CN-121992480-A - Potassium titanyl phosphate crystal growth furnace and control method thereof

CN121992480ACN 121992480 ACN121992480 ACN 121992480ACN-121992480-A

Abstract

The invention belongs to the technical field of crystal growth, and particularly discloses a potassium titanyl phosphate crystal growth furnace and a control method thereof, wherein the method comprises the steps of driving a seed crystal rotating rod through a direct current motor to realize constant rotation, dynamically correcting the perpendicularity of the seed crystal rotating rod through a ball structure in a connecting seat, realizing accurate lifting of the seed crystal rotating rod by utilizing a gear meshing transmission function and a screw rod adjusting function in a lifting device, monitoring temperature distribution in a furnace barrel in real time through a temperature sensor, combining a PLC control system and adjusting heating power based on a PID algorithm to maintain solution uniformity, adjusting the rotating speed of the direct current motor according to a voltage signal output by a potentiometer, and ensuring that the rotating speed of the seed crystal rotating rod is matched with the lifting speed.

Inventors

YU JIE
XIONG YUANYUAN
XU XUHUI

Assignees

昆明理工大学

Dates

Publication Date: 20260508
Application Date: 20260305

Claims (10)

1. A control method of a potassium titanyl phosphate crystal growth furnace is characterized by comprising the following steps: The seed crystal rotating rod is driven by the direct current motor to realize constant rotation, and the perpendicularity of the seed crystal rotating rod is dynamically corrected by a ball structure in the connecting seat; the precise lifting of the seed crystal rotating rod is realized by utilizing the gear meshing transmission and screw rod adjusting functions in the lifting device; The temperature distribution in the furnace barrel is monitored in real time through a temperature sensor, and the heating power is adjusted based on a PID algorithm by combining a PLC control system so as to maintain the uniformity of the solution; The rotating speed of the direct current motor is regulated according to the voltage signal output by the potentiometer, so that the rotating speed of the seed crystal rotating rod is ensured to be matched with the pulling rate; displaying current technological parameters through a liquid crystal display and recording key data; The platinum crucible is arranged between the multi-layer heat insulation materials, and the temperature gradient control is realized through heating by the electric furnace wire; And finally generating a complete crystal growth log for subsequent analysis and optimization.
2. The method for controlling a crystal growth furnace of potassium titanyl phosphate as set forth in claim 1, wherein the step of driving the seed crystal spin lever to achieve constant rotation by the DC motor and dynamically correcting the perpendicularity of the seed crystal spin lever by the ball structure in the connecting seat comprises: The direct current motor is fixed on a cross arm of the machine body, the seed crystal rotating rod is clamped through an upper connecting block and a lower connecting block in the connecting seat, and a plurality of balls are embedded in the connecting seat to reduce friction force; An adjusting bolt is penetrated in the through holes of the upper connecting block and the lower connecting block, and the clamping force of the connecting seat on the seed crystal rotating rod is changed through the tightness degree of the adjusting bolt; after the direct current motor is started, the seed crystal rotating rod keeps stable rotation under the support of the balls, and meanwhile, the ball structure dynamically compensates the radial offset of the seed crystal rotating rod; And if the verticality deviation of the seed crystal rotating rod exceeds a preset threshold value, the position of the seed crystal rotating rod is corrected again through the adjusting bolt.
3. The method for controlling a crystal growth furnace of potassium titanyl phosphate as set forth in claim 1, wherein the step of precisely pulling the seed crystal spin-rod by utilizing the gear engagement transmission and screw adjustment functions of the pulling device comprises the steps of: two gears are respectively arranged on the screw rod and the mechanical rocking handle, and the two gears realize synchronous motion through meshing transmission; the external surface of the screw is provided with standard threads, the cross arm is provided with a screw hole matched with the threads of the screw, and the cross arm is screwed with the screw through the screw hole; when the mechanical rocking handle is rotated, the screw rod moves along the axial direction to drive the cross arm to move up and down, so that the lifting of the seed crystal rotating rod is realized; The pulling rate is determined by the gear ratio design of the gears, and if the pulling rate needs to be adjusted, gears with different gear ratios are replaced or the rotating speed of the mechanical rocking handle is changed.
4. The method for controlling a crystal growth furnace of titanyl potassium phosphate according to claim 1, wherein the step of monitoring the temperature distribution in the furnace barrel in real time by a temperature sensor, combining a PLC control system and adjusting the heating power based on a PID algorithm to maintain the uniformity of the solution comprises the steps of: The temperature sensor is arranged in the furnace barrel and close to the platinum crucible, and temperature data in the furnace barrel are collected in real time; Transmitting the acquired temperature data to a PLC control system, and calculating the heating power requirement by the PLC control system according to a preset temperature curve; The platinum crucible is heated by the electric furnace wire, and the input power of the electric furnace wire is regulated by the PLC control system; if the temperature detected by the temperature sensor deviates from the preset range, the PLC control system automatically adjusts the heating power of the electric stove wire.
