Bob You say adding a 3stage vac motor as I suggested would not increase the airflow, I would agree with this if the Bane blower was already pulling the maximum of air allowable through the 2inch restriction, but it does'nt so there is lots of 'space' to allow more air to through.
Mike - With both blowers pulling through the same 2" opening coming from the recovery tank, it is almost the same as one of the blowers discharging into the inlet of the other blower. It may increase the CFM a little, but if you were to add another 2" pipe into the Bane vacuum tank, and put a separate blower on that 2" pipe, now you have 2 -2" pipes pulling air SEPARATELY from the tank, which will definitely increase airflow, and rise time, at the wand when cleaning. This works best, however, if both vacuum motors are the same, so they work together, or in balance.
Our "wind tunnel tests" indicated that even with 2 separate stacks, if the vacuum motors weren't balanced, extra turbulance was noticed within the vacuum tank, which may not be a big deal , but every "polished stone" will move the water faster within a vacuum system.
An easier way to add vacuum to any existing vacuum system, portable or truckmount, and to not have to match vacuum blowers within the existing system, is to add an inline vacuum booster, parallel to the Bane 2" vacuum hose. This way the booster is pulling into the booster tank through it's own 2" vac port, along with the Bane pulling into the 2" outlet vac port of the booster. This will give you much more CFM airflow, lift, and water recovery at the wand. Most important point here is that now the Bane is more of an assist vacuum to the booster, as the booster is mostly affecting the wand, assisted by the Bane. The Bane is now adding vac power, and removing water from the booster.
as for this set-up increasing lift, if this was so would'nt the vac gauge read higher? I believe it does'nt increase the Lift because the wand/carpet interface causes a vacuum build-up in the recovery tank, this vacuum puts too much strain of the small motor of the 3 stage vac so stops it actually pulling any air at all, I've put my hand against the outlet of a 3stage vac set-up with a bane blower and if you block off the waste tank inlet evntually no air is blowing out of the 3 stage.
The vac gauge doesn't read higher because the vac you added isn't able to increase the lift already existing at the point where it is located. Put that same vac motor into a booster setup, and locate it closer to the wand, and you'll probably double your CFM, and add to the lift of the vacuum system overall to boot, as you don't have to overcome as much friction loss from hose length, with a booster located 50' from the cleaning wand.
this is why I think the most important thing to remember with the set up I've suggested is correct use of the wand to allow a continuous flow of air.
Wand technique does play a role in water recovery. When I clean, I lift the wand at the end of the backward stroke before I start the forward stroke again. This supercharges the airflow from the vacuum tank, and depending on the rise time of the vacuum system, will move a lot of air back towards the recovery tank before you can drop the wand to the carpet for the next forward stroke.
Wand design also makes a difference. The jury is still out on that one for me, although I do think there is some merit in the wand/carpet interface design, and dealing with it better. I have been experimenting with a few different things in this regard.
HTH.
Best regards,
Bob Savage
SAVAGE-1 truckmounts
