Cleaning system and method for red phosphorus vacuum pump of single crystal furnace

Abstract

The single crystal furnace red phosphorus vacuum pump cleaning system comprises a vacuum pump body, a water tank, a water feeding pump and a control device, a drainage hole located below the axis of a pump shell and located at the lowest point of the arc-shaped wall of the pump shell is formed in the pump shell of the vacuum pump body, the drainage hole is formed in the radial direction of the pump shell, a water inlet hole located above the drainage hole is formed in the pump shell, the inlet end of the water feeding pump communicates with the water tank through a pipeline, and the outlet end of the water feeding pump communicates with the water inlet hole through a pipeline. A water return opening is formed in the water tank and communicates with the drainage hole through a pipeline, and the control device is electrically connected with the water feeding pump through a wire. By means of the innovative design thought, a certain number of holes are formed in the pump shell, external pure water is fed into the pump cavity through the water pipe to flush oxide on the rotor, it is avoided that the oxide is deposited in the pump shell, and the pump shell is corroded, so that the running time of the pump is prolonged, and the failure rate is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of single crystal silicon production, and in particular to a single crystal furnace red phosphorus vacuum pump cleaning system and method. Background Art

[0002] The two main vacuum pumps currently used in the industry are screw pumps and water ring pumps. Screw pumps offer advantages in terms of energy efficiency and vacuum performance. However, screw pumps run at high temperatures, and due to the accumulation of oxides on the rotor or cavity, they are prone to spontaneous combustion, resulting in severe economic losses. Therefore, they are not suitable for red phosphorus drawing. Summary of the Invention

[0003] In order to solve the technical problems existing in the above technology, it is necessary to provide a single crystal furnace red phosphorus vacuum pump cleaning system.

[0004] A single crystal furnace red phosphorus vacuum pump cleaning system includes a vacuum pump body, a water tank, a water supply pump, and a control device; the pump housing of the vacuum pump body is provided with a drainage hole located below the axis of the pump housing and at the lowest point of the curved wall of the pump housing, the drainage hole is arranged along the radial direction of the pump housing, the pump housing is provided with a water inlet hole located above the drainage hole, the inlet end of the water supply pump is connected to the water tank through a pipe, the outlet end of the water supply pump is connected to the water inlet hole through a pipe, the water tank is provided with a return water port, the return water port is connected to the drainage hole through a pipe, and the control device is electrically connected to the water supply pump through a wire.

[0005] Preferably, the axis of the water inlet hole and the axis of the drain hole form an angle of 10-20°.

[0006] Preferably, the axis of the water inlet hole and the axis of the drain hole form an angle of 15°.

[0007] Preferably, the water inlet holes are arranged symmetrically along the axis of the drainage hole.

[0008] Preferably, a pH sensor for obtaining pH value data of the cleaning water in the water tank is installed in the water tank, and the pH sensor is electrically connected to the control device through a wire.

[0009] Preferably, a water flow sensor for measuring the flow rate of the cleaning water is installed on the pipe of the water inlet, and the water flow sensor is electrically connected to the control device through a wire.

[0010] Preferably, a pressure sensor for measuring the pressure of the cleaning water is installed on the pipe of the water inlet, and the pressure sensor is electrically connected to the control device through a wire.

[0011] It is also necessary to provide a method for cleaning the red phosphorus vacuum pump of a single crystal furnace.

