Device for degassing and / or dehydrating hydraulic oil and hydraulic equipment having the same

Abstract

The invention relates to a device for degassing and / or dehydrating hydraulic oil, which device has a flow gun, which has a throttling point and a flow channel in the form of a tube located downstream of the throttling point, through which the hydraulic oil flows under high pressure, wherein the oil quantity flowing through the throttling point and the flow cross section of the throttling point are coordinated with each other so that a cavitation region or a supercavitation region is formed downstream of the throttling point, and wherein the flow channel has a cross section that is significantly larger than the flow cross section of the throttling point. For quiet operation of the device, it is provided that the flow gun is held in a decoupling module, by which the flow gun can be fixed to a tank in a vibration-decoupled manner. The invention also relates to a hydraulic device with a tank and with such a device.

Description

Technical Field

[0001] The invention relates to a device for degassing and / or dehydrating hydraulic oil, the device comprising a flow lance having a throttle point and a flow channel in the form of a tube downstream of the throttle point, through which the hydraulic oil flows under high pressure, wherein the oil quantity flowing through the throttle point and the flow cross section of the throttle point are coordinated with one another in such a way that a cavitation region or a supercavitation region is formed downstream of the throttle point, and wherein the flow channel has a cross section which is significantly larger than the flow cross section of the throttle point. The invention also relates to a hydraulic system having a tank and having a device of the type described above. Background Art

[0002] Air contained in hydraulic fluids represents a problem in hydraulic systems for various reasons. The higher the proportion of free or undissolved air, the greater the inherently undesirable compressibility of the hydraulic oil. If air bubbles are also contained in the hydraulic oil pumped by the pump, this can lead to poor efficiency and to high noise levels. The more free air there is in the hydraulic oil, the faster the hydraulic oil ages. Usually attempts are made to lift the gas bubbles that occur in the hydraulic system out of the hydraulic oil in the storage container and to vent them by means of large-sized storage containers with a correspondingly long residence time of the hydraulic pressure medium. This process can take place relatively slowly, depending on the size of the gas bubbles.

[0003] Devices of this type are known, for example, from DE 10 2015 216 173 A1, DE 10 2015 216 174 A1 or DE 10 2016 216 002 A1.

[0004] It is known from DE 10 2015 216 174 A1 to provide an intermittent or regulated operation for a degassing device, wherein the oxygen content or air content in the hydraulic oil is determined for the regulated operation and the degassing device is operated according to fixed limit values.

[0005] DE 102015216173 A1 discloses enclosing the fluid gun with a casing having an opening leading directly to the atmosphere. As a result, the gas bubbles should not first enter the main tank, but directly into the atmosphere. However, the casing must be separated as much as possible from the main tank for this purpose. An overflow pipe is provided as a fluid connection to the main tank, which overflow pipe is designed in such a way that at least nearly the entire flow channel is immersed in the hydraulic oil. This keeps the noise level very low during operation of the device.

[0006] DE 102016216002 A1 describes how a device of the type described at the beginning of this article can be used for both degassing and dehydrating hydraulic oil. Here, too, by appropriately selecting the pressure loss and volume flow through the throttling portion, a cavitation zone or supercavitation zone (Superkavitationszone) is formed downstream of the throttling portion, in which a coherent area is formed by oil vapor and air. Bubbles are generated when the oil condenses, and the bubbles can be separated gently. In order to make the device also usable for dehydrating hydraulic oil, it is based on the idea that air can absorb a certain amount of water. The water previously dissolved in the oil is therefore in the form of molecules in the bubbles and separated from the bubbles. In order to make the separation rate of water independent of the air contained in the oil, DE 102016216002 A1 recommends that additional air be introduced into the (super) cavitation zone from the outside downstream of the throttling portion. This causes a large number of extremely small bubbles to be generated from the introduced air, and the bubbles have a bubble surface that is extremely large in the sum of all bubbles. The amount of water diffused from the oil into the gas bubbles generated by the air introduced from the outside and thus the water separation rate increases with the size of the gas bubble surface. Due to the negative pressure in the cavitation area, the air can be introduced directly from the surrounding environment. However, it is also possible to provide an air supply device in order to introduce compressed air, hot air, cold air, dry air, i.e. air with different parameter values ​​from the surrounding air.

