All entries for Sunday 14 May 2006
May 14, 2006
Writing about web page http://www.engineeringtoolbox.com/overall-heat-transfer-coefficient-d_434.html
Heat Exchanger problemo
Hi - I thought I'd put this up here as Warwick blogs scores pretty high on Google these days with then promise that somebody better informed than I might be able to lend some technical advice.
Here's the problem– I'm building a heat exchanger based on a system that is used in small scale breweries such as this – link
although his design is fairly rubbish.
I need to work out the length of coil that I should need to facilitate efficient heat exchange so that in one pass through the system I can heat the flowing liquid to at least 75o centigrade?
I've been studying the engineering equations on this site–>
and I have retraced my old Chemistry as far as Specific Heat Capacity and the like but I'm fairly nay you might reveal to me that I am completely lost.
What approach or equations are relevant that I should I embark upon to work out the length of the coil?
It's clear that variables include the material that the pipe is constructed from, its thickness and it's fair to assume that the liquids on both sides of the exchanger are water. So its simply a matter of being able to work out at what rate the heat can be transferred from the hot side to the cold side of the exchanger?? and with this in mind and by knowing or varying the flow rate of the liquid it should be possible to work out the length of the pipe needed to get near enough 100% exchange with regard to equalizing the temperatures???