Skid-mounted treatment equipment for coal bed gas drainage and mining water

Abstract

The utility model discloses skid-mounted treatment equipment for coal bed gas drainage and mining water, which is characterized in that the instantaneous flow rate of the drainage and mining water is matched with the stable and efficient treatment of the treatment equipment according to the characteristics of the coal bed gas drainage and mining water, and the chemical consumption per ton of water is reduced. Comprising a skid-mounted container (7), a coal bed gas discharged and collected water adjusting tank (101) and a sludge airing tank (8), the coal bed gas discharged and collected water adjusting tank (101) is communicated with a coagulation reaction barrel (102) in the skid-mounted container (7) through a discharged and collected water input pipeline (109), and a discharged and collected water input water pump (110) is arranged on the discharged and collected water input pipeline. A discharged and collected water coagulation reaction mechanism (1), a discharged and collected water flocculation reaction mechanism (2), a precipitation clarification mechanism (3), a filtering mechanism (4), an ultrafiltration mechanism (5) and a power supply and control unit mechanism (6) are respectively arranged in the skid-mounted container (7), and coal bed gas discharged and collected water is arranged in the coal bed gas discharged and collected water adjusting tank.

Description

Technical Field

[0001] The present invention relates to a water treatment device, and particularly to a skid-mounted treatment device for coalbed methane drainage water and its working method. Background Art

[0002] During the process of coalbed methane extraction, drainage water is generated along with the extraction of the gas being mined. Coalbed methane drainage water is characterized by a large discharge volume and high pollutant content, and has become an important pollution source in the process of coalbed methane production. The drainage water contains pollutants such as suspended solids, organic matter, fluorides, and petroleum substances. In particular, the chemical agents used in coalbed methane drilling and extraction will also enter the coalbed methane drainage water during well drilling, causing serious water pollution to the drainage water. The existing coalbed methane wells are relatively scattered, generally scattered in mountainous and hilly areas with farmland and rivers nearby. The drainage water generated by multiple gas wells on-site is generally collected, and the collected drainage water should be treated to remove the pollutants in the water. The treated drainage water can be reused in the coalbed methane extraction production, and the remaining water is discharged locally into the surface river. Therefore, the pollution treatment of coalbed methane drainage water has become a top priority for local society and production enterprises.

[0003] The main pollutants in coalbed methane drainage water are suspended solids, colloids, macromolecular organic matter and ammonia nitrogen pollution. The drainage water is ink-colored and has poor sensory properties. It is a typical inorganic wastewater. The components of suspended solids are mainly fine particles such as coal dust, rock powder, clay, etc., especially coal powder, which contains tens to hundreds of milligrams per liter of water. In addition, the suspended solids have small particle size, light specific gravity and slow sedimentation rate. The drainage water is generally treated by coagulation → sedimentation → sand filtration → ultrafiltration, which can remove most of the suspended solids and a small amount of organic matter. Ammonia nitrogen is reduced to zero by using ammonia nitrogen remover. For the treatment of coalbed methane drainage water, if it is treated in the same way as traditional industrial wastewater, it is necessary to establish a ground sewage treatment station, expropriate land and equip corresponding water treatment equipment, which has the disadvantages of long construction time and large land area. Due to the dispersion of coalbed methane wells and the limited continuous mining time, it is neither economical nor practical to equip a ground fixed sewage treatment station next to the gas well. The production of coalbed methane is mainly divided into two stages. The first stage The first stage is the well drilling stage, during which some chemical agents will be used. These agents enter the well during the drilling process and are pumped to the ground with the drainage water. The pollutant content in this part of the water is relatively high, and it belongs to the category of key treatment time period; the second stage is the sub-production stage, which is the stage of stably extracting coalbed methane from the well. The pollutants in the water extracted in this stage will be greatly reduced; therefore, how to design a movable integral drainage water treatment equipment to transform the fixed attributes of traditional sewage treatment facilities into a movable integrated sewage treatment equipment not only has great economic value, but also involves the problem of overcoming technical difficulties. How to arrange the whole process unit of sewage treatment in a limited movable space puts forward a new requirement for the structure of the skid-mounted treatment equipment. At the same time, for the overall skid-mounted equipment, how to improve the operating load and stability of the treatment equipment and reduce the drug consumption per ton of water under the condition of certain water treatment surface load has also become a difficult problem that the skid-mounted equipment needs to overcome. Summary of the invention

[0004] The present invention provides a skid-mounted treatment device for coalbed methane drainage water, which matches the instantaneous flow of drainage water with the stable and efficient treatment of the treatment device according to the characteristics of coalbed methane drainage water, and reduces the consumption of medicine per ton of water.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The general concept of the present invention is as follows: The equipment for treating coalbed methane drainage water is centrally arranged in a skid-mounted container to achieve the convenient movement and efficient treatment of the entire water treatment equipment; according to the pollution characteristics of coalbed methane drainage water, the coagulation device and flocculation device in the skid-mounted equipment are creatively designed to save the dosage of chemicals and efficiently treat sewage; the flocculation stirrer of the coagulation device of the present invention is a combined mixer, with a propeller mixer installed on the upper part and a frame mixer on the lower part. They are installed on the same rotating shaft and rotate simultaneously. The frame mixer has a large contact area with water and a large amount of disturbed materials. The mixing medium only has horizontal shear and disturbance, without axial disturbance. Therefore, compared with the propeller mixer, the frame mixer has the characteristics of low mixing intensity and a large amount of disturbed materials, which conforms to the law of particle flocculation and is conducive to generating larger flocculation prototypes; the present invention transforms the channel between the mechanical stirring flocculation reaction tank and the inclined tube sedimentation tank into a hydraulic micro-flocculation reaction channel, and the test effect is better. The main principle is that the cross-sectional area of the micro-flocculation channel changes with the contraction and expansion of the cross-section, so the water velocity also changes continuously, generating a velocity gradient to promote the collision of particles, making the flocs continue to grow larger and easier to be removed in the inclined tube sedimentation tank.

