 4 in different views, and a second end disc 20. The first end disc 19 and the second end disc 20 can be manufactured, for example, of a metal material, in particular steel, or of a plastic material. Preferably, the end discs 19, 20 are manufactured of a sheet metal, in particular sheet steel, respectively.

[0047] Between the first end disc 19 and the second end disc 20, a coalescence filter medium 21 of a wound multilayer structure is arranged. A construction, in which a plurality of layers of the coalescence filter medium are placed directly, without a spacing, onto each other, preferably wound, so that a fibrous body which is substantially uniform transverse to the layer extension is created, is referred to as a multilayer structure. In this context, the coalescence filter medium 21 is preferably not folded but flat. Preferably, the coalescence filter medium 21 can be in particular a wound glass fiber nonwoven or glass fiber paper. The glass fibers are preferably micro glass fibers. The first end disc 19 and the second end disc 20 can be glued to the coalescence filter medium 21 or connected in other ways. The exchangeable coalescence separator insert 14 can comprise, for example, a height h14 of approximately 500 mm and a diameter d14 of approximately 150 mm. The second end disc 20 comprises preferably, as illustrated, a handle 22 for handling the exchangeable coalescence separator insert 14. The multilayer structure of the coalescence filter medium 21 is surrounded at the clean side by a drainage nonwoven 210 that is of an open-pore structure in comparison to the coalescence filter medium and is preferably arranged without spacing or without intermediate space relative to the multilayer structure and surrounds the latter completely. The drainage nonwoven contributes to draining off the separated liquid without the already separated liquid being entrained by the flow and can catch such entrained droplets. In an intended flow direction from the exterior to the interior, which is also possible according to the invention, the drainage nonwoven 210 is arranged within the multilayer structure of the coalescence filter medium 21.

[0048] As illustrated in FIG. 4, the exchangeable coalescence separator insert 14 has a raw side RO and a clean side RL which is separated from the raw side RO by means of the coalescence filter medium 21. The fluid F1 to be filtered flows in this context from the raw side RO through the coalescence filter medium 21 to the clean side RL wherein, by means of the coalescence filter medium 21, the fluid F2, in particular oil, can be separated from the fluid F1, in particular (compressed) air/oil mixture, and drained off so that the purified fluid F3, in particular purified (compressed) air, passing through the coalescence filter medium 21, exits at the clean side RL. The fluid F2 is separated in the coalescence filter medium 21 in small droplets which deposit on the fibers. The small droplets coalesce to larger drops that, in turn, flow along and within the coalescence filter medium 21 as well as along and within the drainage nonwoven 210 in the direction of the force of gravity g in downward direction. The separated fluid F2 therefore does not remain within the coalescence filter medium 21 but drains in downward direction and collects, for example, at the filter element adapter plate 18 of the filter housing 13, wherein the fluid F2 can be sucked away by a drainage line 212. The first end disc 19 comprises a fluid inflow opening 23 (a flow in the opposite direction is possible) that can be embodied with rotational symmetry to the symmetry axis M. Via the fluid inflow opening 23, the fluid F1 can enter the interior 24 of the exchangeable coalescence separator insert 14. Moreover, the fluid F2 can exit through the fluid inflow opening 23 from the exchangeable coalescence separator insert 14 but also via the outer rim of the lower first end disc 19. The first end disc 19 comprises moreover preferably at least three fastening elements 25 to 27, which are non-uniformly distributed about the fluid inflow opening 23, for fastening at the filter element adapter plate 18. The number of fastening elements 25 to 27 is arbitrary. Preferably, however, at least three such fastening elements 25 to 27 are provided. However, also four, five or more such fastening elements 25 to 27 can be provided.

[0049] The first or open end disc 19 can comprise moreover a sealing element 28, for example, an O-ring, in order to seal the first end disc 19 fluid-tightly relative to the filter element adapter plate 18 or a flange of the compressed air vessel 2. The fastening elements 25 to 27 are embodied to engage from behind the filter element adapter plate 18 by form fit. A form fit connection is produced by the meshing engagement or engagement from behind of at least two connecting partners, in this case the fastening elements 25 to 27 and the filter element adapter plate 18.

[0050] The fastening elements 25 to 27 can be arranged along a circle in non-uniform or non-symmetrical distribution about the fluid inflow opening 23.

EXAMPLES

[0051] Embodiments of a coalescence separator according to the invention were compared to a combined two-stage structure. In this context, for same outer dimensions different coalescence filter media were used. Degrees of separation were determined based on an aerosol with a volume-weighted average droplet size of approximately 1.1 m. In this context, it becomes apparent that in the comparative example for same dimensions a significantly higher pressure loss must be accepted for fulfilling the market requirements.

TABLE-US-00001 TABLE 1 product air thick- grammage* coalescence perme- ness air perme- filter grammage ability mm @ ability medium g/m.sup.2 l/m.sup.2s 10 kPa g/(m*s) Examples Example 1 glass fiber 95 195 0.8 19 paper with appr. 95% glass fibers Example 2 glass fiber 70 230 0.53 16 paper with appr. 95% glass fibers Comparative examples Comparative glass fiber 70/89 230/130 0.5/0.59 16/10 example 1 paper with appr. 95% glass fibers, two-stage structure (stage 1/ stage 2) proportion of degree of pressure fibers smaller separation difference than 3 m layers % mbar Examples Example 1 <10% 15 fulfills market 80 requirements Example 2 <10% 20 fulfills market 92 requirements Comparative examples Comparative <10% 5/10 fulfills market 127 example 1 requirements
In the examples 1 and 2 in Table 1, the described multilayer structures were used as the only main separation stage, i.e., the coalescence separators had no finer separation stage. In comparative example 1, a comparatively open layer was combined with a comparatively fine layer in a so-called two-stage structure. All structures were adjusted such that they fulfill a degree of separation that fulfills market requirements and then compared with regard to pressure loss. Surprisingly, in examples 1 and 2, without employing a fine stage as in the comparative example with a reduced air permeability (in the comparative example 130 l/m.sup.2s), the requirements in regard to degree of separation were fulfilled and improvements in regard to pressure loss were obtained while having acceptable stack dimensions.