Compressor or vacuum pump device, a liquid return system for such a compressor or vacuum pump device and a method for draining liquid from a gearbox of such a compressor or vacuum pump device

Abstract

A liquid-injected compressor or vacuum pump device with a liquid-injected compressor or vacuum pump element (2), which includes a liquid return system (7), a motor (4) to drive the compressor or vacuum pumping element (2), a gearbox (3) provided between the motor (4) and the liquid-injected compressor or vacuum pump element (2), and a liquid separator vessel (5) in fluid connection with an outlet (6) of the compressor or vacuum pump element (2). The liquid return system (7) includes a main body (8) with a chamber in which a first compressed gas flow (11) from the liquid separator vessel (5) and a second fluid flow (15) from the gearbox (3) are mixed together to form a third fluid flow (20). The third fluid flow (20) leaves the chamber via an outlet (16) and is directed into the liquid-injected compressor or vacuum pump element (2) via the injection point (17).

Claims

1. A compressor or vacuum pump device with a liquid-injected compressor or vacuum pump element (2), which compressor or vacuum pump device (1) further comprises a liquid return system (7), a motor (4) to drive the liquid-injected compressor or vacuum pump element (2), a gearbox (3) provided between the motor (4) and the liquid-injected compressor or vacuum pump element (2), and a liquid separator vessel (5) in fluid connection with an outlet (6) of the liquid-injected compressor or vacuum pump element (2), wherein the liquid return system (7) comprises a main body (8) with a chamber provided with an outlet (16) and a first inlet (9), wherein the first inlet (9) is in fluid connection with the liquid separator vessel (5) and receives a first compressed gas flow (11) from the liquid separator vessel (5), and wherein the outlet (16) is in fluid connection with an injection point (17) of the liquid-injected compressor or vacuum pump element (2), wherein the chamber is also provided with a second inlet (12) which is in fluid connection with the gearbox (3) and receives a second fluid flow (15) from the gearbox (3), and wherein the chamber is configured to mix the aforementioned first compressed gas flow (11) and a second fluid flow (15) together into a third fluid flow (20), which third fluid flow (20) leaves the chamber via the outlet (16) and is directed via the injection point (17) into the liquid-injected compressor or vacuum pump element (2).

2. The compressor or vacuum pump device according to claim 1, wherein the second inlet (12) is in fluid connection with the gearbox (3) by means of a suction line (13).

3. The compressor or vacuum pump device according to claim 2, wherein the suction line (13) is made of a transparent material.

4. The compressor or vacuum pump device according to claim 2, wherein the suction line (13) is provided with a sensor (21) which is configured to detect a presence of liquid in the suction line (13).

5. The compressor or vacuum pump device according to claim 4, wherein the sensor (21) is an optical sensor.

6. The compressor or vacuum pump device according to claim 4, wherein the sensor (21) is provided with a transmitter (22) that is configured to send a signal that can be received by a receiver.

7. The compressor or vacuum pump device according to claim 6, wherein the signal is a wireless signal.

8. The compressor or vacuum pump device according to claim 1, wherein the liquid-injected compressor or vacuum pump element (2) is an oil-injected compressor or vacuum pump element.

9. The compressor or vacuum pump device according to claim 1, wherein the liquid-injected compressor or vacuum pump element (2) is a water-injected compressor or vacuum pump element.

10. The compressor or vacuum pump device according to claim 1, wherein the liquid return system (7) further comprises a relief valve (25) integrated on the main body (8).

11. The compressor or vacuum pump device according to claim 1, wherein the liquid return system (7) is configured to control a flow rate of the third fluid flow (20).

12. The compressor or vacuum pump device according to claim 1, wherein the liquid return system (7) further comprises an underpressure generating means (19), which underpressure generating means (19) generates an underpressure in the gearbox (3).

13. The compressor or vacuum pump device according to claim 12, wherein the underpressure generating means (19) is provided in the main body (8) of the liquid return system (7) as a venturi ejector.

14. The compressor or vacuum pump device according to claim 1, wherein the second inlet (12) is in fluid connection with the gearbox (3) via a non-return valve (14), which non-return valve (14) allows only a fluid flow from the gearbox (3) to the liquid return system (7).

