Automatic powder discharging and dust removing device of tail gas recovery system

Abstract

The utility model provides an automatic powder discharge and dust removal device of a tail gas recovery system, which comprises a tail gas inlet used for receiving tail gas discharged by an upstream system, the tail gas inlet is connected with an opening in the side surface of the lower part of a filter, and an opening in the upper part of the filter is connected with a tail gas outlet and used for discharging the tail gas; the filter is used for filtering silicon powder in the tail gas, and the lower end of the filter is connected with the upper end of the silicon powder buffer tank; the silicon powder buffer tank is used for storing the silicon powder filtered in the filter, the lower end of the silicon powder buffer tank is connected with a silicon powder ton bag through a vacuumizing pipeline, and the silicon powder is finally placed in the silicon powder ton bag; and the vacuumizing pipeline is used for forming negative pressure in the silicon powder ton bag. According to the device, dust flying is avoided, meanwhile, manual line stopping and powder discharging can be achieved through automatic powder discharging, the cleanness of a powder discharging site is guaranteed, and meanwhile the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a powder discharge and dust removal device, in particular to an automatic powder discharge and dust removal device for a tail gas recovery system. Background Art

[0002] In the production of granular silicon, the tail gas of granular silicon contains a large amount of silicon powder, which can be recycled for casting silicon ingots of downstream clients, so the purity of silicon powder is required to be high. In the process of silicon powder recovery, the manual discharge of powder is not timely, which will increase the load of the filter and affect the dust removal effect. Because the manual discharge of powder is intermittent, the front-end dust removal device is required to be in standby mode during the discharge, which affects the production efficiency. At the same time, the fluttering of silicon powder dust during the discharge is easy to cause fire and explosion hazards. Utility Model Content

[0003] Purpose of the invention: The technical problem to be solved by the utility model is to provide an automatic powder discharge and dust removal device for an exhaust gas recovery system in view of the deficiencies in the prior art.

[0004] In order to solve the above-mentioned technical problems, the utility model discloses an automatic powder discharge and dust removal device of an exhaust gas recovery system, comprising: an exhaust gas inlet, for receiving the exhaust gas discharged from an upstream system, the exhaust gas inlet is connected to the lower side opening of the filter, the upper opening of the filter is connected to the exhaust gas outlet, for discharging the exhaust gas; the filter is used to filter the silicon powder in the exhaust gas, the lower end of the filter is connected to the upper end of the silicon powder buffer tank; the silicon powder buffer tank is used to store the silicon powder filtered in the filter, the lower end of the silicon powder buffer tank is connected to the silicon powder ton bag through a vacuum pipeline; the vacuum pipeline is used to form a negative pressure in the silicon powder ton bag.

[0005] Furthermore, the vacuum pipeline is a double-layer hollow structure, including: an inner pipe, whose upper end is connected to the lower end of the silicon powder buffer tank, and the lower end is inserted into the silicon powder bag; the inner pipe is outer-jacketed; the outer jacket and the inner pipe are hollow structures; the upper end of the outer jacket is closed and fixedly connected to the outer wall of the inner pipe, and the lower end opening is higher than the lower end opening of the inner pipe; a second nitrogen inlet and a vacuum port are provided on the outer wall of the outer jacket, which are respectively used to transport nitrogen into the hollow structure and draw vacuum to form negative pressure.

[0006] Furthermore, the filter is a hollow structure, in which a filter element is provided for filtering the exhaust gas; the filter element is inserted on a filter element plate, and the filter element plate is horizontally arranged in the filter.

[0007] Furthermore, a first nitrogen inlet is provided on the side wall of the filter for blowing off the silicon powder adsorbed on the filter element.

[0008] Furthermore, the filter is connected to the silicon powder buffer tank via a first short-circuit pipe and a first gate valve.

[0009] Furthermore, the silicon powder buffer tank is connected to the vacuum line via a second short-circuit pipe and a second gate valve.

[0010] Furthermore, a weighing module is provided under the silicon powder ton bag for measuring the weight of the silicon powder in the silicon powder ton bag.

[0011] Furthermore, the weighing module is electrically connected to the second gate valve for transmitting a control signal for opening and closing the second gate valve.

[0012] Furthermore, the exhaust gas inlet is tangent to the inner wall of the filter, and a flow guide device is provided at a corresponding position of the inner wall of the filter to reduce turbulence caused by the exhaust gas.

