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editTagged as mech. eng. Looks like chem. eng. to me. —DIV (128.250.204.118 01:51, 4 July 2007 (UTC))
- these devices are used very frequently in HVAC and therefore I have added Engineering tagsPahazzard (talk) 23:14, 21 January 2011 (UTC)
Most ChE heat transfer is based on ME texts.
Seems only the PhD's of the ME world can handle it ;) —Preceding unsigned comment added by 167.136.242.40 (talk) 18:13, 27 June 2008 (UTC)
- I don't think this article explains where the two fluids flow and how they are kept apart, which is the whole essence of a heat exchanger. The following passage should say this but doesn't seem to (and it also contains evident vandalism where it says "finest lolsed"):
"In place of a pipe passing through a chamber, there are instead two alternating chambers, usually thin in depth, separated at their largest surface by a corrugated metal plate. finest lolsed in a plate and frame heat exchanger are obtained by one piece pressing of metal plates."
I cannot amend the vandalism because I cannot tell what the words should have been. "Two alternating chambers" is clearly too few. Is the intended meaning "A series of solid thin plates are separated from each other by a very small gap (about 1.5 mm). The perimeters of the plates are sealed. Hot fluid is fed through [but how? - this is the bit I don't understand] every second gap, and cold fluid through the gaps in between. The hot and cold fluids are thus kept apart. By the time it has reached the opposite end of the plate, the cold fluid has been warmed up by its near contact with the hot fluid on either side of it, and the hot fluid has cooled down correspondingly. Then all the cold fluid is brought together again by one manifold, and all the hot fluid is brought together again by another manifold."?
The blue and red diagram lacks detail and is not properly labelled: the red and blue arrows no doubt mean hot and cold fluid, but this is not stated; and it is impossible to see where the two fluids flow or how they are kept apart. The plates should not be coloured alternately red and blue (hot and cold) because each plate (I presume) is hot on one side, cold on the other. UBJ 43X (talk) 11:09, 19 November 2008 (UTC)
Plate Heat Transfer Equation
editU isnt calculated with the simple temperature difference, afaik it is calculated with log mean temperature difference. References: http://www.google.de/search?q=LMTD+"plate+and+frame+heat+exchanger"+"overall+heat+transfer+coefficient"