How to operate vacuum sintering furnace safely?

Vacuum sintering furnace is a furnace that uses induction heating to conduct protective sintering of heated articles. It can be divided into power frequency, medium frequency, high frequency and other types, which can be classified as a subclass of vacuum sintering furnace. Vacuum induction sintering furnace is a complete set of equipment that uses the principle of medium frequency induction heating to sinter cemented carbide cutter heads and various metal powder compacts under vacuum or protective atmosphere. It is designed for the industrial production of cemented carbide, dysprosium metal and ceramic materials.

So, how can we safely operate the vacuum sintering furnace?

1. The cooling water source of medium frequency power supply, vacuum furnace body and induction coil - the water in the reservoir must be full and free of impurities. Vacuum furnace

2. Start the water pump to make its medium frequency power supply, vacuum furnace induction coil and furnace body cooling system circulate normally, and adjust the water pressure to control it at the specified value.

3. Check the power supply system of the vacuum pump, the tightness of the belt pulley, and whether the vacuum pump oil is located at the centerline of the oil seal observation hole. After checking, manually rotate the vacuum pump pulley. 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 is sanitary, the induction ring is well insulated, the sealing vacuum tape is elastic, and the size is qualified.

5. Check whether the lever handle of the vacuum furnace can be started flexibly.

6. Check whether the rotary McDonnell vacuum gauge meets the requirements.

7. Check whether the graphite crucible and charging accessories are complete.

8. After the above preparations are ready, turn on the power supply, switch on the intermediate frequency power supply, start the frequency conversion according to the intermediate frequency starting rules, and stop the frequency conversion after success before starting the furnace.

9. The observation and temperature measurement holes on the upper cover of the vacuum furnace shall be cleaned every time the furnace is opened for observation and temperature measurement.

10. During charging, corresponding charging methods shall be adopted according to different sintered products. The plate shall be installed according to the furnace loading 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. Place the vacuum sealing tape.

13. Operate the lever handle, rotate the vacuum furnace top cover to closely coincide with the furnace body, put down the top cover, and lock the fixing nut.

14. Slowly open the butterfly valve and extract air from the furnace until the vacuum reaches the specified value.

15. After the vacuum degree reaches the specified requirements, start the frequency conversion, adjust the medium frequency power, and operate according to the sintering regulations of relevant materials; Temperature rise, thermal insulation and cooling.

16. After the sintering is completed, stop the frequency conversion, press the stop frequency conversion switch, the inverter stops working, and disconnect the intermediate frequency power switch and the main power switch.

17. After observing the furnace blackening from the furnace body observation hole, first close the vacuum pump butterfly valve and disconnect the vacuum pump current, then connect the tap water to continue cooling the induction coil and furnace body, and finally stop the water pump.

18. If the medium frequency voltage is 750 V, there is a danger of electric shock. During the whole operation and inspection process, pay attention to the operation safety, and do not touch the intermediate frequency electrical cabinet with your hands.

19. During the sintering process, observe whether the induction coil is arcing from the observation hole on the side of the furnace at any time. If any abnormal phenomenon is found, report it to the relevant personnel immediately for handling.

20. The vacuum butterfly valve shall be started slowly, otherwise, oil will flow out due to too fast air extraction, which will lead to adverse consequences.

21. Correctly use the rotary McDonnell vacuum gauge, otherwise it will cause vacuum reading error or mercury overflow due to too fast operation, causing public hazards.

22. Pay attention to the safe operation of the vacuum pump pulley.

23. When padding vacuum sealing tape and covering the furnace top cover, pay attention to prevent hand pressing.

24. Workpieces or containers that are easy to volatilize under vacuum conditions and affect vacuum sanitation, causing pipe blockage and vacuum pump fouling shall not be put into the furnace.

25. All products with molding agent (such as oil or paraffin) must be removed before being put into 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 the circulation of cooling water to avoid accidents.