[0007] A skid-mounted treatment equipment for coalbed methane drainage water includes a skid-mounted container, a coalbed methane drainage water regulation tank, and a sludge drying pond. The coalbed methane drainage water regulation tank is connected to the coagulation reaction device in the skid-mounted container through a drainage water input pipeline. A lift pump is arranged on the drainage water input pipeline. In the skid-mounted container, there are respectively arranged a coalbed methane drainage water coagulation reaction mechanism, a coalbed methane drainage water flocculation reaction mechanism, an inclined tube sedimentation mechanism 3, a filtration mechanism, an ultrafiltration mechanism, and an intelligent control device. Coalbed methane drainage water is arranged in the coalbed methane drainage water regulation tank; a partition plate is arranged in the coagulation reaction device of the coalbed methane drainage water coagulation reaction mechanism. The partition plate divides the inner cavity of the coagulation reaction device into a coagulation zone and a flocculation zone. A double-stage propeller paddle coagulation stirrer is arranged in the coagulation zone. In the flocculation zone, an upper flocculation mixing and stirring zone and a lower flocculation discharging zone are arranged from top to bottom. A flocculation stirrer is arranged in the flocculation zone. On the stirring shaft of the flocculation stirrer, there are respectively arranged an upper propeller stirring blade and a lower frame stirring blade. The upper propeller stirring blade is arranged in the upper flocculation mixing and stirring zone, and the lower frame stirring blade is arranged in the lower flocculation discharging zone; a flow-pushing partition plate is arranged in the flocculation reaction device of the coalbed methane drainage water flocculation reaction mechanism. The flow-pushing partition plate divides the inner cavity of the flocculation reaction device into a flocculation reaction zone and a flow-pushing zone. The flow-pushing zone is a wavy channel; a coagulant dosing pipe is connected to the drainage water input pipeline, and the other end of the coagulant dosing pipe is connected to a coagulant dosing device; the output port of a flocculant dosing pipe is arranged in the upper flocculation mixing and stirring zone, and the other end of the flocculant dosing pipe is connected to a flocculant dosing device.

[0008] The rotational speed of the double-stage propulsion paddle type coagulation stirrer is 120 revolutions per minute, and the rotational speed of the flocculation stirrer is 60 revolutions per minute; the diameter of the upper propulsion type stirring blade is twice that of the propulsion type stirring blade on the double-stage propulsion type coagulation stirrer; a flocculation stirring lifting cylinder is arranged in the flocculation reaction zone, and the water outlet of the coagulation reaction water outlet pipe is arranged at the bottom port of the flocculation stirring lifting cylinder. The other end of the coagulation reaction water outlet pipe is arranged at the lower part of the coagulation reaction device. The coagulation reaction device and the flocculation reaction device are connected together through the coagulation reaction water outlet pipe; a double-stage propulsion paddle type flocculation stirrer is arranged in the flocculation stirring lifting cylinder; on the middle pipe wall of the coagulation reaction water outlet pipe, an inclined sludge input pipe section is connected, and the other end of the sludge input pipe section is connected with the sludge return pipe through a sludge return pipeline pump.

[0009] The rotational speed of the double-stage propulsion type flocculation stirrer is 20 - 30 revolutions per minute, and the ratio of the diameter of the stirring impeller on the double-stage propulsion type flocculation stirrer to the diameter of the flocculation stirring lifting cylinder is 2:3; the ratio of the sludge volume entering the flocculation stirring lifting cylinder through the sludge input pipe section to the water volume entering the flocculation stirring lifting cylinder through the coagulation reaction water outlet pipe is 3 - 5%.

[0010] In the inclined tube sedimentation mechanism, an inclined tube clarification zone is arranged at the upper part of the inclined tube sedimentation zone, an inclined tube separation zone is arranged in the middle of the inclined tube sedimentation zone, a sediment sludge zone is arranged at the lower part of the inclined tube sedimentation zone, a water collecting trough is arranged in the inclined tube clarification zone, and triangular weir water outlets are arranged at the top ends of the vertical plates on both sides of the water collecting trough; inclined tube pipe rows are arranged in the inclined tube separation zone, and the included angle between the inclined tube pipe rows and the horizontal plane is 60 degrees; a sludge hopper is arranged in the middle of the sediment sludge zone, and an electric sludge scraper is arranged on the bottom end surface of the inclined tube sedimentation zone outside the sludge hopper; the inclined tube sedimentation zone is connected with the flocculation reaction zone through an overflow outlet.

[0011] A quartz sand filter layer is arranged in the homogeneous filtration device of the filtration mechanism, and air-water dual-purpose filter caps are arranged on the lower bottom surface of the quartz sand filter layer. The water inlet of the homogeneous filtration device is connected with the water outlet of the water collecting trough in the inclined tube sedimentation zone. A homogeneous filtration water outlet pipe is connected to the water outlet of the homogeneous filtration device, and the other end of the homogeneous filtration water outlet pipe is connected with the water inlet of the intermediate water tank. The water outlet of the intermediate water tank is connected with a precision filter through an ultrafiltration water pump. A precision filter water outlet pipe is connected to the output end of the precision filter. An ultrafiltration device is connected in series on the precision filter water outlet pipe. An ultrafiltration device water outlet pipe is arranged at the output end of the ultrafiltration device, and the other end of the ultrafiltration device water outlet pipe is connected with a purification water tank. A discharge water pipe is connected to the purification water tank.