[0007] In order to better separate the gas bubbles and to adjust a constant air content in the hydraulic system, air can be introduced from the outside during pulse operation, so that cavitation or supercavitation is used to alternately degas while separating a small amount of water, or bubbles can be generated from additionally sucked in air or actively introduced air and the water can be separated to a large extent.

[0008] The flow gun is excited by the physical effect of cavitation or supercavitation. Vibrations occur which are transmitted in known arrangements to the walls of the main tank, so that these walls are excited to emit sound waves. This is also the case, although to a lesser extent, when the flow channel is ensured to be immersed in the oil as far as possible by the enclosure. Summary of the invention

[0009] The object of the present invention is to provide a device which has the features mentioned at the outset and which enables efficient, cost-effective and rapid degassing and / or dehydration of hydraulic oil with an extremely low noise level.

[0010] In a device for degassing and / or dehydrating hydraulic oil having the features described at the beginning of this article, the object is achieved in that the flow gun is held in a decoupling module, by which the flow gun can be fixed to the tank in a vibration-decoupled manner. The device can be held on the tank without a direct rigid connection due to the decoupling module. The vibrations of the flow gun are therefore not transmitted to the wall of the tank and the device works particularly quietly. A hydraulic device having a tank and a device according to the invention inserted into an opening of the tank is particularly quiet.

[0011] The device according to the invention for degassing and / or dehydrating can be further designed in an advantageous manner.

[0012] The flow lance is advantageously partially surrounded radially by the decoupling module and is also supported axially on the decoupling module.

[0013] The decoupling module can be designed as a buffer with a channel for accommodating the flow lance, in particular as a decoupling bushing, and have an inner collar on which the flow lance rests in the axial direction.

[0014] It is conceivable that the damper is provided for being directly fixed on the tank. For this reason, there is a channel for fixing the screw on the damper.

[0015] It can be provided that the buffer is compressed in the axial direction and the flow gun is thereby securely surrounded and held. However, the compression should not be too strong, since otherwise the sound decoupling would be weakened.

[0016] It seems particularly advantageous if the buffer is surrounded by a housing provided for fastening to the tank. The housing can have a hollow pivot surrounding the jet lance, with which the housing can be inserted into the opening of the tank. The housing increases the stability of the device.

[0017] In order to operate the device intermittently at fixed intervals or in a controlled manner, a valve or valves may be provided. Such valves are advantageously arranged on the decoupling module.

[0018] In order that the bubbles generated in the (super)cavitation region are not widely dispersed in the tank used by the device, it is advantageous if the flow channel ends in an enclosure which is closed at its first end before the flow channel, surrounds the flow channel over at least a portion of its length and is open at its second end within the length of the flow channel. The enclosure can be connected to the flow channel by means of a tab so that the flow gun and the enclosure can be operated and mounted together. For noise reduction reasons, it may be advantageous if the open second end of the enclosure is below the fluid level in the tank. The enclosure serves to deflect the bubbles coming out of the flow channel immediately in the direction of the fluid surface of the tank in order to limit the distribution of the bubbles in the tank and to promote air separation. In order that a fountain does not appear on the fluid surface, deflection plates can be arranged at certain intervals before the open end of the enclosure, which deflect the fluid flow coming out of the enclosure horizontally approximately below the fluid surface.

[0019] The device advantageously comprises a moisture sensor for determining the water contained in the hydraulic oil and can be operated as a function of the water content in order to keep the water content below a certain limit value.

[0020] In addition to the humidity sensor or even without such a humidity sensor, the device can also include an oxygen sensor for determining the air contained in the hydraulic oil and can be operated in accordance with the determined air content in such a way that the oxygen partial pressure is between 160 mbar and 190 mbar. Since air contents with an oxygen partial pressure below 160 mbar cause a "hardness" of the hydraulic oil, which can increase the wear of the pump, no degassing is performed at oxygen partial pressures below 160 mbar. Air contents with oxygen partial pressures exceeding 190 mbar cause premature aging and excessive compressibility of the hydraulic oil. Degassing is therefore performed at oxygen partial pressures exceeding 190 mbar. The oxygen partial pressure in the atmosphere is 212 mbar at sea level. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings show several exemplary embodiments of the device according to the invention for degassing and / or dehydrating hydraulic oil. The invention will now be explained in more detail with reference to the drawings. In the drawings:

[0022] Figure 1 In the strongly simplified figure, a first embodiment, mainly for degassing hydraulic oil, is shown with a flow lance and a rubber buffer;

[0023] Figure 2 A second embodiment is also shown in a greatly simplified manner, with and Figure 1 The embodiment has the same degassing function and has a surrounding piece;

[0024] Figure 3 The same is also shown in a greatly simplified manner Figure 3A third embodiment similar to the embodiment of the present invention has an air input from the surrounding environment to dehydrate the hydraulic oil;

[0025] Figure 4 The same is also shown in a greatly simplified manner Figure 3 A fourth embodiment similar to the embodiment of , with controlled air input from the ambient environment to deaerate and dehydrate the hydraulic oil;

[0026] Figure 5 The same is also shown in a greatly simplified manner Figure 3 A fifth embodiment similar to the embodiment of the invention has a controlled air input from the surrounding environment to deaerate and dehydrate the hydraulic oil in a switchable manner;

[0027] Figure 6 A sixth embodiment is shown with structural design details in the area of ​​the first type of rubber buffer surrounding the flow gun; and

[0028] Figure 7 A seventh embodiment is shown with structural design details in the area of ​​the second type of rubber buffer surrounding the flow lance. DETAILED DESCRIPTION

[0029] according to Figure 1 The device 11 for degassing hydraulic oil comprises a flow gun 12 and a decoupling module in the form of a bushing-like buffer made of elastic material, in particular a rubber buffer 13, into which the flow gun 12 is inserted. The flow gun in turn comprises a right-angled inlet pipe 14 and a straight flow pipe 15, between which a nozzle 16 is embedded in the area where the rubber buffer surrounds the flow gun 12. The flow pipe 15 is arranged essentially vertically together with one side of the inlet pipe 14 and extends into the tank 19 through an opening 17 in the horizontal tank wall 18 of the tank 19. In this tank, the flow pipe ends below the oil level 20.

[0030] The rubber buffer 13 has an outer circumference which is larger than the diameter of the opening 17 in the tank and is placed in a sealing manner on the tank wall 18. A plurality of bores (not shown in detail) are passed through the rubber buffer 13 at equal angular distances from one another, through which fixing screws 21 are inserted and screwed into the tank wall 18. The rubber buffer 13 is thus fixed to the tank wall 18 and the fluid lance 12 is also fixed to the tank wall via the rubber buffer in a structure-borne sound-proof manner. The vibrations of the fluid lance caused by the (super) cavitation in the flow tube 15 are therefore not transmitted or are only transmitted in a weakened form to the tank wall 18 and thus to the entire tank.

[0031] In press Figure 2 In the embodiment of the present invention, the structure of the flow gun 12 having the right-angle bent inflow pipe 14, the nozzle 16, the flow pipe 15 and the rubber buffer 13 is similar to that of the flow gun 12 according to the embodiment of the present invention. Figure 1 The structure of the embodiment is the same as that of Figure 1 The embodiment of the embodiment of the invention differs in that the outer diameter of the inlet pipe is slightly smaller than the outer diameter of the flow pipe. The flow pipe 15 is surrounded by a shroud 25 in the tank 19, which is configured as a tube, which is closed before the open end of the flow pipe 15 immersed in the oil in the tank and is mechanically connected to the flow pipe 15 by a tab 26 and thus forms a unit with the flow gun. The tube 25 is open at the top and ends below the oil level 20, so that the oil level is not higher in the tube than in the tank. The shroud is used to deflect the air bubbles coming out of the flow pipe 15 directly to the oil surface in the tank and thus limit the distribution of the air bubbles in the tank and promote air separation. In order not to generate a fountain above the oil surface, a plate 27 is installed horizontally on the flow pipe 15 at intervals before the open end of the shroud 25 but below the oil level 20, which deflects the fluid flow horizontally almost below the oil surface.

