A cold hydrogenation reaction device and polysilicon production system

Abstract

The utility model discloses a cold hydrogenation reaction device and a polysilicon production system, wherein the cold hydrogenation reaction device comprises a vaporization unit, a filtering unit, and a slurry separation unit; the filtering unit comprises a liquid phase filter, the liquid phase inlet of the liquid phase filter is connected to the residual discharge outlet of the vaporization unit, and the filter residue outlet of the liquid phase filter is connected to the filter residue inlet of the slurry separation unit. The cold hydrogenation reaction device provided by the utility model has the characteristic of low energy consumption.

Description

Technical Field

[0001] The utility model relates to a cold hydrogenation reaction device and a polysilicon production system, belonging to the field of applied chemical industry. Background Art

[0002] In the cold hydrogenation process, hydrogen and silicon tetrachloride are mixed and heat exchanged, then vaporized together in a silicon tetrachloride vaporizer, and then heated, and then enter the fluidized bed to react with silicon powder to obtain the product trichlorosilane. The silicon tetrachloride entering the silicon tetrachloride vaporizer often contains a small amount of silicon powder, which will be deposited in the silicon tetrachloride vaporizer and cause wear and penetration of the tube bundle. Therefore, it is necessary to discharge part of the silicon tetrachloride containing silicon powder to the quenching tower through the residual discharge step, and then mix it with the chlorosilane used for elution in the quenching tower and enter the slurry separation equipment. The separation equipment can separate the silicon tetrachloride, and the obtained silicon tetrachloride re-enters the silicon tetrachloride vaporizer for cold hydrogenation reaction.

[0003] At present, the silicon tetrachloride discharged from the residual discharge step accounts for about 3% of the feed amount of the silicon tetrachloride vaporizer. This part of the residual silicon tetrachloride causes a high workload of the slurry separation equipment and high energy consumption.

[0004] Therefore, how to reduce the workload of slurry separation equipment and reduce energy consumption has become a research direction in this field. Utility Model Content

[0005] The utility model provides a cold hydrogenation reaction device which has the characteristics of less energy consumption.

[0006] The utility model also provides a polysilicon production system, which has the characteristic of low operating cost.

[0007] The utility model provides a cold hydrogenation reaction device, which includes a vaporization unit, a filtering unit, and a slurry separation unit;

[0008] The filtering unit comprises a liquid phase filter, a liquid phase inlet of the liquid phase filter is communicated with a residue discharge outlet of the vaporization unit, and a filter residue outlet of the liquid phase filter is communicated with a filter residue inlet of the slurry separation unit.

[0009] The device as described above, wherein it further comprises a silicon tetrachloride storage unit, and the filtrate outlet of the liquid phase filter is connected to the liquid phase inlet of the silicon tetrachloride storage unit.

[0010] The device as described above, wherein it further comprises a hydrogen supply unit and a preheating unit, and the liquid phase outlet of the silicon tetrachloride storage unit and the hydrogen outlet of the hydrogen supply unit are connected to the logistics inlet of the vaporization unit through the preheating unit.

[0011] The device as described above, wherein it further comprises a heat exchange unit, and the liquid phase outlet of the liquid phase filter is connected to the liquid phase inlet of the silicon tetrachloride storage unit through the heat exchange unit.

[0012] The device as described above, wherein, further comprises a distillation unit and a hydrolysis unit, wherein the liquid phase inlet of the distillation unit is communicated with the liquid phase outlet of the slurry separation unit, and the logistics inlet of the hydrolysis unit is communicated with the solid phase outlet of the slurry separation unit.

[0013] The device as described above, wherein the silicon tetrachloride outlet of the distillation unit is communicated with the liquid phase inlet of the silicon tetrachloride storage unit.

[0014] The device as described above, wherein the liquid phase filter includes a filter chamber with a filter element inside, and a filtrate chamber connected to the filter chamber for receiving filtrate, and the filtration unit also includes a first pressure gauge and a second pressure gauge, the first pressure gauge is connected to the filter chamber, and the second pressure gauge is connected to the filtrate chamber.

[0015] The device as described above, wherein it comprises N filtering units, N ≥ 1;

[0016] When N>1, N filtering units are connected in parallel.

[0017] The device as described above, wherein N=2, and the working states of the first filter unit and the second filter unit are opposite;

[0018] Wherein, the liquid phase outlet of the liquid phase filter of the first filter unit is also connected to the filter cavity of the second filter unit, and the liquid phase outlet of the liquid phase filter of the second filter unit is also connected to the filter cavity of the first filter unit;

[0019] The first filter unit further includes a first buffer tank, and the liquid phase outlet of the liquid phase filter of the first filter unit is connected to the filter cavity of the second filter unit through the first buffer tank;

[0020] The second filter unit includes a second buffer tank, and the liquid phase outlet of the liquid phase filter of the second filter unit is connected with the filter cavity of the first filter unit through the second buffer tank.

[0021] The utility model also provides a polysilicon production system, which comprises any one of the above-mentioned cold hydrogenation reaction devices.

[0022] The cold hydrogenation reaction device provided by the utility model has the characteristic of less energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced one by one below. Obviously, the drawings in the following description are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 A schematic diagram of the structure of a cold hydrogenation reaction device provided by the utility model;

[0025] Figure 2 A schematic diagram of a cold hydrogenation reaction device provided by the utility model;

[0026] Figure 3 Schematic diagram of the equipment of the cold hydrogenation reaction device used in the comparative example.

