Improving the Efficiency of Multiple Effect Evaporator to Treat Effluent from a Pharmaceutical Industry
Disposal of effluent from pharmaceutical industry is an increasing problem in India and worldwide. The bulk drug manufacturing process involves usage of more organic and inorganic salts, which is becoming major part of high chemical oxygen demand and total dissolved solids. Evaporation and cooling are the common techniques used to extract available salts and reusable water. The pharmaceutical industry of the study uses multiple effect falling and forced circulation evaporator to achieve zero liquid discharge process for pharmaceutical effluent. Reverse osmosis reject is conveyed to multiple effect falling film evaporator to separate salt and reusable water. This study aims to diagnose the ills of the multiple effect evaporator to improve the efficiency and energy consumption. Diagnosis involves vacuum testing and hydro testing. The former tests revealed leakages in various parts of the multiple effect evaporator. The leakages were arrested and high pressure cleaning along with chemical cleaning was performed to remove the scaling in the evaporator. This improved the efficiency of the multiple effect evaporator significantly resulting in reduction of chemical oxygen demand and total dissolved solids by 91.5% and 96% respectively. This also achieved reduction in energy consumption by 40% reducing the overall live steam consumption from 0.55 to 0.32 kg/kg of effluent treatment.
Sachinkumar Salakki, M A Lourdu Antony Raj, Jagadish H Patil, Vikas Shetty