阅读说明：本技术 一种用于煤气化系统的固液分离装置及方法 (Solid-liquid separation device and method for coal gasification system ) 是由 袁悦 王鹏杰 陶继业 任永强 李小宇 刘刚 马腾飞 于 2021-01-09 设计创作，主要内容包括：本发明公开了一种用于煤气化系统的固液分离装置及方法,利用第一挡板和第二挡板将空心轴和转动筒体内壁之间空腔间隔成反吹区域和负压区,将转动筒体设置于水槽内,待过滤煤气化液体穿过转动筒体外圈的滤网进入负压区,过滤后的液体通过排水管排出,转动过程中由于负压区内为负压状态,在转动筒体的滤网外表面形成飞灰膜滤饼,当转动筒体转动至反吹区域时,反吹区域内从内部形成正压,滤网外表面的飞灰膜滤饼松动或脱落,再经过刮刀将转动筒体表面的飞灰膜滤饼刮下,本申请采用转动滤网起到过滤并携带固体飞灰的作用,能够将液体中的飞灰带离实现水体的初步净化,并且能够循环转动清除滤网上的飞灰膜滤饼,结构简单,工作效率高,且占地面积小。(The invention discloses a solid-liquid separation device and a method for a coal gasification system, wherein a cavity between a hollow shaft and the inner wall of a rotary cylinder is divided into a back-flushing area and a negative pressure area by a first baffle and a second baffle, the rotary cylinder is arranged in a water tank, coal gasification liquid to be filtered passes through a filter screen on the outer ring of the rotary cylinder to enter the negative pressure area, the filtered liquid is discharged through a drain pipe, a fly ash membrane filter cake is formed on the outer surface of the filter screen of the rotary cylinder due to the negative pressure state in the negative pressure area during the rotation process, when the rotary cylinder rotates to the back-flushing area, positive pressure is formed from the inside in the back-flushing area, the fly ash membrane filter cake on the outer surface of the filter screen is loosened or falls off, and then the fly ash membrane filter cake on the surface of the rotary cylinder is scraped by a scraper, the application adopts the rotary filter screen to play the roles, and can the cyclic rotation clear away the flying dust membrane filter cake on the filter screen, simple structure, work efficiency is high, and area is little.)

1. The solid-liquid separation device for the coal gasification system is characterized by comprising a water tank (1), a rotary drum (2) and a scraper (3), wherein the rotary drum (2) comprises a hollow shaft (4) and a rotary cylinder body (5), a circle of filter screen (6) is arranged on the circumference of the outer ring of the rotary cylinder body (5), the rotary cylinder body (5) is sleeved on the hollow shaft (4) and can rotate relative to the hollow shaft (4), two first baffles (7) and two second baffles (8) which are arranged at an included angle are fixed on the hollow shaft (4), one ends of the first baffles (7) and the second baffles (8) are fixed on the hollow shaft (4), the other three sides of the first baffles (7) and the second baffles (8) are in contact with the inner wall of the rotary cylinder body (5), the first baffles (7) and the second baffles (8) separate a cavity between the inner wall of the hollow shaft (4) and the inner wall of the rotary cylinder body (5), one of the spaces is a blowback area, and the other space is a negative pressure area; through holes are formed in the shaft walls of the hollow shafts (4) in the two independent spaces, air blowing pipes (9), negative pressure pipes (10) and drain pipes (11) are arranged in the hollow shafts (4), one ends of the air blowing pipes (9) are communicated with the through holes in the hollow shafts (4) in the back blowing area, and one ends of the negative pressure pipes (10) are communicated with the through holes in the hollow shafts (4) in the negative pressure area; the rotary cylinder (5) is arranged in the water tank of the water tank (1), the scraper (3) is fixed on the outer side of the rotary cylinder (5), and one end of the scraper (3) is in contact with the outer side of the rotary cylinder (5).

