A heat exchanger hanging piece water recycling system for polysilicon production

Abstract

The utility model discloses a heat exchanger hanging piece water recycling system for polysilicon production relates to polysilicon wastewater treatment equipment technical field, including the water collecting main pipe and pneumatic pump, the water collecting main pipe is laid in the hanging piece outer drainage end of heat exchanger, and the water collecting main pipe and all hanging pieces of heat exchanger outside drainage point position one -to -one and are communicated through the pipeline, the air inlet of pneumatic pump is equipped with gas source interface, and gas source interface is used for accessing nitrogen gas pipeline or instrument gas source pipeline, and the fluid import of pneumatic pump and the water outlet of water collecting main pipe seal intercommunication, and the fluid export of pneumatic pump and the circulating water backwater pipe network in polysilicon production system seal intercommunication, through pneumatic pump, the hanging piece outer drainage of collection in water collecting main pipe is transported to circulating water backwater pipe network after pressurization, when monitoring the corrosion condition of circulating water heat exchanger in the prior art using the mode of hanging hanging piece, the water resource waste caused by the hanging piece water direct discharge to the rainwater ditch, and there is certain security risk problem.

Description

Technical Field

[0001] This utility model relates to the technical field of polysilicon wastewater treatment equipment, specifically to a system for recycling water from heat exchanger fins used in polysilicon production. Background Technology

[0002] Currently, some polysilicon manufacturers monitor the corrosion of circulating water heat exchangers using a suspended fin method. The specific operating procedure is as follows: a DN25 (or DN20) branch pipe is drawn from the return water line of the circulating water heat exchanger, with a flow rate of 0.5~1.3m³. 3 / h, connect the hanging bracket, so that the circulating water return flows through the stainless steel (or carbon steel) hanging bracket and is discharged externally. Our company's hanging bracket external drainage is directly discharged into the rainwater ditch.

[0003] However, this monitoring method has obvious problems. Due to the large number of monitoring points, the total drainage volume from these points is substantial, directly resulting in a serious waste of water resources. Furthermore, the practice of directly discharging water from these points into storm drains not only leads to low water resource utilization but also harbors several potential risks: On the one hand, the rainwater ditches retain water for a long time during non-rainy weather, which does not meet the environmental management requirements of "separation of clean water and sewage". On the other hand, the foundation of the equipment is soaked by these discharged waters for a long time, which is prone to local settlement and thus poses a risk of foundation collapse, which is extremely detrimental to maintaining safe production conditions.

[0004] In light of this situation, relevant staff are optimizing the system to resolve the aforementioned technical issues. Summary of the Invention

[0005] The purpose of this invention is to propose a heat exchanger fin water recycling system for polycrystalline silicon production, which solves the problem that the fin water generated when monitoring the corrosion of circulating water heat exchangers by suspending fins is directly discharged into the rainwater ditch, resulting in water waste and certain safety hazards.

[0006] This utility model is achieved through the following technical solution: A system for recycling water from heat exchanger fins used in polycrystalline silicon production includes a main water collection pipe and a pneumatic pump. The main water collection pipe is installed at the external drainage end of the heat exchanger fins, and the main water collection pipe corresponds one-to-one with the external drainage points of all the heat exchanger fins and is connected to them via pipelines. The pneumatic pump is equipped with an air source interface at its air inlet end, which is used to connect to a nitrogen pipeline or an instrument air source pipeline. The fluid inlet of the pneumatic pump is sealed and connected to the water outlet of the main water collection pipe, and the fluid outlet of the pneumatic pump is sealed and connected to the circulating water return network in the polysilicon production system. The pneumatic pump pressurizes the drainage from the outer surface of the hanging plates collected in the main water collection pipe and then transports it to the circulating water return network.

[0007] Furthermore, the diameter of the main water collection pipe is DN50~DN80.

