Multi-process equipment control system for quartz crucible production based on PLC control

Abstract

The present invention belongs to the technical field of production control, and specifically discloses a multi-process equipment control system for quartz crucible production based on PLC control, which includes a sintering equipment monitoring module, a conveying equipment control module, a cooling equipment control module, a database and an equipment central control terminal. The present invention monitors the sintering process of the sintering equipment, and performs conveying equipment control analysis and cooling equipment control analysis according to the monitoring results, thereby realizing the linkage analysis of multiple processes in the quartz crucible production process, solving the problem of weak linkage in the current quartz crucible production control, avoiding the shortcomings of the current single control object, and thus facilitating the guarantee of continuity and stability in the quartz crucible production process, and by combining the analysis results of the sintering equipment and the control and transmission indicators of the conveying equipment, the production status of the front-end process link is fully combined, and the comprehensive parameter control of the quartz crucible is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of production control, and in particular relates to a multi-process equipment control system for quartz crucible production based on PLC control. Background Art

[0002] Quartz crucibles are widely used in semiconductor, solar photovoltaic industries and laboratory applications because they can withstand high temperatures and are chemically stable. In the production of quartz crucibles, multiple processes are usually used to ensure the quality and performance of the product, which highlights the necessity and importance of multi-process equipment control.

[0003] Prior art, such as Chinese patent application with publication number CN203643795U, discloses a total control system for a quartz crucible melting machine, which includes a main controller and a melting control device, a molding control device and other control devices connected to the main controller. The other control devices are composed of a circulating fan and a temperature sensor. The quartz crucible melting machine is mainly controlled by a mechanical control circuit. The overall dynamic monitoring and control is not highly adjustable.

[0004] For example, the Chinese patent application with publication number CN203366092U discloses a control system for an ultra-low expansion glass-ceramic production line, which includes a melting furnace, a molding machine, an annealing furnace, and a crystallization furnace. The control system includes an industrial computer, a programmable temperature controller, and a programmable logic controller, wherein the industrial computer is connected to the programmable temperature controller and the programmable logic controller, and the programmable logic controller is connected to the melting furnace, the molding machine, the annealing furnace, and the crystallization furnace. Although it solves the problem of automatic control of the ultra-low expansion glass-ceramic production line and realizes effective control of the ultra-low expansion glass-ceramic production line, it also adopts a local precision improvement target-oriented control regulation.

[0005] Regarding the above two technical solutions, it is obvious that the current preparation control of quartz crucibles mainly focuses on automation and precise control, but there are still the following deficiencies in automation and precise control: 1. The linkage is not strong. The production of quartz crucibles is mostly controlled by the linkage of multiple equipment and multiple processes. Currently, this aspect is less considered and is a single control object, which cannot guarantee the continuity and stability of the quartz crucible production process.

[0006] 2. The control accuracy of production parameters is not high. Currently, production indicators are controlled only according to the current process link, and comprehensive parameter control is not carried out in combination with the production status of the front-end process link. As a result, the effect of production control is not significantly improved, and the production quality cannot be effectively guaranteed. At the same time, it is impossible to further reduce the scrap rate of production. Summary of the invention

[0007] In view of this, in order to solve the problems raised in the above background technology, a multi-process equipment control system for quartz crucible production based on PLC control is proposed.

[0008] The purpose of the present invention can be achieved through the following technical solutions: The present invention provides a multi-process equipment control system for quartz crucible production based on PLC control, the system comprising: a sintering equipment monitoring module, which is used to monitor the sintering temperature and atmosphere pressure corresponding to each sintering time point in each sintering stage of the quartz crucible during the sintering process, as well as the sintering state information of the sintered product after the sintering equipment completes sintering, to form a sintering data set.

[0009] The conveying equipment control module is used to import the initial conveying setting indicators of the conveying equipment, and judge the conveying equipment regulation demand based on the sintering data set. If the judgment result is demand regulation, the control conveying indicator of the conveying equipment is confirmed. If the judgment result is that no regulation is required, the initial conveying setting indicator is used as the control conveying indicator, and the conveying equipment is started for conveying.

[0010] The cooling equipment control module is used to import the initial setting cooling index of the cooling equipment, and judge the cooling control demand of the cooling equipment based on the control transmission index of the transmission equipment and the sintering data set. If the judgment result is demand control, the control cooling index of the cooling equipment is confirmed. If the judgment result is that no control is required, the initial setting cooling index is used as the control cooling index, and the cooling equipment is started for cooling.

[0011] The database is used to store the appropriate atmosphere pressure of the quartz crucible in each sintering stage and to store the reference temperature change curve of the quartz crucible in each sintering stage.

[0012] The equipment central control terminal includes a sintering equipment control unit, a conveying equipment control unit and a cooling equipment control unit, which are used to control the operation of the sintering equipment, the conveying equipment and the cooling equipment accordingly through PLC.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention monitors the sintering process of the sintering equipment and performs control analysis of the conveying equipment and the cooling equipment according to the monitoring results, thereby realizing the linkage analysis of multiple processes in the production process of the quartz crucible, solving the problem of weak linkage in the current production control of the quartz crucible, avoiding the shortcomings of the current single control object, and thus facilitating the guarantee of continuity and stability in the production process of the quartz crucible.

