A mixing device and method for trace liquids

Abstract

A mixing device and method for trace liquids, which relate to the field of petrochemical engineering. In the present invention, a shunt pipeline is led out from the outlet pipeline of a delivery pump (2), and a part of the crude oil led out from the shunt pipeline is mixed with a demulsifier (3) to reduce the mixing ratio of the demulsifier and the crude oil volume and enhance the mixing effect. A pump outlet regulating valve (9) is provided on the pipeline downstream of the shunt pipeline, and a reflux regulating valve (8) is provided on the shunt pipeline, so that a part of the crude oil flows back from the shunt pipeline to the inlet of the delivery pump. The demulsifier is incorporated into the part of the crude oil flowing back in the shunt pipeline, and then enters a branch mixer (7) provided on the shunt pipeline, and then enters an electric desalting tank (6) for oil-water separation, etc. The present invention has the characteristics of simplicity, good mixing effect, etc., and is suitable for wide promotion and application.

Description

Technical Field

[0001] The present invention relates to the field of petrochemical engineering, and particularly to a mixing device and method for trace liquids. Background Art

[0002] It is known that in the crude oil extracted from nature, in addition to the effective components, there are also a large amount of water and various types of salt substances. The distribution forms of these salt substances are mainly divided into two types. The first type is distributed in the crude oil in a solid state, and the second type exists in the liquid water in the form of water-in-oil. Therefore, after the extracted crude oil enters the refining device, the first step is to desalt and dehydrate it, that is, electro-de-salting. The main process of electro-de-salting is to first mix the crude oil with a demulsifier, and then enter the electro-de-salting tank. The role of the demulsifier is to destroy the water-in-oil distribution form, promote the separation and precipitation of water, and achieve the effect of electro-de-salting. In the existing electro-de-salting process flow, the injection method of the demulsifier is direct injection into the pipeline, and then mixed through a mixer, specifically as Figure 1 shown. After the crude oil is pumped out from the crude oil tank 1 by the transfer pump 2 through the pipeline 4, it is mixed with a certain proportion of the demulsifier 3 into the same pipeline, and then enters the mixer 5 to mix the crude oil and the demulsifier 3, and then enters the electro-de-salting tank 6 for oil-water separation.

[0003] However, in the existing electro-de-salting process flow, the injection amount of the demulsifier 3 is very small, generally in the order of 10 mg / kg, that is, the ratio of the injection amount of the demulsifier 3 to the amount of the crude oil to be mixed is 1:100000. Relative to the amount of the crude oil to be mixed, the injection amount of the demulsifier 3 is very small. Coupled with the direct mixing method of oil and the agent, it further makes the demulsifier 3 unable to be fully dispersed and cannot be fully mixed with the crude oil. Although there is a mixer 5 subsequently, the general conventional mixer 5 has extremely poor mixing effect on multiple streams of materials with large differences in mixing ratios. At the same time, due to the limitations of the device operating conditions, it is not allowed for the mixer 5 to have a large pressure drop, and the pressure drop is a necessary condition to ensure the mixing effect. Therefore, in the existing electro-de-salting process flow, due to the extremely poor mixing effect of the demulsifier 3, the use effect of the demulsifier 3 is severely affected, resulting in the desalting rate of the subsequent electro-de-salting tank 6 not being effectively guaranteed. The desalting rate of the electro-de-salting system in the existing electro-de-salting process flow is around 90%, and it cannot be further improved. Therefore, it is necessary to provide a mixing device and method for trace liquids that can improve the mixing effect of the demulsifier 3 and the crude oil and improve the desalting rate of the electro-de-salting system. Summary of the Invention

[0004] To overcome the deficiencies in the background art, the present invention provides a mixing device and method for trace liquids. In the present invention, a branch is led out from the outlet of the transfer pump for the crude oil to be mixed, and a part of the crude oil led out from the branch is mixed with a demulsifier to reduce the mixing ratio of the demulsifier to the crude oil volume and enhance the mixing effect. Then, after the first mixing of a part of the crude oil and the demulsifier, it is mixed with the crude oil for the second time, and then enters an electro-desalting tank through a mixer for oil-water separation, etc.

