A concentrated device for treating oil and gas field sewage

Abstract

The present application relates to sewage treatment technical field, specifically to a kind of oil and gas field sewage treatment concentration device, including separation tank, the side of separation tank is connected with liquid inlet pipe, upper end is connected with steam exhaust pipe, lower end is connected with slag discharge pipe;The inside of separation tank is equipped with heat exchange tank, the inside of heat exchange tank is mutually separated with the inside of separation tank, the middle of heat exchange tank is equipped with up and down through circulation channel, the upper end of separation tank is equipped with push flow device, push flow device is inserted into circulation channel, and push water flow downward;Multiple condenser pipes are arranged in heat exchange tank, and the upper and lower ends of the condenser pipes are communicated with the inside of the separation tank;Steam exhaust pipe is connected to steam compressor, and the gas outlet end of steam compressor is connected with steam inlet pipe, which is connected to the heat exchange tank after being inserted into the separation tank;The present application cancels the forced circulation pump, a large number of pipeline and other structures of existing equipment, which greatly reduces the equipment cost and energy consumption cost.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a wastewater treatment and concentration device for oil and gas fields. Background Technology

[0002] Oil and gas field extraction generates a large amount of wastewater containing high salt, high hardness, trace amounts of oil and suspended solids. It is usually concentrated for subsequent treatment. MVR evaporators (mechanical vapor recompression evaporators) have become the mainstream equipment for oil and gas field wastewater concentration due to their advantage of not requiring a continuous external steam supply.

[0003] Currently, most MVR (Mechanical Vapor Retention) thickening units used in oil and gas fields adopt a split layout, with the vapor-liquid separator, independent heat exchanger, forced circulation pump, and steam compressor arranged separately to form a dual external vapor-liquid circulation structure. The treatment process is as follows: the wastewater to be treated is preheated and then enters the vapor-liquid separator. The forced circulation pump extracts the concentrated brine from the bottom of the separator and pressurizes it to the external heat exchanger. In the heat exchanger, it exchanges heat with the secondary steam that has been pressurized and heated by the steam compressor. After being heated to the boiling point, it returns to the separator for flash evaporation. The generated secondary steam is separated into vapor and liquid and then enters the steam compressor. After being pressurized and heated, it forms an external circulation and re-enters the external heat exchanger as a heat source. The concentrate is discharged after reaching the target concentration, and the condensate is recycled.

[0004] This structure relies on an external forced circulation pump to maintain material circulation, which not only results in high overall energy consumption, but also poses a risk of leakage due to the mechanical seal of the circulation pump and numerous external pipeline flanges. Furthermore, the external circulation pipeline has dead zones, making it easy for salt crystals and oil stains to accumulate and form scale. Additionally, the heat dissipation loss of the connecting pipelines of the separate equipment is high, and the entire set of equipment has complex pipelines and occupies a large space. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide an oil and gas field wastewater treatment and concentration device to solve the problems of high energy consumption, numerous pipelines and easy scaling, and large space occupation of existing evaporation equipment.

[0006] The technical solution adopted in this invention is as follows: an oil and gas field wastewater treatment and concentration device includes a separation tank, one side of which is connected to an inlet pipe, the upper end of which is connected to a steam discharge pipe, and the lower end of which is connected to a slag discharge pipe; a heat exchange tank is provided inside the separation tank, the interior of which is separated from the interior of the separation tank, and a circulating channel running vertically through the middle of the heat exchange tank; a flow promoter is provided at the upper end of the separation tank, which extends into the circulating channel and pushes the water flow downward; multiple condenser tubes are provided in the heat exchange tank, and both the upper and lower ends of the condenser tubes are connected to the interior of the separation tank; the steam discharge pipe is connected to a steam compressor, and the steam compressor's outlet end is connected to a steam inlet pipe, which extends into the separation tank and then connects to the heat exchange tank.

