A kind of reduction dry vacuum equipment and safety system

Abstract

The utility model provides a reduction dry vacuum equipment and a safety system, which relate to the field of silicon reduction process. The reduction dry vacuum equipment includes a dry buffer tank, whose buffer tank inlet pipe is connected to the inside of the reduction furnace; a Roots vacuum pump, which is connected to the buffer tank outlet pipe of the dry buffer tank; and a safety system, including: a nitrogen delivery pipeline, which is arranged on the buffer tank inlet pipe of the dry buffer tank, and a nitrogen flow meter and a nitrogen flow regulating valve are arranged on the nitrogen delivery pipeline; a sensor module, which has at least a temperature sensor and a pressure sensor, both of which are arranged inside the dry buffer tank; and a DCS module, which is connected to the nitrogen flow meter, the nitrogen flow regulating valve, the temperature sensor and the pressure sensor by signal, and controls the opening of the nitrogen flow regulating valve according to the temperature sensor, the pressure sensor and the nitrogen flow meter signal. The utility model reduces the risk of flash explosion of the equipment and improves the safety and stability.

Description

Technical Field

[0001] The utility model relates to the field of silicon reduction technology, in particular to a reduction dry vacuum equipment and a safety system. Background Art

[0002] Before the silicon reduction production process, the reduction furnace needs to be evacuated to keep it in a high vacuum state, remove excess harmful gases, and then fill it with inert gas as a protective gas. After that, the graphite heater in the reduction furnace is used to heat and melt the block polysilicon material placed in the quartz crucible to complete the production of single crystal silicon. During the production process of single crystal silicon, the reduction furnace must be continuously evacuated and continuously filled with inert protective gas.

[0003] Dry vacuum equipment is usually used to evacuate the reduction furnace. Dry vacuum equipment usually refers to vacuum pumps that do not use oil, water or other liquids as sealing or lubricating media. They are particularly useful in vacuum environments that require clean, oil-free and water-free conditions. Dry vacuum silicon powder buffer tanks are specially designed equipment for handling materials such as silicon powder that may cause damage to vacuum pumps. In dry vacuum equipment, the buffer tank plays a vital role. It can prevent silicon powder from directly entering the vacuum pump, thereby protecting the vacuum pump from wear or clogging, and also avoiding silicon powder from contaminating the vacuum pump oil.

[0004] In actual use, dry vacuum equipment needs to be used to clean the chassis after the reduction furnace is dismantled. At this time, the substances inhaled are not only simple harmful gases, but also flammable and explosive substances such as silicon powder, materials and other reaction products, which are prone to flash explosions in the dry vacuum silicon powder buffer tank. Existing dry vacuum equipment is difficult to monitor and prevent flash explosions of flammable and explosive substances, which increases the instability and safety risks of the production process. Utility Model Content

[0005] In order to solve the problem in the prior art that dry vacuum equipment is difficult to monitor and prevent flash explosions of flammable and explosive materials, thereby increasing the instability and safety risks of the production process, the utility model provides a reduced dry vacuum equipment and a safety system that can monitor the flash explosion risk of dry vacuum equipment in real time and automatically adjust for prevention.

[0006] The technical solution adopted by the utility model is:

[0007] A safety system comprising:

[0008] A nitrogen delivery pipeline is arranged on the inlet pipe of the closed container, and a nitrogen flow meter and a nitrogen flow regulating valve are arranged on the nitrogen delivery pipeline;

[0009] A sensor module, comprising at least a temperature sensor and a pressure sensor, both of which are arranged inside the sealed container; and

[0010] A DCS module is signal-connected to the nitrogen flow meter, the nitrogen flow regulating valve, the temperature sensor and the pressure sensor;

[0011] The DCS module generates a dynamic nitrogen flow threshold in real time according to the temperature sensor and pressure sensor signals. When the real-time flow value fed back by the nitrogen flow meter signal is less than the dynamic nitrogen flow threshold, the DCS module controls the nitrogen flow regulating valve to increase the opening, otherwise reduce the opening.

[0012] Furthermore, it also includes:

[0013] The explosion vent is arranged on the side wall of the closed container.

[0014] Furthermore, a bursting piece is arranged in the explosion vent.

[0015] Furthermore, the bursting disc has a diaphragm to prevent the medium from leaking out.

[0016] Furthermore, the closed container is a dry buffer tank.

[0017] A reduction dry vacuum device, comprising:

[0018] As in the safety system described above, the buffer tank inlet pipe of the dry buffer tank is connected to the interior of the silicon reduction furnace; and

[0019] A Roots vacuum pump is connected to a buffer tank outlet pipe of the dry buffer tank.

[0020] Furthermore, a dry filter is provided in the dry buffer tank.

