A raw coal gas scrubbing tower for water coal slurry gasification

Abstract

The present invention relates to a raw coal gas scrubbing tower for water coal slurry gasification, which is composed of a tower body, a cyclone plate demister, a tray, a Venturi scrubber, a distributor, a gas guide pipe, etc. The raw coal gas enters the built-in Venturi scrubber through the gas guide pipe. The raw coal gas contacts the swirling spray water in the Venturi scrubber at the Venturi throat. The solid particles in the raw coal gas become humid and heavier and then enter the distributor, where solid-gas separation is carried out. The raw coal gas continues to rise through the tray and is washed again by the washing water on the tray. After being collided by the cyclone plate demister, the humidified fine ash and water are removed, and the clean water gas flows out from the top of the scrubbing tower and enters the subsequent process section. The present invention effectively solves the problem that the nozzles, throats and distributors of conventional Venturi scrubbers are prone to blockage. The structure is simple and reasonable, with less investment, and can be widely applied to the scrubbing process of raw coal gas, especially suitable for the preliminary scrubbing and purification process of raw coal gas generated by entrained flow bed water coal slurry gasification.

Description

Technical Field

[0001] The present invention belongs to the technical field of gasification in chemical production, and particularly relates to a raw coal gas scrubbing tower for water-coal slurry gasification. Background Art

[0002] As is well known, "lack of oil, rich in coal, and short of gas" is the basic characteristic of China's energy structure. With the rapid economic development and deepening reform, under the energy pattern of lack of oil and rich in coal, developing coal chemical industry to replace petrochemical products has become a transformation strategy to resolve the shortage of oil. Coal gasification is the core of clean and efficient conversion of coal and the basis for developing coal chemical products. The coal gas produced by coal gasification can be used for the production of electricity, synthetic oil, coal-based chemicals, hydrogen, etc. However, the production of these products has strict requirements on the quality of coal gas. Therefore, in order to meet the needs of downstream processes, it is necessary and inevitable to wash and purify the raw coal gas.

[0003] Chinese Patent CN204417444U proposed a gasification scrubbing tower. This utility model discloses a gasification scrubbing tower, which includes a tower body, a cyclone separator, a tray, a Venturi inlet pipe, a makeup water pipe, and an annular water distribution pipe. The top of the tower body is provided with a water gas outlet. An upper part inside the tower body is provided with a cyclone separator. Three trays are arranged downward in sequence below the cyclone separator. A washing liquid inlet is provided on the tower body wall between the cyclone separator and the first tray. A Venturi inlet pipe and a makeup water pipe are provided below the last tray. The nozzle of the makeup water pipe is fixedly communicated with the inlet of the annular water distribution pipe arranged inside the tower body. The annular water distribution pipe is fixedly arranged along the inner wall of the tower body. A water distribution pipe support groove is provided on the inner wall of the tower body. A plurality of water outlets are evenly arranged on the bottom pipe wall of the water distribution pipe. The advantage of this utility model is that the supplemented water can uniformly enter the inside of the scrubbing tower through the annular water distribution pipe and fully contact with the gas, achieving a better gas scrubbing effect. The supplemented water will not stir the liquid level below in the scrubbing tower, so that the solid particles washed down can effectively settle to the bottom.

[0004] Chinese Patent CN108441266A discloses a washing and dust removal device for syngas and its washing and dust removal process. The device includes: a quench chamber of a gasifier, which is used for washing and cooling the raw syngas to obtain preliminarily purified syngas, molten slag, and black water; a Venturi scrubber, which is an external type and is used for wetting and dust capture of the preliminarily purified syngas to form dust-containing liquid droplets; a separation scrubbing tower, whose inner cavity is divided into an upper inner cavity and a lower inner cavity. The lower inner cavity receives the syngas with dust-containing liquid droplets for gas-liquid separation. A syngas diversion structure is provided between the upper inner cavity and the lower inner cavity. The upper inner cavity is used for washing the syngas entering it to remove residual fine particles and obtaining purified syngas and sewage; a quench water pump is used to circulate the upper clear liquid to the quench chamber of the gasifier and the Venturi scrubber. The present invention can obtain syngas with excellent dust removal effect by using equipment with a small number and small resistance loss, and at the same time can improve the washing efficiency.