[0012] A single crystal furnace red phosphorus vacuum pump cleaning method, using the single crystal furnace red phosphorus vacuum pump cleaning system described above for cleaning, comprising the following steps, Step S1: after the pulled crystal bar is completely taken out from the single crystal furnace, stay for 5-10 min, and get the cleaning water PH value data in the water tank, and set the fluctuation range A of the cleaning water PH value data as -0.5-0; Step S2: the control device starts the water supply pump, and the cleaning water in the water tank is sprayed into the pump shell through the water inlet hole, and the rotor surface is washed according to the preset washing time; Step S3: after reaching the preset washing time, the water supply pump is stopped, and it is judged whether the cleaning water PH value data in the water tank is within the fluctuation range A; Step S4: if the cleaning water PH value data in the water tank exceeds the fluctuation range A, the water supply pump is started, and the rotor needs to be washed for 2-3 min again, if the monitoring cleaning water PH value data in the water tank does not change within a period of time, the water supply pump is stopped, if the cleaning water PH value data changes, step S4 is continued until the cleaning water PH value data in the water tank does not change within a period of time; Step S5: if the cleaning water PH value data in the water tank does not exceed the fluctuation range A, return to step S2 for continuous washing; Step S6: after the water supply pump is stopped after the washing is completed, and there is no cleaning water flowing out of the pipeline connected with the drain hole, the whole system is closed and stopped.

[0013] Preferably, in step S2, the specific cleaning process includes three stages, Initial cleaning stage: the cleaning time is 25% of the total cleaning time, and the flow rate of the cleaning water and the water pressure of the cleaning water increase in steps with the increase of the cleaning time; Mid-term cleaning stage: the cleaning time is 50% of the total cleaning time, and the flow rate of the cleaning water and the water pressure of the cleaning water are maintained at the standard normal cleaning water to continuously wash the rotor; Late cleaning stage: the cleaning time is 25% of the total cleaning time, and the flow rate of the cleaning water and the water pressure of the cleaning water decrease in steps with the increase of the cleaning time.

[0014] Preferably, in step S2, the preset cleaning time corresponds to the size of the crystal bar, that is, the larger the size of the crystal bar, the longer the cleaning time.

[0015] Compared with the prior art, the present invention provides a single crystal furnace red phosphorus vacuum pump cleaning system and method, including a vacuum pump body, a water tank, a water supply pump, and a control device; the pump housing of the vacuum pump body is provided with a drainage hole located below the axis of the pump housing and at the lowest point of the arc-shaped wall of the pump housing, the drainage hole is arranged along the radial direction of the pump housing, the pump housing is provided with a water inlet located above the drainage hole, the inlet end of the water supply pump is connected to the water tank through a pipe, the outlet end of the water supply pump is connected to the water inlet through a pipe, a return water port is provided on the water tank, the return water port is connected to the drainage hole through a pipe, and the control device is electrically connected to the water supply pump through a wire. Through an innovative design concept, the present invention opens a certain number of holes in the pump housing to send external pure water into the pump cavity through a water pipe to flush the oxides on the rotor, so as to prevent the oxides from being deposited in the pump housing and causing corrosion of the pump housing, thereby improving the operation time of the pump and reducing the failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is a schematic diagram of the positions of the drain hole and the water inlet hole on the pump casing of the present invention.

[0018] Figure 2 This is a schematic diagram of the single crystal furnace red phosphorus vacuum pump cleaning system of the present invention.

[0019] Figure 3 This is a schematic diagram of the present invention before cleaning the red phosphorus vacuum pump rotor.

[0020] Figure 4 This is a schematic diagram of the red phosphorus vacuum pump rotor after cleaning according to the present invention.

[0021] In the figure: vacuum pump body 01, water tank 02, water supply pump 03, control device 04, pump housing 05, water inlet hole 51, and drain hole 52. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner", "lower" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0024] Please see Figure 1 、 Figure 2 In one embodiment, the present invention provides a single crystal furnace red phosphorus vacuum pump cleaning system, including a vacuum pump body 01, a water tank 02, a water supply pump 03, and a control device 04; a pump casing 05 of the vacuum pump body 01 is provided with a drainage hole 52 located below the axis of the pump casing 05 and at the lowest point of the arc-shaped wall of the pump casing 05, and the drainage hole 52 is arranged along the radial direction of the pump casing 05. A water inlet 51 located above the drainage hole 52 is provided on the pump casing 05, and the inlet end of the water supply pump 03 is connected to the water tank 02 through a pipe, and the outlet end of the water supply pump 03 is connected to the water inlet 51 through a pipe. A return water port is provided on the water tank 02, and the return water port is connected to the drainage hole 52 through a pipe. The control device 04 is electrically connected to the water supply pump 03 through a wire; the control device 04 can adopt a PLC control cabinet.

