Overview of Dryers, Dryer Selection and Design

In the following section, an overview of the classification of technical dryers, their selection, their operating mode, and design 

The dimensioning of the dryer is then quite simple if the required drying time (see Chapter 5.5) is known. The required dryer volume V is 

A calculation for the first stage of a convection dryer is possible when the heat transfer coefficient a, and the volume specific product surface a as the phase boundary surface are known. In a differential dryer volume Aq - dz the gas temperature decreases in the direction of flow z by di with an approximately constant product surface temperature 1 0. While the gas moisture load increases, the corresponding moisture content of the product decreases (see Chapter 5.4). When neglecting the portion of the heat flow of the moisture load in the gas, the heat flow rate dQ transferred through Aq dz is 

Convection dryer Product rests on rigid surface 

On integration, this gives the required dryer length or height Z, for mass and heat transfer 

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