[0027] Description of reference numerals:

[0028] A-first filter unit;

[0029] A101-first liquid phase filter chamber;

[0030] A102 - first liquid phase filter filtrate chamber;

[0031] A103-first liquid phase filter first pressure gauge;

[0032] A104-first liquid phase filter second pressure gauge;

[0033] A2-first buffer tank;

[0034] A3-first control valve;

[0035] A4-third control valve;

[0036] B-second filter unit;

[0037] B101- second liquid phase filter chamber;

[0038] B102-second liquid phase filter filtrate chamber;

[0039] B103-the first pressure gauge of the second liquid phase filter;

[0040] B104-second liquid phase filter second pressure gauge;

[0041] B2-second buffer tank;

[0042] B3-second control valve;

[0043] B4-fourth control valve;

[0044] C-vaporization unit;

[0045] C1-silicon tetrachloride vaporizer;

[0046] D-slurry separation unit;

[0047] D1-slurry buffer tank;

[0048] D2-slurry separator;

[0049] E-silicon tetrachloride storage unit;

[0050] E1-Silicon tetrachloride storage tank;

[0051] E2-fifth control valve;

[0052] F-hydrogen supply unit;

[0053] F1-raw hydrogen interface;

[0054] G-preheating unit;

[0055] G1-static mixer;

[0056] G2-preheater;

[0057] H-heat exchange unit;

[0058] H1-heat exchanger;

[0059] I-distillation unit;

[0060] I1-distillation column;

[0061] J-hydrolysis unit;

[0062] J1-hydrolysis tank;

[0063] K-cold hydrogenation reaction unit;

[0064] K1-cold hydrogenation reactor;

[0065] L-quenching unit;

[0066] L1-quenching tower and condensing equipment;

[0067] M-raw material heating unit;

[0068] M1- Raw material heat exchanger. DETAILED DESCRIPTION

[0069] In order to enable those skilled in the art to better understand the scheme of the utility model, the utility model is further described in detail below. The specific implementation methods listed below are only for describing the principles and features of the utility model. The examples are only used to explain the utility model and do not limit the scope of the utility model. Based on the embodiments of the utility model, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0070] The first aspect of the utility model provides a cold hydrogenation reaction device, which includes a vaporization unit, a filtering unit, and a slurry separation unit; the filtering unit includes a liquid phase filter, the liquid phase inlet of the liquid phase filter is connected to the residue discharge outlet of the vaporization unit, and the filter residue outlet of the liquid phase filter is connected to the filter residue inlet of the slurry separation unit.

[0071] The vaporization unit is used to contain hydrogen and silicon tetrachloride, wherein the hydrogen is in gaseous state and the silicon tetrachloride is in liquid state. The silicon tetrachloride is converted into gas in the vaporization unit and used for subsequent reactions together with the hydrogen. The utility model does not limit the specific selection of the vaporization unit. In one embodiment, the vaporization unit is a silicon tetrachloride vaporizer.

[0072] The silicon tetrachloride in the vaporization unit often contains a small amount of silicon powder, which cannot leave the vaporization unit with the vaporized silicon tetrachloride and will be deposited in the vaporization unit. Therefore, the vaporization unit needs to be drained regularly, that is, part of the liquid silicon tetrachloride in the vaporization unit carries the silicon powder and leaves the vaporization unit through the drain outlet of the vaporization unit and enters the filter unit through the liquid inlet of the liquid filter. The present utility model does not limit the working pressure of the vaporization unit. In one embodiment, the working pressure is 2.8MPa.

[0073] The filtration unit is used to remove impurities such as silicon powder contained in the silicon tetrachloride from the vaporization unit. The filtration unit includes a liquid phase filter, which allows the fluid containing impurities to pass through a filter screen with a size of 0.1-0.5 μm, thereby separating the silicon tetrachloride from the impurities.

[0074] The slurry separation unit is used to receive the filter residue discharged by the filter unit. The filter residue leaves the filter unit through the filter residue outlet of the liquid phase filter and enters the slurry separation unit through the filter residue inlet of the slurry separation unit. The slurry separation unit separates the filter residue and recycles the separated silicon tetrachloride. The utility model does not limit the specific recovery method of the slurry separation unit. In one embodiment, after the filter residue is subjected to solid-liquid separation treatment, the separated liquid phase is subjected to distillation treatment to obtain silicon tetrachloride. The utility model does not limit the working pressure of the slurry separation unit. In one embodiment, the working pressure is 0.1MPa.

[0075] The utility model does not limit the specific equipment selection of the slurry separation unit, which can be selected according to actual needs. In one embodiment, the slurry separation unit includes a slurry buffer tank and a slurry separation tank that are interconnected. The filter residue inlet of the slurry buffer tank is the filter residue inlet of the slurry separation unit.

[0076] Since the residual volume of the vaporization unit is large, the separation treatment of the slurry separation unit consumes a lot of energy. The inventors found that since the liquid phase filter has a high filtering accuracy, impurities such as silicon powder contained in silicon tetrachloride can be effectively removed by the liquid phase filter, so that the silicon tetrachloride discharged from the vaporization unit can be directly recovered without entering the slurry separation unit, thereby effectively reducing the load of the slurry separation unit and reducing energy consumption, thereby helping to reduce the energy consumption of the cold hydrogenation reaction device.

[0077] The cold hydrogenation reaction device provided by the utility model has the characteristics of small working load of slag slurry separation equipment and low energy consumption.

[0078] It is understandable that the cold hydrogenation reaction device provided by the utility model also includes a cold hydrogenation reaction unit, and the raw material inlet of the cold hydrogenation reaction unit is connected to the raw material outlet of the vaporization unit. The vaporization unit uses hydrogen and silicon tetrachloride to react with silicon powder to obtain silicon tetrachloride. In one embodiment, the cold hydrogenation reaction unit includes a cold hydrogenation reactor. Silicon tetrachloride is converted into gas in the vaporization unit and enters the cold hydrogenation reactor with hydrogen to react.