[0005] Chinese Patent CN207031371U proposes a syngas wetting and washing system, and the syngas wetting and washing system includes a syngas scrubbing tower, a Venturi scrubber, a quench water pump, and a Venturi water pump. By setting a liquid collection tank with a gas guide pipe in the scrubbing tower, adding internal components to strengthen liquid-solid separation, and changing the flow path, contact mode, and residence time of the solid-containing wet syngas in the tower, the washing effect of the syngas is improved.

[0006] Through the analysis of the prior art, scrubbing towers are used as the scrubbing equipment for raw coal gas in current coal gasification technologies, and its importance is self-evident. However, the internal structure of the scrubber determines the scrubbing effect of the raw coal gas. The internal structures of the scrubbing towers used in the furnace types represented by Texaco, Aerospace Furnace, and Tsinghua Furnace are all downcomers, distributors, trays, and demisters. For such structures, a Venturi scrubber is installed before the raw coal gas enters the scrubbing tower, and the supernatant of the scrubbing tower is generally used as the humidifying and dust-removing water for the Venturi. In some cases, a separate scrubbing tower is used for dust removal and scrubbing purification at the upper end and gas-liquid separation at the lower end.

[0007] Although there are many current technologies for scrubbing raw coal gas, there are still some deficiencies and drawbacks: (1) The solid content in the supernatant of the scrubbing tower ash water is relatively high, which easily causes blockage of the Venturi scrubbing nozzles, resulting in a decline in the scrubbing effect during long-term operation, serious ash carryover in the raw coal gas, and inability to continue the subsequent processes. (2) Due to the presence of the water spray pipe at the Venturi throat, the resistance of the raw coal gas passing through the Venturi is increased, and the entrained dust condenses to cause blockage of the throat, blockage of the syngas pipeline, high pressure difference between the gasifier and the scrubbing tower system, and high pressure in the gasifier combustion chamber. (3) Due to serious ash carryover in the raw coal gas, the distributor of the scrubbing tower is severely blocked, the pressure difference of the scrubbing tower increases, which is not conducive to the long-term operation of the gasifier, and it is difficult to dredge the distributor during shutdown and maintenance. (4) The solid content and steam-gas ratio of the raw coal gas at the outlet of the scrubbing tower are high, which cannot meet the requirements of the subsequent processes, and the equipment needs to be frequently overhauled. (5) The external Venturi has a high pressure rating, special materials, high cost, complex process, and large floor area. Summary of the Invention

[0008] To solve the above problems, the present invention provides a water coal slurry gasification raw coal gas scrubbing tower with simple equipment, low cost, good scrubbing effect, and stable operation.

[0009] The technical solution of the present invention is as follows: A water coal slurry gasification raw coal gas scrubbing tower, comprising a tower body, with a water coal gas outlet provided at the top of the tower body; inside the tower body, a cyclone plate demister, a tray, a Venturi scrubber, and a distributor are successively arranged from top to bottom; a tray washing water inlet is provided on the tower body wall between the cyclone plate demister and the tray; a Venturi raw coal gas inlet, a Venturi spray water inlet, a Venturi flushing water outlet, and a high-pressure ash water inlet are successively arranged from top to bottom on the tower body wall between the tray and the distributor; a scrubbing tower black water outlet is provided on the tower body wall below the distributor; the Venturi raw coal gas inlet is connected to the Venturi scrubber through a gas guide pipe; the Venturi scrubber is vertically installed, and the lower end is connected to the distributor through a distributor inlet pipe, and the distributor is fixed on the scrubbing tower wall through a support groove.

[0010] In the water coal slurry gasification raw coal gas scrubbing tower described above, a water jacket is provided on the outer side of the throat of the Venturi scrubber, and a number of spray holes evenly distributed along the circumference are provided on the throat of the Venturi scrubber; the condensate sent from the later stage is used as the Venturi washing water and enters the water jacket tangentially from the Venturi spray water inlet. The spray water swirls in the water jacket and sprays out from the spray holes, contacts the raw coal gas at the throat of the Venturi scrubber, and the humidified raw coal gas enters the distributor under the action of pressure difference and gravity. When the water jacket scales during long-term operation of the system, the water can be discharged through the Venturi flushing water outlet to flush the water jacket, effectively solving the problem that the water jacket of the Venturi scrubber is easily blocked, and it can operate for a long time without disassembling the Venturi scrubber for maintenance and cleaning.

[0011] In the water coal slurry gasification raw coal gas scrubbing tower described above, the material of the Venturi scrubber is 316L stainless steel.

[0012] In the water coal slurry gasification raw coal gas scrubbing tower described above, the diameter of the spray holes of the Venturi scrubber is 5 - 10 mm.

