HLD Series Modular Desiccant Compressed Air Dryer

Energy Saving Purge Optimizer

In practical situations, the airflow through the dryer is not maintained at the maximum flow value that the equipment is designed for. The moisture load may also vary. During these times, less purge-air may be required to remove the moisture from the desiccant in a tower. HLD dryers feature a purge economizing feature that can reduce the amount of purge air used by changing the regeneration.

Reduction of the percentage of air purge regeneration flow is based on a controller setting. It has 4 options - 40%, 60%, 80% & 100% purge optimization cycles respectively. The settings correspond to flow or moisture load through the dryer. There are separate LED indicators for Tower Status, Purge Optimizer & Condensate Drain

HOW DOES A COMPRESSED AIR DRYER WORK?

Air coming from any compressor is 100% saturated for that pressure and temperature combination. When air travels downstream, the temperature drops which results in the formation of condensation. This condensate water is detrimental to downstream equipment, and it may affect downstream critical processes or even cause corrosion. To avoid this compressed air dryers are used. There are different types of air dryers available based on the application. The most popular option is refrigerated air dryers. However, for applications that demand ultra dry compressed air - desiccant dryers needs to be used.

ELGi HLD modular desiccant compressed air dryers remove moisture and water vapor to as low as -40°F PDP to cater to the demanding applications downstream and ensure quality compressed air, meeting class 2 quality.

Working Principle

Stage 1 : Moist compressed air enters the desiccant-filled drying Tower 1 through the 3/2 Valve

Stage 2 : Up-flow drying enables the desiccant to strip the air stream of moisture. Clean, dry compressed air exits through NRV

Stage 3 : When in regeneration mode, Tower 2 depressurizes to atmosphere through the muffler when the exhaust valve opens

Stage 4 : Purge air (dry compressed air) is diverted before exiting through the bypass valve into Tower 2 and exits at exhaust valve to desorb the moisture from the desiccant. Once desorbed, exhaust valve closes, and Tower 2 is repressurized

Stage 5 : At tower shift-over Tower 2 will be placed on-line to dry the bed. Operations will switch and Tower 1 will be regenerate