[0079] Furthermore, the cold hydrogenation reaction device provided by the utility model also includes a quenching unit, the logistics inlet of the quenching unit is connected to the logistics outlet of the cold hydrogenation reaction unit, and the high-boiling product outlet of the quenching unit is connected to the slurry separation unit. The unit uses the product obtained by the cold hydrogenation reaction, partially condenses the other part of the gaseous product, and then washes it to obtain a pure product and high boiling products. The high boiling products enter the slurry treatment unit for treatment. The utility model does not limit the equipment selection of the quenching unit. In one embodiment, the quenching unit includes a quenching tower and an auxiliary condensing device.

[0080] Furthermore, the cold hydrogenation reaction device provided by the utility model also includes a raw material heating unit, and the raw material outlet of the vaporization unit is connected to the raw material inlet of the cold hydrogenation reaction unit through the raw material heating unit.

[0081] The function of the raw material heating unit is to heat the raw material from the vaporization unit to a suitable temperature so that it can enter the cold hydrogenation reaction device for reaction.

[0082] The present novel method does not limit the specific equipment selection of the raw material heating unit. In one embodiment, the raw material heating unit is a raw material heat exchanger, which can heat the raw material temperature to 570°C and 2.75MPa.

[0083] In one embodiment, the cold hydrogenation reaction device provided by the utility model further includes a silicon tetrachloride storage unit, and the filtrate outlet of the liquid phase filter is connected to the liquid phase inlet of the silicon tetrachloride storage unit.

[0084] The silicon tetrachloride storage unit is used to store the pure silicon tetrachloride obtained by removing impurities for use in subsequent processes. The present invention does not limit the specific selection of the silicon tetrachloride storage unit, and it only needs to meet the demand for storing silicon tetrachloride. In one embodiment, the silicon tetrachloride storage unit is a silicon tetrachloride storage tank, and the liquid phase inlet of the silicon tetrachloride storage tank is the liquid phase inlet of the silicon tetrachloride storage unit. The present invention does not limit the working pressure of the silicon tetrachloride storage unit. In one embodiment, the working pressure is 0.38MPa.

[0085] In one embodiment, the cold hydrogenation reaction device provided by the utility model further includes a hydrogen supply unit and a preheating unit, and the liquid phase outlet of the silicon tetrachloride storage unit and the hydrogen outlet of the hydrogen supply unit are connected to the logistics inlet of the vaporization unit through the preheating unit.

[0086] The hydrogen supply unit is used to provide hydrogen required for the cold hydrogenation reaction, and the preheating unit is used to heat the hydrogen and silicon tetrachloride. The heated hydrogen and silicon tetrachloride enter the silicon tetrachloride vaporization unit for standby use.

[0087] The utility model does not limit the specific equipment selection of the hydrogen supply unit and the preheating unit. In one embodiment, the hydrogen supply unit is a raw hydrogen interface, and the preheating unit includes a static mixer and a preheater connected in sequence. The static mixer can mix hydrogen with silicon tetrachloride, and the preheater can heat the mixture to 115°C and 2.85MPa.

[0088] In this embodiment, the filtered silicon tetrachloride leaves the filtration unit through the filtrate outlet of the liquid phase filter and enters the silicon tetrachloride storage unit through the liquid phase inlet of the silicon tetrachloride storage unit for use in subsequent processes, so that the silicon tetrachloride in the exhaust of the vaporization unit does not pass through the slurry separation unit and is reused in the cold hydrogenation process.

[0089] In one embodiment, the cold hydrogenation reaction device provided by the utility model further includes a heat exchange unit, and the liquid phase outlet of the liquid phase filter is connected to the liquid phase inlet of the silicon tetrachloride storage unit through the heat exchange unit.

[0090] The heat exchange unit is used to perform heat exchange treatment on the silicon tetrachloride obtained by filtering the liquid phase filter. Specifically, in one embodiment, a temperature reduction treatment is performed. The temperature reduction treatment can eliminate the temperature difference between the silicon tetrachloride after filtering and the silicon tetrachloride in the silicon tetrachloride storage unit, so that the cold hydrogenation reaction device provided by the utility model has higher safety.

[0091] The utility model does not limit the specific equipment selection of the heat exchange unit. In one embodiment, the heat exchange unit is a shell and tube heat exchanger. The utility model also does not limit the heat exchange medium used by the heat exchange unit. In one embodiment, the heat exchange medium is circulating water with a temperature of 25°C. The temperature of silicon tetrachloride after filtration is 120°C, and after heat exchange treatment by the heat exchange unit, the temperature is 50°C.

[0092] In one embodiment, the cold hydrogenation reaction device provided by the utility model also includes a distillation unit and a hydrolysis unit, the liquid phase inlet of the distillation unit is connected to the liquid phase outlet of the slurry separation unit, and the logistics inlet of the hydrolysis unit is connected to the solid phase outlet of the slurry separation unit.

[0093] The distillation unit is used to process the liquid phase material produced by the slurry separation unit. The liquid phase mixture includes silicon tetrachloride, and the distillation unit can obtain silicon tetrachloride from the above liquid phase mixture through distillation treatment for use in subsequent processes. The utility model does not specifically limit the equipment selection of the distillation unit. In one embodiment, the distillation unit includes a distillation tower, and the liquid phase inlet of the distillation tower is the liquid phase inlet of the distillation unit.

[0094] In one embodiment, the product inlet of the distillation unit is connected to the product outlet of the quenching unit, and the stream of trichlorosilane and silicon tetrachloride mainly outputted from the quenching unit enters the distillation unit for separation.

[0095] The hydrolysis unit is used to process the solid phase material produced by the slurry separation unit. The solid phase material contains silicon powder. The hydrolysis unit uses a water-containing substance to mix with the silicon powder and transports the obtained material for external processing. The utility model does not specifically limit the equipment selection of the hydrolysis unit. In one embodiment, the hydrolysis unit includes a hydrolysis tank, and the logistics inlet of the hydrolysis tank is the logistics inlet of the hydrolysis unit.

