Negative pressure adjusting system for melting furnace

Abstract

When the negative pressure adjusting system is used, before the melting furnace is vacuumized, a vacuumizing assembly firstly carries out vacuumizing operation on a negative pressure front-arranged piece to enable the negative pressure front-arranged piece to be in a negative pressure state, then a first switch and a second switch are turned off, the vacuumizing assembly is communicated with the melting furnace, and the negative pressure front-arranged piece is in a negative pressure state. The vacuum-pumping assembly carries out vacuum-pumping operation on the melting furnace, at the moment, a quartz crucible starts to be melted in the melting furnace, when melting reaches a preset degree, the negative pressure adjusting system is switched to a third state from a second state, the negative pressure front-arranged piece is conducted between the melting furnace and the vacuum-pumping assembly, and at the moment, the vacuum-pumping speed is rapidly increased; the negative pressure preposed piece and the vacuumizing assembly perform vacuumizing operation on the melting furnace at the same time, the provided negative pressure is large, and the negative pressure environment is stable. Therefore, the stability of the negative pressure environment in the melting furnace is ensured in the continuous vacuumizing process of the melting furnace.

Description

Technical Field

[0001] The utility model relates to the technical field of quartz crucible manufacturing, in particular to a negative pressure regulating system for a melting furnace. Background Art

[0002] Quartz crucibles are mainly used in the photovoltaic and semiconductor fields and can support continuous crystal pulling under high temperature conditions. In the production process of single crystal silicon wafers, quartz crucibles are key components of photovoltaic single crystal furnaces and consumable vessels for pulling large-diameter single crystal silicon rods. They are mainly used to hold molten silicon and make crystal rods required for subsequent processes.

[0003] The quartz crucible is translucent and is divided into two layers: the outer layer, also called the bubble composite layer (opaque layer with a high bubble content), and the inner layer, also called the bubble depletion layer (vacuum transparent layer without bubbles). The outer layer needs to evenly scatter the heat from the heater, so a specified number and size of bubbles are required to evenly heat the silicon melt; the inner layer is a transparent layer, called a bubble depletion layer, which has higher requirements for high purity, low aluminum, low alkali, and anti-crystallization of high-purity quartz sand. Because the inner wall of the quartz crucible is in direct contact with the silicon melt, if there are bubbles in the transparent layer, the bubbles will continue to grow at a high temperature for a long time during the crystal pulling process until they break through the inner wall of the crucible, and bring out a small amount of quartz debris impurities into the silicon melt, causing the silicon melt to be contaminated and interfering with the growth of silicon single crystals, ultimately resulting in unqualified performance indicators of single crystal silicon or reduced production efficiency.

[0004] The general process of producing quartz crucibles is as follows: high-purity quartz sand is loaded into a rotary molding mold that can be tilted at any angle (a graphite mold is inserted into a metal water-cooling jacket), and the rotating device that has been formed into a crucible shape is rotated back to the electrode rod, and then the electrode is arced and inserted into the formed powder cavity to quickly melt it into a crucible-shaped molten quartz, which is taken out after cooling, and the production of a quartz crucible blank is completed. Therefore, in order to minimize the bubbles in the transparent layer of the quartz crucible, the mold will be evacuated to create a negative pressure environment during melting, and the bubbles in the transparent layer will be pumped to the bubble layer or out of the crucible. The existing technology often uses a vacuum pump to create a negative pressure environment, but the negative pressure provided by the vacuum pump is usually small, and the negative pressure environment is not stable enough.

