CN212262801U - Polycrystalline silicon production waste gas treatment system - Google Patents
Polycrystalline silicon production waste gas treatment system Download PDFInfo
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- CN212262801U CN212262801U CN201922389219.6U CN201922389219U CN212262801U CN 212262801 U CN212262801 U CN 212262801U CN 201922389219 U CN201922389219 U CN 201922389219U CN 212262801 U CN212262801 U CN 212262801U
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Abstract
The utility model discloses a polycrystalline silicon production exhaust treatment system, include: a first exhaust buffer tank connected to the exhaust gas discharge pipe; the adsorption tower is connected with the output end of the first waste gas buffer tank; wherein, be provided with the adsorption column in the adsorption tower, it has active carbon to fill in the adsorption column, the adsorption tower passes through active carbon will chlorosilane in the exhaust gas discharge pipeline output waste gas adsorbs. Through filling the silane in the active carbon absorption waste gas in adopting the adsorption tower, replace traditional waste gas drip washing and handling, because waste gas must all pass through the active carbon, make can fully contact fully absorbed, when guaranteeing that waste gas hundred reaches standard discharges, because what whole processing procedure adopted is physical treatment method, chemical reaction can not take place, the thermal production that has reduced and the input of chemical and follow-up processing to chlorine-containing waste water, adsorbed silane can also be retrieved, environmental risk has been reduced when increasing the income.
Description
Technical Field
The utility model relates to a waste gas treatment technical field, more specifically say, relate to a polycrystalline silicon production exhaust-gas treatment system.
Background
Due to the continuous development of photovoltaic technology, the market share of power generation by using polysilicon batteries is getting larger and larger due to low cost and relatively high efficiency. While the improvement of the power generation efficiency is more limited, the low-cost polycrystalline silicon is also an important way for reducing the photovoltaic cells.
A large amount of waste gas is generated in the production process of the polycrystalline silicon, and the generated waste gas mainly comprises nitrogen, hydrogen, silicon tetrachloride, trichlorosilane, dichlorosilane, hydrogen chloride and trace silicon powder. At present, the waste gas treatment mode in the polysilicon industry is mainly treated in a leaching mode, water is used for reacting with chlorosilane, hydrogen chloride is absorbed at the same time, harmful gas in the waste gas is removed, and the residual nitrogen and hydrogen are discharged to the atmosphere at a high point.
However, the treatment of the exhaust gas by the leaching method has the following problems:
1. chlorosilane in the waste gas cannot be recovered, so that material waste is caused;
2. the waste water after the leaching also needs downstream sewage treatment and high-salinity waste water treatment, so that the water treatment cost is increased;
3. the waste gas is leached, so that the harmful substances cannot be removed by 100 percent, and the emission after reaching the standard is difficult to achieve.
SUMMERY OF THE UTILITY MODEL
The utility model provides a polycrystalline silicon production exhaust treatment system realizes that exhaust emission is up to standard, reduces the exhaust-gas treatment cost.
In order to solve the above technical problem, an embodiment of the present invention provides a polysilicon production waste gas treatment system, including:
a first exhaust buffer tank connected to the exhaust gas discharge pipe;
the adsorption tower is connected with the output end of the first waste gas buffer tank;
the adsorption tower is internally provided with an adsorption column filled with active carbon, and the adsorption tower adsorbs chlorosilane in the waste gas output by the waste gas discharge pipeline through the active carbon;
the system also comprises a waste gas compressor which is arranged between the first waste gas buffer tank and the input end of the adsorption tower and is used for pressurizing the first waste gas buffer tank to a preset pressure and then outputting the pressurized first waste gas buffer tank to the adsorption tower;
the second waste gas buffer tank is arranged between the waste gas compressor and the input end of the adsorption tower; the waste gas treatment device is characterized by further comprising a pressure regulating valve arranged between the first waste gas buffer tank and the second waste gas buffer tank and used for regulating the air pressure in the first waste gas buffer tank.
The system comprises an exhaust gas compressor, a second exhaust gas buffer tank, a first exhaust gas cooler, a second exhaust gas buffer tank and a second exhaust gas cooler, wherein the first exhaust gas cooler is arranged between the exhaust gas compressor and the second exhaust gas buffer tank and used for cooling the exhaust gas output by the exhaust gas compressor and then outputting the cooled exhaust gas to the second exhaust gas buffer tank.
