Abstarct
A new more productive crystalliser named coil crystalliser (CC) has been designed in this study for application in Progressive Freeze Concentration (PFC) process, where the system is to crystallise the water component in a solution and leave behind more concentrated solution. Ice crystals are formed as a layer at the inner wall of the copper crystalliser immersed in a coolant filled refrigerating waterbath as the temperature is brought down below the freezing point of water. In the subsequent performance analysis carried out using glucose solution as simulated industrial wastewater treatment, it was found that the effective partition constant (K) was satisfactorily low at high
circulation flowrates, low initial concentration and intermediate coolant temperature. PFC strongly involves heat transfer activities between one fluid to another through a medium (commonly a metal). In this case, the heat is transferred from glucose solution to the copper wall and subsequently to the coolant liquid, where a heat transfer study is deemed necessary to assess its performance. The most common feature to be investigated for a heat transferring equipment is its overall heat transfer coefficient, U, which is a measure of the overall ability of a series of conductive and convective barriers to transfer heat. In the heat transfer study, standard lines for overall heat
transfer coefficient (Uo) were plotted against time, according to coolant temperature. The best Uo was found to be generated when the coolant temperature was between -6 and -8°C. The U lines then facilitate in generating a model to predict ice crystal mass produced, originated from a heat balance analysis. Error analyses have proven the model’s reliability with R-squared of 0.997 and Absolute Average Relative Deviation (AARD) of 10.6% between experimental and model data, with the highest predicted mass of 973.2g.
Click this link for view full paper: 1490_Prediction of Crystal Mass through Heat Transfer Study for a Progressive Freeze Concentration System-Revised