[0013] In the water coal slurry gasification raw coal gas scrubbing tower described above, the included angle between the center line of the spray holes of the Venturi scrubber and the axis of the throat of the Venturi scrubber is 20° - 40°.

[0014] For the above-mentioned raw coal gas scrubbing tower for water coal slurry gasification, the distributor is provided with a main pipe, and a slag discharge pipe is arranged at the bottom of the main pipe. Larger solid particles in the raw coal gas can be introduced into the bottom of the scrubbing tower through the slag discharge pipe to prevent the solid particles from agitating the water bath; several branch pipes are arranged on both sides of the main pipe of the distributor, and slag discharge holes are arranged at the bottom of each branch pipe to prevent the distributor from being blocked and extend the service life of the equipment; two exhaust holes are arranged on both the main pipe and the branch pipes of the distributor; the solid particles in the raw coal gas enter the water bath through the slag discharge pipe of the main pipe of the distributor and the slag discharge holes of the branch pipes of the distributor, and flow out of the scrubbing tower from the black water outlet of the scrubbing tower; the gas phase part flows out from the exhaust holes of the main pipe and the branch pipes of the distributor, reaches the tray after passing through the water bath, contacts the condensate at the tray washing water inlet on the tray, and after humidifying and cooling, most of the fine ash overflows into the water bath along with the tray washing water. When the gas phase continues to rise and encounters the cyclone demister, the liquid with reduced kinetic energy and a small amount of fine ash fall on the tray under the action of gravity, and the clean water gas enters the subsequent section from the water gas outlet at the top of the scrubbing tower. Finally, the solid content of the water gas exiting the top of the scrubbing tower is ≤ 0.8 mg / Nm 3 .

[0015] For the above-mentioned raw coal gas scrubbing tower for water coal slurry gasification, the diameter of the slag discharge pipe at the bottom of the main pipe of the distributor is 400 - 600 mm.

[0016] For the above-mentioned raw coal gas scrubbing tower for water coal slurry gasification, the slag discharge holes at the bottom of the branch pipes of the distributor are long strip holes.

[0017] For the above-mentioned raw coal gas scrubbing tower for water coal slurry gasification, the width of the slag discharge holes at the bottom of the branch pipes of the distributor is 10 - 20 mm.

[0018] For the above-mentioned raw coal gas scrubbing tower for water coal slurry gasification, the length of the slag discharge holes at the bottom of the branch pipes of the distributor is 150 - 200 mm.

[0019] For the above-mentioned raw coal gas scrubbing tower for water coal slurry gasification, the exhaust holes of the main pipe of the distributor are arranged in the direction with an angle of 40° - 70° to the axis of the main pipe of the distributor.

[0020] For the above-mentioned raw coal gas scrubbing tower for water coal slurry gasification, the exhaust holes of the branch pipes of the distributor are arranged in the direction with an angle of 40° - 70° to the axis of the branch pipes of the distributor.

[0021] The beneficial effects of the present invention are as follows: (1) The swirl flow design of the Venturi scrubber effectively solves the problem that the nozzles and throat pipes of conventional Venturi scrubbers are prone to blockage, and it can operate for a long time without being disassembled for inspection and cleaning. (2) The distributor is provided with slag discharge pipes and long strip-shaped slag discharge holes, which effectively prevent the distributor from being blocked and extend the operation cycle. (3) The improved Venturi scrubber is used in combination with the distributor, eliminating the hidden danger of high pressure difference in the gasifier and scrubber systems, reducing the solid content of the water gas at the outlet of the scrubber, extending the service life of the equipment, and providing a strong guarantee for the stable operation of the subsequent process section. (4) The Venturi scrubber is installed internally, simplifying the production process, occupying a small area, and saving production costs. (5) Online cleaning of the Venturi is achieved, avoiding disassembly and inspection of the Venturi, and reducing the labor intensity of maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a sectional view of the Venturi scrubber in the present invention; Figure 3 is a sectional view taken along line A-A of the Venturi scrubber in the present invention; Figure 4 is a top view of the distributor in the present invention; Figure 5 is a sectional view taken along line B-B of the distributor in the present invention.

