Thread: "Flood Cooling" with Air?

Originally Posted by ventureoverland

Guys,
Last weekend I ran out of cooling fluid and wanted to get a small job finished on the lathe. I recalled watching one of Adam Booth's Youtube clips that shows his mist cooling arrangement on his mill. They say that necessity is the mother of all inventions, so whilst I didn't have mist cooling abilities I did have some air available and wondered how I could utilise that.

My rather heath robinson attempt to provide additional cooling to the tipped tool was to hold the blow gun a small distance (75 - 100mm or so) away from the tip. Granted I wasn't taking heavy cuts (on my Hercus 260) but heavy enough into 2" DIA 316 Stainless to think I should cool things down a bit.

Im fairly sure this method worked although of course I can't quantify it and I know its no where near as efficient as liquid. I also know that in the absence of a flood cooling system, applying a constant air flow to the tip by attaching it to the saddle is easier, more consistent and smells less that applying oil / fluid with a brush.


I know there is the whole debate about cooling tipped tools (or not) and thermal shocking the tips with sudden cooling.


My question really is to do with benefit - do you think there is any benefit of pursuing this to a more permanent solution? Im thinking of a small brass ball valve with a nozzle on one end and an airline at the other. I already have a suitable mounting point on the saddle, left by the previous owner.

Thoughts please.

R
J

cooling by forced air induction is much much less efficient than coolant

but better than nothing in an emergency I guess

As eskimo says straight air is much less efficient than coolant.
Weight for weight and at a given temperature, air has 4 times less the heat carrying capacity of water but because air is about 1000 less dense than water, air can only carry away about 1/4000th the amount of heat that water can carry.

Using compressed air as a coolant is well advanced and much more efficient with something called a Vortex tube.
eg http://www.vortexair.biz/Cooling/SPO...otcoolprod.htm, http://www.vortec.com/t-video-vortextubes.aspx
The vortex tube generates much colder air than a simple expanding stream from a compressor. It's still a long way short of simple coolant but has useful applications in some areas.

A good flood coolant setup should not smell at all or should only faintly smell of oil. If it smells rotten then there are bugs growing in it. My method of controlling bugs is to run a cooling loop which consists of a 20 mm PVC pipe loop and a water feature pump that rapidly pumps a relatively large amount of coolant above the lathe bed and then back down through a return pipe into the half filled tank. The coolant falls through the open tank mixing with air which oxygenates the coolant and reduces bug growth. At the top of the 20mm loop I have a small T piece that taps off at coolant via a 1/4" tap and this goes through a pipe to the work piece.

Before I had this system I used to have to clean the tank every few months but no I clean the tank about once a year but it very rarely smell.

Air is the coolant of choice when cutting plasics.

We use air blast cooling at work. Mainly for milling as the lathes have really good flood cooling systems on them. Our tool suppliers actually recommend dry machining if you cant supply a constant flood of coolant on the tool. Just out of interest what grade of inserts are you using? The disadvantage with dry machining is the part can get quite hot and throw your measurements out. what i normally do is rough the part down cool it off then finish it. Hope this helps.

I had this dilemma when sourcing a cooling system for my cnc router.
Flood cooling was too messy and air by itself was not effective enough.
I settled on a mist cooler called Fogbuster. The whole package was a bit steep, for what it was so I just purchased the head unit and hoses and sourced the rest of the material myself.
It ticks all the boxes for me. It uses very little water, a moderate amount of compressed air and is very effective. You can adjust the water flow on-the-go and just use air if you wish.
I read somewhere that these are 90% as effective as flood cooling...who knows....
The cost was about $175US and I acquired a water filter housing, regulator and solenoid.
Not sure how much air is consumes, but my 12 CFM compressor starts only once or twice during a 10 minute job.

I have seen and used Vortex coolers at work. they work very well and produce a very cool stream of air, as well as a hot stream of exhaust air, but they consume quite a large amount of compressed air.
We have some 'pencil' sized units at work and they are rated to 35 cfm. they also cost about $500 ( I think? )

Steve

Originally Posted by snapatap

We use air blast cooling at work. Mainly for milling as the lathes have really good flood cooling systems on them. Our tool suppliers actually recommend dry machining if you cant supply a constant flood of coolant on the tool. Just out of interest what grade of inserts are you using? The disadvantage with dry machining is the part can get quite hot and throw your measurements out. what i normally do is rough the part down cool it off then finish it. Hope this helps.

Thanks.

Currently I have some ISCAR WNMG roughing inserts, some small ISCAR CCMT boring tips and a few ISCAR DGN parting inserts.