[0032] In degassing operation, the pump draws hydraulic oil from the tank 19 and delivers it to the inlet pipe 14. The hydraulic oil flows through the nozzle 16, where a pressure drop is generated by the nozzle, which is determined by the delivery rate of the pump and the flow resistance of the nozzle. The delivery rate and the flow resistance are coordinated with each other in such a way that a liquid beam is generated downstream of the nozzle 16 by supercavitation, which is surrounded by a coherent area consisting of liquid vapor, in the present case oil vapor, and air at a certain distance. Due to the condensation of the evaporated oil, an area with foam is connected to this area, which also surrounds the central liquid beam. Finally, all the oil condenses and a liquid is obtained, in which large air bubbles are contained. The mixture of liquid oil and air bubbles thus generated enters the enclosure 25 at the end of the flow pipe 15. The generated air bubbles rise upward in the enclosure 25, around the plate 27 to the oil surface 20 and into the space above the oil surface and leave the tank 19 outward through corresponding openings into the surrounding environment.

[0033] During the degassing process of the hydraulic oil, dehydration also occurs to a small extent, since the air contained in the gas bubbles can absorb water and this water is transferred from the tank to the outside along with the air bubbles. In order to increase the separation rate of water from the hydraulic oil, Figure 3In the embodiment of the present invention, an air path 30 is provided, which passes through the rubber buffer 13 and through the wall of the flow tube 15. The air path 30 is open to the surroundings and leads into the interior of the flow tube 15 downstream of the nozzle 16. During operation, when the hydraulic oil flows through the nozzle 16, the air additionally input from the outside now enters the cavitation area through the air path 30. Additional water is absorbed from the steam area by this air and is guided to the outside. Due to the negative pressure in the cavitation area, air can be directly input from the surroundings through the air path 30. However, an air supply device can also be provided to introduce compressed air, hot air, cold air, dry air, that is, air with parameter values ​​different from those of the surrounding air.

[0034] according to Figure 3 The device is particularly suitable for dehydrating hydraulic oil.

[0035] In contrast, the design Figure 4 , i.e., with which the hydraulic oil can be degassed and dehydrated very effectively. For this purpose, a switching valve 35 is provided on the rubber buffer 13, which is embedded in the air path 30. In the idle position, the switching valve 35 interrupts the air path 30, so that no air can enter the cavity region from the surroundings. By driving the electromagnet, the switching valve 35 can be brought into the switching position, in which the air path 30 is open. Air then enters the cavity region from the surroundings. Figure 4 The device 11 is thus in the rest position of the switching valve 35 and in the Figure 2 The device 11 works in the same way. First, the hydraulic oil is degassed. On the contrary, if the switch valve 35 is opened, then the Figure 4 The device 11 is as follows Figure 3 The hydraulic oil is first dehydrated.

[0036] exist Figure 5 The device 11 shown in Figure 4 The device also has a switching valve 35, which can be used to close and open the air path 30. Figure 5 The device 11 and the Figure 4 The device can be used to degas the hydraulic oil as well as to dehydrate the hydraulic oil.

[0037] according to Figure 5The device 11 also has an additional switching valve 36, which is embedded in the inlet pipe 14 and can interrupt the inflow of hydraulic oil to the nozzle 16 without switching off the pump. By means of the switching valve 36, it is thus possible to realize intermittent operation of the device 11 with a fixed operating time and a fixed idle time, wherein the time can be adjustable. However, by means of the switching valve 36, a regulated operation of the device 11 is also realized in such a way that the air content of the hydraulic oil is kept between two limit values, for example in the range between an oxygen partial pressure of 160 mbar and 190 mbar, and the humidity is kept below the limit value. In order to determine the air content of the hydraulic oil in the tank 19, an oxygen sensor 37 is provided. In order to determine the humidity or water content in the hydraulic oil, a humidity sensor 38 is provided. The electrical output signals of the two sensors 37 and 38 are sent to a regulator 39, which can drive the electromagnets of the switching valves 35 and 36.

[0038] If, for example, the oxygen sensor 37 determines that the hydraulic oil has such a high air content that the oxygen partial pressure is 190 mbar, the switch valve 36 is opened by the regulator 39, while the switch valve 35 remains closed. The hydraulic oil with a high air content now flows to the nozzle 16. This hydraulic oil is already combined with the air pressure. Figure 2 If the air content is so low that the oxygen partial pressure is only 160 mbar, the switch valve 36 is closed.