15. The liquid return system for the compressor or the vacuum pumping device according to claim 1, which compressor or vacuum pump device (1) further comprises the motor (4) to drive the liquid-injected compressor or vacuum pump element (2), the gearbox (3) provided between the motor (4) and the liquid-injected compressor or vacuum pump element (2), and the liquid separator vessel (5) in fluid connection with the outlet (6) of the liquid-injected compressor or vacuum pump element (2), wherein the liquid return system (7) comprises the main body (8) with the chamber provided with the outlet (16) and the first inlet (9), wherein the first inlet (9) is configured to be in fluid connection with the liquid separator vessel (5) and to receive the first compressed gas flow (11), and wherein the outlet (16) is configured to be in fluid connection with the injection point (17) of the liquid-injected compressor or vacuum pump element (2), wherein the chamber is further provided with the second inlet (12) which is configured to be in fluid connection with the gearbox (3) and to receive the second fluid flow (15), wherein the chamber is configured to mix the aforementioned first compressed gas flow (11) and second fluid flow (15) together into the third fluid flow (20), which third fluid flow (20) leaves the chamber via the outlet (16), and wherein the liquid return system (7) is configured to control a flow rate of the third fluid flow (20).

16. The liquid return system according to claim 15, wherein it further comprises a relief valve (25) integrated on the main body (8).

17. The liquid return system according to claim 15, wherein it further comprises an underpressure generating means (19) provided in the main body (8), which underpressure generating means (19) is configured to generate an underpressure in the gearbox (3).

18. The liquid return system according to claim 17, wherein underpressure generating means (19) is a venturi ejector.

19. The liquid return system according to claim 18, wherein it is designed as a modular element in relation to the compressor or vacuum pump device (1) in such a way that the liquid return system (7) can be detachably arranged in fluid connection with the compressor or vacuum pumping device (1) and that after detaching the liquid return system (7) the compressor or vacuum pump device (1) can continue to function under normal operating conditions.

20. A method for draining liquid from a gearbox (3) of a compressor or vacuum pump device (1) with a liquid-injected compressor or vacuum pump element (2), wherein the compressor or vacuum pump device (1) further comprises a motor (4) for driving the liquid-injected compressor or vacuum pump element (2) and a liquid separator vessel (5) in fluid connection with an outlet (6) of the liquid-injected compressor or vacuum pump element (2), wherein the gearbox (3) is provided between the motor (4) and the liquid-injected compressor or vacuum pump element (2), wherein by means of a liquid return system (7) liquid is removed from the gearbox (3) by a fluid connection between said liquid return system (7) and the gearbox (3), and mixed with a liquid flow from the liquid separator vessel (5), after which the liquid mixed with this fluid flow is directed into the liquid-injected compressor or vacuum pump element (2).

21. The method according to claim 20, wherein an underpressure generating means (19) is used to generate an underpressure in the gearbox (3).

22. The method according to claim 20 wherein a presence of liquid in the fluid connection between the liquid return system (7) and the gearbox (3) can be detected by means of a sensor (21).

23. The method according to claim 22, wherein the presence of liquid in the fluid connection between the liquid return system (7) and the gearbox (3) is detected by an optical sensor.

24. The method according to claim 22, wherein the sensor (21) sends a signal via a transmitter (22) with information about the aforementioned presence of liquid in the fluid connection between the liquid return system (7) and the gearbox (3), which signal can be received by a receiver.

25. The method according to claim 24, wherein the signal is a wireless signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) With the intention of better demonstrating the characteristics of the invention, as an example without any restrictive character, a preferred embodiment of the compressor or vacuum pump device according to the invention and of the liquid return system for such a compressor or vacuum pump device are described below, with reference to the drawings, wherein:

(2) FIG. 1 shows a compressor or vacuum pump device with a liquid-injected compressor or vacuum pump element according to the invention;

(3) FIG. 2 shows an isometric view of a liquid return system according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) FIG. 1 shows a compressor or vacuum pump device 1 according to the invention with a liquid-injected compressor or vacuum pump element 2.

(5) The compressor or vacuum pump element 2 is driven by a motor 4 via a transmission in a gearbox 3.

(6) The compressor or vacuum pump device 1 further comprises a liquid separator vessel 5 which is in fluid connection with an outlet 6 of the liquid-injected compressor or vacuum pump element 2.