[0025] The drainage holes 52 and the water inlet holes 51 are evenly distributed on the outer wall of the pump housing 05 along the axis of the pump housing 05. The number of holes can be determined according to actual needs. For example, the number of drainage holes 52 and water inlet holes 51 can be two.

[0026] In one embodiment, the axis of the water inlet hole 51 and the axis of the drain hole 52 form an angle of 10-20°.

[0027] As a preferred option, the axis of the water inlet 51 forms a 15° angle with the axis of the drain hole 52, tilting the outlet end of the water inlet 51 upward. When cleaning water is sprayed into the pump housing 05 through the water inlet 51, the 15° tilt of the water inlet 51 allows the cleaning water to be sprayed symmetrically from bottom to top, centered around the drain hole 52, toward the rotor in the pump housing 05. During cleaning, the rotor can be rotated at a low, constant speed by the vacuum pump's variable-frequency motor, or manually by turning the rotor. Of course, the rotor can also be rotated in reverse. When the rotor rotates forward, the direction of the cleaning water spraying on one side will be opposite to the rotation direction of the rotor, which can create more impact force between the rotor and the sprayed cleaning water, and improve the cleaning effect; while the direction of the cleaning water spraying on the other side will be the same as the rotation direction of the rotor, which can flush the dirt under the action of a certain impact force; of course, when the rotor rotates reversely, the direction of the cleaning water spraying on both sides will be opposite to that when the rotor rotates forward. Through the forward and reverse rotation of the rotor, combined with the impact force of the cleaning water, the cleaning effect of the rotor can be improved.

[0028] In more detail, the water inlet holes 51 are arranged symmetrically along the axis of the drainage hole 52 .

[0029] In one embodiment, a pH sensor for obtaining pH value data of the cleaning water in the water tank 02 is installed in the water tank 02 , and the pH sensor is electrically connected to the control device 04 via a wire.

[0030] In one embodiment, a water flow sensor for measuring the flow rate of the cleaning water is installed on the pipe of the water inlet 51, and the water flow sensor is electrically connected to the control device 04 through a wire.

[0031] In one embodiment, a pressure sensor for measuring the pressure of the cleaning water is installed on the pipe of the water inlet 51 , and the pressure sensor is electrically connected to the control device 04 via a wire.

[0032] In one embodiment, in order to better illustrate the technical solution presented by the present invention, the cleaning of the red phosphorus vacuum pump after pulling a 6-inch crystal rod in a single crystal furnace is taken as an example. The specific cleaning steps are as follows: Step (1): After the pulled crystal rod is completely taken out of the single crystal furnace, it stays for 5 to 10 minutes. The pH sensor will obtain the pH value of the cleaning water in the water tank. In the initial state, the water tank stores pure water with a pH value of 7. The initial pH value will be stored in the control device. At the same time, the control device will pre-set the fluctuation range of the pH value of the cleaning water to A, and the fluctuation range of A is -0.5 to 0; Step (2): After the above preparations are completed, the control device issues a command and starts the water supply pump, spraying the cleaning water in the water tank into the pump housing through the water inlet hole, and flushing the rotor surface for 25 minutes (750 seconds) according to the preset flushing time; Step (3): After the preset flushing time is reached, the control device issues a command and stops the water pump. The pH sensor obtains the pH value of the cleaning water in the water tank to determine whether the pH value data of the cleaning water in the water tank at this time is within the fluctuation range A; Step (4): If the pH value data of the cleaning water in the water tank exceeds the fluctuation range A, the control device issues an instruction and starts the water supply pump, and the rotor needs to be flushed for another 2-3 minutes (120-180 seconds). If the pH value data of the cleaning water in the water tank does not change within a period of time, for example, when the pH value data of the cleaning water monitored in the water tank remains unchanged for more than 1 minute (60 seconds), the control device issues an instruction and stops the water supply pump; if the pH value data of the cleaning water in the water tank changes, step (4) is continued until the pH value data of the cleaning water in the water tank does not change within a period of time (remains unchanged for more than 1 minute); Step (5): If the PH value of the cleaning water in the water tank is not beyond the fluctuation range A, it is necessary to return to step (2) to continue the flushing. Step (6): After the flushing is completed, the control device issues an instruction and stops the water pump, and when there is no cleaning water flowing out of the pipeline connected with the drain hole, the whole system is closed and stopped.