[0096] The arrangement of the distillation unit and the hydrolysis unit enables further processing of the logistics discharged into the slurry separation unit, which helps to improve the production efficiency of the cold hydrogenation reaction device provided by the utility model.

[0097] Furthermore, in one embodiment, in the cold hydrogenation reaction device provided by the present invention, the silicon tetrachloride outlet of the distillation unit is connected to the liquid phase inlet of the silicon tetrachloride storage unit.

[0098] The above connection relationship enables the silicon tetrachloride separated by the distillation unit to enter the silicon tetrachloride storage unit for cold hydrogenation reaction, further improving the production efficiency of the cold hydrogenation reaction device provided by the utility model.

[0099] In one embodiment, the liquid phase filter includes a filter chamber having a filter element therein, and a filtrate chamber connected to the filter chamber for receiving filtrate, and the filtration unit also includes a first pressure gauge and a second pressure gauge, the first pressure gauge is connected to the filter chamber, and the second pressure gauge is connected to the filtrate chamber.

[0100] The liquid phase filter includes a filter chamber and a filtrate chamber, wherein the filter chamber is used to accommodate unfiltered silicon tetrachloride in the liquid phase filter. The filter chamber has a filter element, and the filter element is used to filter silicon tetrachloride containing silicon powder. The filtrate chamber is used to accommodate pure silicon tetrachloride obtained after filtration. The first pressure gauge is connected to the filter chamber to detect the filter chamber pressure; the second pressure gauge is connected to the filtrate chamber to detect the filtrate chamber pressure. Since the liquid phase filter is driven by liquid pressure, silicon tetrachloride passes through the filter element under the action of pressure and enters the filtrate chamber from the filter chamber, so the filter chamber pressure is higher than the filtrate chamber pressure. When the filter screen is blocked by more impurities, the pressure difference between the filter chamber and the filtrate chamber increases, which is manifested as an increase in the pressure difference between the first pressure gauge and the second pressure gauge. When the pressure difference is greater than the preset pressure difference value, the filtering can be stopped and the filter element can be cleaned. The utility model does not specifically limit the preset pressure difference value, which can be determined according to actual operating conditions. In one embodiment, the preset pressure difference value is 20KPa.

[0101] The cold hydrogenation reaction device provided by the utility model uses a first pressure gauge and a second pressure gauge to respectively detect the pressure of the filter chamber and the filtrate chamber, and determines the cleaning time by the pressure difference, so the energy saving feature is more prominent.

[0102] In one embodiment, the cold hydrogenation reaction device provided by the utility model includes N filter units, N≥1; when N>1, the N filter units are connected in parallel.

[0103] When N>1, the cold hydrogenation reaction device provided by the utility model includes N filter units, for example, a first filter unit, a second filter unit ... an Nth filter unit, each filter unit includes its own liquid phase filter. Parallel connection means that the liquid phase inlets of the liquid phase filters in the N filter units are interconnected, and the liquid phase outlets of the liquid phase filters in the N filter units are interconnected.

[0104] It is understandable that when N filter units are connected in parallel, the other units in the cold hydrogenation reaction device provided by the utility model that are connected to the N filter units may be 1 or N, preferably 1. For example, in one embodiment, N=2, the cold hydrogenation reaction device provided by the utility model includes a first filter unit and a second filter unit, and the slurry separation units that are connected to the filter units may be 1 or 2. When there is one slurry separation unit, the slurry separation unit is connected to the first filter unit and the second filter unit respectively; when there are two slurry separation units, the first slurry separation unit is connected to the first filter unit, and the second slurry separation unit is connected to the second filter unit.

[0105] For example, Figure 1 The structural diagram of the cold hydrogenation reaction device provided by the utility model when N=2. Figure 1 As shown, the device includes A-first filtering unit, B-second filtering unit, C-vaporization unit, D-slurry separation unit, E-silicon tetrachloride storage unit, F-hydrogen supply unit, G-preheating unit, H-heat exchange unit, I-distillation unit, J-hydrolysis unit, K-cold hydrogenation reaction unit, L-quenching unit, and M-raw material heating unit.

[0106] Among them, the E-silicon tetrachloride storage unit and the F-hydrogen supply unit are connected to the C-vaporization unit through the G-preheating unit, the residue outlet of the C-vaporization unit is connected to the A-first filter unit and the B-second filter unit respectively, the filter residue outlets of the A-first filter unit and the B-second filter unit are connected to the filter residue inlet of the D-slurry separation unit respectively, the liquid phase outlet of the D-slurry separation unit is connected to the liquid phase inlet of the I-distillation unit, and the solid phase outlet of the D-slurry separation unit is connected to the logistics inlet of the J-hydrolysis unit. The liquid phase outlets of the A-first filter unit and the B-second filter unit are connected to the liquid phase inlet of the E-silicon tetrachloride storage unit through the H-heat exchange unit. The raw material outlet of the C-vaporization unit is connected to the M-raw material heating unit, the K-cold hydrogenation reaction unit and the L-quenching unit in sequence, the high boiling point outlet of the L-quenching unit is connected to the D-slurry separation unit, and the product outlet of the L-quenching unit is connected to the product inlet of the I-distillation unit.

[0107] Specifically, the silicon tetrachloride from the E-silicon tetrachloride storage unit and the hydrogen from the F-hydrogen supply unit are preheated by the G-preheating unit and then enter the C-vaporization unit. The silicon tetrachloride containing silicon powder discharged from the C-vaporization unit is filtered out by the A-first filtering unit and the B-second filtering unit to remove the silicon powder. The filtered silicon tetrachloride is cooled in the heat exchange unit and then enters the silicon tetrachloride storage unit. The raw materials of the C-vaporization unit are heated by the M-raw material heating unit and then enter the K-cold hydrogenation reaction unit for cold hydrogenation reaction. The obtained products enter the L-quenching unit for elution. The high boiling products obtained by the L-quenching unit enter the D-slurry separation unit for treatment. The products obtained by the L-quenching unit enter the I-distillation unit for distillation treatment.