2. The solid-liquid separation device for a coal gasification system according to claim 1, wherein the lower end of the first baffle (7) is in contact with the hollow shaft (4), the left and right sides of the first baffle (7) are in contact with the inner wall of the rotary cylinder (5), the upper end of the first baffle (7) is in contact with the circumferential inner wall of the rotary cylinder (5), the lower end of the second baffle (8) is in contact with the hollow shaft (4), the left and right sides of the second baffle (8) are in contact with the inner wall of the rotary cylinder (5), the upper end of the second baffle (8) is in contact with the circumferential inner wall of the rotary cylinder (5), and the rotary cylinder (5) rotates relative to the first baffle (7), the second baffle (8) and the hollow shaft (4).

3. The solid-liquid separation device for the coal gasification system according to claim 1, wherein the angle between the first baffle (7) and the second baffle (8) is 30-60 °, and the angle between the second baffle 8 and the horizontal plane is 10-20 °.

4. The solid-liquid separation device for the coal gasification system according to claim 1, wherein the water tank (1) is provided with an agitator (12), and the water tank (1) is an arc-shaped water tank.

5. The solid-liquid separation device for the coal gasification system according to claim 1, wherein the water tank (1) is provided with a water inlet (13) on one side and an overflow port (14) on the other side, the overflow port (14) is higher than a water outlet at the lower end of the water discharge pipe (11), and the overflow port (14) is lower than the lowest surface of the hollow shaft (4).

6. The solid-liquid separation device for the coal gasification system according to claim 1, wherein a boss (15) is provided on one side of the hollow shaft (4), a shoulder is provided on the other side of the hollow shaft, the rotary cylinder (5) is sleeved on the hollow shaft (4), the outer side of one end of the rotary cylinder (5) is in end face contact with the boss (15), the inner side of the other end of the rotary cylinder (5) is in end face contact with the shoulder, and a locking nut (16) is provided at the outer end of the hollow shaft (4).

7. The solid-liquid separation device for the coal gasification system according to claim 6, wherein a sealing gasket is arranged between the rotary cylinder (5) and the boss (15) and the end face of the shaft shoulder, and a bearing (17) is arranged between the rotary cylinder (5) and the hollow shaft (4).

8. The solid-liquid separation device for the coal gasification system according to claim 1, wherein the hollow shaft (4) is provided with an axial clamping groove, and the first baffle plate (7) and the second baffle plate (8) are nested and clamped in the axial clamping groove.

9. The solid-liquid separation device for the coal gasification system according to claim 1, wherein the other end of the gas blowing pipe (9) is connected to a gas pump, and the other end of the negative pressure pipe (10) is connected to a vacuum pump.

10. A solid-liquid separation method for a coal gasification system based on the solid-liquid separation device for a coal gasification system according to claim 1, comprising the steps of:

s1, mounting the solid-liquid separation device on the upper end of the water tank, and placing the rotary cylinder in the water tank;

s2, injecting liquid with filtering function into the water tank to make the liquid level of the liquid to be filtered higher than the water outlet at the lower end of the drain pipe and lower than the lower surface of the hollow shaft; the rotary cylinder is driven to rotate, vacuum is sucked to the negative pressure area at the same time, so that the negative pressure area in the rotary cylinder forms negative pressure, positive pressure is injected to the back blowing area, and the rotary cylinder is continuously driven to rotate to complete primary filtering and filter residue separation.

Technical Field

The invention belongs to a slag discharge filtering system, and particularly relates to a solid-liquid separation device and a solid-liquid separation method for a coal gasification system.

Background

Coal gasification refers to the process of converting solid fuels such as coal, coke, semi-coke, etc. into gas products and a small amount of residues by reacting with a gasification agent under the conditions of high temperature, normal pressure or pressurization. The gasifying agent is mainly water vapor, air (or oxygen) or their mixture, and the gasifying reaction includes a series of homogeneous and heterogeneous chemical reactions. The obtained gas product has different compositions according to the types of the raw materials, namely coal quality and gasifying agents and different gasification processes, and can be divided into air gas, semi-water gas, water gas and the like. The coal gasification process can be used for producing fuel gas, which is used as industrial kiln gas and city gas, and also used for producing synthesis gas, which is used as raw material for synthesizing ammonia, methanol and liquid fuel. Although the fluidized bed gasification technology has been greatly developed in recent years, new pressurized fluidized bed gasification processes such as high temperature kohler (HTW), U-Gas and the like and circulating fluidized bed process (CFB) have been developed successively, which solve the problems of excessive entrainment and the like in the atmospheric fluidized bed gasification to a certain extent, but still have the problems of high entrainment in coal Gas, high carbon content and difficult separation of entrainment, low carbon conversion rate, low effective components in coal Gas, high activity of coal, high ash melting point and the like.

