阅读说明：本技术 一种用于去除尾气中硅粉的系统 (System for be arranged in getting rid of silica flour in tail gas ) 是由 罗周 向春林 明勇 宋垒 于 2019-11-12 设计创作，主要内容包括：本发明公开了一种用于去除尾气中硅粉的系统,包括过滤装置和收集装置,所述过滤装置用于将尾气中的硅粉过滤出,所述收集装置用于收集所述过滤装置过滤出的硅粉；所述过滤装置和所述收集装置之间通过连通管连通,所述连通管上设置有第一阀门,所述第一阀门用于控制所述连通管的导通和截止。在本发明中,使包含有氯硅烷、氯化氢以及氢气的尾气通入过滤装置中,过滤装置将尾气中的硅粉过滤出,从而实现硅粉与氯硅烷、氯化氢以及氢气的分离。之后开启连通管上的第一阀门,从而使过滤出的硅粉通过连通管进入到收集装置中,从而实现了对硅粉的收集。本发明中的系统不仅能够将尾气中的硅粉过滤出,而且还能够将过滤出的硅粉进行收集。(The invention discloses a system for removing silicon powder in tail gas, which comprises a filtering device and a collecting device, wherein the filtering device is used for filtering the silicon powder in the tail gas out, and the collecting device is used for collecting the silicon powder filtered out by the filtering device; the filter device with communicate through communicating pipe between the collection device, be provided with first valve on communicating pipe, first valve is used for controlling switching on and closing of communicating pipe. In the invention, tail gas containing chlorosilane, hydrogen chloride and hydrogen is introduced into the filtering device, and the filtering device filters silicon powder in the tail gas, thereby realizing the separation of the silicon powder from the chlorosilane, the hydrogen chloride and the hydrogen. And then, a first valve on the communicating pipe is opened, so that the filtered silicon powder enters a collecting device through the communicating pipe, and the collection of the silicon powder is realized. The system disclosed by the invention not only can filter silicon powder in the tail gas, but also can collect the filtered silicon powder.)

1. A system for removing silicon powder in tail gas is characterized by comprising a filtering device and a collecting device, wherein the filtering device is used for filtering the silicon powder in the tail gas out, and the collecting device is used for collecting the silicon powder filtered out by the filtering device; the filter equipment with communicate through communicating pipe (5) between the collection device, be provided with first valve (4) on communicating pipe (5), first valve (4) are used for controlling switching on and cutting off of communicating pipe (5).

2. The system for removing silicon powder from tail gas according to claim 1, wherein the first valve (4) is controlled by a controller, and the controller controls the opening and closing of the first valve (4) according to a set time value.

3. The system for removing silicon powder from tail gas according to claim 1, wherein the filtering device comprises a first housing (1), a first filter element (2) is arranged in the first housing (1), and the first filter element (2) is used for blocking silicon powder;

be provided with import and export (3) on first casing (1), the import is located the below of first filter core (2), export (3) are located the top of first filter core (2), and tail gas is followed the import gets into first casing (1), process follow after the filtration of first filter core (2) export (3) flow.

4. The system for removing silicon powder from tail gas according to claim 3, wherein the filtering device further comprises a purging device for purging the silicon powder from the first filter element (2), and a purging port of the purging device is located above the first filter element (2).

5. The system for removing silicon powder from tail gas according to claim 4, wherein the tail gas filtered by the first filter element (2) is condensed by a condenser, and the separated hydrogen enters the purging device.

6. The system for removing silicon powder from exhaust gas according to claim 4, wherein the bottom of the first shell (1) is conical, and the conical bottom is used for gathering silicon powder.

7. The system for removing silicon powder from tail gas according to claim 6, wherein a first heater is arranged in the bottom of the first shell (1).

8. The system for removing silicon powder from tail gas according to claim 3, wherein the collecting device comprises a second shell (6), the second shell (6) is communicated with the first shell (1) through the communicating pipe (5), a discharge pipe is communicated with the bottom end surface of the second shell (6), and a second valve (9) is arranged on the discharge pipe.

9. The system for removing silicon powder from exhaust gas according to claim 8, wherein the bottom of the second shell (6) is conical, and the conical bottom is used for gathering silicon powder.

