Coalescence reinforced cyclone separation device and separation method for removing oil drops from gas

Abstract

The invention relates to a coalescence reinforced cyclone separation device and method for removing oil drops from gas. The device comprises a cylindrical barrel, the interior of the barrel is divided into an inlet cylindrical section provided with a tangential inlet, the lower portion of the inlet cylindrical section is sequentially provided with a first-stage rotational flow section, a second-stage rotational flow section and a bottom oil storage section which are coaxially communicated with one another, and the upper portion of the inlet cylindrical section is provided with a top filtering section coaxially communicated with the inlet cylindrical section; coalescence assemblies are attached to the inner walls of the inlet cylindrical section, the first-stage rotational flow section and the second-stage rotational flow section, a bottom coalescence triangle is arranged in the center of the bottom face of the bottom oil storage section, and a top filtering assembly is coaxially arranged in the top filtering section; the cyclone separation and coalescence separation technologies are combined, centrifugal force and the adhesion effect of coalescence fibers are utilized, fine oil drops are captured and coalesced into large oil drops, the large oil drops finally flow into the bottom oil storage section, gas purification is achieved, and oily liquid drops small in size and wide in particle size range in gas are effectively separated. The device has the advantages of high separation precision, high efficiency, compact structure, convenience in maintenance and the like.

Description

Technical Field

[0001] The invention relates to the technical field of oil-gas separation, and in particular to a coalescence-enhanced cyclone separation device and a separation method for gas de-oiling droplets. Background Art

[0002] The supercritical CO2 turbine power generation system is a small-sized, fast-response, and efficient power generation system with broad application prospects in the fields of electricity, military industry, aerospace, etc. As a closed-loop system working under high temperature, high pressure, and high speed, the supercritical CO2 turbine power generation system has the overall requirements of zero external leakage and no need for air replenishment. The carbon dioxide working fluid in its turbine and compressor will flow to the low-pressure gearbox through the dry gas seal. The leaked carbon dioxide working fluid needs to be recovered and sent back to the main circulation loop. However, since carbon dioxide enters the low-pressure gearbox, it will mix with the volatile lubricating oil gas, and the loop system cannot accept lubricating oil particles in the carbon dioxide gas flow. Therefore, oil and gas separation is required before carbon dioxide is re-injected into the main circulation loop. The technical difficulty in achieving the above goals is that the lubricating oil particles in carbon dioxide have the characteristics of small scale and wide particle size range. The traditional oil and gas separation method is difficult to meet the purification requirements of carbon dioxide and it is difficult to ensure the safe operation of the main circulation loop.

[0003] Cyclone separation is a field separation method that uses the centrifugal force of the cyclone generated by high-speed rotation to separate the two phases based on the density difference between the two phases. It belongs to the physical separation technology in the field of oil and gas separation and is often used to separate fine oil droplets. It has a series of advantages such as large processing capacity, compact structure, and easy operation. The cyclone is a high-efficiency unit equipment that uses cyclone separation technology to achieve separation of two-phase systems. However, due to the constraints of turbulent diffusion and the influence of fluid phase differences, conventional cyclones can only process oil droplets with a particle size of more than 10μm. In actual industrial applications, it is often coupled with other oil and gas separation technologies to achieve high-precision oil and gas separation.

[0004] Coalescence separation uses coalescence fibers as a medium to make fine dispersed phase oil droplets coalesce and grow by adhering to the surface of the medium, thereby realizing the rapid separation of fine oil droplets in the gas-liquid system. It has a series of advantages such as continuous operation, high efficiency, small size, simple maintenance, and self-cleaning. Coalescence fibers can capture fine oil droplets in the gas and merge small droplets into large droplets. The essential process of fiber coalescence separation is to capture, coalesce and grow fine oil droplets through the wetting coalescence of the material surface and the collision coalescence process in the microchannel. The surface of the fiber material is not only the medium for the fine oil droplets to coalesce and grow after being captured, but also the bridge for the droplets to be transported and transferred in the fiber after coalescence. Under the action of the continuous phase's drag force, its own gravity and other forces, the large oil droplets after coalescence undergo deformation and transfer (transfer between fibers) until they fall off the fiber surface, completing the separation of the two phases. In addition, the coalescing fibers can effectively reduce the splashing and rebound of oil droplets and the wall in the cyclone inlet area and annular channel, reduce the fine oil droplets formed by the movement and breakup of oil droplets, and enhance the coalescence and capture effect of the wall liquid film on droplets. Therefore, the fiber coalescence separation technology has great potential in the field of high-precision gas purification to achieve fine oil droplet separation.