[0023] Figures 1-5 In the figure, 1 is the water gas outlet, 2 is the cyclone demister, 3 is the inlet of tray washing water, 4 is the tray, 5 is the inlet of Venturi spray water, 6 is the thick gas guide pipe, 7 is the Venturi scrubber, 8 is the inlet of high-pressure ash water, 9 is the distributor, 10 is the main distributor slag discharge pipe, 11 is the tower body, 12 is the outlet Ⅰ of scrubber black water, 13 is the skirt support, 14 is the outlet Ⅱ of scrubber black water, 15 is the support groove, 16 is the inlet pipe of the distributor, 17 is the outlet of Venturi flushing water, 18 is the inlet of Venturi thick gas, 19 is the water jacket, 20 is the Venturi spray hole, 21 is the main distributor pipe, 22 is the distributor branch pipe, 23 is the series Ⅰ of main distributor outlet air holes, 24 is the series Ⅱ of main distributor outlet air holes, 25 is the distributor branch pipe slag discharge hole, 26 is the series Ⅰ of distributor branch pipe outlet air holes, 27 is the series Ⅱ of distributor branch pipe outlet air holes. DETAILED DESCRIPTION OF THE INVENTION

[0024] Refer to the attached Figures 1-5In this embodiment, it includes a tower body 11, and a water gas outlet 1 is provided at the top of the tower body; inside the tower body, a cyclone plate demister 2, a tray 4, a Venturi scrubber 7, and a distributor 9 are successively arranged from top to bottom; a tray washing water inlet 3 is provided on the tower body wall between the cyclone plate demister 2 and the tray 4; a Venturi raw gas inlet 18, a Venturi spray water inlet 5, a Venturi flushing water outlet 17, and a high-pressure ash water inlet 8 are successively arranged from top to bottom on the tower body wall between the tray 4 and the distributor 9; a scrubber black water outlet I 12 and a scrubber black water outlet II 14 are provided on the tower body wall below the distributor; the Venturi raw gas inlet 18 is connected to the Venturi scrubber 7 through a gas guide pipe 6; the Venturi scrubber 7 is vertically installed, and the lower end is connected to the distributor 9 through a distributor inlet pipe 16, and the distributor 9 is fixed on the scrubber tower wall through a support groove 15.

[0025] The difference in another embodiment is that a water jacket 19 is provided on the outer side of the throat of the Venturi scrubber, and a number of spray holes 20 are evenly distributed along the circumference on the throat of the Venturi scrubber; the condensate sent from the later process section is used as the Venturi washing water, and enters the water jacket 19 tangentially from the Venturi spray water inlet 5. The spray water swirls in the water jacket 19 and sprays out from the spray holes 20, contacts the raw gas at the throat of the Venturi scrubber, and the humidified raw gas enters the distributor 9 under the action of pressure difference and gravity. When the water jacket 19 is scaled during the long-term operation of the system, the water can be discharged through the Venturi flushing water outlet 17 to flush the water jacket 19, effectively solving the problem that the water jacket 19 of the Venturi scrubber is easily blocked, and it can operate for a long time without disassembling, overhauling and cleaning the Venturi scrubber.

[0026] The difference in another embodiment is that the material of the Venturi scrubber is 316L stainless steel.

[0027] The difference in another embodiment is that the diameter of the spray holes of the Venturi scrubber is 5 mm.

[0028] The difference in another embodiment is that the diameter of the spray holes of the Venturi scrubber is 6 mm.

[0029] The difference in another embodiment is that the diameter of the spray holes of the Venturi scrubber is 7 mm.

[0030] The difference in another embodiment is that the diameter of the spray holes of the Venturi scrubber is 8 mm.

[0031] The difference in another embodiment is that the diameter of the spray holes of the Venturi scrubber is 9 mm.

[0032] The difference in another embodiment is that the diameter of the spray holes of the Venturi scrubber is 10 mm.

[0033] The difference in another embodiment is that the included angle between the center line of the spray holes of the Venturi scrubber and the axis of the Venturi scrubber throat is 20°.

[0034] Another embodiment is different in that the included angle between the central line of the spray holes of the Venturi scrubber and the axis of the throat of the Venturi scrubber is 25°.

[0035] Another embodiment is different in that the included angle between the central line of the spray holes of the Venturi scrubber and the axis of the throat of the Venturi scrubber is 30°.

[0036] Another embodiment is different in that the included angle between the central line of the spray holes of the Venturi scrubber and the axis of the throat of the Venturi scrubber is 35°.

[0037] Another embodiment is different in that the included angle between the central line of the spray holes of the Venturi scrubber and the axis of the throat of the Venturi scrubber is 40°.