[0033] In detail, in step (2), the specific cleaning process has three stages, which are the initial cleaning stage, the middle cleaning stage and the late cleaning stage. In the initial cleaning stage: in this stage, the cleaning time is 25% of the total cleaning time, that is, the flushing time in this stage is 375 seconds, and the flow rate of the cleaning water and the water pressure of the cleaning water are increased in a stepped manner with the gradual increase of the cleaning time; for example, we can gradually increase the flow rate of the cleaning water and the water pressure of the cleaning water by 0.5 every 75 seconds, and the specific data are shown in Table 1. Table 1:

[0034] In the middle cleaning stage: the cleaning time is 50% of the total cleaning time, that is, the flushing time in this stage is 750 seconds, and the flow rate of the cleaning water and the water pressure of the cleaning water are maintained at the standard normal cleaning water to continuously flush the rotor, and the specific data are shown in Table 2; the flushing time is continued from the 375th second. Table 2:

[0035] In the late cleaning stage: the cleaning time is 25% of the total cleaning time, that is, the flushing time in this stage is 375 seconds, and the flow rate of the cleaning water and the water pressure of the cleaning water are decreased in a stepped manner with the increase of the cleaning time, for example, the flow rate of the cleaning water is decreased by 0.25 and the water pressure of the cleaning water is decreased by 0.5 every 75 seconds, and the specific data are shown in Table 3, and the flushing time is continued from the 1125th second.

[0036] Table 3:

[0037] Of course, the flow rate and the water pressure in the above Tables 1, 2 and 3 are examples under a certain working condition in the actual use process, and the specific data can be adjusted according to the attachment of dirt and the cleaning needs.

[0038] To explain in detail, during the mid-term cleaning stage, the rotor first rotates forward for 375 seconds for cleaning, that is, from 375 seconds to 750 seconds, the rotor is in the forward cleaning state; then it rotates reversely for 375 seconds for cleaning, that is, from 750 seconds to 1125 seconds, the rotor is in the reverse cleaning state; maintain the standard normal cleaning water flow rate and cleaning water pressure to continuously flush the rotor.

[0039] Of course, the preset cleaning time is proportional to the size of the ingot, meaning that the larger the ingot, the longer the cleaning time. For example, when pulling an 8-inch ingot, the corresponding cleaning time is 35 minutes (2100 seconds); when pulling a 12-inch ingot, the corresponding cleaning time is 45 minutes (2700 seconds). The cleaning method used for pulling these two ingots is the same as that for pulling a 6-inch ingot, with only the time difference.

[0040] Please see Figure 3 Before cleaning the rotor, there is obvious dark dirt attached to the rotor surface; Figure 4 It can be seen that after cleaning using the method of the present invention, the dirt on the surface of the rotor is obviously removed, indicating that the expected cleaning effect has been achieved.

[0041] The above disclosure is only a preferred embodiment of the present invention, and it is certainly not intended to limit the scope of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A single crystal furnace red phosphorus vacuum pump cleaning system, characterized by: It includes a vacuum pump body, a water tank, a water supply pump, and a control device; the pump casing of the vacuum pump body is provided with a drainage hole located below the axis of the pump casing and at the lowest point of the arc-shaped wall of the pump casing, and the drainage hole is arranged along the radial direction of the pump casing; the pump casing is provided with a water inlet located above the drainage hole; the inlet end of the water supply pump is connected to the water tank through a pipe, and the outlet end of the water supply pump is connected to the water inlet through a pipe; a return water port is provided on the water tank, and the return water port is connected to the drainage hole through a pipe; the control device is electrically connected to the water supply pump through a wire.