[0014] (2) The present invention determines the need for control of the conveying equipment by analyzing the consistency of the sintering temperature change, the consistency of the sintering atmosphere pressure change and the consistency of the sintering product state change. At the same time, when determining the need for cooling control of the cooling equipment, the present invention combines the analysis results of the sintering equipment and the control and transmission indicators of the conveying equipment, fully combines the production status of the front-end process links, realizes the comprehensive parameter control of the quartz crucible, and thus improves the production parameter control accuracy of the quartz crucible, thereby significantly improving the subsequent production control effect, and at the same time, the production quality can be effectively guaranteed, thereby further reducing the scrap rate of production.

[0015] (3) When confirming the control cooling index of the cooling equipment, the present invention controls the cooling time, cooling mode and cooling wind speed by combining the temperature distribution difference of the sintered product, thereby greatly improving the uniformity of cooling, thereby reducing the internal stress caused by uneven cooling, thereby improving product quality, and at the same time making the cooling process more efficient and stable, avoiding local overcooling or overheating, and ensuring the stability of the physical and chemical properties of the product. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 1 This is a schematic diagram of the connection of the system modules of the present invention.

[0018] Figure 2 It is a schematic diagram of the structure of the central control terminal of the device of the present invention.

[0019] Figure 3 This is a schematic diagram of the overall flow of controlling the multi-process equipment used in the production of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0021] See also Figure 1 and Figure 3As shown, the present invention provides a multi-process equipment control system for quartz crucible production based on PLC control, the system comprising: a sintering equipment monitoring module, a conveying equipment control module, a cooling equipment control module, a database and an equipment central control terminal.

[0022] In the above, the conveying equipment control module is respectively connected to the sintering equipment monitoring module, the cooling equipment control module, the database and the equipment central control terminal, and the cooling equipment control module is also connected to the equipment central control terminal.

[0023] The sintering equipment monitoring module is used to monitor the sintering temperature and atmosphere pressure of the quartz crucible at each sintering stage corresponding to each sintering time point during the sintering process, as well as the sintering state information of the sintered product after the sintering equipment completes sintering, to form a sintering data set.

[0024] It can be understood that the sintering equipment is mainly used to heat powdered or granular materials to bond their particles together, thereby forming an integral material with a certain shape and strength. It is mainly composed of multiple elements such as heating elements, furnaces, atmosphere control elements, temperature control elements, loading and unloading elements, and illustratively, the heating elements can be resistance wires and induction coils, etc. The loading and unloading elements refer to devices used to put materials into and take out of the furnace.

[0025] Specifically, the sintering temperature and the atmosphere pressure are monitored by the temperature sensor and the pressure sensor respectively installed in the furnace of the sintering equipment. The sintering state information includes the monitoring values ​​of each sintering defect monitoring index and infrared thermal imaging.

[0026] Among them, the monitoring values ​​of various sintering defect monitoring indicators can be obtained by monitoring one or more devices such as high-definition cameras and x-ray detectors, and infrared thermal imaging can be obtained by monitoring with infrared thermal imagers.

[0027] It should be added that the sintering defect monitoring indicators include cracks and holes, among which the monitoring value of cracks is the number of cracks, and the monitoring value of holes is the number of holes.

[0028] The conveying equipment control module is used to import the initial conveying setting indicators of the conveying equipment, and judge the control demand of the conveying equipment based on the sintering data set. If the judgment result is that the control is required, the control conveying indicator of the conveying equipment is confirmed. If the judgment result is that no control is required, the initial conveying setting indicator is used as the control conveying indicator, and the conveying equipment is started for conveying.

[0029] It is understandable that the transmission device can be a push rod or a high temperature resistant conveyor belt, and can be configured according to specific scenarios and is not specifically limited here.

[0030] It should be added that the initial transmission setting indicators include but are not limited to the initial transmission speed and the set transmission speed control range.

[0031] It should also be added that after the sintering process, the structure and performance of the quartz crucible are still in an unstable state, especially at high temperatures, the physical and chemical properties of the material may change. Therefore, the speed of the conveying equipment should be stable to avoid deformation or damage to the product due to sudden acceleration or deceleration. At the same time, the conveying speed control helps to ensure that the quartz crucible is cooled evenly during the cooling process, avoiding internal stress accumulation or material cracking due to excessive temperature gradients. And through precise speed control, not only can the production efficiency and product quality of the quartz crucible be improved, but also energy savings and reduced equipment maintenance costs can be achieved. It can be seen that the speed control of the conveying equipment is an indispensable and important link in the production process of the quartz crucible. Therefore, after the sintering equipment operation is completed, it is necessary to judge the conveying speed control of the conveying equipment and confirm the control of the conveying indicators according to the sintering state to ensure production quality.

[0032] Specifically, the transmission equipment regulation demand judgment includes: A1, using the sintering time point as the horizontal coordinate and the sintering temperature as the vertical coordinate, drawing the monitoring temperature change curve of each sintering stage, and extracting the reference temperature change curve of the quartz crucible in each sintering stage during the sintering process from the database, and calculating the sintering temperature change consistency, which is recorded as .

