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

II Main features of variable-pressure vacuum drying equipment for transformers:

1) Compact structure, small occupation

2) 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.

3) PLC control, more stable and reliable

4) Special baffle valves for vacuum drying, better vacuuming performance
vacuum drying equipment

III Buildup of variable-pressure vacuum drying equipment for transformers:

3.1 Vacuum drying tank: square shape, one

3.2 Vacuum system: one

3.3 Low-temperature condensation filter

3.4 Heating system: one

3.5 Water-cooling system: one

3.6 Compressed air system: one

3.7 Electric control system

IV Main technical data of one typical variable-pressure vacuumn drying equipment for transformers:

Item		Data
Vacuum drying autoclave
1)	Effective inner dimension	2000 x 2000 x 3000mm (L x W x H)
2)	Ultimate vacuity	< 50Pa (idle, cold)
3)	Leakage of autoclave	< 300Pa·L/S
4)	Max. heating temperature	130℃
5)	Temperature evenness inside	±2℃
6)	Max. loading capacity	50T
7)	Temperature sensor	3 units
Vacuum system
1)	Ultimate vacuity	< 10Pa (idle, cold)
2)	Max. extracting speed	900L/S
3)	SV-300 rotary vacuum pump	1 unit
4)	ZJ900 Roots pump	1 unit
Heating power		96kW
Heating media		Heat induction oil
Control system
1)	Temperature displaying meter	3 units
2)	Temperature control meter	1 unit
3)	Vacuum transmitter	1 unit
4)	PLC + HMI	Siemens