(19)
(11) EP 0 878 627 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
05.03.2003 Bulletin 2003/10

(21) Application number: 98201582.8

(22) Date of filing: 12.05.1998
(51) International Patent Classification (IPC)7F04C 29/00, F04C 18/16

(54)

COMPRESSOR WITH AT LEAST ONE COMPRESSOR STAGE AND A MOISTURE SEPARATOR

VERDICHTER MIT ZUMINDEST EINER VERDICHTUNGSSTUFE UND EINEM FEUCHTIGKEITSABSCHEIDER

COMPRESSEUR AVEC AU MOINS UN ETAGE DE COMPRESSION ET UN SEPARATEUR D'HUMIDITE


(84) Designated Contracting States:
BE DE ES FR GB IT NL SE

(30) Priority: 16.05.1997 BE 9700428

(43) Date of publication of application:
18.11.1998 Bulletin 1998/47

(73) Proprietor: ATLAS COPCO AIRPOWER N.V.
2610 Wilrijk (BE)

(72) Inventors:
  • Goris, Joost
    2650 Edegem (BE)
  • Ernens, Philippe
    4880 Aubel (BE)

(74) Representative: Donné, Eddy 
Bureau M.F.J. Bockstael nv Arenbergstraat 13
2000 Antwerpen
2000 Antwerpen (BE)


(56) References cited: : 
EP-A- 0 854 290
US-A- 4 685 509
US-A- 2 204 814
US-A- 5 435 975
   
  • PATENT ABSTRACTS OF JAPAN vol. 9, no. 125 (C-283), 30 May 1985 & JP 60 014920 A (MITSUBISHI DENKI K.K.), 25 January 1985
   
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description


[0001] This invention relates to a compressor with at least one compressor stage and a moisture separator, whereby the compressor stage comprises a housing which is provided with an inlet for gas to be compressed and an outlet and comprises at least two cooperating compressor elements mounted in this housing, whereby at least one of which is rotatable.

[0002] In a multi-stage compressor, the gas compressed by a compressor stage, which is heated by this compression, is cooled in an intermediate cooler. During this cooling, the moisture present in this gas is condensed in the form of humidity particles which are carried along with the gas to the subsequent compressor stage.

[0003] In order to prevent that these moisture particles get into the subsequent compressor stage, in the known compressors mostly a moisture separator is placed between the intermediate cooler and the subsequent compressor stage.

[0004] These separate moisture separators, however, take a lot of space, are relatively expensive and have a limited separation capacity.

[0005] An intermediate cooler having a moisture separator in its outlets is disclosed in US-A-4.685.509.

[0006] Also for the first compressor stage or in a one-stage compressor, if moisture might be present in the gas to be compressed, a moisture separator is placed before this stage.

[0007] This invention aims at a compressor which excludes the aforementioned and other disadvantages and which, in a constructionally simple, compact and relatively cheap manner, makes it possible in a practical manner to separate moisture from the gas to be compressed.

[0008] According to the invention, this aim is achieved in that the inlet of the compressor stage is almost closed off by a rapidly rotating brush having a sufficiently low flow resistance for the gas in order to let the gas pass, but which keeps back moisture particles and other particles and whirls them radially away, which body is integrated in the housing.

[0009] EP-A-0.854.290, which is an earlier document but published after the filing date of this application, discloses a compressor stage the inlet of which is practically sealed by a fast rotating body made of cellular material with open cells which has sufficiently low resistance to let the gas through, but which retains moisture.

[0010] JP-A-60.014920 discloses a rotating moisture separator consisting of an open-pore type porous body, mounted in a pipe connected to for example a fan.

[0011] According to the invention, the body may be driven by the gas stream itself or by an external power source, but preferably, the inlet extends over a shaft with which the rotatable compressor element is beared in the housing, and the body is fixed on this shaft.

[0012] At the height of this body, the inlet may be provided with an enlargement forming a chamber wherein the whirled-away moisture is collected.

[0013] With the intention of better showing the characteristics of the invention, hereafter, by way of example without any limitative character, a preferred form of embodiment of a compressor with at least one compressor stage and a moisture separator according to the invention is described, with reference to the accompanying drawings, wherein:

figure 1 schematically represents a cross-section of one stage of a compressor according to the invention;

figure 2 represents the section which is indicated by F2 in figure 1, but in respect to another form of embodiment;

figure 3 represents in detail the section which is indicated by F2 in figure 1.



[0014] In figure 1, a compressor stage of a screw compressor is represented which substantially consists of a housing 1 in which two cooperating compressor elements 2 and 3, formed by screw-shaped rotors, are mounted in a rotatable manner.