[0005] To achieve the above-mentioned invention purpose, the present invention adopts the following technical solutions:

[0006] A mixing device for trace liquids, comprising a crude oil tank, a transfer pump, a mixer, an electro-desalting tank, a branch mixer, a reflux regulating valve and a pump outlet regulating valve. The crude oil tank is connected to the inlet of the transfer pump through a pipeline. The outlet of the transfer pump is connected to the mixer through a pipeline. The mixer is connected to the electro-desalting tank through a pipeline. A pump outlet regulating valve is provided on the pipeline between the transfer pump and the mixer. The pipeline on the left side of the pump outlet regulating valve is connected to a shunt pipeline. A reflux regulating valve is provided on the shunt pipeline. The shunt pipeline above the reflux regulating valve is connected to the branch mixer. The shunt pipeline between the branch mixer and the reflux regulating valve is connected to the demulsifier. The branch mixer is connected to the pipeline between the crude oil tank and the transfer pump through a shunt pipeline to form the mixing device for trace liquids.

[0007] For the mixing device for trace liquids, a butterfly mixer is provided on the pipeline between the crude oil tank and the transfer pump, and the mixing medium inlet pipe on the butterfly mixer is connected to the branch mixer.

[0008] For the mixing device for trace liquids, the butterfly mixer includes a mixing medium inlet pipe, a housing and a guide plate. At least one through hole penetrating to the inner edge surface of the housing is provided on the outer edge surface of the housing. The mixing medium inlet pipe is provided in the through hole. A guide plate is provided on the left side of the inner edge surface of the housing. A dumbbell-shaped hole is provided in the middle of the guide plate. A group of inwardly extending guide vanes are symmetrically provided on the side of the dumbbell-shaped hole. The end of the mixing medium inlet pipe passes through the through hole and extends above the inwardly extending guide vanes.

[0009] For the mixing device for trace liquids, the angle between the inwardly extending guide vanes and the end surface of the guide plate is 15° to 30°.

[0010] For the mixing device for trace liquids, the housing is of an annular structure.

[0011] For the mixing device for trace liquids, the guide plate is welded to the inner edge surface of the housing.

[0012] A mixing method for trace liquids, which is to lead out a shunt pipeline from the outlet pipeline of a delivery pump, reduce the mixing ratio of the demulsifier and the crude oil volume, enhance the mixing effect, set a pump outlet regulating valve on the pipeline downstream of the shunt pipeline, and set a reflux regulating valve on the shunt pipeline, so that part of the crude oil flows back from the shunt pipeline to the inlet of the delivery pump. The demulsifier is incorporated into the part of the crude oil flowing back in the shunt pipeline, and then enters a branch mixer arranged on the shunt pipeline. After mixing, it is transported to the pipeline from the inlet of the delivery pump, and then enters an electric desalting tank through the mixer for oil-water separation.

[0013] In the mixing method for trace liquids described above, the pump outlet regulating valve and the reflux regulating valve control the reflux ratio of the main crude oil in the crude oil tank to be 1:1000.

[0014] In the mixing method for trace liquids described above, the mixing ratio of the demulsifier and the reflux crude oil in the crude oil tank is set to 1:100.

[0015] Adopting the technical solution described above, the present invention has the following advantages:

[0016] The present invention leads out a shunt pipeline from the outlet pipeline of the delivery pump, mixes part of the crude oil led out from the shunt pipeline with the demulsifier, reduces the mixing ratio of the demulsifier and the crude oil volume, enhances the mixing effect, sets a pump outlet regulating valve on the pipeline downstream of the shunt pipeline, and sets a reflux regulating valve on the shunt pipeline, so that part of the crude oil flows back from the shunt pipeline to the inlet of the delivery pump. The demulsifier is incorporated into the part of the crude oil flowing back in the shunt pipeline, and then enters a branch mixer arranged on the shunt pipeline, and then enters an electric desalting tank for oil-water separation, etc. The present invention has the characteristics of simplicity and good mixing effect, and is suitable for wide promotion and application. Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of an existing mixing device;

[0018] Figure 2 is a schematic structural diagram of the mixing device in the embodiment of the present invention;

[0019] Figure 3 is a second schematic structural diagram of the mixing device in the embodiment of the present invention;

[0020] Figure 4 is a schematic structural diagram of the butterfly mixer in the embodiment of the present invention;

[0021] Figure 5 is Figure 4 a left-view structural diagram of;

[0022] Figure 6 is a schematic structural diagram of the guide plate in the embodiment of the present invention;

