Oil-gas cyclone diffusion separation device and hydraulic system

Abstract

The application discloses an oil-gas cyclone diffusion separation device and a hydraulic system, which comprises, from top to bottom, an overflow diffusion chamber, an overflow pipe, a cyclone chamber cylindrical section, a cyclone chamber conical section and an underflow diffusion chamber, the cyclone chamber cylindrical section is connected with an oil return inlet pipe, the bottom end of the cyclone chamber conical section is provided with an underflow port for connecting the underflow diffusion chamber, the cyclone chamber cylindrical section comprises a cylindrical cyclone chamber, the cylindrical cyclone chamber is provided with a spiral downflow channel lower wall surface and a cyclone wall in the form of an Archimedes spiral, the cylindrical cyclone chamber, the spiral downflow channel lower wall surface and the cyclone wall enclose a spiral downflow channel, a pre-swirl inlet on the spiral downflow channel is communicated with the oil return inlet pipe, the inner wall surface of the cyclone wall is tangent to the inner wall surface of the cylindrical cyclone chamber, and the center line of the pre-swirl inlet is arranged along the tangential direction of the cylindrical cyclone chamber. The oil-gas cyclone diffusion separation device can efficiently and quickly remove the gas bubbles in the oil, has low oil return pressure, high separation efficiency and a wide flow matching range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas separation of hydraulic systems, in particular, relates to an oil-gas cyclone diffusion separation device. In addition, the present application also relates to a hydraulic system comprising the above-mentioned oil-gas cyclone diffusion separation device. BACKGROUND

[0002] During the normal operation of the hydraulic system, especially in the open hydraulic system, due to the fluctuation of the oil tank liquid level, the insufficient oil suction pressure of the hydraulic pump, the poor sealing or aging of the sealing in the pipeline and many other factors, air is easily mixed into the hydraulic system. A part of the air mixed into the hydraulic system will dissolve in the oil, becoming dissolved gas, and the undissolved air in the oil becomes free gas bubbles. The dissolved gas in the oil inevitably passes through various valves, throttle holes and other components. When the oil velocity increases and the pressure decreases at the valve port, the dissolved gas will separate out to become free gas bubbles when the static pressure is lower than the oil-air separation pressure. When the oil flows turbulently in the pipeline, the free gas bubbles in the oil will continuously mix, aggregate and split, and eventually become spherical bubbles with a diameter of 0.2-0.5mm suspended in the oil.

[0003] The free gas bubbles mixed into the oil will seriously threaten the safety of the hydraulic system. On the one hand, the free gas bubbles are easy to cause cavitation of the hydraulic pump, produce vibration and noise, damage the core components such as the distribution plate, and thus reduce the service life of the pump; on the other hand, the free gas bubbles will reduce the specific heat capacity and thermal conductivity of the oil-gas mixture, causing the oil temperature to rise and not being able to cool down quickly, accelerating the oxidation of the oil and the aging of the sealing; in addition, the free gas bubbles will increase the compressibility of the oil-gas mixture, thereby reducing the accuracy and reliability of the hydraulic system and affecting the normal operation of the hydraulic system.

[0004] To reduce the adverse effects of bubbles on the hydraulic system, the hydraulic oil tank undertakes the mission of removing bubbles. In the prior art, the oil tank design usually adopts the measures of long-width-height ratio design, setting a partition, staggering the oil suction pipe and increasing the oil suction filter to reduce the bubble content of the oil suction port. The principle is to increase the flow path of the oil in the oil tank, prolong the residence time of the oil, and make more bubbles move upward to the liquid surface and break due to buoyancy. However, relying solely on the natural defoaming of the oil tank not only has very limited defoaming capacity, but also requires more space to arrange the partition and the oil suction pipe, which also violates the lightweight demand of the hydraulic oil tank.

[0005] Another way is to increase special devices to separate bubbles, such as relying on external power to rotate to form a cyclone to separate bubbles, or to use its own structure to generate a cyclone to separate bubbles. The former requires additional power devices, which increases energy consumption and mass. For the latter, due to its structure and principle, the cyclone must have two outlets, namely the overflow pipe and the underflow port; the bubbles discharged from the overflow pipe are not 100% volume fraction of air, but oil-gas mixture, and the bubble content is still low. The existing device often extends the overflow pipe above the liquid surface, and the underflow port is opposite to the bottom of the oil tank; on the one hand, the oil-gas mixture overflowed from the overflow pipe to the liquid surface of the oil tank will cause splashing of droplets, causing liquid surface fluctuation, thereby entraining air; on the other hand, the underflow port will cause the sediment at the bottom of the oil tank to be suspended again. Moreover, the existing device increases the back pressure of the oil return, which doubles the oil return pressure, and is only suitable for small flow conditions. SUMMARY

[0006] The present application provides an oil-gas cyclone diffusion separation device and a hydraulic system to solve the technical problems of high oil return pressure, low bubble separation efficiency and small flow adaptation range of the existing hydraulic oil tank oil-gas separation device.

