Coagulation reaction mechanism of skid-mounted treatment equipment for coal bed gas drainage and mining water

Abstract

The utility model discloses a coagulation reaction mechanism of skid-mounted treatment equipment for coal bed gas drainage and production water, which solves the problem of how to construct an efficient coagulation condition for effective precipitation of suspended matters in the coal bed gas drainage and production water. Through a large number of tests and improvements, a push type stirring blade and frame type stirring blade combined form is adopted in an initial flocculation zone, so that generated alumen ustum is large and dense, and the alumen ustum can be easily removed in the subsequent precipitation process; the second stirrer is a combined stirrer, a push type stirrer is arranged at the upper part of the second stirrer, a frame type stirrer is arranged at the lower part of the second stirrer, the second stirrer and the push type stirrer are arranged on the same rotating shaft and rotate simultaneously, the contact area of the frame type stirrer and water is large, the material disturbance quantity is large, and a stirring medium is only sheared and disturbed in the horizontal direction and is not disturbed in the axial direction; therefore, compared with a push type stirring mode, the plate frame type stirring machine has the characteristics of low mixing strength and large quantity of disturbed substances, accords with the rule of particle flocculation, and is beneficial to generating a relatively large alumen ustum prototype.

Description

Technical Field

[0001] The invention relates to water pollution treatment equipment, in particular to a coagulation reactor structure in a skid-mounted equipment for purifying coal bed gas drainage water. Background Art

[0002] At present, the water pollution risks brought by coalbed methane exploitation are becoming increasingly prominent; in the process of coalbed methane exploitation, as the gas from the mined coal seams is extracted, a large amount of drainage water will be discharged from the gas wells. The drainage water contains suspended matter, organic matter, fluoride, petroleum and other pollutants. In particular, the pharmaceutical materials used in coalbed methane drilling and exploitation will also enter the production and drainage water along with 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 the 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, requisition land and equip corresponding water treatment equipment, which has the disadvantages of long construction time and large area. Due to the dispersion of coalbed methane wells and the limited continuous mining time, it is neither economical nor practical to equip the gas wells with fixed ground sewage treatment stations. 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 in coalbed methane drainage water are suspended matter, colloids, macromolecular organic matter and ammonia nitrogen pollution. The drainage water is ink-colored and has poor sensory properties. It is a typical inorganic polluted water. The components of suspended matter are mainly fine particles such as coal dust, rock powder, clay, etc., especially coal powder, whose content is tens to hundreds of milligrams per liter. The suspended matter has small particle size, light specific gravity and slow sedimentation rate. How to use the water treatment method of coagulation → sedimentation → sand filtration → ultrafiltration to remove most of the suspended matter and organic matter from the drainage water? Especially in the coagulation and dosing process of drainage water, how to build an economical and efficient coagulation environment for the effective precipitation of suspended matter has become a problem that needs to be solved on site. Summary of the invention

[0005] The present invention provides a coagulation reaction mechanism of a skid-mounted treatment device for coalbed methane drainage water, which solves the technical problem of how to construct an economical and efficient coagulation condition for the effective precipitation of suspended matter in coalbed methane drainage water.

[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: the conventional coagulation tank and flocculation tank are stirred by a single-stage or multi-stage propeller mixer, which is a kind of stirrer that generates flow by propulsion blades during the stirring process. The peripheral speed of the outer edge of the blade is generally 1.5-2.0 meters per second. The stirred medium moves along the axial direction and the horizontal direction, generating strong shearing and disturbance forces, so that the stirred media are fully mixed. This stirring method has the characteristics of high mixing intensity, intense mixing, and the agent can be fully mixed with water. The disadvantage is that the flocculated alum flowers are easily broken by stirring, affecting the water quality and water volume of the effluent. After a lot of tests and improvements, the present invention has achieved the following results in the initial flocculation. The combination of propeller-type stirring blades and frame-type stirring blades is adopted in the zone, so that the alum flowers produced can be large and dense, making it easy to be removed in the subsequent sedimentation process; the second agitator of the present invention is a combined agitator, with a propeller-type agitator installed on the upper part and a frame-type agitator on the lower part. They are installed on the same rotating shaft and rotate simultaneously. The frame-type agitator has a large contact area with water and a large amount of disturbed materials. The stirring medium only has shear and disturbance in the horizontal direction, but no disturbance in the axial direction. Therefore, compared with the propeller-type agitator, the plate-frame agitator has the characteristics of low mixing intensity and large amount of disturbed materials, which conforms to the law of particle flocculation and is conducive to the production of larger alum flower prototypes.