[0012] A working method of a skid-mounted treatment device for coalbed methane drainage water is characterized by including the following steps:

[0013] Step 1: Turn on the lift pump to transport the coalbed methane drainage water in the coalbed methane drainage water regulation tank to the coagulation zone of the coagulation reaction device. At the same time, start the double-stage propeller-type coagulation stirrer and the water treatment agent dosing device, and add the aqueous solution of the water treatment agent into the drainage water input pipeline through the coagulant dosing pipe. The amount of coagulant added per ton of coalbed methane drainage water is 10 - 30 grams.

[0014] Step 2: When the water level of the coalbed methane drainage water entering the coagulation reaction device is higher than the top surface of the partition plate, start the flocculation stirrer and the flocculant dosing device simultaneously. The amount of flocculant added per ton of coalbed methane drainage water is 1 - 2 grams.

[0015] Step 3: Open the coagulation reaction outlet pipe, and regulate the inlet flowmeter to make the instantaneous flow rate of the inlet and outlet water of the coagulation reaction device 10 - 40 cubic meters per hour; and make the water level in the coagulation reaction device 15 - 200 millimeters higher than the top of the partition plate.

[0016] Step 4: According to the amount of water from the coagulation reaction device, start the sludge return pipeline pump, and transport 3 - 5% of the sludge to the flocculation stirring lifting cylinder through the inclined sludge input pipe section.

[0017] Step 5: The drainage water and sludge in the flocculation stirring lifting cylinder with alum flowers are mixed to generate flocs under the stirring of the double-stage propeller-type flocculation stirrer at 20 - 30 revolutions per minute. After overflowing from the upper port of the flocculation stirring lifting cylinder under the action of the propeller blades, it falls to the bottom of the flocculation reaction device. Most of the flocs at the bottom enter the plug flow zone through the water flow transition outlet, and a part of the flocs at the bottom returns to the flocculation stirring lifting cylinder through the lower port of the flocculation stirring lifting cylinder.

[0018] Step 6: The flocs entering the plug flow zone are repeatedly squeezed by the wave-shaped channel, making the flocs denser. Finally, they enter the inclined tube clarification zone with the water flow through the overflow channel.

[0019] Step 7: The flocs in the drainage water entering the inclined tube sedimentation zone sink to the sediment sludge zone. In the inclined tube reverse flow separation zone, the fine flocs are further removed on the inclined tubes. The clarified supernatant water flows into the recycled water tank by gravity after passing through the overflow trough; the water level in the sedimentation zone of the inclined tube sedimentation zone is higher than the bottom end of the triangular notch outlet and lower than the top end surfaces of the two vertical plates of the overflow trough.

[0020] Step 8: By regulating the drainage water input pump, construct a situation where the water level in the sedimentation tank is lower than the water level in the flocculation reaction barrel, so that the water level difference enables the coalbed methane drainage water to flow from the flocculation reaction device to the inclined tube sedimentation zone, making the water in each unit of the sewage treatment in the entire skid in a flowing state.

[0021] A sludge thickness detection sensor is arranged in the sedimentation sludge area. When the sludge thickness value detected by the sludge thickness detection sensor reaches the design value, the electric sludge scraper is started to scrape the sludge into the sludge hopper; a sludge return pipe is connected to the sludge hopper.

[0022] The beneficial effects of the present invention are as follows: (1) In view of the water quality characteristics of the drainage water, an integral skid-mounted treatment device and treatment process are creatively developed, which not only realizes the reduction of the chemical dosage for water treatment, but also realizes the stable operation of the equipment; (2) The overall skid-mounted equipment system has a reasonable layout, saves investment, is convenient for operation and management, and the overall equipment is movable, especially convenient for transfer and repeated use; (3) The on-site operation and management are convenient, and the labor intensity of the operators is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the overall structural schematic diagram of the present invention;

[0024] Figure 2 is the structural schematic diagram of the skid-mounted container 7 of the present invention in the top view direction;

[0025] Figure 3 is the structural schematic diagram of the drainage water coagulation reaction mechanism 1 of the present invention;

[0026] Figure 4 is the structural schematic diagram of the drainage water flocculation reaction mechanism 2 of the present invention;

[0027] Figure 5 is the structural schematic diagram of the inclined tube sedimentation mechanism 3 of the present invention;

[0028] Figure 6 is the structural schematic diagram of the filtration mechanism 4 and the ultrafiltration mechanism 5 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings:

[0030] A skid-mounted treatment device for coalbed methane drainage water includes a skid-mounted container 7, a coalbed methane drainage water regulating tank 100 and a sludge drying pond 8. The coalbed methane drainage water regulating tank 100 is connected to the coagulation reaction device 102 in the skid-mounted container 7 through a drainage water input pipeline 109. A drainage water input water pump 101 is arranged on the drainage water input pipeline 109. A drainage water coagulation reaction mechanism 1, a drainage water flocculation reaction mechanism 2, an inclined tube sedimentation mechanism 3, a filtration mechanism 4, an ultrafiltration mechanism 5 and an intelligent control device 6 are respectively arranged in the skid-mounted container 7. Coalbed methane drainage water is arranged in the coalbed methane drainage water regulating tank 100. The working method of the skid-mounted treatment device for coalbed methane drainage water includes the following steps:

[0031] Step 1: Turn on the lift pump 101 to transport the coalbed methane drainage water in the coalbed methane drainage water regulation tank 100 to the coagulation zone 104 of the coagulation reaction device 102. At the same time, turn on the double-stage propulsion paddle-type coagulation stirrer 107 and start the coagulant dosing device 115 to add the aqueous solution of the water treatment agent into the drainage water input pipeline 109 through the coagulant dosing pipe 114. The amount of coagulant added per ton of coalbed methane drainage water is 10 - 30 grams;

[0032] Step 2: When the water level 106 of the coalbed methane drainage water entering the coagulation reaction device 102 is higher than the top surface of the partition plate 103, turn on the flocculation stirrer 108 and the flocculant dosing device 117 simultaneously. The amount of flocculant added per ton of coalbed methane drainage water is 1 - 2 grams;

[0033] Step 3: Open the coagulation reaction outlet pipe 111 and regulate the inlet flowmeter 110 to make the instantaneous flow rate of the inlet and outlet water of the coagulation reaction device 102 10 - 40 cubic meters per hour; and make the water level 106 in the coagulation reaction device 102 15 - 200 millimeters higher than the top of the partition plate 103;

[0034] Step 4: According to the amount of water from the coagulation reaction device 102, start the sludge return pipeline pump 206 to transport 3 - 5% of the sludge through the inclined sludge input pipe section 207 to the flocculation stirring lift cylinder 202;

[0035] Step 5: The drainage water and sludge in the flocculation stirring lift cylinder with flocs are mixed under the stirring of the double-stage propulsion paddle-type flocculation stirrer 203 at 20 - 30 revolutions per minute to generate flocs. After overflowing from the upper port of the flocculation stirring lift cylinder 202 under the action of the propulsion paddle blades, they fall to the bottom of the flocculation reaction device 201. Most of the flocs at the bottom enter the plug flow zone 212 through the water flow transition outlet 204, and a part of the flocs at the bottom return to the flocculation stirring lift cylinder 202 through the lower port of the flocculation stirring lift cylinder 202;

[0036] Step 6: The flocs entering the plug flow zone 212 are repeatedly squeezed by the wave-shaped channel to make the flocs more dense. Finally, they enter the inclined tube clarification zone with the water flow from the overflow channel 213;

[0037] Step 7: The flocs in the drainage water entering the inclined tube sedimentation zone 301 sink to the sediment sludge zone 304. In the inclined tube reverse flow separation zone 303, the fine flocs are further removed on the inclined tubes. The clarified supernatant water flows into the recycled water tank by gravity after passing through the overflow trough 305; The water level 310 of the sedimentation tank in the inclined tube sedimentation zone 301 is higher than the bottom end of the triangular notch outlet 306 and lower than the top end surfaces of the two vertical plates of the overflow trough 305;

[0038] Step 8: By adjusting the influent flowmeter 110, construct the water level in the sedimentation tank 310 to be lower than the water level in the flocculation reaction device 201, so that the water level difference enables the flow of coalbed methane drainage water from the flocculation reaction device 201 to the inclined tube sedimentation area 301, making the water in each unit of the sewage treatment in the entire skid in a flowing state; a sludge thickness detection sensor is provided in the sediment sludge area 304. When the sludge thickness value detected by the sludge thickness detection sensor reaches the design value, start the electric sludge scraper 309 to scrape the sludge into the sludge hopper 308; a sludge return pipe 205 is connected to the sludge hopper 308.

[0039] The drainage water coagulation reaction mechanism 1 includes a coalbed methane drainage water regulating tank 100 and a coagulation reaction device 102. Coalbed methane drainage water is provided in the coalbed methane drainage water regulating tank 100. A partition plate 103 is provided in the coagulation reaction device 102. The partition plate 103 divides the inner cavity of the coagulation reaction device 102 into a coagulation zone 104 and a flocculation zone 105. A double-stage propulsion paddle type coagulation stirrer 107 is provided in the coagulation zone 104. In the flocculation zone 105, an upper flocculation mixing and stirring zone 1051 and a lower flocculation discharging zone 1052 are arranged from top to bottom. A flocculation stirrer 108 is provided in the flocculation zone 105. An upper propulsion type stirring blade 1081 and a lower frame type stirring blade 1082 are respectively arranged on the stirring shaft of the flocculation stirrer 108. The upper propulsion type stirring blade 1081 is arranged in the upper flocculation mixing and stirring zone 1051, and the lower frame type stirring blade 1082 is arranged in the lower flocculation discharging zone 1052; A drainage water input pipeline 109 is connected to the barrel wall at the lower end of the coagulation zone 104. The other end of the drainage water input pipeline 109 is arranged in the coalbed methane drainage water in the coalbed methane drainage water regulating tank 100. A lift pump 101 is provided on the drainage water input pipeline 109. The water level 106 in the coagulation reaction device 102 is higher than the top end of the partition plate 103. A coagulation reaction water outlet pipe 111 is provided on the barrel wall at the lower end of the flocculation zone 105; A coagulant dosing pipe 114 is communicated with the drainage water input pipeline 109. The other end of the coagulant dosing pipe 114 is communicated with a coagulant dosing device 115; An outlet of a flocculant dosing device 116 is provided in the upper flocculation mixing and stirring zone 1051. The other end of the flocculant dosing pipe 116 is communicated with a flocculant dosing device 117; The coagulant (PAC) solution in the coagulant dosing device 115 enters the drainage water input pipeline 109 through the coagulant dosing pipe 114, is mixed with the drainage water and then enters the coagulation zone 104 of the coagulation reaction device 102. Through the mixing and stirring of the double-stage propulsion paddle type coagulation stirrer 107, the water body moves upward at the same time. During the mixing process, the hydrolysis products of the coagulant (PAC) are quickly diffused to every detail in the water body, so that all colloidal particles are destabilized and aggregated almost at the same moment, laying a foundation for flocculation; This process relies on the lifting and mixing of the double-stage propulsion type coagulation stirrer 107 to complete the rapid coagulation reaction of the sludge, medicament and raw water, and then enters the flocculation zone 105 through the impeller lifting.