[0033] A2. Calculate the standard deviation of the atmosphere pressure at each sintering time point in the same sintering stage, and use the calculation result as the atmosphere pressure deviation.

[0034] A3. Calculate the average of the atmosphere pressures at each sintering time point in the same sintering stage to obtain the average atmosphere pressure corresponding to each sintering stage, and extract the appropriate atmosphere pressure of the quartz crucible in each sintering stage from the database.

[0035] A4. The atmosphere pressure deviation, average atmosphere pressure and suitable atmosphere pressure of each sintering stage are recorded as , and , Indicates the sintering stage number, .

[0036] A5. Calculate the consistency of sintering atmosphere pressure change, recorded as , , To set the reference atmosphere pressure difference, is the number of sintering stages.

[0037] It should be added that in the production process of quartz crucibles, changes in atmosphere pressure will have a significant impact on the microstructure, density, porosity and final performance of the material. At the same time, changes in atmosphere pressure will also have a greater impact on the temperature uniformity in the blast furnace, thereby affecting the uniformity of heat received by the quartz crucible during the sintering process and the density of the quartz crucible. Therefore, an analysis of the consistency of the change in atmosphere pressure is carried out.

[0038] It should also be added that, ideally, the atmospheric pressure should be within a certain range with little deviation, i.e. The value tends to 0 when When the value is large, it indicates that the atmospheric pressure difference is large. At this time, the error of using the average atmospheric pressure to calculate is large. The value of Set as a correction factor corresponding to the average atmosphere pressure.

[0039] A6. Extract the monitoring values ​​and infrared thermal images of each sintering defect monitoring index from the sintering state information, and extract the number of temperature distribution areas and the temperature values ​​corresponding to each temperature distribution area from the infrared thermal image, and calculate the consistency of the sintering product state change, which is recorded as ;

[0040] A7. If , and If there is an item in the table that is less than the corresponding reference value, the demand control is used as the judgment result. , and If both are greater than or equal to the set reference value, no adjustment is required as the judgment result.

[0041] It should be added that if , and The corresponding reference values ​​of can be set to 0.2, 0.5 and 0.1 respectively, and The specific value can be 0.2 Pa.

[0042] Further, regarding the calculation of the sintering temperature change consistency in step A1, it includes: A11, setting the temperature change consistency evaluation factor of each sintering stage, denoted as .

[0043] A12. Overlap and compare the monitored temperature change curve of each sintering stage with the corresponding reference temperature change curve to obtain the overlap curve length, recorded as , the length of the monitoring temperature change curve at each sintering stage is recorded as ,Will As the temperature change overlap ratio of each sintering stage.

[0044] A13. The sintering stages whose temperature change coincidence ratio is greater than the set reference temperature change coincidence ratio are recorded as matching stages, the number of matching stages is counted, and the ratio of the number of matching stages to the number of sintering stages is recorded as the sintering temperature change matching degree.

[0045] Understandably, the temperature change matching evaluation factor for each sintering stage set in step A11 includes: Y1, for each sintering stage, statistically monitoring the slope, amplitude and number of fluctuation points of the temperature change curve and the reference temperature change curve.

[0046] Y2. Use the slope, amplitude and number of fluctuation points of the monitored temperature change curve as each monitoring comparison item, and use the slope, amplitude and number of fluctuation points of the reference temperature change curve as each reference comparison item, and compare each monitoring comparison item with each reference comparison item one by one.

[0047] Y3. If the difference between a monitoring comparison item and the corresponding reference item is within the set allowable range, the monitoring comparison item will be recorded as a matching item. Otherwise, the monitoring comparison item will be recorded as a deviation item. The number of matching items in each sintering stage will be counted.

[0048] Y4. If the number of matching items in a sintering stage is 3, 0 is used as the temperature change matching evaluation factor of the sintering stage; otherwise, the sintering stage is recorded as a deviation stage.

[0049] Y5. The number of matching items in the deviation phase is recorded as , and the difference between each deviation term and the corresponding reference term in the deviation phase is recorded as , Indicates Deviation terms, .

[0050] Y6, set the temperature change matching evaluation factor in the deviation stage, denoted as , , and They represent the weight of the number of matching items in the deviation stage and the weight of the difference between each deviation item and the corresponding reference item in the deviation stage, To set the The reference deviation value of the deviation item, , represents the number of deviation terms, .

[0051] It should be added that the matching item ratio reflects the degree of matching between the monitored temperature change curve and the reference temperature change curve in multiple dimensions. It focuses on how many comparison items are within the set allowable range as a whole. Specifically, the higher the matching item ratio, the higher the degree of matching in multiple dimensions, and the overall temperature change curve is closer to the ideal state, which determines the breadth of matching of temperature changes and reflects the degree of deviation in those comparison items that do not meet the matching standards. It focuses on the degree to which specific deviation items deviate from the ideal state. Specifically, the larger the deviation value, the more serious the deviation in these dimensions, which determines the degree of deviation of the temperature change. For the product of quartz crucible, the overall temperature change requirements are more stringent. Therefore, the weight of the matching item ratio is set slightly larger than the weight of the deviation value of the deviation item. For example, and The values ​​can be 0.55 and 0.45 respectively.