[0005] A Chinese invention patent (CN111156089A) discloses a pre-gas-liquid separator and method for a gas turbine air filtration system. This invention reduces liquid particles in the gas before entering the air filtration system through cyclone separation of multi-stage volutes, conical cylinders, guide vanes, and a one-way metal filter, thereby extending the service life of the filtration system and reducing the operation and maintenance cost of the filtration system. However, the separation accuracy of the device is low and it cannot achieve the separation of micro-sized lubricating oil particles in the carbon dioxide working medium.

[0006] A Chinese invention patent (CN116020222A) discloses a combined coalescing cyclone separator for natural gas purification, and a Chinese utility model patent (CN215842291U) authorizes a high-precision gas-liquid separator. Both patents use a combination of cyclone tubes, coalescing cores and other separation methods to achieve high-precision separation of droplets with smaller particle sizes. However, both devices are simple series superpositions of different separation technologies, resulting in large equipment sizes and high production costs.

[0007] The Chinese invention patent (CN115212668) discloses a coalescing filter element and a coalescing filter. This invention allows the gas to enter the supporting inner frame after being filtered by the filter element from the outside of the coalescing filter element, so that the gas is filtered by the filter element, thereby filtering out the particulate components in the gas, thereby achieving the purpose of purifying the gas. This invention improves the separation accuracy of the coalescing filter element and avoids the secondary entrainment phenomenon of the coalescing filter element. However, in the face of lubricating oil particles with a wide particle size range, the possible large particle size oil droplets will greatly shorten the life of the coalescing filter element in the coalescing filter, and it is not convenient to operate and maintain. Summary of the invention

[0008] The purpose of the present invention is to provide a new type of agglomeration-enhanced cyclone separation device and method for gas de-oiling to address the problems of low separation accuracy, large footprint, low separation efficiency, serious oil droplet entrainment, and difficult operation and maintenance in the existing oil-gas separation device system. The device has the advantages of high separation accuracy, compact structure, high separation efficiency, easy maintenance, no need for additional power input, and no addition of any chemical reagents.

[0009] Invention ideas

[0010] The idea of ​​the present invention is to achieve efficient and high-precision oil-gas separation for gases containing small-sized, lubricating oil particles with a wide particle size range through multi-dimensional coupling of cyclone separation technology and coalescence separation technology. The specific ideas are as follows:

[0011] 1. The gas containing oil droplets enters the inlet cylindrical section from the tangential inlet. The cylindrical structure and the spiral blades of the cylindrical section force the gas-liquid two-phase fluid to produce strong rotational motion. Due to the differences in size and density, the gas-liquid two-phase has different dynamic characteristics under the coupling of the cyclone field and the gravity field. In the inlet area and the annular area, the oil droplets are thrown to the wall of the device, and rebound, splash, break, gather and capture with the oil film on the wall. Among them, the secondary small oil droplets produced by the splash and break of the oil droplets will further reduce the average particle size of the oil droplets and increase the difficulty of high-precision separation of oil and gas. Therefore, it is necessary to avoid the rebound and splash of the oil droplets to increase the probability of the oil droplets being gathered and captured by the oil film on the wall. The cylindrical section coalescing component on the inner wall of the inlet cylindrical section enhances the wettability and surface tension of the wall through the structure and specific materials of sparse coalescing fibers on the surface, dense coalescing fibers in the middle, and circumferential hollow guiding fibers on the bottom layer. The microchannels on the surface of the coalescing fiber can promote the coalescence and growth of oil droplets, increasing the probability of droplets being coalesced and captured by the wall oil film. The flexibility of the coalescing material and the larger surface tension within the coalescing component further avoid the rebound, splashing and breakage of oil droplets, strengthen the cyclone separation of the device, and achieve coarse separation of oil and gas.

[0012] 2. The inverted cone structure of the primary and secondary cyclone sections further forces the gas to rotate faster, further enhancing the centrifugal force of the oil droplets, so that the oil droplets with smaller particle sizes move to the surface of the coalescing components of the primary and secondary cyclone sections and are captured by the oil film on the surface of the coalescing components. The coalescing components here are sparse coalescing fibers on the surface, dense coalescing fibers in the middle, and radial hollow guiding fibers at the bottom. After the fine oil droplets gather and grow on the surface of the coalescing fibers and in the microchannels, they undergo deformation, transfer, and transmission between fibers under the action of the continuous phase fluid drag and their own gravity, and move from sparse coalescing fibers and dense coalescing fibers to radial hollow guiding fibers, and enter the bottom oil storage section along the wall of the device through the bottom flow port, realizing the separation of small oil droplets.

