Tube cleanliness factor

[Corgas]

Colleagues;

On data sheet for a surface condenser I noticed that "tube cleanliness factor was included" = 85%.

Does it means that I need at least 85% of total cooling surface cleaned in order to perform according to design?

Thanks,
Corgas

 

[EdStainless]

No, it means that you need a copy of the HEI Condenser Standard.
The tube cleanliness factor is the ratio of the heat transfer coef compared to the clean value.
For Cu alloys 85% is real clean. In service it is common to see values down to 60%.
Stainless steels (and Ti) can usually manage 95% or better when they are new or freshly cleaned. They also can foul and end up down at 60% if the plant is careless.

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Plymouth Tube

 

[Corgas]

Thanks EdStainless (Materials).

What does HEI stand for?

 

[metengr]

Heat Exchange Institute

http://www.heatexchange.org/

 

[EdStainless]

specifically

http://www.heatexchange.org/pub/steamsurface.htm

If you do any condenser work you must own a copy of this.

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Plymouth Tube

 

[rmw]

To put it in layman's terms, tube cleanliness factor is to the HEI method of calculation what fouling factor is to others. It is a method of accounting for the addition of surface area to the required surface area to make provision for future fouling (or account for present fouling if calculating an existing condenser.)

It is used in conjunction with other factors such as tube velocity factor unique to the HEI method.

rmw