3 replies to this topic

[seeker_of_knowledge]

Hi there,

 

I am trying to find out if there is any guidelines on considering leakage from high pressure to low pressure side as one of the possible overpressure scenario in SPIRAL HEAT EXCHANGERS? Can someone please comment.

 

Thanks,

 

Fez

[paulhorth]

Fez,

I don't have experience of specifying spiral heat exchangers - but I would expect that, due to their structure, there would be practically no cost penalty if both sides were specified with the same design pressure. This would eliminate the leakage overpressure scenario.

The high design pressure for the low pressure side would need to be continued out to the isolation valves on the piping at the inlet and outlet.

 

Paul

[Art Montemayor]

Fez:

 

Paul is exactly correct in his analysis of Spiral Plate heat exchangers.

 

However, there is another type of spiral exchanger - the tubular version with which I have had a lot of experience.  Please refer to the attached document.

 

In the early 1960's I did a lot of applications of Graham Heliflow exchangers and found them to be compact, highly efficient, low cost, and robust.  Some of our applications were as compressor intercoolers, with gas pressures up to 3,000 psig.  However, we discovered an Achilles's heel in the product at that time: the casing was mostly cast iron (for cost) and there was no protection for the shell in the event of tube failure.  What I did was to machine a screwed nozzle in the casing and introduced a bursting disc made of thin aluminum plate.  This worked well and we advised Graham of our findings and comments.  They agreed and immediately started to install burst discs in their casings.  I believe that they incorporate shell protection in all their units now.

 

As Paul states, if you have a significant pressure difference between the two fluids in a spiral heat exchanger, you are well advised to protect the low pressure side.  In the case of plate spirals, the pressure difference between both sides is generally not significant and, as Paul states, the same pressure rating is generally designed into both sides.

Attached Files

•  Spiral Tube Exchanger Applications.docx   2.7MB   54 downloads

[seeker_of_knowledge]

Thank you Paul & Art.

 

Warm Regards