In the chemical and pharmaceutical industries, blow down means the application of condensers to vent solvents on reactors in manufacturing plants. The gases that escape from the reactor vent, such as air, nitrogen or other, bring with them the solvent which is carried away. To prevent the solvent from ending up in the environment or the atmosphere, a heat exchanger is positioned on the vent acting as a sort of ‘cold trap’.
The freezing water that circulates inside the heat exchanger actually condenses the solvent, achieving an initial temperature reduction. The solvent thus precipitates and can be recovered or thrown back into the reactor. The exhaust fumes treatment system can therefore safely provide for the correct disposal of the solvent.
Examples of applications for blow-down:
Plate heat exchanger on chemical blow down.
Vacuum pump condenser.
Vacuum condenser on concentration plant reboiler.
