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(11) | EP 1 382 927 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Cooling device |
| (57) Cooling device (1) comprising at least one gas or air cooling chamber (3) and at
least one fluid cooling chamber (2), particularly oil cooling chamber, positioned
adjacently, as well as one or more tubes (7) for passage of coolant, which tubes (7)
extend through both the air cooling chamber (3) and the fluid cooling chamber (2),
in which between the adjacently placed walls of the air cooling chamber and the fluid
cooling chamber, a separation chamber (26,27) is placed through which the tubes (7)
extend, in which in the separation chamber means (24) are placed which are in stationary
contact with the outer surface of the tubes (7) for intercepting a fluid flow past
said outer surface. |
[0001] The invention relates to a combined cooling device having one or more gas/air cooling chambers and one or more fluid/oil cooling chambers. The invention furthermore relates to a compressor such as a screw-type compressor, piston compressor, turbo compressor and the like, provided with such a cooling device.
[0002] Such cooling devices, wherein the medium to be cooled is passed through both cooling chambers in tubes, are among other things used in oil-free screw-type compressors, such as for the food industry.
[0003] Combined coolers have the advantage of being compact, being simple to assemble, having a reduced weight, having a reduced cost price, etc.
[0004] It may be of importance here to prevent oil from an oil chamber to end up in a next air cooling chamber, due to overpressure in the oil cooling chamber or underpressure in the air cooling chamber, as a result of which an oil leakage flow can take place past the tubes clamped in the tube plate, as far as into the air cooling chamber.
[0005] In case of an adjacently placed air cooling chamber and oil chamber, it was suggested before to space apart the pipes/tube plates that limit these chambers in order to form a separation chamber. Said separation chamber was provided with a leakage discharge for oil that had leaked from the oil chamber past the tubes clamped in the tube plate. In case a relatively large underpressure occurred in the air cooling chamber, it could however happen that oil that had leaked past the pipes, was as it were sucked in by the air cooling chamber, or after having arrived at the tube plate of the air cooling chamber could access the air cooling chamber as a result of capillary action.
[0006] It is an object of the invention to provide a cooling device of the type mentioned in the preamble with which this problem is prevented.
[0007] To that end the invention provides a cooling device comprising at least one gas or air cooling chamber and at least one fluid cooling chamber, particularly oil cooling chamber, positioned adjacently, as well as one or more tubes for passage of coolant, which tubes extend through both the air cooling chamber and the fluid cooling chamber, in which between the adjacently placed walls of the air cooling chamber and the fluid cooling chamber, a separation chamber is placed through which the tubes extend, in which in the separation chamber means are provided that engage on the outer surface of the tubes for intercepting a fluid flow past said outer surface.
[0008] As a result the oil that has sweated from the oil cooling chamber past the pipes is prevented from being sucked in by the air cooling chamber.
[0009] Preferably the interception means form physical means that have been placed in stationary connection or contact with the outer surface of the tubes. Preferably the interception means comprise an intermediate plate, through which the tubes extend. The leaking oil then comes into contact with the intermediate plate and is thus deflected. Preferably the tubes are attached in the intermediate plate by rolling.
[0010] The separation chamber is preferably provided with a discharge for leakage fluid, so that the leakage can be determined, which is of importance for testing the cooling device.
[0011] Preferably the intermediate plate divides the separation chamber into two sub-chambers, means being provided for keeping both sub-chambers at the same pressure. Because at both sides of the intermediate plate the same pressure prevails, no force oriented in tube direction is exerted on the oil leaking past the tubes, as a result of which the leakage flow is stopped.
[0012] In a possible embodiment thereof, the means for keeping both sub-chambers at the same pressure comprise passages from each sub-chamber to the surrounding area, the pressure in the sub-chambers then being kept at the ambient pressure.
[0013] In an alternative embodiment the means for keeping both sub-chambers at the same pressure comprise passages from the one sub-chamber to the other, such as through the intermediate plate.
[0015] The interception and discharge of the leaking oil is improved when the tubes extend substantially horizontally.