[0013] Furthermore, all parts of the device that come into contact with the silicon powder are provided with clean materials.

[0014] Beneficial effects:

[0015] 1. Before discharging silicon powder into ton bags, a vacuum pipeline is set up to effectively solve the problem of flying dust and ensure the safety factor of the production site.

[0016] 2. The ton bag weighing system is designed to control the switch of the gate valve 2 through the metering and weighing system to realize the automatic powder discharge function, replace the manual powder discharge, avoid stopping the line to back-blow the filter, and effectively improve the production efficiency.

[0017] 4. The entire automatic powder discharge device is sprayed or lined with clean materials to avoid contact with pollution sources and effectively improve the quality of silicon powder.

[0018] 5. The automatic powder discharge device adopts a pneumatic gate valve, which is light in weight, quick to open and close, and easy to operate. The opening and closing device realizes dust-free lubricated transmission, avoids the influence of dust and rust on the transmission, ensures that the gate valve is time-saving and labor-saving during operation, and is tightly closed.

[0019] 6. The tail gas after dust removal in the filter enters nitrogen inlet 1 and nitrogen inlet 2 for recycling, and the remaining part is reused in the front-end dust removal device to achieve the purpose of saving resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, and the above and / or other advantages of the present invention will become more clear.

[0021] Figure 1 It is a schematic diagram of the overall structure.

[0022] Figure 2This is a schematic diagram of the vacuum pipeline.

[0023] Figure 3 This is a schematic diagram of the interior of the filter and the exhaust gas flow direction.

[0024] Figure 4 It is a schematic diagram of filter element distribution and injection device distribution.

[0025] Figure 1 Among them, 1 is the exhaust gas outlet, 2 is the filter, 3 is the first short-circuit pipe, 4 is the first plug-in valve, 5 is the silicon powder buffer tank, 6 is the second short-circuit pipe, 7 is the second plug-in valve, 8 is the vacuum pipeline, 9 is the silicon powder ton bag, 10 is the weighing module; 11 is the exhaust gas inlet, 12 is the first nitrogen inlet; 13 is the filter element; 14 is the filter element plate; 15 is the guide device; 801 is the second nitrogen inlet, 802 is the vacuum port, 803 is the inner pipeline, and 804 is the outer jacket. DETAILED DESCRIPTION

[0026] The utility model proposes an automatic powder discharge and dust removal device for an exhaust gas recovery system, such as Figure 1 As shown, the specific technical solution is as follows:

[0027] The tail gas inlet 11 is used to receive the tail gas discharged from the upstream system, and is connected to the lower side opening of the filter 2. The upper opening of the filter 2 is connected to the tail gas outlet 1 for discharging the tail gas; the tail gas outlet 1 can be set at the top or upper side of the filter 2;

[0028] The filter 2 is used to filter the silicon powder in the exhaust gas, and the lower end of the filter 2 is connected to the upper end of the silicon powder buffer tank 5; the silicon powder buffer tank 5 is used to store the silicon powder filtered in the filter 2, and the lower end of the silicon powder buffer tank 5 is connected to the silicon powder big bag 9 through the vacuum pipeline 8, and the silicon powder is finally placed in the silicon powder big bag 9; the vacuum pipeline 8 is used to form negative pressure in the silicon powder big bag 9.

[0029] like Figure 2 As shown, the vacuum pipeline 8 is a double-layer hollow structure, including: an inner pipe 801, whose upper end is connected to the lower end of the silicon powder buffer tank 5, and the lower end is inserted into the silicon powder bulk bag 9, the inner pipe 801 is provided with an outer jacket 804, the outer jacket 804 and the inner pipe 801 are hollow structures, the upper end of the outer jacket 804 is closed and fixedly connected to the outer wall of the inner pipe 801, and the lower end opening is higher than the lower end opening of the inner pipe 801; a second nitrogen inlet 801 and a vacuum port 802 are provided on the outer wall of the outer jacket 804, which are respectively used to transport nitrogen into the hollow structure and extract vacuum to form negative pressure.

[0030] like Figure 3As shown, the filter 2 is a hollow structure, in which a filter element 13 is provided for filtering the exhaust gas; the filter element 13 is inserted on a filter element plate 14, and the filter element plate 14 is horizontally arranged in the filter 2.

