Q & A > Question Details
We are planning to procure a new airpreheater for furnace with two cells K1 and K2 cell one for prefractionator reboiler and the other crude heater for fractionator.
I am just filling the process data sheet. On what basis should I fix the pressure drop across the air side and flue gas side?
27/05/2010 A: SUNDEEP GUPTA, BECHTEL, sundeepgupta1@rediffmail.com
If you are a Process Engineer, then you do not specify the max differential pressure across APH or flue side system of a Heater. The Thermal designer of the Heater is going to perform the hydraulic analysis and do the needful.
In the API datasheet, you can simply ignore those inputs and mention that to be given by the vendor.
21/05/2010 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
The basis should be what the overall pressure profile requires. Whether there will be a force draft blower or an induced draft blower, the procedure for the calculations are the same. First, set the desired pressure in the two fireboxes. Then work through the convection sections, the stack, air preheater, ID blower (if any) and on to the atmosphere. Then, work backwards from the firebox through the air preheater and FD blower (if any) to the atmosphere. The pressure profiles will indicate the pressures in and out of both sides of the air preheater. In other words, a complete system step by step pressure drop calculation is needed.