- Jun 2, 2009
--- In Distillers@yahoogroups.com, Rasputin Paracelsus <rasputin@...> wrote:

>

> Hello

>

> A while back I asked a question about setting up a VM on a 3" column

> rather than 2". There was some variance in opinion with regards to the

> constriction of the vapour for turbulence purposes. (I note this here

> only for the record, it's not really the focus of my question this time

> around.)

>

> Supposing that problem were to be solved in an acceptable fashion--I am

> wondering about the Cross-flow condenser itself. Given that the

> cross-sectional increase is 2.25:1 (3-squared over 2-squared)

>

> * would I then want 2.25 times as much surface area in terms of

> coolant pipes?

> * if so, perhaps most simply implemented by using 2.25 times more

> pipes of the same size (smaller pipes yield greater surface area

> per volume than larger ones) and

> * presumably this would mean a correponding increase in pump power...

>

> (I assume I can sort out the question of the liebig adjustment without

> too much problem using the handy calculator on the homedistiller site...)

>

> Thanks

>

> R

>There's a lot of "fudge factor" built in to a 2" crossflow. Increasing the coolant flow volume is the easiest way of removing heat and ramping up performance of any existing condenser. Because there is little restriction/resistance in the crossflow's multi-tube coolant arrangement (parallel flow), you can increase the coolant flow considerably to suit the amount of vapor being fed in.

That's a decided advantage over coils, which must be designed to suit the particular rig's vapor capacity. Coolant flow in coils has limited adjustability due to high friction (requires high-pressure pumping).

It's not unusual to have coolant flows of 6+ litres per minute in a 2" crossflow.

However, if for some reason you don't want to up the coolant flow, and you want to design a larger one specifically for your volume & velocity of vapour flow, then you could start by studying the following basic math and parameters. It ain't as simple as people think.Slainte!

regards Harry - << Previous post in topic Next post in topic >>