EFFECT OF FLOW DISTRIBUTION ON SCALE FORMATION IN PLATE AND FRAME HEAT-EXCHANGERS

The uncertainty in the performance and reliability of plate and frame heat exchangers under fouling conditions is one of the main reasons wh y the chemical and process industry does not fully appreciate this typ e of heat exchangers' obvious potential for cost and energy savings. R ecent investigations have shown that similar heat exchanger plates wit h different corrugation patterns fouled at very different rates under identical process conditions. These differences are attributed to the effects of flow distribution on fouling rates in the plate channels. T hese effects have been investigated experimentally using commercial he at exchanger plates together with transparent polycarbonate plates for visual observation of flow distribution and fouling deposition. The h eat exchanger's fouling rate was found to increase with decreasing flo w velocity and increasing solute concentration. Several fouling mitiga tion methods were also investigated. Experiments were performed with A cronitrile Butadiene Styrene (ABS) particles suspended in water in con junction with a transparent polycarbonate plate to study the flow patt erns in the plate channels. To improve the design of heat exchanger pl ates for longer operational cycles, it may be necessary to redesign th e plates to obtain a more even flow distribution in the plate channels .