[0005] Therefore, how to improve the stability of the negative pressure environment is a technical problem that technicians in this field currently need to solve. Utility Model Content

[0006] In view of this, the purpose of the utility model is to provide a negative pressure regulating system for a melting furnace to improve the stability of the negative pressure environment;

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] A negative pressure regulating system for a melting furnace, comprising a vacuum pumping component, a negative pressure pre-positioning component, a first switch, a second switch and a third switch, wherein the first switch is arranged between the vacuum pumping component and the negative pressure pre-positioning component, the second switch is arranged between the negative pressure pre-positioning component and the melting furnace, and the third switch is arranged between the vacuum pumping component and the melting furnace;

[0009] When the negative pressure regulating system is in the first state, the first switch is turned on, the second switch and the third switch are turned off, and the vacuum pumping component performs a vacuum pumping operation on the negative pressure pre-position element;

[0010] When the negative pressure regulating system is in the second state, the third switch is turned on, the first switch and the second switch are turned off, and the vacuum pumping assembly performs a vacuum pumping operation on the melting furnace;

[0011] When the negative pressure regulating system is in the third state, the second switch and the third switch are turned on, the first switch is turned off, and the negative pressure pre-position part and the vacuum pumping assembly simultaneously perform the vacuum pumping operation on the melting furnace.

[0012] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the vacuum assembly includes a first vacuum pump and a second vacuum pump, and the negative pressure pre-piece is provided with a first inlet connected to the first vacuum pump and a second inlet connected to the second vacuum pump.

[0013] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the negative pressure pre-piece is a vacuum negative pressure tank, and the vacuum negative pressure tank is provided with a first outlet and a second outlet connected to the melting furnace.

[0014] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the first switch includes a first energy storage valve and a second energy storage valve, the first energy storage valve is arranged between the first inlet and the first vacuum pump, and the second energy storage valve is arranged between the second inlet and the second vacuum pump;

[0015] And / or, the second switch includes a first connecting valve and a second connecting valve, the first connecting valve is arranged between the first outlet and the melting furnace, and the second connecting valve is arranged between the second outlet and the melting furnace;

[0016] And / or, the third switch includes a first vacuum valve and a second vacuum valve, the first vacuum valve is arranged between the first vacuum pump and the melting furnace, and the second vacuum valve is arranged between the second vacuum pump and the melting furnace.

[0017] Optionally, in the above-mentioned negative pressure regulating system for the melting furnace, the negative pressure regulating system for the melting furnace also includes a first three-way valve and a filter tank, the first end of the first three-way valve is connected to the third switch, the second end of the first three-way valve is connected to the second switch, the third end of the first three-way valve is connected to the filter tank, and the filter tank is arranged between the first three-way valve and the melting furnace.

[0018] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the third switch further includes a third vacuum valve, and the third vacuum valve is arranged between the filter tank and the melting furnace.

[0019] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the negative pressure regulating system for a melting furnace further comprises an exhaust valve, which is arranged between the melting furnace and the filter tank and is used to exhaust gas;

[0020] And / or, the negative pressure regulating system for the melting furnace further comprises a vacuum transmitter, which is arranged between the melting furnace and the filter tank and is used to monitor the pressure.

[0021] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the negative pressure regulating system for a melting furnace further comprises a vacuum pressure gauge, which is connected to the negative pressure pre-piece and is used to monitor the pressure of the negative pressure pre-piece.

[0022] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the negative pressure regulating system for a melting furnace further comprises a pressure alarm, and the pressure alarm is electrically connected to the vacuum pressure gauge for issuing a pressure warning.

[0023] Optionally, in the above-mentioned negative pressure regulating system for a melting furnace, the number of the melting furnaces is one or more, and when the number of the melting furnaces is two or more, the two or more melting furnaces are arranged in parallel.

[0024] The negative pressure regulating system for a melting furnace provided by the utility model, when in use, before vacuuming the melting furnace, the vacuuming component first performs a vacuuming operation on the negative pressure pre-position part, so that the negative pressure pre-position part is in a negative pressure state, and then the first switch and the second switch are closed, the vacuuming component is connected to the melting furnace, and the vacuuming component performs a vacuuming operation on the melting furnace. At this time, the quartz crucible begins to be melted in the melting furnace. When the melting reaches a preset degree, the negative pressure regulating system switches from the second state to the third state, and the negative pressure pre-position part is connected between the melting furnace and the vacuuming component. At this time, the pumping speed is rapidly increased, and the negative pressure pre-position part and the vacuuming component simultaneously perform a vacuuming operation on the melting furnace, providing a large negative pressure and a stable negative pressure environment. Therefore, the above process ensures the stability of the internal negative pressure environment of the melting furnace during the continuous vacuuming of the melting furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the utility model 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 utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a schematic diagram of the structure of vacuumizing a melting furnace in the prior art;