The adsorption tower is characterized by further comprising a second waste gas cooler arranged between the second waste gas buffer tank and the adsorption tower and used for cooling the waste gas output by the second waste gas buffer tank and then outputting the cooled waste gas to the adsorption tower.
Wherein, the device also comprises a standby adsorption tower which is connected with the adsorption tower in parallel.
The system also comprises a condensate buffer tank connected with the first exhaust gas cooler and the second exhaust gas cooler.
The liquid level control system comprises a condensate buffer tank, a liquid level regulating valve, a liquid level control device and a rectification device, wherein the rectification device is connected with the condensate buffer tank through the condensate conveying pump and the liquid level regulating valve, the condensate conveying pump is used for conveying condensate in the condensate buffer tank to the rectification device, and the liquid level regulating valve is used for controlling the flow of the condensate in the rectification device to the condensate buffer tank to control the liquid level of the condensate buffer tank.
The device comprises a standby adsorption tower, an adsorption tower and a tail gas recovery device, wherein the standby adsorption tower is connected with the adsorption tower, the adsorption tower is connected with the desorption device, the standby adsorption tower is controlled to work, the standby adsorption tower or the adsorption tower is in a non-working state to be desorbed, and the desorbed gas is output and recovered through the tail gas recovery device.
Compared with the prior art, the embodiment of the utility model provides a polycrystalline silicon production waste gas treatment system has following beneficial effect:
the embodiment of the utility model provides a polycrystalline silicon production exhaust treatment system, through adopting the silane that fills in the active carbon absorption waste gas in the adsorption tower, replace traditional waste gas and spray the processing, because waste gas must all pass through the active carbon, make and fully contact fully absorbed, when guaranteeing that waste gas hundredth is up to standard, because what whole processing procedure adopted is physical treatment method, chemical reaction can not take place, the thermal production that has reduced and the input of chemical and follow-up processing to chlorine-containing waste water, adsorbed silane can also be retrieved, the environmental risk has been reduced when increasing the income.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an embodiment of a system for treating waste gas from polysilicon production according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a desorption part of an adsorption tower in an embodiment of a system for treating waste gas from polysilicon production provided in an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
As shown in fig. 1-2, fig. 1 is a schematic structural diagram of an embodiment of a polysilicon production waste gas treatment system provided in the embodiment of the present application; fig. 2 is a schematic structural diagram of a desorption part of an adsorption tower in an embodiment of a system for treating waste gas from polysilicon production provided in an embodiment of the present application.
In a specific embodiment, the utility model provides a polycrystalline silicon production waste gas treatment system, includes:
a first exhaust buffer tank 10 connected to the exhaust gas discharge pipe;
an adsorption tower 20 connected to an output end of the first exhaust gas buffer tank 10;
wherein, be provided with the adsorption column in the adsorption tower 20, it has active carbon to fill in the adsorption column, adsorption tower 20 passes through active carbon will chlorosilane absorption in the exhaust gas discharge pipeline output waste gas.
Polycrystalline silicon production exhaust treatment system, through adopting filling the silane in the active carbon absorption waste gas in the adsorption tower 20, replace traditional waste gas and spray the processing, because waste gas must all pass through the active carbon, make can fully contact fully absorbed, when guaranteeing that waste gas hundredth is up to standard, because what whole processing procedure adopted is the physical treatment method, chemical reaction can not take place, the production of the heat that has reduced and the input of chemical and follow-up processing to chlorine-containing waste water, adsorbed silane can also be retrieved, the environmental risk has been reduced when increasing the income.
The utility model provides a polycrystalline silicon production exhaust gas treatment system makes after waste gas output through setting up the buffer tank, can not cause the waste gas that reachs adsorption tower 20 because atmospheric pressure unstability and rapid change because of the change of the output flow of waste gas in the exhaust gas discharge pipeline to play the effect of buffering. The utility model discloses do not do the injecing to shape, size and the material of buffer tank, do not do the injecing to the position of its waste gas input and output, generally because the density of waste gas is big than the air, sets up the input in the bottom, sets up the output at the top, and the interval of the two is as big as possible, just so can realize abundant buffering.