10. The system for removing silicon powder from exhaust gas according to claim 9, wherein a second heater is arranged in the bottom of the second shell (6).

11. The system for removing silicon powder from tail gas according to claim 8, wherein the collecting device further comprises a third casing (7), the third casing is located above the second casing (6) and is communicated with the second casing (6), a second filter element (8) is arranged in the third casing (7), the second filter element (8) is used for blocking silicon powder in tail gas from the first casing (1), and an outlet is arranged at the top of the third casing and is used for discharging the tail gas filtered by the second filter element (8).

12. The system for removing silicon powder from tail gas according to claim 8, wherein the bottom of the second housing (6) is further provided with an inlet, and replacement gas enters the second housing (6) from the inlet, so that the tail gas in the second housing (6) is forced to exit after passing through the second filter element (8).

13. The system for removing silicon powder from exhaust gas according to claim 12, wherein the displacement gas is nitrogen.

Technical Field

The invention relates to the field of polycrystalline silicon production, in particular to a system for removing silicon powder in tail gas.

Background

Tail gas doped with silicon powder is generated in the production of polycrystalline silicon. The tail gas comprises the following components: chlorosilane, hydrogen chloride, and hydrogen. If silicon powder enters a subsequent tail gas treatment system along with tail gas, the silicon powder is likely to block a tail gas pipeline, so that the production efficiency is reduced. In addition, the direct discharge of the silicon powder causes waste of the silicon powder.

Therefore, how to design a system for removing silicon powder from the tail gas, which can remove the silicon powder from the tail gas and collect the silicon powder, is a key problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The invention aims to provide a system for removing silicon powder in tail gas, which can remove the silicon powder in the tail gas and collect the silicon powder. In order to achieve the purpose, the invention provides the following technical scheme:

a system for removing silicon powder in tail gas comprises a filtering device and a collecting device, wherein the filtering device is used for filtering the silicon powder in the tail gas out, and the collecting device is used for collecting the silicon powder filtered out by the filtering device; the filter device with communicate through communicating pipe between the collection device, be provided with first valve on communicating pipe, first valve is used for controlling switching on and closing of communicating pipe.

Preferably, the first valve is controlled by a controller, and the controller controls the opening and closing of the first valve according to a set time value.

Preferably, the filtering device comprises a first shell, a first filter element is arranged in the first shell, and the first filter element is used for blocking silicon powder;

the first shell is provided with an inlet and an outlet, the inlet is located below the first filter element, the outlet is located above the first filter element, tail gas enters the first shell from the inlet, and flows out from the outlet after being filtered by the first filter element.

Preferably, the filtering device further comprises a purging device, the purging device is used for blowing off the silicon powder on the first filter element, and a purging port of the purging device is located above the first filter element.

Preferably, the tail gas filtered by the first filter element is condensed by a condenser, and the separated hydrogen enters the purging device.

Preferably, the bottom of the first shell is conical, and the conical bottom is used for gathering silicon powder.

Preferably, a first heater is disposed in a bottom portion of the first housing.

Preferably, the collecting device comprises a second shell, the second shell is communicated with the first shell through the communicating pipe, the bottom end face of the second shell is communicated with a discharge pipe, and a second valve is arranged on the discharge pipe.

Preferably, the bottom of the second shell is conical, and the conical bottom is used for gathering silicon powder.

Preferably, a second heater is disposed in a bottom of the second housing.

Preferably, the collecting device further comprises a third casing, the third casing is located above the second casing, the third casing is communicated with the second casing, a second filter element is arranged in the third casing, the second filter element is used for blocking silicon powder in tail gas, the tail gas comes from the first casing, an outlet is formed in the top of the third casing, and the outlet is used for discharging the tail gas filtered by the second filter element.

Preferably, the bottom of the second casing is further provided with an inlet, and replacement gas enters the second casing from the inlet to force tail gas in the second casing to pass through the second filter element and then be discharged.

Preferably, the displacement gas is nitrogen.