[0013] 3. The airflow moves upward through the overflow pipe to the top filter section with the internal vortex flow, and is evenly dispersed on the surface of the pre-filter layer of the top filter component under the action of the top gas distributor. Under the driving force of the gas, the gas passes through the coalescing filter layer formed by rolling multiple layers of coalescing fibers, and is finally purified and discharged through the purified gas outlet. Very few fine oil droplets gather and grow between the coalescing fibers in the coalescing filter layer. When the size exceeds the critical sliding size, they are discharged to the oil guide groove through the drainage layer, and flow to the first-stage vortex section positioning contact groove under the action of the oil guide groove, and flow to the bottom oil storage section through the guiding fibers at the bottom of the coalescing components of the first and second vortex sections.

[0014] 4. The bottom coalescing triangle of the bottom oil storage section can enhance the internal swirl of the gas and effectively mix the lubricating oil at the bottom of the wall. The stored lubricating oil is discharged and recovered through the oil discharge port after the device has been running for a certain period of time.

[0015] In summary, the coalescence-enhanced cyclone separation device and method for gas deoiling droplets of the present invention can achieve high-precision separation of oily particles of small scale and wide particle size range in the gas.

[0016] The present invention is achieved through the following technical solutions:

[0017] A coalescence-enhanced cyclone separation device for gas de-oiling, characterized in that the separation device comprises: a cylindrical barrel, the barrel is divided into an inlet cylindrical section with a tangential inlet, the lower part of the inlet cylindrical section is a primary cyclone section, a secondary cyclone section and a bottom oil storage section which are coaxially connected to each other, the upper part of the inlet cylindrical section is a top filter section which is coaxially connected to the inlet cylindrical section, the inner walls of the inlet cylindrical section, the primary cyclone section and the secondary cyclone section are respectively attached with a cylindrical section coalescence component, a primary cyclone section coalescence component and a secondary cyclone section coalescence component, a bottom coalescence triangle is provided at the center of the bottom surface of the bottom oil storage section, and the top filter component is coaxially arranged in the top filter section;

[0018] The top filter section has a purified gas outlet at the top and an oil guide groove at the bottom. A conical top gas distributor filled with circular holes is provided in the top filter assembly.

[0019] An overflow pipe connected up and down and a cylindrical spiral blade located between the inlet cylindrical section barrel and the overflow pipe are arranged at the axis of the inlet cylindrical section. The overflow pipe has an overflow pipe spiral blade. An oil guide groove is also arranged in the inner wall of the inlet cylindrical section barrel. The upper and lower ends of the oil guide groove are respectively connected to the oil guide groove and the first-stage swirl section positioning contact groove.

[0020] The first-stage cyclone section coalescing assembly and the second-stage cyclone section coalescing assembly are attached to the inner wall of the cylinder through the first-stage cyclone section positioning contact groove and the second-stage cyclone section positioning contact groove respectively and gradually thicken, so that the first-stage cyclone section and the second-stage cyclone section become a gradually shrinking inverted cone structure, and are connected with the bottom oil storage section through the bottom flow port;

[0021] An oil discharge port is arranged at the lower part of the bottom oil storage section, and the bottom coalescing triangle in the center extends to the bottom of the secondary cyclone section through the bottom flow port.

[0022] The aspect ratio L1 / D1 of the inlet cylindrical section is 2-5, the overflow pipe diameter D4 is 1 / 4-1 / 3 of the cylindrical section diameter D1, the interval N1 between adjacent cylindrical section spiral blades is 1 / 10-1 / 4 of the cylindrical section length L1, the interval N2 between adjacent overflow pipe spiral blades is 1 / 10-1 / 5 of the cylindrical section length L1, the overflow pipe length L11 is 1 / 2-3 / 4 of the cylindrical section length L1, the oil guide groove diameter D11 is 1 / 200-1 / 100 of the cylindrical section diameter D1, and the number is 2-6.

[0023] The diameter D2 of the primary cyclone section is 1 / 2-3 / 4 of the diameter D1 of the cylindrical section, and the cone angle a1 is 40-80°. The diameter D3 of the secondary cyclone section is 1 / 6-1 / 2 of the diameter D1 of the cylindrical section, and the cone angle a1 is 10-30°. The thickness t2 of the coalescing component of the primary cyclone section is equal to the thickness t3 of the coalescing component of the secondary cyclone section.

[0024] The aspect ratio L2 / D5 of the top filtering section is 1-3, and the opening rate Φ of the top gas distributor is 30-70%.

