Motor Windings Varnish Vacuum Pressure Impregnation Equipment Max Dia 5000 mm

1. Applications 

The VPI series vacuum varnish impregnation machine impregnates the workpieces in a sealed tank

under a certain pressure,which forces the impregnant to immerse more completely into the gaps of the

workpieces. The vacuum impregnation process equipment is specially used for impregnation of windings of

high voltage motors, traction motors, special motors, anti explosion pump motors, magnetic motors,

and transformers. The windings after impregnation in VPI equipment have an improved insulation performance,

a reduced surface temperature, an improved mechanical strength, a reduced fault rate, a better anti-moisture

capacity, and a long service life.

2. Features 

The impregnating tank cover is opened and closed with the help of a hydraulic mechanism. The signal is

feedback through non-contact proximity switch. The tank cover opening angle follows the rule that the top

point of the opened cover passes over the inner wall of the impregnating tank.

The impregnating tank is equipped with a level transmitter.

The impregnating tank is equipped with an over-pressure alarm, and a pressure safety device.

The impregnating tank is designed with one anti-explosion peephole light and one observation window.

The impregnating tank of the vacuum pressure impregnation equipment is sealed by a silicon rubber ring.

When the impregnating tank cover is opened, the tank has safety interlock mechanism.

The impregnating tank is a vertical type.

The impregnation tank is equipped with a infrared camera so as to check the working performance of the tank.

3. Process flow of vacuum pressure impregnation process:

VPI process flow: pre drying and dehumidification → entering the impregnating tank → vacuum suction →

vacuum impregnation → pressure impregnation → resin retrun → pressure relieft and resin dripping→

parts out of the vacuum impregnation tank → curing and drying

4. Technical Parameters

Note: PLC automatic control. The equipment is in the vertical type. Horizontal type can also be supplied

if thus requested by the customer

5.Process application of vacuum pressure impregnation process (VPI) for motors

Comparison: obviously, VPI is far superior to other dipping and impregnating processes in terms of resin

penetration and impregnation. It is suitable for large windings, multi-layer windings and other applications with

high voltage winding requirements. In theory, the application of VPI, vacuum and pressure can be done quite

high, of course, the cost is also high. In the application experiment and practical work, it is found that the

vacuum environment can produce a large number of bubbles and a large amount of liquid mist in the impregnating

varnish when a vacuum impregnating varnish at a certain temperature condition reaches a corresponding "critical"

vacuum when the vacuum is below a certain absolute pressure value. That is, the phenomenon of "foaming" and

"atomization" occurs. "Foaming" causes a large number of holes in theresinsolution, which will hinder the infiltration.

"Atomization" causes a large amount of solvent or diluent to escape, which will affect the curing. In principle,

pressurization is to make theresinliquid easier to enter the filling gap. In fact, there is an atmospheric pressure

in theresinconveying process. If the wettability of the capillary in the insulating structure has been balanced,

increasing the pressure has no obvious effect on the filling of the whole insulating structure, unless the increased

pressure is maintained during curing. Therefore, the effective way to increase the filling is to reduce the viscosity

of the resin, reduce the gap of the insulating structure and improve the capillary effect, rather than increasing the

pressure. According to the test of "viscosity and pressure on penetration rate", the data show that when the viscosity

ofresinsolution is large, increasing the pressure has a great effect on the filling speed, and when the viscosity of resin solution

is small, the effect of increasing the pressure on the filling speed is not significant. However, the viscosity ofresinsolution

has a very significant impact on the filling speed, which is inversely proportional. It can be seen that in the application of

VPI process, it is blind and useless to emphasize and simply pursue high vacuum or high pressure. The result will affect

the impregnation efficiency and even destroy the impregnation quality.