Vapour phase vacuum drying plant (VPD)

Limra-VDP Product

Vacuum drying plant is basically designed for De-moisturizing the paper insulated coils, wingdings, core and bushings of transformers. As a standard practice in manufacturing of transformers removal of moisture is necessary.

Advantage of vacuum drying compare to atmospheric drying is fast & secure process. In ambient temperature water boils at 100 0 C, where in vacuum it boils at 60 0 C. Shape & size of the autoclave is depend upon the size of job and the mass of insulation present. It may rectangular or cylindrical in shape with eighter single or double door provision. Job can be load by front or top loading as per customers requirement

Door & Trolley Arrangement:

Door & job transfer trolley movements can be manual or motorised, Door clamping & rail bridge assembly can be hydraulically operated.

Heating System:

Heating system for VDP may possible by thermic fluid oil, electric heaters, gas or by steam. In our system we use high vacuum low heating concept. Due to controlled, low and gradual uniform heating HV / LV coils dried healthy. There is no chance of deterioration. Cellulose fiber get released moisture and evacuated by vacuum system.

Vacuum – Pumping system:

Primary and secondary condenser will condense hot vapour & release condensate water. for condensation, properly designed chilling plant & condensers are provided in vacuum system. Roots and Rotary vacuum pump combination are provided as per requirement. During vacuum drying process various temperature/vacuum parameters can be seen on control panel. You can also measure the megger values during process

The job temp, megger values and condensate will come to conclude the end of process cycle.

We do provision of oil filling systems under vacuum to avoid atmospheric exposure at the end of process. For effective dryness of huge size transformer, we provide scavenging system, we can do pressure heating with safe dry vacuum break.

Services we Provide

Conversion of VDP ( Vacuum drying plant ) into VPD (Vapour phase drying plant)

Refurbishment of existing plants

Automization of plants

Up-gradation of plants