Analysis of advantages and disadvantages of external vacuum heat treatment furnace

What are the advantages and disadvantages of the external vacuum heat treatment furnace? Zhengzhou Kejia Electric Furnace Co., Ltd. will share with you:
The advantages of external vacuum heat treatment furnace mainly include:
1. The structure is simple and easy to construct, or the original ordinary heat treatment resistance furnace is modified;
2. The volume of vacuum chamber is small and the exhaust volume is small. There are few other components that need to be degassed except the working parts in the furnace, so the exhaust volume is small (no heat shield structure, etc.) and it is easy to achieve high vacuum;
3. Since the electric heating element is heated externally, there is no vacuum discharge problem;
4. The furnace has no more mechanical program action, simple operation, few faults and convenient maintenance;
5. The workpiece of the high-temperature vacuum furnace is not in contact with the furnace lining, and there is no possibility of chemical reaction under high temperature;
6. Compared with the internal heated vacuum furnace, the cost is only 1 / 2-1 / 3 of the internal heated vacuum furnace under the same loading capacity due to its simple structure; It is more practical in terms of maintenance, service life and reliability.

But at the same time, there are still some defects in the external heat type vacuum heat treatment furnace, mainly including:
1. The heat transfer efficiency of the furnace is low and the workpiece heating speed is slow;
2. Due to the limitation of furnace material, the working temperature of the furnace is generally maintained within the range of less than 1000-1000 ℃;
3. Part of the furnace tank is exposed to the atmosphere. Although the heat shield can be set, the heat loss is still large;
4. The heat capacity and thermal inertia of the furnace are very large and it is difficult to control;
5. The service life of the furnace tank is short.