[0007] The principle of the technical solution: The inlet pipe is used to introduce wastewater (raw water) that has reached a certain temperature after passing through the preheater. The wastewater gradually submerges the heat exchange tank. Then, the flow promoter is activated, pushing the wastewater downwards in the circulation channel, squeezing out the wastewater below. The squeezed-out wastewater enters the condenser tube and flows out from the top, thus achieving water circulation inside the separator. The steam compressor is activated to draw steam from the top of the separator (extra steam can be added when the equipment is first started). After compression, the steam temperature increases, and the high-temperature steam enters the heat exchange tank, making full contact with the condenser tube to form condensate. The condenser tube contains circulating low-temperature wastewater, which absorbs heat and evaporates to replenish the water in the separator. The steam is generated, thus forming a steam cycle. By realizing dual circulation and heat exchange of water and steam within the separator, the forced circulation pump and numerous pipelines of existing equipment are eliminated, significantly reducing equipment and energy costs. Furthermore, the invention is integrated within the separator, occupying minimal space. Additionally, because the invention uses a flow booster to push the water flow downwards, it pushes fixed waste materials and heavier impurities from the concentrated wastewater to the bottom of the tank, while the lighter wastewater flows upwards, reducing the rate of scaling in the condenser tubes. Moreover, when cleaning slag or concentrated waste, the slag flows directly from the lower slag discharge pipe. Clean water or wastewater can be injected into the separator, and the flow booster can be activated to use the accelerated water to assist in slag removal.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0009] 1. This invention integrates the heat exchange tank and the separation tank into a single unit. By setting up a flow promoter, the wastewater circulates and continuously concentrates within the heat exchange tank and the separation tank through the circulation channel and condenser. The steam generated in the separation tank is heated by a steam compressor and then enters the heat exchange tank to continuously heat and concentrate the wastewater. This invention eliminates the need for a forced circulation pump and a large number of pipelines, significantly reducing costs. Moreover, the overall device occupies little space, has low site requirements, and is applicable to a wider range of situations.

[0010] 2. This invention features a circulating channel running vertically through the middle of the heat exchange tank. A flow pusher installed in the circulating channel pushes the wastewater downwards, allowing the wastewater to circulate and concentrate. On the other hand, the water pressure generated by the flow can drive heavier impurities and concentrated components downwards, eventually allowing them to settle naturally at the bottom of the separator. This effectively slows down the scaling rate on the condenser tubes and the upper part of the heat exchange tank, reduces maintenance frequency, extends service life, and facilitates the discharge of settled impurities and components from the slag discharge pipe.

[0011] In a preferred embodiment of the present invention, the propeller includes a motor fixed to the upper end of the separation tank, the output shaft of the motor extending into the circulation channel and having multiple propeller blades fixed thereon.

[0012] Beneficial effects: The motor is used to drive the propulsion blades to rotate. The propulsion blades have an arc shape and are used to push the sewage downward.

[0013] In a preferred embodiment of the present invention, a partition plate is fixed in the separation tank. The partition plate is located below the heat exchange tank and divides the lower end of the separation tank into a circulation chamber and a settling chamber. The partition plate is provided with a plurality of slag discharge holes that are wider at the top and narrower at the bottom.

[0014] Beneficial effects: The isolation plate divides the lower end of the separator into a circulation chamber and a settling chamber. Wastewater in the circulation chamber flows directly back into the condenser tube, while the settling chamber is used to place settled impurities and concentrated waste. The two chambers are connected by a slag discharge hole, which is wider at the top and narrower at the bottom. This does not affect the flow of wastewater but effectively prevents heavier impurities and concentrated components from flowing back into the condenser tube, further reducing the scaling rate of the condenser tube and extending its service life. When cleaning waste residue or concentrated waste, the slag discharge hole reduces the downward flow area of ​​wastewater, thereby increasing its flow rate and further enhancing the flushing effect on waste residue or concentrated waste.

[0015] In a preferred embodiment of the present invention, the slag discharge hole is a strip-shaped hole or a circular hole.