[0007] According to one aspect of the present application, an oil-gas cyclone diffusion separation device is provided, comprising an overflow diffusion chamber, an overflow pipe, a cyclone chamber cylindrical section, a cyclone chamber conical section and a underflow diffusion chamber connected in sequence from top to bottom, the top end of the cyclone chamber cylindrical section is connected with the overflow diffusion chamber through the overflow pipe, the cyclone chamber cylindrical section is connected with a oil return inlet pipe, the bottom end of the cyclone chamber conical section is provided with a underflow port for connecting the underflow diffusion chamber, the cyclone chamber cylindrical section comprises a cylindrical cyclone chamber, a spiral downflow channel lower wall and a cyclone wall in the form of Archimedes spiral are arranged on the cylindrical cyclone chamber, the cylindrical cyclone chamber, the spiral downflow channel lower wall and the cyclone wall enclose a spiral downflow channel, a pre-swirl inlet on the spiral downflow channel is connected with the oil return inlet pipe, the inner wall of the cyclone wall is tangent to the inner wall of the cylindrical cyclone chamber, and the center line of the pre-swirl inlet is arranged along the tangential direction of the cylindrical cyclone chamber.

[0008] Further, one end of the oil return inlet pipe is used to connect a circular pipe opening of an oil return pipe, and the other end is a square pipe opening used to connect the pre-swirl inlet.

[0009] Further, the bottom end of the overflow pipe is inserted into the cylindrical cyclone chamber, the depth of the bottom end of the overflow pipe inserted into the cylindrical cyclone chamber is greater than or equal to 1 / 2 of the height of the cylindrical cyclone chamber, and the diameter of the overflow pipe is greater than or equal to 1 / 2 of the diameter of the cylindrical cyclone chamber.

[0010] Further, the overflow diffusion chamber comprises a first cylindrical filter screen, the bottom end of the first cylindrical filter screen is connected with the overflow pipe, and the top end is provided with a circular filter screen.

[0011] Further, the first supporting strip is arranged on the first cylindrical filter screen.

[0012] Further, the circular filter screen is detachably connected with the top end of the first cylindrical filter screen through a circular ring cover plate.

[0013] Further, the height of the conical section of the cyclone chamber is 3-4 times of the height of the cylindrical section of the cyclone chamber, and the diameter of the underflow port is greater than or equal to 1 / 2 times of the diameter of the cylindrical cyclone chamber.

[0014] Further, the underflow diffusion chamber comprises a second cylindrical filter screen, and the top end of the second cylindrical filter screen is communicated with the underflow port through a circular ring connecting plate.

[0015] Further, the bottom end of the second cylindrical filter screen is connected with a circular bottom plate, and a second supporting strip is arranged on the second cylindrical filter screen.

[0016] According to another aspect of the present application, there is also provided a hydraulic system comprising the oil-gas cyclone diffusion separation device.

[0017] The present application has the following beneficial effects:

[0018] Firstly, the present application adopts Archimedes spiral line to design a pre-rotation inlet and a spiral down-flow channel, and the spiral down-flow structure can adjust the direction of the inlet velocity from the tangent direction to the tangent oblique downward direction, which can not only prevent the interference between the newly-incoming oil and the oil in the cyclone, but also guide the oil to flow downward along the direction of the underflow port, so that the flow in the cyclone area is more stable, the generation of turbulence is effectively avoided, the energy loss is greatly reduced, the centripetal acceleration of the oil is generated, which is much greater than the gravitational acceleration, the free-state bubbles are gathered to the central low-pressure area under the action of the buoyancy, and the oil with a high gas content in the central area is rotated upward to the overflow pipe under the joint action of the buoyancy and the extrusion of the conical section of the cyclone chamber, while the oil with a low gas content in the periphery is rotated downward to the underflow port under the action of gravity.

