Quincy QHP Heated Purge Desiccant Dryer

Description

The QHP series of heated desiccant dryers features a built-in heating system that regenerates the offline tower using half the amount of air as our heatless products. This translates to improved efficiency, less wear and lower operating costs overall.

Nine configurations are available that can deliver between 850 and 3,400 CFM of dry air at 100 psig. Key components include the same high-performance switching valve system found in the QHD and a heavy-duty steel base. From the ground up, the QHD has been designed to ensure long life and low maintenance requirements, even when operating at high temperatures.

Operation is similar to the QHD, with the distinction that purged air passes through a heater before beginning the regeneration process. Because the air is hotter, less is required to absorb moisture from the desiccant beads. Air is forced through the system at a maximum of 50 feet/second, with up to 5.5 seconds of desiccant contact time during the drying phase.

QHP industrial desiccant air dryers run on an eight-hour NEMA cycle. The drying phase lasts four hours, the heating phase two and a half hours, the cooling phase one hour and twenty minutes and the re-pressurizing phase 10 minutes.

The QHP is available with the optional Quincy MicroBurst Regeneration (MBR) system, the only full-load energy saver available for use with heated purge desiccant air dryers. The MBR cuts purge requirements in half and greatly reduces heater “on” time. When equipped with the Quincy MBR, our Heated Purge dryers use 50% less energy. ROI can be realized within five months depending on dryer size and local power costs.

• Initial cost: Moderate
• Operating cost: Moderately low
• Maintenance cost: Low
• -40° to -100°F dew point
• 850 – 3,400 cfm
• 3.5% to 7% purge
• Low-watt density heaters

Operating Principles

Desiccant air dryer systems consist of a pair of towers containing silica gel or another desiccant. Quincy machines use our proprietary Q-Sorb product, an enhanced formula derived from activated alumina that provides improved absorption, lower pressure drop and higher crush strength.

As air passes through the towers, water vapor clings to the desiccant, effectively stripping it from the air until a desired moisture content is met. We measure moisture in pressure dew point (PDP). PDP refers to the temperature it would be necessary to cool air to achieve the same amount of dryness. For example, in many process industry applications, a PDP of at least -40°F is recommended. In other words, air is required to have the same moisture level it would have at -40°F.

Desiccant air dryers work in conjunction with an industrial air compressor. Their dual tower design allows you to time drying operations to a standard NEMA cycle, in which the one tower regenerates (purges) while the other performs the drying function. This prolongs desiccant life and allows for continuous operation for extended periods.

The Importance of Efficiency

A desiccant air dryer system is an important component of any industrial operation in which compressed air of a uniform quality is required. Most air dryers run off electrical power. Because they are for continuous use, however, they can represent a significant operating expense over time.