[0052] It should also be added that when the deviation term is a slope, the reference deviation value of the deviation term can be 0.1, when the deviation term is an amplitude, the reference deviation value of the deviation term can be 10°C, and when the deviation term is the number of fluctuation points, the reference deviation value of the deviation term can be 2.

[0053] It is understandable that the quartz crucible usually goes through multiple sintering stages during the sintering process. These stages are designed to ensure that the material can be uniformly densified at high temperatures while avoiding defects caused by thermal stress. Exemplarily, the sintering stages include but are not limited to a preheating stage, a low-temperature sintering stage, a medium-temperature sintering stage, a high-temperature sintering stage, and a heat-insulating sintering stage.

[0054] In a specific embodiment, there are certain differences in the temperature range and change trend of different sintering stages. For example, the temperature in the preheating stage gradually increases, the moisture and volatile substances in the material are gradually removed, the temperature rise rate is slow, and the temperature in the low-temperature sintering stage gradually increases to about 600°C to remove the residual organic matter and start a slight densification process. The temperature rise rate is slightly faster, and the temperature in the medium-temperature sintering stage is further increased to about 1000°C, which accelerates the densification process of the material and reduces the porosity. The temperature rise rate is moderate, and the temperature in the high-temperature sintering stage reaches the highest sintering temperature, such as 1000°C-1500°C or higher, to ensure that the material is fully densified and optimize the microstructure. The temperature rise rate remains stable until the set temperature is reached, and the insulation sintering stage drops from the highest sintering temperature to room temperature to ensure that the material is evenly cooled during the cooling process to avoid stress due to excessive temperature gradients. Therefore, it is necessary to combine the temperature changes in each sintering stage to conduct a comprehensive sintering temperature change analysis, so as to facilitate the detailed display of the specific temperature characteristics of the sintering process of the quartz crucible.

[0055] Furthermore, regarding the calculation of the consistency of the state change of the sintered product in step A6, it includes: A61, comparing the monitoring value of each sintering defect monitoring indicator with the reference monitoring value set for each sintering defect monitoring indicator.

[0056] A62. The sintering defect monitoring index whose monitoring value is greater than or equal to the reference monitoring value is marked as the confirmed defect index, the number of confirmed defect indexes is counted, and the ratio of the number of confirmed defect indexes to the number of sintering defect monitoring indexes is taken as the defect ratio, recorded as .

[0057] A63. Filter out the highest temperature value and the lowest temperature value from the temperature values ​​corresponding to each temperature distribution area, record the difference between the two as the temperature difference, and record the temperature difference and the number of temperature distribution areas as and .

[0058] A64. Calculate the consistency of the state change of the sintered finished product , , , and They are respectively expressed as the weights corresponding to the defect ratio, temperature difference and number of temperature distribution areas, , and They represent the defect ratio, temperature difference and number of temperature distribution areas of the set reference respectively. .

[0059] It should be added that if the temperature difference of the sintered product is high, it means that the material needs longer to cool to a safe handling temperature. In this case, the speed of the conveying equipment needs to be slowed down appropriately to ensure that the material can be evenly cooled during the conveying process to avoid stress concentration or cracking caused by insufficient cooling. And the finished product with uneven temperature needs to slow down the conveying speed to ensure the uniformity and stability of the material during the cooling process. At the same time, when there are certain defects in the sintered product, it will affect its stress distribution during the cooling process. Therefore, it is necessary to slow down the conveying speed to reduce stress concentration. The state consistency of the sintered product is analyzed from three dimensions: the maximum temperature difference of the sintered product, the temperature distribution, and the sintering defects.

[0060] It should be added that the defect ratio is usually a key indicator to measure the quality of sintered products. A higher defect ratio means that there are more defects such as pores, holes, cracks, etc. in the finished product, which directly affects the subsequent transmission settings. Therefore, the defect ratio is set to have the largest weight. The temperature difference reflects the consistency and degree of deviation of the temperature of each part during the sintering process. A large temperature difference may cause the material to produce a larger uneven stress distribution during the cooling process, and the number of temperature distribution areas reflects the uniformity of the temperature distribution inside the material during the sintering process. The existence of multiple temperature distribution areas may cause uneven thermal stress distribution inside the material. Therefore, both the temperature difference and the number of temperature distribution areas affect the thermal stress distribution and thus affect the transmission settings. Therefore, the weights corresponding to the temperature difference and the number of temperature distribution areas are set to be the same. For example, , and The possible values ​​are 0.4, 0.3 and 0.3 respectively.

[0061] In a specific embodiment, the reference defect ratio can be set to a specific value of 0.1, the reference temperature difference can be set to a specific value of 10°C, and the reference number of temperature distribution areas can be set to a specific value of 2, wherein the reference defect ratio, temperature difference and number of temperature distribution areas can be set according to the sintering specification of the quartz crucible, wherein the sintering specification of the quartz crucible is provided by the manufacturer of the quartz crucible, and at the same time, the reference monitoring values ​​of each sintering defect monitoring indicator can also be provided by the manufacturer of the quartz crucible or comprehensively set according to experience, and it should be noted that the values ​​given in the present invention are only reference values ​​under normal circumstances, and can be adjusted accordingly according to the sintering specification of the quartz crucible in specific actual scenarios.

