Maintenance of high - temperature electric furnaces is crucial for prolonging their service life and ensuring safe operation. Here are some key maintenance points:

1.Regular inspection

Regularly check whether the electrical connections in the temperature control system are in good contact, paying special attention to whether the connection points of the heating elements are tightened. At the same time, check whether the pointer of the indicator has any jamming or stagnation during movement, and use a potentiometer to calibrate the increased error of the instrument caused by fatigue, balance destruction, etc. of the magnetic steel, demagnetization, expansion wire, and spring piece.

2.Keep clean

Keep the furnace chamber clean frequently and remove impurities such as oxides in the furnace in a timely manner. The inside and outside of the box should be kept clean. If it is not used for a long time, apply neutral grease or vaseline on the electroplated parts to prevent corrosion, and put on a plastic dust cover on the outside and place it in a dry room.

3.Avoid sudden changes in temperature

To avoid cracks in the furnace chamber during the high - and low - temperature change process, sudden changes in temperature should be avoided. Do not open the furnace door for a long time at high temperature, and it is prohibited to pour liquids into the furnace chamber and sinter items with high water content, which will shorten the service life of the furnace chamber and heating elements. Do not suddenly pull out the thermocouple at high temperature to prevent the outer casing from cracking.

4.Restart after shutdown

When the box - type furnace is used for the first time or used again after being out of service for a long time, it must be dried. The drying time should be four hours from room temperature to 200 °C, and four hours from 200 °C to 600 °C. When in use, the furnace temperature should not exceed the rated temperature to avoid burning out the electric heating elements. It is prohibited to pour various liquids and easily soluble metals into the furnace. When the muffle furnace works at a temperature below 50 °C, the furnace wire has a longer service life.

5.Controller temperature

The box - type furnace controller should be used within the ambient temperature range of - 10 - 75 °C. The box - type furnace and the controller must work in a place where the relative humidity does not exceed 85% and there are no conductive dust, explosive gas or corrosive gas. When heating metal materials with grease and the like attached, a large amount of volatile gas will affect and corrode the surface of the electric heating elements, causing them to be destroyed and shortening their service life. Therefore, prevention should be carried out in a timely manner during heating, and sealed containers should be made or appropriate holes should be opened for ventilation.

6.Special maintenance

If a large number of heating elements are damaged or the resistance value increases too much and the required furnace temperature cannot be reached, all of them should be replaced with new elements. During the working process, generally at about 200 - 300 °C, if the control deviation still cannot be eliminated and there is no temperature display value that does not match the program - given value or swings too much, please check whether the parameters are accurate.

7.Safety measures

High - temperature electric furnaces should be equipped with relevant safety facilities, such as safety valves, alarms, etc. During maintenance, check whether these facilities are working normally and whether they need to be replaced or repaired. At the same time, also check whether the protection equipment of the operators is complete to ensure the safety of the operation process.

The above points combine information from multiple sources to ensure comprehensiveness and accuracy of maintenance. When performing maintenance, always follow the manufacturer's instructions and suggestions to ensure the best performance and safe operation of the equipment.