[0025] The cylindrical section coalescing component consists of three layers: sparse coalescing fibers on the surface, dense coalescing fibers in the middle, and circumferential hollow guiding fibers at the bottom; the first-level cyclone section coalescing component and the second-level cyclone section coalescing component consist of three layers: sparse coalescing fibers on the surface, dense coalescing fibers in the middle, and radial hollow guiding fibers at the bottom; the bottom coalescing triangle is rolled up with three layers of sparse coalescing fibers, dense coalescing fibers, and radial hollow guiding fibers; wherein the sparse coalescing fibers are coalescing fibers with a porosity greater than or equal to 50%, the dense coalescing fibers are coalescing fibers with a porosity less than 50%, the circumferential hollow guiding fibers are coalescing fibers with a hollow duct structure consistent with the circumferential direction of the device, and the radial hollow guiding fibers are coalescing fibers with a hollow duct structure consistent with the axial direction of the device.

[0026] The top filter component is composed of a pre-filter layer, a coalesced filter layer, and a drainage layer formed by rolling coalesced fibers, wherein the pre-filter layer is made of a ring-shaped arrangement of coalesced fibers with a porosity of less than 50%, the coalesced filter layer is made of a spirally staggered arrangement of coalesced fibers with a porosity of less than 40%, and the drainage layer is made of a ring-shaped arrangement of coalesced fibers with a porosity of less than 30%.

[0027] The agglomerated fibers are preferably one or more of polytetrafluoroethylene, polyacrylonitrile, and glass fibers.

[0028] The present invention also provides a method for coalescence-enhanced cyclone separation of gas deoiled droplets, characterized in that the method comprises the following steps:

[0029] a1. The gas containing oil droplets enters the inlet cylindrical section from the tangential inlet, and generates high-speed rotation under the action of the cylindrical section swirl blades. The oil droplets in the gas are thrown to the surface of the cylindrical section coalescing component under the action of centrifugal force, and flow along the circumferential hollow guiding fibers through the wall surface of the first-stage swirl section positioning contact groove and the wall surface of the second-stage swirl section positioning contact groove to the bottom oil storage section;

[0030] a2. The gas separated by the initial cyclone enters the primary cyclone section and the secondary cyclone section and is further accelerated. Under the centrifugal force generated by the further high-speed rotation, the oil droplets with smaller particle sizes are thrown to the surface of the coalescing components of the primary and secondary cyclone sections and captured by the coalescing fibers. They are transported by radial hollow guiding fibers through the positioning contact groove of the secondary cyclone section and the bottom flow port and discharged to the bottom oil storage section;

[0031] a3. When the gas separated by the second cyclone flows to the bottom flow port, the gas migrates to the negative pressure zone in the center area of ​​the separation device under the support of the bottom coalescing triangle, and moves upward through the overflow pipe to the top filter section with the inner cyclone. The coalescing triangle can effectively prevent the lubricating oil in the bottom oil storage section from mixing back and affecting the oil-gas separation effect;

[0032] a4. The gas entering the top filter section from the overflow pipe is further accelerated by the spiral blades of the overflow pipe and evenly distributed on the surface of the pre-filter layer of the top filter component through the top gas distributor. Under the driving force of the gas, the multi-layered coalescing filter layer filters the gas containing fine oil droplets. The coalesced fine oil droplets are discharged to the bottom oil storage section through the drainage layer, oil guide groove, oil guide groove, first-level cyclone section positioning contact groove, second-level cyclone section positioning contact groove, and along the guiding fibers on the wall. The purified gas enters the purified gas outlet and is discharged.

[0033] Beneficial Effects

[0034] The present invention uses organic coupling coalescence separation technology and cyclone separation technology to utilize the cyclone fluid motion characteristics, the collision, crushing and coalescence characteristics of oil droplets, and the capture, transportation and separation characteristics of coalescence fibers in a limited space to achieve efficient and deep separation of lubricating oil particles with small scale and wide particle size range in the gas. The device of this invention has high separation accuracy, high separation efficiency, compact structure, convenient maintenance, no need for additional power input devices, and no addition of any chemical reagents. It can add multiple cyclone sections to enhance separation accuracy and can be directly installed before the main circulation loop to achieve gas purification. Compared with the prior art, it greatly reduces the size of the equipment, improves the separation accuracy, extends the life of the device, ensures the safety of the main circulation loop, and has considerable economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention. They only constitute a part of this specification to further explain the present invention, and do not constitute a limitation of the present invention.

[0036] In the drawings, various parts are not necessarily drawn according to actual scale.

[0037] Figure 1 It is a schematic diagram of the principle of the device of the present invention.

