I've used those hand soaps that have close to a 5:1 ratio of water to
soap in them and when you press down on the top, they produce a soap
foam. I'd like to make a nozzle that does this on a larger scale. I've
seen ones for pressure washers that aspirate the soap into the nozzle,
but I want one that works just like the hand soap one. I want to just
have to force the premixed diluted soap mixture into the nozzle and
have foam come out at a velocity proportional to the input pressure.

Does anyone know how something like that would be designed?

Thanks in advance for any info.

In article .com,
"Bill J." wrote:

Does anyone know how something like that would be designed?

I'm guessing the soap dispenser is a two cylinder pump - one pumps soap
solution, the other pumps air. Perhaps the firefighters among us can
provide details on foam nozzles - I assume those suck air in by venturi
action. I used to use a film washer that did the same thing to inject
bubbles in the column using the force of the incoming water, and it
would foam very nicely if one dropped a drop of photo-flo in the intake.

--
Cats, coffee, chocolate...vices to live by

Go to your local fire dept. and ask to look at their foam generator, if
they have one. That should give you a good idea. It's just a venturi
and aspirator that sucks up the foam/soap solution and blents it with
water and air to make foam.
Bugs

"Bill J." wrote in message
oups.com...
I've used those hand soaps that have close to a 5:1 ratio of water to
soap in them and when you press down on the top, they produce a soap
foam. I'd like to make a nozzle that does this on a larger scale. I've
seen ones for pressure washers that aspirate the soap into the nozzle,
but I want one that works just like the hand soap one. I want to just
have to force the premixed diluted soap mixture into the nozzle and
have foam come out at a velocity proportional to the input pressure.

Does anyone know how something like that would be designed?

Thanks in advance for any info.


Years ago (maybe 20) I had a foam lance attachment for a high
pressure washer, the venturi was on the suction side of the pump
to get the soap into the mix before the lance. The lance had a section
about 150mm long partly filled (90%) with small nylon balls of varying
sizes. The tube probably trebled in diameter at the same time so dropped
the pressure and the mix came out of a fairly large nozzle.

This flocked up the detergent mix and it really hung onto the vehicles
we were cleaning.