[0016] Beneficial effects: The slag discharge hole can be any shape, but it is wider at the top and narrower at the bottom. The strip-shaped hole is more suitable for discharging concentrated waste downwards. The circular hole has a better effect in preventing backflow. Other shapes that are wider at the top and narrower at the bottom can also be used.

[0017] In a preferred embodiment of the present invention, the upper end of the heat exchange tank forms an inwardly recessed groove, and the upper end of the heat exchange tank is funnel-shaped.

[0018] Beneficial effects: This shape allows wastewater flowing out of the condenser to flow back into the circulation channel more easily. During normal operation and when the water level drops, it can more effectively carry the concentrated components and impurities into the circulation channel, preventing them from settling in other parts of the separator.

[0019] In a preferred embodiment of the present invention, the upper end of each condenser tube is bent, and the upper ends of several condenser tubes are sequentially formed with tangential outlets along the circumferential direction.

[0020] Beneficial effects: The condenser tube is curved and the outlet is tangentially formed along the circumference. Combined with the funnel-shaped heat exchange tank, the backflowing sewage can flow in a spiral inward, further enhancing the effect of removing impurities and concentrating waste.

[0021] In a preferred embodiment of the present invention, the heat exchange tank is provided with a flow divider ring, which is connected to the steam inlet pipe and has multiple branch pipes connected to it; the lower ends of the flow divider ring and the multiple branch pipes are all provided with flow divider holes.

[0022] Beneficial effects: The diversion ring and branch pipe are used to extend the steam inlet pipe and distribute the steam evenly to various positions of the heat exchange tank through the diversion hole, so that the condenser tubes at different positions work evenly and avoid the condenser tubes on the side close to the steam inlet pipe aging too quickly.

[0023] In a preferred embodiment of the present invention, the lower end of the heat exchange tank is connected to a condensate pipe, which extends out of the separation tank.

[0024] Beneficial effect: The condensate pipe is used to drain the condensate formed on the outer surface of the condensate pipe, so as to avoid the accumulation of condensate and affect the concentration effect of wastewater.

[0025] In a preferred embodiment of the present invention, the separation tank includes a tank body and a tank cover, wherein the tank cover is detachably mounted on the tank body.

[0026] Beneficial effects: The can lid can be disassembled and connected to the can body with a large number of bolts. During subsequent maintenance, the can lid can be removed after the steam exhaust pipe (which is usually made up of multiple pipe sections connected together, and only one part needs to be disassembled) is disassembled, making it convenient to clean the scale inside the condenser pipe.

[0027] In a preferred embodiment of the present invention, the slag discharge pipe is equipped with a control valve.

[0028] Beneficial effect: The control valve is used to control the opening and closing of the slag discharge pipe. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the oil and gas field wastewater treatment and concentration device of the present invention.

[0030] Figure 2 This is a plan sectional view of the oil and gas field wastewater treatment and concentration device of the present invention.

[0031] Figure 3 This is a three-dimensional sectional view of the oil and gas field wastewater treatment and concentration device of the present invention.

[0032] Figure 4 The oil and gas field wastewater treatment and concentration device of the present invention is based on Figure 3 A magnified view of detail A.

[0033] The reference numerals in the accompanying drawings include: 1. Separator tank; 2. Inlet pipe; 3. Steam outlet pipe; 4. Slag discharge pipe; 5. Heat exchange tank; 6. Circulation channel; 7. Flow booster; 8. Condenser pipe; 9. Steam compressor; 10. Steam inlet pipe; 11. Motor; 12. Flow booster blade; 13. Isolation plate; 14. Slag discharge hole; 15. Groove; 16. Diverter ring; 17. Branch pipe; 18. Diverter hole; 19. Condensate pipe; 20. Tank body; 21. Tank cover; 22. Control valve. Detailed Implementation