[0027] Figure 2 A structural diagram of an embodiment of a negative pressure regulating system disclosed in an embodiment of the utility model;

[0028] Figure 3 A structural diagram of another embodiment of the negative pressure regulating system disclosed in the embodiment of the utility model;

[0029] Figure 4 A structural diagram of another embodiment of the negative pressure regulating system disclosed in the embodiment of the utility model;

[0030] Figure 5 Disclosed by the embodiments of the present utility model;

[0031] Figure 6 It is a schematic diagram of the structure of the vacuum negative pressure tank disclosed in the embodiment of the utility model;

[0032] in:

[0033] Melting furnace 100;

[0034] A first vacuum pump 200, a second vacuum pump 201;

[0035] Vacuum negative pressure tank 300, first inlet 301, second inlet 302, first outlet 303, second outlet 304;

[0036] A first switch 400, a first energy storage valve 401, and a second energy storage valve 402;

[0037] A second switch 500, a first connecting valve 501, a second connecting valve 502, and a third connecting valve 503;

[0038] A third switch 600, a first vacuum valve 601, a second vacuum valve 602, and a third vacuum valve 603;

[0039] Filter tank 700, first three-way valve 701, second three-way valve 702;

[0040] Exhaust valve 800, vacuum transmitter 900. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making novel work are within the scope of protection of the utility model.

[0042] In the description of the present invention, it should be understood that the terms "upper", "lower", "top surface", "bottom surface" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the positions or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] like Figure 1 As shown, it is a simplified schematic diagram of vacuuming a melting furnace in the prior art.

[0044] like Figure 2-Figure 6 As shown, the negative pressure regulating system for a melting furnace disclosed in the utility model comprises a vacuum assembly, a negative pressure pre-assembly, a first switch 400, a second switch 500 and a third switch 600. The first switch 400 is arranged between the vacuum assembly and the negative pressure pre-assembly, the second switch 500 is arranged between the negative pressure pre-assembly and the melting furnace 100, and the third switch 600 is arranged between the vacuum assembly and the melting furnace 100. When the negative pressure regulating system is in a first state, the first switch 400 is turned on, and the second switch 500 is turned off. 0 and the third switch 600 are closed, the vacuuming component performs the vacuuming operation on the negative pressure pre-position part, when the negative pressure regulating system is in the second state, the third switch 600 is turned on, the first switch 400 and the second switch 500 are closed, the vacuuming component performs the vacuuming operation on the melting furnace 100, when the negative pressure regulating system is in the third state, the second switch 500 and the third switch 600 are turned on, the first switch 400 is closed, and the negative pressure pre-position part and the vacuuming component simultaneously perform the vacuuming operation on the melting furnace 100. Specifically, the application principle of the utility model is to first use the vacuuming component to vacuum the negative pressure pre-position part so that the negative pressure pre-position part is in a negative pressure state, and then connect the melting furnace 100, the negative pressure pre-position part and the vacuuming component, the negative pressure pre-position part will instantly increase the vacuuming power, and the negative pressure pre-position part cooperates with the vacuuming component to quickly increase the pumping speed, so that the microbubbles in the transparent layer of the quartz crucible are quickly extracted.