2. The single crystal furnace red phosphorus vacuum pump cleaning system according to claim 1, characterized in that: The axis of the water inlet hole and the axis of the drain hole form an angle of 10-20 degrees.

3. The single crystal furnace red phosphorus vacuum pump cleaning system according to claim 2, characterized in that: The axis of the water inlet hole and the axis of the drain hole form an angle of 15°.

4. The single crystal furnace red phosphorus vacuum pump cleaning system according to claim 3, characterized in that: The water inlet holes are arranged symmetrically along the axis of the drainage hole.

5. The single crystal furnace red phosphorus vacuum pump cleaning system according to claim 1, characterized in that: A pH sensor for obtaining pH value data of the cleaning water in the water tank is installed in the water tank, and the pH sensor is electrically connected to the control device through a wire.

6. The single crystal furnace red phosphorus vacuum pump cleaning system according to claim 1, characterized in that: A water flow sensor for measuring the flow rate of the cleaning water is installed on the pipe of the water inlet hole, and the water flow sensor is electrically connected to the control device through a wire.

7. The single crystal furnace red phosphorus vacuum pump cleaning system according to claim 1, characterized in that: A pressure sensor for measuring the pressure of the cleaning water is installed on the pipe of the water inlet hole, and the pressure sensor is electrically connected to the control device through a wire.

8. A method for cleaning a red phosphorus vacuum pump of a single crystal furnace, using the cleaning system for a red phosphorus vacuum pump of a single crystal furnace according to any one of claims 1 to 7, characterized in that: The following steps are included: Step S1: After the pulled crystal rod is completely taken out of the single crystal furnace, it is left there for 5 to 10 minutes, and the pH value of the cleaning water in the water tank is obtained, and the fluctuation range of the pH value of the cleaning water is set to A between -0.5 and 0; Step S2: The control device starts the water supply pump, sprays the cleaning water in the water tank into the pump housing through the water inlet hole, and rinses the rotor surface according to the preset flushing time; Step S3: After the preset flushing time is reached, the water supply pump is stopped to determine whether the pH value of the flushing water in the water tank is within the fluctuation range A; Step S4: If the pH value of the cleaning water in the water tank exceeds the fluctuation range A, the water supply pump is started and the rotor is flushed for another 2-3 minutes. If the pH value of the cleaning water in the monitoring water tank does not change within a period of time, the water supply pump is stopped. If the pH value of the cleaning water changes, step S4 is continued until the pH value of the cleaning water in the water tank does not change within a period of time. Step S5: If the pH value of the washing water in the water tank does not exceed the fluctuation range A, return to step S2 to continue washing; Step S6: After the flushing is completed, the water pump is shut down. When no more cleaning water flows out of the pipe connected to the drain hole, the entire system is shut down.

9. The method for cleaning a red phosphorus vacuum pump of a single crystal furnace according to claim 8, characterized in that: In step S2, the specific cleaning process includes three stages: Initial cleaning stage: The cleaning time is 25% of the total cleaning time. The flow rate and pressure of the cleaning water increase in a step-by-step manner as the cleaning time increases. Mid-term cleaning stage: The cleaning time is 50% of the total cleaning time. The standard normal cleaning water flow rate and water pressure are maintained to continuously flush the rotor. Late cleaning stage: The cleaning time is 25% of the total cleaning time. The flow rate and water pressure of the cleaning water decrease in a step-by-step manner as the cleaning time increases.

10. The method for cleaning a red phosphorus vacuum pump of a single crystal furnace according to claim 9, characterized in that: In step S2 , the preset cleaning time corresponds to the size of the crystal ingot, that is, the larger the size of the crystal ingot, the longer the cleaning time.

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