Liquid-injected compressor or expander element and method for controlling the liquid injection of a compressor or expander device

Abstract

Liquid-injected compressor element or expander element with a housing that comprises a rotor chamber in which at least on rotor is rotatably affixed, whereby the element is further provided with a connection for an injection circuit for the injection of liquid into the element, whereby the connection to the injection circuit is realised by means of an injection point in the housing that opens into the first compression chamber or expansion chamber. The connection to the injection circuit is additionally realised by means of an additional injection point in the housing that opens into a second or subsequent compression chamber or expansion chamber.

Claims

1. A liquid-injected compressor or expander comprising: a housing that comprises a rotor chamber in which two rotors are rotatably affixed, said rotors rotating with lobes of the rotors being able to mate together, wherein the compressor or expander further comprises a connection connected to an injection circuit for the injection of a lubricating liquid into the compressor or expander, wherein the connection to the injection circuit is realised by means of a first injection point in the housing that always opens into a first compression chamber or expansion chamber, wherein the connection to the injection circuit is additionally realised by means of a second injection point in the housing that opens into a second or subsequent compression chamber or expansion chamber, wherein the first compression chamber or expansion chamber is a gas chamber that is closed off after a gas inlet of the rotor chamber and said second or subsequent compression chamber or expansion chamber being formed after at least one rotor of the two rotors has rotated one pitch or revolution from the gas inlet, wherein the first injection point is located on a first helical line formed by a tip of a lobe of a rotor that separates the first compression chamber or expansion chamber from the second or subsequent compression chamber or expansion chamber and the second injection point is located on a second helical line formed by a second tip of a second or subsequent lobe of the rotor that separates the second or subsequent compression chamber of expansion chamber from a successive compression chamber, wherein the first injection point and the second injection point, further comprises a number of sub-injection points that each open into the first compression chamber or expansion chamber, or the second or subsequent compression chamber or expansion chamber, respectively.

2. The liquid-injected compressor or expander according to claim 1, wherein there is at least one additional injection point, each at least one additional injection point opens into a different subsequent compression chamber or expansion chamber.

3. The liquid-injected compressor or expander according to claim 2, wherein each at least one additional injection point further comprises a number of sub-injection points that each open into the respective different subsequent compression chamber or expansion chamber.

4. The liquid-injected compressor or expander according to claim 1, wherein the two rotors are rotatably affixed in the rotor chamber and the second injection point is provided for each rotor.

5. The liquid-injected compressor or expander according to claim 1, wherein a quantity of lubricating liquid that is injected via the first injection point and the second injection point are able to be controlled.

6. The liquid-injected compressor or expander according to claim 1, wherein a temperature of the lubricating liquid that is injected via the first injection point and the second injection point are able to be controlled.

7. A method for controlling liquid injection of a compressor installation or expander installation, w herein the compressor installation or expander installation comprises at least one compressor or expander, w herein the at least one compressor or expander comprises a housing that comprises a rotor chamber in which two rotors are rotatably affixed, said rotors rotating with lobes of the rotors mated together, wherein lubricating liquid is injected into the compressor or expander, wherein the method comprises the step of: providing at least two liquid supplies to the rotor chamber of the housing, wherein one liquid supply of the at least two liquid supplies is always injected into a first compression chamber or expansion chamber and the other of the at least two liquid supplies is injected into a second or subsequent compression chamber or expansion chamber, wherein the first compression chamber or expansion chamber is a gas chamber that is closed off after a gas inlet of the rotor chamber and said second or subsequent compression chamber or expansion chamber being formed after at least one rotor of the two rotors has rotated one pitch or revolution from the gas inlet, wherein a first injection point is located on a first helical line formed by a tip of a lobe of a rotor that separates the first compression chamber or expansion chamber from the second or subsequent compression chamber or expansion chamber and a second injection point is located on a second helical line formed by a second tip of a second or subsequent lobe of the rotor that separates the second or subsequent compression chamber of expansion chamber from a successive compression chamber, wherein the first injection point and the second injection point, further comprises a number of sub-injection points that each open into the first, or second or subsequent compression chamber or expansion chamber, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) With the intention of better showing the characteristics of the invention, a few preferred variants of a liquid-injected compressor element or expander element according to the invention and a method for controlling the liquid injection of a compressor device or expander device are described hereinafter, by a way of an example without any limiting nature, with reference to the accompanying drawings wherein:

(2) FIG. 1 schematically shows a compressor element according to the invention;

(3) FIG. 2 schematically shows an expander element according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) The compressor element 1 according to the invention schematically shown in FIG. 1 comprises a housing 2 that defines a rotor chamber 3.

(5) The rotor chamber 3 is provided with a gas inlet 4 and a gas outlet 5 for compressed gas.

(6) One or more rotors 6 are rotatably affixed in the housing 2. In this case there are two rotors 6 that rotate with their lobes 7 mated together.

(7) The rotors 6 are rotatably affixed in the housing 2 by means of bearings 8, in this case in the form of two bearings that are affixed on the shafts 9 of the rotors 6. The bearings 8 can be realised by means of roller bearings or can be realised in the form of plain bearings.

(8) Furthermore the compressor element 1 is provided with a connection 10 for an injection circuit for the injection of liquid into the compressor element 1.

(9) This liquid can for example be synthetic oil or water or otherwise, but the invention is not limited to this as such.

(10) According to the invention the connection 10 to the injection circuit is realised by means of an injection point 11a in the housing 2 that is connected to an injection pipe 12a of the injection circuit and which opens into the first compression chamber 13.

(11) The first compression chamber 13 is the gas chamber that is closed off just after the inlet, as shown in FIG. 1. It is at this moment that the compression will start.

(12) This chamber remains the first compression chamber 13 until the moment that the rotors 6 have rotated one cycle or pitch further. At this moment this chamber becomes the second compression chamber 14.

(13) Note that at this time a new first compression chamber 13 is formed, by the chamber that was previously the inlet chamber 15 that was connected to the inlet 4.

(14) The first injection point 11a is chosen such that it always opens into the first compression chamber 13 irrespective of the position of the rotors 6 so that this injection point 11a can never come into contact with the inlet 4 and the inlet chamber 15.

(15) In this way oil is prevented from being able to get in the inlet chamber 15.

(16) According to the invention, the connection 10 to the injection circuit is additionally realised by means of an additional injection point 11b in the housing 2 that is connected to a second injection pipe 12b of the injection circuit and which opens into a second compression chamber 14 or subsequent compression chamber.

(17) The second compression chamber 14 is, as already explained above, located one pitch or revolution of the rotors 6 from the inlet.

(18) In this case both the injection point 11a and the additional injection point 11b are located on a helical line 16a, 16b, 16c that is formed by the tips of the rotor lobes 7 that separate successive compression chambers 13, 14 from one another.

(19) Note that these helical lines 16a, 16b, 16c are traced out, so to speak, by the tips of the rotor lobes 7 on the housing 2, at least on the walls of the rotor chamber 3.

(20) These helical lines 16a, 16b are shown in FIG. 1. The inlet helical line 16a separates the inlet chamber 15 that is connected to the inlet 4 of the first compression chamber 13. The next helical line 16b separates the first compression chamber 13 from the second compression chamber 14.

(21) The injection point 11a lies on this helical line 16b. As a result it can be ensured that the oil that is injected via this injection point 11a can never get into the inlet 4.

(22) The additional injection point 11b is on a subsequent helical line 16c that separates the second compression chamber 14 from the third compression chamber 17.

(23) As already stated, two rotors 6 are rotatably affixed in the rotor chamber 9, whereby in this case an additional injection point 11b is provided for each rotor 6, i.e. at the location of or at the side of each rotor 6.

(24) In this way each of these injection points 11b will lie on a helical line 16c that is traced out on the walls of the rotor chamber 3 by the tips of the lobes 7 of the rotor 6 concerned.

