A device for increasing the pressure of a water system of a polysilicon tail gas recovery adsorption column

Abstract

The utility model discloses a device of improving polysilicon tail gas recovery adsorption tower water system pressure. The device sets up expansion tank in the cold and hot water circulation system in water pump import end, and injects compressed nitrogen gas to expansion tank through nitrogen compressor, forms independent pressure boost buffer area to improve the pressure before pump. System is equipped with sensor and control device, realizes the accurate regulation of gas injection, prevents the pump and water vaporization effectively, improves hot water energy density and heat transfer efficiency, improves the stability and reliability of adsorption / regeneration process. The device simple structure, pressure regulating response is quick, can improve water pump import pressure, prevent the pump and water vaporization phenomenon, improve hot water energy density and heat transfer efficiency, improve adsorption tower adsorption / regeneration stability and system operation reliability, adapt to multi -tower parallel system, facilitate industrialized popularization and application.

Description

Technical Field

[0001] This utility model relates to the field of polycrystalline silicon technology, and in particular to a device for increasing the pressure of a water system in a polycrystalline silicon tail gas recovery adsorption tower. Background Technology

[0002] In polysilicon production, activated carbon is widely used in the adsorption towers of the tail gas recovery system for hydrogen purification and regeneration. To maintain temperature control in the adsorption towers, a hot and cold water circulation system is typically installed. This system includes a hot water heater, cooler, water pump, adsorption tower, and an expansion tank for pressure buffering. Current technology often uses low-pressure steam (approximately 0.3–0.4 MPa) to maintain pressure in the expansion tank, thereby increasing the water pump inlet pressure and suppressing water vaporization. However, in actual operation, especially in multi-tower parallel systems, insufficient water supply pressure, water hammer, or pump failure often occur in the furthest adsorption tower, severely affecting adsorption and regeneration efficiency. Utility Model Content

[0003] This utility model provides a device for increasing the water supply pressure of an adsorption tower water system. To solve the above problems, this utility model provides the following technical solution: An apparatus for increasing the water supply pressure of a polycrystalline silicon tail gas recovery adsorption tower water system includes an adsorption tower with a jacket structure on its exterior; the outlet of a heating hot water pump is sequentially connected to a hot water heater and the jacket structure of the adsorption tower, with the outlet of the jacket structure flowing back to the inlet of the heating hot water pump; the outlet of a cooling hot water pump is sequentially connected to a hot water cooler and the jacket structure of the adsorption tower, with the outlet of the jacket structure flowing back to the inlet of the cooling hot water pump; an expansion tank is provided on the inlet pipe of the heating hot water pump, and a water replenishment tank is provided on the inlet branch pipe of the expansion tank for replenishing liquid to the heating circuit to maintain the liquid level; an expansion tank is provided on the inlet pipe of the cooling hot water pump; a compression device is connected to two of the expansion tanks respectively for injecting compressed gas into the expansion tanks to increase the pump inlet pressure.

[0004] Furthermore, the jacket structure includes a finned jacket tube and a half-tube jacket disposed outside the adsorption bed of the adsorption tower.

[0005] The above-mentioned adsorption tower structure not only improves the heat exchange capacity per unit area but also reduces energy consumption. It features a compact structure, mature manufacturing technology, and is suitable for the rapid temperature control requirements in polycrystalline silicon tail gas recovery applications. The purpose of this invention is to provide a method for increasing the water supply pressure of the adsorption tower water system. By introducing compressed gas into the expansion tank, continuous pressurization is achieved at the pump inlet, thereby overcoming the problems of slow reaction and unstable pressure in traditional low-pressure steam pressure maintenance methods, and improving system stability and adsorption efficiency. Simultaneously, a suitable device for implementing this method is also provided.

[0006] Furthermore, the compression device is a nitrogen compressor with an output pressure of 1.3 to 1.6 MPa.

[0007] This technical solution replaces the ordinary steam pressure source with an industrial-grade nitrogen compressor, improving the stability and service life of the gas source, reducing operation and maintenance costs, and avoiding the adverse effects of steam condensate on the system.

[0008] Furthermore, the expansion tank is equipped with a pressure sensor and a liquid level sensor for monitoring the internal gas-liquid state.

[0009] This technical solution enhances the water system's sensing capabilities during actual operation, facilitating the implementation of automatic control strategies and providing early warning of system faults. By introducing nitrogen compressed gas into the expansion tank of the adsorption tower water system, this invention effectively increases the pump inlet pressure, solving the problem of insufficient remote water supply pressure and preventing water vaporization and pump vibration-induced shutdown. Simultaneously, by incorporating buffer branches and three-way valves in the hot and cold water switching path, it achieves pressure transition and shock resistance during system switching, significantly improving the operational stability and equipment lifespan during adsorption tower regeneration. Compared with existing technologies, this invention offers advantages such as fast pressure regulation response, high pressure control accuracy, strong anti-fluctuation capability, adaptability to multi-tower parallel systems, and simple structure.