Most importantly, the solid content of black water after the operation of slag discharging and washing units in the coal gasification process is high, so that the solid-liquid separation operation is necessary to be carried out on the black water, the energy consumption of a downstream water treatment unit is reduced, but the traditional vacuum belt filter has large floor area and unsatisfactory treatment capacity, and the water content of the obtained filter cake is high.

Disclosure of Invention

The invention aims to provide a solid-liquid separation device and a solid-liquid separation method for a coal gasification system, which are used for overcoming the defects of the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a solid-liquid separation device for a coal gasification system comprises a water tank, a rotary drum and a scraper, wherein the rotary drum comprises a hollow shaft and a rotary barrel body, a circle of filter screen is arranged on the circumference of the outer ring of the rotary barrel body, the rotary barrel body is sleeved on the hollow shaft and can rotate relative to the hollow shaft, two first baffle plates and two second baffle plates which are arranged at an included angle are fixed on the hollow shaft, one ends of the first baffle plates and one ends of the second baffle plates are fixed on the hollow shaft, the other three sides of the first baffle plates and the other three sides of the second baffle plates are in contact with the inner wall of the rotary barrel body, the first baffle plates and the second baffle plates separate a cavity between the hollow shaft and the inner wall of the rotary; through holes are formed in the shaft walls of the hollow shafts in the two independent spaces, an air blowing pipe, a negative pressure pipe and a drain pipe are arranged in the hollow shaft, one end of the air blowing pipe is communicated with the through hole in the hollow shaft in the back blowing area, and one end of the negative pressure pipe is communicated with the through hole in the hollow shaft in the negative pressure area; the rotating cylinder is arranged in the water tank, the scraper is fixed on the outer side of the rotating cylinder, and one end of the scraper is in contact with the outer side of the rotating cylinder.

Further, the lower end of the first baffle is in contact with the hollow shaft, the left side and the right side of the first baffle are in contact with the inner wall of the rotating barrel, the upper end of the first baffle is in contact with the circumferential inner wall of the rotating barrel, the lower end of the second baffle is in contact with the hollow shaft, the left side and the right side of the second baffle are in contact with the inner wall of the rotating barrel, the upper end of the second baffle is in contact with the circumferential inner wall of the rotating barrel, and the rotating barrel rotates relative to the first baffle, the.

Further, the included angle between the first baffle plate and the second baffle plate is 30-60 degrees, and the included angle between the second baffle plate 8 and the horizontal plane is 10-20 degrees.

Furthermore, a stirrer is arranged in the water tank, and the water tank adopts an arc-shaped water tank.

Furthermore, one side of the water tank is provided with a water inlet, the other side of the water tank is provided with an overflow port, the overflow port is higher than a water outlet at the lower end of the drain pipe, and the overflow port is lower than the lowest surface of the hollow shaft.

Furthermore, one side of the hollow shaft is provided with a boss, the other side of the hollow shaft is provided with a shaft shoulder, the hollow shaft is sleeved with the rotary barrel, the outer side of one end of the rotary barrel is in end face contact with the boss, the inner side face of the other end of the rotary barrel is in end face contact with the shaft shoulder, and the outer end of the hollow shaft is provided with a locking nut.

Furthermore, sealing gaskets are arranged between the rotary cylinder body and the lug boss as well as between the rotary cylinder body and the end face of the shaft shoulder, and a bearing is arranged between the rotary cylinder body and the hollow shaft.

Furthermore, an axial clamping groove is formed in the hollow shaft, and the first baffle and the second baffle are both nested and clamped in the axial clamping groove.

