This kind of furnace adopts variable-pressure drying principle suggested by Dr. Moll from Germany, specialized for drying transformer and power capacitor bodies. Comparing to conventional vacuum heating drying method, drying duration of this variable-pressure type has been saved about 30-45%.

Application of variable-pressure vacuum drying equipment:
- Drying transformer bodies in grade 10~110kV, capacity less than 100,000kVA
- Drying transformer windings in 110~500kV grade
- Drying current transformer and potential transformer bodies in 110~500kV grade
- Drying power capacitors
- Drying other electrical materials

Main features of variable-pressure vacuum drying equipment:
- Compact structure, small occupation
- High productivity: when drying one 110kV, 40000KVA transformer body, it will take only about 50 hours, close to that by kerosene vapor-phase drying equipment
- Heating system is controlled by power control module, assuring even and stable temperature; Real power consumption during temperature-keeping is only about 35% of total power; There is no fluctuation of heating load and thus reduces actual heating power very much.
- PLC control, high automation, more stable and reliable
- Special baffle valves for vacuum drying, better vacuuming performance

Specifications of variable-pressure vacuum drying equipment:
1) Vacuum drying tank
●Tank size: according to requirement
●Ultimate vacuity:<50Pa (unloaded, cold)
●Tank leakage: 300Pa•L/S
●Heating temperature: 130℃
●Temperature tolerance: ±2℃
2) Vacuum system
●Ultimate vacuity: ＜10Pa (unloaded, cold)
●Max. extracting speed: 900L/S
●Adopts low-temperature condenser, better condensing result, shorter drying duration
3) Heating system: electric heating, power 96kW, heating oil media
4) Water-cooling system: can be cooling tower or special water cooler
5) Control system: Siemens PLC control, automatic controlling vacuity, heating and cooling.