Quincy QBP Blower Purge Desiccant Dryer

Quincy QBP Blower Purge Desiccant Dryer


These dryers combine heat with forced ambient air for regeneration.

Quincy QBP dryers combine heat with forced ambient air for regeneration. As a result, they have a lower purge requirement than both the QHD and QHP desiccant dryer systems. The QBP is available in 13 different configurations that can produce between 210 and 3,400 CFM of dry air at 100 psig.

While they are more expensive to purchase outright than other models, a QBP dryer’s lower ownership and maintenance costs deliver a strong ROI over the life of the product.

After air has passed through the drying tower, a small amount is heated and blown down through the purge tower, where moisture is removed from the desiccant. The blower component improves the overall efficiency of this process, requiring less air to perform the same amount of work. Sophisticated electronic controls and regulators automate the cycle, making it worry- and maintenance-free. Average purge levels are kept to 1.75%.

For optimal performance, run the QBP blower purge desiccant dryer with a Quincy reciprocating or rotary screw compressor and Q-Sorb desiccant. Under normal conditions, Q-Sorb drying beads can provide up to three years of continuous operation.

  • Initial cost: High
  • Operating cost: Moderately low
  • Maintenance cost: Moderately low
  • +20° to -40°F dew point
  • 210 – 3,400 cfm
  • 1.75% Average Purge
  • NEMA 4

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.