What is the function of a blowdown tank?

A blowdown tank is specifically designed to separate solids from the liquid that is discharged from a system, such as a boiler. During operations, water may accumulate impurities, including dissolved solids and sediment. When blowdown occurs, this water is released to reduce the concentration of these impurities in the system.

The blowdown tank allows the heavier solids to settle at the bottom, while the relatively cleaner water can be either reused or discharged in a controlled manner. This function is crucial for maintaining the efficiency and longevity of a boiler system, as it helps prevent scaling and other issues that can arise from the accumulation of solids.

For the other options, cooling the water involves different mechanisms, typically focusing on heat exchangers or cooling towers, which do not relate to the primary function of a blowdown tank. Storing used oil is a distinct process related to oil handling and does not pertain to the treatment of water or separation of solids. Preventing backflow is a crucial safety measure in plumbing and fluid systems, achieved through devices like check valves, rather than the function of a blowdown tank.