Industrial Vacuum Impregnation Process for Motor Windings With
Drying Function
1. Application
The vacuum impregnation and drying machine employes a compound
process of “hot air-vacuum environment-hot air”, which enables the
windings to be impregnated and dried in a sealed container. The
vacuum
impregnation equipment has advantages of advanced design,
scientific process,
compact structure, easy operation, safety and reliability, good
sealing, and
reduced laboring strength. The vacuum impregnation process for
motor
windings is used for vacuum impregnation treatment of windings of
general motors, electrical equipment, special motors, pump motors,
magnetic motors, transformers, and iron cores. This vacuum varnish
impregnation machine is a newly energy-saving equipment, which
greatly
improves product quality, reduces production cost, and strengthens
competitiveness.
2. Technical Parameters
| Item | impregnating tank size (dia*height,mm) | working vacuum (Mpa) | impregnating tank working temperature ( degree celcius) | heater power (kw) | Total loading capacity (kw) | Approximate floor area (m2) |
| FGH-500 | 500×600 | 0.095 | AT-180 | 9 | 12 | 8.5 |
| FGH-700 | 700×800 | 0.095 | AT-180 | 9 | 12 | 10 |
| FGH-900 | 900×1000 | 0.095 | AT-180 | 13.5 | 16.5 | 12 |
| FGH-1200 | 1200×1300 | 0.095 | AT-180 | 18 | 21.5 | 18 |
| FGH-1400 | 1400×1500 | 0.095 | AT-180 | 22.5 | 26 | 22 |
| FGH-1600 | 1600×1700 | 0.095 | AT-180 | 27 | 32 | 28 |
| FGH-1800 | 1800×1900 | 0.095 | AT-180 | 36 | 43.5 | 30 |
| FGH-2000 | dia2000×2100 | 0.095 | AT-180 | 50 | 60 | 35 |
| FGH-2500 | 2500×2500 | 0.095 | AT-180 | 80 | 100 | 42 |
| FGH-3000 | 3000×2800 | 0.095 | AT-180 | 120 | 140 | 55 |
| FGH-3500 | 3500×3400 | 0.095 | AT-180 | 150 | 180 | 65 |
| FGH-4000 | 4000×3800 | 0.095 | AT-180 | 200 | 250 | 75 |
| FGH-5000 | 5000x4500 | 0.095 | AT-180 | 220 | 270 | 85 |
Note: AT refers to ambient temperature.
3. What is vacuum impregnation and drying process?
A process has different insulation structures and different
technical requirements,
and its actual process parameters are also different. For example,
VPI has four process
parameters, namely vacuum VI, pressure PI, temperature Ti and time
ti, where I is
1, 2, 3,..., n (n is the total number of VP process and I is the
process sequence).
Insulation structure (W), technical index (a) and resin liquid
characteristics (E) are the
basic functional elements of these four process parameters. The
resin dipping insulation
treatment process of motor and transformer windings has been
through the following stages:
immersion impregnation (ordinary impregnation), then multiple
impregnation, then dripping,
rolling and impregnation, and finally integrated impregnation and
drying treatment process.
It has formed a series of mechanized continuous operation and
automatic control impregnation
process with modern computer technology and PLC technology. This is
a gradual evolution
and development through the promotion of technological innovation,
production demand
and social development. It is this promotion that has produced a
new generation of vacuum
impregnation dryer, high-tech products and famous brand products
integrating
energy conservation and environmental protection.
The new generation of vacuum impregnation drying machine is a
mechanical insulation
process in which the workpiece is put into the impregnating tank
for pre drying, the air
and volatiles inside the coil are removed in the vacuum
environment, and then the
resin is immersed under the vacuum condition by relying on the
gravity of the resin
liquid and the capillary action in the coil, so that the resin
liquid can quickly
penetrate and fill the inner layer of the insulation structure.
FGH process flow → putting in parts → pre drying of windings→
vacuum dehumidification → vacuum impregnation →resin dripping→
cleaning →
return cleaning agent → drying at low temperature and curing at
high temperature →
thermal insulation → unloading. The vacuum impregnation drying
machine carries
a fully sealed and environmental pollution free treatment process
which is
completed at one time.
Advantages of FGH: in the scope of application of FGH process, its
advantages
are mainly in the following aspects:
(1) Improve the integrity. Due to the vacuum impregnation, the
insulating resin
almost completely fills the interior of the insulation, which
strengthens the
integrity of the whole winding. Each part of the winding will not
move separately
during operation, reducing the faults caused by moving wear.
(2) Improve the environmental resistance. The vacuum imprenation
and drying
process is carried out and completed under the condition of fully
sealed container.
The whole drying process adopts hot air circulation heating, and
the waste gas
is recovered and discharged through group A and B condensers, so as
to improve
the working environment and meet the requirements of environmental
protection.
(3) Reduce the operating temperature and temperature rise. Due to
the complete
filling of impregnating resin, the insulating resin can well
replace the internal air
gap and improve the thermal conductivity. It can generally reduce
5-10 ℃ for
motors and transformers.
(4) Improve the performance of the workpiece. Due to the integrated
vacuum
impregnation and drying process, the whole winding is tightly
encapsulated
and soaked by the impregnation resin, and the surface resin film is
smooth
and bright, so that pollutants, wet gas and chemical gas cannot
enter the inner
layer, and the fault caused by the bridging of conductive medium is
eliminated.
(5) Save energy and reduce costs. Due to the integration of vacuum
resin
impregnation and drying, the drying time is two fifths shorter than
that of the
oven, and the drying temperature is 10-20 ℃ lower than that of the
oven,
so as to further increase production, save energy and reduce costs.