[0108] In one embodiment, N=2, and the working states of the first filter unit and the second filter unit are opposite; wherein the liquid phase outlet of the liquid phase filter of the first filter unit is also connected to the filter cavity of the second filter unit, and the liquid phase outlet of the liquid phase filter of the second filter unit is also connected to the filter cavity of the first filter unit. The first filter unit also includes a first buffer tank, and the liquid phase outlet of the liquid phase filter of the first filter unit is connected to the filter cavity of the second filter unit through the first buffer tank; the second filter unit includes a second buffer tank, and the liquid phase outlet of the liquid phase filter of the second filter unit is connected to the filter cavity of the first filter unit through the second buffer tank.

[0109] The first and second buffer tanks are used to temporarily store the filtered silicon tetrachloride, which can make the cold hydrogenation reaction device provided by the utility model run more stably. The filtered silicon tetrachloride leaves the liquid phase filter through the liquid phase outlet of the liquid phase filter, and enters the silicon tetrachloride storage unit through the liquid phase inlet of the silicon tetrachloride storage unit for storage after being temporarily stored in the first and second buffer tanks.

[0110] The residual silicon tetrachloride discharged from the vaporization unit enters the filter unit through the liquid phase inlet of the filter unit, and the silicon tetrachloride obtained after filtration leaves the filter unit through the liquid phase outlet of the filter unit. During the above process, the working state of the filter unit is "filtration"; when there are too many impurities adhering to the filter element of the liquid phase filter in the filter unit, the filter unit needs to be cleaned, and the filter unit is on standby after cleaning. During the above process, the working state of the filter unit is "cleaning". The working states of the first filter unit and the second filter unit are opposite, which means that when the working state of the first filter unit is filtering, the working state of the second filter unit is cleaning; when the working state of the second filter unit is filtering, the working state of the first filter unit is cleaning.

[0111] The utility model does not limit the specific implementation of the above working logic, and it can be implemented using common technical solutions in the field. In one embodiment, the above working logic can be implemented by valve settings. In one embodiment, the liquid phase inlet of the liquid phase filter of the first filter unit is provided with a first control valve, and the liquid phase inlet of the liquid phase filter of the second filter unit is provided with a second control valve, and the working states of the first control valve and the second control valve are opposite, that is, when the first control valve is in an open state, the second control valve is in a closed state; when the second control valve is in an open state, the first control valve is in a closed state.

[0112] Specifically, when the first control valve is in an open state, the second control valve is in a closed state, the working state of the first filter unit is filtering, and the working state of the second filter unit is cleaning. If the second filter unit needs to be washed, the filtered silicon tetrachloride can enter the filter cavity of the liquid phase filter of the second filter unit through the liquid phase outlet of the liquid phase filter of the first filter unit, and the filter element arranged in the filter cavity is washed, and the mixture including silicon tetrachloride and impurities obtained by washing is discharged through the filter residue outlet of the liquid phase filter of the second filter unit.

[0113] The utility model does not limit the communication mode between the liquid phase outlet of the liquid phase filter of the first filter unit and the filter cavity of the second filter unit. The two can be directly connected or indirectly connected, so long as the purpose of rinsing the filter element with the silicon tetrachloride after filtration is achieved. For example, in one embodiment, the liquid phase outlet of the liquid phase filter of the first filter unit can be connected to the filter cavity through the filtrate cavity of the second filter unit. In this embodiment, the silicon tetrachloride after filtration first passes through the filtrate cavity and then passes through the filter cavity to rinse the filter element.

[0114] It is understandable that the "cleaning" working state includes cleaning and standby. When the second filter unit completes cleaning and enters standby, the working state of the first filter unit is still filtering, and there is no need to wash the second filter unit. At this time, the filtered silicon tetrachloride can leave the first filter unit through the liquid phase outlet of the liquid phase filter of the first filter unit and enter the silicon tetrachloride storage unit through the liquid phase inlet of the silicon tetrachloride storage unit.

[0115] Correspondingly, if the first control valve is in a closed state and the second control valve is in an open state, the working states of the first and second filter units are opposite to those described above, which will not be described in detail here.

[0116] It can be understood that the above content is only one embodiment of realizing a specific working state. In one embodiment, a third control valve is further provided between the liquid phase outlet of the liquid phase filter of the first filter unit and the filter cavity of the second filter unit, and a fourth control valve is further provided between the liquid phase outlet of the liquid phase filter of the second filter unit and the filter cavity of the first filter unit. When the silicon tetrachloride obtained by filtering the first filter unit is used to clean the second filter unit, the first and third control valves are opened, and the second and fourth control valves are closed; when the silicon tetrachloride obtained by filtering the second filter unit is used to clean the first filter unit, the second and fourth control valves are opened, and the first and third control valves are closed; when the first filter unit is on standby, the second control valve is opened, and the first, third, and fourth control valves are closed, and the filtered silicon tetrachloride enters the silicon tetrachloride storage unit; conversely, when the second filter unit is on standby, the first control valve is opened, and the second, third, and fourth control valves are closed.

[0117] Furthermore, in one embodiment, a fifth control valve is provided at the liquid phase inlet of the silicon tetrachloride storage unit. When the first filter unit or the second filter unit is in a "cleaning" state and is being cleaned (not on standby), the fifth control valve is closed to prevent the cleaning liquid from directly entering the silicon tetrachloride storage unit.

[0118] The above connection relationship allows the two groups of filter units to serve as backup for each other, and the filtered silicon tetrachloride produced by one group of filter units can be used to clean the other group of filter units, so that the cold hydrogenation reaction device provided by the utility model has higher production efficiency.

