miftahazhar
Mechanical
I have problem when calculated dirt factor using Kern Method. From Kern Method we will get calculated dirt factor using formula (Uc-Ud)/(Uc*Ud) and allowable dirt factor from TEMA table. My question is, at what condition the heat exchanger need to be cleaned. is it if the calculated dirt factor > or < allowable dirt factor.
I've read Kern Process Heat Transfer. First he said that if calculated dirt factor> allowable dirt factor, heat exchanger need to be cleaned. At first I okay with it. But then I looked at his example, his example result is calculated dirt factor< allowable one but he said that the heat exchanger is satisfactory. Then at part 11 Calculation for process condition/ design of heat exchanger, in the example, kern said that if we design heat exchanger, calculated dirt factor must exceed allowable dirt factor.
That things make me really confused. So, in the rating problem (decision whether heat exchanger need to be cleaned) calculated dirt factor must greater or lower than allowable dirt factor ? Thank you very much
I've read Kern Process Heat Transfer. First he said that if calculated dirt factor> allowable dirt factor, heat exchanger need to be cleaned. At first I okay with it. But then I looked at his example, his example result is calculated dirt factor< allowable one but he said that the heat exchanger is satisfactory. Then at part 11 Calculation for process condition/ design of heat exchanger, in the example, kern said that if we design heat exchanger, calculated dirt factor must exceed allowable dirt factor.
That things make me really confused. So, in the rating problem (decision whether heat exchanger need to be cleaned) calculated dirt factor must greater or lower than allowable dirt factor ? Thank you very much