[0021] Furthermore, the dry buffer tank has at least:

[0022] a tank body, in which the dry filter is arranged; and

[0023] A collecting bucket is arranged at the bottom of the tank body and communicated with the tank body.

[0024] Furthermore, a muffler is provided on the vacuum pump outlet pipe of the Roots vacuum pump.

[0025] The beneficial effects of the utility model are:

[0026] 1. The utility model sets a nitrogen delivery pipeline, a sensor module and a DCS module in the safety system, and relies on the DCS module to control the nitrogen flow meter, the nitrogen flow regulating valve, the temperature sensor and the pressure sensor to form a dynamic adjustment system for the nitrogen flow rate, thereby reducing the risk of flash explosion, improving the safety and stability of the equipment, and solving the problem in the prior art that it is difficult to monitor and prevent the flash explosion of flammable and explosive substances in dry vacuum equipment.

[0027] 2. The utility model also realizes full utilization of nitrogen and resource conservation by setting a DCS module to control a nitrogen flow meter, a nitrogen flow regulating valve, a temperature sensor and a pressure sensor to form a dynamic regulation system for nitrogen flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application 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 below. 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 paying creative work.

[0029] Figure 1 This is a schematic structural diagram of a dry vacuum device according to an embodiment of the present utility model.

[0030] Figure 2 It is a schematic diagram of the structure of the safety system of an embodiment of the utility model.

[0031] Reference numerals:

[0032] 100-dry buffer tank, 110-tank body, 114-dry filter, 120-collection barrel, 130-buffer tank inlet pipe, 140-buffer tank outlet pipe;

[0033] 200-sensor module, 210-temperature sensor, 220-pressure sensor;

[0034] 300-nitrogen delivery pipeline, 310-nitrogen flow meter, 320-nitrogen flow regulating valve;

[0035] 400-Roots vacuum pump, 410-vacuum pump inlet pipe, 420-vacuum pump outlet pipe, 422-muffler;

[0036] 500-DCS module;

[0037] 600-explosion vent, 610-bursting disc. DETAILED DESCRIPTION

[0038] In the description 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0039] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0040] The embodiments of the utility model are described in detail below with reference to the accompanying drawings.

[0041] See also Figure 1 The present embodiment provides a reduction dry vacuum device for evacuating a reduction furnace and cleaning a chassis after the reduction furnace is dismantled. The reduction dry vacuum device mainly includes: a Roots vacuum pump 400, a dry buffer tank 100 and a safety system.

[0042] The Roots vacuum pump 400 is the main power source of the vacuum equipment of this embodiment, providing the negative pressure required for vacuuming and cleaning the chassis. The Roots vacuum pump 400 is a dry mechanical vacuum pump, which realizes the vacuuming function through two synchronously counter-rotating rotors. The two rotors in the Roots vacuum pump 400 rotate synchronously in the opposite direction in the pump chamber, but they do not contact each other. The rotation of the rotors transports the gas from the suction port of the pump to the exhaust port, thereby realizing the vacuuming. Figure 1 As shown in , the vacuum pump inlet pipe 410 of the Roots vacuum pump 400 is connected to the buffer tank outlet pipe 140 of the dry buffer tank 100, and negative pressure is applied to the reduction furnace through the dry buffer tank 100 to absorb harmful gases and other substances such as silicon powder. A muffler 422 is installed on the vacuum pump outlet pipe 420 of the Roots vacuum pump 400 to reduce the noise generated when the pump is in operation.

[0043] like Figure 1As shown in , the dry buffer tank 100 is arranged between the Roots vacuum pump 400 and the reduction furnace, and is used to process materials such as silicon powder that may cause damage to the vacuum pump, prevent silicon powder from directly entering the vacuum pump, thereby protecting the Roots vacuum pump 400 from wear or blockage, and also avoiding the pollution of the vacuum pump oil by silicon powder. The dry buffer tank 100 is mainly composed of a tank body 110 and a collection bucket 120 at the bottom of the tank body 110. Among them, the upper part of the tank body 110 is roughly cylindrical, and the bottom is truncated. In addition, a buffer tank inlet pipe 130 and a buffer tank outlet pipe 140 are arranged on the outer side of the upper side wall of the tank body 110. The buffer tank inlet pipe 130 is connected to the inside of the reduction furnace for exhaust; the buffer tank outlet pipe 140 is connected to the vacuum pump inlet pipe 410 for providing negative pressure. In addition, a dry filter 114 is arranged in the tank body 110 to filter out solid substances such as silicon powder to prevent them from entering the Roots vacuum pump 400. Meanwhile, the collecting barrel 120 is disposed at the bottom of the tank body 110 and communicated with the bottom of the tank body 110 , and is used to collect solid substances such as silicon powder filtered out by the dry filter 114 for recycling.