[0040] The rotation speed of the double-stage propeller type coagulation stirrer 107 is 120 revolutions per minute, and the rotation speed of the flocculation stirrer 108 is 60 revolutions per minute; the diameter of the upper propeller type stirring blade 1081 is twice that of the propeller type stirring blade on the double-stage propeller type coagulation stirrer 107; at the water inlet of the coagulation zone 104, after the coagulant is mixed with the produced water, it enters the coagulation zone 104 and is stirred and mixed by the high-speed rotating double-stage propeller type coagulation stirrer 107, so that the water treatment agent and the produced water fully undergo a chemical reaction. The water flow moves upward and overflows the partition plate 103 and enters the flocculation zone 105. The flocculation zone 105 is a slow reaction zone for generating the initial form of flocs. The flocculant dosing device 117 adds the flocculant into this area through the flocculant dosing pipe 116. The flocculation stirrer 108 stirs at a slower rotation speed of 60 revolutions per minute. In the present invention, a large-diameter upper propeller type stirring blade 1081 is arranged above the rotating shaft of the flocculation stirrer 108. Through the rotation of this blade, the downward flow rate of the water flow entering this area is slowed down, so that the entering water flow has a longer residence time in this area, and the water flow and the flocculant are fully stirred and reacted to generate more initial forms of flocs. These initial forms of flocs continue to move downward into the middle flocculation preliminary forming zone 1052, and the further stirring of the lower frame type stirring blade 1082 not only plays a stirring role, but also plays a role in protecting the initially formed flocs from being broken by the stirring of the blades; the plate-frame type stirring blades can be arranged in a horizontal form at the lower part of the rotating shaft of the flocculation stirrer 108, so as to minimize the destruction of the further enlarged flocs by stirring; generally, the residence time of the produced water in the flocculation zone 105 is controlled not to exceed 10 minutes, and the residence time in the flocculation zone 105 is between 15 minutes and 20 minutes, laying a good foundation for subsequent water treatment.

[0041] The coagulant dosing device 115 includes a stirrer, a tank body and a metering pump. The coagulant in the coagulant dosing device 115 is polyaluminum chloride. After being stirred with water, the coagulant is added to the produced water input pipeline 109 in the form of an aqueous solution of the water treatment agent; the flocculant dosing device 117 includes a stirrer, a tank body and a metering pump. The flocculant in the flocculant dosing device 117 is polyacrylamide. After being stirred with water, the flocculant is added to the upper flocculation mixing and stirring zone 1051 in the form of an aqueous solution of the flocculant.

[0042] An anti-fluoride agent dosing pipe 112 is connected to the produced water input pipeline 109, and the other end of the anti-fluoride agent dosing pipe 112 is connected to an anti-fluoride agent dosing device 113; to achieve the effect of defluorination.

[0043] The drainage and production water flocculation reaction mechanism 2 includes a flocculation reaction device 201. A flow-pushing channel partition plate 210 is arranged in the flocculation reaction device 201. The flow-pushing channel partition plate 210 divides the inner cavity of the flocculation reaction device 201 into a flocculation reaction zone 211 and a flow-pushing zone 212. The task of the flocculation reaction zone 211 is to adsorb pollutants such as suspended substances and colloids onto flocs, and the flow-pushing zone 212 is to complete the transportation of large flocs; a water flow transition outlet 204 from the flocculation reaction zone 211 to the flow-pushing zone 212 is arranged below the flow-pushing channel partition plate 210, and an over-flow outlet 213 from the flow-pushing zone 212 to the inclined tube clarification zone is arranged at the upper end of the flow-pushing zone 212; a flocculation stirring and lifting cylinder 202 is arranged in the flocculation reaction zone 211. The outlet of the water outlet pipe of the coagulation reaction water outlet pipe 111 is arranged inside the bottom port of the flocculation stirring and lifting cylinder 202. The other end of the coagulation reaction water outlet pipe 111 is arranged at the lower part of the coagulation reaction device 102. The coagulation reaction device 102 and the flocculation reaction device 201 are connected together through the coagulation reaction water outlet pipe 111; a double-stage propulsion paddle type flocculation stirrer 203 is arranged in the flocculation stirring and lifting cylinder 202; on the middle pipe wall of the coagulation reaction water outlet pipe 111, an inclined sludge input pipe section 207 is connected. The other end of the sludge input pipe section 207 is connected with a sludge return pipe 205 through a sludge return pipeline pump 206; the flow-pushing zone 212 is a wavy channel; the drainage and production water from the coagulation zone first enters the lower end of the flocculation stirring and lifting cylinder 202 through the coagulation reaction water outlet pipe 111. Then, under the pushing of the blades of the double-stage propulsion paddle type flocculation stirrer 203, it moves upward in the flocculation stirring and lifting cylinder 202, overflows from the upper port of the flocculation stirring and lifting cylinder 202 and then falls to the bottom of the flocculation reaction device 201, and then enters the flow-pushing zone 212 through the water flow transition outlet 204, rises to the over-flow outlet 213 along the flow-pushing zone 212, and finally overflows to the inclined tube sedimentation zone; the sludge return is pumped from the sludge hopper of the inclined tube clarification zone by the sludge return pipeline pump 206. The sludge in the sedimentation tank has a certain coagulation performance. The return of the sludge increases the suspended substances in the drainage and production water, and forms a sludge layer of flocs to a certain extent. The returned sludge particles can increase the sedimentation speed of the flocs. At the same time, the flocculation and adsorption effect of the biological flocs in the sludge can greatly improve the removal rate of pollutants, achieving the effect of strengthening the primary treatment, and at the same time, it can avoid excessive dosing of chemicals.