[0039] If the humidity sensor 38 confirms that the humidity of the hydraulic oil is about to exceed a certain value, the two switch valves 35 and 36 are opened by the regulator 39. The hydraulic oil with high humidity now flows to the nozzle 16. This hydraulic oil is combined with the Figure 3 Dehydrated in the manner described in the device.

[0040] In press Figure 6 and 7 In both embodiments, the flow gun 12 has a substantially cylindrical nozzle unit 45, through which a channel 46 with bore sections 47, 48 and 49 are passed, the diameters of which are different from one another. The flow tube 15 is inserted into the bore section 47, which extends into the tank 19 through the opening 17 in the tank wall 18 and extends below the oil level 20. The bore section 49 is provided for inserting the inlet tube into the nozzle unit 45. The nozzle 16 is screwed into the central bore section 48 having the smallest diameter of the three bore sections. A radial bore 50 opens into the bore section 48 downstream of the nozzle 16, through which radial bore the air from the surrounding environment can enter the flow channel downstream of the nozzle 16 and corresponds to the radial bore 50. Figures 3 to 5 The air path 30 of the embodiment of FIG. Figure 6 and 7In an embodiment, the air path does not extend through the elastic material.

[0041] Between the radial bore 50 and the end of the nozzle unit facing the tank wall 18, the nozzle unit 45 is surrounded by a bushing-like rubber buffer 51, which acts as a coupling module, and is inserted into the latter. This rubber buffer is in turn accommodated by a rigid housing 52 having a bottom 53, in which an opening 54 is centrally located, through which the flow tube 15 passes. On the outside of the bottom 53, the housing 52 has an annular projection or hollow pivot 55 around the opening 54, the outer diameter of which is slightly smaller than the diameter of the opening 17 in the tank wall 18 and the housing 52 is inserted into the opening 17 with the projection or hollow pivot in such a way that the bottom 53 rests on the tank wall 18. The opening 17 can be sealed by a radial seal between the projection 55 and the wall of the opening 17 and / or by an axial seal between the bottom 53 and the tank wall 18.

[0042] In press Figure 6 In the exemplary embodiment of the present invention, the rubber buffer 51 has an inner flange 56, on which the nozzle unit 45 rests with its end facing the tank wall 18. On the side of the housing opposite the base 53, the housing is closed by a perforated disk 57 which extends snugly around the nozzle unit 45 and is fixed to the housing 51 by screws 58, so that the rubber buffer 51 is protected and held in the housing 52. Before the perforated disk 57 is screwed on, the rubber buffer 51 can protrude slightly from the edge of the housing 51, so that it is slightly compressed when the perforated disk is screwed on. The flow gun 12 is thus sufficiently fixed. The compression should be only as strong as is necessary, because it reduces the effect of the sound decoupling between the flow gun 12 and the housing 52 and thus the tank 19.

[0043] In press Figure 7 In the embodiment of the present invention, the rubber buffer 51 is a bushing without an inner flange. A perforated disc 59 is in contact with each of the two end sides of the rubber buffer 51. A long clamping screw 60 passes through one perforated disc 59 and through the rubber buffer 51 and is thus screwed into the other perforated disc 59. Depending on how tightly the clamping screw 60 is tightened, the rubber buffer 51 is compressed more or less. This compression creates a composite structure between the flow gun 12, the rubber buffer 51 and the housing 52 that meets the requirements in terms of a firm connection. A ring 61 made of elastic material is located between the bottom 53 of the housing 52 and the nozzle unit 45.

[0044] according to Figure 6 and 7 Functions and functions of the embodiments Figure 3 The functions of the embodiments are the same.

[0045] The disclosed device for degassing and / or dehydrating hydraulic oil has the following advantages in particular:

[0046] It is extremely compactly constructed;

[0047] It does not require its own pressure supply mechanism, so the cost is very low and few components are required;

[0048] Modular use is possible. This means that a plurality of identically designed devices can be used for a greater degassing and dehydration capacity and the space required is nevertheless small;

[0049] The device is scalable. That is, due to simple components, it can be easily adapted to a greater degassing and dehydration capacity.