[0038] Figure 2 It is a schematic diagram of the principle of enhanced cyclone separation of the coalescence component of the device of the present invention.

[0039] Figure 3 It is a half-section assembly diagram of the device of the present invention.

[0040] Figure 4 It is a schematic diagram of the three-dimensional structure of the device of the present invention.

[0041] Figure 5 Schematic diagram of the structural dimensions of the device of the present invention.

[0042] Fig. 6(a) is a schematic diagram of the cross-sectional structure of the inlet cylindrical section and the cylindrical section coalescing assembly of the device of the present invention, and Fig. 6(b) is a schematic diagram of the structural dimensions of the inlet cylindrical section and the cylindrical section coalescing assembly of the device of the present invention.

[0043] Figure 7(a) is a schematic diagram of the cross-sectional structure of the primary cyclone section, secondary cyclone section, primary cyclone section coalescing assembly and secondary cyclone section coalescing assembly of the device of the present invention. Figure 7(b) is a schematic diagram of the structural dimensions of the primary cyclone section, secondary cyclone section, primary cyclone section coalescing assembly and secondary cyclone section coalescing assembly of the device of the present invention.

[0044] Fig. 8(a) is a schematic diagram of the cross-sectional structure of the bottom oil storage section and the bottom agglomeration triangle of the device of the present invention, and Fig. 8(b) is a schematic diagram of the dimensions of the bottom oil storage section and the bottom agglomeration triangle of the device of the present invention.

[0045] Fig. 9(a) is a schematic diagram of the cross-sectional structure of the top filtration section and the top membrane assembly of the device of the present invention, and Fig. 9(b) is a schematic diagram of the structural dimensions of the top filtration section and the top membrane assembly of the device of the present invention.

[0046] FIG. 10( a ) is a schematic diagram of the three-dimensional structure of the top filter assembly of the device of the present invention, and FIG. 10( b ) is a schematic diagram of the cross-section of the top filter assembly of the device of the present invention.

[0047] FIG. 11( a ) is a schematic diagram of the ring-shaped arrangement of coalesced fibers in the pre-filtration layer and the drainage layer of the device of the present invention, and FIG. 11( b ) is a schematic diagram of the spiral staggered arrangement of coalesced fibers in the coalesced filtration layer of the device of the present invention.

[0048] Among them, the figure marks represent the following components and devices respectively, 1: inlet cylindrical section, 2: primary cyclone section, 3: secondary cyclone section, 4: bottom oil storage section, 5: top filter section, 6: cylindrical section coalescing assembly, 7: primary cyclone section coalescing assembly, 8: secondary cyclone section coalescing assembly, 9: bottom coalescing triangle, 10: top filter assembly, 11: tangential inlet, 12: cylindrical section spiral blade, 13: overflow pipe, 14: overflow pipe spiral blade, 15: oil guide groove, 21: primary cyclone section positioning contact groove, 22: secondary cyclone section positioning contact groove, 41: bottom flow port, 42: oil discharge port, 51 top gas distributor, 52 oil guide groove, 53: purified gas outlet, 101: pre-filtration layer, 102 coalescing filtration layer, 103 liquid drainage layer. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the accompanying drawings and specific examples. However, it should be understood that these examples are only used to illustrate the present invention and do not constitute a limitation of the scope of the present invention. The test methods in the following examples that do not specify specific conditions are usually based on conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all percentages and parts are by weight.

[0050] Embodiment 1:

[0051] In the laboratory, an ultrasonic smoke generator was used to replace the lubricating oil with deionized water to simulate the oil-containing gas to be purified and the gas was treated with the device of the present invention. The total gas flow rate was 10m 3 / h, the deionized water flow rate was set from 0 to 10 ml / min, and one group of experiments was conducted with every 2 ml / min. The coalescing fiber used in the coalescing component was preferably polytetrafluoroethylene fiber.

[0052] Design parameters: Assemble the device of the present invention as shown in the figure, wherein the inlet cylindrical section aspect ratio L1 / D1 is 3, the overflow pipe diameter D4 is 1 / 4 of the cylindrical section diameter D1, the interval N1 between adjacent cylindrical sections of spiral blades is 1 / 6 of the cylindrical section length L1, the interval N2 between adjacent overflow pipe spiral blades is 1 / 6 of the cylindrical section length L1, the overflow pipe length L11 is 1 / 2 of the cylindrical section length L1, and the oil guide groove diameter D11 is 1 / 2 of the cylindrical section diameter D1 00, the number is 4, the diameter D2 of the first-stage cyclone section is 1 / 2 of the diameter D1 of the cylindrical section, the cone angle a1 is 40°, the diameter D3 of the second-stage cyclone section is 1 / 6 of the diameter D1 of the cylindrical section, the cone angle a1 is 20°, the thickness t1 of the cylindrical section coalescing assembly, the thickness t2 of the first-stage cyclone section coalescing assembly and the thickness t3 of the second-stage cyclone section coalescing assembly are equal, the aspect ratio L2 / D5 of the top filter section is 2, and the porosity Φ of the top gas distributor is 50%.