5. The method for controlling a crystal growth furnace of potassium titanyl phosphate according to claim 1, wherein the step of adjusting the rotational speed of the DC motor according to the voltage signal output from the potentiometer to ensure that the rotational speed of the seed crystal rotating rod matches the pulling rate comprises the steps of: the potentiometer is electrically connected with the direct current motor, and the output voltage is changed by rotating a potentiometer knob; the voltage signal output by the potentiometer is transmitted to the direct current motor after being processed by the amplifying circuit, and the rotating speed of the direct current motor is controlled; the liquid crystal display is electrically connected with the potentiometer, and displays the voltage value output by the potentiometer and the actual rotating speed of the direct current motor in real time; If the rotation speed of the seed crystal rotating rod is not matched with the lifting speed, the rotation speed of the direct current motor is changed by adjusting the potentiometer knob.
6. The method for controlling a crystal growth furnace of potassium titanyl phosphate as set forth in claim 1, wherein the step of displaying current process parameters and recording key data via a liquid crystal display comprises: The liquid crystal display is arranged on the machine body and is electrically connected with the PLC control system; the liquid crystal display displays temperature data acquired by the temperature sensor, voltage signals output by the potentiometer, the rotating speed of the direct current motor and the pulling rate of the pulling device in real time; The PLC control system stores the data displayed by the liquid crystal display into the built-in storage module to form a complete process parameter record; if the technological parameters exceed the preset range, the liquid crystal display gives an alarm prompt.
7. The method for controlling a crystal growth furnace of potassium titanyl phosphate according to claim 1, wherein the step of disposing the platinum crucible between the plurality of layers of insulating materials and heating the crucible by using an electric wire to control the temperature gradient comprises the steps of: The platinum crucible is horizontally arranged on a liftable bottom plate, and the bottom plate is connected with the machine body through a sliding rail; Sequentially wrapping a first heat-preserving material layer, an electric furnace wire and a second heat-preserving material layer on the periphery of a platinum crucible; The first heat-insulating material layer and the second heat-insulating material layer are made of high-temperature-resistant ceramic fiber materials, and the electric furnace wire is connected with the PLC control system through a power wire; And the PLC control system adjusts the heating power of the electric stove wire according to the signal fed back by the temperature sensor.
8. The method for controlling a crystal growth furnace of potassium titanyl phosphate according to claim 1, wherein the step of finally generating a complete crystal growth journal for subsequent analysis and optimization comprises the steps of: transmitting the process parameters recorded by the liquid crystal display to external storage equipment through a communication interface to form a crystal growth log; the crystal growth log comprises a temperature change curve, a direct current motor rotating speed record, lifting speed data and changes of potentiometer output voltage; by analyzing the crystal growth log, evaluating the temperature stability in the crystal growth process, the rotation precision of the seed crystal rotating rod and the matching degree of the pulling rate; if the crystal growth result does not reach the expected value, the process parameters are adjusted according to the data in the crystal growth log.
9. The method for controlling a crystal growth furnace of titanyl potassium phosphate according to claim 1, wherein the control method is realized by a crystal growth furnace control system of titanyl potassium phosphate, the system comprises: The rotation control module is configured to drive the seed crystal rotating rod to realize constant rotation through the direct current motor, and dynamically correct the perpendicularity of the seed crystal rotating rod through a ball structure in the connecting seat; the lifting adjusting module is configured to realize the accurate lifting of the seed crystal rotating rod by utilizing the gear meshing transmission and screw adjusting functions in the lifting device; The temperature management module is configured to monitor the temperature distribution in the furnace barrel in real time through a temperature sensor, and is combined with the PLC control system and adjusts the heating power based on a PID algorithm to maintain the uniformity of the solution; the rotating speed matching module is configured to adjust the rotating speed of the direct current motor according to the voltage signal output by the potentiometer, and ensure that the rotating speed of the seed crystal rotating rod is matched with the pulling rate; the data display module is configured to display the current process parameters through the liquid crystal display and record key data; The thermal environment optimization module is configured to be used for arranging the platinum crucible between the plurality of layers of heat insulation materials and realizing temperature gradient control through heating of the electric furnace wire; And the log generation module is configured to finally generate a complete crystal growth log for subsequent analysis and optimization steps.
10. A potassium titanyl phosphate crystal growing furnace, characterized by comprising a growing furnace body and a potassium titanyl phosphate crystal growing furnace control system according to claim 9, wherein the growing furnace body is used for realizing a potassium titanyl phosphate crystal growing furnace control method according to claims 1-8.