[0008] Furthermore, the nitrogen pipeline is connected to a nitrogen storage tank or nitrogen pipeline network in the polysilicon production system that stores surplus industrial nitrogen; the instrument gas source pipeline is connected to an instrument gas source storage tank or instrument gas pipeline network in the polysilicon production system that stores surplus industrial instrument gas.

[0009] Furthermore, a flow sensor is installed on the pipe between the outlet of the main water collection pipe and the fluid inlet of the pneumatic pump.

[0010] Furthermore, the flow sensor is connected to the air source control valve of the pneumatic pump.

[0011] Furthermore, the pneumatic pump is a steam condensate pneumatic pump.

[0012] Furthermore, the laying path of the main water collection pipe covers several hanging plate drainage points, and the external drainage end of the hanging plate is connected to the main water collection pipe through an inclined pipe or a vertical pipe.

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects: I. In this utility model, by connecting the main water collection pipe to all external drainage points of the wafers one by one, centralized and comprehensive collection of external drainage from the wafers is achieved, avoiding water waste caused by traditional decentralized drainage. A pneumatic pump is used instead of a traditional electric pump, and it can be connected to a nitrogen pipeline or instrument air source, directly utilizing the existing industrial air source in the polysilicon production system without the need for additional power equipment, thus reducing equipment investment and power consumption. The pneumatic pump pressurizes the recycled water and sends it into the circulating water return network for centralized treatment, and allows the external drainage to re-enter the production cycle, significantly improving water resource utilization and reducing the fresh water consumption cost in polysilicon production. At the same time, the sealed and connected structural design reduces water leakage and pollution, improving the safety of the production environment.

[0014] Second, the reasonable design of the main water collection pipe diameter in this utility model (adapting to the total flow rate and transportation requirements of the external drainage of the hanging plate) can avoid the problems of excessive drainage resistance and water accumulation caused by too small a pipe diameter, and can also prevent material waste and excessive installation space occupation caused by too large a pipe diameter; the appropriate pipe diameter can ensure that the external drainage flows smoothly in the pipe, reduce the risk of pipe blockage, improve collection efficiency, and at the same time reduce energy loss in the fluid transportation process, ensuring the stable operation of the subsequent pneumatic pump.

[0015] Third, in this utility model, the nitrogen pipeline and the instrument gas source pipeline are respectively connected to the surplus industrial nitrogen storage tank and the surplus instrument gas source storage tank, which can make full use of the surplus gas source generated in the polysilicon production process, realize "turning waste into treasure", and avoid the energy waste caused by the direct emission of surplus gas source; there is no need to purchase or prepare additional driving gas source, which significantly reduces the operating cost of the system, while reducing the energy consumption and carbon emissions caused by the addition of gas source equipment, which is in line with the production concept of energy conservation and environmental protection.

[0016] Fourth, in this utility model, the flow sensor can monitor the collection flow of the external drainage of the bracket in real time, which makes it easy for operators to intuitively grasp the amount of water recovered by the system and provide data support for production management; the flow data can promptly detect drainage abnormalities (such as a sudden decrease in flow may indicate pipe blockage or bracket failure), which facilitates quick troubleshooting, avoids the decline in recovery efficiency caused by hidden faults, and ensures the stable operation of the recovery system.

[0017] V. In this utility model, the control connection between the flow sensor and the air source control valve enables the system to adaptively adjust. When the flow rate increases, the air supply is automatically increased to enhance the pneumatic pump's delivery capacity; when the flow rate decreases, the air supply is automatically reduced to lower energy consumption, avoiding energy waste caused by the pneumatic pump operating at "full load." Simultaneously, this linkage control ensures that the external drainage delivery pressure matches the flow rate, preventing sudden increases or decreases in pipeline pressure due to flow fluctuations, extending the service life of pipelines and equipment, and improving the stability and economy of system operation.

[0018] VI. In this utility model, the steam condensate pneumatic pump is specifically designed for treating steam condensate (the main component of the external drainage of the finned pump). Its internal structure and materials are adapted to the water quality characteristics of the condensate (such as temperature, purity, etc.), which can reduce pump wear caused by water corrosion or impurity deposition and extend the service life of the equipment. At the same time, this type of pneumatic pump has high conveying efficiency and stability, which can ensure that the external drainage of the finned pump is efficiently conveyed with low energy consumption, reducing the maintenance frequency and cost of the system.