[0010] Compared with the prior art, this utility model has the following technical effects: This invention effectively increases the inlet pressure of the heating and cooling water pumps by introducing nitrogen compressed gas into the expansion tank of the adsorption tower water system. This solves the problems of pump drop, water vaporization, and flow fluctuation caused by pressure drop during the water supply process of the remote adsorption tower in traditional systems, and significantly improves the stability of water supply.

[0011] The increased system pressure allows hot water at 180–190°C to remain stable under superheated conditions, significantly raising the boiling point and preventing sudden boiling caused by local disturbances, bubble formation, or pressure fluctuations. This improves the safety and stability of the hot water circulation system. Simultaneously, high-pressure hot water has a higher energy density, storing more heat energy per unit volume, thus improving heat transfer efficiency and making the heating of the activated carbon bed during the adsorption tower regeneration process more efficient and uniform.

[0012] Compared with the traditional method of relying on low-pressure steam for pressure maintenance, this utility model uses nitrogen compressed gas source, which has the advantages of fast pressure regulation response, high control accuracy and strong system anti-disturbance capability. It is suitable for the working conditions of frequent switching and continuous operation in multi-tower parallel system. The overall structure is simple, easy to arrange and convenient for industrial implementation. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of an embodiment of the present utility model; Figure 2 This is a schematic diagram of the adsorption tower in the device of this utility model embodiment; Figure 3 This is a schematic diagram of the nitrogen compressor in the device of this utility model embodiment. Detailed Implementation

[0014] The following will describe the technology of the embodiments of the present utility model clearly and completely with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present utility model. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present utility model can be combined with each other.

[0015] Reference Figure 1 This embodiment provides a device for increasing the pressure of the water system in a hydrogen adsorption tower for tail gas recovery. The adsorption tower 1 is used to adsorb hydrogen containing impurities and output pure hydrogen. Its structure includes the adsorption tower body, a finned jacketed tube 101, and a half-tube jacket 102. Cold / hot water runs within the finned jacketed tube 101 and the half-tube jacket 102, cooling / heating the internal activated carbon through the surface of the heat exchange tube and the extended fins. The finned jacketed tube 101 is spirally wrapped to improve heat exchange efficiency. The half-tube jacket 102 is located in the lower region of the adsorption tower to expand the effective heat exchange area and achieve rapid temperature control switching.

[0016] The hot water heater 2 is used to heat the hot water for regeneration. The hot water is heated to 180-190°C by steam at 1.0MPa to 1.2MPa and then introduced into the finned jacket tube 101 and the half-pipe jacket 102 of the adsorption tower.

[0017] The hot water cooler 3 uses an air cooler or a water cooler to cool the water to 40°C, and then introduces it into the finned jacket tube 101 and the half-pipe jacket 102 of the adsorption tower.

[0018] The heating water pump 4 is used for the circulation of hot water flow. The hot water is heated by the hot water heater 2 after passing through the outlet of the heating water pump 4, and then sent to the adsorption tower 1 for heating and regeneration, and then returned to the inlet of the heating water pump 1.

[0019] The cooling hot water pump 5 is used for the circulation of cold water. The cold water is pressurized by the cooling hot water pump 5, cooled by the hot water cooler 3, and then sent to the adsorption tower 1 for cooling and adsorption, before returning to the inlet of the cooling hot water pump 5.

[0020] Furthermore, the system also includes a water replenishment tank 6, an expansion tank 7, and a nitrogen compressor 8. The system has two expansion tanks 7, respectively located on the inlet pipes of the heating hot water pump 4 and the cooling hot water pump 5, to respectively increase the inlet pressure of the two pumps. The water replenishment tank 6 is located in the hot water circulation loop and connected to the inlet branch pipe of the heating hot water pump 4, used to replenish the hot water loop and maintain the liquid level. The output end of the nitrogen compressor 8 is connected to the two expansion tanks 7 via branch pipes to achieve synchronous pressurization control of the two loops.

[0021] The nitrogen compressor 8 pressurizes the inlet expansion tanks 7 of the heating water pump 4 and the cooling water pump 5 respectively, thereby increasing the inlet pressure of the heating water pump 4 and the cooling water pump 5. The increase in inlet pressure makes it easier for the pump to draw in the fluid and push it to the outlet, thereby generating a higher outlet pressure. On the other hand, maintaining a certain pressure in the expansion tank 7 before the heating water pump 4 prevents the hot water from depressurizing and vaporizing, thereby improving the working efficiency of the pump and helping the pump to better cope with the demand of high pressure and high flow rate.

[0022] The nitrogen compressor 8 in this embodiment is a Z-type, single-row, reciprocating piston single-stage compressor. The compressor is lubricated by pressurized oil in the crank-connecting rod mechanism and by oilless lubrication of the cylinder packing. The compressor and medium are cooled by water. The compressor, motor, filter, cooler, safety valve, check valve, and PLC control cabinet are integrated on a skid-mounted base, forming a complete unit that is easy to install, simple to use, and operates smoothly and reliably.