[0023] In the figure: 1. Crude oil tank; 2. Transfer pump; 3. Demulsifier; 4. Pipeline; 5. Mixer; 6. Electrostatic desalting tank; 7. Branch mixer; 8. Return regulating valve; 9. Pump outlet regulating valve; 10. Butterfly mixer; 101. Mixed medium inlet pipe; 102. Outer shell; 103. Deflector; 104. Main fluid; 105. Fluid to be mixed; 106. Inner extended deflector blade; 107. Dumbbell-shaped hole. Detailed implementation mode

[0024] The present invention can be more detailedly explained through the following embodiments, and the present invention is not limited to the following embodiments;

[0025] First of all, it should be noted that the orientation or positional relationship indicated by "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. adopted by the present invention when describing the structure is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of description and simplification of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention.

[0026] Combined with the attached Figures 2 to 6 A mixing device for trace liquids shown, including a crude oil tank 1, a transfer pump 2, a mixer 5, an electrostatic desalting tank 6, a branch mixer 7, a return regulating valve 8 and a pump outlet regulating valve 9. The crude oil tank 1 is connected to the inlet of the transfer pump 2 through a pipeline 4. The outlet of the transfer pump 2 is connected to the mixer 5 through a pipeline 4. The mixer 5 is connected to the electrostatic desalting tank 6 through a pipeline 4. A pump outlet regulating valve 9 is provided on the pipeline 4 between the transfer pump 2 and the mixer 5. The pipeline 4 on the left side of the pump outlet regulating valve 9 is connected to a shunt pipeline. A return regulating valve 8 is provided on the shunt pipeline. The shunt pipeline above the return regulating valve 8 is connected to the branch mixer 7. The shunt pipeline between the branch mixer 7 and the return regulating valve 8 is connected to the demulsifier 3. The branch mixer 7 is connected to the pipeline 4 between the crude oil tank 1 and the transfer pump 2 through a shunt pipeline to form the mixing device for trace liquids.

[0027] Furthermore, a butterfly mixer 10 is provided on the pipeline 4 between the crude oil tank 1 and the transfer pump 2, and the mixed medium inlet pipe 101 on the butterfly mixer 10 is connected to the branch mixer 7.

[0028] Furthermore, the structure of the butterfly static mixer is as Figure 4 、 5As shown in FIGS. 6, the butterfly static mixer includes a mixing medium inlet pipe 101, a housing 102 and a deflector 103. The housing 102 is of an annular structure. During implementation, since the length dimension of the housing 102 is relatively short, the frictional head loss along the way is reduced, enabling the kinetic energy of the fluid to be fully utilized for mixing. Also, due to the fewer mixing units, compared with the traditional static mixer with multiple series-connected plates, the possibility of blockage is greatly reduced, reducing the maintenance cost. At least one through hole penetrating from the outer edge surface to the inner edge surface of the housing 102 is provided on the outer edge surface of the housing 102. The central axis of the through hole forms an angle of 0° to 30° with the radial center of the housing 102. The mixing medium inlet pipe 101 is provided in the through hole and is welded in the through hole. A deflector 103 is provided on the left side of the inner edge surface of the housing 102. A dumbbell-shaped hole 107 is provided in the middle of the deflector 103. A set of inwardly extending deflector vanes 106 are symmetrically provided on the sides of the dumbbell-shaped hole 107. The angle between the inwardly extending deflector vanes 106 and the end surface of the deflector 103 is 15° to 30°. The end of the mixing medium inlet pipe 101 passes through the through hole and extends above the inwardly extending deflector vanes 106. During implementation, the mixing medium inlet pipe 101 radially penetrates the housing 102 and extends inwardly above the right side of the inwardly extending deflector vanes 106, so that the fluid 105 to be mixed and the main fluid 104 can undergo high-strength shear turbulent mixing through the inwardly extending deflector vanes 106.

[0029] When the main fluid 104 passes through the inwardly extending deflector vanes 106, due to the contraction of the flow channel area, the flow velocity of the main fluid 104 increases, and due to the flow disturbance of the inwardly extending deflector vanes 106, the turbulent intensity of the main fluid 104 increases. After passing through the inwardly extending deflector vanes 106, due to the sudden change of the flow channel cross-section, the velocity of the main fluid 104 decreases, and the kinetic energy of motion is converted into static pressure energy. The fluid 105 to be mixed downstream of the inwardly extending deflector vanes 106 flows out from the outlet of the mixing medium inlet pipe 101, and under the action of the viscous shear force, the fluid 105 to be mixed exchanges momentum with the main fluid 104 and flows downstream together with the main fluid 104. And due to the formation of an adverse pressure gradient downstream of the inwardly extending deflector vanes 106, an eddy is formed downstream of the inwardly extending deflector vanes 106 under the action of the adverse pressure gradient. Due to the energy dissipation of the eddy, the eddy continuously appears and disappears, so that alternately appearing eddies are formed.