Since it may be practical to lower the gas pressure in the first buffer tank during operation, in which the content of silane is small, and the treatment efficiency at normal pressure is low, in order to improve the treatment efficiency, in one embodiment, the polysilicon production off-gas treatment system further includes an off-gas compressor 30 disposed between the first off-gas buffer tank 10 and the input end of the adsorption tower 20, for pressurizing the first off-gas buffer tank 10 to a predetermined pressure and then outputting to the adsorption tower 20.
The waste gas is pressurized and compressed by the waste gas compressor 30, so that the content of the pretreatment gas in unit volume is increased, the pretreatment gas can be quickly and fully contacted when being treated by the adsorption tower 20, and the contact proportion is increased. For example, the contact adsorption of silane per unit time per unit volume of activated carbon in the adsorption column 20 is 0.1 before the compression treatment, and the contact adsorption of silane per unit time can be 0.5 or more within the treatment range after the compression treatment, thereby improving the treatment efficiency.
The utility model discloses do not do the injecing to the compression ratio of exhaust gas compressor 30 and the compressive capacity of unit interval, can adopt a compressor 30 to handle, also can adopt many compressors 30 to circulate and handle, the utility model discloses do not do the injecing to this.
Also, since the off-gas is released in a short time after the compression of the off-gas is completed, in order to achieve the off-gas buffering, the system for treating the off-gas in the polysilicon production typically further includes a second off-gas buffer tank 40 disposed between the off-gas compressor 30 and the input end of the adsorption tower 20.
The utility model discloses in do not do the injecing to size, shape etc. of second waste gas buffer tank 40, because it is through the waste gas of compression, therefore the volume is less relatively, can adopt the buffer tank of volume less than first waste gas buffer tank 10, perhaps the two adopts the buffer tank of same model, can be through the governing valve 120 controlled pressure constant voltage of adsorption tower 20 output, realize exporting the waste gas pressure of adsorption tower 20 and keep stable, realize the steady operation of whole device.
To solve the problem that the first pressure fluctuates because the gas pressures of the first and second waste gas buffer tanks 10 and 40 are not equal to each other because the flow rate of the front-end incoming waste gas is constantly changing and the pumping amount of the compressor is generally stable, in one embodiment, the polysilicon production waste gas treatment system further includes a pressure regulating valve 50 disposed between the first and second waste gas buffer tanks 10 and 40 for regulating the pressure in the first waste gas buffer tank 40.
Through set up air-vent valve 50 between the two, when needs carry out pressure adjustment, open and to make the great party of atmospheric pressure carry out the pressure release to make first buffer tank 40 pressure remain stable, make exhaust-gas treatment more stable high-efficient, improve the operational reliability of device.
Because the gas pressure and internal energy are increased in the waste gas compression process, the temperature inside the waste gas compression process is increased, and the temperature is too high, which is not beneficial to the subsequent activated carbon adsorption of the adsorption tower 20, in one embodiment, the polycrystalline silicon production waste gas treatment system further comprises a first waste gas cooler 60 arranged between the waste gas compressor 30 and the second waste gas buffer tank 40, and used for cooling the waste gas output by the waste gas compressor 30 and then outputting the cooled waste gas to the second waste gas buffer tank 40.
Through the waste gas cooling after first exhaust gas cooler 60 will compress, make compressor 30 etc. be in lower operating temperature on the one hand, temperature continues to rise and causes the incident when avoiding continuing to compress next time, and on the other hand also makes the temperature of waste gas obtain descending for the active carbon in adsorption tower 20 can not be heated or overheated and reduce its adsorption efficiency, thereby improves exhaust-gas treatment efficiency.
The chlorosilane content in the waste gas is high, so that the adsorption capacity of the adsorption column is influenced, and the saturation can be easily achieved in unit time. In order to improve the adsorption capacity of the adsorption column, the polysilicon production waste gas treatment system further comprises a second waste gas cooler 70 arranged between the second waste gas buffer tank 40 and the adsorption tower 20, and is used for condensing and recovering part of chlorosilane in waste gas output by the second waste gas buffer tank 40, so that the content of chlorosilane in the waste gas is reduced, and the waste gas is cooled and then enters the adsorption tower 20, so that the treatment capacity of the adsorption column is improved.