[0044] The rotation speed of the double-stage propulsion type flocculation stirrer 203 is 20 - 30 revolutions per minute. The ratio of the diameter of the upper stirring impeller of the double-stage propulsion type flocculation stirrer 203 to the diameter of the flocculation stirring and lifting cylinder 202 is 2:3; the ratio of the amount of sludge entering the flocculation stirring and lifting cylinder 202 through the sludge input pipe section 207 to the amount of water entering the flocculation stirring and lifting cylinder 202 through the coagulation reaction water outlet pipe 111 is 3 - 5%.

[0045] The described plug flow zone 212 is realized by arranging corrugated plates in the channel; a disinfectant dosing pipe 208 is connected to the coagulation reaction water outlet pipe 111, and a disinfectant dosing device 209 is connected to the other end of the disinfectant dosing pipe 208 to disinfect the produced water during drainage.

[0046] The inclined tube sedimentation mechanism 3 includes an inclined tube sedimentation zone 301, an inclined tube clarification zone 302 is arranged in the upper part of the inclined tube sedimentation zone 301, an inclined tube separation zone 303 is arranged in the middle of the inclined tube sedimentation zone 301, a sediment sludge zone 304 is arranged in the lower part of the inclined tube sedimentation zone 301, a water collecting tank 305 is arranged in the inclined tube clarification zone 302, and triangular weir water outlets 306 are arranged at the top ends of the vertical plates on both sides of the water collecting tank 305; an inclined tube row 307 is arranged in the inclined tube separation zone 303, and the included angle between the inclined tube row 307 and the horizontal plane is 60 degrees; a sludge hopper 308 is arranged in the middle of the sediment sludge zone 304, and an electric sludge scraper 309 is arranged on the bottom end surface of the inclined tube sedimentation zone 301 outside the sludge hopper 308; the inclined tube sedimentation zone 301 is connected to the flocculation reaction zone 211 through an overfall outlet 213; the bottom end surface of the inclined tube sedimentation zone 301 outside the sludge hopper 308 is an inclined surface inclined towards the center; the water level 310 of the inclined tube sedimentation zone in the inclined tube sedimentation zone 301 is higher than the bottom end of the triangular weir water outlet 306 and lower than the top end surfaces of the vertical plates on both sides of the water collecting tank 305; the cross section of each inclined tube in the inclined tube row 307 is hexagonal; the included angle between the inclined tube row 307 and the horizontal plane is 60 degrees, and this inclination can ensure that the sludge deposited on the inclined tubes can slide smoothly to the bottom without siltation. The cross section of each inclined tube in the inclined tube row 307 is hexagonal, and a larger effective sedimentation area can be obtained.

[0047] When the instantaneous flow rate of the influent and effluent water in the flocculation reaction zone 211 is 20 - 40 cubic meters per hour, the surface water load of the inclined tube row 307 is 10 cubic meters per square meter per hour. This surface water load well adapts to the characteristics of the coalbed methane produced water during drainage and effectively realizes the purification of the sewage; the water level 310 of the inclined tube sedimentation zone is lower than the water level in the flocculation reaction zone 211, and the water level difference between the two realizes the flow of the coalbed methane produced water from the flocculation reaction zone 211 to the inclined tube sedimentation zone 301, making the water in each unit of the sewage treatment in the whole skid in a flowing state.

[0048] The produced water that has formed flocs after flocculation reaction enters the inclined tube sedimentation zone to ensure that the flocs do not break, and then enters the sedimentation zone. The coagulation flocs precipitate to the bottom of the pool in this area. The upper part of the sedimentation zone is equipped with an inclined tube row, and its main function is to guide the flow and avoid the lateral flow of water, reducing the influence of the lateral flow on the sedimentation effect. In the inclined tube separation zone, the fine flocs are further removed on the inclined tubes, and the clarified supernatant water flows into the reused water tank by gravity after passing through the water collecting tank 305.

[0049] The filtering mechanism 4 and the ultrafiltration mechanism 5 include a homogeneous filtration device 401, an intermediate water tank 406, a precision filter 408, an ultrafiltration device 410, and a purification water tank 412. A quartz sand filtration layer 402 is provided in the homogeneous filtration device 401, and a water-air dual-purpose filtration cap 403 is provided on the lower bottom surface of the quartz sand filtration layer 402. The water inlet of the homogeneous filtration device 401 is communicated with the water outlet of the collecting tank 305. A homogeneous filtration effluent pipe 404 is connected to the water outlet of the homogeneous filtration device 401, and the other end of the homogeneous filtration effluent pipe 404 is connected to the water inlet of the intermediate water tank 406. The water flowing from the collecting tank 305 in the inclined plate sedimentation device by gravity, after being filtered by the quartz sand filtration layer 402, enters the intermediate water tank 406; the effluent pipe of the intermediate water tank 406 is connected to the precision filter 408 through an ultrafiltration water pump 407. A precision filter effluent pipe 409 is connected to the output end of the precision filter 408. An ultrafiltration device 410 is connected in series on the precision filter effluent pipe 409. An ultrafiltration device effluent pipe 411 is connected in series to the output end of the ultrafiltration device 410. The other end of the ultrafiltration device effluent pipe 411 is connected to a purification water tank 412. A discharged water pipe 413 is connected to the purification water tank 412; the water in the intermediate water tank 406 enters the purification water tank 412 after passing through the precision filter and the ultrafiltration device 410 again.

