The characteristics of the vacuum furnace temperature field

The characteristics of the vacuum furnace temperature field

The heating element of a vacuum furnace is generally round. The heat transfer in a vacuum is only radiation, no conduction and convection. There are three modes of conduction, convection and radiation in non-vacuum heating, and the convection and conduction are different from normal furnace (conventional pressure).
The pressure is less than 1 x 105Pa (absolute pressure, the approximate work pressure of the normal furnace). Working pressure close to the vacuum (pa) 2, the convection and conduction effect basic does not exist, workpiece temperature is slow, especially below 600 ℃ heating, heating more slowly, the temperature of the workpiece temperature thermocouple temperature control has certain hysteresis.
The vacuum furnace temperature uniformity measurement is different from ordinary furnace, when measuring the need to guarantee the normal work of the furnace under the condition of vacuum and pressure rise rate, can correct determination of furnace temperature. Because, unlike ordinary furnace, vacuum furnace heat transfer of actual temperature measurement process shows that the control thermocouple temperature at the beginning of the heat preservation and the effective heating area measuring thermocouple temperature difference is bigger. In vacuum condition, temperature deviation in the normal heat preservation time of the effective heating area can reach + / - 5 ℃, meet the needs of the process.