[0038] Another embodiment is different in that the distributor 9 is provided with a main pipe 21, a slag discharge pipe 10 is provided at the bottom of the main pipe, larger solid particles in the raw coal gas can be introduced into the bottom of the scrubbing tower through the slag discharge pipe 10 to prevent the solid particles from agitating the water bath; a number of branch pipes 22 are provided on both sides of the main pipe of the distributor, and slag discharge holes 25 are provided at the bottoms of the branch pipes to prevent the distributor from being blocked and extend the service life of the equipment; two gas outlet holes are provided on both the main pipe and the branch pipes of the distributor; the solid particles in the raw coal gas enter the water bath through the slag discharge pipe 10 of the main pipe of the distributor and the slag discharge holes 25 of the branch pipes of the distributor, and flow out of the scrubbing tower from the black water outlet Ⅰ12 or the black water outlet Ⅱ14 of the scrubbing tower; the gas phase part flows out from the gas outlet holes of the main pipe and the branch pipes of the distributor, reaches the tray 4 after passing through the water bath, contacts the condensate of the tray washing water inlet 3 on the tray, after being humidified and cooled, most of the fine ash overflows into the water bath along with the tray washing water, when the gas phase continues to rise and encounters the cyclone plate demister 2, the liquid with lost kinetic energy and a small part of the fine ash fall on the tray 4 under the action of gravity, and the clean water gas enters the subsequent section from the water gas outlet 1 at the top of the scrubbing tower. Finally, the solid content of the water gas exiting the top of the scrubbing tower is ≤0.8mg / Nm 3 。

[0039] Another embodiment is different in that the diameter of the slag discharge pipe at the bottom of the main pipe of the distributor is 400mm.

[0040] Another embodiment is different in that the diameter of the slag discharge pipe at the bottom of the main pipe of the distributor is 500mm.

[0041] Another embodiment is different in that the diameter of the slag discharge pipe at the bottom of the main pipe of the distributor is 600mm.

[0042] Another embodiment is different in that the slag discharge holes at the bottoms of the branch pipes of the distributor are long strip holes.

[0043] Another embodiment is different in that the width of the slag discharge holes at the bottoms of the branch pipes of the distributor is 10mm.

[0044] Another embodiment is different in that the width of the slag discharge hole at the bottom of the distributor branch pipe is 15 mm.

[0045] Another embodiment is different in that the width of the slag discharge hole at the bottom of the distributor branch pipe is 20 mm.

[0046] Another embodiment is different in that the length of the slag discharge hole at the bottom of the distributor branch pipe is 150 mm.

[0047] Another embodiment is different in that the length of the slag discharge hole at the bottom of the distributor branch pipe is 175 mm.

[0048] Another embodiment is different in that the length of the slag discharge hole at the bottom of the distributor branch pipe is 200 mm.

[0049] Another embodiment is different in that the air outlet hole of the distributor main pipe is arranged in the direction of an angle of 40° with the axis of the distributor main pipe.

[0050] Another embodiment is different in that the air outlet hole of the distributor main pipe is arranged in the direction of an angle of 50° with the axis of the distributor main pipe.

[0051] Another embodiment is different in that the air outlet hole of the distributor main pipe is arranged in the direction of an angle of 60° with the axis of the distributor main pipe.

[0052] Another embodiment is different in that the air outlet hole of the distributor main pipe is arranged in the direction of an angle of 70° with the axis of the distributor main pipe.

[0053] Another embodiment is different in that the air outlet hole of the distributor branch pipe is arranged in the direction of an angle of 40° with the axis of the distributor branch pipe.

[0054] Another embodiment is different in that the air outlet hole of the distributor branch pipe is arranged in the direction of an angle of 50° with the axis of the distributor branch pipe.

[0055] Another embodiment is different in that the air outlet hole of the distributor branch pipe is arranged in the direction of an angle of 60° with the axis of the distributor branch pipe.

[0056] Another embodiment is different in that the air outlet hole of the distributor branch pipe is arranged in the direction of an angle of 70° with the axis of the distributor branch pipe.