[0050] A backwashing water pump 405 is connected in parallel on the effluent pipe 404 of the homogeneous filtration device; a chemical cleaning pipe 416 is connected to the water inlet of the precision filter 408, the other end of the chemical cleaning pipe 416 is connected to a chemical cleaning agent storage tank 418, and a chemical cleaning pump 417 is provided on the chemical cleaning pipe 416; an air cleaning pipe 414 is connected to the precision filter effluent pipe 409, and an air compressor pump 415 is connected to the air cleaning pipe 414; to realize the cleaning of the precision filter 408 and the ultrafiltration device 410.

[0051] Homogeneous filtration is completed by a filter chamber, filter plates, air-water dual-purpose filter caps, and homogeneous quartz sand filter media. The filtered water slowly seeps into the upper part of the quartz sand filter layer 402. Through the interception and adsorption of the homogeneous filter media, the suspended solids, colloids, etc. remaining in the water are removed, making the water quality clearer and more transparent, and the effluent turbidity is less than or equal to 1.0 NTU. After the quartz sand filter layer 402 operates for a period of time, a large amount of suspended solids are intercepted in the filter media, the pores between the filter media become smaller, the filtration rate increases, and the treated water volume decreases. At this time, effective flushing must be carried out to restore it. The backwashing procedure is to first perform air washing. Through the friction of air, the suspended solids and exfoliation adhered to the filter media are dispersed, and then water washing is carried out to transport the dispersed suspended solids, colloids, etc. into the regulation tank for re-treatment. Ultrafiltration is a low-pressure membrane separation technology. The filtration process is a pure mechanical screening process driven by the pressure difference on both sides of the membrane, with different rejection rates of substances with different molecular weights in the feed liquid according to the size of the membrane pores. The pressure used in ultrafiltration is usually 0.01 - 0.3 Mpa, the screening pore size is approximately in the range of 0.1 - 0.002 microns, and the molecular weight cut-off is approximately 1000 - 500000 Daltons. The separation mechanism of the ultrafiltration process is mainly the mechanical interception (i.e., screening) of solutes with particle sizes larger than the membrane pores on the membrane surface. Screening is the main mechanism of the ultrafiltration process. Dissolved substances and substances with sizes smaller than the membrane pore size will pass through the ultrafiltration membrane with the permeate, and the substances that cannot pass through will be gradually concentrated in the discharge liquid. Therefore, the produced water (permeate) contains water, ions, and small-molecule substances, while colloidal substances, particles, bacteria, viruses, and protozoa will be removed by the membrane. The ultrafiltration membrane can be reused and can be cleaned with chemical cleaning agents. The effluent of the ultrafiltration device enters the purification water tank and is discharged locally after reaching the Class III standard of the "Surface Water Environment Quality Standard" (GB3838 - 2002). According to the pollution situation of the ultrafiltration membrane operation, a specific cleaning solution with a certain concentration is prepared to remove the pollutants in the ultrafiltration membrane to restore the original characteristics of the membrane. No matter how good the pretreatment is, after long-term use, the membrane surface of the ultrafiltration membrane will still be fouled by scaling. Therefore, a cleaning system is set up in this system. When the membrane module is polluted, chemical cleaning can be carried out.

[0052] In the embodiment, the produced water from three places is used to test the transformed skid-mounted produced water treatment equipment respectively, and the results are as follows:

[0053] 1. The equivalent particle diameter of the produced water from Well No. 42 is 3.2 mm, the sedimentation time is 4.2 minutes, the sedimentation speed is 3.57 mm per second, the sedimentation load is 12.85 cubic meters per square meter per hour, and the effluent turbidity (NTU) is 0.8;

[0054] 2. The equivalent particle diameter of the produced water from Well No. 58 is 3.5 mm, the sedimentation time is 4.0 minutes, the sedimentation speed is 3.75 mm per second, the sedimentation load is 13.5 cubic meters per square meter per hour, and the effluent turbidity (NTU) is 0.6;

[0055] III. For the water extraction and drainage of Well No. 52, the equivalent particle diameter is 3.0 mm, the sedimentation time is 4.3 minutes, the sedimentation velocity is 3.48 mm per second, the sedimentation load is 12.53 cubic meters per square meter per hour, and the effluent turbidity (NTU) is 0.8.