[0053] Application effect: After being treated by the device described in the present invention, the gas-liquid separation efficiency of each group of experiments is higher than 99.9%, and the water content of the gas after final purification is less than 0.1mg / m 3 .

[0054] Embodiment 2:

[0055] In the laboratory, a scaled-up experiment was conducted, using a fume generator to simulate the gas containing lubricating oil particles and using the device of the present invention to treat the gas. The total gas flow rate was 40m 3 / h, the oil inlet flow rate of the fume generator is set from 0 to 5ml / min, and a group of experiments is set every 1ml / min. The smoke temperature of the fume generator is set from 150 to 300℃, and a group of experiments is set every 50℃. The agglomeration fiber used in the agglomeration component is a mixture of stainless steel wire and preferred polytetrafluoroethylene fiber. The oil content in the gas is measured by an aerosol photometer.

[0056] Design parameters: Assemble the device of the present invention as shown in the figure, wherein the inlet cylindrical section aspect ratio L1 / D1 is 4, the overflow pipe diameter D4 is 1 / 4 of the cylindrical section diameter D1, the interval N1 between adjacent cylindrical sections of spiral blades is 1 / 8 of the cylindrical section length L1, the interval N2 between adjacent overflow pipe spiral blades is 1 / 6 of the cylindrical section length L1, the overflow pipe length L11 is 3 / 4 of the cylindrical section length L1, and the oil guide groove diameter D11 is 1 / 2 of the cylindrical section diameter D1 00, the number is 4, the diameter D2 of the first-stage cyclone section is 1 / 2 of the diameter D1 of the cylindrical section, the cone angle a1 is 40°, the diameter D3 of the second-stage cyclone section is 1 / 6 of the diameter D1 of the cylindrical section, the cone angle a1 is 10°, the thickness t1 of the cylindrical section coalescing assembly, the thickness t2 of the first-stage cyclone section coalescing assembly and the thickness t3 of the second-stage cyclone section coalescing assembly are equal, the aspect ratio L2 / D5 of the top filter section is 1, and the porosity Φ of the top gas distributor is 40%.

[0057] Application effect: After being treated by the device of the present invention, the oil-gas separation efficiency of each group of experiments is higher than 99.8%, and the mass concentration of lubricating oil in the gas after final purification is less than 0.2mg / m 3 .

[0058] Embodiment 3:

[0059] In order to simulate the actual situation, a pilot test device was built, and a fume generator and compressed air were used to simulate the gas containing lubricating oil particles. The gas was treated by the device of the present invention. The total oil and gas flow rate was set to 72m 3 / h、90m 3 / h、126m 3 / h three gradients, the outlet pressure is 0.1Mpa, the pipeline temperature is controlled at 50-60℃, the oil inlet flow rate of the fume generator is set to 1ml / min, 2ml / min, and 3ml / min three gradients, the smoke temperature of the fume generator is controlled at 300℃ for the experiment, the agglomeration fiber used in the agglomeration component is a mixture of stainless steel wire, glass fiber and polytetrafluoroethylene fiber, an aerosol photometer is used to measure the oil content in the gas, and a laser dust particle technology is used to count oil droplets of different particle sizes.

[0060] Design parameters: Assemble the device of the present invention as shown in the figure, wherein the aspect ratio of the inlet cylindrical section L1 / D1 is 4, the overflow pipe diameter D4 is 1 / 4 of the cylindrical section diameter D1, the interval N1 of the spiral blades of adjacent cylindrical sections is 1 / 10 of the cylindrical section length L1, the interval N2 of the spiral blades of adjacent overflow pipes is 1 / 10 of the cylindrical section length L1, the overflow pipe length L11 is 3 / 4 of the cylindrical section length L1, and the oil guide groove diameter D11 is 1 / 200, the number is 6, the diameter D2 of the first-stage cyclone section is 1 / 2 of the diameter D1 of the cylindrical section, the cone angle a1 is 40°, the diameter D3 of the second-stage cyclone section is 1 / 6 of the diameter D1 of the cylindrical section, the cone angle a1 is 10°, the thickness t1 of the cylindrical section coalescing assembly, the thickness t2 of the first-stage cyclone section coalescing assembly and the thickness t3 of the second-stage cyclone section coalescing assembly are equal, the aspect ratio L2 / D5 of the top filter section is 1, and the porosity Φ of the top gas distributor is 40%.

