Dryers semicontinuous

Pure ADU cake from batch precipitation is dried to obtain dried ADUC/UO3 in a box furnace (batch operation)/turbo dryer (continuous operation)/spray dryer (semicontinuous operation). All the three types of units are in use in NFC at the three fuel production plants. 

In order to combine the advantages of batch-type and continuous production, a prototype for a quasi-continuous production line was developed [15-18]. The principle of this quasi-continuous production line is based on a semicontinuous production of minibatches in a specially designed high-shear mixer/granulator connected to a continuous multicell-fluidized-(Glatt Multicell ) bed dryer (see Fig. 7). 

In Table 12-11, dryers in round brackets are semicontinuous forms of batch dryers, not commonly used. Dryers in square brackets are semibatch forms of continuous dryers, also fairly rare. 

Note Most dryers may operate continuously, semicontinuously or batchwise. Labor costs are high f tray d tunnel dryers. 

Dryers of type 1 do not exist in industry therefore, dryers of type 2 are usually called batch dryers as is done in this text. An additional term—semicontinuous—will be used for dryers described in Section 3.9. Their principle of operation is different from any of the types shown in Figure 3.1. 

FIGURE 3.24 Schematic of the model solution for semicontinuous tunnel dryer for cocurrent flow of air vs. truck direction— mass transfer only (a) moisture content in trucks at specified equal time intervals (b) humidity profiles at specified time intervals. 1, 2,3,4—elapsed times. 

The dryers generally used for the drying of piece-form fruits and vegetables are cabinet, kiln, tunnel, belt-trough, bin, pneumatic, and conveyor dryers. Among these, the cabinet, kiln, and bin dryers are batch operated, the belt-trough dryer is continuous, and the tunnel dryer is semicontinuous. 

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