Design Of A Plate & Frame Heat Exchanger 3

[ChemicalAg]

What is the criteria for designing a plate & frame heat exchanger? Any literature I can read and some design equations would be very much appreciated.

Thank You

 

[katmar]

There is very little information on this in the public domain because nobody ever makes a custom designed plate exchanger. They are proprietary units made by specialists. The tooling costs to make a one-off would be prohibitive. The pressure drop and heat transfer coefficients are very dependent on the rib pattern, depth and angle, so it is hard even to model an existing unit.

A small correction on the terminology - they are just called plate exchangers. Plate and frame units usually refer to filter presses.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[someguy79]

For design guidance you may look into API 662.

'Plate and frame' heat exchanger is often used to differentiate between it and 'brazed plate' heat exchagers.

There are other standards and organizations for this stuff, I just can't think of them now. Anyone?

 

[sheiko]

See also:

http://www.cheresources.com/plate_frame_heat_exchangers.shtml

"We don't believe things because they are true, things are true because we believe them."

 

[sheiko]

And:

http://www.apv.com/pdf/brochures/Heat_Transfer_Handbook_1031_01_08_2008_US.pdf

"We don't believe things because they are true, things are true because we believe them."

 

[sheiko]

And i was forgetting this resource (see part II):

http://217.174.18.60/ips/pr/e-pr-771.pdf

"We don't believe things because they are true, things are true because we believe them."

 

[delf]

The plate heat exchangers are desighed for much lower fouling factors than shell and tube heat exchangers. This is due to the turbulence and high wall shear streass that fluid in plate heat exchangers exhibits. The plate heat exchangers were first come up in the 1930s,and maxiumu design pressures for plate heat exchangers can reach in excess of 20 barg.

Generally, shell and tube heat exchangers inadverstently design for disproportionate flow ratios between hot and cold side flow in a plate heat exchanger. This is because shell and tube design require high shell side flow to create as much trubulence as possible on the shell side.


More detail you may refer from

Plate heat exchangers: Avoid Common Misconceptions by Jeff
Lerner Chemical engineering, Be.2009 116,2

Thanks.

 

[Latexman]

PHE's are designed by the vendor (APV, Tranter, Alpha Laval, etc.). Create a performance specification using a form from their site/catalog or a standard form and ask them to quote.

Good luck,
Latexman

 

[rmw]

Sometime about 6 years ago a member of this site put a link to a sizing program that I still use. It is called PHEworks. I have PHEworks 1.0. I don't know if there are later versions or not.

It is really pretty good. I usually have to take an existing Hx and use it to back into a design but once I get it set up, it is pretty accurate when comparing it against vendor quotes.

I googled it and it is out there (and in a later version, it seems)- go get it.

Good luck!!

rmw

 

[ione]

rmw,

Thanks for sharing (version 2.0 available here

http://sourceforge.net/projects/innohex/)

 

[DYV1973]

PHE has a smaller surface area and larger pressure drop than shell and tube. Use smaller fouling coefficients.

Brazed PHE's are cheap, but can not be repaired and cleaned very limited. Limited to small capacities, and thermal length.

Welded PHE's can withstand higher temperatures and pressures, like shell and tubes. There is also manufacturers (APV, Sondex, Tranter, Vahterus) that have plate and shell heat exchangers: high heat transfer coefficient, 1 side mechanical cleaning possible, mechanical properties (pressure / temperature) of a shell and tube.

Please note that a PHE is an excellent filter, however it is not designed for it. So if a fluid contains pulp or fibres, don't use it.

As someone explained above, each manufacturer has itsown design of plates, distribution area at the inlet of a plate, angle, plate gap, etc so you need to ask them for a design. Making your own design and then trying to buy it, will be loss of energy.

Can you mention your application.

DYV

 

[rmw]

Even if you think your fliud is clean, pipe scale can (and will) be strained out very effectively by PHE's if the pieces are larger than the maximum size particle that will enter the plate passes. Good phe designs have strainers in front of them.

GEA Ecoflex also has shell & plate designs as well.

PHE's are successful in applications where there are fibers - think sugar - but only because the passages are large and provisions to blackflow or blackflush are designed into the piping day one.

rmw

 

[quark]

Compact Heat Exchangers by Kays and London is a pretty old text and widely used reference.

 

[Latexman]

Good phe designs have strainers in front of them.

Not in my world, we want the solids to pass through. With careful selection, good operation, and routine cleaning, it works pretty good. With a handle like "ChemicalAg", I would not be surprised at what he's putting through it. Want to share some details ChemicalAg?

Good luck,
Latexman