Donaldson Heat Regenerated Adsorption Dryers are tailor-made to individual customer requirements. This guarantees high reliability and simultaneously efficient operation. Pneumatic Engineering can offer three types of heat adsorption dryers including the HRE Range, HRS Range and the HRS-L Range designed to be used in most environments and applications. View the full range at Donaldson’s website here.

The Donaldson heat regenerated dryers are used in applications including chemical and electrical, machine building, plant engineering, construction and the automotive industries.

The Donaldson HRE heat regenerated adsorption dryers can be used in all climate zones and provide easy maintenance and low investment costs. As with all externally heated adsorption dryers, the desorption of the moisture adsorbed in the desiccant of the HRE models takes place with the heated blower air stream. The cooling of the desiccant is conducted with partial flow of the already dried compressed air. Because the cooling process is independent of the ambient conditions, HRE models can be used worldwide.

With the Donaldson HRS dryers, the desorption and cooling in the system variation is accomplished with the ambient air drawn in by the blower. Compressed air will not be used during the desorption or the cooling phase. Since the desorption occurs in counter current flow, low energy consumption is required. The HRS is therefore the most energy efficient option.

Based on the standard HRS models, the HRS L models of heat regenerated adsorption dryers is designed for processing requirements at tropical and subtropical ambient conditions. These conditions do not allow for cooling with fresh air. The characteristic feature of the HRS L models is a closed loop cooling (loop version). A water cooled heat exchanger cools the air stream heated by the desiccant. From there the cooling air is led back to the inlet port of the blower. Worldwide for all climate zones this version offers a pressure dewpoint of 70°C (94°F).