Heat Recovery

Close enough that the exchanger does not eat the temperature difference you are trying to recover. On many recovery jobs the two streams start only a handful of degrees apart, so every degree of approach is a large share of the prize. We usually run the numbers at a few approach points and let the payback curve show where extra plates stop earning.

Then the exchanger alone cannot help, and the project becomes a storage question. A buffer tank on the sink side can hold recovered heat from one shift for use in the next, at the cost of tank losses and extra pumping. Tell us the timing of both streams, because a mismatch of a few hours is often solvable and one of a whole season usually is not.

Condenser heat into water that is already being heated, and continuous boiler blowdown, are the two that most often come back quickest. Both sources run whenever the plant runs, and both tend to have a sink sitting nearby. Waste effluent projects can be larger, but they carry more cleaning cost and need a plate or bank that copes with the solids.

With a gasketed frame you can, provided the frame is ordered long enough to take the extra plates. That makes it a sensible route when the recoverable load is uncertain or the plant is still growing. Ask for spare frame capacity at the quote stage, since a frame that is already full has to be replaced rather than extended.

The source stream nearly always fouls faster than the sink, and its condition sets the cleaning interval. A selection that looks efficient on clean fluids can lose much of it's duty within weeks on a fouling effluent. We pick the plate type and channel gap for the dirty stream first, then check that the clean side still gets the approach it needs.