Flocculation reaction mechanism in skid-mounted treatment equipment for coal bed gas drainage and mining water

Abstract

The utility model discloses a flocculation reaction mechanism in skid-mounted treatment equipment for coal bed gas drainage and mining water, which increases the probability of particle collision for a high-concentration suspended sludge layer and constructs an optimized flocculation reaction environment. Sludge accounting for 3-5% of the water is conveyed into a flocculation stirring lifting cylinder (202) through an inclined sludge input pipe section (207); drainage water and sludge with alumen ustum in the flocculation stirring lifting cylinder are mixed under the stirring of the two-stage propeller type flocculation stirrer (203) at the speed of 20-30 revolutions per minute to generate a flocculating constituent, and the flocculating constituent overflows from the upper port of the flocculation stirring lifting cylinder (202) under the action of a propeller blade and then falls to the bottom of the flocculation reaction barrel (201). Most of the floccules at the bottom enter the flow pushing channel (212) through the water flow transition outlet (204); the maximum flocculation of the sewage is realized.

Description

Technical Field

[0001] The present invention relates to water pollution treatment equipment, in particular to a flocculation reaction mechanism and a working method of a skid-mounted treatment equipment for coalbed methane drainage water. Background Art

[0002] At present, the water pollution risks brought by coalbed methane mining are becoming increasingly prominent. During the coalbed methane mining process, as the mined coal seam gas is extracted, a large amount of drainage water will be discharged from the gas well. The drainage water contains suspended matter, organic matter, fluoride, petroleum and other pollutants. In particular, the pharmaceutical materials used in coalbed methane drilling and mining will also enter the drainage water during the mining process, 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 must be treated to remove pollutants in the water. The treated drainage water is generally discharged on-site into surface rivers. Therefore, the pollution treatment of coalbed methane drainage water has become a top priority for local society and production enterprises.

[0003] For the treatment of coalbed methane drainage water, if it is treated in the same way as traditional industrial wastewater, it is necessary to build a ground sewage treatment station, acquire land and equip corresponding water treatment equipment, which has the disadvantages of long construction time and large area occupation; 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 wells; how to design a movable integrated drainage water treatment equipment that can be easily moved according to the on-site conditions has become an urgent requirement for coalbed methane drainage water treatment.

[0004] The main pollutants contained in coalbed methane drainage water are suspended solids, colloids, large molecular organic matter and ammonia nitrogen pollutants. The water treatment method of coagulation → sedimentation → sand filtration → ultrafiltration is generally used to remove most of the suspended solids and organic matter. Coagulation is the first step in polluted water treatment. A flocculation zone is generally set up after the coagulation zone. The flocculation reaction zone is also called the slow mixing zone. The stirring speed of the mixed water after dosing is controlled by an adjustable speed mixer to promote the growth of alum flocs in the water and make the alum flocs dense and uniform. In the flocculation reaction zone, the coalbed methane drainage wastewater, under the action of the coagulant aid (PAM), forms a high-concentration suspended sludge layer to increase the collision opportunity of particles and effectively adsorb pollutants such as colloids, suspended solids, emulsified oil, COD and metal ions. In the water treatment process, how to save the dosage of chemicals and maintain the suspended solids concentration in the reaction zone at an optimal level to achieve the purpose of optimizing the flocculation reaction has become a topic that needs to be studied in the flocculation reaction zone. Summary of the Invention

[0005] The present invention provides a flocculation reaction mechanism in a skid-mounted treatment device for coalbed methane drainage water, which increases the chances of particle collision in a high-concentration suspended sludge layer and constructs an optimized flocculation reaction environment.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The overall concept of the present invention is as follows: flocculation is to disturb the water body through hydraulic stirring or mechanical stirring to generate velocity gradient or vortex, so as to promote the collision and aggregation of medium particles; according to different energy sources, it is divided into hydraulic flocculation tank and mechanical flocculation tank; the traditional process is that after the mechanical stirring flocculation reaction tank, the treated water flows to the inclined tube sedimentation tank in a laminar flow mode, so that the alum flocs do not break and the alum flocs are removed in the inclined tube sedimentation tank; after a large number of tests and improvements, 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, promoting the collision of particles, causing the alum flocs to continue to grow, and making them easier to remove in the inclined tube sedimentation tank.