[0119] For example, Figure 2 This is a device connection diagram of another embodiment of the cold hydrogenation reaction device provided by the utility model. Figure 2 As shown, the device includes A101-first liquid phase filter filter cavity, A102-first liquid phase filter filtrate cavity, A103-first liquid phase filter first pressure gauge, A104-first liquid phase filter second pressure gauge, A2-first buffer tank, A3-first control valve, A4-third control valve, B101-second liquid phase filter filter cavity, B102-second liquid phase filter filtrate cavity, B103-second liquid phase filter first pressure gauge, B104-second liquid phase filter The second pressure gauge of the filter, B2-the second buffer tank, B3-the second control valve, B4-the fourth control valve, C1-silicon tetrachloride vaporizer, D1-slurry buffer tank, D2-slurry separator, E1-silicon tetrachloride storage tank, E2-the fifth control valve, F1-raw material hydrogen interface, G1-static mixer, G2-preheater, H1-heat exchanger, I1-distillation tower, J1-hydrolysis tank, K1-cold hydrogenation reactor, L1-quenching tower and condensation equipment, M1-raw material heat exchanger.

[0120] Among them, A101-first liquid phase filter filter cavity, A102-first liquid phase filter filtrate cavity, A103-first liquid phase filter first pressure gauge, A104-first liquid phase filter second pressure gauge, A2-first buffer tank, A3-first control valve, A4-third control valve belong to A-first filter unit, B101-second liquid phase filter cavity, B102-second liquid phase filter filtrate cavity, B103-second liquid phase filter first pressure gauge, B104-second liquid phase filter second pressure gauge, B2-second buffer tank, B3-second control valve, B4-fourth control valve belong to B-second filter unit, C1-silicon tetrachloride The vaporizer belongs to the C-vaporization unit, D1-slurry buffer tank, D2-slurry separator belongs to the D-slurry separation unit, E1-silicon tetrachloride storage tank, E2-fifth control valve belongs to the E-silicon tetrachloride storage unit, F1-raw material hydrogen interface belongs to the F-hydrogen supply unit, G1-static mixer, G2-preheater belongs to the G-preheating unit, H1-heat exchanger belongs to the H-heat exchange unit, I1-distillation tower belongs to the I-distillation unit, J1-hydrolysis tank belongs to the J-hydrolysis unit, K1-cold hydrogenation reactor belongs to the K-cold hydrogenation reaction unit, L1-quenching tower and condensing equipment belong to the L-quenching unit, M1-raw material heat exchanger belongs to the M-raw material heating unit.

[0121] Further, A3-first control valve, A101-first liquid phase filter filter chamber, A102-first liquid phase filter filtrate chamber, and A2-first buffer tank are connected in sequence; B3-second control valve, B101-second liquid phase filter filter chamber, B102-second liquid phase filter filtrate chamber, and B2-second buffer tank are connected in sequence; A2-first buffer tank is connected to B102-second liquid phase filter filtrate chamber through A4-third control valve, and B2-second buffer tank is connected to A102-first liquid phase filter filtrate chamber through B4-fourth control valve.

[0122] A2-the first buffer tank and B2-the second buffer tank are connected to E1-silicon tetrachloride storage tank through H1-heat exchanger and E2-the fifth control valve. E1-silicon tetrachloride storage tank is connected to F1-raw material hydrogen interface and in turn connected to C1-silicon tetrachloride vaporizer through G1-static mixer and G2-preheater. C1-silicon tetrachloride vaporizer is respectively connected to A3-the first control valve and B3-the second control valve.

[0123] A101-the first liquid phase filter chamber and B101-the second liquid phase filter chamber are connected to D1-the slurry buffer tank and D2-the slurry separator in sequence, D2-the slurry separator is connected to I1-the distillation tower and J1-the hydrolysis tank respectively, and the silicon tetrachloride outlet of I1-the distillation tower is connected to the liquid phase inlet of C1-the silicon tetrachloride vaporizer.

[0124] The raw material outlet of C1-silicon tetrachloride vaporizer is connected to L1-quenching tower and condensing equipment through M1-raw material heat exchanger and K1-cold hydrogenation reactor, the product outlet of L1-quenching tower and condensing equipment is connected to I1-distillation tower, and the high boiling point outlet of L1-quenching tower and condensing equipment is connected to D1-slurry buffer tank.

[0125] The following selects typical operating conditions for discussion:

[0126] When the first liquid phase filter is working and the filtered silicon tetrachloride is used to clean the second liquid phase filter: A3-the first control valve and A4-the third control valve are opened, and the other control valves are closed.

[0127] C1-silicon tetrachloride vaporizer discharges silicon tetrachloride containing silicon powder, which is filtered through the first liquid phase filter. The filtered silicon tetrachloride is driven by the pressure difference and passes through the B102-second liquid phase filter filtrate chamber and the B101-second liquid phase filter filtration chamber in sequence through the A4-third control valve to reversely flush the impurities adhered to the filter element, and the filter residue containing silicon tetrachloride is obtained and passes through the D1-slurry buffer tank and the D2-slurry separator in sequence. The separated solid enters the J1-hydrolysis tank, and the liquid enters the I1-distillation tower for distillation treatment. The silicon tetrachloride obtained by distillation enters the E1-silicon tetrachloride storage tank to complete the recovery of silicon tetrachloride in the discharge.

[0128] When the first liquid phase filter is working and the second liquid phase filter is on standby: A3-the first control valve, A4-the third control valve, E2-the fifth control valve are opened, and the remaining control valves are closed.

[0129] C1-silicon tetrachloride vaporizer discharges silicon tetrachloride containing silicon powder, which is filtered through the first liquid phase filter. The filtered silicon tetrachloride passes through H1-heat exchanger and E2-fifth control valve in turn and enters E1-silicon tetrachloride storage tank to complete the recovery of silicon tetrachloride in the discharge.