[0057] The following is the process flow and principle of the present invention:

[0058] The raw coal gas from the gasifier enters the Venturi scrubber 7 through the gas duct 6 from the raw coal gas inlet 18. The Venturi scrubber 7 is vertically installed. A water jacket 19 is provided on the outside of the throat of the Venturi scrubber. A number of spray holes 20 evenly distributed along the circumference are provided on the throat of the Venturi scrubber. The condensate sent from the latter process section serves as flushing water and tangentially enters the water jacket 19 from the Venturi spray water inlet 5. The spray water swirls in the water jacket 19 and sprays out from the spray holes 20, contacting the raw coal gas at the throat of the Venturi scrubber. The humidified raw coal gas enters the distributor 9 under the action of pressure difference and gravity. The solid particles in the raw coal gas enter the water bath through the slag discharge pipe 10 of the main pipe of the distributor and the slag discharge holes 25 of the branch pipes of the distributor, and flow out of the scrubbing tower from the black water outlet Ⅰ 12 or the black water outlet Ⅱ 14 of the scrubbing tower. The gas phase overflows from the gas outlet holes of the main pipe and branch pipes of the distributor, reaches the tray 4 after passing through the water bath, contacts the condensate of the raw coal gas at the tray washing water inlet 3 on the tray 4. After humidification and cooling, most of the fine ash overflows with the tray washing water into the water bath. When the gas phase continues to rise and encounters the cyclone demister 2, the liquid with reduced kinetic energy and a small amount of fine ash fall on the tray 4 under the action of gravity due to the collision of the cyclone demister blades. The clean water gas enters the latter process section from the water gas outlet 1 at the top of the scrubbing tower.

Claims

1. A raw coal gas scrubbing tower for water-coal slurry gasification, characterized in that it comprises a tower body, and a raw coal gas outlet is arranged at the top of the tower body; inside the tower body, a cyclone demister, a tray, a Venturi scrubber and a distributor are successively arranged from top to bottom; a tray washing water inlet is arranged on the tower body wall between the cyclone demister and the tray; a Venturi raw coal gas inlet, a Venturi spray water inlet, a Venturi flushing water outlet and a high-pressure ash water inlet are successively arranged from top to bottom on the tower body wall between the tray and the distributor; a scrubbing tower black water outlet is arranged on the tower body wall below the distributor; the Venturi raw coal gas inlet is connected to the Venturi scrubber through a gas guide pipe; the Venturi scrubber is vertically installed, and the lower end is connected to the distributor through a distributor inlet pipe, and the distributor is fixed on the scrubbing tower wall through a support groove; a water jacket is arranged outside the throat of the Venturi scrubber, and a plurality of spray holes evenly distributed along the circumference are arranged on the throat of the Venturi scrubber. The Venturi spray water tangentially enters the water jacket and contacts the raw coal gas at the Venturi throat. The humidified raw coal gas enters the distributor under the action of pressure difference and gravity; the distributor comprises a main pipe, a slag discharge pipe is arranged at the bottom of the main pipe, a plurality of branch pipes are arranged on both sides of the main pipe, and slag discharge holes are arranged at the bottoms of the branch pipes. Two rows of gas outlet holes are arranged on both the main pipe and the branch pipes of the distributor; the solid particles in the raw coal gas enter the water bath through the slag discharge pipe of the main pipe of the distributor and the slag discharge holes of the branch pipes of the distributor, and flow out of the scrubbing tower from the scrubbing tower black water outlet. The gas phase part overflows from the gas outlet holes of the main pipe and the branch pipes of the distributor, reaches the tray after passing through the water bath, contacts the condensate at the tray washing water inlet on the tray, and after humidifying and cooling, most of the fine ash overflows into the water bath with the tray washing water. When the gas phase continues to rise and encounters the cyclone demister, under the collision of the blades of the cyclone demister, the liquid with lost kinetic energy and a small part of the fine ash fall on the tray under the action of gravity, and the clean raw coal gas enters the subsequent process from the raw coal gas outlet at the top of the scrubbing tower; the diameter of the spray holes of the Venturi scrubber is 5-10 mm, and the included angle between the center line of the spray holes of the Venturi scrubber and the axis of the Venturi throat is 20°-40°; the diameter of the slag discharge pipe at the bottom of the main pipe of the distributor is 400-600 mm; the slag discharge holes at the bottom of the branch pipes of the distributor are long strip holes, the width of the slag discharge holes at the bottom of the branch pipes of the distributor is 10-20 mm, and the length of the slag discharge holes at the bottom of the branch pipes of the distributor is 150-200 mm; the gas outlet holes of the main pipe of the distributor are arranged in the direction with an included angle of 40°-70° with the axis of the main pipe of the distributor; the gas outlet holes of the branch pipes of the distributor are arranged in the direction with an included angle of 40°-70° with the axis of the branch pipes of the distributor.

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