Typical cleaning period for heat exchanger

[dpugliesi]

What is the typical time period required before to clean an heat exchanger? In particular I am interested to know this information for a tubular heat exchanger or evaporator or reboiler (e.g. shell and tube or double tube) in the case in the shell are circulating demineralized water and steam. Thanks.

 

[sshep]

Hey dpugliesi,

I think the process side will dictate the cleaning. Tubeside design should favor easy cleaning. Demin water and steam should be very clean, so the shellside may never need cleaning over the life of the equipment, or perhaps a mid-life chemical cleaning.

Check the exchanger foaling factors to see how dirty the service is assumed to be.

Best wishes,
Sshep

 

[dpugliesi]

Thank you.

 

[dpugliesi]

Regarding the fooling factors, do you mean to check them in literature or experimentally?

 

[MJCronin]

I am a firm believer in experimental testing of the fooling factors......

MJCronin
Sr. Process Engineer

 

[sshep]

Dear dpugliesi,

Fouling factors must be supplied on the data sheet when purchasing an exchanger. These are either supplied from personal experience with equipment in similar service, or via literature values (other peoples experience). Round numbers are used to reflect very little, little, medium, or heavy fouling. If you don't know then you will be conservative, and worst case the exchanger is oversized.

With respect to the original question of cleaning, an exchanger in heavy fouling service will be cleaned every shutdown. It should be sufficiently sized to match the shutdown frequency by specifying fouling factors expected at end of run condition.

best wishes,
sshep

 

[racookpe1978]

Have you ever seen a HX with shell-side openings for steam/water brush cleaning without full head removal to pull the the tubes ? Kind of like a steam-cleaner on a boiler with moveable head and rotating spray through a W/T plug or opening?