[0019] Secondly, the present application designs diffusion filter devices outside the overflow port and the underflow port, which can not only gather the small bubbles in the oil-gas mixture into large bubbles to increase the upward velocity of the bubbles, but also stabilize the velocity of the oil filtered by the filter screen, thereby prolonging the residence time of the oil and shortening the upward distance of the bubbles, and without causing great disturbance to the liquid surface, so that the entrained gas in the liquid surface fluctuation and the secondary mixing of the gas and the liquid can be avoided.

[0020] Third, the oil return treatment mode of the application combines cyclone separation and diffusion filtration, and has two processing modes: for small flow conditions (flow less than 60L / min), the filtration diffusion plays a dominant role, and the cyclone effect is not significant. Since the device is located below the oil tank liquid surface as a whole, the outlet pressure of the underflow diffusion chamber is greater than that of the overflow diffusion chamber, most of the oil-gas mixture is directly introduced into the overflow diffusion chamber after cyclone in the cyclone chamber cylindrical section 2, and then enters the oil tank after filtration and diffusion, and finally separates the bubbles on the liquid surface. The return oil pressure is lower than 0.1bar, and the separation efficiency is higher than 85%; for large flow conditions (flow greater than or equal to 60L / min), the cyclone speed is large, the cyclone effect is significant, the flow distribution is small, and the cyclone and filtration diffusion functions are both played. The cyclone effect makes the oil liquid with high gas content in the central region enter the oil tank below the overflow diffusion chamber, while the oil liquid with low gas content in the periphery enters the oil tank bottom from the underflow diffusion chamber. The return oil pressure is lower than 0.2bar, and the separation efficiency is higher than 95%. The internal flow area of the structure of the application is large, and the filter screen area is large, so the return oil pressure of the application is lower than that of the traditional return oil filter. In summary, the application has the advantages of low return oil pressure, high bubble separation efficiency, wide flow adaptation range, etc.

[0021] In addition to the purposes, features and advantages described above, the application has other purposes, features and advantages. The application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings that form a part of this application are used to provide a further understanding of the application, and the illustrative embodiments of the application and their description serve to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0023] Figure 1 is a structural schematic diagram of the oil-gas cyclone diffusion separation device of the preferred embodiment of the application;

[0024] Figure 2 is a cross-sectional schematic diagram (axial section) of the oil-gas cyclone diffusion separation device of the preferred embodiment of the application;

[0025] Figure 3 is an inlet cross-sectional schematic diagram of the oil-gas cyclone diffusion separation device of the preferred embodiment of the application;

[0026] Figure 4 is an axial cross-sectional velocity vector diagram of the cyclone chamber under small flow conditions;

[0027] Figure 5 is an axial cross-sectional velocity vector diagram of the cyclone chamber under large flow conditions.

[0028] LEGEND:

[0029] 1. Return oil inlet pipe; 11. Circular pipe opening; 12. Square pipe opening; 2. Cylindrical section of swirl chamber; 21. Pre-swirl inlet; 22. Spiral lower swirl channel; 23. Lower wall of spiral lower swirl channel; 24. Cylindrical swirl chamber; 25. Swirl wall; 3. Overflow pipe; 4. Overflow diffuser chamber; 41. First cylindrical filter screen; 42. First support bar; 43. Circular cover plate; 44. Circular filter screen; 5. Conical section of swirl chamber; 6. Underflow port; 7. Underflow diffuser chamber; 71. Circular connecting plate; 72. Second support bar; 73. Second cylindrical filter screen; 74. Circular bottom plate. Detailed Implementation

[0030] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0031] Please refer to the following: Figures 1 to 5 The oil-gas cyclone diffusion separation device of this embodiment includes, from top to bottom, an overflow diffusion chamber 4, an overflow pipe 3, a cylindrical section 2 of the cyclone chamber, a conical section 5 of the cyclone chamber, and an underflow diffusion chamber 7. The top of the cylindrical section 2 of the cyclone chamber is connected to the overflow diffusion chamber 4 through the overflow pipe 3. A return oil inlet pipe 1 is connected to the cylindrical section 2 of the cyclone chamber. The bottom end of the conical section 5 of the cyclone chamber is provided with an underflow port 6 for connecting to the underflow diffusion chamber 7. The cylindrical section 2 of the cyclone chamber includes a cylindrical cyclone chamber 2. 4. The cylindrical vortex chamber 24 is provided with a spiral lower vortex channel lower wall surface 23 and an Archimedean spiral-shaped vortex wall 25. The cylindrical vortex chamber 24, the spiral lower vortex channel lower wall surface 23 and the vortex wall 25 form a spiral lower vortex channel 22. The pre-swirl inlet 21 on the spiral lower vortex channel 22 is connected to the return oil inlet pipe 1. The inner wall surface of the vortex wall 25 is tangent to the inner wall surface of the cylindrical vortex chamber 24. The center line of the pre-swirl inlet 21 is arranged along the tangent of the cylindrical vortex chamber 24.