[0050] The device is acoustically decoupled from the tank so that the tank is excited to vibrate and thus the noise generated by cavitation and supercavitation is very small.

[0051] List of reference numerals:

[0052] 11. Installation

[0053] 12 Flowing Gun

[0054] 13 Rubber buffer

[0055] 14 Inlet pipe

[0056] 15 Flow tube

[0057] 16 Nozzle

[0058] 17 Openings in 18

[0059] 18 Tank wall

[0060] 19 Tanks

[0061] 20 Oil level

[0062] 21 Fixing screw

[0063] 25 pieces

[0064] 26 Splice

[0065] 27 Plate

[0066] 30 Air Path

[0067] 35 Switch valve

[0068] 36 Switch valve

[0069] 37 Oxygen sensor

[0070] 38 Humidity Sensor

[0071] 39 Regulator

[0072] 45 Nozzle Unit

[0073] 46 in 45 channels

[0074] Drilling section of 47 46

[0075] 48 46 drilling section

[0076] Drilling section of 49 46

[0077] 50 radial drilling in 45

[0078] 51 Rubber buffer

[0079] 52 Housing

[0080] 53 52 bottom

[0081] 54 53 openings

[0082] 55 annular protrusion surrounding 54

[0083] 56 inner flange on 51

[0084] 57 Disc with holes

[0085] 58 Screws

[0086] 59 disc with holes

[0087] 60 Clamping screw

[0088] 61 rings.

Claims

1. A device for degassing and / or dehydrating hydraulic oil, the device comprising: A flow gun (12) having a throttle (16) and a flow channel (15) in the form of a tube downstream of the throttle (16), through which the hydraulic oil flows under high pressure, in, The amount of oil flowing through the throttle point (16) and the flow cross section of the throttle point (16) are coordinated with each other in such a way that a cavitation region or a supercavitation region is formed downstream of the throttle point (16). and wherein the flow channel (15) has a cross section which is significantly larger than the flow cross section of the throttling point (16), The invention is characterized in that the flow gun (12) is held in a decoupling module, by means of which the flow gun can be fixed to the tank (19) in a vibration-decoupled manner, wherein the flow gun (12) is partially surrounded by the decoupling module in radial direction, The decoupling module is designed as a rubber buffer (13) having a channel for accommodating the flow gun (12). An air path is provided, which passes through the rubber buffer (13) and through the wall of the flow channel (15). wherein the flow channel (15) is surrounded in the tank (19) by a casing (25) which is designed as a tube, wherein the casing is closed before the open end of the flow channel (15) which is immersed in the oil in the tank and is mechanically connected to the flow channel (15) via a web (26) and thus forms a unit with the flow gun, This allows for a modular use of the device.

2. The device according to claim 1, wherein: The flow gun (12) is supported on the decoupling module in the axial direction.

3. The device according to claim 1 or 2, wherein: The rubber buffer (13) has a channel for a fixing screw (21).

4. The device according to claim 1 or 2, wherein: The rubber buffer (13) is compressed in the axial direction.

5. The device according to claim 1 or 2, wherein: At least one valve (35, 36) is arranged on the decoupling module.

6. The device according to claim 1 or 2, wherein: The flow channel (15) terminates in an enclosure (25) which surrounds the flow channel (15) over at least a portion of its length and is open at its end within the length of the flow channel (15).

7. The device according to claim 6, wherein: A deflector plate (27) is arranged at a certain interval in front of the open end of the enclosure (25).

8. The device according to claim 1 or 2, wherein: The device comprises a moisture sensor (38) for determining the water contained in the hydraulic oil, and the device can be operated as a function of the water content.

9. The device according to claim 1 or 2, wherein: The device comprises an oxygen sensor (37) for determining the air contained in the hydraulic oil, and the device can be operated as a function of the determined air content in such a way that the oxygen partial pressure is between 160 mbar and 190 mbar.

10. A hydraulic system comprising a tank (19) and a device (11) according to any one of claims 1 to 9, wherein: The device (11) is inserted into an opening (17) of a tank (19).

Images