[0030] The butterfly static mixer forms a swirling flow after the main fluid passes through the guide vanes by setting guide plates on the outer shell and guide vanes on the guide plates. At the same time, the fluid to be mixed enters the position near the guide vanes through the mixing medium inlet pipe. The fluid to be mixed changes its flow direction through the guide vanes, so that the fluid to be mixed shears with the main fluid at a predetermined angle and strengthens the turbulence, thereby enhancing the mixing effect, etc. The length of the present invention is greatly shortened compared with the traditional mixer and it is not easy to be blocked. Due to the shortened length, the frictional resistance loss along the way is reduced, so as to make full use of the pressure energy of the fluid to efficiently mix the two-phase flow, etc. The overall pressure drop of the present invention is small, the mixing effect is good, the overall structure is simple, the service life is long, and the cost is low, etc.

[0031] A mixing method for trace liquids. The mixing method is to lead out a shunt pipeline from the outlet pipeline 4 of the delivery pump 2, reduce the mixing ratio of the demulsifier 3 and the crude oil quantity, enhance the mixing effect, set a pump outlet regulating valve 9 on the pipeline 4 downstream of the shunt pipeline, set a reflux regulating valve 8 on the shunt pipeline, make part of the crude oil flow back from the shunt pipeline to the inlet of the delivery pump 2, the demulsifier 3 is incorporated into the part of the crude oil flowing back in the shunt pipeline, and then enters the branch mixer 7 arranged on the shunt pipeline. After mixing, it is transported from the inlet of the delivery pump 2 to the pipeline 4, and then enters the electric desalting tank 6 through the mixer 5 for oil-water separation.

[0032] During implementation, the pump outlet regulating valve 9 and the reflux regulating valve 8 control the reflux ratio of the main crude oil in the crude oil tank 1 to be 1:1000, and the mixing ratio of the demulsifier 3 and the reflux crude oil in the crude oil tank 1 is set to 1:100.

[0033] When the present invention is specifically implemented, the main medium to be mixed (crude oil) is abbreviated as the main medium, and the secondary medium to be mixed (demulsifier) is abbreviated as the secondary medium. A branch is led out from the outlet pipeline of the main medium delivery pump, and regulating valves are respectively arranged on the downstream pipeline of the branch outlet and the branch pipeline, so that part of the main medium flows back from the branch pipeline to the inlet of the delivery pump. The secondary medium is incorporated into the part of the main medium flowing back in the branch pipeline, and then enters the branch mixer arranged on the branch pipeline. After mixing, it is transported from the inlet of the delivery pump to the subsequent process flow. The pump outlet regulating valve and the reflux regulating valve are adjusted to control the reflux ratio of the main medium to be about 1:1000. The mixing ratio of the secondary medium and the refluxed main medium is about 1:100.

[0034] The present invention is a device and method for uniformly dispersing a trace fluid in the fluid where it is located after several processes and devices for at least two fluids with a large flow rate difference (in the order of 1:100000), that is, to achieve the best dispersion and mixing effect of the trace fluid.

[0035] The present invention has the following advantages:

[0036] 1. The present invention has a good mixing effect. It adjusts the mixing ratio of 1:100,000 under the existing process conditions to first perform mixing at a ratio of 1:100 and then at a ratio of 1:1,000. That is, it changes the original one-time mixing to two-time mixing and reduces the mixing ratio each time. Since the mixing ratio is reduced, the mixing effect will be significantly improved.

[0037] 2. The present invention has a simple operation process, makes small changes to the existing process flow, only requires adding several devices and pipelines, and can achieve a better mixing effect without excessive adjustment of process operation conditions.

[0038] 3. The present invention can adjust the reflux ratio and operation conditions according to the actual use working conditions and the properties of different raw materials, and has strong adaptability. When the properties of the same batch of secondary flow medium (demulsifier) change and the injection amount needs to be adjusted, the method of the present invention can also make corresponding on-line adjustments according to the situation.

