A method for detecting gas tightness of single crystal furnace
By comparing the actual pressure change amount and the standard pressure change amount of the single crystal furnace during the vacuum extraction process, combined with the detection steps of extending the vacuum extraction time, the problem that the existing technology cannot accurately judge the airtight performance of the single crystal furnace is solved, and the accurate judgment of the airtightness of the single crystal furnace and the quality control of the production process is achieved.
Patent Information
- Application Number
- CN202011259857.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-11-12
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2040-11-12
AI Technical Summary
The prior art cannot accurately judge the quality of the airtight performance of a single crystal furnace, especially in the case of a weak air leakage, and it is difficult for traditional methods to distinguish between good and poor airtightness.
A detection method is adopted, including closing the intake valve and exhaust valve of the single crystal furnace, evacuate and detect the actual pressure change amount, and judge the airtightness by comparing the actual pressure change amount with the standard pressure change amount; if the actual pressure change amount is insufficient, the vacuum time will be extended and the detection will be repeated.
This method can accurately judge the airtight performance of single crystal furnaces, avoid misjudgment by traditional methods in the case of weak air leakage, and ensure quality and cost control of the production process.
Smart Images
Figure CN114486107B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of photovoltaic product preparation, and in particular to a method for detecting the air tightness of a single crystal furnace. Background Art
[0002] The single crystal furnace is the main equipment for preparing single crystal ingots. Poor air tightness of the single crystal furnace will seriously affect the crystallization of the single crystal ingot. If the air tightness of the single crystal furnace is poor, air will enter the single crystal furnace during the single crystal pulling process, and the air entering the single crystal furnace will react with the thermal field at high temperature, thereby damaging the thermal field, which will lead to an increase in production costs; in addition, the oxygen in the air will participate in the single crystal pulling process, resulting in a high oxygen content in the single crystal, which will in turn induce single crystal micro-defects, affect the quality of the single crystal, affect the product qualification rate, and further lead to an increase in production costs.
[0003] To avoid the above situation, the air tightness of the single crystal furnace will be checked every time the single crystal furnace is restarted, before cleaning the single crystal furnace, loading raw materials and auxiliary materials, debugging the equipment, and preparing for the chemical reaction. The current method of checking the air tightness of the single crystal furnace in the industry is to evacuate the single crystal furnace to the limit. If the single crystal furnace can be evacuated to the limit pressure within this period of time, that is, the pressure inside the single crystal furnace can be low enough, then the air tightness of the single crystal furnace is judged to be good; if the pressure inside the single crystal furnace cannot reach a low enough level within this time, then the air tightness of the single crystal furnace is judged to be poor.
[0004] This detection method can detect single crystal furnaces with serious leaks. However, in the case of slight leaks, if the single crystal furnace is evacuated for a long enough time, the pressure inside the furnace can be reduced to a low enough level. This means that the current traditional detection method cannot accurately judge the airtightness of the single crystal furnace. Summary of the invention
[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a method for detecting the airtightness of a single crystal furnace, which can accurately judge the quality of the airtightness of the single crystal furnace.
[0006] To achieve the above purpose, the technical solution adopted by the present invention is:
[0007] A method for detecting the air tightness of a single crystal furnace, comprising:
[0008] S1. Close the air inlet valve and exhaust valve of the single crystal furnace;
[0009] S2. Evacuate the single crystal furnace for a duration of T1, and after completion, detect the actual pressure in the single crystal furnace;
[0010] S3. Compare the actual pressure change in the single crystal furnace with the standard pressure change. If the actual pressure change in the single crystal furnace is ≥ the standard pressure change, directly execute step S4;
[0011] S4. Keep the single crystal furnace closed for a period of T2, and then re-detect the actual pressure in the single crystal furnace after completion;
[0012] S5. Compare and judge whether the actual pressure in the single crystal furnace increases. If not, it is judged that the air tightness of the single crystal furnace is good; if yes, it is judged that the air tightness of the single crystal furnace is poor.