[0045] The negative pressure regulating system for the melting furnace 100 provided by the utility model, when in use, before vacuuming the melting furnace 100, the vacuuming component first performs a vacuuming operation on the negative pressure pre-position part, so that the negative pressure pre-position part is in a negative pressure state, and then the first switch 400 and the second switch 500 are closed, the vacuuming component is connected to the melting furnace 100, and the vacuuming component performs a vacuuming operation on the melting furnace 100. At this time, the melting furnace 100 starts to melt the quartz crucible. When the melting reaches a preset degree, the negative pressure regulating system switches from the second state to the third state, and the negative pressure pre-position part is connected between the melting furnace 100 and the vacuuming component. At this time, the pumping speed is rapidly increased, and the negative pressure pre-position part and the vacuuming component simultaneously perform a vacuuming operation on the melting furnace 100, providing a large negative pressure and a stable negative pressure environment. Therefore, the above process ensures the stability of the internal negative pressure environment of the melting furnace 100 during the continuous vacuuming of the melting furnace 100.

[0046] In order to optimize the above technical solution, the vacuum pump assembly includes a first vacuum pump 200 and a second vacuum pump 201, and the negative pressure pre-position piece is provided with a first inlet 301 connected to the first vacuum pump 200 and a second inlet 302 connected to the second vacuum pump 201. Specifically, the number of vacuum pumps is positively correlated with the intensity of vacuuming during the actual production process. The preferred number of vacuum pumps in the utility model is two. When in use, when the negative pressure regulating system is in the first state, the first vacuum pump 200 and the second vacuum pump 201 simultaneously perform vacuuming operations on the negative pressure pre-position piece to quickly put it in a negative pressure state, thereby improving the vacuuming efficiency of the negative pressure pre-position piece. When the negative pressure regulating system is in the third state, the negative pressure pre-position piece, the first vacuum pump 200 and the second vacuum pump 201 simultaneously perform vacuuming operations on the melting furnace 100 to quickly extract the microbubbles in the transparent layer. It should be noted that during melting, long-term operation of the vacuum pump will cause the oil performance to deteriorate, thereby affecting the working effect of the vacuum pump and causing the negative pressure it provides to decrease or become unstable. Therefore, by setting up the first vacuum pump 200 and the second vacuum pump 201, basic negative pressure can be provided, and by arranging the negative pressure pre-component, the stability of the negative pressure environment can be further improved.

[0047] In order to optimize the above technical solution, the negative pressure pre-installed component is a vacuum negative pressure tank 300, and the vacuum negative pressure tank 300 is provided with a first outlet 303 and a second outlet 304 connected to the melting furnace 100. Specifically, the first inlet 301, the second inlet 302, the first outlet 303 and the second outlet 304 of the vacuum negative pressure tank 300 are directly arranged on the side wall of the vacuum negative pressure tank 300, and the interior of the vacuum negative pressure tank 300 is a cavity structure to improve the efficiency of vacuuming. Furthermore, the number of outlets of the vacuum negative pressure tank 300 can be adjusted as long as the internal gas of the melting furnace 100 can be extracted.

[0048] In order to optimize the above technical solution, the first switch 400 includes a first energy storage valve 401 and a second energy storage valve 402, the first energy storage valve 401 is arranged between the first inlet 301 and the first vacuum pump 200, and the second energy storage valve 402 is arranged between the second inlet 302 and the second vacuum pump 201; and / or, the second switch 500 includes a first connecting valve 501 and a second connecting valve 502, the first connecting valve 501 is arranged between the first outlet 303 and the melting furnace 100, and the second connecting valve 502 is arranged between the second outlet 304 and the melting furnace 100; and / or, the third switch 600 includes a first vacuum valve 601 and a second vacuum valve 602, the first vacuum valve 601 is arranged between the first vacuum pump 200 and the melting furnace 100, and the second vacuum valve 602 is arranged between the second vacuum pump 201 and the melting furnace 100. Specifically, when the negative pressure of the vacuum negative pressure tank 300 is too large, the first energy storage valve 401 and / or the second energy storage valve 402 will automatically open to release the excessive negative pressure, thereby protecting the entire negative pressure regulation system from damage and improving the safety of the negative pressure regulation system. When in use, when the negative pressure regulation system is in the first state, the first vacuum valve 601, the second vacuum valve 602, the first connecting valve 501 and the second connecting valve 502 are closed, and the first energy storage valve 401 and the second energy storage valve 402 are opened. The first vacuum pump 200 and the second vacuum pump 201 continuously provide negative pressure conditions to the vacuum negative pressure tank 300. When the pressure of the vacuum negative pressure tank 300 reaches the preset value, the melting of the quartz crucible begins.