Since the adsorption amount of the activated carbon in the adsorption tower 20 is not infinite, after adsorption for a certain period of time, the activated carbon may be saturated to cause a reduction in treatment capacity or a loss of waste gas adsorption capacity, and waste gas is continuously generated, which may affect the normal safe production process, and this situation may be solved by filling a sufficient amount of activated carbon at a time, as long as a shift of production task is completed, and the activated carbon is unloaded and refilled with new activated carbon, but on one hand, the workload caused by loading and unloading of activated carbon is large, and on the other hand, if the adsorption tower 20 fails, a shutdown is required, and in order to solve this technical problem, in an embodiment of the present invention, the polysilicon production waste gas treatment system further includes a spare adsorption tower 20 connected in parallel with the adsorption tower 20.
Through parallelly connected reserve adsorption tower 20, form the relation of reserve each other with original adsorption tower 20, after one of them completion adsorbs or the work is unusual, directly switch over to do not influence current duty cycle, improve work efficiency.
In order to solve the problem that a cooling effect may be reduced if a treatment cannot be performed due to the generation of a high-temperature coolant during the cooling of the exhaust gas, the system for treating the exhaust gas from the production of polycrystalline silicon further includes a condensate buffer tank 80 connected to the first and second exhaust gas coolers 60 and 70.
Through condensate buffer tank 80, retrieve the coolant liquid, carry lower cryogenic coolant liquid simultaneously, realize high-efficient cooling, thereby also can dispel the heat fast in condensate buffer tank 80 and reduce the temperature. And some substances in the silane are liquid at low temperature, for example, tetrachlorosilane is liquid at room temperature, and can be primarily recovered, so that the adsorption amount of the activated carbon in the adsorption tower 20 is reduced, and the working time of the adsorption tower is prolonged.
In order to solve the technical problem that the required amount of the cooling liquid may change along with the change of time, the insufficient or excessive cooling liquid in the condensate buffer tank 80 may occur, in an embodiment of the present invention, the system for treating waste gas from polysilicon production further comprises a rectifying device 110 connected to the condensate buffer tank 80 through a condensate transfer pump 90 and a level regulating valve 100, wherein the condensate transfer pump is used for transferring the condensate in the condensate buffer tank 80 to the rectifying device, and the level regulating valve is used for controlling the flow rate of the condensate flowing to the condensate buffer tank 80 by the rectifying device to control the liquid level of the condensate buffer tank 80.
By connecting the rectifying device 110, when the cooling liquid is too much, the condensate transfer pump 90 transfers the condensate in the condensate buffer tank 80 to the rectifying device 110, and when the cooling liquid is too little, the liquid level regulating valve 100 controls the flow rate of the condensate flowing from the rectifying device 110 to the condensate buffer tank 80 to control the liquid level of the condensate buffer tank 80, so that the liquid level height of the cooling liquid in the condensate buffer tank 80 has small change whenever.
Since the silane in the exhaust gas adsorbed by the activated carbon can be used continuously to obtain economic efficiency, in one embodiment, the polysilicon production exhaust gas treatment system further includes a desorption device connected to the spare adsorption tower 20 and the adsorption tower 20, and configured to control the working states of the spare adsorption tower 20 and the adsorption tower 20, and to desorb the spare adsorption tower 20 or the adsorption tower 20 in a non-working state, and output desorption gas and recover the desorption gas through a tail gas recovery device.
The adsorbed waste gas is analyzed by the analysis device, so that the waste gas can be recycled, and the silane adsorbed by the activated carbon can be analyzed, so that the adsorption capacity can be recovered.