[0016] From a further aspect the invention provides a cooling device comprising at least one gas or air cooling chamber and at least one fluid cooling chamber, particularly oil cooling chamber, positioned adjacently, as well as one or more tubes for passage of coolant, which tubes extend through both the air cooling chamber and the fluid cooling chamber, which air cooling chamber and fluid cooling chamber at least at the sides facing each other are limited by tube plates, a separation chamber being formed between both tube plates, in which separation chamber an intermediate plate has been placed which is positioned at a distance from both tube plates, the tubes extending through the tube plates and the intermediate plate.
[0017] Preferably the spaces between the intermediate plate and the tube plates are at the same pressure.
[0018] Preferably both spaces are provided with a discharge for leakage fluid from the fluid cooling chamber. Pressure equalizing may optionally also take place via the discharge.
[0020] In case of tube plates having a separation chamber positioned in between them it was common to attach the tube plates at the end flanges of the circumferential walls of the air cooling chamber and the oil cooling chamber. The tubes themselves were clamped in the tube passages in the tube plates in the usual manner by rolling. In case the tubes expanded or shrunk, large pressure stress and tensile stress occurred in the tubes, resulting in a deteriorated sealing and as a result leakage and possibly damage or collapsing of the tubes.
[0021] From a further aspect of the invention a solution is provided for this problem by means of a cooling device comprising at least one gas or air cooling chamber and at least one fluid cooling chamber, particularly oil cooling chamber, positioned adjacently, as well as one or more tubes for passage of coolant, which tubes extend through both the air cooling chamber and the fluid cooling chamber, as well as a housing having circumferential walls surrounding the air cooling chamber and the fluid cooling chamber, which air cooling chamber and fluid cooling chamber at least at the sides facing each other are limited by tube plates, a separation chamber being formed between both tube plates, the tube plates extending in outward direction at least almost to the profile defined by the circumferential walls. The tube plates can now move along with the tubes, as a result of which the normal stress (tensile and pressure) in the tubes cannot become too high. It is now possible to place the oil cooling chamber, which before always had to be fixedly positioned at the location of the distribution chamber for the cooling water, at any given location in the cooling device.
[0022] Preferably the tube plates abut the inner surface of the circumferential walls via sealing rings.
[0023] In an assembly friendly embodiment the tube plates and the intermediate plate form one mountable unity. This unity may advantageously be slidable in axial direction in and out of the cooling device. The placement is tolerance insensitive so that afterwards a bundle can easily be replaced.
[0024] It is preferred then that the cooling device at one end is provided with a reversing or distribution chamber for cooling water and with a further tube plate for limitation of the distribution chamber to an adjacent cooling chamber, the further tube plate forming a slidable unity with the said intermediate plate and the tube plates, as well as with the ordinary intermediate plates between the air cooling chambers. Thus a complete assembly of separation chamber, a tube plate situated at an end of the cooling device and cooling lamellas attached to the tubes can be slid in an out of the cooling device as one unity.
[0025] Preferably an intermediate plate is placed in the separation chamber which intermediate plate is positioned at a distance from both tube plates, the tubes extending through the tube plates and the intermediate plate and being clamped in them. The spaces between the intermediate plate and the tube plates advantageously are at the same pressure and are both provided with a discharge for leakage fluid from the fluid cooling chamber.
[0026] The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawing in which:
Figure 1 shows a vertical cross-section of a part of a cooling device according to the invention; and
Figure 1A shows a detail of the cooling device according to figure 1.
[0027] Figure 1 shows a combined cooling device 1 for for instance an oil-free compressor. The cooling device 1 in the example comprises an oil cooling chamber 2 and an air cooling chamber 3, provided with circumferential walls 8 and 9, respectively. At the head the oil cooling chamber 2 is closed off by a tube plate 6, which forms the limitation of a cooling water space 5 for reversing the cooling water, limited by a cover plate 4. In the cover plate 4 drain passages 32 have been provided. From the cooling water space 5 tubes 7 extend through the tube plate 6, in figure 1 in substantially horizontal direction, through the oil cooling chamber 2 and subsequently through the air cooling chamber 3. At the left end the cooling device is limited by a distribution chamber and connections for the cooling water (not shown).
[0028] The oil cooling chamber 2 defines an inner space 10, in which cooling lamellas 30 have been arranged, which are in cooling contact with the tubes 7, only one of which is shown. In the same manner the air cooling chamber 3 has been provided with a space 11, in which cooling lamellas 31 have been placed that are also in cooling contact with the tubes 7. The cooling lamellas are clamped on the tubes in the usual manner by means of a mandrel through expansion.