[0019] VII. In this utility model, the main water collection pipe is laid along a path that covers several hanging plate drainage points, which can reduce the dispersed layout of the pipeline, simplify the system structure, and reduce the difficulty of installation and maintenance. The external drainage end of the hanging plate is connected to the main water collection pipe through an inclined pipe, and the external drainage is promoted to flow smoothly into the main water collection pipe by gravity, avoiding water stagnation, scale accumulation or bacterial growth caused by horizontal or reverse slope of the pipeline, ensuring the timeliness of drainage and pipeline cleanliness, and further improving the recycling efficiency of external drainage and water quality stability. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a heat exchanger finned water recycling system.

[0021] Figure 2This is a schematic diagram of another implementation of a heat exchanger finned water recycling system.

[0022] Figure 3 This is a schematic diagram showing the connection between the inclined pipe and the main water collection pipe.

[0023] Figure 4 This is a structural diagram of another implementation of a heat exchanger finned water recycling system.

[0024] The components include: 1. Main water collection pipe; 2. Pneumatic pump; 3. Heat exchanger; 4. Bracket; 5. Nitrogen pipeline; 6. Instrument air supply pipeline; 7. Circulating water return network; 8. Nitrogen storage tank; 9. Circulating water pipeline; 10. Instrument air supply storage tank; 11. Flow sensor; 12. Inclined pipe; 13. Nitrogen network; 14. Instrument air network; 1.1 Water outlet; 2.1 Air source interface; 2.2 Fluid inlet; 2.3 Fluid outlet; 2.4 Exhaust pipeline. Detailed Implementation The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0025] Example 1 A heat exchanger fin water recycling system for polysilicon production, reference Figure 1 It includes a water collection main pipe 1 and a pneumatic pump 2. The water collection main pipe 1 is laid at the external drainage end of the hanging plate 4 of the heat exchanger 3, and the water collection main pipe 1 corresponds one-to-one with the external drainage points of all the hanging plates 4 of the heat exchanger 3 and is connected through pipes to collect the external drainage generated by each hanging plate 4.

[0026] The medium inlet of the heat exchanger 3 is connected to the circulating water pipeline 9. The circulating water cools the material and recovers part of the condensate. After heat exchange, part of the circulating water enters the plate 4 (or plate holder) for monitoring the corrosion rate; the rest of the circulating water is sent to the circulating water return network 7.

[0027] The pneumatic pump 2 has an air source interface 2.1 at its air inlet, which is used to selectively connect to the nitrogen pipeline 5 or the instrument air source pipeline 6. The fluid inlet 2.2 of the pneumatic pump 2 is sealed and connected to the water outlet 1.1 of the main water collection pipe 1, and the fluid outlet 2.3 of the pneumatic pump 2 is sealed and connected to the circulating water return network 7 in the polysilicon production system. The pneumatic pump 2 pressurizes the drainage from the hanging plates 4 collected in the main water collection pipe 1 and transports it to the circulating water return network 7, realizing the recycling and reuse of the drainage from the hanging plates 4. The pneumatic pump 2 is also connected to an exhaust pipeline 2.4 for discharging the depressurized gas.

[0028] The circulating water return pipe network 7 is the main circulating water return pipe in the polysilicon production where the heat exchanger 3 is located. The fluid outlet 2.3 of the pneumatic pump 2 is directly connected to the main circulating water return pipe through a pipe, so that the external drainage of the recovered hanging plate 4 is mixed with the circulating water in the main circulating water return pipe and then transported together to the common system of polysilicon production for unified treatment.