Furthermore, the other end of the air blowing pipe is connected with the air pump, and the other end of the negative pressure pipe is connected with the vacuum pump.

A solid-liquid separation method of a coal gasification system comprises the following steps:

s1, mounting the solid-liquid separation device on the upper end of the water tank, and placing the rotary cylinder in the water tank;

s2, injecting liquid with filtering function into the water tank to make the liquid level of the liquid to be filtered higher than the water outlet at the lower end of the drain pipe and lower than the lower surface of the hollow shaft; the rotary cylinder is driven to rotate, vacuum is sucked to the negative pressure area at the same time, so that the negative pressure area in the rotary cylinder forms negative pressure, positive pressure is injected to the back blowing area, and the rotary cylinder is continuously driven to rotate to complete primary filtering and filter residue separation.

Compared with the prior art, the invention has the following beneficial technical effects:

according to the solid-liquid separation device for the coal gasification system, the circle of filter screen is arranged on the circumference of the outer ring of the rotary cylinder body, the rotary cylinder body is sleeved on the hollow shaft and can rotate relative to the hollow shaft, two first baffles and two second baffles which are arranged at an included angle are fixed on the hollow shaft, the other three sides of the first baffles and the other three sides of the second baffles are in contact with the inner wall of the rotary cylinder body, and a cavity between the hollow shaft and the inner wall of the rotary cylinder body is partitioned into a back flushing area and a negative pressure area by the first baffles and the second baffles; through holes are formed in the shaft walls of the hollow shafts in the two independent spaces, one end of each air blow pipe is communicated with the through hole in the hollow shaft in the back blowing area, one end of each negative pressure pipe is communicated with the through hole in the hollow shaft in the negative pressure area, the rotating cylinder is arranged in the water tank, and air is blown into the back blowing area through the air blow pipes by the rotation of the rotating cylinder, so that positive pressure is formed in the back blowing area; the negative pressure pipe inhales air to enable a negative pressure area to form a negative pressure state, coal gasification liquid to be filtered enters the negative pressure area through a filter screen on the outer ring of the rotary cylinder body to complete primary filtration, and the filtered liquid is discharged through a drain pipe; in the rotating process of the rotating cylinder body, because the negative pressure area is in a negative pressure state, the fly ash membrane filter cake is formed on the outer surface of the filter screen of the rotating cylinder body, when the rotating cylinder body rotates to the back flushing area, positive pressure is formed inside the back flushing area, the fly ash membrane filter cake on the outer surface of the filter screen is loosened or falls off, the fly ash membrane filter cake on the surface of the rotating cylinder body is scraped by a scraper, one-time solid-liquid separation operation is completed, the filter screen plays a role in filtering and carrying solid fly ash, the fly ash in liquid can be carried away to realize primary purification of water, and the fly ash membrane filter cake on the filter screen can be removed in a circulating rotation mode, the working efficiency is high, the blocking problem caused by the fact that the filter screen is.

Furthermore, the included angle between the first baffle and the second baffle is 30-60 degrees, the included angle between the second baffle 8 and the horizontal plane is 10-20 degrees, a small-area back blowing area is formed, and the flying ash membrane filter cake can fall off easily.

Furthermore, a stirrer is arranged in the water tank, and the water tank adopts an arc-shaped water tank to prevent liquid from precipitating.

Furthermore, a water inlet is formed in one side of the water tank, an overflow port is formed in the other side of the water tank, and the liquid level can be effectively prevented from being too high.

Furthermore, one side of the hollow shaft is provided with a boss, the other side of the hollow shaft is provided with a shaft shoulder, the hollow shaft is sleeved with the rotary barrel, the outer side of one end of the rotary barrel is in end face contact with the boss, the inner side face of the other end of the rotary barrel is in end face contact with the shaft shoulder, and the outer end of the hollow shaft is provided with a locking nut.

Furthermore, an axial clamping groove is formed in the hollow shaft, and the first baffle and the second baffle are both nested and clamped in the axial clamping groove, so that the hollow shaft is simple in structure and convenient to mount and dismount.

