Cooling system of reduction furnace

Abstract

The utility model provides a cooling system of a reduction furnace, and aims to solve the technical problems of long cooling time and large tail gas pressure fluctuation of an existing silicon rod cooling mode. The system comprises: a cold hydrogen circulation unit, an inlet of which is connected with a gas outlet end of a reduction furnace and an outlet of which is connected with a gas inlet end of the reduction furnace; wherein the cold hydrogen circulating unit comprises a first condensing device, a first compressor and a second condensing device, and the first condensing device, the first compressor, the second condensing device and the reduction furnace form a communicated circulating structure through a hydrogen circulating header pipe. After being blown to the tail gas for recovery, the recovered hydrogen can be recycled to the reduction furnace after being subjected to primary condensation, compression and secondary condensation in front of the machine, so that the process is simplified, the cooling capacity can be saved, the silicon rod cooling time is shortened, and the system stability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of silicon rod production, in particular to a reduction furnace cooling system. Background Art

[0002] After the reduction furnace's atmospheric deposition process completes, the silicon rods must be cooled before they meet furnace requirements. The current process involves shutting off the power supply after the silicon rods are disconnected from the trichlorosilane feed. Meanwhile, recovered hydrogen is blown through the reduction furnace into the exhaust system to cool the silicon rods. This approach not only takes a long time to cool, but also causes the exhaust gas volume in the recovery system to fluctuate continuously, leading to large fluctuations in exhaust pressure and impacting the reduction furnace's operation. Summary of the Invention

[0003] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a reduction furnace cooling system, which solves the technical problems of the existing silicon rod cooling method, such as long cooling time and large tail gas pressure fluctuations.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] A reduction furnace cooling system includes: a cold hydrogen circulation unit, whose inlet is connected to the gas outlet end of the reduction furnace, and the outlet is connected to the gas inlet end of the reduction furnace; wherein, the cold hydrogen circulation unit includes a first condensing device, a first compressor and a second condensing device, and the first condensing device, the first compressor, the second condensing device and the reduction furnace form a connected circulation structure through a hydrogen circulation main pipe.

[0006] The utility model recovers hydrogen and blows it into the tail gas for recovery. After the recovery, it only needs to go through the first stage of condensation and compression before the machine and the second stage of condensation after the machine before it can be recycled to the reduction furnace. This not only simplifies the process, but also saves cooling capacity, reduces the cooling time of silicon rods, and improves system stability.

[0007] Optionally, the gas outlet end of the reduction furnace is connected to the inlet of the first condensing device through a first pipe, the outlet of the first condensing device is connected to the inlet of the first compressor through a second pipe, the outlet of the first compressor is connected to the inlet of the second condensing device through a third pipe, and the outlet of the second condensing device is connected to the gas inlet end of the reduction furnace through a fourth pipe.

[0008] Optionally, the first condensing device adopts primary condensation, and the second condensing device adopts secondary condensation.

[0009] Optionally, the cooling system further comprises a separation unit, wherein the inlet of the separation unit is connected to the gas outlet of the reduction furnace, and the outlet is connected to the gas inlet of the reduction furnace.

[0010] Optionally, the separation unit includes corresponding connecting pipes of a third condensing device, a second compressor, a fourth condensing device, an absorption device and an adsorption device, and the third condensing device, the second compressor, the fourth condensing device, the absorption device, the adsorption device and the reduction furnace are connected through corresponding connecting pipes to form an interconnected circulation structure.

[0011] Optionally, the gas outlet end of the reduction furnace is connected to the inlet of the third condensing device through a fifth pipe, the outlet of the third condensing device is connected to the inlet of the second compressor through a sixth pipe, the outlet of the second compressor is connected to the inlet of the fourth condensing device through a seventh pipe, the outlet of the fourth condensing device is connected to the inlet of the absorption device through an eighth pipe, the outlet of the absorption device is connected to the inlet of the adsorption device through a ninth pipe, and the outlet of the adsorption device is connected to the gas inlet end of the reduction furnace through a tenth pipe.

[0012] Optionally, the third condensing device and the fourth condensing device both adopt six-stage condensation.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The utility model provides a new cooling method. After the recovered hydrogen is blown to the tail gas recovery, it only needs to undergo a first-stage condensation and compression before the machine and a second-stage condensation after the machine to meet the separation task, and can be recycled and reused in the reduction furnace. The utility model not only simplifies the process, but also saves cooling capacity, reduces the cooling time of silicon rods, and improves system stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 It is a structural diagram of the present utility model.