[0031] The side wall of the filter 2 is also provided with a first nitrogen inlet 12 for blowing off the silicon powder adsorbed on the filter element 13 .

[0032] The filter 2 is connected to the silicon powder buffer tank 5 through a first short-circuit pipe 3 and a first gate valve 4 .

[0033] The silicon powder buffer tank 5 is connected to the vacuum line 8 via a second short-circuit pipe 6 and a second gate valve 7 .

[0034] A weighing module 10 is provided below the silicon powder big bag 9 for measuring the weight of the silicon powder in the silicon powder big bag 9 .

[0035] The weighing module 10 is electrically connected to the second gate valve 7 and is used to transmit a control signal for opening and closing the second gate valve 7 .

[0036] The exhaust gas inlet 11 is tangent to the inner wall of the filter 2 , and a flow guide device 15 is provided at a corresponding position of the inner wall of the filter 2 to reduce turbulence caused by the exhaust gas.

[0037] All parts of the device that come into contact with the silicon powder are provided with clean materials to ensure the cleanliness of the silicon powder;

[0038] The clean material described above can be sprayed polyurethane material or installed single crystal pipe fittings.

[0039] Example:

[0040] The device proposed by the utility model has the following working process: Figure 3 As shown, the exhaust gas containing silicon powder after the granular silicon dust removal enters the filter 2 through the exhaust gas inlet. The filter 2 is composed of a filter element 13, a backflush system (exhaust gas inlet 11 and exhaust gas outlet 1) and other systems. Among them, the filter 2 is a non-metallic filter, and the main material of the filter element 13 is a PP skeleton and PTFE filter material, and the filtration accuracy is less than 0.04μm. The filter element plate 14 is horizontally arranged inside the filter 2, and one or more filter element holes are opened on it. The filter element 13 is in the shape of a long strip and inserted in the filter element hole to filter silicon powder. In order to protect and extend the life of the filter element 13, the exhaust gas inlet of the filter adopts a tangent form. After the gas enters the tank body, the impact force on the filter element is avoided. The internal design of the guide device 15 reasonably arranges the gas flow direction, reduces the turbulence inside the filter, and makes the dust-containing airflow evenly distributed on the filter element. The exhaust gas passes through the filter element 13 and retains the silicon powder on the surface of the filter element 13, thereby protecting the filter element to the greatest extent. As Figure 4As shown, the silicon powder on the surface of the filter element 13 falls down through the back-blowing nitrogen, and is discharged into the silicon powder buffer tank through the short circuit 1 and the gate valve 1 of the lining clean material in turn, and the gate valve 1 above the silicon powder buffer tank is kept open. The tail gas after dust removal in the filter is discharged from the tail gas outlet. This part of the tail gas is mainly nitrogen, so the discharged nitrogen part enters the nitrogen inlet 1 and the nitrogen inlet 2 for recycling, and the remaining part is reused in the front-end dust removal device.

[0041] Silicon powder is stored in the buffer tank. When the weighing and metering system shows that it is higher than the lower limit and lower than the upper limit, the gate valve 2 opens automatically. The silicon powder in the buffer tank is discharged into the ton bag under pressure through the short circuit 2 lined with clean materials, the gate valve 2, and the vacuum pipeline. When the weight of the silicon powder in the ton bag is higher than the upper limit of the weighing and metering system or lower than the lower limit, the gate valve 2 closes automatically and stops discharging the powder. During this powder discharge process, the vacuum port on the vacuum pipeline vacuums the ton bag to prevent the silicon powder from escaping. At the same time, in order to prevent the ton bag from deforming due to negative pressure, nitrogen is introduced through the nitrogen inlet 2 on the vacuum pipeline to ensure that the pressure of the ton bag is slightly negative.

[0042] like Figure 2 As shown, the vacuum pipeline is a double-layer structure consisting of an inner layer pipeline and an outer layer jacket, and a nitrogen inlet 2 and a vacuum port are arranged on the outer layer jacket. The inner layer is a pipeline structure, and the pipeline structure is lined with a clean coating, and the inner layer pipeline is longer than the outer layer jacket. The mouth of the silicon powder ton bag is wrapped on the outer wall of the jacket. When discharging the powder, the outer layer jacket is vacuumed and nitrogen is introduced to keep the ton bag at a slight negative pressure to prevent the silicon powder from being sprayed out from the wrapped mouth due to the pressure inside the ton bag being higher than the outside.