The invention relates to a solid-liquid separation method of a coal gasification system, which utilizes the solid-liquid separation device to be arranged at the upper end of a water tank, so that a rotary cylinder body is arranged in the water tank; the liquid level of the liquid to be filtered is higher than the water outlet at the lower end of the drain pipe and lower than the lower surface of the hollow shaft by injecting the liquid with the filtering function into the water tank; the rotary cylinder is driven to rotate, vacuum is sucked to the negative pressure area at the same time, so that the negative pressure area in the rotary cylinder forms negative pressure, positive pressure is injected to the back blowing area, the rotary cylinder is continuously driven to rotate, primary filtration and filter residue separation are completed, the method is simple, and the filtration efficiency is high.

Drawings

FIG. 1 is a schematic structural diagram of a solid-liquid separation apparatus in an embodiment of the present invention.

Fig. 2 is a schematic view of a mounting structure of the rotary cylinder in the embodiment of the invention.

FIG. 3 is a schematic view of a connection structure of an application system of the solid-liquid separation apparatus according to the embodiment of the present invention.

Wherein, 1, a water tank; 2. a drum; 3. a scraper; 4. a hollow shaft; 5. rotating the cylinder; 6. filtering with a screen; 7. a first baffle plate; 8. a second baffle; 9. an air blowing pipe; 10. a negative pressure tube; 11. a drain pipe; 12. a stirrer; 13. a water inlet; 14. an overflow port; 15. a boss; 16. locking the nut; 17. a bearing; 18. a drive wheel; 19. a drive device; 20. a cyclone separator.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

as shown in fig. 1 to 3, a solid-liquid separation device for a coal gasification system comprises a water tank 1, a rotary drum 2 and a scraper 3, wherein the rotary drum 2 comprises a hollow shaft 4 and a rotary cylinder 5, a circle of filter screen 6 is arranged on the circumference of the outer ring of the rotary cylinder 5, the rotary cylinder 5 is sleeved on the hollow shaft 4 and can rotate relative to the hollow shaft 4, two first baffles 7 and two second baffles 8 arranged at an included angle are fixed on the hollow shaft 4, one end of each of the first baffles 7 and one end of each of the second baffles 8 are fixed on the hollow shaft 4, the other three sides of each of the first baffles 7 and the other three sides of each of the second baffles 8 are in contact with the inner wall of the rotary cylinder 5, the cavities between the hollow shaft 4 and the inner wall of the rotary cylinder 5 are separated into two independent spaces by the first baffles 7 and the second; through holes are formed in the shaft walls of the hollow shafts 4 in the two independent spaces, an air blowing pipe 9, a negative pressure pipe 10 and a water discharging pipe 11 are arranged in the hollow shaft 4, one end of the air blowing pipe 9 is communicated with the through hole in the hollow shaft 4 in one of the independent spaces, one end of the negative pressure pipe 10 is communicated with the through hole in the hollow shaft 4 in the other independent space, one end of the water discharging pipe 11 is communicated with an external water pumping device through the hollow shaft 4, and the other end of the water discharging pipe penetrates through the shaft wall of the hollow shaft; in the application, the air blowing pipe 9 is communicated with a through hole on the hollow shaft 4 in the back blowing area, and the negative pressure pipe 10 is communicated with a through hole on the hollow shaft 4 in the negative pressure area; the rotary cylinder 5 is arranged in the water tank of the water tank 1, the scraper 3 is fixed on the outer side of the rotary cylinder 5, and one end of the scraper 3 is in contact with the outer side of the rotary cylinder 5. When the coal gasification device is used, coal gasification liquid to be filtered is injected into the water tank, the liquid level in the water tank is lower than the lowest end of a back flushing area in the rotary cylinder 5, and the liquid level in the water tank is higher than a water outlet of the drain pipe 11, the rotary cylinder 5 rotates in the filtering process, and air is blown into the back flushing area by the air blowing pipe 9, so that positive pressure is formed in the back flushing area; the negative pressure pipe 10 sucks air to enable a negative pressure area to form a negative pressure state, coal gasification liquid to be filtered enters the negative pressure area through the filter screen 6 on the outer ring of the rotary cylinder 5 to complete primary filtration, and the filtered liquid is discharged through the drain pipe 11; in the rotating process of the rotating cylinder body 5, because the inside of the negative pressure area is in a negative pressure state, a fly ash membrane filter cake is formed on the outer surface of a filter screen 6 of the rotating cylinder body 5, the first baffle 7, the second baffle 8 and the hollow shaft 4 are all fixed, when the rotating cylinder body 5 rotates to a back flushing area, positive pressure is formed inside the back flushing area, the fly ash membrane filter cake on the outer surface of the filter screen 6 is loosened or falls off, the fly ash membrane filter cake on the surface of the rotating cylinder body 5 is scraped by a scraper, one solid-liquid separation operation is completed, the filter screen 6 plays a role in filtering and carrying solid fly ash, the fly ash in liquid can be carried away to realize primary purification of water, and the fly ash membrane filter cake on the filter screen can be removed in a circulating rotation mode, the structure is simple. The other end of the air blowing pipe 9 is connected with an air pump, and the other end of the negative pressure pipe 10 is connected with a vacuum pump.