[0049] In order to optimize the above technical solution, the negative pressure regulating system for the melting furnace 100 further includes a first three-way valve 701 and a filter tank 700, wherein the first end of the first three-way valve 701 is connected to the third switch 600, the second end of the first three-way valve 701 is connected to the second switch 500, the third end of the first three-way valve 701 is connected to the filter tank 700, and the filter tank 700 is arranged between the first three-way valve 701 and the melting furnace 100. Specifically, the number of filter tanks 700 is consistent with the number of vacuum pumps, which are used to prevent the quartz sand in the melting furnace 100 from entering the vacuum pump during vacuuming, causing equipment damage. Therefore, the utility model preferably has two filter tanks 700, and the negative pressure regulating system for the melting furnace 100 further includes a second three-way valve 702, and the connection relationship between the second three-way valve 702 and the second vacuum pump 201 and another filter tank 700 refers to the connection relationship between the first three-way valve 701 and the first vacuum pump 200 and the filter tank 700. By arranging the filter tank 700, the service life of the first vacuum pump 200 and the second vacuum pump 201 can be extended, and the maintenance cost of the negative pressure regulating system can be reduced.

[0050] In order to optimize the above technical solution, the third switch 600 also includes a third vacuum valve 603, which is arranged between the filter tank 700 and the melting furnace 100. Specifically, when the number of filter tanks 700 is two, the utility model preferably arranges the third vacuum valve 603 between the two filter tanks 700 and the melting furnace 100, and the third vacuum valve 603 is used to control whether the negative pressure pre-position part and the vacuum pumping component can perform the vacuum pumping operation on the melting furnace 100. Further, the negative pressure regulating system also includes a third connecting valve 503, which is used to control the opening and closing of the pipeline between the second vacuum pump 201 and the melting furnace 100. During use, when the negative pressure regulating system needs to be adjusted from the first state to the second state, the melting power supply of the melting furnace 100 is turned on, the first connecting valve 501, the second connecting valve 502, the first energy storage valve 401 and the second energy storage valve 402 are closed, the third connecting valve 503, the first vacuum valve 601, the second vacuum valve 602 and the third vacuum valve 603 are opened, and the first vacuum pump 200 and the second vacuum pump 201 perform a vacuum operation on the melting furnace 100. When the melting reaches a certain degree, the negative pressure regulating system needs to be adjusted from the second state to the third state. At this time, the first energy storage valve 401 and the second The energy storage valve 402 is continuously closed, the third connecting valve 503 and the third vacuum valve 603 are continuously opened, and the first connecting valve 501 and the second connecting valve 502 are opened, so that the vacuum negative pressure tank 300 starts to work, and the melting furnace 100 is vacuumed. At the same time, the first vacuum pump 200 and the second vacuum pump 201 are transferred to the vacuum negative pressure tank 300 and work, and cooperate with the vacuum negative pressure tank 300 to quickly increase the pumping speed, and quickly extract the microbubbles in the transparent layer. After the melting is completed, the vacuum negative pressure tank 300, the first vacuum pump 200 and the second vacuum pump 201 stop running, and all valves are closed.

[0051] The above process realizes the rapid vacuuming operation of the melting furnace 100. By adding the vacuum negative pressure tank 300, the negative pressure environment in the melting furnace 100 is strengthened and stabilized, thereby improving the production quality of the quartz crucible.