[0008] A coagulation reaction mechanism of a skid-mounted treatment equipment for coalbed methane drainage water, comprising a coalbed methane drainage water regulating tank and a coagulation reaction device, wherein a lifting water pump and a coalbed methane drainage water inlet pipeline are arranged in the coalbed methane drainage water regulating tank, and a partition plate is arranged in the coagulation reaction device, the partition plate divides the inner cavity of the coagulation reaction device into a coagulation zone and a flocculation zone, a two-stage propeller-type coagulation agitator is arranged in the coagulation zone, an upper flocculation mixing and stirring zone and a lower flocculation discharge zone are arranged from top to bottom in the flocculation zone, a flocculation agitator is arranged in the flocculation zone, an upper propeller-type stirring blade and a lower frame-type stirring blade are arranged on the stirring shaft of the flocculation agitator, and the upper propeller-type stirring blade is arranged in the upper flocculation mixing and stirring zone. In the zone, the lower frame-type stirring blades are arranged in the lower flocculation and discharge zone, a drainage water inlet pipe is connected to the barrel wall of the coagulation reaction device at the lower end of the coagulation zone, the other end of the drainage water inlet pipe is arranged in the coalbed methane drainage water of the coalbed methane drainage water regulating tank, and a water inlet flowmeter is arranged on the drainage water inlet pipe. The water level in the coagulation reaction device is higher than the top of the partition plate, and a flocculation reaction outlet pipe is arranged on the barrel wall at the lower end of the flocculation zone; a coagulant dosing pipe is connected to the drainage water inlet pipe, and the other end of the coagulant dosing pipe is connected to the coagulant dosing device; a water outlet of the 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 the flocculant dosing device.

[0009] The rotational speed of the double-stage propeller 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 propeller type stirring blade is twice that of the propeller type stirring blade on the double-stage propeller type coagulation stirrer.

[0010] The coagulant dosing device includes a stirrer, a tank body and a metering pump. The coagulant in the coagulant dosing device is polyaluminum chloride. After being stirred with water, the coagulant is added to the drainage water inlet pipe in the form of an aqueous solution of the coagulant; the flocculant dosing device includes a stirrer, a tank body and a metering pump. The flocculant in the flocculant dosing device is polyacrylamide. After being stirred with water, the flocculant is added to the upper flocculation mixing and stirring area in the form of an aqueous solution of the flocculant.

[0011] An anti-fluoride agent dosing pipe is connected to the drainage water inlet pipe, and the other end of the anti-fluoride agent dosing pipe is connected to an anti-fluoride agent dosing device.

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

[0013] First step: Turn on the lift water pump to transport the coalbed methane drainage water in the coalbed methane drainage water regulating tank to the coagulation area of the coagulation reaction device. At the same time, start the double-stage propeller type coagulation stirrer and start the coagulant dosing device, and add the aqueous solution of the coagulant to the drainage water inlet pipe through the coagulant dosing pipe. The amount of polyaluminum chloride to be added per ton of coalbed methane drainage water is 10 - 30 grams;

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

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

[0016] Both the upper propeller type stirring blade and the stirring blade of the double-stage propeller type coagulation stirrer are three-piece upward-pushing stirring blades; the diameter of the coagulation reaction device outlet pipe is about 300 millimeters.

[0017] For the suspended solids, colloids, and macromolecular organic matter contained in the drainage water of coalbed methane, which are in a stable state in water and will not precipitate under natural conditions, after adding coagulants in the present invention, through the effects of compression of the double electric layer, electrical neutralization, adsorption bridging, and interception, the suspended solids, colloids, and macromolecular organic matter in the raw water can flocculate, aggregate, and precipitate; by controlling the relationship between the instantaneous flow rate of the treated sewage and the dosage of the drug, and by using a propeller mixer in the upper part, strong shearing and disturbing forces are generated, which can fully mix the drug and water and improve the flocculation effect; a frame mixer is used in the lower part, with only horizontal shearing and disturbance and no axial disturbance, which conforms to the law of particle flocculation and is conducive to the formation of large flocs; and the sewage flow rate and stirring speed are reasonably set, creating a good coagulation environment for the subsequent flocculation of the sewage, which is an important part of the sewage treatment skid-mounted equipment. Brief Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the present invention. Detailed Embodiments

[0019] The present invention will be described in detail below with reference to the accompanying drawings:

[0020] The coagulation reaction mechanism of a skid-mounted treatment device for coalbed methane drainage water 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 inlet pipe 109 is connected to the barrel wall at the lower end of the coagulation zone 104. The other end of the drainage water inlet pipe 109 is arranged in the coalbed methane drainage water in the coalbed methane drainage water regulating tank 100. A drainage water inlet flowmeter 110 is provided on the drainage water inlet pipe 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 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 inlet pipe 109. The other end of the coagulant dosing pipe 114 is communicated with a coagulant dosing device 115; The outlet of a flocculant dosing pipe 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 inlet pipe 109 through the coagulant dosing pipe 114, mixes 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 paddle-type coagulation stirrer 107 to complete the rapid coagulation reaction of the sludge, medicine and raw water, and then enters the flocculation zone 105 through the impeller lifting.