[0043] During the entire silicon powder recovery process, in order to ensure the cleanliness of the silicon powder and prevent the introduction of other impurities such as metals, the filters, silicon powder buffer tanks, gate valve 1, gate valve 2, short circuit 1, short circuit 2, and vacuum pipelines that come into contact with the silicon powder must be sprayed or lined with clean materials, such as polyurethane materials, silicon nitride, single crystal materials and other clean materials.

[0044] The utility model provides an idea and method for an automatic dust removal and dust removal device of an exhaust gas recovery system. There are many methods and ways to implement the technical solution. The above is only a preferred implementation of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications should also be regarded as the protection scope of the utility model. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. An automatic dust removal and exhaust device for an exhaust gas recovery system, characterized in that: include: An exhaust gas inlet (11) is used to receive exhaust gas discharged from an upstream system, the exhaust gas inlet (11) is connected to the lower side opening of the filter (2), and the upper opening of the filter (2) is connected to the exhaust gas outlet (1) for discharging exhaust gas; the filter (2) is used to filter silicon powder in the exhaust gas, the lower end of the filter (2) is connected to the upper end of a silicon powder buffer tank (5); the silicon powder buffer tank (5) is used to store the silicon powder filtered from the filter (2), the lower end of the silicon powder buffer tank (5) is connected to a silicon powder ton bag (9) through a vacuum line (8), and the silicon powder ton bag (9) is used to place the silicon powder; the vacuum line (8) is used to form a negative pressure in the silicon powder ton bag (9).

2. The automatic dust removal and exhaust gas recovery system according to claim 1 is characterized in that: The vacuum pipeline (8) is a double-layer hollow structure, comprising: an inner pipe (803), the upper end of which is connected to the lower end of the silicon powder buffer tank (5), and the lower end is inserted into the silicon powder ton bag (9); the inner pipe (803) is provided with an outer jacket (804) on the outer jacket; the outer jacket (804) and the inner pipe (803) are hollow structures; the upper end of the outer jacket (804) is closed and fixedly connected to the outer wall of the inner pipe (803), and the lower end opening is higher than the lower end opening of the inner pipe (803); the outer wall of the outer jacket (804) is provided with a second nitrogen inlet (801) and a vacuum port (802), which are respectively used to transport nitrogen into the hollow structure and extract vacuum to form a negative pressure.

3. The automatic dust removal and exhaust gas removal device of the exhaust gas recovery system according to claim 1, characterized in that: The filter (2) is a hollow structure, in which a filter element (13) is provided for filtering the exhaust gas; the filter element (13) is inserted on a filter element flower plate (14), and the filter element flower plate (14) is horizontally arranged in the filter (2).

4. The automatic dust removal and exhaust gas removal device of the tail gas recovery system according to claim 3 is characterized in that: The side wall of the filter (2) is also provided with a first nitrogen inlet (12) for blowing off the silicon powder adsorbed on the filter element (13).

5. The automatic dust removal and exhaust gas recovery system according to claim 1 is characterized in that: The filter (2) is connected to the silicon powder buffer tank (5) via a first short-circuit pipe (3) and a first gate valve (4).

6. The automatic dust removal and exhaust gas recovery system according to claim 1, characterized in that: The silicon powder buffer tank (5) is connected to the vacuum pipeline (8) via a second short-circuit pipeline (6) and a second gate valve (7).

7. The automatic dust removal and exhaust gas removal device of the exhaust gas recovery system according to claim 6, characterized in that: A weighing module (10) is provided below the silicon powder ton bag (9) for measuring the weight of the silicon powder in the silicon powder ton bag (9).

8. The automatic dust removal and exhaust gas removal device of the tail gas recovery system according to claim 7, characterized in that: The weighing module (10) is electrically connected to the second gate valve (7) and is used to transmit a control signal for opening and closing the second gate valve (7).

9. The automatic dust removal and exhaust gas removal device of the tail gas recovery system according to claim 1, characterized in that: The exhaust gas inlet (11) is tangent to the inner wall of the filter (2), and a flow guide device (15) is provided at a corresponding position of the inner wall of the filter (2) to reduce turbulence caused by the exhaust gas.

10. The automatic dust removal and exhaust gas recovery system according to any one of claims 1 to 9, characterized in that: All parts of the device that come into contact with the silicon powder are provided with clean materials.

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