[0015] Due to constructive purposes, the housing 1 consists of various parts which are fixed to each other, for example, by means of bolts.

[0016] The housing 1 determines an innermost space 4 in which the rotatable compressor elements 2 and 3 are situated.

[0017] The rotatable compressor element 2 consists of a screw-shaped body 5 which, at both extremities, is axially provided with a shaft 6, 7 respectively.

[0018] The shaft 6 is beared in a bearing 8 mounted in the housing 1 and connects directly or by the intermediary of a transmission to a drive motor, not represented in figure 1.

[0019] The shaft 7 is beared in a ball-bearing 9 integrated in the housing 1. At the outside of this ball-bearing 9, a ring 10 is clamped onto the shaft 7.

[0020] In an analogous manner, the rotatable compressor element 1 comprises a screw-shaped body 11 and, at both extremities thereof, a shaft 12, 13 respectively.

[0021] At one side, the shaft 12 is beared in a ball-bearing 14 which is fixed in the housing 1. At the outside of this ball-bearing 14, a clamping ring 10 is also clamped onto the shaft 12.

[0022] At the other side, the shaft 13 is beared in a bearing 15 which is also integrated in the housing 1.

[0023] This shaft 13 extends with a prolonged extremity 13A beyond the bearing 15, namely up into a chamber 16 which is formed in an end wall of the housing 1 and forms part of the inlet 16-17-18 which, thus, extends over the shaft 13.

[0024] The part 17 of the inlet connects the chamber 16 to the low-pressure side of the space 4, whereas the part 18 of the inlet, which has a smaller cross-section than the chamber 16, connects this chamber 16 to the exterior of the housing 1.

[0025] In the chamber 16, a body 19 in the form of a round disc is fixed at the prolonged extremity 13A of the shaft 13, which body is manufactured of cellular material with open cells.

[0026] The diameter of the body 19 is smaller than the diameter of the chamber 16, but larger than the diameter of the part 18 of the inlet 16-17-18 which, anyhow, is closed off almost completely by the body 19.

[0027] The body 19 has a sufficiently low flow resistance in order to let the gas to be compressed, in particular air, pass.

[0028] As shown in detail in figure 3 of the body 19 is a round and, for example, disc-shaped brush.

[0029] This brush preferably comprises steel bristles 26 which are directed almost radially and are fixed to a core 27, sitting, for example, clamped in a U-shaped groove. This core 27 is fixed, for example, glued, clamped of screwed on the prolonged extremity 13A of the shaft 13.

[0030] A discharge channel 20 which extends up to outward the housing 1, is connected to the chamber 16.

[0031] An outlet 21 for the compressed gas extends through the housing 1, at the side opposed to the inlet 16-17-18.

[0032] The working of the compressor is simple and as follows.

[0033] Due to the actuation, by means of the shaft 6, the body 5 is rotated which, in its turn, rotates the body 11 by means of gearwheels or by direct contact.

[0034] The gas to be compressed, which possibly is already coming from a preceding compressor stage, is brought through the inlet 16-17-18 into the chamber 4 and compressed by means of the compressor elements 2 and 3. The compressed gas is discharged through outlet 21.

[0035] Thereby, this gas to be compressed flows through the rotating body 19 or brush which is completely integrated in the housing 1, where the moisture particles are kept back and whirled radially out of the body 19.

[0036] The flow direction of the gas to be compressed is indicated by arrows 22.

[0037] Said moisture particles are collected at the bottom in the chamber 16, which is indicated by arrows 23, and discharged by the discharge channel 20.

[0038] The compressor described heretofore, thus, does not need a separate moisture separator. The body 19 forms a moisture separator integrated in the compressor stage, as a result of which the whole unit is compact and relatively cheap.

[0039] Instead of being mounted on the shaft 13 of the compressor element 3, the body 19 may be mounted on the shaft 6 of the compressor element 2, in which case the inlet has to extend over this shaft 6.

[0040] The compressor, a part of which is represented in figure 2, differs from the one represented in figure 1 in that means are provided to direct the flow of the gas to be compressed in the body 19 substantially in the transverse direction towards the shaft 13.

[0041] Said means are formed by a ring-shaped plate 24 which covers the side of the body 19 directed towards the part 18 of the inlet 16-17-18 and is fixed against this body, for example, glued, and by a second ring-shaped plate 25 which is fixed against the opposite side of the body 19 but which solely covers the exterior part of this side.

[0042] The gas to be compressed flows through the chamber 16 and along the exterior edge of the body 19 into this body 19 and leaves this body next to the shaft 13, after separating the liquid particles which are radially whirled outside.