[0029] The oil cooling chamber has a supply 12 for supplying oil in the direction B, and a discharge 13 for discharge of oil in the direction C. The air cooling chamber 3 has a supply 14 for air in the direction D, and a discharge 15 for discharge of air in the direction E.
[0030] The circumferential walls 8 and 9 of the oil cooling chamber 2 and the air cooling chamber 3 end at a distance from each other, a closing ring 23 being placed between both circumferential walls 8 and 9, which closing ring is substantially U-shaped. The legs of the U-shaped closing ring 23 have been turned with end edges 23a, which fit in chambers 19 and 20 that have been formed in the end edges of the circumferential walls 8 and 9. The turned edges 23a then abut 0-rings or sealing rings 21, 22.
[0031] Radially within the turned edges 23a and sealing rings 21, 22 an assembly 16 has been fittingly placed, which assembly comprises a first tube plate 17 and a second tube plate 18, which seal the oil cooling chamber 2 and the air cooling chamber 3, respectively, and pass the tubes 7. The tube plates 17 and 18 have an outer diameter which is slightly smaller than the inner diameter D1 of the circumferential walls 8 and 9. As a result the assembly 16 is snugly accommodated in the circumferential walls 8 and 9. The same goes for the tube plate 6.
[0032] Both tube plates 17 and 18 are spaced apart, and in between them accommodate a tube plate 24, which with the tube plates 17 and 18 and their turned edges 17a and 18a, defines chambers 26 and 27, respectively.
[0033] The closing ring 23 defines an annular chamber 25 with the turned edges 17a and 18a, which annular chamber 25 at the lower side of the cooling device 1 has been provided with a discharge opening 28 which can be controlled with discharge nipple 29. The discharge nipple 29 can be opened so that the ambient pressure prevails in both chambers 26 and 27.
[0034] The tube plates 17 and 18 are attached to the tubes 7 in the usual manner. By means of rolling the wall of tube 7 is expanded to bring the wall material of the tube 7 in close contact with the boundary of the passage in the tube plates 17 and 18. As a result the tube plates 17 and 18 form one unity with the tubes 7. When the tubes 7 extend or shorten due to influences of temperature, the tube plates 17 and 18 are able to move along in their entirety in the directions I, within the circumferential walls 8 and 9. Unwanted stress is thus prevented. Also the tube plate 6 forms one unity with the tubes 7 and thus with the tube plates 17 and 18, and via an 0-ring 40 abuts the inner surface of the circumferential wall 8. After removal of the cover plate 4 the whole of tube plates 6, 17 and 18 with tubes 7 and cooling lamellas 30 can be slid out of the cooling chamber.
[0035] When during use oil leaks past the outer surface of a tube 7 in the direction F, through the clamping opening in the tube plate 17, the oil will at some moment or other end up at the location where the tube 7 extends in the intermediate plate 24, and be deflected by said intermediate plate 24 in the direction G, corresponding to the direction of gravity. The oil can then enter into the space 25 through opening 34 in the turned edge 17a of the tube plate 17, and be drained via the leakage opening 28 and discharge nipple 29.
[0036] Due to the openings 34 and 35 in the edges 17a and 18a both chambers 26 and 27 are at ambient pressure, so that there is no pressure difference over the intermediate plate 24. Alternatively a pressure difference over the plate 24 can be counteracted by arranging one or more holes 50 in said plate, which holes connect the chambers 26 and 27 with each other, where room is present in the plate 24, particularly adjacent to the area where the tubes 7 are absent.
[0037] The arrangement according to the invention is also advantageous in the so-called compression with water, in which the oil cooling chamber is put under high pressure to test the oiltightness of the cooling device. Use is made of the discharge opening in connection with the air cooling chamber 3 for simple reception of leakage water. When after a certain amount of time no drops of water have been seen coming out of the detection opening in question, the cooling device can be approved.
[0038] The passage of the tubes 7 through intermediate plate 24 need not take place with the usual clamp-fitting. The tubes 7 can be rolled in only lightly. Due to the substantially even pressure on both sides the intermediate plate 24 need not ensure an airtight sealing but indeed an oiltight sealing.