(7) In addition, the compressor or vacuum pump device 1 comprises a liquid return system 7 which comprises a main body 8.

(8) A first inlet 9 of the main body 8 of the liquid return system 7 is in fluid connection with the liquid separator vessel 5, preferably via a throttling means 10, and receives a first compressed gas flow 11 coming from this liquid separator vessel 5.

(9) By means of the throttling means 10, a flow rate of the first compressed gas flow 11 coming from the liquid separator vessel 5 to the main body 8 can be regulated.

(10) A second inlet 12 of the main body 8 of the liquid return system 7 is also in fluid connection with the gearbox 3 via a suction line 13, preferably via a non-return valve 14, such that a second fluid flow 15 can only pass through the suction line 13 from gearbox 3 to the liquid return system 7.

(11) Furthermore, an outlet 16 of the main body 8 of the liquid return system 7 is in fluid connection with an injection point 17 of the compressor or vacuum pump element 2.

(12) This injection point 17 is typically located in the inlet valve 18 of the compressor or vacuum pump element 2.

(13) The main body 8 includes an underpressure generating means 19 which is configured to generate an underpressure in the gearbox 3 through which the second fluid flow 15 is sucked in from the gearbox 3.

(14) In the main body 8, the first compressed gas flow 11 and the second fluid flow 15 are mixed into a third fluid flow 20 which is sent via outlet 16 to injection point 17 of the compressor or vacuum pump element 2.

(15) This way, liquid which enters the gearbox 3 due to failure of seals in the compressor or vacuum pump device 1 is sucked out of the gearbox 3 and recovered to the compressor or vacuum pump element 2.

(16) The suction line 13 is provided with a sensor 21, preferably an optical sensor, which is configured to detect a presence of liquid in the suction line 13 and, consequently, seal failure.

(17) Sensor 21 is provided with a transmitter 22 configured to send a wireless signal that can be received by an external receiver.

(18) This external receiver may be, for example, a computer or smartphone which can be used to remotely follow up on and/or control operational conditions of the compressor or vacuum pump device 1.

(19) In addition to a sensor 21 for detecting the presence of liquid in the suction line 13, it is of course not ruled out that the suction line 13 may be provided with additional sensors, for instance to analyze degradation of liquid that may be present in the suction line 13, which may indicate the need to replace and/or regenerate this liquid in the compressor or vacuum pump installation 1.

(20) FIG. 2 shows the main body 8 of the liquid return system 7 according to the invention in more detail.

(21) The main body 8 includes a chamber provided with the outlet 16 for the third fluid flow 20, the first inlet 9 for the first compressed gas flow 11 and the second inlet 12 for the second fluid flow 15.

(22) More specifically, the first inlet 9 is configured to be in fluid connection with the liquid separator vessel 5 and to receive the first compressed gas flow 11, the second inlet 12 to be in fluid connection with the gearbox 3 and to receive the second fluid flow 15, and the outlet 16 to be in fluid connection with an injection point 17 of the liquid-injected compressor or vacuum pump element 2 and to lead the third fluid flow 20 out of the chamber.

(23) The main body 8 may be provided with an additional outlet 23, which additional outlet 23 may then be in fluid connection with the compressor or vacuum pump element 2 at a position downstream of the inlet valve 18.

(24) The main body 8 may also be provided with one or more boreholes 24, which ensure that the main body 8 can be attached to a component of the compressor or vacuum pump device 1, for instance by means of a bolted connection.

(25) A relief valve 25 may be integrated on the main body 8. If a pressure of the first compressed gas flow 11 coming from the liquid separator vessel 5 exceeds a predefined limit value, this first compressed gas flow 11, possibly mixed with the second fluid flow 15 coming from the gearbox 3, may be blown off via the relief valve 25.

(26) In addition, a control unit 26 may be integrated on the main body 8. By means of this control unit 26, a flow rate of the third fluid flow 20, which is fed via outlet 16 to the injection point 17 of the liquid-injected compressor or vacuum pump element 2, can be controlled.

(27) The invention is by no means limited to the embodiments described as examples and shown in the figures, but a compressor or vacuum pump device and a liquid return system for such a compressor or vacuum pump device can be realized in all forms, dimensions and versions without exceeding the scope of protection of the invention as defined in the claims.