Regenerative Desiccant Dryers

Regenerative Desiccant Dryers

Regenerative Desiccant Dryer Principle

The Regenerative Desiccant Dryers are used for drying air in storage tanks or pneumatic systems and are beneficial in the drying of hygroscopic (water-absorbing) resins. These dryers remove water from the air by passing it through a desiccant that absorbs moisture.

Features

The Regenerative Desiccant Dryers consist mainly of two cylinders containing desiccant, connected by a valve system.

Operation

When the desiccant in the first cylinder is saturated, the air flow can be switched to the cylinder containing the dried desiccant.

Dessicant Types

Common desiccants are silica gel (an oxide of silica), alumina (aluminum oxide) and calcium sulfate (the anhydrous form of gypsum).

Types of Dryers

While manual desiccant dryers exist, many dryers are regenerative desiccant dryers, as noted in the Plant Services magazine article, "The Economics of Operating Regenerative Desiccant Dryers," by Noel Corral and Andrew Sheaffer.

Most Expensive

Heatless regenerative desiccant dryers run a portion of dried compressed air through the previously utilized cylinder to extract moisture from its desiccant.

Least Expensive

Heated purge regenerative desiccant air dryers use less air than the heatless variety in addition to heat, which helps the air carry away more water as it passes through the saturated desiccant.

Best Compromise

Heated blower purge regenerative desiccant air dryers use air from outside the dryer that is heated and sent through the water-saturated desiccant for drying.

Classification

There are different types of regenerative desiccant compressed air dryers. These are:

• Small Heatless Desiccant Air Dryers
• Large Heatless Desiccant Air Dryers
• Compact Heatless Desiccant Air Dryers
• Mini Heatless Desiccant Air Dryers