When piping a continuous blowdown, what is the purpose of using a heat exchanger or flash tank?

Using a heat exchanger or flash tank in a continuous blowdown system primarily serves the purpose of recovering heat before the water is discharged into the blowdown tank. This process is important because continuous blowdown involves the removal of a portion of hot water from a system, which can contain thermal energy.

By incorporating a heat exchanger or flash tank, the recovered heat can be utilized to preheat incoming feedwater or other fluids in the system. This not only increases overall energy efficiency but also helps in reducing the energy costs associated with heating new water that is introduced back into the system. The effective use of these components ensures that valuable thermal energy is not wasted, contributing to a more sustainable and cost-effective operation within the facility.

The other options, while they may seem plausible in different contexts, do not accurately describe the primary function of a heat exchanger or flash tank in relation to continuous blowdown. The main focus is on heat recovery, which enhances the efficiency of the overall process.