The RDX is a machine-mounted dryer that dries raw material with the compressed air in the factory. The manufacturer positions it as an economical alternative to desiccant dryers: compressed air technology provides low operating costs and practically maintenance-free production.
Operating principle
The dryer uses pre-dried air coming from the compressed air network. As the air expands to atmospheric pressure, its dew point falls to a very low value. It is then heated to the required drying temperature and fed into the hopper. In the hopper the air is distributed evenly with a ring nozzle system; thermal insulation separates the hopper from the surroundings.
The dew point of the process air is −25 °C, and it can be brought down to −65 °C if required. Sensors adjust the compressed air volume to demand.
Hopper and capacity
- There are 38 hopper sizes between 7 and 92 liters; the hoppers are entirely stainless round vessels.
- According to the manufacturer's brochure, the typical material throughput is approximately 1 – 30 kg/h.
- The 27, 42, 62 and 92 liter hoppers have a split hopper option that makes cleaning easier.
- The dryer is mounted on the machine; if required, the hopper and the air unit can be separated.
Control
The control unit provides automatic temperature control and drying time monitoring. When production stops it automatically reduces the temperature, and it runs a weekly timer program. Conveying and discharge control are integrated; level control is set automatically. Several dryers can be networked in remote mode; there is a modem output for remote maintenance and analysis. The dew point display works with an optional dew point sensor that can be retrofitted.
Where is it used?
It is suitable for all plastics and can be integrated into all standard machines. Because the dried material drops straight into the feed throat, the risk of it picking up moisture again during conveying disappears. For drying temperatures and times, see our material processing values table.