[0044] In this embodiment, the safety system is an explosion-proof system for preventing flash explosion failure of the dry buffer tank 100, and is used to improve the safety and stability of the entire equipment. The safety system mainly includes a nitrogen delivery pipeline 300, a sensor module 200, and a DCS module 500.

[0045] like Figure 1 As shown in , one end of the nitrogen delivery pipeline 300 is arranged at the end of the buffer tank inlet pipe 130 of the dry buffer tank 100, and the other end is connected to the nitrogen input source, which is used to pass nitrogen into the dry buffer tank 100 for protection. The protection principle is: the introduction of nitrogen can dilute the oxygen concentration in the air, reduce the possibility of contact between combustible substances and oxygen, and can also replace the flammable gas that may exist with nitrogen, thereby reducing the risk of explosion and preventing the flammable and explosive gases, powders and other substances in the dry buffer tank 100 from reaching the explosion limit and causing flash explosion. At the same time, a nitrogen flowmeter 310 and a nitrogen flow regulating valve 320 are provided on the nitrogen delivery pipeline 300. Among them, the nitrogen flowmeter 310 is used to monitor the nitrogen flow in the nitrogen delivery pipeline 300 in real time, is connected to the DCS module 500 signal, and transmits the nitrogen flow signal to the DCS module 500 in real time for feedback. The nitrogen flow regulating valve 320 is equipped with an electric actuator, which is also connected to the DCS module 500 by signal, and is controlled by the DCS module 500 to change its opening size, thereby adjusting the nitrogen flow in the nitrogen delivery pipeline 300.

[0046] like Figure 1As shown in , the sensor module 200 is arranged inside the tank body 110 of the dry buffer tank 100, and is used to obtain parameter information related to the risk of flashover, such as the temperature and pressure inside the dry buffer tank 100. In this embodiment, the sensor module 200 mainly includes a temperature sensor 210 and a pressure sensor 220, both of which are arranged inside the tank body 110 of the dry buffer tank 100. The temperature sensor 210 and the pressure sensor 220 are both connected to the DCS module 500 by signal, and transmit real-time signals of the pressure and temperature inside the dry buffer tank 100 to the DCS module 500, which are used to judge the situation inside the dry buffer tank 100 at this time, so as to facilitate the adjustment of the nitrogen flow in the nitrogen delivery pipeline 300 according to the situation.

[0047] like Figure 1 As shown in FIG. 5 , the DCS module 500 is signal-connected to the nitrogen flow meter 310, the nitrogen flow regulating valve 320, the temperature sensor 210 and the pressure sensor 220. In this embodiment, the DCS module 500 is a distributed control system based on a computer program, which can perform centralized management and decentralized control. Specifically, the DCS module 500 generates a dynamic nitrogen flow threshold in real time according to the signals of the temperature sensor 210 and the pressure sensor 220. The dynamic nitrogen flow threshold is determined under experimental conditions, and can maintain a change curve of nitrogen flow values ​​that can prevent flash explosion of an estimated amount of flammable gas, silicon powder and other flammable and explosive substances under certain temperature and pressure conditions. When the real-time flow value fed back by the nitrogen flow meter 310 signal is less than the dynamic nitrogen flow threshold, the DCS module 500 controls the nitrogen flow regulating valve 320 to increase its opening; when the real-time flow value fed back by the nitrogen flow meter 310 signal is greater than the dynamic nitrogen flow threshold, the DCS module 500 controls the nitrogen flow regulating valve 320 to reduce its opening, thereby achieving dynamic balance and ensuring that a suitable nitrogen flow is always maintained in the nitrogen delivery pipeline 300.

[0048] A specific implementation of this embodiment is:

[0049] When the reduction dry vacuum equipment of this embodiment is used to clean the chassis after the reduction furnace is dismantled, first, the inside of the reduction furnace, the dry buffer tank 100 and the Roots vacuum pump 400 are connected in sequence; then, the Roots vacuum pump 400 and the DCS module 500 in the safety system are started, and the nitrogen source of the nitrogen delivery pipeline 300 is opened; after the reduction dry vacuum equipment is started as a whole, the dry buffer tank 100 will inhale flammable and explosive gases, powders and other substances during the cleaning process, and its internal temperature and pressure will also change in this process; at this time, the sensor module 200 monitors the internal temperature and pressure of the dry buffer tank 100 in real time, and the DCS module 500 generates a dynamic nitrogen flow threshold in real time according to the feedback temperature and pressure signals, and compares the dynamic nitrogen flow threshold with the real-time flow value fed back by the nitrogen flow meter 310 signal, and then further controls the dynamic adjustment of the opening of the nitrogen flow regulating valve 320, and the flash explosion risk in the dry buffer tank 100 is controlled by the dynamic change of the opening, so that the operation process of the equipment is safer and more stable.

