The cold regenerated adsorption dryers of the series HGL dry the compressed air with efficiency and reliability until a pressure dew point of -70 °C. They are compact units, ready for the connection, for wall or floor installation with built-in upstream and downstream filters and designed for volumetric flow rates up to 1500 m³/h.

The inlet compressed air comes into the double chamber system of one tank through the filter of the series FGO: both tanks are filled with a desiccant agent (Activated alumina) of high quality; whilst the compressed air passes through one chamber becoming dry, the regeneration process unfolds in the second chamber. At the beginning, the chamber is opened against the current and part of the dry air passes through the desiccant agent and extracts the damp deposit. At the end of the damp extraction, the operation pressure is recreated into the second chamber so as to start the drying process again in the same chamber. It allows a constant working with the exchange procedure between the chambers, which are equipped with single command pneumatic valves.
The dry compressed air passes through the outlet filter of the series FGO and the network connected downstream. The adsorption dryers of the series HGO work with a regular exchange interval between the chambers. In case of compressed air network with unsteady operating pressure and quantities, the version equipped with dew point meter is available. In this case, if required, a switch of chamber unfolds.
Only when the dew point has been reached, the transition to the other chamber takes place. This
procedure allows the drying process extension, avoiding the airflow regeneration. The compressed air can be dried optionally, depending on a pressure dew point between -20° and -70°C.