[0021] The rotation speed of the double-stage propulsion type coagulation stirrer 107 is 120 revolutions per minute, and the rotation speed of the flocculation stirrer 108 is 60 revolutions per minute; 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 propulsion paddle type coagulation stirrer 107, so that the coagulant 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 propulsion type stirring blade 1081 is arranged on the upper part of the rotating shaft of the flocculation stirrer 108. Through the rotation of this blade, the water flow and the flocculant are fully stirred and reacted to generate more fine initial forms of flocs. These initial forms of flocs continue to move downward into the lower flocculation and discharge zone 1052, and the further stirring of the 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 paddle blades; arranging the frame type stirring blade at the lower part of the rotating shaft of the flocculation stirrer 108 is to minimize the stirring damage to the further enlarged flocs; generally, the residence time of the produced water in the initial flocculation zone 105 does not exceed 10 minutes, laying a good foundation for subsequent water treatment.

[0022] 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 inlet pipeline 109 in the form of an aqueous solution of the coagulant; 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.

[0023] 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 fluoride removal.

[0024] A working method of the coagulation reaction mechanism of a skid-mounted treatment device for coalbed methane produced water includes the following steps:

[0025] First step, turn on the lift pump 101 to transport the coalbed methane produced water in the coalbed methane produced water regulating pool 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, and add the aqueous solution of the coagulant to the produced water inlet pipeline 109 through the coagulant dosing pipe 114. The amount of coagulant to be added per ton of coalbed methane produced water is 10 - 30 grams;

[0026] 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, start the flocculation stirrer 108 and the flocculant dosing device 117 simultaneously, and add 1-2 grams of flocculant per ton of coalbed methane drainage water;

[0027] 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;

[0028] By controlling the drainage water inlet flowmeter 110, the regulation of the water inflow of the coagulation reaction device 102 can be achieved, and by regulating the rotation speeds of the double-stage propeller coagulation stirrer 107 and the flocculation stirrer 108 respectively, the residence time of the drainage water passing through the coagulation zone 104 and the initial flocculation zone 105 can be realized, and a better coagulation effect can be explored.

Claims

1. A coagulation reaction mechanism of a skid-mounted treatment device for coalbed methane drainage water, comprising a coalbed methane drainage water regulating tank (100) and a coagulation reaction device (102), wherein a lifting water pump (101) and a coalbed methane drainage water inlet pipeline (109) are arranged in the coalbed methane drainage water regulating tank (100), characterized in that: A partition plate (103) is provided in the coagulation reaction device (102), and 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 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 coagulation zone (105), and an upper propulsion agitator blade (1081) and a lower frame agitator blade (1082) are provided on the agitation shaft of the flocculation agitator (108), the upper propulsion agitator blade (1081) is provided in the upper flocculation mixing agitation zone (1051), the lower frame agitator blade (1082) is provided in the lower flocculation discharge zone (1052), and the upper propulsion agitator blade (1081) is provided in the upper flocculation mixing agitation zone (1051), and the lower frame agitator blade (1082) is provided in the lower flocculation discharge zone (1052). ) is connected to a water inlet pipe (109) on the barrel wall of the coagulation reaction device at the lower end, the other end of the water inlet pipe (109) is arranged in the coalbed methane water of the coalbed methane water regulating tank (100), and a water inlet flow meter (110) is arranged on the water inlet pipe (109). The water level (106) in the coagulation reaction device (102) is higher than the top of the partition plate (103), and the water level (110) on the barrel wall at the lower end of the flocculation zone (105) is higher than the top of the partition plate (103). A flocculation reaction water outlet pipe (111) is provided; a coagulant dosing pipe (114) is connected to the drainage water inlet pipe (109), and the other end of the coagulant dosing pipe (114) is connected to a coagulant dosing device (115); a water outlet 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 flocculation reaction mechanism of 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 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).

3. The coagulation reaction mechanism of the skid-mounted treatment equipment for coalbed methane drainage water according to claim 1 or 2, characterized in that: The coagulant dosing device (115) comprises an agitator, a tank body and a metering pump. The coagulant in the coagulant dosing device (115) is polyaluminium chloride. After the coagulant is stirred by adding water, it is added to the drainage water inlet pipeline (109) in the form of a coagulant aqueous solution. The flocculant dosing device (117) comprises an agitator, a tank body and a metering pump. The flocculant in the flocculant dosing device (117) is polyacrylamide. After the flocculant is stirred by adding water, it is added to the upper flocculation mixing and stirring zone (1051) in the form of a flocculant aqueous solution.

4. The coagulation reaction mechanism of the skid-mounted treatment equipment for coalbed methane drainage water according to claim 1 or 2, characterized in that: A defluorinating agent dosing pipe (112) is connected to the drainage water inlet pipe (109), and a defluorinating agent dosing device (113) is connected to the other end of the defluorinating agent dosing pipe (112).

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