Equipment for recycling chlorosilane in waste gas

Abstract

The utility model discloses equipment for recycling chlorosilane in waste gas again, which comprises a recycling tower, a gas inlet is arranged at the front end of the recycling tower, a gas exhaust hole is arranged at the top end of the recycling tower, a silicon tetrachloride filling pipe is arranged at the bottom of the recycling tower, and a cooling box is arranged at the tail end of the silicon tetrachloride filling pipe. And a feeding opening is formed in the bottom of the cooling box, a first baffle is arranged in the portion, above the exhaust hole, of the recovery tower, and a second baffle is arranged in the portion, above the first baffle, of the recovery tower. By arranging a series of structures, liquid silicon tetrachloride is in contact with waste gas, chlorosilane in the waste gas is cooled, chlorosilane which is difficult to condense in the waste gas is adsorbed at low temperature, the flow rate of the waste gas in the tower is slowed down, the waste gas can be fully in contact with the liquid silicon tetrachloride in the tower, the waste gas adsorption and purification efficiency is higher, and the waste gas purification effect is better. The liquid silicon tetrachloride can fully adsorb chlorosilane for recovery, so that impurities are prevented from entering the tower to pollute the internal space.

Description

Technical Field

[0001] The utility model relates to the technical field of waste gas treatment, in particular to equipment for recovering chlorosilane in waste gas. Background Art

[0002] At present, the modified Siemens process is widely used in the production of polysilicon. This process involves chemical vapor deposition of trichlorosilane and hydrogen on the surface of the silicon core at around 1000°C. The main components of the exhaust gas after the reaction are chlorosilane (trichlorosilane, silicon tetrachloride and dichlorosilane), hydrogen and HCl.

[0003] At present, the tail gas after the reaction is mainly recycled and reused through dry recovery. A small amount of HCL is carried in the reduction cycle material in the adsorption material and then enters the reduction distillation system. The dry recovery has a low efficiency in purifying and recovering the waste gas, and it is impossible to efficiently adsorb and recover the chlorosilane in the waste gas. Utility Model Content

[0004] The utility model aims to provide a device for recovering chlorosilane in waste gas to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a device for recovering chlorosilane in waste gas, comprising a recovery tower, the front end of which is provided with an air inlet, the top of which is provided with an exhaust hole, the bottom of which is provided with a silicon tetrachloride filling pipe, and the end of which is provided with a cooling box.

[0006] Preferably, a feeding port is provided at the bottom of the cooling box. Before the recovery tower 1 is operated, silicon tetrachloride is firstly added into the cooling box from the feeding port. The cooling box cools the silicon tetrachloride by Freon to make it liquid.

[0007] Preferably, a first baffle is provided inside the recovery tower above the exhaust hole, and a second baffle is provided inside the recovery tower above the first baffle, one end of the first baffle is inclined to the left, and the inclined end of the first baffle is away from the inner wall of the recovery tower, and one end of the second baffle is inclined to the right, and the inclined end of the second baffle is away from the inner wall of the recovery tower. When the recovery tower sucks the exhaust gas into the tower through the air inlet, the exhaust gas flows upward, is guided to flow to the left after contacting the first baffle, flows upward from the inclined end of the first baffle, is blocked by the second baffle and flows to the right, and flows upward from the inclined end of the second baffle to slow down the flow rate of the exhaust gas in the tower.

[0008] Preferably, the first baffle and the second baffle form a group, and two groups of first baffles and second baffles are vertically arranged inside the recovery tower. A plurality of effervescent devices are arranged in an annular pattern inside the recovery tower above each group of the first baffle and the second baffle. One end of a plurality of the effervescent devices on the same plane is commonly connected to an annular tube, and one end of a plurality of the annular tubes is commonly connected to a diversion pipe. A guide pipe is arranged at the bottom end of the diversion pipe, and a booster pump is arranged inside the guide pipe below the diversion pipe. When the waste gas flows in the tower, the guide pipe extracts the liquid silicon tetrachloride input into the tower through the silicon tetrachloride filling pipe through the booster pump, transports it to the annular tube, and then sprays it out through a plurality of effervescent devices, contacts with the waste gas to cool the chlorosilane in the waste gas, and performs low-temperature adsorption of the difficult-to-condense chlorosilane in the waste gas.

[0009] Preferably, the inside of the air inlet is detachably installed with an installer, the inside of which is plugged with a filter element, the installer is threadedly connected to the air inlet, and when exhaust gas is input, the filter element will filter the particulate impurities contained in the exhaust gas to prevent the impurities from entering the tower and polluting the internal space.

[0010] Preferably, a temperature sensor is provided inside the recovery tower near the second baffle at the top, and the temperature sensor is used to detect the temperature inside the tower. When the internal temperature reaches the critical value of silicon tetrachloride gasification temperature, the waste gas purification is stopped, and the silicon tetrachloride is refluxed through the silicon tetrachloride filling pipe to the cooling box for cooling.

