Drainage collection system

A drain recovery system that recovers drain being generated by condensation of steam having been generated at a boiler and used at a load device and that supplies the drain to the boiler, the drain recovery system comprising:

• a buffer tank that stores the drain generated at the load device;
• an assist tank that is disposed below the buffer tank;
• a plate-like member, which is disposed below a steam inlet of the assist tank, configured to deflect the steam in a horizontal direction;
• a first drain supply line that connects the load device and the buffer tank to each other to supply the drain generated at the load device to the buffer tank;
• a second drain supply line that connects the buffer tank and the assist tank to each other configured to allow the drain stored in the buffer tank to flow out of the buffer tank and to flow into the assist tank;
• a drain supply valve that opens and closes the second drain supply line;
• a communication line that connects the assist tank and the buffer tank to each other to establish communication between an inner space of the assist tank and an inner space of the buffer tank;
• a communication valve that opens and closes the communication line;
• a steam supply line that connects the boiler and the assist tank to each other to supply the steam generated at the boiler to the assist tank;
• a steam supply valve that opens and closes the steam supply line;
• a feedwater line that connects the assist tank and the boiler to each other to supply the drain stored in the assist tank to the boiler;
• and
• a feedwater pump that is disposed at the feedwater line,
• wherein a downstream end of the second drain supply line is connected to a bottom part of the assist tank, so that disturbance of a liquid surface of the drain flowed into the assist tank is minimized and heat exchange at an interface between the steam and the drain in the assist tank is restrained.