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[Iz99]

Hi I am working on designing a water shift reactor which is operating isothermally. I have worked out the volume and have to now design an interbed HX. 

The pressure of the incoming syngas is 310C and the pressure is 3550kPa. I know the the heat that needs to be removed from the catalyst is 8553kW. My design will be a multi-tubular packed bed reactor, with CoMo catalyst within the tubes and steam being added (for cooling) co-currently. 

I need help with knowing how to find the number of tubes required do I use the heat exchager formula? I was about to, but then I couldn't figure out what the best temperature of the steam would be to keep the temperature of the syngas at 310C all the way through the tube.

I have tried using the following to find the weight of the catalyt by using a formula that I found in Fogler as follows: 

W = Length*area*bulk catalyst weight

I assumed that the diameter of the tube is 3 inches (OD) - but I don't think this is right as I don't even know if it will cope with a pressure of 3550kPa. 

This gave me about 488 tubes 

Basically I need help with knowing: 

1) What temperature should I use for the steam to keep this reactor isothermal? 

2) How do I correctly find the number of tubes required? Is it ok to just make a size assumption ?? 


Please help. 

Thanks.