[0011] Preferably, four ground support columns are arranged at the bottom of the outer surface of the recovery tower to support the recovery tower and ensure the stability of the recovery tower.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] 1. The equipment for recovering chlorosilane in the waste gas cools silicon tetrachloride through Freon in a cooling box to make it liquid. The cooling box contains a circulating pump, which inputs liquid silicon tetrachloride into the bottom of the recovery tower to make the liquid silicon tetrachloride contact with the waste gas, cool the chlorosilane in the waste gas, and perform low-temperature adsorption of the difficult-to-condense chlorosilane in the waste gas.

[0014] 2. The equipment for recovering chlorosilane in waste gas has a first baffle box and a second baffle box which are arranged obliquely. When the recovery tower sucks waste gas into the tower through the air inlet, the waste gas flows upward, is guided to flow to the left after contacting the first baffle, flows upward from the inclined end of the first baffle, is blocked by the second baffle and flows to the right, and flows upward from the inclined end of the second baffle to slow down the flow rate of the waste gas in the tower, ensuring that the waste gas can fully contact with the liquid silicon tetrachloride in the tower, so that the waste gas adsorption and purification efficiency is higher, and the liquid silicon tetrachloride can fully adsorb chlorosilane for recovery.

[0015] 3. The chlorosilane in the waste gas is recovered again. When the waste gas is input through the filter element, the filter element will filter the particulate impurities contained in the waste gas to prevent the impurities from entering the tower and polluting the internal space. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 This is a schematic diagram of the internal structure of the recovery tower of the utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the first baffle and the second baffle of the utility model;

[0019] Figure 4 The utility model is a schematic diagram of the operation principle of the recovery tower structure.

[0020] In the figure: 1. Recovery tower; 2. Floor support column; 3. Silicon tetrachloride filling pipe; 4. Cooling box; 5. Feeding port; 6. Exhaust hole; 7. Air inlet; 8. Installer; 9. Filter element; 10. Guide pipe; 11. Pressure pump; 12. Temperature sensor; 13. Eluent; 14. First baffle; 15. Second baffle; 16. Ring pipe; 17. Diverter pipe. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] like Figures 1 to 4As shown, the present embodiment is a device for recovering chlorosilane in waste gas, comprising a recovery tower 1, wherein an air inlet 7 is arranged at the front end of the recovery tower 1. When the waste gas is purified, the front end of the air inlet 7 is connected to the waste gas absorption device to discharge the waste gas into the recovery tower 1. An exhaust hole 6 is arranged at the top of the recovery tower 1, and the purified waste gas is discharged through the exhaust hole 6. A silicon tetrachloride filling pipe 3 is arranged at the bottom of the recovery tower 1, and silicon tetrachloride in a low-temperature state is injected into the recovery tower 1 to cool the chlorosilane in the waste gas. A cooling box 4 is arranged at the end of the silicon tetrachloride filling pipe 3, and the cooling box 4 cools the silicon tetrachloride in a normal temperature state and converts it into a liquid state.

[0024] Specifically, a feeding port 5 is provided at the bottom of the cooling box 4. Before the recovery tower 1 is operated, silicon tetrachloride is firstly added into the cooling box 4 from the feeding port 5. The cooling box 4 cools the silicon tetrachloride by Freon to make it liquid.

[0025] Furthermore, a first baffle 14 is provided inside the recovery tower 1 above the exhaust hole 6, and a second baffle 15 is provided inside the recovery tower 1 above the first baffle 14. One end of the first baffle 14 is inclined to the left, and the inclined end of the first baffle 14 is away from the inner wall of the recovery tower 1. One end of the second baffle 15 is inclined to the right, and the inclined end of the second baffle 15 is away from the inner wall of the recovery tower 1. When the recovery tower 1 sucks the exhaust gas into the tower through the air inlet 7, the exhaust gas flows upward, is guided to flow to the left after contacting the first baffle 14, flows upward from the inclined end of the first baffle 14, is blocked by the second baffle 15 and flows to the right, and flows upward from the inclined end of the second baffle 15 to slow down the flow rate of the exhaust gas in the tower.

[0026] Furthermore, the first baffle 14 and the second baffle 15 form a group, and two groups of first baffles 14 and second baffles 15 are vertically arranged inside the recovery tower 1, and a plurality of elutriators 13 are annularly arranged inside the recovery tower 1 above each group of first baffles 14 and second baffles 15, and one end of a plurality of elutriators 13 on the same plane is commonly connected to a ring pipe 16, and one end of a plurality of ring pipes 16 is commonly connected to a diversion pipe 17, and a guide pipe 10 is arranged at the bottom end of the diversion pipe 17, and a booster pump 11 is arranged inside the guide pipe 10 below the diversion pipe 17. When the waste gas flows in the tower, the guide pipe 10 extracts the liquid silicon tetrachloride input into the tower by the silicon tetrachloride filling pipe 3 through the booster pump 11, and transports it to the annular pipe 16, and then sprays it out through a plurality of elutriators 13, contacts with the waste gas to cool the chlorosilane in the waste gas, and performs low-temperature adsorption of the difficult-to-condense chlorosilane in the waste gas.

