COMPARISON of TWO OPERATING METHODS of A PLATE HEAT EXCHANGER UNDER CONSTANT HEAT FLUX CONDITION and THEIR EFFECT ON the TEMPERATURE PROFILE DURING MILK FOULING

摘要

Two methods of operating a plate heat exchanger under constant heat flux were studied: Method A) control by increasing the flow rate of the heating medium; and Method B) control by increasing the inlet temperature of the heating medium. the cross‐sectional temperature variation in the plate used in this study was smaller than that of an intermating‐type plate. A change in the axial temperature profile was discovered as a result of the uneven formation of milk deposit along the channel. the temperature changes of both the milk and the solid‐milk interface (stainless steel‐milk or deposit‐milk) during fouling were larger when the effects of fouling were overcome by increased flow rate of heating medium than when the effects of fouling were overcome by increased temperature of the heating medium. A quadratic empirical model underpredicted the temperatures in the lightly fouled region and overpredicted the temperatures in the heavily foul