3 replies to this topic

[Daniel James]

Hi all,

 

 

          I've got a question regarding HTRI Rating of Existing Heat Exchanger. Is it necessary for me to input a fouling factor for both tubeside and shellside fluid during evaluation of an existing running exchanger? Without fouling factor specified, HTRI is returning an overdesign of 50%. With fouling factor specified on tube and shellside, the overdesign drops to -5%.

 

Shellside fluid = medium pressure clean steam

Tubeside fluid = Process water and ethylene oxide (demin water quality)

[cea]

What is intent of your activity, is it to check performance for current duty/ service or to check performance for revised / alternate duty / service? Is your new process fluid prone to fouling?

 

Please indicate your intent of exercise or background for this drive, then only we shall be able to help you. 

Edited by cea, 14 June 2016 - 06:19 AM.

[Daniel James]

What is intent of your activity, is it to check performance for current duty/ service or to check performance for revised / alternate duty / service? Is your new process fluid prone to fouling?

 

Please indicate your intent of exercise or background for this drive, then only we shall be able to help you. 

 

Sorry for the missing info. My intent is actually is to check both the current performance and the revised service later on.

[cea]

Well, if your intent is to check current performance of exchanger, then you should consider actual fouling factor for given service. In case, if you still get -ve over design, it simply means the exchanger is under design.

 

The obvious observation in such cases are more flow of utility stream to exchanger (utility stream control valve tend to open full), higher return temperature of utility stream (in case of thermic fluid), process stream outlet temperature is less than desired.

 

In such cases, the only option is to take shut down & clean the exchanger.