Self-adapting vacuum furnaces
The self-adapting process developed by ARRAS MAXEI combines hot air ventilation drying and vacuum drying by alternating convection heating phases and vacuum phases in an optimised manner in order to further reduce drying time and increase energy savings.
Compared to standard processes it takes into account the water vapour tension curve in order to keep the part to be dried in an optimised vaporisation zone and thereby reduce its drying time. The alternating heating and vacuum cycles change depending on the measured humidity levels and stop automatically as soon as the defined dryness target has been reached. This makes it possible to optimise energy costs by running at night and/or on weekends.
By using precision temperature rise control using a PLC to guarantee a consistent inner temperature of the active part to be dried, and then the vacuum phases in which it will cool due to the evaporation of the water (endothermic effect when passing from the liquid to the gaseous state), we reach exceptional levels of efficiency, comparable to « vapour phase » drying process performances on units of up to 120 tonnes for a significantly lower investment and operating budget.
Our vacuum furnaces are made to order depending on customer requirements.
They can be fitted with elliptic movement doors that come to rest along the furnace when opened, or side or vertical movement doors (guillotine door), or even on hinges for top opening parts (lid type).
The vacuum system is fitted with all the instrumentation required to monitor and drive the process. A condenser can be fitted to measure the quantity of evaporated water.
The heating function can be provided by a boiler supplied by us (indicate the energy source) or by a heat source supplied by the customer, on condition that it has been validated by our design office (power and temperature).
Many other options are possible to meet all your needs:
- Filling the transformer in a vacuum when drying is complete
- Built-in coil calibration system during drying (kept under pressure by three press plates on hydraulic cylinders)
- Handling rails mounted on a retractable gantry at the entry to the furnace with or without a manual or motorised cable loading trolley
- Coil heating using low frequency current (LFH)