[0034] Typical embodiments embodying the features and advantages of the present invention will be specifically described in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0035] In the description of this invention, the terms "first," "second," "side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the structure referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0036] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] As attached Figure 1 As shown, the present invention provides an oil and gas field wastewater treatment and concentration device: including a separation tank 1, the separation tank 1 including a tank body 20 and a tank cover 21, the tank cover 21 being detachably mounted on the tank body 20; a liquid inlet pipe 2 is connected to one side of the separation tank 1, the tank cover 21 is connected to a steam discharge pipe 3, the slag discharge pipe 4 is equipped with a control valve 22, the control valve 22 being used to control the opening and closing of the slag discharge pipe 4; the steam discharge pipe 3 is connected to a steam compressor 9, the steam compressor 9 having a steam inlet pipe 10 connected to its outlet end, and the liquid inlet pipe 2 being used to introduce wastewater (raw water) that has reached a certain temperature after passing through a preheater.

[0038] As attached Figure 2 As shown, in this embodiment, the separation tank 1 has a heat exchange tank 5 inside, and the interior of the heat exchange tank 5 is separated from the interior of the separation tank 1. The heat exchange tank 5 has a circulating channel 6 running vertically through the middle. The upper end of the separation tank 1 has a pusher 7, which includes a motor 11 fixed to the upper end of the tank cover 21. The output shaft of the motor 11 extends into the circulating channel 6 and is fixed with multiple pusher blades 12. The motor 11 is used to drive the pusher blades 12 to rotate. The pusher blades 12 have an arc shape and are used to push the sewage downward. The heat exchange tank 5 has multiple condenser tubes 8, and both ends of the condenser tubes 8 are connected to the interior of the separation tank 1. The steam inlet pipe 10 extends into the separation tank 1 and is connected to the heat exchange tank 5. The lower end of the heat exchange tank 5 is connected to a condensate pipe 19, which extends out of the separation tank 1. The condensate pipe 19 is used to discharge the condensate formed on the outer surface of the condenser tubes to avoid the accumulation of condensate affecting the concentration effect of the sewage.

[0039] In practical use, wastewater is introduced into the separator 1 through the inlet pipe 2, gradually submerging the heat exchange tank 5. Then, the motor 11 is started, and the pusher blades 12 push the wastewater in the circulation channel 6 downwards. Under the pressure of the water flow, the wastewater enters the condenser tube 8 from the lower end and flows out from the top, thus realizing water circulation inside the separator 1. The steam compressor 9 is started to draw out the steam from the upper end of the separator 1 (extra steam can be added when the equipment is first started). After compression, the steam temperature increases, and the high-temperature steam enters the heat exchange tank 5, making full contact with the condenser tube 8 to form condensate. The condenser tube 8 contains circulating low-temperature wastewater, which absorbs heat and evaporates to replenish the steam in the separator 1. This creates a steam cycle. By achieving dual circulation and heat exchange of water and steam within the separator 1, the forced circulation pump and numerous pipelines of existing equipment are eliminated, significantly reducing equipment and energy costs. Furthermore, the invention is integrated within the separator 1, minimizing space requirements. Additionally, the downward-moving pusher 7 pushes the water flow downwards, removing solid waste and heavier impurities from the concentrated wastewater to below the tank 20, while the upward-flowing wastewater is primarily lighter, reducing the rate of scaling in the condenser tube 8. Moreover, when cleaning slag or concentrating waste, the slag flows directly from the lower slag discharge pipe 4. Clean water can be injected into the separator 1, or wastewater can be used to activate the pusher 7, using accelerated water to assist in slag removal.

[0040] As attached Figure 2 As shown, in this embodiment, a partition plate 13 is fixed in the separation tank 1. The partition plate 13 is located below the heat exchange tank 5 and has multiple slag discharge holes 14 that are wider at the top and narrower at the bottom. The partition plate 13 divides the lower end of the separation tank 1 into two chambers. The settling chamber is used for settling impurities and concentrated waste. The two are connected through the slag discharge holes 14. The slag discharge holes 14 are wider at the top and narrower at the bottom, which does not affect the inflow and outflow of sewage, but can effectively prevent heavier impurities and concentrated components from flowing back into the condenser tube 8, further reducing the scaling rate of the condenser tube 8 and extending its service life. When cleaning waste residue or concentrated waste, the slag discharge holes 14 can reduce the channel area for sewage to flow downward, thereby increasing its flow rate and further enhancing the effect of flushing waste residue or concentrated waste.