(25) Such a compressor element 1 can be used in a compressor device, not shown in the drawings, that is provided with an injection circuit 18 that is connected to the injection points 11a, 11b, whereby this injection circuit can be controlled such that the quantity and temperature of the liquid that is injected can be controlled.

(26) The operation of the compressor element 1 is very simple and as follows.

(27) During the operation of the compressor element 1 a gas, for example air, will be drawn into the rotor chamber 3 via the gas inlet 4, more specifically into the inlet chamber 15, whereby due to the operation of the rotors 6 the gas will be compressed and leave the compressor element 1 via the outlet 5.

(28) During operation, liquid will be injected into the rotor chamber 3 to provide lubrication, sealing and cooling.

(29) The liquid is injected into the first compression chamber 13 via the injection point 11a and into the second compression chamber 14 via the additional injection point 11b.

(30) The quantity of liquid that is supplied via the injection pipes 12a, 12b can be adjusted according to the prevailing requirements at that time.

(31) For example the injection flows can be driven on/off, whereby either no liquid is injected or a predetermined quantity is injected.

(32) It is also possible that the temperature of the liquid that is injected via the injection point 11a and the additional injection point 11b is controlled, whereby the control can be done separately for both injection points 11a, 11b.

(33) The Belgian patent application No. 2016/5147 of the same applicant goes into this more deeply.

(34) It is possible that the injection point 11a or additional injection point 11b is made up of a number of sub-injection points.

(35) Each of the sub-injection points 19 that form the injection point 11a open into the first compressor chamber 13 and are preferably located on the aforementioned helical line 16b that separates the first compression chamber 13 from the second compression chamber 14.

(36) Analogously the sub-injection points that form the additional injection point 11b open into the second compression chamber 14 and are preferably located on the helical line 16c between the second compression chamber 14 and the third compression chamber 17.

(37) It is also possible that there is more than one additional injection point 11b whereby these additional injection points lib each open into a different compression chamber 14, 17, i.e. in addition to the additional injection point 11b that opens into the second compression chamber 14, there are also one or more additional injection points 11b that open into the third compression chamber 17 or a subsequent compression chamber.

(38) In this way liquid will be injected into the first, second and third compression chamber 13, 14, 17.

(39) It is also possible that there is only one additional injection point 11b that opens into the third compression chamber 17 or subsequent compression chamber and in other words that liquid is injected into the first compression chamber 13 into the third compression chamber 17, but not into the second compression chamber 14.

(40) FIG. 2 shows an expander element 1 according to the invention.

(41) This embodiment essentially differs from the previous one by the fact that the inlet 4 and the outlet 5 are swapped around as it were. This means that the inlet helix 16a and the first expansion chamber 13 are located on the other side of the element 1.

(42) The form of the inlet 4 is also different: the inlet 4 has both an axial and a radial section. The invention is not limited to this as such, and inlets and outlets for compressor elements and expander elements can have radial and axial sections.

(43) The injection point 11a is located on the helical line 16b that separates the first expansion chamber 13 from the second expansion chamber 14 and the additional injection point 11b is located on the subsequent helical line 16c.

(44) The injection point 11a will inject liquid into the first expansion chamber 13. It is this gas chamber that is just separated from the inlet 4 of the expander element 1.

(45) When the rotors 6 have turned one pitch or revolution further, this first expansion chamber 13 becomes the second expansion chamber 14 in which the additional injection point 11b will inject liquid.

(46) The aforementioned additional elements and variants can be applied mutatis mutandis for an expander element.

(47) Although the foregoing is described for a compressor element or expander element 1, the invention is also applicable to a vacuum pump, which in essence is also a compressor element 1 or compressor device.

(48) The present invention is by no means limited to the embodiments described as an example and shown in the drawings, but a liquid-injected compressor element or expander element according to the invention and a method for controlling the liquid injection of a compressor device or expander device can be realised according to different variants without departing from the scope of the invention.