On 2018-08-08 14:48:54
vacuum heat treatment furnace safe operation
Vacuum heat treatment furnace is a kind of furnace that uses induction heating to carry out protective sintering of heated articles. It can be divided into power frequency, medium frequency, high frequency and other types, which can be classified into sub categories of vacuum sintering furnace. The vacuum induction sintering furnace is a complete set of equipment, which uses the principle of medium frequency induction heating to realize the sintering of cemented carbide cutter head and various metal powder compacts under the condition of vacuum or protective atmosphere. It is designed for the industrial production of cemented carbide, dysprosium metal and ceramic materials.
1. The cooling water source of medium frequency power supply, vacuum furnace body and induction ring - the water in the reservoir must be full and free of impurities.
2. Start the water pump to make its medium frequency power supply, induction ring of vacuum furnace and cooling system of furnace body circulate normally, and adjust the water pressure to the specified value.
3. Check whether the power supply system of the vacuum pump, the belt of the belt pulley are loose, and whether the vacuum pump oil is located in the center line of the oil seal observation hole. After inspection, manually rotate the belt pulley of the vacuum pump. If there is no abnormality, start the vacuum pump with the butterfly valve closed.
4. Check the condition of the vacuum furnace body. It is required that the vacuum furnace body shall be first-class sanitary, the induction ring shall be well insulated, the sealing vacuum tape shall be elastic and the size shall be qualified.
5. Check whether the lever handle of the vacuum furnace body can be started flexibly.
6. Check whether the rotary type McIntosh vacuum gauge meets the requirements.
7. Check whether graphite crucible and furnace accessories are complete.
8. After the above preparations are completed, turn on the power supply, switch on the intermediate frequency power supply, and try to start the frequency conversion according to the intermediate frequency startup rules. The furnace can be started only after the frequency conversion is stopped successfully.
9. The observation and temperature measurement holes on the top cover of the vacuum furnace body shall be cleaned every time the furnace is opened for observation and temperature measurement.
10. When charging, the corresponding charging method shall be adopted according to different sintering products. The plates shall be installed according to the charging rules of relevant materials and shall not be changed at will.
11. In order to maintain constant temperature and prevent thermal radiation, two layers of carbon fiber are added to the heating crucible, and then the heat shield is covered.
12. Pad the vacuum sealing tape.
13. Operate the lever handle, rotate the top cover of the vacuum furnace to closely coincide with the furnace body, lower the top cover and lock the fixing nut.
14. Open the butterfly valve and extract the air from the furnace until the vacuum degree reaches the specified value.
15. After the vacuum degree reaches the specified requirements, start the frequency conversion, adjust the intermediate frequency power, operate according to the sintering regulations of relevant materials; heat up, heat preservation and cooling.
16. After sintering, stop the frequency conversion, press the stop frequency conversion switch, the inverter stops working, and disconnect the if power supply and the main power supply.
17. Turn off the butterfly valve of vacuum pump and disconnect the current of vacuum pump, connect the tap water to continue cooling the induction ring and furnace body, and finally stop the water pump.
18. If voltage is 750 V, there is danger of electric shock. During the whole operation and inspection process, pay attention to the operation safety, and do not touch the intermediate frequency electric cabinet by hand.
19. During the sintering process, observe whether the induction ring is arcing from the observation hole on the side of the furnace body at any time. If any abnormal phenomenon is found, it shall be reported to the relevant personnel for handling immediately.
20. Start the vacuum butterfly valve slowly, otherwise it will emit oil due to the over pumping, resulting in adverse consequences.
21. Use the rotating Macintosh vacuum gauge correctly, otherwise it will cause the error of vacuum reading or the mercury overflow caused by the operation too fast.
22. Pay attention to the safe operation of the vacuum pump pulley.
23. When the vacuum sealing tape is padded and the top cover of the furnace body is covered, pay attention to prevent the pressing hand.
24. The workpieces or containers that are easy to volatilize and affect the vacuum sanitation under vacuum conditions, causing pipe blockage and vacuum pump dirtiness, shall not be put into the furnace.
25. If the product is added with molding agent (such as oil or paraffin), it must be removed before entering the furnace for sintering, otherwise it will cause adverse consequences.
26. During the whole sintering process, pay attention to the pressure range of water meter and cooling water circulation to avoid accidents.