[0062] In a specific embodiment, setting The purpose of the function calculation is to ensure the unity of the analysis between each parameter, that is, to avoid interference with the overall calculation result when the calculation results between the parameters have opposite signs. For example, when the defect ratio is greater than the reference defect ratio and the temperature difference is less than the reference temperature difference, if the difference between the temperature difference and the reference temperature difference exceeds the difference between the defect ratio and the reference defect ratio, the overall calculation result will weaken the influence of the defect ratio. Therefore, when the value is less than 0, it is directly assigned 0 for comprehensive analysis. The application principle of the function is the same and will not be repeated here.

[0063] In another specific embodiment, determining the control transmission index of the transmission device includes: B1, traversing , and , and set the overall deviation factor of the sintering state, recorded as .

[0064] Among them, setting the overall deviation factor of the sintering state includes: , and The items that are smaller than the corresponding reference values ​​are recorded as missing items, and the number of missing items is counted and recorded as .

[0065] Calculate separately , and The difference between the set corresponding reference value is recorded as , and .

[0066] Set the overall deviation factor of the sintering state , .

[0067] B2. Extract the initial transmission speed and the set transmission speed control interval from the initial transmission setting index, and record the lower limits of the initial transmission speed and the set transmission speed control interval as and .

[0068] B3. Calculate and confirm the control transmission speed of the transmission equipment , ,Will As a control transmission indicator for transmission equipment.

[0069] It should be added that the sintering temperature variation is consistent with , Sintering atmosphere pressure change consistency The consistency with the state change of sintered finished product Will affect the control of the transmission equipment. If the temperature is too low, it means that the temperature change has not reached the expected level. The conveying speed can be adjusted to extend or shorten the residence time of the material in the high temperature area, thereby ensuring the quality of the finished product. If the pressure is too low, it means that the atmosphere pressure has not reached the expected level. The conveying speed can be adjusted to ensure that the material stays under the specific pressure for a sufficient time. The conveying speed can be slowed down to make the material stay under the specific pressure for a longer time to ensure the stability of the atmosphere pressure. When it is lower, it means that the finished product status has not met expectations. The material flow in the entire sintering process can be optimized by adjusting the conveying speed. For example, the conveying speed can be slowed down to allow the material to stay longer in the critical sintering stage. The conveying equipment not only determines the rate at which the quartz crucible enters the sintering equipment, but also determines the rate at which it is conveyed to the cooling equipment. When the sintering state of the sintering equipment is not good, it is necessary to control the sintering time of the next batch of quartz crucibles to be sintered, and it is also necessary to increase the controllable time of the cooling control, that is, to reduce the conveying speed of the conveying equipment for better cooling.

[0070] In order to facilitate further analysis, the quartz crucible production can be set up as a continuous sintering furnace. After the material enters the furnace from the entrance, it passes through the sintering zone and the cooling zone in turn. Each zone has a specific temperature setting and is moved by a conveying device. If the temperature change in the sintering zone is not consistent enough, the speed at which the material enters the sintering zone can be slowed down so that the material stays in the sintering zone for a longer time, thereby achieving a better temperature change consistency.

[0071] It is also understandable that the space of the sintering furnace is limited. If the residence time is increased, it may cause material accumulation in the furnace, affecting the processing of subsequent batches. At the same time, the temperature distribution in the sintering zone must be uniform. If the material residence time is too long, it may cause local overheating or overcooling, affecting the sintering quality. Therefore, by adjusting the conveying speed of the conveying equipment to increase the residence time, the effect on production efficiency and sintering quality is small, which is a common adjustment method. Therefore, during mass production, the production quality and efficiency can be guaranteed as much as possible, and it is also more energy-saving and convenient.

[0072] The cooling equipment control module is used to import the initial setting cooling index of the cooling equipment, and judge the cooling control demand of the cooling equipment based on the control transmission index of the transmission equipment and the sintering data set. If the judgment result is demand control, the control cooling index of the cooling equipment is confirmed. If the judgment result is that no control is required, the initial setting cooling index is used as the control cooling index, and the cooling equipment is started for cooling.

[0073] It can be understood that the cooling equipment is used to quickly cool the material after sintering or other heat treatment to the required temperature to achieve the performance requirements of the final product, and is assembled from multiple components such as a cooling medium supply component, a cooling chamber, and a cooling medium control component. Among them, the cooling medium in the production process of the quartz crucible usually refers to air, that is, air is used by default.

[0074] Specifically, the initial setting cooling indicators include but are not limited to the initial setting cooling time, the initial setting cooling wind speed, the initial setting cooling mode, and the number of setting cooling stages for stage cooling when the initial setting cooling mode is stage cooling.

[0075] Specifically, the cooling equipment cooling control demand judgment is carried out, including: extracting the overall deviation factor of the sintering state .

[0076] like , and the judgment result is that no regulation is needed.

[0077] If the overall deviation factor of the sintering state Greater than or equal to the set reference sintering state overall deviation factor , then demand regulation is taken as the judgment result.