[0013] In the above step S3, if the actual pressure change in the single crystal furnace is less than the standard pressure change, step S6 is executed, and the step S6 includes:
[0014] S61. Continue to evacuate the vacuum for a duration of T3, and after completion, detect the actual pressure in the single crystal furnace;
[0015] S62. Compare the actual pressure change in the single crystal furnace with the standard pressure change. If the actual pressure change in the single crystal furnace is ≥ the standard pressure change, then execute steps S4 and S5 in sequence.
[0016] In step S62, the actual pressure change is the actual pressure change in the single crystal furnace within the time T1+T3, and correspondingly, the standard pressure change is the standard pressure change within the time T1+T3; or, the actual pressure change is the actual pressure change in the single crystal furnace within the time T3, and correspondingly, the standard pressure change is the standard pressure change within the time T3.
[0017] In the step S62, if the actual pressure change in the single crystal furnace is less than the standard pressure change, it is determined that the airtightness of the single crystal furnace is poor.
[0018] Said T3≥T1.
[0019] The T3 is set to 6-12 min.
[0020] T3 was set to 7, 8, 9, 10 or 11 min.
[0021] The T1 is set to 4-8 min.
[0022] The T1 is set to 5, 6 or 7 min.
[0023] Said T2≤T1.
[0024] The T2 is set to 3-5 min.
[0025] The beneficial effects of the present invention are:
[0026] 1. Because the present invention adopts the above-mentioned single crystal furnace airtightness detection method, it can accurately judge the airtightness of the single crystal furnace, thereby not only protecting the thermal field, but also ensuring the quality of the pulled single crystal, that is, ensuring the qualified rate of the product and reducing the production cost;
[0027] 2. Because the present invention adopts the above-mentioned single crystal furnace airtightness detection method, compared with the traditional method, the time required is shorter, thereby greatly improving the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 The figure is a principle block diagram of the single crystal furnace air tightness detection method of the present invention. DETAILED DESCRIPTION
[0029] The method for detecting the air tightness of a single crystal furnace of the present invention is described in detail below with reference to the accompanying drawings.
[0030] like Figure 1 As shown, the method for detecting the air tightness of a single crystal furnace of the present invention comprises:
[0031] S1. Close the air inlet valve and exhaust valve of the single crystal furnace;
[0032] S2. Evacuate the single crystal furnace for a duration of T1, and after completion, detect the actual pressure in the single crystal furnace;
[0033] S3. Compare the actual pressure change in the single crystal furnace with the standard pressure change. If the actual pressure change in the single crystal furnace is ≥ the standard pressure change, directly execute step S4;
[0034] S4. Keep the single crystal furnace closed for a period of T2, and then re-detect the actual pressure in the single crystal furnace after completion;
[0035] S5. Compare and judge whether the actual pressure in the single crystal furnace increases. If not, it is judged that the air tightness of the single crystal furnace is good; if yes, it is judged that the air tightness of the single crystal furnace is poor.
[0036] Because if the actual pressure does not increase, it means that no new gas enters the single crystal furnace within the T2 time, that is, there is no leak in the single crystal furnace to allow external gas to enter it, which indicates that the single crystal furnace has good air tightness. On the contrary, if the actual pressure in the single crystal furnace increases, it means that air enters the single crystal furnace during the air-tight time period of T2, and the air inlet valve and exhaust valve of the single crystal furnace are closed, so under normal conditions, no air will enter the single crystal furnace through the valve, only the single crystal furnace leaks, and air enters the single crystal furnace through the leaking place, which indicates that the single crystal furnace has poor air tightness; that is to say, even if the single crystal furnace has only a slight leak, the single crystal furnace will enter air during the air-tight time period of T2, thereby causing the increase of the actual pressure in the single crystal furnace. Therefore, the detection method of the present invention can accurately detect the quality of the airtightness of the single crystal furnace, thereby not only protecting the thermal field, but also ensuring the quality of the drawn single crystal, that is, ensuring the qualified rate of the product and reducing the production cost.