[0008] A flocculation reaction mechanism in a skid-mounted treatment device for coalbed methane drainage and production, comprising a flocculation reaction device, a plug flow zone partition plate provided in the flocculation reaction device, the plug flow zone partition plate dividing the inner cavity of the flocculation reaction device into a flocculation reaction zone and a plug flow zone, a water flow transition outlet from the flocculation reaction zone to the plug flow zone provided below the plug flow zone partition plate, a flooding outlet from the plug flow zone to the inclined tube sedimentation zone provided at the upper end of the plug flow zone; a flocculation stirring and lifting cylinder provided in the flocculation reaction zone, a flocculation stirring and lifting cylinder provided at the bottom of the flocculation stirring and lifting cylinder The port is provided with an outlet pipe of a coagulation reaction outlet pipe, and the other end of the coagulation reaction outlet pipe is provided 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 outlet pipe; a two-stage propeller-type flocculation agitator is provided in the flocculation stirring and lifting cylinder; an inclined sludge input pipe section is connected to the middle pipe wall of the coagulation reaction outlet pipe, and the other end of the sludge input pipe section is connected to the sludge return pipe through a sludge return pipe pump; the plug flow area is a wavy channel.

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

[0010] The push flow area is a wavy channel which is achieved by arranging a zigzag plate in the channel; a disinfectant dosing pipe is connected to the coagulation reaction water outlet pipe, and a disinfectant dosing device is connected to the other end of the disinfectant dosing pipe.

[0011] A method for operating a flocculation reaction mechanism of a skid-mounted treatment device for coalbed methane drainage water, characterized by comprising the following steps:

[0012] The first step is to start the sludge return pipeline pump according to the amount of water from the coagulation reaction device, and transport 3-5% of the sludge of the water intake through the inclined sludge input pipe section to the flocculation stirring lifting cylinder;

[0013] In the second step, the drainage water and sludge in the flocculation stirring and lifting cylinder with alum flowers are mixed and formed into flocs under the stirring of the double-stage propeller flocculation stirrer at 20-30 revolutions per minute. The flocs overflow from the upper port of the flocculation stirring and lifting cylinder under the action of the propeller blades and fall to the bottom of the flocculation reaction device. Most of the flocs at the bottom enter the propulsion zone through the water transition outlet, and a part of the flocs at the bottom return to the flocculation stirring and lifting cylinder through the lower port of the flocculation stirring and lifting cylinder.

[0014] In the third step, the flocs entering the push flow area are repeatedly squeezed and contracted by the wavy channel, making the flocs denser. Finally, they flow through the overflow channel into the inclined tube sedimentation area with the water flow.

[0015] The drainage water of the present invention first enters the coagulation reaction zone, and the coagulant (PAC) is fully mixed with the coalbed methane drainage water. The hydrolysis product of the coagulant compresses the double electric layer of the colloidal particles, so that the colloidal particles are destabilized and agglomerated to form fine alum flocs. Then the flocculant (PAM) is added, and the flocculant further promotes the small flocs entering to form larger flocs through adsorption, electrical neutralization, mutual bridging, complexation, and adsorption. Under the action of the slow stirrer, the agent and the flocs are fully mixed. Then, the water enters the flocculation stirring and lifting cylinder, reacts with the sludge returned by the sludge return pipe pump, accelerates the formation of large flocs, and aggregates the particulate matter in the water. The present invention has explored the proportional relationship between the flow rate entering the flocculation reaction zone and the sludge flow rate returned by the sludge return pipe pump through multiple experiments, thereby achieving the maximum flocculation of the sewage. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings:

[0018] A flocculation reaction mechanism in a skid-mounted treatment device for coalbed methane drainage water includes a flocculation reaction device 201. A flow-pushing zone dividing plate 210 is provided in the flocculation reaction device 201. The flow-pushing zone dividing 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 flocculation reaction zone 211 is used to adsorb pollutants such as suspended matter and colloids onto flocs, and the flow-pushing zone 212 is used to transport large flocs. A water flow transition outlet 204 from the flocculation reaction zone 211 to the flow-pushing zone 212 is provided below the flow-pushing zone dividing plate 210. The upper end is provided with an overflow outlet 213 from the plug flow area 212 to the inclined tube sedimentation area; a flocculation stirring and lifting cylinder 202 is provided in the flocculation reaction area 211, and the outlet of the coagulation reaction outlet pipe 111 is provided in the bottom port of the flocculation stirring and lifting cylinder 202, and the other end of the coagulation reaction outlet pipe 111 is provided 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 propeller flocculation agitator 203 is provided in the flocculation stirring and lifting cylinder 202; in the middle of the coagulation reaction outlet pipe 111 On the wall of the pipe, there is an inclined sludge input pipe section 207, and the other end of the sludge input pipe section 207 is connected to the sludge return pipe 205 through the sludge return pipe pump 206; the push flow area 212 is a wave-shaped channel; the drainage water from the coagulation area first passes through the coagulation reaction outlet pipe 111 into the lower end of the flocculation stirring and lifting cylinder 202, and then, under the push of the blades of the double-stage propeller flocculation stirrer 203, moves upward in the flocculation stirring and lifting cylinder 202, overflows from the upper port of the flocculation stirring and lifting cylinder 202, and falls to the bottom of the flocculation reaction zone 211, and then enters the water transition outlet 204. The sludge is returned to the push flow area 212, rises along the push flow area 212 to the overflow outlet 213, and finally overflows into the inclined tube sedimentation area; the sludge return is extracted and returned from the mud bucket of the inclined tube sedimentation area by the sludge return pipeline pump 206. The sludge in the sedimentation tank has certain coagulation properties. The return of the sludge increases the suspended matter in the drainage water and forms a sludge layer of flocculent body to a certain extent. The return sludge particles can increase the sedimentation rate of the flocculent body. At the same time, the flocculation and adsorption effect of the biological flocculent body in the sludge can greatly improve the removal rate of pollutants, play a role in strengthening the effect of primary treatment, and avoid excessive addition of chemicals.