[0078] like , compare the control transmission speed of the transmission device with its initial transmission speed, and use the ratio as the transmission speed reduction ratio, recorded as .

[0079] The initial transmission time of the sintering equipment and cooling equipment is extracted from the initial transmission setting index and recorded as ,Will As the increase in cooling time, record it as .

[0080] calculate and The difference is taken as the sintering deviation difference, and is matched and compared with the set reference increase cooling time to obtain the matching reference increase cooling time, which is recorded as .

[0081] like , the judgment result is that no regulation is needed, otherwise the judgment result is that regulation is needed.

[0082] It should be added that when the state of the sintered quartz crucible does not deviate much from the ideal state, the cooling demand can be met to a certain extent by slowing down the speed of the conveying equipment and increasing the residence time of the material in the cooling area. When the state of the sintered quartz crucible deviates greatly from the ideal state, additional regulation of the cooling area is required. Therefore, the overall deviation factor of the sintering state is taken as the first judgment factor.

[0083] In one specific implementation, the overall deviation factor of the sintering state is Specifically, the value may be 0.5, and each reference increase in cooling time may correspond to an overall deviation factor difference of the sintering state, which may be obtained through comprehensive design through experience or the application specifications of the cooling equipment, wherein the application specifications of the cooling equipment are provided by the manufacturer of the cooling equipment.

[0084] The embodiment of the present invention determines the need for regulating the conveying equipment by analyzing the consistency of the sintering temperature change, the consistency of the sintering atmosphere pressure change and the consistency of the sintering product state change. At the same time, when determining the need for cooling regulation of the cooling equipment, the embodiment of the present invention combines the analysis results of the sintering equipment and the control and conveying indicators of the conveying equipment, fully combines the production status of the front-end process links, realizes the comprehensive parameter control of the quartz crucible, and thus improves the production parameter control accuracy of the quartz crucible, thereby significantly improving the subsequent production control effect, and at the same time, the production quality can also be effectively guaranteed, thereby facilitating further reducing the scrap rate of production.

[0085] In another specific embodiment, the control cooling index of the cooling device is determined, including: R1, calculating the standard deviation of the temperature values ​​corresponding to each temperature distribution area, and taking the calculation result as the temperature distribution difference of the sintered product, recorded as .

[0086] R2, if ,when When , the initial setting cooling time is extracted from the initial setting cooling index and recorded as ,Will As the control cooling time, record it as ,Will As a control cooling indicator, To set the reference temperature distribution difference.

[0087] It should be added that The specific value can be 5℃.

[0088] R3, when When the initial setting cooling wind speed is extracted from the initial setting cooling index, it is recorded as ,Will As the control cooling wind speed, denoted as ,Will and As a control cooling indicator.

[0089] R4, if ,when When the initial setting cooling mode is extracted from the initial setting cooling index, if the initial setting cooling mode is stage cooling, As a control cooling indicator, if it is not stage cooling, the stage cooling and As a control cooling indicator.

[0090] R5. When If the initial setting of cooling mode is stage cooling, confirm the number of controlled cooling stages, recorded as ,Will , and As a control cooling indicator, if it is not stage cooling, stage cooling, , and As a control cooling indicator.

[0091] Among them, confirm the number of cooling stages to control, including: R51, the number of cooling stages set from the initial setting cooling index .

[0092] R52, calculate the number of controlled cooling stages , .

[0093] Understandably, , ,in, and They represent the cooling wind speed correction factor and the cooling stage number correction factor respectively. They are mainly set with reference to the Sigmoid function to ensure that the correction factor range is between 0 and 1, and minus 0.5 is when , the cooling wind speed correction is in a critical state. The value is 0.5, so 0.5 is subtracted to avoid overcorrection. and , the correction factor of the number of cooling stages is in a critical state. Similarly, 0.5 is subtracted to adjust the correction factor to improve the effectiveness of the correction.

[0094] It should be added that the cooling process is one of the important links in the production of quartz crucibles, and the appropriate cooling speed is crucial to the quality of the final product. The control of the cooling equipment needs to match the speed of the conveying equipment to ensure that the product is gradually cooled under optimal conditions. Therefore, it is necessary to combine the conveying parameters of the conveying equipment and the sintering parameters of the sintering equipment to control the cooling parameters of the cooling equipment.

[0095] It should also be added that when the sintering process deviates significantly from the ideal sintering state, the temperature distribution of each area can be better controlled by performing segmented cooling, thereby ensuring that the quartz crucible cools down evenly during the cooling process. This can reduce stress concentration caused by local temperature differences, avoid cracking and other problems, and enable the material to release internal stress in an optimal way at different stages, thereby improving the strength and stability of the final product.

[0096] When confirming the control cooling index of the cooling equipment, the embodiment of the present invention controls the cooling time, cooling mode, cooling wind speed and other aspects by combining the temperature distribution difference of the sintered finished product, thereby greatly improving the uniformity of cooling, thereby reducing the internal stress caused by uneven cooling, thereby improving product quality, and at the same time making the cooling process more efficient and stable, avoiding local overcooling or overheating, and ensuring the stability of the physical and chemical properties of the product.