[0032] The spiral wall 25 has an Archimedean spiral shape with a gradually decreasing radius. After 180°, the inner wall of the spiral wall 25 is tangent to the inner wall of the cylindrical vortex chamber 24. The top plate of the cylindrical vortex chamber 24, the lower wall 23 of the spiral downward vortex channel, and the spiral wall 25 form the spiral downward vortex channel 22. The upper end of the spiral downward vortex channel 22 is a pre-swirl inlet 21 for introducing oil. The lower wall 23 of the spiral downward vortex channel is located on the inner wall of the cylindrical vortex chamber 24 and extends towards the overflow pipe 3. The intersection of the lower wall 23 of the spiral downward vortex channel and the cylindrical vortex chamber 24 is a cylindrical spiral. When the oil at the inlet just enters the cylindrical vortex chamber 24 and the velocity is still relatively high, the spiral downward vortex structure can adjust the velocity direction from the tangential direction to an oblique downward direction along the tangent. The swirling motion guides the oil downwards along the underflow direction, effectively preventing turbulence and ensuring smooth and efficient swirling. Furthermore, it prevents interference between the newly introduced oil and the swirling oil, resulting in more stable flow in the swirling region and significantly reducing energy loss. During operation, the oil enters the pre-swirling inlet 21 of the cylindrical section 2 of the swirling chamber from the return oil inlet pipe 1. The cylindrical section 2 of the swirling chamber employs a spiral downward swirling channel 22, combining a spiral downward swirling flow with an Archimedean spiral ingress. This efficiently generates swirling flow while preventing interference between the newly introduced oil and the swirling oil. Through the swirling action, the oil generates a centripetal acceleration far greater than the acceleration due to gravity, causing free-state bubbles to move towards the center under buoyancy. In the overflow chamber, under the combined effects of buoyancy and the compression of the conical section, the oil with a higher gas content in the central area rotates upwards towards the overflow pipe 3, while the oil with a lower gas content in the periphery rotates downwards towards the bottom outlet 6 under the influence of gravity. The oil with a higher gas content entering the overflow diffuser chamber 4 from the overflow pipe 3 undergoes a process where, under the action of the filter screen, small bubbles coalesce into larger bubbles, increasing their upward velocity. Simultaneously, the velocity of the oil passing through the filter screen is reduced, extending the residence time and efficiently and quickly removing air bubbles from the oil. The overflow diffuser chamber 4 can be located below the liquid surface or partially exposed above the filter screen because the velocity of the oil flowing out of the overflow diffuser chamber 4 is below 0.4 m / s and relatively stable, minimizing impact on the liquid surface. Interference is avoided by preventing gas from being carried in by liquid surface fluctuations; the underflow diffuser 7 is located at the bottom of the oil tank. On the one hand, the underflow diffuser 7 can also keep the oil velocity below 0.4m / s, thus preventing the oil from stirring up the bottom sediment; on the other hand, it has a larger back pressure than the overflow diffuser 4. Under low flow conditions, most of the oil carries the majority of the gas into the oil tank from the overflow diffuser 4, and very little oil enters the oil tank from the underflow diffuser 7. Under high flow conditions, after the oil undergoes swirling, a portion of the oil carries the majority of the gas into the oil tank from the overflow diffuser 4, while another portion carries a small portion of the gas into the bottom of the oil tank from the underflow diffuser 7. Whether under low or high flow conditions, the device in this case has a high processing capacity.