[0130] The hydrogen vaporized from the C1-silicon tetrachloride vaporizer and the silicon tetrachloride mixer are heated up through the M1-raw material heat exchanger and then enter the K1-cold hydrogenation reactor for cold hydrogenation reaction. The product enters the L1-quenching tower and condensation equipment for washing. The washed product enters the I1-distillation tower for separation. The separated silicon tetrachloride enters the E1-silicon tetrachloride storage tank; the high boiling products obtained by washing enter the D2-slurry separator for treatment.

[0131] The third aspect of the present invention provides a polysilicon production system, which includes any one of the above cold hydrogenation reaction devices. Since the cold hydrogenation reaction device provided by the present invention has the advantage of less energy consumption, the polysilicon production system provided by the present invention also has the advantage of less energy consumption.

[0132] The present invention does not limit the types of other equipment included in the polysilicon production system, and can be selected according to production requirements. In one embodiment, the polysilicon production system provided by the present invention also includes a reduction furnace.

[0133] The high boiling point treatment device provided by the utility model is further described below through examples.

[0134] Example

[0135] This embodiment uses Figure 2 The cold hydrogenation equipment shown is used for production.

[0136] like Figure 2 As shown, the device includes A101-first liquid phase filter filtration chamber, A102-first liquid phase filter filtrate chamber, A103-first liquid phase filter first pressure gauge, A104-first liquid phase filter second pressure gauge, A2-first buffer tank, A3-first control valve, A4-third control valve, B101-second liquid phase filter filtration chamber, B102-second liquid phase filter filtrate chamber, B103-second liquid phase filter first pressure gauge, B104- The second pressure gauge of the second liquid phase filter, B2-the second buffer tank, B3-the second control valve, B4-the fourth control valve, C1-silicon tetrachloride vaporizer, D1-slurry buffer tank, D2-slurry separator, E1-silicon tetrachloride storage tank, E2-the fifth control valve, F1-raw material hydrogen interface, G1-static mixer, G2-preheater, H1-heat exchanger, I1-distillation tower, J1-hydrolysis tank, K1-cold hydrogenation reactor, L1-quenching tower and condensation equipment.

[0137] Among them, A101-first liquid phase filter filter cavity, A102-first liquid phase filter filtrate cavity, A103-first liquid phase filter first pressure gauge, A104-first liquid phase filter second pressure gauge, A2-first buffer tank, A3-first control valve, A4-third control valve belong to A-first filter unit, B101-second liquid phase filter cavity, B102-second liquid phase filter filtrate cavity, B103-second liquid phase filter first pressure gauge, B104-second liquid phase filter second pressure gauge, B2-second buffer tank, B3-second control valve, B4-fourth control valve belong to B-second filter Unit, C1-silicon tetrachloride vaporizer belongs to C-vaporization unit, D1-slurry buffer tank, D2-slurry separator belongs to D-slurry separation unit, E1-silicon tetrachloride storage tank, E2-fifth control valve belongs to E-silicon tetrachloride storage unit, F1-raw hydrogen interface belongs to F-hydrogen supply unit, G1-static mixer, G2-preheater belongs to G-preheating unit, H1-heat exchanger belongs to H-heat exchange unit, I1-distillation tower belongs to I-distillation unit, J1-hydrolysis tank belongs to J-hydrolysis unit, K1-cold hydrogenation reactor belongs to K-cold hydrogenation reaction unit, L1-quenching tower and condensing equipment belong to L-quenching unit.

[0138] Further, A3-first control valve, A101-first liquid phase filter filter chamber, A102-first liquid phase filter filtrate chamber, and A2-first buffer tank are connected in sequence; B3-second control valve, B101-second liquid phase filter filter chamber, B102-second liquid phase filter filtrate chamber, and B2-second buffer tank are connected in sequence; A2-first buffer tank is connected to B102-second liquid phase filter filtrate chamber through A4-third control valve, and B2-second buffer tank is connected to A102-first liquid phase filter filtrate chamber through B4-fourth control valve.

[0139] A2-the first buffer tank and B2-the second buffer tank are connected to E1-silicon tetrachloride storage tank through H1-heat exchanger and E2-the fifth control valve. E1-silicon tetrachloride storage tank is connected to F1-raw material hydrogen interface and in turn connected to C1-silicon tetrachloride vaporizer through G1-static mixer and G2-preheater. C1-silicon tetrachloride vaporizer is respectively connected to A3-the first control valve and B3-the second control valve.

[0140] A101-the first liquid phase filter chamber and B101-the second liquid phase filter chamber are connected to D1-the slurry buffer tank and D2-the slurry separator in sequence, D2-the slurry separator is connected to I1-the distillation tower and J1-the hydrolysis tank respectively, and the silicon tetrachloride outlet of I1-the distillation tower is connected to the liquid phase inlet of C1-the silicon tetrachloride vaporizer.

[0141] The raw material outlet of C1-silicon tetrachloride vaporizer is connected to L1-quenching tower and condensing equipment through M1-raw material heat exchanger and K1-cold hydrogenation reactor, the product outlet of L1-quenching tower and condensing equipment is connected to I1-distillation tower, and the high boiling point outlet of L1-quenching tower and condensing equipment is connected to D1-slurry buffer tank.

[0142] The specific operating conditions are as follows:

[0143] When the first liquid phase filter is working and the filtered silicon tetrachloride is used to clean the second liquid phase filter: A3-the first control valve and A4-the third control valve are opened, and the other control valves are closed.