[0019] The rotation speed of the two-stage propeller flocculation agitator 203 is 20-30 revolutions per minute, and the ratio of the diameter of the stirring impeller on the two-stage propeller flocculation agitator 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 outlet pipe 111 is 3-5%.

[0020] The flow-pushing zone 212 is a wavy channel realized by setting a corrugated plate in the channel; a disinfectant dosing pipe 208 is connected to the coagulation reaction outlet pipe 111, and a disinfectant dosing device 209 is connected to the other end of the disinfectant dosing pipe 208 to realize the disinfection of the drainage water.

[0021] A method for operating a flocculation reaction mechanism of a skid-mounted treatment device for coalbed methane drainage water comprises the following steps:

[0022] The first step is to start the sludge return pipe pump 206 according to the amount of water from the coagulation reaction device 102, and transport 3-5% of the sludge of the water intake through the inclined sludge input pipe section 207 to the flocculation stirring lifting cylinder 202;

[0023] In the second step, the drainage water and sludge in the flocculation stirring and lifting cylinder with alum flowers are mixed and formed into flocs under the stirring of the double-stage propeller flocculation stirrer 203 at 20-30 revolutions per minute. The flocs overflow from the upper port of the flocculation stirring and lifting cylinder 202 under the action of the propeller blades and fall to the bottom of the flocculation reaction zone 211. Most of the flocs at the bottom enter the push flow zone 212 through the water flow transition outlet 204, and a part of the flocs at the bottom return to the flocculation stirring and lifting cylinder 202 through the lower port of the flocculation stirring and lifting cylinder 202.

[0024] In the third step, the flocs entering the push flow area 212 are squeezed and compressed repeatedly by the wavy channel, making the flocs more compact. Finally, they flow through the overflow channel 213 into the inclined tube sedimentation area.

[0025] The embodiment used drainage water from three locations to test the modified skid-mounted drainage water treatment equipment. The results are as follows:

[0026] 1. The equivalent particle diameter of the wastewater from Well No. 42 is 3.2 mm, the sedimentation time is 4.2 minutes, the sedimentation rate 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;

[0027] 2. The equivalent particle diameter of the drainage water from Well 58 is 3.5 mm, the sedimentation time is 4.0 minutes, the sedimentation rate 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;

[0028] 3. The equivalent particle diameter of the wastewater produced from Well No. 52 is 3.0 mm, the sedimentation time is 4.3 minutes, the sedimentation rate 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 flocculation reaction mechanism in a skid-mounted treatment device for coalbed methane drainage water, comprising a flocculation reaction device (201), wherein a flow-pushing zone dividing plate (210) is provided in the flocculation reaction device (201), the flow-pushing zone dividing plate (210) dividing the inner cavity of the flocculation reaction device (201) into a flocculation reaction zone (211) and a flow-pushing zone (212), a water flow transition outlet (204) from the flocculation reaction zone (211) to the flow-pushing zone (212) is provided below the flow-pushing zone dividing plate (210), and a flooding outlet (213) from the flow-pushing zone (212) to the inclined tube sedimentation zone is provided at the upper end of the flow-pushing zone (212); characterized in that: A flocculation stirring and lifting cylinder (202) is provided in the flocculation reaction zone (211), and a water outlet of a coagulation reaction outlet pipe (111) is provided in the bottom port of the flocculation stirring and lifting cylinder (202). The other end of the coagulation reaction outlet pipe (111) is provided 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 propeller-type flocculation agitator (203) is provided 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); the push flow zone (212) is a wave-shaped channel.

2. The flocculation reaction mechanism in the skid-mounted treatment equipment for coalbed methane drainage water according to claim 1 is 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 stirring 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%.

3. The flocculation reaction mechanism in the skid-mounted treatment equipment for coalbed methane drainage water according to claim 1 or 2, characterized in that: The push flow area (212) is a wavy channel realized by arranging a zigzag plate 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).

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