Editing Heat exchanger (section)

===Self cleaning===
Spiral heat exchangers are often used in the heating of fluids that contain solids and thus tend to foul the inside of the heat exchanger. The low pressure drop lets the SHE handle fouling more easily. The SHE uses a “self cleaning” mechanism, whereby fouled surfaces cause a localized increase in fluid velocity, thus increasing the [[drag (physics)|drag]] (or fluid [[friction]]) on the fouled surface, thus helping to dislodge the blockage and keep the heat exchanger clean.  "The internal walls that make up the heat transfer surface are often rather thick, which makes the SHE very robust, and able to last a long time in demanding environments."{{Citation needed|reason=Who said this?|date=June 2013}}
They are also easily cleaned, opening out like an [[oven]] where any buildup of foulant can be removed by [[pressure washer|pressure washing]].

Self-cleaning water filters are used to keep the system clean and running without the need to shut down or replace cartridges and bags.