[0052] In order to optimize the above technical solution, the negative pressure regulating system for the melting furnace 100 also includes an exhaust valve 800, which is arranged between the melting furnace 100 and the filter tank 700 and is used to discharge gas; and / or, the negative pressure regulating system for the melting furnace 100 also includes a vacuum transmitter 900, which is arranged between the melting furnace 100 and the filter tank 700 and is used to monitor pressure. Specifically, when the negative pressure regulating system is not working or the negative pressure regulating system is in an emergency state, the gas in the negative pressure regulating system can be discharged through the exhaust valve 800 to avoid other accidents, thereby improving the safety of the negative pressure regulating system. Specifically, the vacuum transmitter 900 is used to monitor and control the pressure in a closed environment. It can be arranged in a pipeline or in the melting furnace 100. As long as the pressure can be monitored, the normal operation and safety of the negative pressure regulating system can be ensured. By arranging the drain valve 800 and the vacuum transmitter 900, the safety of the negative pressure regulating system in the working state and the non-working state is improved, which can effectively ensure the production safety and improve the practicality of the negative pressure regulating system.

[0053] In order to optimize the above technical solution, the negative pressure regulating system for the melting furnace 100 also includes a vacuum pressure gauge, which is connected to the negative pressure pre-position part and is used to monitor the pressure of the negative pressure pre-position part. Specifically, the vacuum pressure gauge is used to monitor the internal pressure of the vacuum negative pressure tank 300. The first vacuum pump 200 and the second vacuum pump 201 can perform a vacuum operation on the vacuum negative pressure tank 300 according to the data monitored by the vacuum pressure gauge, and stop vacuuming it after reaching the preset pressure value. Therefore, by arranging the vacuum pressure gauge, the overall operating efficiency of the negative pressure regulating system can be improved.

[0054] In order to optimize the above technical solution, the negative pressure regulating system for the melting furnace 100 also includes a pressure alarm, which is electrically connected to the vacuum pressure gauge and is used to issue a pressure warning. Specifically, the preferred pressure alarm of the utility model is an acousto-optic integrated pressure alarm, which can indicate the vacuum pressure value with a pointer in real time, and can infinitely set and monitor the vacuum pressure alarm value; when the vacuum pressure exceeds the standard, it will output a switch value, triggering the alarm to sound an alarm; it can be optionally battery-powered, and can also monitor the alarm when the power is off. Furthermore, the pressure alarm can also be electrically connected to the vacuum transmitter 900, and when the monitoring value of the vacuum transmitter 900 is different from the normal value, an alarm is issued to further effectively ensure the production safety of the negative pressure regulating system.

[0055] In order to optimize the above technical solution, the number of melting furnaces 100 is one or more. When the number of melting furnaces 100 is two or more, two or more melting furnaces 100 are arranged in parallel. Specifically, in the normal production process, since the voltage may not be able to meet the simultaneous operation of two adjacent melting furnaces 100, when the number of melting furnaces 100 is two or more, the melting furnaces 100 can be operated alternately for production. When the number of melting furnaces 100 is two, a vacuum transmitter 900, an exhaust valve 800 and a vacuum valve can be added to control the pipelines connected thereto separately, that is, the first vacuum pump 200, the second vacuum pump 201 and the vacuum negative pressure tank 300 can be connected to the two melting furnaces 100 respectively through the additional valves and pipelines, and the first vacuum pump 200, the second vacuum pump 201 and the vacuum negative pressure tank 300 can alternately provide stable negative pressure to the two melting furnaces 100, which is more convenient, thereby improving the production efficiency of the quartz crucible. The alternating operation of the melting furnace 100 can also protect the melting furnace 100 and extend its service life.

[0056] The advantages of the utility model are:

[0057] (1) Improved the stability of the negative pressure environment;

[0058] (2) High security;

[0059] (3) High vacuum efficiency.

[0060] It should be noted that the negative pressure regulating system for a melting furnace provided by the utility model can be used in the field of quartz crucible manufacturing technology or other fields. Other fields are any fields other than the field of quartz crucible manufacturing technology. The above is only an example and does not limit the application field of the negative pressure regulating system for a melting furnace provided by the utility model.

