Alternative Heat Recovery Options for Single-Stage Spray Dryers

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Date

1984

Journal Title

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Volume Title

Publisher

Energy Systems Laboratory (http://esl.tamu.edu)
Texas A&M University (http://www.tamu.edu)

Abstract

Many powdered products are dried to their final moisture content by use of spray dryers. A basic spray dryer mixes an aqueous feedstock with heated air, vaporizing the water in the feedstock and producing the final dried powder in a single stage. Warm moist air is then exhausted to the surrounding environment. This paper discusses basic techniques available for recovering the energy in this exhaust air for use in preheating the spray dryer's inlet air. For illustration purposes the author describes an analysis performed at a milk products plant, where a spray dryer is used to produce powdered milk. Discussed approaches include air-to-air and air-liquid-air recuperates. Key issues include heat recovery potential, capital costs, overall payback, and space considerations. The potential for latent heat recovery is specifically addressed. Secondary issues are identified which can have an important influence on economics and technical approach at a specific site.

Description

Keywords

Heat Recovery, Single Stage Spray Dryers, Recovery Techniques, Economic Analysis

Citation