According to the technical scheme, the tail gas containing chlorosilane, hydrogen chloride and hydrogen is introduced into the filtering device, and the filtering device filters silicon powder in the tail gas, so that the separation of the silicon powder from the chlorosilane, the hydrogen chloride and the hydrogen is realized. And then, a first valve on the communicating pipe is opened, so that the filtered silicon powder enters a collecting device through the communicating pipe, and the collection of the silicon powder is realized. The system disclosed by the invention not only can filter the silicon powder in the tail gas so as to avoid the blockage of the tail gas pipeline by the silicon powder, but also can collect the filtered silicon powder so as to realize the reutilization of the silicon powder.

Drawings

In order to more clearly illustrate the solution of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of a system for removing silicon powder from an exhaust gas according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a filtering apparatus according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a collecting device according to an embodiment of the present invention.

Wherein, 1 is the first casing, 2 is the first filter core, 3 is the export on the first casing, 4 is first valve, 5 is communicating pipe, 6 is the second casing, 7 is the third casing, 8 is the second filter core, 9 is the second valve, 10 is the first differential pressure table, 11 is the second differential pressure table.

Detailed Description

The invention discloses a system for removing silicon powder in tail gas, which can remove the silicon powder in the tail gas and collect the silicon powder.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

In the invention, the system for removing the silicon powder in the tail gas comprises a filtering device and a collecting device. The filtering device is used for filtering silicon powder in the tail gas. The collecting device is used for collecting the silicon powder filtered by the filtering device. The filtering device is communicated with the collecting device through a communicating pipe 5. And the communicating pipe 5 is provided with a first valve 4. The first valve 4 is used for controlling the connection and disconnection of the communicating pipe 5. In practical applications, the first valve 4 may be opened once every set time.

In particular, the first valve 4 may be controlled by a controller. The controller is internally provided with a timer. When the timer counts to a set value, the controller controls the first valve 4 to be opened.

Referring to fig. 1 and 2, the filter device specifically includes a first housing 1 and a first filter element 2. The first filter element 2 is disposed inside the first housing 1. The first filter element 2 is used for blocking silicon powder in tail gas. The first housing 1 is provided with an inlet and an outlet 3. And the inlet is located below the first filter element 2 and the outlet 3 is located above the first filter element 2. When entering the first housing 1 through the inlet, the exhaust gas moves upward through the first filter element 2. In the process, silicon powder in the tail gas is adsorbed on the first filter element 2, and the tail gas after passing flows out from the outlet 3.

It should be noted that a first pressure difference meter 10 may be further provided, and the first pressure difference meter 10 is used for measuring the pressure difference between the air inlet and the air outlet of the first filter element 2. The pressure difference is used for representing the content of the filtered silicon powder, so that the working condition of the first filter element 2 can be conveniently and timely mastered by a worker.

With continued reference to fig. 1 and 2, the filtration apparatus further includes a purging device. The blowing equipment is used for blowing air to the first filter element 2 so as to blow off the silicon powder on the first filter element 2. It should be noted that the purging port of the purging device is located above the first filter element 2, that is, the purging device blows from top to bottom, so that the silicon powder on the first filter element 2 directly falls into the bottom of the first housing 1.

The purge device was purged with hydrogen. The hydrogen comes from the tail gas filtered by the first filter element 2. The tail gas filtered by the first filter element 2 contains chlorosilane, hydrogen chloride and hydrogen. And then introducing the tail gas into a condenser, liquefying chlorosilane under the action of the condenser, and dissolving hydrogen chloride in chlorosilane liquid. Gaseous hydrogen is separated off and then passed to a purge device. Thus, no extra purge gas is introduced, thereby saving energy.

Further, the bottom of the first housing 1 is tapered. The conical bottom provides for the collection of silicon powder. Namely, the silicon powder adsorbed on the first filter element 2 falls into the bottom of the first shell 1 after being blown by the blowing equipment. Since the bottom of the first housing 1 is a slope, the silicon powder slides down the slope and is gathered together. In this way, after the first valve 4 is opened, the silicon powder can smoothly slide into the communicating pipe 5.

In addition, a first heater is provided at the bottom of the first casing 1. The first heater is used for heating the first shell 1 to prevent chlorosilane in the tail gas from condensing, thereby causing agglomeration of silicon powder. The first heater may be specifically an inductor, or a heating oil or a heat exchanger, and the form of the first heater is not particularly limited as long as heat can be provided to the first housing 1 and the filtering and collecting of the silicon powder can be ensured, which falls into the protection scope of the present disclosure.