[0061] Application effect: After being treated by the device described in the present invention, the pressure drop of the device under each group of gas flow is shown in Table 1.

[0062] Table 1 Pressure drop of the device at different gas flow rates

[0063]

[0064] When the device is at a smoke temperature of 308°C and the oil inlet volume is 2ml / min, the oil-gas separation performance at different airflow rates is shown in Table 2. The oil-gas separation efficiency of each group of experiments is higher than 99.9%, and the final lubricating oil mass concentration of the purified gas is less than 0.1mg / m 3 .

[0065] Table 2 Oil-gas separation performance of the device at different gas flow rates

[0066]

[0067] The device is at a fume temperature of 308°C and an oil and gas flow rate of 126m 3 / h, the oil-gas separation performance under different oil inlet rates is shown in Table 3. The oil-gas separation efficiency of each group of experiments is higher than 99.9%, and the final lubricating oil mass concentration of the purified gas is less than 0.1 mg / m 3 .

[0068] Table 3 Oil-gas separation performance of the device at different oil inlet rates

[0069]

[0070] In order to further investigate the separation performance of the device for fine oil droplets, a laser dust particle counter was used to measure the particle size distribution of the inlet and outlet oil droplets, and the separation of the device for small-size oil droplets was studied. 3 / h, the number of oil droplets with different particle sizes at the device inlet and the device purified gas outlet was tested, and the results are shown in Table 4.

[0071] Table 4 The number of oil droplets of different particle sizes at the inlet and outlet of the device

[0072]

[0073]

[0074] It can be seen from Table 4 that, compared with conventional cyclones that can only process oil droplets with a particle size of more than 10 μm, the device of the present invention has a very good separation effect on oil droplets with a particle size greater than 1 μm, and the separation efficiency of oil droplets with a particle size less than 0.3 μm can also reach 98%.

Claims

1. A coalescence-enhanced cyclone separation device for gas deoiling droplets, characterized in that: The separation device comprises: a cylindrical barrel, which is divided into an inlet cylindrical section with a tangential inlet, the lower part of the inlet cylindrical section is sequentially a primary cyclone section, a secondary cyclone section and a bottom oil storage section which are coaxially connected to each other, the upper part of the inlet cylindrical section is a top filter section which is coaxially connected to the inlet cylindrical section, the inner walls of the inlet cylindrical section, the primary cyclone section and the secondary cyclone section are respectively attached with a cylindrical section coalescing component, a primary cyclone section coalescing component and a secondary cyclone section coalescing component, a bottom coalescing triangle is provided at the center of the bottom surface of the bottom oil storage section, and the top filter assembly is coaxially arranged in the top filter section; The top filter section has a purified gas outlet at the top and an oil guide groove at the bottom. A conical top gas distributor filled with circular holes is provided in the top filter assembly. An overflow pipe connected up and down and a cylindrical spiral blade located between the inlet cylindrical section barrel and the overflow pipe are arranged at the axis of the inlet cylindrical section. The overflow pipe has an overflow pipe spiral blade. An oil guide groove is also arranged in the inner wall of the inlet cylindrical section barrel. The upper and lower ends of the oil guide groove are respectively connected to the oil guide groove and the first-stage swirl section positioning contact groove. The first-stage cyclone section coalescing assembly and the second-stage cyclone section coalescing assembly are attached to the inner wall of the cylinder through the first-stage cyclone section positioning contact groove and the second-stage cyclone section positioning contact groove respectively and gradually thicken, so that the first-stage cyclone section and the second-stage cyclone section become a gradually shrinking inverted cone structure, and are connected with the bottom oil storage section through the bottom flow port; An oil discharge port is arranged at the lower part of the bottom oil storage section, and the bottom coalescing triangle in the center extends to the bottom of the secondary cyclone section through the bottom flow port.

2. The coalescence-enhanced cyclone separation device according to claim 1, characterized in that: The aspect ratio L1 / D1 of the inlet cylindrical section is 2-5, the overflow pipe diameter D4 is 1 / 4-1 / 3 of the cylindrical section diameter D1, the interval N1 between adjacent cylindrical section spiral blades is 1 / 10-1 / 4 of the cylindrical section length L1, the interval N2 between adjacent overflow pipe spiral blades is 1 / 10-1 / 5 of the cylindrical section length L1, the overflow pipe length L11 is 1 / 2-3 / 4 of the cylindrical section length L1, the oil guide groove diameter D11 is 1 / 200-1 / 100 of the cylindrical section diameter D1, and the number is 2-6.