[0029] Preferably, the pipeline path of the main water collection pipe 1 is adapted to each drainage point, and the diameter of the main collection pipe is determined according to the total flow rate of the external drainage of each hanging piece 4, so as to meet the requirement of non-retention collection of the external drainage of the hanging piece 4. It is generally advisable to select a pipe with a diameter of DN50~DN80 for the main water collection pipe 1.

[0030] Example 2 The difference between this embodiment and Embodiment 1 is that, in reference to Figure 2 The nitrogen pipeline 5 is connected to the nitrogen storage tank 8 or nitrogen pipeline network 13 in the polysilicon production system for storing surplus industrial nitrogen; the instrument gas source pipeline 6 is connected to the instrument gas source storage tank 10 or instrument gas pipeline network 14 in the polysilicon production system for storing surplus industrial instrument gas.

[0031] In this embodiment, the pneumatic pump 2 utilizes the surplus industrial gas source to provide driving power, replacing the electric drive mode of the traditional electric pump, thereby realizing the resource utilization of the surplus industrial gas source (nitrogen source or instrument gas source) of polysilicon production enterprises and reducing the power consumption in the polysilicon production process.

[0032] In practice, the two gas sources can be flexibly switched through the gas source switching valve. When the pressure in the nitrogen storage tank 8 is too low, the gas source will be automatically switched to the instrument gas source pipeline 6 to ensure continuous operation of the system.

[0033] Example 3 Compared with Examples 1 and 2, the only difference in this embodiment is that a flow sensor 11 is installed on the pipe between the outlet 1.1 of the main water collection pipe 1 and the fluid inlet 2.2 of the pneumatic pump 2. (Refer to...) Figure 2 The flow sensor 11 is used to monitor the collection flow rate of the external drainage of the hanging plate 4 in real time, so as to adjust the driving air source pressure of the pneumatic pump 2 according to the flow rate change and optimize the delivery efficiency.

[0034] Example 4 This embodiment is a further optimization of embodiment 5, the difference being that the flow sensor 11 is connected to the air source control valve of the pneumatic pump 2.

[0035] In practical implementation, the flow sensor 11 and the pneumatic pump 2 can be connected to the DCS (control system) of the polysilicon production. When the flow sensor 11 detects that the drainage flow rate of the hanging plate 4 is lower than the preset threshold, the flow sensor 11 simultaneously sends a corresponding signal to the DCS. After analysis, the DCS sends a signal to the pneumatic pump 2 to reduce the valve opening on the drive air supply pipeline, automatically reducing the opening of the corresponding valve on the pneumatic pump 2 to reduce the drive air supply. When the flow rate is higher than the preset threshold, the opening of the air source control valve is automatically increased to increase the drive air supply, realizing the adaptive adjustment of the delivery capacity of the pneumatic pump 2, which facilitates the realization of automated control.

[0036] The flow sensor 11 is preferably a turbine-type flow sensor 11, which can monitor the instantaneous flow and cumulative flow of external drainage in real time, and output the signal to the display screen of the control cabinet so that the operator can keep track of the amount of water recovered in real time.

[0037] In this embodiment, the flow sensor 11 is connected to the air source control valve of the pneumatic pump 2. When the flow sensor 11 detects that the instantaneous flow rate is greater than a preset value, the control cabinet sends a signal to increase the opening of the air source control valve, thereby increasing the delivery capacity of the pneumatic pump 2. When the instantaneous flow rate is less than the preset lower limit, the opening of the air source control valve decreases, thereby reducing air consumption. When the flow rate fluctuates abnormally, an alarm signal is automatically issued to prompt the operator to check whether the pipeline is blocked or whether the mounting plate 4 is leaking.

[0038] Example 5 The only difference between this embodiment and embodiments 1-4 is that the pneumatic pump 2 is a steam condensate pneumatic pump. The fluid delivery channel of this steam condensate pneumatic pump is adapted to the water quality characteristics of the external drainage of the hanging plate 4, and its driving air pressure adjustment range matches the conventional air supply pressure of the nitrogen source or instrument air source, ensuring stable delivery of the external drainage of the hanging plate 4.