[0041] As attached Figure 2 As shown, in this embodiment, the upper end of the heat exchange tank 5 forms an inwardly recessed groove 15, and the upper end of the heat exchange tank 5 is funnel-shaped. This shape makes the sewage flowing out of the condenser 8 more likely to flow back into the circulation channel 6. During normal operation and when the water level drops, it can more effectively carry the concentrated components and impurities into the circulation channel 6, avoiding deposition in other positions of the separator 1.

[0042] As attached Figure 3 and Figure 4As shown, in this embodiment, the heat exchange tank 5 is provided with a flow divider ring 16, which is connected to the steam inlet pipe 10 and has multiple branch pipes 17 connected to it. The lower ends of the flow divider ring 16 and the multiple branch pipes 17 are all provided with flow divider holes 18. The flow divider ring 16 and the branch pipes 17 are used to extend the steam inlet pipe 10 and to distribute the steam evenly to various positions of the heat exchange tank 5 through the flow divider holes 18, so that the condenser tubes 8 at different positions work evenly and to avoid the condenser tubes 8 on the side close to the steam inlet pipe 10 aging too quickly.

[0043] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A wastewater treatment and concentration device for oil and gas fields, characterized in that: The system includes a separator, with an inlet pipe connected to one side, a steam outlet pipe connected to the upper end, and a slag discharge pipe connected to the lower end. Inside the separator is a heat exchange tank, separated from the separator. A circulating channel runs vertically through the middle of the heat exchange tank. A flow promoter is located at the upper end of the separator, extending into the circulating channel and propelling water downwards. The heat exchange tank contains multiple condenser tubes, both ends of which are connected to the separator's interior. The steam outlet pipe connects to a steam compressor, and the compressor's outlet is connected to a steam inlet pipe that extends into the separator and connects to the heat exchange tank. A condensate pipe extends from the lower end of the heat exchange tank to the outside of the separator.

2. The oil and gas field wastewater treatment and concentration device according to claim 1, characterized in that: The propeller includes a motor fixed to the upper end of the separation tank, the output shaft of the motor extending into the circulation channel and having multiple propulsion blades fixed thereon.

3. The oil and gas field wastewater treatment and concentration device according to claim 1, characterized in that: A partition plate is fixed in the separation tank. The partition plate is located below the heat exchange tank. The partition plate divides the lower end of the separation tank into a circulation chamber and a settling chamber. The partition plate is provided with multiple slag discharge holes that are wider at the top and narrower at the bottom.

4. The oil and gas field wastewater treatment and concentration device according to claim 3, characterized in that: The slag discharge hole is either a strip-shaped hole or a circular hole.

5. The oil and gas field wastewater treatment and concentration device according to claim 1, characterized in that: The upper end of the heat exchange tank forms an inwardly recessed groove, and the upper end of the heat exchange tank is funnel-shaped.

6. The oil and gas field wastewater treatment and concentration device according to claim 5, characterized in that: The upper end of each condenser tube is curved, and the upper ends of several condenser tubes are sequentially formed with tangential outlets along the circumferential direction.

7. The oil and gas field wastewater treatment and concentration device according to claim 1, characterized in that: The heat exchange tank is equipped with a flow divider ring, which is connected to the steam inlet pipe and has multiple branch pipes connected to it; the lower ends of the flow divider ring and the multiple branch pipes are all provided with flow divider holes.

8. The oil and gas field wastewater treatment and concentration device according to claim 1, characterized in that: The separation tank includes a tank body and a tank cover, the tank cover being detachably mounted on the tank body.

9. The oil and gas field wastewater treatment and concentration device according to claim 1, characterized in that: The slag discharge pipe is equipped with a control valve.

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