The first baffle 7 and the second baffle 8 are mounted in the same structure, namely: 7 lower extremes of first baffle and hollow shaft 4 contact, 7 left and right sides of first baffle and the contact of 5 inner walls of rotation barrel, 7 upper ends of first baffle and the contact of 5 circumference inner walls of rotation barrel, 8 lower extremes of second baffle and the contact of hollow shaft 4, 8 left and right sides of second baffle and the contact of 5 inner walls of rotation barrel, 8 upper ends of second baffle and the contact of 5 circumference inner walls of rotation barrel, first baffle 7, second baffle 8 and hollow shaft 4 are fixed, rotate the relative first baffle 7 of barrel 5, second baffle 8 and hollow shaft 4 rotate.

The included angle between the first baffle 7 and the second baffle 8 is 30-60 degrees, the included angle between the second baffle 8 and the horizontal plane is 10-20 degrees, the included angle between the first baffle 7 and the horizontal plane is 40-80 degrees, an acute angle area formed between the first baffle 7 and the second baffle 8 is a back blowing area, and the back blowing area is positioned at the tail end of the rotary cylinder body in rotary operation, namely the rotary cylinder body rotates a filter screen to enter liquid in the water tank after passing through the back blowing area.

The stirrer 12 is arranged in the water tank 1 and is used for stirring liquid in the water tank, so that the precipitation in the water tank is prevented, and the liquid purification efficiency is improved. The water tank 1 adopts an arc-shaped water tank which is similar to the arc of the rotary cylinder 5; one side of the water tank 1 is provided with a water inlet 13, the other side of the water tank is provided with an overflow port 14, the overflow port 14 is higher than a water outlet at the lower end of the drain pipe 11, and the overflow port 14 is lower than the lowest surface of the hollow shaft 4, so that liquid is prevented from being discharged from the hollow shaft 4 when passing through a negative pressure region.

As shown in fig. 2, the section of the rotary cylinder 5 is taken by taking the mounting surface of the first baffle 7 as a section; a boss 15 is arranged on one side of the hollow shaft 4, a shaft shoulder is arranged on the other side of the hollow shaft 4, the rotating cylinder 5 is sleeved on the hollow shaft 4, the outer side of one end of the rotating cylinder 5 is in contact with the end face of the boss 15, the inner side face of the other end of the rotating cylinder 5 is in contact with the end face of the shaft shoulder, a locking nut 16 is arranged at the outer end of the hollow shaft 4, and the rotating cylinder 5 is circumferentially fixed on the hollow shaft; sealing gaskets are arranged between the rotary cylinder body 5 and the lug boss 15 and between the rotary cylinder body and the end face of the shaft shoulder. A bearing 17 is arranged between the rotating cylinder 5 and the hollow shaft 4, so that the friction force between the rotating cylinder 5 and the hollow shaft 4 is reduced, the rotating efficiency is improved, and the energy consumption is reduced.