[0039] Example 6 Compared with Examples 1-5, the only difference in this embodiment is that the laying path of the main water collection pipe 1 covers several drainage points of the hanging plates 4, as shown in the reference. Figure 1 , Figure 3 The illustration shows the laying path of the main water collection pipe 1, which covers three drainage points of the mounting brackets 4. The external drainage ends of the mounting brackets 4 are connected to the main water collection pipe 1 via inclined pipes 12. (See reference) Figure 3 Alternatively, the external drainage end of the hanging plate 4 can be connected to the main water collection pipe 1 via a vertical pipe.

[0040] Example 7 To facilitate public understanding of this utility model, this embodiment takes a superior heat exchanger fin water recycling system for polycrystalline silicon production as an example for further explanation.

[0041] refer to Figure 3 , 4The system includes a water collection main pipe 1 and a pneumatic pump 2. The water collection main pipe 1 is laid at the external drainage end of the hanging plate 4 of the heat exchanger 3, and the water collection main pipe 1 corresponds one-to-one with the external drainage points of all the hanging plates 4 of the heat exchanger 3 and is connected by pipes.

[0042] The medium inlet of the heat exchanger 3 is connected to the steam supply pipeline 9. The steam heats the material passing through the heat exchanger. After heat exchange, the steam becomes condensate, and the condensate is sent to the circulating water return pipeline 7.

[0043] The pneumatic pump 2 has an air source interface 2.1 at its air inlet, which is used to connect to the nitrogen pipeline 5 or the instrument air source pipeline 6. The fluid inlet 2.2 of the pneumatic pump 2 is sealed and connected to the water outlet 1.1 of the main water collection pipe 1, and the fluid outlet 2.3 of the pneumatic pump 2 is sealed and connected to the circulating water return network 7 in the polysilicon production system. The pneumatic pump 2 pressurizes the water collected in the main water collection pipe 1 and then transports it to the circulating water return network 7. The pneumatic pump 2 is also connected to an exhaust pipeline 2.4 for discharging the depressurized gas.

[0044] In this embodiment, the diameter of the main water collection pipe 1 is DN50~DN80. The specific diameter is determined based on the number of fins 4 on the heat exchanger 3 and the drainage capacity of a single set of fins 4. For example, for a system with 3 sets of fins 4 (each set has a drainage capacity of 1.2~1.5 m³ / hour),... 3 The heat exchanger 3 and the main water collection pipe 1 are selected with a diameter of DN50 to ensure that the water flow velocity in the pipe is controlled at 0.5m / s, which avoids water accumulation caused by too low flow velocity and prevents pipe wear caused by too high flow velocity. In this embodiment, the nitrogen pipeline 5 is connected to the nitrogen pipeline network 13 in the polysilicon production system, which stores surplus industrial nitrogen; the instrument gas supply pipeline 6 is connected to the instrument gas pipeline network 14 in the polysilicon production system, which stores surplus industrial instrument gas. The working pressure of the nitrogen pipeline network 13 is 0.7 MPa, and the working pressure of the instrument gas pipeline network 14 is 0.6 MPa, both of which meet the driving pressure requirements of the pneumatic pump 2. A gas source switching valve allows for flexible switching between the two gas sources. When the pressure in the nitrogen pipeline network 13 is too low, the system automatically switches to the instrument gas supply pipeline 6 to ensure continuous system operation.

[0045] In this embodiment, a flow sensor 11 for detecting the flow rate of fluid in the pipe is installed on the pipe connected to the rear end of the pneumatic pump 2. In this embodiment, the pneumatic pump 2 is a steam condensate pneumatic pump 2. Its pump body is made of 304 stainless steel, and the seals are made of heat-resistant fluororubber, which can withstand the temperature (50~100℃) and water quality characteristics (pH value of 6~9, containing trace silica particles) of the external drainage of the mounting plate 4. The rated flow rate of the pump is 5~6 m³ / h. 3With a capacity of / h and a maximum head of 50m, it can meet the needs of transporting external drainage to the circulating water return network 7 (relative height difference of 8m), and the gas-liquid ratio can be adjusted to 1:3 to reduce gas waste.