Please refer to fig. 1 and fig. 3. The collecting device comprises a second housing 6. The second housing 6 and the first housing 1 communicate through the communication pipe 5. The bottom end surface of the second casing 6 is communicated with a discharge pipe. The discharge pipe is provided with a second valve 9. That is, the silicon powder accumulated at the bottom of the first casing 1 enters the second casing 6 through the communication pipe 5 in a state where the first valve 4 is opened, and the silicon powder is discharged from the discharge pipe in a state where the second valve 9 is opened. Since the communication pipe 5 is provided below the first housing 1 and the discharge pipe is provided below the second housing 6, discharge of the silicon powder is facilitated.

Note that, similarly to the bottom shape of the first casing 1, the bottom shape of the second casing 6 is also tapered. The conical bottom part is used for gathering the silicon powder, thereby being beneficial to discharging the silicon powder. In addition, the second heater is arranged at the bottom of the second shell 6, and the second heater has the same function as the first heater, and the function of the second heater is to heat the second shell 6 so as to prevent the silicon powder in the second shell 6 from caking. It should be further noted that, at the initial stage of the conduction of the first valve 4, the pressure in the second housing 6 is lower than the pressure in the first housing 1, so that while the silicon powder enters the second housing 6 through the communication pipe 5, the tail gas in the first housing 1 also enters the second housing 6 through the communication pipe 5. Therefore, a second heater is arranged in the second shell 6 to prevent condensation of chlorosilane in the tail gas, so that silicon powder is agglomerated and is not beneficial to discharge. The second heater is preferably disposed near the bottom of the second housing 6 because the silicon powder collects at the bottom of the second housing 6.

With continued reference to fig. 1 and 3, the collecting device further comprises a third housing 7. The third casing 7 is located above the second casing 6. And the third housing 7 communicates with the second housing 6. A second filter element 8 is arranged in the third shell 7. The second filter element 8 is used for blocking silicon powder in the tail gas entering the second shell 6. The top of the third casing 7 is provided with an outlet for discharging the tail gas filtered by the second filter element 8. The part of tail gas enters an exhaust gas leaching system after being discharged.

It should be noted that a second pressure difference meter 11 may be further provided, and the second pressure difference meter 11 is used for measuring the pressure difference between the air inlet and the air outlet of the second filter element 8. The pressure difference is used for representing the content of the filtered silicon powder, so that the working condition of the second filter element 8 can be conveniently and timely mastered by a worker.

Further, an inlet is provided at the bottom of the second housing 6. The displacement gas enters the second housing 6 from the inlet, and the exhaust gas in the second housing 6 is forced to pass through the second filter element 8 and then is discharged. Therefore, chlorosilane in the silicon powder can be removed, and the purity of the silicon powder is improved. Preferably, the replacement gas is set to nitrogen.

In summary, the working process of the system for removing silicon powder from tail gas in the invention is as follows: the tail gas containing chlorosilane, hydrogen chloride and hydrogen enters the first shell 1, and then moves upwards to pass through the first filter element 2. Silica flour adsorbs on first filter core 2, and the tail gas that contains chlorosilane, hydrogen chloride and hydrogen flows out from first casing 1, and then flows into in the condenser. In the condenser, chlorosilane is condensed and liquefied, and hydrogen chloride is dissolved in a chlorosilane solution. Gaseous hydrogen is separated out and passed to a purge device. The blowing device is used for blowing air to the first filter element 2 and blowing the silicon powder on the first filter element 2 to the conical bottom of the first shell 1. After the set time is reached, the controller controls the first valve 4 to be opened, the silicon powder in the first shell 1 enters the second shell 6 through the communicating pipe 5, and the silicon powder entering the second shell 6 also contains tail gas. Then the first valve 4 is closed, and nitrogen is introduced into the second casing 6 through the inlet on the second casing 6, and the nitrogen forces the tail gas to move upwards and is discharged after being filtered by the second filter element 8. The silicon powder in the second shell 6 gradually gathers to the bottom of the second shell 6, and finally the second valve 9 is opened to discharge the silicon powder in the second shell 6 from the discharge pipe.

Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.