4 replies to this topic

[azarhojabr]

For a tube side condensing shell and tube heat exchanger would you recommended using 3/4" or 1" tube.

Also, what is the maximum two-phase velocity inside the tubes that the heat exchanger should be designed for?

Cooling water is limited to 2.5 m/s but have not seen any guidelines for two-phase flow to avoid tube erosions.

Tubes are carbone steel

[Art Montemayor]

Azarhojabr:

It is very difficult to respond to your query when you fail to cite specific information regarding:

• Is this a pending process design?
• What configuration are you proposing? Is it horizontal or vertical? Is it a straight tube, shell and tube unit or a kettle with a U-tube bundle?
• Give a drawing of the proposed installation to see how you propose to vent non-condensables and drain off the condensed product.
• What are you condensing?

I have designed and operated both a vertical tube-side condenser and a U-tube kettle condenser and I am familiar with the problems associated with either one. Please give us specific details to enable Forum members to give a meaningful response. There is very little 2-phase flow effect in a condenser. I don’t know what you propose, so you should submit a sketch or drawing of the configuration.

[azarhojabr]

it is for a new design

horizontal heat exchanger BEM type

I would like to know if 3/4" or 1" tube is recomnmended. Also, what is the maximum tube velocity for a condensing service?

[S.R.Shah]

azarhojabr:


Please give a drawing of proposed Installation with condensate pipe lining and the questions of Art Montemayor

[Art Montemayor]

I have tried to give the OP some basic clues regarding his insistence on using a horizontal (un-sloped) BEM with condensation inside the tubes. He is going to confront a lot of problems trying to drain the condensate in a steady manner out of such a configuration – especially if he tries to use multi-passes on the tube side.

The size of tube employed or tube side velocity will have little effect on the bad results.

Oh well, that is one way to learn about process heat transfer design.