Description

Potassium titanyl phosphate crystal growth furnace and control method thereof Technical Field The invention relates to the technical field of crystal growth, in particular to a potassium titanyl phosphate crystal growth furnace and a control method thereof. Background In the growth process of potassium titanyl phosphate (KTiOPO 4, KTP for short), the core technical problem is how to realize the vertical precision control of a seed crystal rotating rod during the continuous rotation stirring of the crystal growth period, and simultaneously ensure the stability and the precision of the pulling process, and the problem relates to the selection of a flux system and the maintenance of the uniformity of a solution in a flux method, but the nucleation distribution is uneven due to the fact that the seed crystal is static relative to the solution, so that the crystal quality is affected. In addition, the KH2PO4-K2HPO4-TiO2 system has higher water content in a high-temperature environment, and liquid overflows easily due to evaporation, so that the operation complexity is increased. The application number is CN86100393 discloses a process and a device for growing potassium titanyl phosphate crystal by a fluxing agent method, KPO3 and K4P2O7 are adopted as fluxing agents, and the raw materials are melted by heating an electric furnace wire and then cooled for growth. However, the method does not provide specific vertical precision guarantee measures, and the seed crystal rotating rod is manually operated according to experience in the pulling process, so that the crystal growth condition is unstable possibly caused by human factors, and the crystal performance is further affected. Finally, in practical operation, the design and control of the pulling device has an important effect on the crystal growth result. If the pulling speed or the rotation precision cannot meet the requirement, uneven stress distribution or increased defects in the crystal may be caused, and meanwhile, the technical training requirement on operators further improves the threshold of process implementation. The comprehensive problem extends through the whole process from seed crystal placement, solution uniformity maintenance to crystal pulling, and relates to multiple interactions of mechanical design, temperature control and manual operation, and the growth efficiency and quality of KTP crystals are directly affected. Disclosure of Invention The invention provides a potassium titanyl phosphate crystal growth furnace and a control method thereof, and aims to solve the problems that in the prior art, the vertical precision of a seed crystal rotating rod is difficult to guarantee during crystal growth, the lifting process is unstable and the solution uniformity is difficult to maintain in a high-temperature environment. In order to solve the technical problems, the invention adopts the following technical scheme: A control method for the crystal growth furnace of potassium titanyl phosphate includes such steps as driving the rotary rod of seed crystal by DC motor, dynamically correcting the perpendicularity of rotary rod of seed crystal by ball structure in connecting seat, precisely lifting the rotary rod of seed crystal by the meshing drive of gears and regulating screw rod, real-time monitoring the temp distribution in furnace barrel by temp sensor, regulating heating power by PLC control system and PID algorithm, regulating the rotation speed of DC motor, regulating the rotation speed of rotary rod, displaying the current technological parameters by LCD, recording key data, heating Pt crucible between multi-layer insulating materials, and controlling the temp gradient by electric furnace wire. In one aspect of the disclosure, the step of driving the seed crystal rotating rod by the direct current motor to realize constant rotation and dynamically correcting the perpendicularity of the seed crystal rotating rod by the ball structure in the connecting seat includes: The direct current motor is fixed on a cross arm of the machine body, the seed crystal rotating rod is clamped through an upper connecting block and a lower connecting block in the connecting seat, and a plurality of balls are embedded in the connecting seat to reduce friction force; An adjusting bolt is penetrated in the through holes of the upper connecting block and the lower connecting block, and the clamping force of the connecting seat on the seed crystal rotating rod is changed through the tightness degree of the adjusting bolt; after the direct current motor is started, the seed crystal rotating rod keeps stable rotation under the support of the balls, and meanwhile, the ball structure dynamically compensates the radial offset of the seed crystal rotating rod; And if the verticality deviation of the seed crystal rotating rod exceeds a preset threshold value, the position of the seed crystal rotating rod is corrected again through the adjusting bolt. In one aspect of the dis