The whole waste gas treatment process is as follows:
waste gas from a waste gas discharge pipeline of a whole plant enters a first waste gas buffer tank 10 and is pressurized by a waste gas compressor 30, the pressurized waste gas is cooled by a first waste gas cooler 60, the cooled waste gas enters a second waste gas buffer tank 40, the pressure of the second waste gas buffer tank 40 is adjusted by a waste gas buffer tank pressure adjusting valve 50, condensate condensed by the first waste gas cooler 60 enters a condensate buffer tank 80, the pressurized waste gas enters a second waste gas cooler 70 for recondensation to recover chlorosilane in the waste gas, the second waste gas cooler 70 enters the condensate buffer tank 80, the deep-cooled waste gas enters a waste gas adsorption column of an adsorption tower 20, the adsorption column is filled with active carbon, residual chlorosilane in the waste gas is adsorbed by the active carbon, and the adsorbed waste gas is discharged to the atmosphere by the waste gas adjusting valve; when the adsorption column works for a certain time, the adsorption state needs to be switched to an analytic state, hydrogen is heated by a hydrogen heater 201, the flow is controlled by a purge gas regulating valve 202 to purge and regenerate the adsorption column which is saturated in adsorption, and analytic gas is cooled by an analytic gas cooler 203 and then is sent to a tail gas recovery system for recovery; the condensate in the condensate buffer tank is delivered to the rectifying device 110 by the condensate delivery pump 90, and the liquid level of the condensate buffer tank 80 is controlled by the liquid level regulating valve 100.
To sum up, the embodiment of the utility model provides a polycrystalline silicon production exhaust treatment system, through adopting the silane that fills in the active carbon absorption waste gas in the adsorption tower, replace traditional waste gas and spray the processing, because waste gas must all pass through the active carbon, make and fully contact by the absorption, when guaranteeing that waste gas hundredth is up to standard, because what whole processing procedure adopted is physical treatment method, chemical reaction can not take place, the thermal production that has reduced and the input of chemical and follow-up processing to chlorine-containing waste water, adsorbed silane can also be retrieved, the environmental risk has been reduced when increasing the income.
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.
Claims (6)
1. A polysilicon production waste gas treatment system, comprising:
a first exhaust buffer tank connected to the exhaust gas discharge pipe;
the adsorption tower is connected with the output end of the first waste gas buffer tank;
the adsorption tower is internally provided with an adsorption column filled with active carbon, and the adsorption tower adsorbs chlorosilane in the waste gas output by the waste gas discharge pipeline through the active carbon;
the system also comprises a waste gas compressor which is arranged between the first waste gas buffer tank and the input end of the adsorption tower and is used for pressurizing the first waste gas buffer tank to a preset pressure and then outputting the pressurized first waste gas buffer tank to the adsorption tower;
the second waste gas buffer tank is arranged between the waste gas compressor and the input end of the adsorption tower; the waste gas treatment device is characterized by further comprising a pressure regulating valve arranged between the first waste gas buffer tank and the second waste gas buffer tank and used for regulating the air pressure in the first waste gas buffer tank.
2. The polysilicon production waste gas treatment system according to claim 1, further comprising a first waste gas cooler disposed between the waste gas compressor and the second waste gas buffer tank, for cooling the waste gas output from the waste gas compressor and outputting the cooled waste gas to the second waste gas buffer tank.
3. The polysilicon production waste gas treatment system according to claim 2, further comprising a second waste gas cooler disposed between the second waste gas buffer tank and the adsorption tower, for cooling the waste gas output from the second waste gas buffer tank and outputting the cooled waste gas to the adsorption tower.
4. The system for treating the off-gas in the production of polycrystalline silicon according to claim 3, further comprising a backup adsorption tower connected in parallel with the adsorption tower.
5. The polysilicon production waste gas treatment system of claim 4, further comprising a condensate buffer tank connected to the first waste gas cooler and the second waste gas cooler.
6. The polysilicon production waste gas treatment system as set forth in claim 5, further comprising a rectifying device connected to the condensate buffer tank via a condensate transfer pump for transferring the condensate in the condensate buffer tank to the rectifying device and a level regulating valve for controlling the flow rate of the condensate flowing from the rectifying device to the condensate buffer tank to control the liquid level of the condensate buffer tank.
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| CN201922389219.6U CN212262801U (en) | 2019-12-26 | 2019-12-26 | Polycrystalline silicon production waste gas treatment system |
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| CN201922389219.6U CN212262801U (en) | 2019-12-26 | 2019-12-26 | Polycrystalline silicon production waste gas treatment system |
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| CN212262801U true CN212262801U (en) | 2021-01-01 |
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| CN201922389219.6U Active CN212262801U (en) | 2019-12-26 | 2019-12-26 | Polycrystalline silicon production waste gas treatment system |
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