[0043] The invention is not limited to screw compressors, but also applicable in other compressors, preferably with at least one rotatable compressor element upon which the body can be mounted.

[0044] The present invention is by no means limited to the forms of embodiment described heretofore and represented in the figures, on the contrary may such compressors be realized in various variants without leaving the scope of the invention.


Claims

1. Compressor with at least one compressor stage and a moisture separator, whereby the compressor stage comprises a housing (1) which is provided with an inlet (16-17-18) for gas to be compressed, and an outlet (21) and at least two cooperating compressor elements (2 and 3) mounted in this housing (1), at least one of which is rotatable, characterized in that the inlet (16-17-18) is almost closed off from the compressor stage by a rapidly rotating brush (19) having a sufficiently low flow resistance for the gas to be compressed in order to let this gas pass, but which keeps back moisture particles and other particles and whirls them radially away, which body (19) is integrated in the housing (1).
 
2. Compressor according to claim 1, characterized in that the inlet (16-17-18) extends over a shaft (13) with which the rotatable compressor element (3) is beared in the housing (1) and the brush (19) is fixed on this shaft (13).
 
3. Compressor according to claim 1 or 2, characterized in that the brush (19) is situated in a chamber (16) wich in that the body (19) is situated in a chamber (16) wich is formed by an enlargement of the inlet (16-17-18).
 
4. Compressor according to claim 3, characterized in that a discharge channel (20) is connected to the chamber (16).
 
5. Compressor according to any of the claims 1 to 4, characterized in that the brush (19) has the shape of a disc.
 
6. Compressor, according to any one of claims 1 to 5, characterized in that the brush (19) is a brush with almost radially directed bristles (26).
 
7. Compressor according to any one of the claims 1 to 6, characterized in that it is a screw compressor and the compressor stage comprises two rotatable, screw-shaped compressor elements (2 and 3) which, at both extremities, have a shaft (6-7-12-13) with which they are beared in the housing (1) and the brush (19) is mounted on one of these shafts (6 or 13) in the inlet (16-17-18).
 
8. Compressor according to any one of the preceding claims, characterized in that means are provided in order to let the stream of the gas to be compressed through the brush (19) flow, at least partially, into the transverse direction, towards the geometrical rotation axis of this brush (19).
 
9. Compressor according to claim 7, characterized in that the aforementioned means comprise at least one plate (24) which at least partially covers the side of the brush (19) directed towards the incoming gas to be compressed.
 
10. Compressor according to claim 9, characterized in that the aforementioned means comprise a plate (24) which at least partially covers the side of the brush (19) directed towards the incoming gas to be compressed, and a plate (25) partially covering the opposite side of the body (19).
 


Ansprüche

1. Verdichter mit zumindest einer Verdichtungsstufe und einem Feuchtigkeitsabscheider, wobei die Verdichtungsstufe ein mit einem Einlass (16-17-18) für zu verdichtendes Gas versehenes Gehäuse (1) umfasst, und einen Auslass (21) und zumindest zwei in diesem Gehäuse (1) montierte, zusammenwirkende Verdichtungselemente (2 und 3), wovon zumindest eines rotierbar ist, dadurch gekennzeichnet, dass der Einlass (16-17-18) von der Verdichtungsstufe durch eine rasch rotierende Bürste (19) nahezu abgeschlossen ist, die einen ausreichend niedrigen Strömungswiderstand für das zu verdichtende Gas hat, um dieses Gas passieren zu lassen, die jedoch Feuchtigkeitspartikel und andere Partikel zurückhält und sie radial wegschleudert, welcher Körper (19) im Gehäuse (1) integriert ist.
 
2. Verdichter gemäß Anspruch 1, dadurch gekennzeichnet, dass der Einlass (16-17-18) sich über eine Welle (13) erstreckt, mit der das rotierbare Verdichterelement (3) im Gehäuse (1) gelagert ist, und dass die Bürste (19) auf dieser Welle (13) befestigt ist.
 
3. Verdichter gemäß Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Bürste (19) sich in einer Kammer (16) befindet, die von einer Erweiterung des Einlasses (16-17-18) gebildet wird.
 
4. Verdichter gemäß Anspruch 3, dadurch gekennzeichnet, dass ein Abfuhrkanal (20) mit der Kammer (16) verbunden ist.
 
5. Verdichter gemäß einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass die Bürste (19) die Form einer Scheibe hat.
 
6. Verdichter gemäß einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass die Bürste (19) eine Bürste mit nahezu radial gerichteten Borsten (26) ist.
 