Claims

1. A skid-mounted treatment device for coalbed methane drainage water, comprising a skid-mounted container (7), a coalbed methane drainage water regulating tank (100) and a sludge drying tank (8), wherein the coalbed methane drainage water regulating tank (100) is connected to a coagulation reaction device (102) in the skid-mounted container (7) via a drainage water input pipeline (109), and a lifting water pump (101) is provided on the drainage water input pipeline (109), characterized in that: A drainage water coagulation reaction mechanism (1), a drainage water flocculation reaction mechanism (2), an inclined tube sedimentation mechanism (3), a filtration mechanism (4), an ultrafiltration mechanism (5) and an intelligent control device (6) are respectively arranged in a skid-mounted container (7), and coalbed methane drainage water is arranged in a coalbed methane drainage water regulating tank (100); the feature is that a partition plate (103) is arranged in a coagulation reaction device (102) of the drainage water coagulation reaction mechanism (1), and the partition plate (103) separates the coagulation reaction device The inner cavity of (102) is divided into a coagulation zone (104) and a flocculation zone (105). A two-stage propeller-type coagulation agitator (107) is provided in the coagulation zone (104). In the flocculation zone (105), an upper flocculation mixing and stirring zone (1051) and a lower flocculation discharge zone (1052) are provided from top to bottom. A flocculation agitator (108) is provided in the flocculation zone (105). An upper propeller-type stirring blade (106) is provided on the stirring shaft of the flocculation agitator (108). 081) and a lower frame-type stirring blade (1082), the upper propulsion-type stirring blade (1081) is arranged in the upper flocculation mixing and stirring zone (1051), and the lower frame-type stirring blade (1082) is arranged in the lower flocculation discharge zone (1052); a plug flow zone dividing plate (210) is arranged in the flocculation reaction device (201) of the water discharge flocculation reaction mechanism (2), and the plug flow zone dividing plate (210) divides the inner cavity of the flocculation reaction device (201) into flocculation reaction zones (211) and a flow-pushing zone (212), the flow-pushing zone (212) being a wave-shaped channel; a coagulant dosing pipe (114) is connected to the drainage water input pipeline (109), and the other end of the coagulant dosing pipe (114) is connected to the coagulant dosing device (115); an output port of a flocculant dosing pipe (116) is provided in the upper flocculation mixing and stirring zone (1051), and the other end of the flocculant dosing pipe (116) is connected to the flocculant dosing device (117).

2. The skid-mounted treatment equipment for coalbed methane drainage water according to claim 1, characterized in that: The rotation speed of the two-stage propeller coagulation agitator (107) is 120 revolutions per minute, and the rotation speed of the flocculation agitator (108) is 60 revolutions per minute; the diameter of the upper propeller stirring blade (1081) is twice the diameter of the propeller stirring blade on the two-stage propeller coagulation agitator (107); a flocculation stirring lifting cylinder (202) is provided in the flocculation reaction zone (211), and a water outlet of a coagulation reaction water outlet pipe (111) is provided in the bottom port of the flocculation stirring lifting cylinder (202); the other end of the coagulation reaction water outlet pipe (111) is provided with a flocculation reaction water outlet pipe (111). The coagulation reaction device (102) is arranged at the lower part of the coagulation reaction device (102), and the coagulation reaction device (102) and the flocculation reaction device (201) are connected together through the coagulation reaction outlet pipe (111); a two-stage propulsion paddle type flocculation agitator (203) is arranged in the flocculation stirring and lifting cylinder (202); an inclined sludge input pipe section (207) is connected to the middle pipe wall of the coagulation reaction outlet pipe (111), and the other end of the sludge input pipe section (207) is connected to the sludge return pipe (205) through a sludge return pipe pump (206).

3. The skid-mounted treatment equipment for coalbed methane drainage water according to claim 2, characterized in that: The rotation speed of the two-stage propulsion flocculation agitator (203) is 20-30 revolutions per minute, and the ratio of the diameter of the agitator impeller on the two-stage propulsion flocculation agitator (203) to the diameter of the flocculation agitation lifting cylinder (202) is 2:3; the ratio of the amount of sludge entering the flocculation agitation lifting cylinder (202) through the sludge input pipe section (207) to the amount of water entering the flocculation agitation lifting cylinder (202) through the coagulation reaction outlet pipe (111) is 3-5%.

4. A skid-mounted treatment equipment for coalbed methane drainage water according to claim 1, 2 or 3, characterized in that: An inclined tube clarification zone (302) is arranged at the upper part of the inclined tube sedimentation zone (301) in the inclined tube sedimentation mechanism (3), an inclined tube separation zone (303) is arranged at the middle part of the inclined tube sedimentation zone (301), a sludge sedimentation zone (304) is arranged at the lower part of the inclined tube sedimentation zone (301), a water collection tank (305) is arranged in the inclined tube clarification zone (302), and triangular weir water outlets (306) are arranged at the top ends of the vertical plates on both sides of the water collection tank (305). An inclined tube row (307) is arranged in the inclined tube separation zone (303), and the angle between the inclined tube row (307) and the horizontal plane is 60 degrees; a sludge hopper (308) is arranged in the middle of the sludge settling zone (304), and an electric scraper (309) is arranged on the bottom end surface of the inclined tube settling zone (301) outside the sludge hopper (308); the inclined tube settling zone (301) is connected to the flocculation reaction zone (211) through the overflow outlet (213).

5. The skid-mounted treatment equipment for coalbed methane drainage water according to claim 4, characterized in that: A quartz sand filter layer (402) is provided in the homogeneous filter device (401) of the filter mechanism (4), and an air-water dual-purpose filter cap (403) is provided on the lower bottom surface of the quartz sand filter layer (402). The water inlet of the homogeneous filter device (401) is connected to the water outlet of the water collecting tank (305) in the inclined tube sedimentation area. A homogeneous filter water outlet pipe (404) is connected to the water outlet of the homogeneous filter device (401), and the other end of the homogeneous filter water outlet pipe (404) is connected to the water inlet of the intermediate water tank (406). The intermediate water tank (406) is connected to the water outlet of the homogeneous filter device (401). 06) is connected to a precision filter (408) through an ultrafiltration water pump (407); a precision filter outlet pipe (409) is connected to the output end of the precision filter (408); an ultrafiltration device (410) is connected in series to the precision filter outlet pipe (409); an ultrafiltration device (410) is provided with an outlet pipe (411) of the ultrafiltration device at the output end of the ultrafiltration device (410); the other end of the outlet pipe (411) of the ultrafiltration device is connected to a purified water tank (412); and a discharge water pipe (413) is connected to the purified water tank (412).

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