3. The coalescence-enhanced cyclone separation device according to claim 1, characterized in that: The diameter D2 of the primary cyclone section is 1 / 2-3 / 4 of the diameter D1 of the cylindrical section, and the cone angle a1 is 40-80°. The diameter D3 of the secondary cyclone section is 1 / 6-1 / 2 of the diameter D1 of the cylindrical section, and the cone angle a1 is 10-30°. The thickness t2 of the coalescing component of the primary cyclone section is equal to the thickness t3 of the coalescing component of the secondary cyclone section.

4. The coalescence-enhanced cyclone separation device according to claim 1, characterized in that: The aspect ratio L2 / D5 of the top filtering section is 1-3, and the opening rate Φ of the top gas distributor is 30-70%.

5. The coalescence-enhanced cyclone separation device according to claim 1, characterized in that: The cylindrical section coalescing component consists of three layers: sparse coalescing fibers on the surface, dense coalescing fibers in the middle, and circumferential hollow guiding fibers at the bottom; the first-level cyclone section coalescing component and the second-level cyclone section coalescing component consist of three layers: sparse coalescing fibers on the surface, dense coalescing fibers in the middle, and radial hollow guiding fibers at the bottom; the bottom coalescing triangle is rolled up with three layers of sparse coalescing fibers, dense coalescing fibers, and radial hollow guiding fibers; wherein the sparse coalescing fibers are coalescing fibers with a porosity greater than or equal to 50%, the dense coalescing fibers are coalescing fibers with a porosity less than 50%, the circumferential hollow guiding fibers are coalescing fibers with a hollow duct structure consistent with the circumferential direction of the device, and the radial hollow guiding fibers are coalescing fibers with a hollow duct structure consistent with the axial direction of the device.

6. The coalescence-enhanced cyclone separation device according to claim 1, characterized in that: The top filter component is composed of a pre-filter layer, a coalesced filter layer, and a drainage layer formed by rolling coalesced fibers, wherein the pre-filter layer is made of a ring-shaped arrangement of coalesced fibers with a porosity of less than 50%, the coalesced filter layer is made of a spirally staggered arrangement of coalesced fibers with a porosity of less than 40%, and the drainage layer is made of a ring-shaped arrangement of coalesced fibers with a porosity of less than 30%.

7. The coalescence-enhanced cyclone separation device according to claim 5 or 6, characterized in that: The agglomerated fibers are one or more selected from polytetrafluoroethylene, polyacrylonitrile, and glass fibers.

8. A method for coalescence-enhanced cyclone separation of gas deoiled droplets, characterized in that: The method comprises the following steps: a1. The gas containing oil droplets enters the inlet cylindrical section from the tangential inlet, and generates high-speed rotation under the action of the cylindrical section swirl blades. The oil droplets in the gas are thrown to the surface of the cylindrical section coalescing component under the action of centrifugal force, and flow along the circumferential hollow guiding fibers through the wall surface of the first-stage swirl section positioning contact groove and the wall surface of the second-stage swirl section positioning contact groove to the bottom oil storage section; a2. The gas separated by the initial cyclone enters the primary cyclone section and the secondary cyclone section and is further accelerated. Under the centrifugal force generated by the further high-speed rotation, the oil droplets with smaller particle sizes are thrown to the surface of the coalescing components of the primary and secondary cyclone sections and captured by the coalescing fibers. They are transported by radial hollow guiding fibers through the positioning contact groove of the secondary cyclone section and the bottom flow port and discharged to the bottom oil storage section; a3. When the gas separated by the second cyclone flows to the bottom flow port, the gas migrates to the negative pressure zone in the center area of ​​the separation device under the support of the bottom coalescing triangle, and moves upward through the overflow pipe to the top filter section with the inner cyclone. The coalescing triangle can effectively prevent the lubricating oil in the bottom oil storage section from mixing back and affecting the oil-gas separation effect; a4. The gas entering the top filter section from the overflow pipe is further accelerated by the spiral blades of the overflow pipe and evenly distributed on the surface of the pre-filter layer of the top filter component through the top gas distributor. Under the driving force of the gas, the multi-layered coalescing filter layer filters the gas containing fine oil droplets. The coalesced fine oil droplets are discharged to the bottom oil storage section through the drainage layer, oil guide groove, oil guide groove, first-level cyclone section positioning contact groove, second-level cyclone section positioning contact groove, and along the guiding fibers on the wall. The purified gas enters the purified gas outlet and is discharged.

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