[0017] Figure numerals: 1, reduction furnace; 21, first condensing device; 22, first compressor; 23, second condensing device; 2a, first pipeline; 2b, second pipeline; 2c, third pipeline; 2d, fourth pipeline; 31, third condensing device; 32, second compressor; 33, fourth condensing device; 34, absorption device; 35, adsorption device; 3a, fifth pipeline; 3b, sixth pipeline; 3c, seventh pipeline; 3d, eighth pipeline; 3e, ninth pipeline; 3f, tenth pipeline. DETAILED DESCRIPTION

[0018] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0019] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "end", "side", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this utility model application, "plurality" means two or more, unless otherwise specifically defined.

[0021] In the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection, indirect connection through an intermediate medium, or internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0022] In the embodiments of the present utility model application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being "above", "above", and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below", and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0023] The disclosure below provides many different embodiments or examples for implementing different structures of the embodiments of the present invention. In order to simplify the disclosure of the embodiments of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the embodiments of the present invention. In addition, the embodiments of the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0024] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, the embodiment of the present invention provides a reduction furnace cooling system, which includes a reduction furnace 1, a cold hydrogen circulation unit, and a separation unit. The inlets of the cold hydrogen circulation unit and the separation unit are respectively connected to the gas outlet of the reduction furnace 1, and the outlets of the cold hydrogen circulation unit and the separation unit are respectively connected to the gas inlet of the reduction furnace.

[0026] The cold hydrogen circulation unit includes a first condensing device 21, a first compressor 22, a second condensing device 23, and a hydrogen circulation main pipe. The first condensing device 21, the first compressor 22, the second condensing device 23, and the reduction furnace 1 are interconnected through the hydrogen circulation main pipe to form a circulation structure. Recovered hydrogen is blown into the reduction furnace 1, and the tail gas is recovered and then flows through the first condensing device 21, the first compressor 22, and the second condensing device 23 before being returned to the reduction furnace 1.

[0027] Specifically, the gas outlet of the reduction furnace 1 is connected to the inlet of the first condensing device 21 via a first pipe 2a. The outlet of the first condensing device 21 is connected to the inlet of the first compressor 22 via a second pipe 2b. The outlet of the first compressor 22 is connected to the inlet of the second condensing device 23 via a third pipe 2c. The outlet of the second condensing device 23 is connected to the gas inlet of the reduction furnace 1 via a fourth pipe 2d. Alternatively, the hydrogen circulation main pipe includes the first pipe 2a, the second pipe 2b, the third pipe 2c, and the fourth pipe 2d. The first pipe 2a has one end connected to the gas outlet of the reduction furnace 1 and the other end connected to the inlet of the first condensing device 21. The second pipe 2b has one end connected to the outlet of the first condensing device 21 and the other end connected to the inlet of the first compressor 22. The third pipe 2c has one end connected to the outlet of the first compressor 22 and the other end connected to the second condensing device 23. The fourth pipe 2d has one end connected to the outlet of the second condensing device 23 and the other end connected to the inlet of the reduction furnace 1.

[0028] Optionally, the first condensing device 21 adopts a pre-condensation stage; and the second condensing device 23 adopts a post-condensation stage.

[0029] For example, a shut-off valve can be added in front of the exhaust main valve of a single reduction furnace, and hydrogen can be transported to the hydrogen circulation main pipe in the shutdown state through pipeline configuration. The first condensing device 21, the first compressor 22, the second condensing device 23 and the reduction furnace 1 form a reduction shutdown cold hydrogen circulation system through the hydrogen circulation main pipe.

[0030] In one implementation scenario, the recovered hydrogen is blown to the tail gas recovery and then enters the first condensing device 21 through the first pipe 2a for cooling and then enters the first compressor 22. The first compressor 22 pressurizes the shutdown hydrogen to 0.9 MPa and then sends it to the second condensing device 23. The second condensing device 23 heats the shutdown hydrogen to 20°C and then sends it to the reduction furnace 1 through the fourth pipe 2d. The gas volume fluctuation during the whole process has little impact on the system, which is conducive to improving the stability of the system during operation and reducing the occurrence of quality accidents.

[0031] The separation unit includes a third condensing device 31, a second compressor 32, a fourth condensing device 33, an absorber 34, an adsorption device 35, and corresponding connecting pipes. The third condensing device 31, the second compressor 32, the fourth condensing device 33, the absorber 34, the adsorption device 35, and the reduction furnace 1 are connected via corresponding connecting pipes to form a circulation structure. The hydrogen recovered from the tail gas passes through the third condensing device 31, the second compressor 32, the fourth condensing device 33, the absorber 34, and the adsorption device 35 in sequence before being returned to the reduction furnace 1.