[0037] In the above step S3, if the actual pressure change in the single crystal furnace is less than the standard pressure change, step S6 is executed, and the step S6 includes:
[0038] S61. Continue to evacuate the vacuum for a duration of T3, and after completion, detect the actual pressure in the single crystal furnace;
[0039] S62. Compare the actual pressure change in the single crystal furnace with the standard pressure change. If the actual pressure change in the single crystal furnace is ≥ the standard pressure change, then execute steps S4 and S5 in sequence.
[0040] In the above step S62, if the actual pressure change in the single crystal furnace is less than the standard pressure change, it is determined that the airtightness of the single crystal furnace is poor.
[0041] In the above step S3, the actual pressure change in the single crystal furnace is compared with the standard pressure change, that is, the actual pressure change in the single crystal furnace during time T1 is compared with the standard pressure change.
[0042] With such arrangement, even if the first comparison result is unfavorable for the determination of the airtightness of the single crystal furnace, further determination can be made through subsequent operations, thereby avoiding errors in the determination of the airtightness of the single crystal furnace and ensuring the accuracy of the determination result.
[0043] In this embodiment, the actual pressure change in the single crystal furnace during the T1 time refers to the difference between the actual pressure in the single crystal furnace after vacuuming for T1 time (represented by P1) and the pressure in the single crystal furnace before vacuuming (represented by P0, i.e., conventional atmospheric pressure), which is expressed by the following formula:
[0044] △=P1-P0
[0045] The △ represents the actual pressure change in the single crystal furnace during the time T1.
[0046] The standard pressure change during the T1 time refers to the difference between the pressure of the single crystal furnace after vacuuming for T1 time (represented by P1′) and the pressure in the single crystal furnace before vacuuming (also the conventional atmospheric pressure P0), assuming that the single crystal furnace has good airtightness, and is expressed by the following formula:
[0047] △′=P1′-P0
[0048] The △′ represents the change in standard pressure in the single crystal furnace during time T1.
[0049] The comparison between the actual pressure change in the single crystal furnace during the time T1 and the standard pressure change is the comparison between △ and △′.
[0050] In the above step S62, the actual pressure change can be the actual pressure change in the single crystal furnace within the time T1+T3, and correspondingly, the standard pressure change is the standard pressure change within the time T1+T3; the actual pressure change can also be the actual pressure change in the single crystal furnace within the time T3, and correspondingly, the standard pressure change is the standard pressure change within the time T3.
[0051] Specifically, P2 represents the actual pressure in the single crystal furnace after the vacuum is continuously drawn for T3 time in step S61, and the actual pressure change Δ1 in the single crystal furnace during the time T1+T3 can be expressed by the following formula:
[0052] △1=P2-P0
[0053] Correspondingly, the standard pressure change within the time T1+T3 refers to the difference between the pressure of the single crystal furnace after vacuuming T1+T3 (represented by P2′) and the pressure in the single crystal furnace before vacuuming (also the conventional atmospheric pressure P0), assuming that the single crystal furnace has good airtightness, and is expressed by the following formula:
[0054] △1′=P2′-P0
[0055] Thus, in the above step S62, the actual pressure change in the single crystal furnace is compared with the standard pressure change, which is to compare △1′ with △1.
[0056] If the actual pressure change is the actual pressure change in the single crystal furnace within T3, and the standard pressure change is the standard pressure change within T3, then the actual pressure change Δ2 and the standard pressure change Δ2′ can be expressed by the following formulas:
[0057] △2=P2-P1
[0058] △2′=P2′-P1′
[0059] Thus, in the above step S62, the actual pressure change in the single crystal furnace is compared with the standard pressure change, which is to compare △2′ with △2.
[0060] In the above step S5, a comparison is made to determine whether the actual pressure in the single crystal furnace increases, that is, the pressure before and after the gas is closed in the single crystal furnace is compared. Specifically, P3 represents the actual pressure after the air is closed for T2 time. When steps S4 and S5 are directly executed after the above-mentioned step S3, the pressures before and after the air is closed in the single crystal furnace are compared, that is, P3 and P1 are compared. If P3≤P1, it means that the actual pressure after the air is closed has not increased compared with that before the air is closed. In this case, it is determined that the airtightness of the single crystal furnace is good; on the contrary, if P3>P1, it means that air has entered the single crystal furnace during the air-closing time, and the airtightness of the single crystal furnace is poor; if steps S4 and S5 are executed after the above-mentioned steps S61 and S62, the pressures before and after the air is closed in the single crystal furnace are compared, that is, P3 and P2 are compared. If P3≤P2, it is determined that the airtightness of the single crystal furnace is good. If P3>P2, it means that air has entered the single crystal furnace during the air-closing time, and the airtightness of the single crystal furnace is poor.