[0023] In the implementation of this utility model, further as follows: Figure 3 As shown, nitrogen is introduced from a steel cylinder and, after multi-stage pressure reduction, enters nitrogen compressor 8 for pressurization. This compressor is a Z-type, single-row, reciprocating piston single-stage compression structure with a skid-mounted assembly, offering high compression efficiency and stable operation. Its lubrication method is oil lubrication of the crank-connecting rod mechanism, while the cylinder packing is oil-free lubricated. The medium is cooled by water.

[0024] The compressed high-temperature nitrogen gas first enters Figure 3 The gas cooler shown is a horizontal heat exchanger with upper and lower connecting pipes. It is used to reduce the temperature of compressed nitrogen and prevent the high-temperature gas from causing thermal shock to the downstream system. After cooling, the nitrogen enters the expansion tank 7 located at the inlet of the water pump after passing through a check valve and a pressure gauge, thereby maintaining and regulating the pressure at the front end of the water pump. Figure 3 The expansion tank 7 device is not shown. It is usually connected to the gas output end through a branch pipe and arranged in the main water channel of the system.

[0025] like Figure 1 As shown, the working principle of the device includes: When the nitrogen compressor 8 pressurizes the inlet expansion tank 7 of the heating water pump 4 and the cooling water pump 5 to increase the pump inlet pressure, the entire water system will undergo a series of changes and cycles during its operation: Compressor function: Nitrogen compressor 8 is responsible for compressing nitrogen gas from 0.7MPa to 1.4MPa; Expansion tank function: After the pressure in expansion tank 7 increases, it is transmitted to the water pump inlet through the pipeline, thereby increasing the inlet pressure; Fluid transport: After the inlet pressure of the water pump is increased, the working efficiency and transport capacity of the pump are improved, and the pump outlet pressure can reach more than 1.7MPa; Heat transfer: The cold / hot water pumped by the pump is sent to the adsorption tower 1 for heat exchange after passing through heater 2 or cooler 3 respectively; Reflux circulation: Hot / cold water returns to the water pump inlet after heat exchange in the jacket of the adsorption tower, forming a closed loop to ensure the efficient and stable operation of the adsorption tower.

[0026] Furthermore, in this embodiment, the expansion tank is pressurized using a nitrogen compressor, ensuring that the hot water in the system remains in a stable liquid state at 180–190°C. This significantly increases its boiling point and prevents boiling. Increased pressure enhances the hot water's heat storage capacity, allowing it to carry more heat energy per unit volume. This results in less heat loss during hot water transfer, higher heat transfer efficiency, and effectively improved heat utilization and system operational stability during the adsorption tower regeneration process.

Claims

1. A device for increasing the pressure of a water system in a polycrystalline silicon tail gas recovery adsorption tower, characterized in that, The system includes an adsorption tower (1) with a jacket structure on its exterior; the outlet of a heating hot water pump (4) is connected in sequence to a hot water heater (2) and the jacket structure of the adsorption tower (1), and the outlet of the jacket structure of the adsorption tower (1) flows back to the inlet of the heating hot water pump (4); the outlet of a cooling hot water pump (5) is connected in sequence to a hot water cooler (3) and the jacket structure of the adsorption tower (1), and the outlet of the jacket structure of the adsorption tower (1) flows back to the inlet of the cooling hot water pump (5); an expansion tank (7) is provided on the inlet pipe of the heating hot water pump (4), and a water replenishment tank (6) is provided on the inlet branch pipe of the expansion tank (7) for replenishing liquid to the heating circuit to maintain the liquid level; an expansion tank (7) is provided on the inlet pipe of the cooling hot water pump (5); a compression device is connected to the two expansion tanks (7) respectively for injecting compressed gas into the expansion tanks (7) to increase the pump inlet pressure.

2. The device for increasing the pressure of the water system in the polycrystalline silicon tail gas recovery adsorption tower according to claim 1, characterized in that, The jacket structure includes a finned jacket tube (101) and a half-tube jacket (102) disposed outside the adsorption bed of the adsorption tower (1).

3. The device for increasing the pressure of a water system in a polycrystalline silicon tail gas recovery adsorption tower according to claim 1, characterized in that, The compression device is a nitrogen compressor (8).

4. The device for increasing the pressure of the water system in the polycrystalline silicon tail gas recovery adsorption tower according to claim 3, characterized in that, The nitrogen compressor (8) compresses nitrogen to 1.3 to 1.6 MPa.

5. The device for increasing the pressure of the water system in the polycrystalline silicon tail gas recovery adsorption tower according to claim 1, characterized in that, The expansion tank (7) is equipped with a pressure sensor and a liquid level sensor.

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