Shell and Tube Heat Exchanger

There is no way to tell. It depends first on the total surface area of the tubes, second on the tube wall thickness, third on flow considerations around the tubes, and possibly on other minor factors.

There are a number of reason where it depends...m a few at the top of my head...

• the number of tubes is mainly dependent on the flow rate, the flow rate needs to be turbulent flow (determined with the Rey olds Number) for best thermal transfer to eliminate/reduce laminate boundary layers that act as insulators.
• The number of tubes is related/specified with higher viscosity of product. To have the ΔP at an acceptable level
  
• this is also not only for the number of tubes required, but also for the size (diameter) of the tubes.

There is no way to tell without a detailed dimensioned description of the equipment and the conditions of the fluids involved. Consult a local Chemical Engineer, not a Mechanical one.

The number of Heat exchanger tubes should always be a Prime Number.

Therefore, a HX with 41, 73 or 101 tubes is acceptable. Both 604 and 49 are not prime numbers

Huh? On what grounds? For instance, on multi-pass exchangers, that would make it impossible to divide the passes equally.

What ????, that’s Ridicules,

I’ve had not only designed shell and tube heat exchangers, I also wrote a program to size heat exchangers. Prime numbers has nothing to do with it, what has to do with it, to name me a few are;

• Reynolds Number which is tied to the fluids viscosity
• Thermal Conductivity of the fluid as well as numerous other components.

and to determined the heat exchangers efficiency and its ability you need to solve a number of variables and dimensionless numbers such as Reynolds number, but also the Prandtl number and Nusselt number simultaneously through iterations. And it never had anything to do with having prime number of tubes...

but out of curiosity, I like to hear you explain the reasoning, and not what’s prime and what’s not, but why does it have to be a prime number if you can that is.