[0032] Specifically, the gas outlet end of the reduction furnace 1 is connected to the inlet of the third condensing device 31 through the fifth pipe 3a, the outlet of the third condensing device 31 is connected to the inlet of the second compressor 32 through the sixth pipe 3b, the outlet of the second compressor 32 is connected to the inlet of the fourth condensing device 33 through the seventh pipe 3c, the outlet of the fourth condensing device 33 is connected to the inlet of the absorption device 34 through the eighth pipe 3d, the outlet of the absorption device 34 is connected to the inlet of the adsorption device 35 through the ninth pipe 3e, and the outlet of the adsorption device 35 is connected to the gas inlet end of the reduction furnace 1 through the tenth pipe 3f.

[0033] Optionally, the third condensing device 31 and the fourth condensing device 33 both adopt six-stage condensation, with two first-stage condensers respectively arranged in front of the machine and behind the machine.

[0034] This utility model primarily optimizes the load of the main hydrogen recovery system. As an implementation scenario, a shut-off valve is added in front of the exhaust main valve of a single reduction furnace, and piping is routed to the shutdown hydrogen circulation main pipe, which is then connected to a separate reduction shutdown hydrogen system. A compressor pressurizes the shutdown hydrogen to 0.9 MPa, heats it through a circulating water cooler, a heat exchanger, and a -10°C cooler. Finally, the shutdown hydrogen is heated to 20°C and delivered to the reduction system through the shutdown cold hydrogen pipeline, thereby minimizing the impact of gas volume fluctuations during shutdown on the system.

[0035] This new system can save refrigerant costs, lower the temperature of cold hydrogen during shutdown, and provide a more stable gas volume, further reducing non-productive time and increasing overall output. Furthermore, one hydrogen recovery compressor can be used as a standby, improving the safety and stability of the system during operation and reducing the occurrence of quality accidents.

[0036] Parts not described in detail in this embodiment are well-known technologies in the art.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection of the claims.

Claims

1. A reduction furnace cooling system, characterized in that: include: a cold hydrogen circulation unit, the inlet of which is connected to the gas outlet of the reduction furnace, and the outlet of which is connected to the gas inlet of the reduction furnace; The cold hydrogen circulation unit includes a first condensing device, a first compressor and a second condensing device. The first condensing device, the first compressor, the second condensing device and the reduction furnace form a circulating structure connected through a hydrogen circulation main pipe.

2. The reduction furnace cooling system according to claim 1, characterized in that: The gas outlet end of the reduction furnace is connected to the inlet of the first condensing device through a first pipe, the outlet of the first condensing device is connected to the inlet of the first compressor through a second pipe, the outlet of the first compressor is connected to the inlet of the second condensing device through a third pipe, and the outlet of the second condensing device is connected to the gas inlet end of the reduction furnace through a fourth pipe.

3. The reduction furnace cooling system according to claim 1 or 2, characterized in that: The first condensing device adopts one-stage condensation, and the second condensing device adopts two-stage condensation.

4. The reduction furnace cooling system according to claim 1, characterized in that: The cooling system further comprises a separation unit, the inlet of the separation unit is connected to the gas outlet end of the reduction furnace, and the outlet is connected to the gas inlet end of the reduction furnace.

5. The reduction furnace cooling system according to claim 4, characterized in that: The separation unit includes a third condensing device, a second compressor, a fourth condensing device, an absorption device and corresponding connecting pipes of the adsorption device. The third condensing device, the second compressor, the fourth condensing device, the absorption device, the adsorption device and the reduction furnace are connected through corresponding connecting pipes to form an interconnected circulation structure.

6. The reduction furnace cooling system according to claim 5, characterized in that: The gas outlet end of the reduction furnace is connected to the inlet of the third condensing device through the fifth pipe, the outlet of the third condensing device is connected to the inlet of the second compressor through the sixth pipe, the outlet of the second compressor is connected to the inlet of the fourth condensing device through the seventh pipe, the outlet of the fourth condensing device is connected to the inlet of the absorption device through the eighth pipe, the outlet of the absorption device is connected to the inlet of the adsorption device through the ninth pipe, and the outlet of the adsorption device is connected to the gas inlet end of the reduction furnace through the tenth pipe.

7. The reduction furnace cooling system according to claim 5 or 6, characterized in that: The third condensing device and the fourth condensing device both adopt six-stage condensation.

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