[0039] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above methods. Similar replacement methods other than the above methods, such as changing the mixing ratio combination of the first and second mixings, changing the combination method of mixer types, etc., should be included in the protection scope of the present invention.

[0040] The parts not detailed in the present invention are the prior art.

[0041] The embodiments selected herein for disclosing the invention purpose of the present invention are currently considered suitable. However, it should be understood that the present invention is intended to include all changes and improvements of all embodiments belonging to the concept and scope of the invention.

Claims

1. A method for mixing trace liquids, characterized in that: The mixing method is to lead out a shunt pipeline from the outlet pipeline (4) of the transfer pump (2), reduce the mixing ratio of the demulsifier (3) and the crude oil volume, enhance the mixing effect, set a pump outlet regulating valve (9) on the pipeline (4) downstream of the shunt pipeline, and set a reflux regulating valve (8) on the shunt pipeline, so that part of the crude oil returns to the inlet of the transfer pump (2) from the shunt pipeline. The demulsifier (3) is incorporated into the part of the crude oil flowing back in the shunt pipeline, and then enters the branch mixer (7) provided on the shunt pipeline. After mixing, it is transported to the pipeline (4) from the inlet of the transfer pump (2), and then enters the electric desalting tank (6) through the mixer (5) for oil-water separation.

2. The method for mixing trace liquids according to claim 1, characterized in that: The pump outlet regulating valve (9) and the reflux regulating valve (8) control the reflux ratio of the main crude oil in the crude oil tank (1) to be 1:1000.

3. The method for mixing trace liquids according to claim 1, characterized in that: The mixing ratio of the demulsifier (3) and the reflux crude oil in the crude oil tank (1) is set to 1:

100.

4. The method for mixing trace liquids according to claim 1, characterized in that: The mixing method adopts the following mixing device. The mixing device includes a crude oil tank (1), a transfer pump (2), a mixer (5), an electric desalting tank (6), a branch mixer (7), a reflux regulating valve (8) and a pump outlet regulating valve (9). The crude oil tank (1) is connected to the inlet of the transfer pump (2) through a pipeline (4). The outlet of the transfer pump (2) is connected to the mixer (5) through a pipeline (4). The mixer (5) is connected to the electric desalting tank (6) through a pipeline (4). A pump outlet regulating valve (9) is provided on the pipeline (4) between the transfer pump (2) and the mixer (5). The pipeline (4) on the left side of the pump outlet regulating valve (9) is connected to the shunt pipeline. A reflux regulating valve (8) is provided on the shunt pipeline. The shunt pipeline above the reflux regulating valve (8) is connected to the branch mixer (7). The demulsifier (3) is connected to the shunt pipeline between the branch mixer (7) and the reflux regulating valve (8). The branch mixer (7) is connected to the pipeline (4) between the crude oil tank (1) and the transfer pump (2) through the shunt pipeline to form the mixing device for trace liquids.

5. The method for mixing trace liquids according to claim 4, characterized in that: A butterfly mixer (10) is provided on the pipeline (4) between the crude oil tank (1) and the transfer pump (2). The mixing medium inlet pipe (101) on the butterfly mixer (10) is connected to the branch mixer (7).

6. The method for mixing trace liquids according to claim 5, characterized in that: The butterfly mixer (10) includes a mixing medium inlet pipe (101), a housing (102) and a guide plate (103). At least one through hole penetrating to the inner edge surface of the housing (102) is provided on the outer edge surface of the housing (102). The mixing medium inlet pipe (101) is provided in the through hole. A guide plate (103) is provided on the left side of the inner edge surface of the housing (102). A dumbbell-shaped hole (107) is provided in the middle of the guide plate (103). A group of inward-extending guide vanes (106) are symmetrically provided on the side of the dumbbell-shaped hole (107). The end of the mixing medium inlet pipe (101) passes through the through hole and extends above the inward-extending guide vanes (106).

7. The method for mixing trace liquids according to claim 6, characterized in that: The angle between the inward-extending guide vanes (106) and the end surface of the guide plate (103) is 15° to 30°.

8. The method for mixing trace liquids according to claim 6, characterized in that: The housing (102) is of an annular structure.

9. The method for mixing trace liquids according to claim 6, characterized in that: The deflector plate (103) is welded to the inner edge surface of the housing (102).

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