[0097] The database is used to store the appropriate atmosphere pressure of the quartz crucible at each sintering stage, and to store the reference temperature change curve of the quartz crucible at each sintering stage.

[0098] See also Figure 2 As shown, the equipment central control terminal includes a sintering equipment control unit, a conveying equipment control unit and a cooling equipment control unit, which are used to correspondingly control the operation of the sintering equipment, the conveying equipment and the cooling equipment through PLC.

[0099] Specifically, the corresponding control of the operation of the sintering equipment includes but is not limited to sending sintering indicators, such as sintering temperature and sintering time, etc. The corresponding control of the operation of the conveying equipment includes but is not limited to sending control conveying indicators to the conveying equipment when the conveying equipment needs to be adjusted, and controlling the conveying equipment to perform corresponding conveying; the corresponding control of the operation of the cooling equipment includes but is not limited to sending control cooling indicators to the cooling equipment when the cooling equipment needs to be adjusted, and controlling the cooling conveying equipment to perform corresponding cooling.

[0100] The embodiment of the present invention monitors the sintering process of the sintering equipment and performs control analysis of the conveying equipment and the cooling equipment according to the monitoring results, thereby realizing the linkage analysis of multiple processes in the production process of the quartz crucible, solving the problem of weak linkage in the current production control of the quartz crucible, avoiding the shortcomings of the current single control object, and thus facilitating the guarantee of continuity and stability in the production process of the quartz crucible.

[0101] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they shall all fall within the protection scope of the present invention.

