Condensate heat exchanger
Cleaning a condensate exchanger
What the return line carries ends up on the plates.
Open the condensate heat exchanger calculatorWhat this is
Cleaning a condensate exchanger.
A condensate return collects corrosion product from every line feeding it. All of it arrives at the exchanger. A strainer sits ahead of the unit for that reason. Fouling shows in two numbers long before anyone complains about the process.
What arrives
The condensate side is not clean water
Corrosion product
Iron oxide from the return pipework is the usual deposit. It arrives after work upstream more often than it arrives by itself.
Why the strainer matters
The strainer ahead of the unit is part of the exchanger as far as this fault is concerned. A blocked pack behind a clean strainer is unusual enough to question.
The two numbers
What says it before the process does
The approach opens up
The gap between the hot side going in and the cold side coming out widens as a film builds. It widens long before output visibly falls.
Pressure drop climbs
A narrower channel costs more pressure for the same flow. Read across the unit at unchanged flow and compare with commissioning.
The strip-down
What the module has to allow
Measure before you slacken
The closed plate-pack dimension is on the nameplate and the pack is tightened back to it. Record it before anything is undone.
Tie bars and the nameplate stay clear
The module is cut clear of both. The strip is not slowed by it, so nothing justifies leaving the cover off afterwards.
The box goes back on
The cover closes over the pack and both end frames on the same geometry it came off. That is the whole point of cutting it to the unit.
Asked about cleaning a condensate exchanger
Questions.
Answers distinguish modelled heat-loss estimates from equipment selection and service guidance.
What fouls a condensate heat exchanger?
Corrosion product from the return pipework, iron oxide most often. A condensate return collects it from every line feeding in, and it arrives at the exchanger after work upstream more often than on its own.
How do you know a condensate exchanger needs cleaning?
Two numbers say it first. The approach temperature widens as a film builds on the plates. The pressure drop across the unit rises at unchanged flow. Either on its own is worth investigating, both together is a fouled pack.
What does the insulation have to allow on a plate pack?
The tie bars and the nameplate have to stay clear, because the pack is slackened and then closed back to the dimension stamped on it. A cover cut to the box comes off before the strip and goes back after it.
The rest of the line