Tube Side Velocity Limit for Shell and Tube Heat Exchangers

Hi All,

We are designing to be used as gas cooler for my plant. The tube side is the process gas at 26 psig to be cooled from 220 Deg C to 175 Deg C using Boiler Feed Water(BFW) on the shell side. I have a question on how much can the tube side velocity be increased while being the allowable pressure drop without reaching the erosional velocity limits.

Based on the preliminary Aspen EDR runs the tube side velocity is 60.97 ft/sec ( 18.5 m/sec) and the tube side pressure drop is 0.19 psi while the allowable pressure drop is 0.74 psi. There is up to 0.54 psi of pressure drop that can still be utilized to convert it to heat transfer to reduce the heat transfer area but want to make sure that we don’t hit the erosional velocity limit. The thread below says a velocity limit of 25 m/s (82 ft/sec) for carbon steel tubes for the air cooled exchanger. In my case the tubes are Duplex 2205. Does this limit of 25 m/sec apply to Duplex steel as well?. Also I want to know how does the tube side Rho. V^2 limitation play role in the tube side velocity limitation. Kindly quote the references which gives guidelines on these.

Thanks and Regards,
Pavan Kumar

1 Like

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