[0033] Because this embodiment uses a return oil treatment method that combines cyclone separation and diffusion filtration, for low-flow conditions (flow rate less than 60L / min), filtration and diffusion play a dominant role, with return oil pressure below 0.1 bar and separation efficiency above 85%. For high-flow conditions (flow rate greater than or equal to 60L / min), both cyclone and filtration / diffusion functions are utilized. The cyclone effect causes oil with a higher gas content in the central area to enter the tank below the liquid surface from the overflow diffusion chamber, while oil with a lower gas content in the periphery enters the tank bottom from the underflow diffusion chamber. The return oil pressure is below 0.2 bar and the separation efficiency is above 95%. It has the advantages of low return oil pressure, high separation efficiency, wide flow rate adaptability, and overall optimization with the tank. Optionally, the intersection of the lower wall 23 of the spiral swirling channel and the cylindrical swirling chamber 24 is a cylindrical helix. If the pitch of the cylindrical helix is ​​too small, the downward swirling intensity will decrease; if the pitch is too large, the downward swirling intensity will be greater, causing the oil to rapidly change direction and mix, thus reducing the swirling separation effect. Therefore, a pitch of 1.5 to 2.5 times the height of the cylindrical section 2 of the swirling chamber is more suitable. Optionally, the pitch of the cylindrical helix is ​​twice the height of the cylindrical section 2 of the swirling chamber.

[0034] like Figure 1 , Figure 2 and Figure 3 As shown, in this embodiment, one end of the return oil inlet pipe 1 is used to connect to the circular port 11 of the return oil pipe, and the other end is a square port 12 used to connect to the pre-swirl inlet 21. The return oil inlet pipe 1 is generally constricted, with one end being circular and having a large flow area, connected to the return oil pipe; the other end is rectangular and has a smaller flow area, connected to the pre-swirl inlet 21 in a tangential manner, reducing unnecessary pressure loss; the inlet, which gradually narrows from circular to rectangular, can accelerate the oil, increasing the velocity of the oil entering the cylindrical section 2 of the swirl chamber, and, in conjunction with the pre-swirl inlet 21, forms a gradually expanding and contracting structure. Through pressure changes, some easily precipitated dissolved gases are precipitated into free gas bubbles, which are then separated by subsequent structures, making the gas separation in the oil more thorough.

[0035] like Figure 1 , Figure 2 and Figure 3As shown, in this embodiment, the bottom end of the overflow pipe 3 is inserted into the cylindrical cyclone chamber 24. The size and insertion depth of the overflow pipe 3 are important factors affecting the performance of the cyclone separator. The outer wall of the overflow pipe 3 facilitates the rotation of the internal flow field. Increasing the insertion depth helps to drive the rotation of the fluid in the lower part. If the insertion depth is too deep, the oil with a high gas content in the middle cannot enter the overflow pipe 3 in time, thereby reducing the separation efficiency. If the diameter of the overflow pipe 3 is too small, it will increase the return oil pressure and reduce the separation efficiency. If it is too large, regardless of the flow rate, most of the oil will enter the oil tank from the overflow pipe 3, and the cyclone structure will not play its role. Therefore, the depth to which the bottom end of the overflow pipe 3 is inserted into the cylindrical cyclone chamber 24 should be between 1 / 4 and 3 / 4 of the height of the cylindrical cyclone chamber 24, and the diameter of the overflow pipe 3 should be between 3 / 8 and 5 / 8 of the diameter of the cylindrical cyclone chamber 24. Specifically, the bottom end of the overflow pipe 3 is inserted into the cylindrical vortex chamber 24 to a depth of 1 / 2 of the height of the cylindrical vortex chamber 24, and the diameter of the overflow pipe 3 is 1 / 2 of the diameter of the cylindrical vortex chamber 24, which can drive the fluid in the entire flow field to rotate.

[0036] like Figure 1 and Figure 2 As shown, in this embodiment, the overflow diffusion chamber 4 includes a first cylindrical filter screen 41. The bottom end of the first cylindrical filter screen 41 is connected to the overflow pipe 3, and the top end is provided with a circular filter screen 44. The overflow diffusion chamber 4 allows the oil to be sufficiently decelerated within the diffusion chamber, and the filter screen in the overflow diffusion chamber 4 can make the flow rate more stable. The oil-gas mixture flowing out of the overflow pipe 3 enters the overflow diffusion chamber 4 for diffusion treatment. The oil is decelerated by the first cylindrical filter screen 41 and / or the circular filter screen 44, thereby reducing the velocity of the oil flowing out of the overflow diffusion chamber 4. Optionally, the diameter of the first cylindrical filter screen 41 is the same as the diameter of the cylindrical vortex chamber 24.

