Heat Exchanger Design
Heat Exchanger Design
(OP)
Good Evening,
I am currently desiging a heat exchanger to heat Air from 10 oC to 110oC and cool flue gas from 1259.4 oC to 725 oC.
As both fluids are gases, i would like to know if it is advicable to use a shell and tube heat exchanger?
I read online that the convertional gas-to-gas heat exchanger is vertical shell and tube heat exchanger
Thank You Very Much
Kind Regards
Paul
I am currently desiging a heat exchanger to heat Air from 10 oC to 110oC and cool flue gas from 1259.4 oC to 725 oC.
As both fluids are gases, i would like to know if it is advicable to use a shell and tube heat exchanger?
I read online that the convertional gas-to-gas heat exchanger is vertical shell and tube heat exchanger
Thank You Very Much
Kind Regards
Paul





RE: Heat Exchanger Design
A shell and tube design could be used for this. However, it really depends on the operating pressures. If both sides are operating at essentially atmospheric pressure, then your optimal design may be more rectangular.
Gas to air heat exchangers are generally fabricated using either tubes and tubesheets, or are plate type. Either one may work in your case, and it could be done with a simple cross-flow exchanger since the temperatures do not cross. However, your hot gas is VERY hot, and you will need to pay special attention to your materials of construction. Another problem area is differential expansion and leakage.
Regards,
Speco
RE: Heat Exchanger Design
RE: Heat Exchanger Design
One thing I forgot to add. Since both air and flue gas are poor heat transfer media, you need as much pressure drop as you can get in order to get a decent heat transfer coefficient.
Good luck!
Speco
RE: Heat Exchanger Design
If you are heating the combustion air, you'd be better off using a hot radiator (finned exchanger installed in the air duct) to heat the air. That's the cheapest way to heat air and the control is very easy. In any case, the finned heater is far better option than expensive TEMA exchangers.
Cheers,
gr2vessels
RE: Heat Exchanger Design
Rotary regenerative heat exchangers (slowly rotating plate type) are the best and most economical solution for this gas to gas HX.... a Ljungström ! !
http
http://www.thermopedia.com/content/1087/
http://en.wikipedia.org/wiki/Air_preheater
Ask any coal fired power plant ! !
RE: Heat Exchanger Design
RE: Heat Exchanger Design
Now that is a 100+ year old technology that can't seem to die. Wow, think if Stanley Steamers had been as resiliant.
rmw
RE: Heat Exchanger Design
Tell us, do you design a power station?
RE: Heat Exchanger Design
rmw
RE: Heat Exchanger Design