On Friday 22 March 2019 10:06:24 Les Newell wrote: > That's basically the Fogbuster design. It is a design that works well > but uses quite a bit of air. You lose most of the energy in the air > by regulating it down to a fairly low pressure before you feed it into > the tube. And you lose a lot more air thru the poorly molded flex joints, probably 5x what comes out the nozzle.
> That's why I went for my extended nozzle design that runs on ~100psi > at the nozzle, with a very small annular jet. A small amount of air > leaves the jet at high velocity and mixes with the surrounding air to > produce a lower velocity column of air at a high flow rate. The > extended nozzle injects coolant into the column at a point where it's > velocity has fallen low enough that it can't atomize the coolant. And I've been cogitating on how to restrict the fluid flow, so haven't made any chips yet. Lack of the ability to bore very fine threads below nominally 10mm discourages me from attempting a needle valve design in some 1/2" thick brass bar I have is driving me toward a pinch the hose idea since the hose is so small anyway, I'm thinking of drilling and tapping into the motor mount, a couple 3mm.7 tapped holes 8mm or so apart, and making a flat piece with matching clearance holes, clamping that teeny hose between them and drawing it down with hex head cap screws to pinch it down to a red hair. Pressurizing the coke bottle takes care of priming the system and I can drill into the mount body to get that air easily enough. It will bleed back out of the bottle, and I can extend the inner nozzle to deliver what liquid does get thru the pinched section to roughly the middle of the annular air running at maybe 10 psi. That way any particulates that get thru the sintered bronze filter on the end of the feed line in the coke bottle will hopefully not be so coarse as to block off the pinched area, AND theres nothing to corrode over time. Might have a cold flow problem with the hose, requiring a pinch adjustment occasionally, but thats to be fiddled with when its encountered. Anybody see any showstoppers?? > By the way Gene, the Chinese misters I linked to previously to have > two tubes to the nozzle, one for air and one for coolant, so you don't > get any leakage at the lock line joints. That's how I manage to run > mine at high pressure. Same here Les, now if we could just get the segmented outer line to hold air. I'm losing 90% of my input air blowing out the sides of the segment joints. Very poorly molded stuff. With a 2hp direct drive AC, its running 75% of the time at 15 psig. I'll burn it up sure as God made little green apples. A 10% duty would be my personal target. Giving it time to cool the cylinder head. Or perhaps put that 6" rotron I bought to put on the vfd, on the compressor instead? Its quiet enough to leave it run full time, and the compressor would last a LOT longer with active cooling full time. The vfd doesn't seem to heat enough to need a fan other than the 3.5" in the box. I left it running at the 7i76D min, set at about 2400 rpm, all night, nothing warm enough to worry about, not even the water the next day. I can set that slower and might but theres only a small torque at that speed anyway. Thanks Les, I appreciate the experience shared. > > Les > > On 21/03/2019 19:43, tom-...@bgp.nu wrote: > > FWIW, here are models of the No Mister Misty: > > > > https://bgp.nu/~tom/pub/NoMisterMisty-Assy.f3d. (Fusion 360 > > Assembly) https://bgp.nu/~tom/pub/NoMisterMisty-Assy.zip (Solid > > Works Assembly) https://bgp.nu/~tom/pub/NoMisterMisty-Assy.step > > (.stp or step file) > > > > -Tom > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