[0037] like Figure 1 and Figure 2 As shown, in this embodiment, a first support strip 42 is provided on the first cylindrical filter screen 41 to improve the strength of the first cylindrical filter screen 41. Optionally, the first support strip 42 is arranged along the axial direction of the first cylindrical filter screen 41 or along the circumferential direction of the first cylindrical filter screen 41.

[0038] like Figure 1 and Figure 2 As shown, in this embodiment, the circular filter screen 44 is detachably connected to the top of the first cylindrical filter screen 41 via the annular cover plate 43. The structure is simple and the circular filter screen 44 can be quickly disassembled and assembled to facilitate cleaning of the inside of the overflow diffusion chamber 4.

[0039] like Figure 1 and Figure 2As shown in this embodiment, the height of the conical section 5 of the cyclone chamber and the diameter of the underflow port 6 are important factors affecting the separation efficiency of the hydrocyclone. They not only affect the residence time of bubbles in the cyclone chamber, but also the centrifugal force and buoyancy experienced by the oil-gas mixture. Numerical analysis revealed that both excessively large and small heights of the conical section 5 and underflow ports 6 reduce separation efficiency. Therefore, a higher separation efficiency is achieved when the height of the conical section 5 is 3 to 4 times the height of the cylindrical section 2 of the cyclone chamber, and the diameter of the underflow port 6 is 3 / 8 to 5 / 8 times the diameter of the cylindrical cyclone chamber 24. Specifically, the height of the conical section 5 is 3 times the height of the cylindrical section 2 of the cyclone chamber, and the diameter of the underflow port 6 is 1 / 2 the diameter of the cylindrical cyclone chamber 24.

[0040] like Figure 1 and Figure 2 As shown, in this embodiment, the underflow diffusion chamber 7 includes a second cylindrical filter screen 73. The top end of the second cylindrical filter screen 73 is connected to the underflow port 6 via a circular connecting plate 71. The underflow diffusion chamber 7 allows the oil to be sufficiently decelerated within the diffusion chamber, and the filter screen in the underflow diffusion chamber 7 makes the flow velocity more stable. The oil flows into the second cylindrical filter screen 73 from the underflow port 6 and is decelerated by the second cylindrical filter screen 73, thereby preventing the oil flowing out of the underflow port 6 from vertically washing the bottom of the oil tank and avoiding stirring up sediment. Optionally, the diameter of the second cylindrical filter screen 73 is the same as the diameter of the cylindrical vortex chamber 24.

[0041] like Figure 1 and Figure 2 As shown, in this embodiment, the bottom end of the second cylindrical filter screen 73 is connected to a circular base plate 74. The circular base plate 74 does not have through holes to prevent oil from vertically washing the bottom of the oil tank and avoid stirring up the sediment.

[0042] like Figure 1 and Figure 2 As shown, in this embodiment, a second support strip 72 is provided on the second cylindrical filter screen 73 to improve the strength of the second cylindrical filter screen 73. Optionally, the second support strip 72 is arranged along the axial direction of the second cylindrical filter screen 73 or along the circumferential direction of the second cylindrical filter screen 73.

[0043] Figure 1 This is a vector diagram of the axial section velocity of the vortex chamber under low flow conditions (flow rate less than 60 L / min). Figure 2 This is a vector diagram of the axial section velocity of the cyclone chamber under high flow rate conditions (flow rate greater than or equal to 60 L / min). The size of the vector arrows in the diagram represents the magnitude of the velocity, and the direction of the arrows represents the velocity direction; the darker the arrow, the smaller the velocity. For ease of analysis, the arrow sizes at the inlet of both sections are displayed consistently. Figure 1 and Figure 2 It can be seen that the internal flow patterns under low-flow-rate conditions and high-flow-rate conditions are quite different: for example Figure 4As shown, the arrow inside the overflow pipe is larger under low flow conditions than under high flow conditions, indicating that the proportion of oil flowing out of the overflow pipe is larger under low flow conditions, i.e., the flow split ratio is larger. This indicates that the swirling effect is not significant under low flow conditions. Since the entire device is located below the oil tank surface, the bottom flow diffuser chamber, being at the bottom of the tank, has a higher outlet pressure than the overflow diffuser chamber. Most of the oil-gas mixture, after swirling through the cylindrical section 2 of the swirling chamber, directly enters the overflow diffuser chamber from the overflow, then enters the oil tank after filtration and diffusion, finally separating into bubbles at the liquid surface; while... Figure 5 Figure 4 Figure 5 Figure 4 Figure 5 As shown, under high flow rate conditions, the swirling velocity is high, the swirling effect is significant, the flow splitting ratio is small, and the flow rate is low. A portion of the oil with a higher gas content in the central region enters the tank below the liquid surface through the overflow diffusion chamber via filtration and diffusion, while a portion of the oil with a lower gas content in the periphery enters the bottom of the tank from the underflow diffusion chamber under the influence of gravity. Therefore, the flow rate adaptability of this invention is wide.