1. Cooling device comprising at least one gas or air cooling chamber and at least one
fluid cooling chamber, particularly oil cooling chamber, positioned adjacently, as
well as one or more tubes for passage of coolant, which tubes extend through both
the air cooling chamber and the fluid cooling chamber, in which between the adjacently
placed walls of the air cooling chamber and the fluid cooling chamber, a separation
chamber is placed through which the tubes extend, in which in the separation chamber
means are provided that engage on the outer surface of the tubes for intercepting
a fluid flow past said outer surface.
2. Cooling device according to claim 1, the interception means forming physical means
that have been placed in stationary connection or contact with the outer surface of
the tubes.
3. Cooling device according to claim 1, the interception means comprising an intermediate
plate, through which the tubes extend, the tubes preferably being sealingly accommodated
in the intermediate plate.
4. Cooling device according to any one of the preceding claims, the separation chamber
being provided with a discharge for leakage fluid.
5. Cooling device according to claim 3 or 4, the intermediate plate dividing the separation
chamber into two sub-chambers, means being provided for keeping both sub-chambers
at the same pressure.
6. Cooling device according to claim 5, the means for keeping both sub-chambers at the
same pressure comprising passages from each sub-chamber to the surroundings.
7. Cooling device according to claim 5, the means for keeping both sub-chambers at the
same pressure comprising passages from the one sub-chamber to the other, such as through
the intermediate plate.
8. Cooling device according to any one of the claims 3-7, the intermediate plate extending
substantially transverse to the tubes.
9. Cooling device according to any one of the preceding claims, the tubes extending substantially
horizontally.
10. Cooling device comprising least one gas or air cooling chamber and at least one fluid
cooling chamber, particularly oil cooling chamber, positioned adjacently, as well
as one or more tubes for passage of coolant, which tubes extend through both the air
cooling chamber and the fluid cooling chamber, which air cooling chamber and fluid
cooling chamber at least at the sides facing each other are limited by tube plates,
a separation chamber being formed between both tube plates, in which separation chamber
an intermediate plate has been placed which is positioned at a distance from both
tube plates, the tubes extending through the tube plates and the intermediate plate.
11. Cooling device according to claim 9, the spaces between the intermediate plate and
the tube plates being at the same pressure and preferably both being provided with
a discharge for leakage fluid from the fluid chamber.
12. Cooling chamber according to claim 10 or 11, comprising a housing having circumferential
walls surrounding the air cooling chamber and the fluid cooling chamber, the tube
plates extending in outward direction at least almost to the profile defined by the
circumferential walls, the tube plates preferably abutting the inner surface of the
circumferential walls via sealing rings.
13. Cooling device according to claim 10, 11 or 12, the tube plates and the intermediate
plate forming one mountable unity.
14. Cooling device comprising at least one gas or air cooling chamber and at least one
fluid cooling chamber, particularly oil cooling chamber, positioned adjacently, as
well as one or more tubes for passage of coolant, which tubes extend through both
the air cooling chamber and the fluid cooling chamber, as well as a housing having
circumferential walls surrounding the air cooling chamber and the fluid cooling chamber,
which air cooling chamber and the fluid cooling chamber at least at the sides facing
each other are limited by tube plates, a separation chamber being formed between both
tube plates, the tube plates extending in outward direction at least almost to the
inner surface of the profile defined by the circumferential walls.
15. Cooling device according to claim 14, the tube plates abutting the inner surface of
the circumferential walls via sealing rings.
16. Cooling device according to claim 14 or 15, the tube plates and the intermediate plate
forming one mountable unity, the tube plates and the intermediate plate preferably
being slidable as a unity in axial direction in and out of the cooling device.
17. Cooling device according to claim 16, the cooling device at one end being provided
with a distribution chamber for cooling water and with a further tube plate for limitation
of the distribution chamber to an adjacent cooling chamber, the further tube plate
forming one slidable unity with the intermediate plate and the tube plates.
18. Cooling device according to claim 16 or 17, an intermediate plate being placed in
the separation chamber which intermediate plate is positioned at a distance from both
tube plates, the tubes extending through the tube plates and the intermediate plate
and being clamped in them, the spaces between the intermediate plate and the tube
plates preferably being at the same pressure and both being provided with a discharge
for leakage fluid from the fluid cooling chamber.
19. Compressor provided a cooling device according to any one of the preceding claims.