[0061] In this embodiment, T1 is set to 4-8 minutes, preferably, T1 is set to 5, 6 or 7 minutes. T1 is set in this way, the time is not too long, but after the vacuum is evacuated for this time, the pressure in the single crystal furnace can change significantly, which is sufficient for comparative analysis.
[0062] Preferably, T2≤T1. In this embodiment, T2 is set to 3-5 minutes. Similarly, this time is not too long, but if the air tightness of the single crystal furnace is poor, this time is enough to determine whether the pressure of the single crystal furnace changes.
[0063] Preferably, T3 ≥ T1. In this embodiment, T3 is set to 6-12 min. T3 can be set to 7, 8, 9, 10 or 11 min. When T3 is set in this way, the time is not too long, and the pressure in the single crystal furnace can change significantly, which is sufficient for comparative analysis.
[0064] As described above, because the present invention adopts the detection method of the above steps, the time of the relevant steps can be set as above, and then for the detection method of the present invention, to judge the airtightness of a single crystal furnace, it takes only 25 minutes at most and 7 minutes at least; while if the traditional method is adopted, for a single crystal furnace of the same size, even if its airtightness is very good, it takes at least 40-60 minutes to evacuate it to the limit. Therefore, compared with the traditional technology, the detection method of the present invention greatly reduces the time required for detection, thereby greatly improving production efficiency.
[0065] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.
Claims
1. A method for detecting the air tightness of a single crystal furnace, characterized in that: include S1. Close the air inlet valve and exhaust valve of the single crystal furnace; S2. Evacuate the single crystal furnace for a duration of T1, and after completion, detect the actual pressure in the single crystal furnace; S3. Compare the actual pressure change in the single crystal furnace with the standard pressure change. If the actual pressure change in the single crystal furnace is ≥ the standard pressure change, then directly execute step S4; S4. Keep the single crystal furnace closed for a period of T2, and then re-detect the actual pressure in the single crystal furnace after completion; S5. Compare and judge whether the actual pressure in the single crystal furnace increases. If not, it is determined that the single crystal furnace has good air tightness; if yes, it is determined that the single crystal furnace has poor air tightness; In the above step S3, if the actual pressure change in the single crystal furnace is less than the standard pressure change, step S6 is executed, and the step S6 includes: S61. Continue to evacuate the vacuum for a duration of T3, and after completion, detect the actual pressure in the single crystal furnace; S62. Compare the actual pressure change in the single crystal furnace with the standard pressure change. If the actual pressure change in the single crystal furnace is ≥ the standard pressure change, then execute steps S4 and S5 in sequence; In the step S62, if the actual pressure change in the single crystal furnace is less than the standard pressure change, it is determined that the airtightness of the single crystal furnace is poor; In the step S62, the actual pressure change is the actual pressure change in the single crystal furnace within the time T1+T3, and correspondingly, the standard pressure change is the standard pressure change within the time T1+T3; or, the actual pressure change is the actual pressure change in the single crystal furnace within the time T3, and correspondingly, the standard pressure change is the standard pressure change within the time T3; T3≥T1, T2≤T1; T3 is set to 6-12min, T1 is set to 4-8min, and T2 is set to 3-5min.
2. The method for detecting the air tightness of a single crystal furnace according to claim 1, characterized in that: T3 was set to 7, 8, 9, 10 or 11 min.
3. The method for detecting the air tightness of a single crystal furnace according to claim 1 or 2, characterized in that: The T1 is set to 5, 6 or 7 min.
Citation Information
Patent Citations
Refrigerator sealing performance detection method and device and medium
CN111238746A