EFI fuel pump and water.

[Chris Conlon]

The reason I found that page was that I was specifically thinking
of using ultrasonic evap for water injection. I wanted the
ability to finely modulate water flow, also the physical layout
worked very well in my intended app. Particle size can be super
small... maybe too small for WI use.

The main problem is the mass flow rate needed, it's pretty high by
small evaporator standards. Such units do exist, and could even fit,
my application is the bottom of a deep plenum, ~13" x ~6" at the
floor.

The problem is the power drain, something like 30W for 1 lb/hr,
and the cost of the ultrasonic heads. (You'd need a bank of several
to hit those flow rates.)  You could run them off of 12v, since
there has to be a converter anyway; the transducers run 50-100W,
in the range of 1-4 MHz. Yes megahertz, a few range as low as
800 KHz. It would be instant on, also flow rate is very easy to
modulate over a wide range, and the setup is lightweight.

I had a nice long talk with an engineer at one of the transducer
manufacturers, after which I dropped the idea. (Might pick it
back up as a supplemental system tho.) The best bet for those
seriously interested is to crack open the wallet and get a
bunch of the commercially available ultrasonic mister nozzles.

At 03:31 PM 7/13/00 -0400, Bruce Plecan wrote:

>On say a small engine like a stockish GN (3.8L v-6).
>Has 6,  30lb/hr injectors.   180 lbs/hr fuel.  Figure 6 lbs per gal, so
>that's 30 gals per hour of fuel, and SHR meantions 1/2 to 2/3 fuel via vol
>as I recall (anyway I've used the 1:2 several times and it was right).  So
>we need at least 15 gals per hour, for a stockish engine.
>
> [snips]
>
>12v
>realitively light
>instant on for massive water
>Grumpy
>
>
>> I'll guess that it's got a 2 gal tank, that lasts about 8 hours, so it
>> makes mist at a rate of .25 gal/hr.  It's manufactured by Holmes.  This
>> is one that plugs in, not one that attaches to your A/C system.
>> Is this interesting?
>>
>> Chris Conlon wrote:
>> > A while back while looking for ultrasonic evaporators, I found this:
>> > http://www.dghsys.com/DEFAULT.HTM

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