[0027] Furthermore, the inside of the air inlet 7 is detachably installed with an installer 8, and the inside of the installer 8 is plugged with a filter element 9. The installer 8 and the air inlet 7 are threadedly connected. When the exhaust gas is input, the filter element 9 will filter the particulate impurities contained in the exhaust gas to prevent the impurities from entering the tower and polluting the internal space.

[0028] Furthermore, a temperature sensor 12 is provided inside the recovery tower 1 near the second baffle 15 at the top. The temperature sensor 12 is used to detect the temperature inside the tower. When the internal temperature reaches the critical value of the silicon tetrachloride gasification temperature, the waste gas purification is stopped and the silicon tetrachloride is refluxed through the silicon tetrachloride filling pipe 3 to the cooling box 4 for cooling.

[0029] Furthermore, four ground support columns 2 are arranged at the bottom of the outer surface of the recovery tower 1 to support the recovery tower 1 and ensure the stability of the recovery tower 1.

[0030] The method of use of this embodiment is as follows: the electrical components appearing in this application are all connected to an external power supply when in use. Before the recovery tower 1 is operated, silicon tetrachloride is first added to the cooling box 4 from the feeding port 5. The cooling box 4 cools the silicon tetrachloride through Freon to make it liquid. The cooling box 4 contains a circulating pump, which inputs the liquid silicon tetrachloride into the bottom of the recovery tower 1. Then, the guide pipe 10 extracts the liquid silicon tetrachloride input into the tower through the silicon tetrachloride filling pipe 3 through the pressure pump 11, and transports it to the annular pipe 16, and then sprays it out through a number of elutriators 13, and then the waste gas is input into the tower through the air inlet 7. When the waste gas is input, the filter element 9 will remove the waste gas. The particulate impurities contained in the waste gas are filtered to prevent the impurities from entering the tower and polluting the internal space. After the recovery tower 1 sucks the waste gas into the tower through the air inlet 7, the waste gas flows upward, and is guided to flow to the left after contacting the first baffle 14, and flows upward from the inclined end of the first baffle 14, and is blocked by the second baffle 15 to flow to the right, and flows upward from the inclined end of the second baffle 15 to slow down the flow rate of the waste gas in the tower, so that the liquid silicon tetrachloride contacts the waste gas, cools the chlorosilane in the waste gas, and low-temperature adsorbs the difficult-to-condense chlorosilane in the waste gas. After the chlorosilane in the waste gas is adsorbed, the silicon tetrachloride can be extracted by a circulating pump to separate the chlorosilane.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A device for recovering chlorosilane from waste gas, comprising a recovery tower (1), characterized in that: The front end of the recovery tower (1) is provided with an air inlet (7), the top end of the recovery tower (1) is provided with an exhaust hole (6), the bottom of the recovery tower (1) is provided with a silicon tetrachloride filling pipe (3), and the end of the silicon tetrachloride filling pipe (3) is provided with a cooling box (4).

2. The device for recovering chlorosilane from waste gas according to claim 1, characterized in that: The bottom of the cooling box (4) is provided with a loading port (5).

3. The device for recovering chlorosilane from waste gas according to claim 1, characterized in that: A first baffle (14) is arranged inside the recovery tower (1) above the exhaust hole (6); a second baffle (15) is arranged inside the recovery tower (1) above the first baffle (14); one end of the first baffle (14) is inclined toward the left, and the inclined end of the first baffle (14) is away from the inner wall of the recovery tower (1); one end of the second baffle (15) is inclined toward the right, and the inclined end of the second baffle (15) is away from the inner wall of the recovery tower (1).

4. The device for recovering chlorosilane from waste gas according to claim 3, characterized in that: The first baffle (14) and the second baffle (15) form a group. Two groups of first baffles (14) and second baffles (15) are vertically arranged inside the recovery tower (1). A plurality of effervescent devices (13) are annularly arranged inside the recovery tower (1) above each group of the first baffles (14) and the second baffle (15). One end of a plurality of the effervescent devices (13) on the same plane is commonly connected to an annular pipe (16). One end of a plurality of the annular pipes (16) is commonly connected to a shunt pipe (17). A guide pipe (10) is arranged at the bottom end of the shunt pipe (17). A pressure pump (11) is arranged inside the guide pipe (10) below the shunt pipe (17).

5. The device for recovering chlorosilane from waste gas according to claim 1, characterized in that: An installer (8) is detachably installed inside the air inlet (7), and a filter element (9) is plugged into the inside of the installer (8).

6. The device for recovering chlorosilane from waste gas according to claim 1, characterized in that: A temperature sensor (12) is provided inside the recovery tower (1) near the uppermost second baffle (15).

7. The device for recovering chlorosilane from waste gas according to claim 1, characterized in that: Four ground support columns (2) are arranged at the bottom of the outer surface of the recovery tower (1).

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