[0044] A hydraulic system comprising the aforementioned oil-gas cyclone diffusion separation device, capable of efficiently and quickly removing air bubbles from oil.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An oil-gas cyclone diffusion separation device, characterized in that, It includes an overflow diffusion chamber (4), an overflow pipe (3), a cylindrical section of a vortex chamber (2), a conical section of a vortex chamber (5), and a bottom flow diffusion chamber (7) connected sequentially from top to bottom. The top end of the cylindrical section (2) of the vortex chamber is connected to the overflow diffusion chamber (4) through the overflow pipe (3). The cylindrical section (2) of the vortex chamber is connected to the return oil inlet pipe (1). The bottom end of the conical section (5) of the vortex chamber is provided with an underflow port (6) for connecting to the underflow diffusion chamber (7). The cylindrical section (2) of the swirl chamber includes a cylindrical swirl chamber (24). The cylindrical swirl chamber (24) is provided with a lower wall surface (23) of a spiral lower swirl channel and a swirl wall (25) in the shape of an Archimedean spiral. The cylindrical swirl chamber (24), the lower wall surface (23) of the spiral lower swirl channel, and the swirl wall (25) form a spiral lower swirl channel (22). The pre-swirl inlet (21) on the spiral lower swirl channel (22) is connected to the return oil inlet pipe (1). The inner wall surface of the swirl wall (25) is tangent to the inner wall surface of the cylindrical swirl chamber (24). The centerline of the pre-swirl inlet (21) is arranged along the tangential direction of the cylindrical swirl chamber (24). The bottom end of the overflow pipe (3) is inserted into the cylindrical vortex chamber (24), and the depth to which the bottom end of the overflow pipe (3) is inserted into the cylindrical vortex chamber (24) is greater than or equal to 1 / 2 of the height of the cylindrical vortex chamber (24). The diameter of the overflow pipe (3) is greater than or equal to 1 / 2 the diameter of the cylindrical vortex chamber (24). The overflow diffusion chamber (4) includes a first cylindrical filter screen (41), the bottom end of which is connected to the overflow pipe (3), and a circular filter screen (44) is provided at the top end. The underflow diffusion chamber (7) includes a second cylindrical filter screen (73), the top of which is connected to the underflow port (6) via an annular connecting plate (71). One end of the return oil inlet pipe (1) is used to connect to the circular port (11) of the return oil pipe, and the other end is a square port (12) used to connect to the pre-swirling inlet (21). The overflow diffusion chamber (4) is placed below the oil tank liquid level or part of the filter screen of the overflow diffusion chamber (4) is exposed above the oil tank liquid level. The intersection of the lower wall surface (23) of the spiral swirling channel and the cylindrical swirling chamber (24) is a cylindrical helix. The pitch of the cylindrical helix is ​​1.5 to 2.5 times the height of the cylindrical section (2) of the swirling chamber.

2. The oil-gas cyclone diffusion separation device according to claim 1, characterized in that, The first cylindrical filter screen (41) is provided with a first support strip (42).

3. The oil-gas cyclone diffusion separation device according to claim 1, characterized in that, The circular filter screen (44) is detachably connected to the top of the first cylindrical filter screen (41) via a circular cover plate (43).

4. The oil-gas cyclone diffusion separation device according to claim 1, characterized in that, The height of the conical section (5) of the swirl chamber is 3 to 4 times the height of the cylindrical section (2) of the swirl chamber, and the diameter of the underflow port (6) is greater than or equal to 1 / 2 the diameter of the cylindrical swirl chamber (24).

5. The oil-gas cyclone diffusion separation device according to claim 1, characterized in that, The bottom end of the second cylindrical filter (73) is connected to a circular base plate (74), and a second support strip (72) is provided on the second cylindrical filter (73).

6. A hydraulic system, characterized in that... The oil and gas cyclone diffusion separation device includes any one of claims 1 to 5.

Images