[0144] C1-silicon tetrachloride vaporizer discharges silicon tetrachloride containing silicon powder, which is filtered through the first liquid phase filter. The filtered silicon tetrachloride is driven by the pressure difference and passes through the B102-second liquid phase filter filtrate chamber and the B101-second liquid phase filter filtration chamber in sequence through the A4-third control valve to reversely flush the impurities adhered to the filter element, and the filter residue containing silicon tetrachloride is obtained and passes through the D1-slurry buffer tank and the D2-slurry separator in sequence. The separated solid enters the J1-hydrolysis tank, and the liquid enters the I1-distillation tower for distillation treatment. The silicon tetrachloride obtained by distillation enters the E1-silicon tetrachloride storage tank to complete the recovery of silicon tetrachloride in the discharge.

[0145] When the first liquid phase filter is working and the second liquid phase filter is on standby: A3-the first control valve, A4-the third control valve, E2-the fifth control valve are opened, and the remaining control valves are closed.

[0146] C1-silicon tetrachloride vaporizer discharges silicon tetrachloride containing silicon powder, which is filtered through the first liquid phase filter. The filtered silicon tetrachloride passes through H1-heat exchanger and E2-fifth control valve in turn and enters E1-silicon tetrachloride storage tank to complete the recovery of silicon tetrachloride in the discharge.

[0147] The hydrogen vaporized from the C1-silicon tetrachloride vaporizer and the silicon tetrachloride mixer are heated up through the M1-raw material heat exchanger and then enter the K1-cold hydrogenation reactor for cold hydrogenation reaction. The product enters the L1-quenching tower and condensation equipment for washing. The washed product enters the I1-distillation tower for separation. The separated silicon tetrachloride enters the E1-silicon tetrachloride storage tank; the high boiling products obtained by washing enter the D2-slurry separator for treatment.

[0148] Comparative Example

[0149] This comparative example uses Figure 3 The cold hydrogenation equipment shown is used for production.

[0150] like Figure 3As shown, the equipment includes C1-silicon tetrachloride vaporizer, D1-slurry buffer tank, D2-slurry separator, E1-silicon tetrachloride storage tank, F1-raw material hydrogen interface, G1-static mixer, G2-preheater, H1-heat exchanger, I1-rectifier, J1-hydrolysis tank, K1-cold hydrogenation reactor, L1-quenching tower and condensing equipment, M1-raw material heat exchanger. Among them, the exhaust residue of C1-silicon tetrachloride vaporizer is not filtered, but first enters L1-quenching tower and condensing equipment, and then enters D1-slurry buffer tank. The connection relationship of the remaining equipment is the same as that of the embodiment.

[0151] Test example

[0152] The cold hydrogenation process of polysilicon with an annual output of 50,000 tons was carried out using the embodiment and the comparative example. The energy consumption of the distillation equipment was statistically analyzed, and it was found that the embodiment could save 49,000 GJ of energy per year compared with the comparative example.

[0153] It can be seen from Table 1 that the cold hydrogenation reaction device provided by the utility model has the advantage of low energy consumption.

[0154] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0155] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the comparative examples of the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the utility model.

Claims

1. A cold hydrogenation reaction device, characterized in that: It includes a vaporization unit, a filtering unit, and a slurry separation unit; The filtering unit comprises a liquid phase filter, a liquid phase inlet of the liquid phase filter is communicated with a residue discharge outlet of the vaporization unit, and a filter residue outlet of the liquid phase filter is communicated with a filter residue inlet of the slurry separation unit.

2. The device according to claim 1, characterized in that It also includes a silicon tetrachloride storage unit, and the filtrate outlet of the liquid phase filter is connected to the liquid phase inlet of the silicon tetrachloride storage unit.

3. The device according to claim 2, characterized in that It also includes a hydrogen supply unit and a preheating unit. The liquid phase outlet of the silicon tetrachloride storage unit and the hydrogen outlet of the hydrogen supply unit are connected to the logistics inlet of the vaporization unit through the preheating unit.

4. The device according to claim 3, characterized in that It also includes a heat exchange unit, and the liquid phase outlet of the liquid phase filter is connected to the liquid phase inlet of the silicon tetrachloride storage unit through the heat exchange unit.

5. The device according to claim 4, characterized in that It also includes a distillation unit and a hydrolysis unit. The liquid phase inlet of the distillation unit is connected to the liquid phase outlet of the slurry separation unit, and the logistics inlet of the hydrolysis unit is connected to the solid phase outlet of the slurry separation unit.

6. The device according to claim 5, characterized in that The silicon tetrachloride outlet of the distillation unit is in communication with the liquid phase inlet of the silicon tetrachloride storage unit.

7. The device according to claim 6, characterized in that The liquid phase filter includes a filter cavity with a filter element inside, and a filtrate cavity connected to the filter cavity for receiving filtrate. The filtration unit also includes a first pressure gauge and a second pressure gauge, the first pressure gauge is connected to the filter cavity, and the second pressure gauge is connected to the filtrate cavity.

8. The device according to any one of claims 1 to 7, characterized in that It includes N filtering units, N≥1; When N>1, N filtering units are connected in parallel.

9. The device according to claim 8, characterized in that N=2, the working states of the first filter unit and the second filter unit are opposite; Wherein, the liquid phase outlet of the liquid phase filter of the first filter unit is also connected to the filter cavity of the second filter unit, and the liquid phase outlet of the liquid phase filter of the second filter unit is also connected to the filter cavity of the first filter unit; The first filter unit further includes a first buffer tank, and the liquid phase outlet of the liquid phase filter of the first filter unit is connected to the filter cavity of the second filter unit through the first buffer tank; The second filter unit includes a second buffer tank, and the liquid phase outlet of the liquid phase filter of the second filter unit is connected with the filter cavity of the first filter unit through the second buffer tank.

10. A polysilicon production system, characterized in that: A cold hydrogenation reaction device comprising the cold hydrogenation reaction device according to any one of claims 1 to 9.

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