Re: One way to end the "blues"

I looked into this vortex cooling concept for an application on a train.  The refrigeration efficiency compared with a vapour compression cycle is dreadful, so it is not a viable scheme for "base load", but where low capital expenditure can be balanced against high running cost for occasional use, fine.

In any case, whilst compressing air in the normal way does indeed make it hot, if you then cool the pressurised air in an aftercooler or receiver, and then expand it as you do when using a jet, it will cool below the starting temperature, and it can be drier as well if you remove the condensed water after the aftercooler or from the receiver. Vortex not needed.

Sorry Lance, compressed air is very much not a free fluid.  Air compressor and motor efficiencies are such that you need a compressor with a 10 HP electric motor to run a 1 HP air motor continuously.  Stick to electric hand tools!


From: "Lance Eggleston gbof@... [SOUTHBENDLATHE]"
Sent: Wednesday, 16 December 2015, 18:45
Subject: [SOUTHBENDLATHE] One way to end the "blues"

Group, < pics at the end>

Are you pushing your cut,
making the cutter tip blue
and the work curls blue/black?

Is the work piece too hot to handle after
the cuts are done? Does the cutting liquid
boil when dripped or brushed onto the work?
Inhaling stinky vaps from the boiling liquid?

I have an alternative that uses a FREE fluid!
Cold compressed air..

You say air gets hotter as it is compressed, yes…
but push that air into a Vortex Tube < aka Maxwell’s Demon >
and wah-la cold air comes out one end 
whilst hot air comes out the other.

By balancing the air pressure/volume into the vortex tube
and the hot air volume leaving, you can produce a stream
of COLD air. Direct that air through a common jointed cooling tube
and you get:

Cool cutter tip
cool work piece you can bare-hand after the cuts
no thermal expansion of the work 
no stinky vaps
no “soap” glued swarf on the lathe bed
no recurring cost to coolant liquid
both hands to work the machine

compressor is noisy
air jet can be noisy
must direct chip flow correctly


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