Be equipped with the axial draw-in groove on the hollow shaft 4, first baffle 7 and second baffle 8 are all nested the card and locate the axial draw-in groove, during the installation, will rotate on 5 frames of barrel are fixed in hollow shaft 4 earlier, then insert the axial draw-in groove of locating on hollow shaft 4 with first baffle 7 and second baffle 8 from rotating 5 outer lanes of barrel, then in rotating 5 outer lanes of barrel installation filter screen 6, fix scraper 3 and set up in the rotation barrel outside at last.

The driving wheel 18 is arranged on the outer side of the rotary cylinder 5 and is driven by the driving device 19, so that the structure is simple, and the installation and the maintenance are convenient. As shown in fig. 1, the driving device 19 adopts a driving motor, the driving motor is connected with the driving wheel 18 through a belt, the structure is simple, the installation space is reduced, or the driving motor is directly connected with the driving wheel through a gear or a driving shaft.

The solid content of the black water is about 30 percent, the working pressure of a vacuum pump is negative pressure of-0.1 KPa, the power of a motor is 0.75kw, the processing capacity is 0.6kg/S, and filter screens with different apertures can be arranged according to the particle size of the liquid waste residue to be filtered. Can treat fly ash particles with the medium particle size of 1-80 mu m.

The 3 outsides of scraper are equipped with the baffle, and 3 bottoms of scraper are equipped with the transmission band, and the filter cake lifted off through the scraper is carried to 20 entrances of cyclone by the transmission band and is carried out the secondary filter operation, wraps up the one deck filter cloth on the cyclone 20 inner wall, through the moisture in the centrifugal action separation filter cake, the filter cloth is through dismantling washing repeatedly usable, realizes the separation requirement through adjusting 20 rotational speeds of cyclone. Except the back blowing area, the space between the rotating cylinder 5 and the hollow shaft 4 is in a negative pressure state, and back blowing operation is carried out after the rotating cylinder 5 rotates to the back blowing area. The liquid flowing out from the overflow port contains part of the solid particles of the fly ash, so the overflow liquid is circulated to the water tank to separate the fly ash particles again. Adopt this application solid-liquid separation equipment to carry out preliminary solid separation to introduce rotatory vacuum separator in filter cake collection department and can make filter cake water content control within 2%, effectively promote the solid-liquid separation effect, have certain industrial application and worth.

The solid-liquid separation method for a coal gasification system based on the solid-liquid separation device for the coal gasification system comprises the following steps:

s1, mounting the solid-liquid separation device on the upper end of the water tank, and placing the rotary cylinder 5 in the water tank 1;

s2, injecting liquid with filtering function into the water tank 1 to enable the liquid level of the liquid to be filtered to be higher than the water outlet at the lower end of the drain pipe 11 and lower than the lower surface of the hollow shaft 4; the rotary cylinder 5 is driven to rotate, vacuum is sucked to the negative pressure area at the same time, so that the negative pressure area in the rotary cylinder 5 forms negative pressure, positive pressure is injected to the back blowing area, coal gasification liquid to be filtered passes through a filter screen 6 on the outer ring of the rotary cylinder 5 to enter the negative pressure area, primary filtration is completed, and the filtered liquid is discharged through a drain pipe 11; in the rotation process of the rotary cylinder body 5, as the negative pressure area is in a negative pressure state, the fly ash membrane filter cake is formed on the outer surface of the filter screen 6 of the rotary cylinder body 5, when the rotary cylinder body 5 rotates to the back blowing area, positive pressure is formed inside the back blowing area, the fly ash membrane filter cake on the outer surface of the filter screen 6 loosens or falls off, and the fly ash membrane filter cake on the surface of the rotary cylinder body 5 is scraped by a scraper, so that one solid-liquid separation operation is completed. The circulating rotating type liquid filtering device is simple and convenient, can quickly filter liquid, can clean the filter screen in real time, prevents the filter screen from being blocked, reduces the filtering efficiency, is simple in structure and convenient to install, adopts a circulating rotating filtering structure, can keep the filter screen in an effective working state, and realizes efficient filtering.