[0046] In this embodiment, the laying path of the main water collection pipe 1 covers several drainage points of the hanging plates 4, and the external drainage ends of the hanging plates 4 are connected to the main water collection pipe 1 via an inclined pipe 12. The inclined pipe 12 is made of DN25 stainless steel, which accelerates the external drainage flow through gravity and avoids water accumulation in the pipe. At the same time, the inclined pipe 12 is connected to the drainage ends of the hanging plates 4 by a union joint and to the main water collection pipe 1 by welding. All connections are treated with anti-corrosion measures to ensure a service life of ≥5 years.

[0047] During system operation, the external drainage generated by the hanging plate 4 flows into the main water collection pipe 1 via the inclined pipe 12. The flow sensor 11 monitors the flow rate in real time and feeds it back to the control system. The control system adjusts the air supply of the pneumatic pump 2 according to the flow rate. The pneumatic pump 2 pressurizes the external drainage and sends it into the circulating water return network 7, realizing the recycling and reuse of water resources. In actual application, the system can recover an average of 85~110m³ of water per day. 3 Water resource utilization rate is increased by more than 30%, and due to the use of surplus industrial gas source, annual electricity costs are saved by about 0.5 to 10,000 yuan.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A heat exchanger fin water recycling system for polycrystalline silicon production, characterized in that: It includes a water collection main pipe (1) and a pneumatic pump (2). The water collection main pipe (1) is laid at the external drainage end of the hanging plates (4) of the heat exchanger (3), and the water collection main pipe (1) corresponds one-to-one with the external drainage points of all the hanging plates (4) of the heat exchanger (3) and is connected by pipes. The air inlet of the pneumatic pump (2) is provided with an air source interface (2.1). The air source interface (2.1) is used to connect to the nitrogen pipeline (5) or the instrument air source pipeline (6). The fluid inlet (2.2) of the pneumatic pump (2) is sealed and connected to the water outlet (1.1) of the water collection pipe (1). The fluid outlet (2.3) of the pneumatic pump (2) is sealed and connected to the circulating water return pipe network (7) in the polysilicon production system. The pneumatic pump (2) drains the hanging plate (4) collected in the water collection pipe (1) and pressurizes it before transporting it to the circulating water return pipe network (7).

2. The heat exchanger fin water recycling system for polycrystalline silicon production according to claim 1, characterized in that: The diameter of the main water collection pipe (1) is DN50~DN80.

3. The heat exchanger fin water recycling system for polycrystalline silicon production according to claim 1, characterized in that: The nitrogen pipeline (5) is connected to the nitrogen storage tank (8) or nitrogen pipeline network (13) in the polysilicon production system for storing surplus industrial nitrogen; the instrument gas source pipeline (6) is connected to the instrument gas source storage tank (10) or instrument gas pipeline network (14) in the polysilicon production system for storing surplus industrial instrument gas.

4. A heat exchanger fin water recycling system for polycrystalline silicon production according to claim 1, characterized in that: A flow sensor (11) is installed on the pipe between the outlet (1.1) of the main water collection pipe (1) and the fluid inlet (2.2) of the pneumatic pump (2).

5. A heat exchanger (3) finned (4) water recycling system for polycrystalline silicon production according to claim 1, characterized in that: The flow sensor (11) is connected to the air source control valve of the pneumatic pump (2).

6. A heat exchanger fin water recycling system for polycrystalline silicon production according to claim 1, characterized in that: The pneumatic pump (2) is a steam condensate pneumatic pump (2).

7. A heat exchanger fin water recycling system for polycrystalline silicon production according to claim 1, characterized in that: The laying path of the main water collection pipe (1) covers several drainage points of the hanging plates (4), and the drainage ends of the hanging plates (4) are connected to the main water collection pipe (1) through inclined pipes (12) or vertical pipes.

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