7. Verdichter gemäß einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, dass er ein Schraubenverdichter ist und die Verdichtungsstufe zwei rotierbare, schraubenförmige Verdichtungselemente (2 und 3) umfasst, die an beiden Enden eine Welle (6-7-12-13) aufweisen, womit sie im Gehäuse (1) gelagert sind, und dass die Bürste (19) an einer dieser Wellen (6 oder 13) im Einlass (16-17-18) montiert ist.
 
8. Verdichter gemäß einem der vorgenannten Ansprüche, dadurch gekennzeichnet, dass Mittel vorgesehen sind, um den Strom des zu verdichtenden Gases durch die Bürste (19) zumindest teilweise in Querrichtung strömen zu lassen, hin zur geometrischen Rotationsachse dieser Bürste (19).
 
9. Verdichter gemäß Anspruch 7, dadurch gekennzeichnet, dass die vorgenannten Mittel zumindest eine Platte (24) umfassen, die zumindest teilweise die zu dem eintretenden, zu verdichtenden Gas gerichtete Seite der Bürste (19) bedeckt.
 
10. Verdichter gemäß Anspruch 9, dadurch gekennzeichnet, dass die vorgenannten Mittel eine Platte (24) umfassen, die zumindest teilweise die zu dem eintretenden, zu verdichtenden Gas gerichtete Seite der Bürste (19) bedeckt, und eine Platte (25), die teilweise die gegenüberliegende Seite des Körpers (19) bedeckt.
 


Revendications

1. Compresseur comprenant au moins un étage de compresseur et un séparateur d'humidité, par lequel l'étage de compresseur contient un logement (1) muni d'une entrée (16 - 17 - 18) pour le gaz à comprimer et d'une sortie (21), et au moins deux éléments de compresseurs coopérants (2 et 3) montés dans ce logement (1), dont au moins un est un élément rotatif, caractérisé en ce que l'entrée (16 - 17 - 18) de l'étage de compresseur est presque fermée de manière hermétique à l'aide d'un balai à rotation rapide (19) qui possède une résistance suffisamment faible à l'écoulement pour que le gaz à comprimer puisse le traverser, mais qui retient les particules d'humidité et d'autres particules et les élimine par projection en direction radiale, ledit corps (19) étant incorporé dans le logement (1).
 
2. Compresseur selon la revendication 1, caractérisé en ce que l'entrée (16 - 17 - 18) s'étend par-dessus un arbre (13) avec lequel l'élément de compresseur rotatif (3) est monté sur palier dans le logement (1), et en ce que le balai (19) est fixé à cet arbre (13).
 
3. Compresseur selon la revendication 1 ou 2, caractérisé en ce que le balai (19) est situé dans une chambre (16) qui est constituée d'un élargissement de l'entrée (16 - 17 - 18).
 
4. Compresseur selon la revendication 3, caractérisé en ce qu'un petit conduit de décharge (20) est raccordé à la chambre (16).
 
5. Compresseur selon l'une quelconque des revendications 1 à 4, caractérisé en ce que le balai (19) prend la forme d'un disque.
 
6. Compresseur selon l'une quelconque des revendications 1 à 5, caractérisé en ce que le balai (19) est un balai comportant des poils de brosserie (26) orientés en direction pratiquement radiale.
 
7. Compresseur selon l'une quelconque des revendications 1 à 6, caractérisé en ce qu'il s'agit d'un compresseur du type à vis et en ce que l'étage de compresseur comprend deux éléments de compresseurs rotatifs du type à vis (2 et 3) qui possèdent un arbre (6 - 7 - 12 - 13) à leurs deux extrémités avec lequel ils sont montés sur paliers dans le logement (1), et en ce que le balai (19) est monté sur un de ces arbres (6 ou 13) dans l'entrée (16 - 17 - 18).
 
8. Compresseur selon l'une quelconque des revendications précédentes, caractérisé en ce qu'on prévoit des moyens pour faire en sorte que le courant de gaz qui doit être comprimé s'écoule au moins en partie en direction transversale à travers le balai (19), à proximité de l'axe géométrique de rotation dudit balai (19).
 
9. Compresseur selon la revendication 7, caractérisé en ce que les moyens susmentionnés comprennent au moins une plaque (24) qui recouvre au moins en partie le côté du balai (19) tourné vers le gaz entrant à comprimer.
 
10. Compresseur selon la revendication 9, caractérisé en ce que les moyens susmentionnés contiennent une plaque (24) qui recouvre au moins en partie le côté du balai (19) tourné vers le gaz entrant à comprimer et une plaque (25) qui recouvre en partie le côté opposé du balai (19).
 




Drawing