[0050] In this embodiment, the dry vacuum equipment is restored by setting up a nitrogen delivery pipeline 300, a sensor module 200 and a DCS module 500 in the safety system, and relying on the DCS module 500 to control the nitrogen flow meter 310, the nitrogen flow control valve 320, the temperature sensor 210 and the pressure sensor 220 to form a dynamic adjustment system for the nitrogen flow rate, thereby reducing the risk of flash explosion, improving the safety and stability of the equipment, and solving the problem in the prior art that dry vacuum equipment is difficult to monitor and prevent flash explosions of flammable and explosive substances.

[0051] At the same time, in this embodiment, a DCS module 500 is provided to control the nitrogen flow meter 310, the nitrogen flow control valve 320, the temperature sensor 210 and the pressure sensor 220 to form a dynamic regulation system for nitrogen flow, thereby achieving full utilization of nitrogen and resource conservation.

[0052] Preferably, in this embodiment, the safety system is also equipped with an explosion relief vent 600. Figure 1As shown in , the explosion vent 600 is provided on the upper side wall of the tank body 110 of the dry buffer tank 100, and is used to quickly release the pressure when the internal pressure of the dry buffer tank 100 exceeds the safety threshold, so as to prevent the equipment from rupturing or exploding. The explosion vent 600 can adopt an automatic reset explosion vent, which automatically closes after the pressure is reduced and resumes normal working state. In addition, the explosion vent 600 can also be provided with a bursting disc 610. When the internal pressure of the dry buffer tank 100 exceeds the preset bursting pressure of the bursting disc, the bursting disc 610 will rupture and release the pressure. The advantage of the bursting disc 610 is that the bursting pressure can be accurately set to ensure release at a specific pressure; and it can respond quickly, and rupture quickly when the pressure exceeds the preset value, and quickly release the pressure; at the same time, it also has a diaphragm to prevent the leakage of the medium, so as to prevent the leakage of harmful gases in the dry buffer tank 100. However, the bursting disc 610 is limited to one-time use. If flash explosions and other situations where the pressure exceeds the preset value occur frequently, it is inconvenient to replace it frequently. However, for the equipment of this embodiment, since the safety system ensures that the risk of flash explosion is low, the inconvenience caused by frequent replacement of the bursting disc 610 can be reduced. The bursting disc 610 serves as the second protection method of the safety system, thereby improving the effectiveness of the safety system.

[0053] In one or more embodiments, the safety system of the above-described embodiment can be applied to other sealed containers with inlet pipes and outlet pipes other than the dry buffer tank 100, and real-time dynamic protection of gas can also be performed to reduce the risk of flash explosion of flammable and explosive substances stored and transported therein.

[0054] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A security system, characterized in that: Include: A nitrogen delivery pipeline (300) is arranged on the inlet pipe of the closed container, and a nitrogen flow meter (310) and a nitrogen flow regulating valve (320) are arranged on the nitrogen delivery pipeline (300); A sensor module (200) comprising at least a temperature sensor (210) and a pressure sensor (220), both of which are arranged inside the sealed container; and A DCS module (500) is signal-connected to the nitrogen flow meter (310), the nitrogen flow regulating valve (320), the temperature sensor (210), and the pressure sensor (220); The DCS module (500) generates a dynamic nitrogen flow threshold in real time according to the temperature sensor (210) and the pressure sensor (220) signals; when the real-time flow value fed back by the nitrogen flow meter (310) signal is less than the dynamic nitrogen flow threshold, the DCS module (500) controls the nitrogen flow regulating valve (320) to increase the opening, and vice versa to decrease the opening.

2. The security system according to claim 1, characterized in that Also includes: The explosion vent (600) is arranged on the side wall of the sealed container.

3. The security system according to claim 2, characterized in that A bursting piece (610) is arranged in the explosion vent (600).

4. The security system according to claim 3, characterized in that The bursting disc (610) has a diaphragm for preventing the medium from leaking out.

5. The security system according to claim 1, characterized in that: The sealed container is a dry buffer tank (100).

6. A reduction dry vacuum equipment, characterized in that: Include: The safety system according to claim 5, wherein the buffer tank inlet pipe (130) of the dry buffer tank (100) is connected to the interior of the silicon reduction furnace; and A Roots vacuum pump (400) is in communication with a buffer tank outlet pipe (140) of the dry buffer tank (100).

7. The reduction dry vacuum equipment according to claim 6, characterized in that: A dry filter (114) is arranged in the dry buffer tank (100).

8. The reduction dry vacuum equipment according to claim 7, characterized in that: The dry buffer tank (100) at least comprises: a tank (110) in which the dry filter (114) is disposed; and A collection bucket (120) is disposed at the bottom of the tank body (110) and is in communication therewith.

9. The reduction dry vacuum equipment according to claim 6, characterized in that: A muffler (422) is provided on the vacuum pump outlet pipe (420) of the Roots vacuum pump (400).

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