[0061] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0062] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0064] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A negative pressure regulating system for a melting furnace, characterized in that: The invention comprises a vacuum pumping component, a negative pressure pre-positioning element, a first switch, a second switch and a third switch, wherein the first switch is arranged between the vacuum pumping component and the negative pressure pre-positioning element, the second switch is arranged between the negative pressure pre-positioning element and the melting furnace, and the third switch is arranged between the vacuum pumping component and the melting furnace; When the negative pressure regulating system is in the first state, the first switch is turned on, the second switch and the third switch are turned off, and the vacuum pumping component performs a vacuum pumping operation on the negative pressure pre-position element; When the negative pressure regulating system is in the second state, the third switch is turned on, the first switch and the second switch are turned off, and the vacuum pumping component performs a vacuum pumping operation on the melting furnace; When the negative pressure regulating system is in the third state, the second switch and the third switch are turned on, the first switch is turned off, and the negative pressure pre-position part and the vacuum pumping assembly simultaneously perform the vacuum pumping operation on the melting furnace.

2. The negative pressure regulating system for a melting furnace according to claim 1, characterized in that: The vacuum pump assembly includes a first vacuum pump and a second vacuum pump, and the negative pressure pre-piece is provided with a first inlet connected to the first vacuum pump and a second inlet connected to the second vacuum pump.

3. The negative pressure regulating system for a melting furnace according to claim 2, characterized in that: The negative pressure pre-installed component is a vacuum negative pressure tank, and the vacuum negative pressure tank is provided with a first outlet and a second outlet which are connected with the melting furnace.

4. The negative pressure regulating system for a melting furnace according to claim 3, characterized in that: The first switch includes a first energy storage valve and a second energy storage valve, the first energy storage valve is arranged between the first inlet and the first vacuum pump, and the second energy storage valve is arranged between the second inlet and the second vacuum pump; And / or, the second switch includes a first connecting valve and a second connecting valve, the first connecting valve is arranged between the first outlet and the melting furnace, and the second connecting valve is arranged between the second outlet and the melting furnace; And / or, the third switch includes a first vacuum valve and a second vacuum valve, the first vacuum valve is arranged between the first vacuum pump and the melting furnace, and the second vacuum valve is arranged between the second vacuum pump and the melting furnace.

5. The negative pressure regulating system for a melting furnace according to claim 1, characterized in that: The negative pressure regulating system for the melting furnace also includes a first three-way valve and a filter tank, wherein the first end of the first three-way valve is connected to the third switch, the second end of the first three-way valve is connected to the second switch, the third end of the first three-way valve is connected to the filter tank, and the filter tank is arranged between the first three-way valve and the melting furnace.

6. The negative pressure regulating system for a melting furnace according to claim 5, characterized in that: The third switch further includes a third vacuum valve, and the third vacuum valve is arranged between the filter tank and the melting furnace.

7. The negative pressure regulating system for a melting furnace according to claim 5, characterized in that: The negative pressure regulating system for the melting furnace further comprises an exhaust valve, which is arranged between the melting furnace and the filter tank and is used to exhaust gas; And / or, the negative pressure regulating system for the melting furnace further comprises a vacuum transmitter, which is arranged between the melting furnace and the filter tank and is used for monitoring the pressure.

8. The negative pressure regulating system for a melting furnace according to claim 1, characterized in that: The negative pressure regulating system for the melting furnace further comprises a vacuum pressure gauge, which is connected to the negative pressure pre-element and is used to monitor the pressure of the negative pressure pre-element.

9. The negative pressure regulating system for a melting furnace according to claim 8, characterized in that: The negative pressure regulating system for the melting furnace further comprises a pressure alarm, which is electrically connected to the vacuum pressure gauge and is used to issue a pressure warning.

10. The negative pressure regulating system for a melting furnace according to claim 1, characterized in that: The number of the melting furnaces is one or more. When the number of the melting furnaces is two or more, the two or more melting furnaces are arranged in parallel.

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