Claims

1. A multi-process equipment control system for quartz crucible production based on PLC control, characterized in that: The system includes: The sintering equipment monitoring module is used to monitor the sintering temperature and atmosphere pressure of the quartz crucible at each sintering stage during the sintering process, corresponding to each sintering time point, and the sintering state information of the sintered product after the sintering equipment completes sintering, to form a sintering data set; A conveying equipment control module is used to import the initial conveying setting index of the conveying equipment, and judge the control demand of the conveying equipment based on the sintering data set. If the judgment result is that the control is required, the control conveying index of the conveying equipment is confirmed. If the judgment result is that no control is required, the initial conveying setting index is used as the control conveying index, and the conveying equipment is started for conveying; The cooling equipment control module is used to import the initial setting cooling index of the cooling equipment, and judge the cooling control demand of the cooling equipment based on the control transmission index of the transmission equipment and the sintering data set. If the judgment result is the demand control, the control cooling index of the cooling equipment is confirmed. If the judgment result is that no control is required, the initial setting cooling index is used as the control cooling index, and the cooling equipment is started for cooling; A database for storing the appropriate atmosphere pressure of the quartz crucible at each sintering stage and storing the reference temperature change curve of the quartz crucible at each sintering stage; The equipment central control terminal includes a sintering equipment control unit, a conveying equipment control unit and a cooling equipment control unit, which are used to control the operation of the sintering equipment, the conveying equipment and the cooling equipment through PLC; The determining of the demand for transmission equipment regulation includes: With the sintering time point as the horizontal axis and the sintering temperature as the vertical axis, the monitoring temperature change curve of each sintering stage is drawn. At the same time, the reference temperature change curve of the quartz crucible in each sintering stage during the sintering process is extracted from the database, and the sintering temperature change consistency is calculated, which is recorded as ; The standard deviation of the atmosphere pressure corresponding to each sintering time point in the same sintering stage is calculated, and the calculation result is used as the atmosphere pressure deviation degree; The atmosphere pressure corresponding to each sintering time point in the same sintering stage is averaged and calculated to obtain the average atmosphere pressure corresponding to each sintering stage, and the appropriate atmosphere pressure of the quartz crucible in each sintering stage is extracted from the database; The atmosphere pressure deviation, average atmosphere pressure and suitable atmosphere pressure at each sintering stage are recorded as , and , Indicates the sintering stage number, ; Calculate the consistency of sintering atmosphere pressure change, denoted as , , To set the reference atmosphere pressure difference, is the number of sintering stages; The monitoring values ​​and infrared thermal images of each sintering defect monitoring index are extracted from the sintering state information, and the number of temperature distribution areas and the temperature values ​​corresponding to each temperature distribution area are extracted from the infrared thermal images. The consistency of the sintering product state change is calculated and recorded as ; like , and If there is an item in the table that is less than the corresponding reference value, the demand control is used as the judgment result. , and If both are greater than or equal to the set reference value, no regulation is required as a judgment result; The calculation of the sintering temperature variation consistency includes: Set the temperature change matching evaluation factor for each sintering stage, denoted as ; The monitored temperature change curve of each sintering stage is overlapped and compared with the corresponding reference temperature change curve to obtain the overlap curve length, which is recorded as , the length of the monitoring temperature change curve at each sintering stage is recorded as ,Will As the temperature variation overlap ratio of each sintering stage; The sintering stages whose temperature change coincidence ratio is greater than the set reference temperature change coincidence ratio are recorded as coincidence stages, the number of coincidence stages is counted, and the ratio of the number of coincidence stages to the number of sintering stages is recorded as the sintering temperature change coincidence degree; The temperature variation matching evaluation factor of each sintering stage is set, including: For each sintering stage, the slope, amplitude and number of fluctuation points of the monitoring temperature change curve and the reference temperature change curve are statistically analyzed; The slope, amplitude and number of fluctuation points of the monitored temperature change curve are used as each monitoring comparison item, and the slope, amplitude and number of fluctuation points of the reference temperature change curve are used as each reference comparison item, and each monitoring comparison item and each reference comparison item are compared one by one; If the difference between a monitoring comparison item and the corresponding reference item is within the set allowable range, the monitoring comparison item is recorded as a matching item, otherwise the monitoring comparison item is recorded as a deviation item, and the number of matching items in each sintering stage is counted; If the number of coincident items in a sintering stage is 3, 0 is used as the temperature variation coincidence evaluation factor of the sintering stage, otherwise, the sintering stage is recorded as a deviation stage; The number of coincidence items in the deviation phase is recorded as , and the difference between each deviation term and the corresponding reference term in the deviation phase is recorded as , Indicates Deviation terms, ; Set the temperature change coincidence evaluation factor in the deviation stage, denoted as , , and They represent the weight of the number of matching items in the deviation stage and the weight of the difference between each deviation item and the corresponding reference item in the deviation stage, To set the The reference deviation value of the deviation item, , represents the number of deviation terms, ; The calculation of the consistency of the state change of the sintered finished product includes: Comparing the monitoring value of each sintering defect monitoring index with the reference monitoring value set for each sintering defect monitoring index; The sintering defect monitoring index whose monitoring value is greater than or equal to the reference monitoring value is marked as the confirmed defect index, the number of confirmed defect indexes is counted, and the ratio of the number of confirmed defect indexes to the number of sintering defect monitoring indexes is taken as the defect ratio, recorded as ; The highest temperature value and the lowest temperature value are selected from the temperature values ​​corresponding to each temperature distribution area, and the difference between the two is recorded as the temperature difference, and the temperature difference and the number of temperature distribution areas are recorded as and ; Calculate the consistency of the state change of the sintered finished product , , , and They are respectively expressed as the weights corresponding to the defect ratio, temperature difference and number of temperature distribution areas, , and They represent the defect ratio, temperature difference and number of temperature distribution areas of the set reference respectively. ; The control transmission index of the confirmation transmission device includes: Traversal , and , and set the overall deviation factor of the sintering state, recorded as ; The initial transmission speed and the set transmission speed control interval are extracted from the initial transmission setting index, and the lower limits of the initial transmission speed and the set transmission speed control interval are recorded as and ; Calculate and confirm the control transmission speed of the transmission equipment , ,Will As a control transmission indicator for transmission equipment; The setting of the overall deviation factor of the sintering state includes: Will , and The items that are smaller than the corresponding reference values ​​are recorded as missing items, and the number of missing items is counted and recorded as ; Calculate separately , and The difference between the set corresponding reference value is recorded as , and ; Set the overall deviation factor of the sintering state , ； The cooling equipment cooling control demand determination includes: Extraction of the overall deviation factor of the sintering state ; like , and the judgment result is that no regulation is needed; If the overall deviation factor of the sintering state Greater than or equal to the set reference sintering state overall deviation factor , then demand regulation is used as the judgment result; like , compare the control transmission speed of the transmission device with its initial transmission speed, and use the ratio as the transmission speed reduction ratio, recorded as ; The initial transmission time of the sintering equipment and cooling equipment is extracted from the initial transmission setting index and recorded as ,Will As the increase in cooling time, record it as ; calculate and The difference is taken as the sintering deviation difference, and is matched and compared with the set reference increase cooling time to obtain the matching reference increase cooling time, which is recorded as ; like , the judgment result is that no regulation is needed, otherwise the judgment result is that regulation is needed.

2. The multi-process equipment control system for producing quartz crucibles based on PLC control as claimed in claim 1, characterized in that: The step of confirming the cooling control index of the cooling device includes: The standard deviation of the temperature values ​​corresponding to each temperature distribution area is calculated, and the calculation result is used as the temperature distribution difference of the sintered product, recorded as ; like ,when When , the initial setting cooling time is extracted from the initial setting cooling index and recorded as ,Will As the control cooling time, record it as ,Will As a control cooling indicator, To set the reference temperature distribution difference; when When the initial setting cooling wind speed is extracted from the initial setting cooling index, it is recorded as ,Will As the control cooling wind speed, denoted as ,Will and As a control cooling indicator; like ,when When the initial setting cooling mode is extracted from the initial setting cooling index, if the initial setting cooling mode is stage cooling, As a control cooling indicator, if it is not stage cooling, the stage cooling and As a control cooling indicator; when If the initial setting of cooling mode is stage cooling, confirm the number of controlled cooling stages, recorded as ,Will , and As a control cooling indicator, if it is not stage cooling, stage cooling, , and As a control cooling indicator.

3. The multi-process equipment control system for producing quartz crucibles based on PLC control as claimed in claim 2, characterized in that: The confirmation and control of the number of cooling stages include: Extract the number of setup cooling stages from the initial setup cooling index ; Calculation of the number of controlled cooling stages , .

Images