Best way to control pump for SS low pressure functions...

[DavidM]

I am planning to move away from the the traditional low pressure tank and flojet system to an injector system (hydraflex style). The piece of the puzzle that I am missing is how to control the single pump. One pump will provide the water for all low pressure functions in all five bays.
I have a Ginsan pump stand, each low pressure function opens a 24v solenoid for the air and a solenoid for the liquid.

I think I need a way to activate a single output to start the pump when any one or more of the 25 (5 low pressure functions x 5 bays) different functions are selected.

Hopefully that is clear. What is the best way to accomplish this?

David

 

[cantbreak80]

Provide city water supply to a water pressure regulator set to 10psi

Regulator out to concentrate Injector In

Injector Out to FloJet In

Flojet Out to Solenoid manifold In

Solenoid Outs to bays

Set the Flojet operating pressure to satisfy your desired delivery volume.
You’ll need to duplicate this setup for each product delivered.

Here’s an example of a reliable and compact pressure regulator that can be used for water or air.
https://www.kleen-ritecorp.com/p-1682-norgren-r06-221-nnka-mini-regulator-airwater-w-filter-14.aspx

 

[MEP001]

Have you thought about using a Dosatron or a Dema Mix-Rite instead? All you need is water supply, injection pump, soap and solenoids.

 

[DavidM]

Thanks for the suggestions but neither will accomplish everything that I am looking for.

Currently, I am thinking that I may be able to use a pressure switch like this... http://www.automationdirect.com/adc...sure_Sensors/Pressure_Switches/MPS25-1C-P200A

When the solenoid opens and the pressure drops it will start the pump. I plan to use a 10 GPM Sta-Rite booster pump that can provide 200 PSI to the injectors. That single pump will supply foam brush, presoak, tire cleaner, bug remover and triple foam.

I believe it will provide a much better customer experience in the bays.

 

[MEP001]

I don't think that's a particularly good idea, because the pump will have to start and stop like crazy to try and maintain pressure unless there's a bladder tank, and I doubt there are any bladder tanks of the volume you'd need that can handle 200 PSI.

A more expensive option would be a VFD-controlled pump and motor with a pressure transducer. It would run the pump only at the RPM needed to maintain your set pressure. I know you can get a ready-made system that you just mount, plumb and plug in.

The cheapest, simplest thing I can think of would be to take an MX-8 and just run timed load from each bay to it and have the pump run whenever a bay timer is running. It wouldn't be particularly efficient and you'd need some way for that pumped water to not get hot as it circulates without getting used. Or maybe just a bank of 25 relays, would take some time to wire up but an Omron SPST relay with base from Mouser might be about $5 each in that quantity.

 

[cantbreak80]

Oh, I misunderstood your initial question.

I agree with MEP001's concerns and believe you're maybe creating a future nightmare. My biggest concern…should the pump and/or control system fail, every LP system at the car wash ceases to work.

Your pressure switch idea should work. However, to prevent rapid cycling of the pump, you should use a wide differential pressure switch instead.

 

[Earl Weiss]

My thoughts are as follows.
1. Why 200 PSI for low pressure functions? I have tunnels with "Surge Tank Systems and the pump is set to maintain 60 PSI which is plenty for the tunnel. Their is a bladder tank with pressure switch.

2. How do you think this will improve the customer experience?

3. Wondering about stress on poly lines and fittings at 200 PSI.

 

[WikiWash]

With the hydraflex injectors they need a 200 psi supply on the influent side of the injector to create the venturi effect, in which corresponds with their dilution ratio charts. On the effluent side it turns out to be more around <60 psi.

 

[MEP001]

Correct me if I'm wrong, but doesn't the flow rate through an injector change how much chemical it draws?

 

[WikiWash]

It depends on the size of the hydraflex injector they all have different size orifices. Their injectors range from 0.25 gpm to 5.5 gpm. Here is a link for my info http://hydraflexinc.com/products/chemical-injectors/chem-flex-injectors scroll down and click on "chem-flex product literature"

 

[getnbusy]

I can't seem to envision how 1 pump would work for all features in all bays. I have thought of doing what I believe the same thing but I envision it to have a pump and manifold setup for each product. Kinda like a laserwash 4000 chemical pump and manifold for each product. Or a setup for each bay. I think that would be awesome and most definitely enhance customer experience with better flow and waay faster changeover times

 

[wash4me]

I can't seem to envision how 1 pump would work for all features in all bays. I have thought of doing what I believe the same thing but I envision it to have a pump and manifold setup for each product. Kinda like a laserwash 4000 chemical pump and manifold for each product. Or a setup for each bay. I think that would be awesome and most definitely enhance customer experience with better flow and waay faster changeover times

I would put a three-phase sta-rite pump in and have it run one minute past the last call for pressure. This would keep it from short cycling so much and a 3-phase motor will take a lot more abuse.

 

[Earl Weiss]

Correct me if I'm wrong, but doesn't the flow rate through an injector change how much chemical it draws?

Why wouldn't it be he same as a hydrominder venturi? The volume would change, but within certain operational parameters the ratio should remain constant..

 

[MEP001]

You're right, which is my concern. When a Hydrominder fill valve isn't working right and only fills at about 1/4 normal rate, it draws no chemical at all. I don't know if the OP plans to have one injector per function per bay or just one injector for tire, one for presoak, etc., but if it's the latter he's not going to draw enough soap with just one bay running if it can flow enough for five.

 

[Earl Weiss]

You're right, which is my concern. When a Hydrominder fill valve isn't working right and only fills at about 1/4 normal rate, it draws no chemical at all. I don't know if the OP plans to have one injector per function per bay or just one injector for tire, one for presoak, etc., but if it's the latter he's not going to draw enough soap with just one bay running if it can flow enough for five.

I see your point. Have yet to see how this may improve the customer experience. Plus I have seen how some hydra Flex setups are made to have a standby pressure pump in case one fails. Seems easier to have a spare flo Jet and hydrominder / rebuild kit.

 

[MEP001]

My guess would be that the OP is going for an alternative method of using the high-pressure pump to deliver all the functions to the bay, probably just to cut down on the number of things to have problems.

 

[DavidM]

Sorry for being out of the conversation for so long. Wikiwash has it right, 200 psi to the injector, pressure after the injector is substantially lower.

It is the same principal that is used on the Laserwash for decades and has become fairly common in tunnels as well. Tom Hoffman Jr has used it in his self serve bays. He has some videos on youtube that show it working. He used the system offered by Hydraflex.

Each bay would have a bank of injectors, one injector per function per bay. No injector would be shared between bays.

Advantages in the bays - Even pressure (Flojets tend to pulse), better, more consistent mixing of chemistry, depending on setup can offer a much better foam show, potentially faster change over times.

Benefit to us - no holding tanks, one very reliable pump rather than 3-8 individual pumps, easier adjustments to dilution ratios

Biggest potential downside is that one pump failure will wipe out all low pressure functions. Can be solved with a backup pump (somewhat expensive but I already have one). These pumps are far more reliable than most other pumps currently used for low pressure functions.

I plan to set it up for one bay and test it. I think controlling the pump speed with a PLC would be ideal but that may be beyond my skill set.

David

 

[CarWashBoy]

You might try a VFD on each motor, and run it through your hi pressure pumps. Works perfect.. Eliminates all your low pressure lines..
Doug..

 

[Earl Weiss]

......... pressure after the injector is substantially lower.


Each bay would have a bank of injectors, one injector per function per bay. No injector would be shared between bays.

Advantages in the bays - Even pressure (Flojets tend to pulse), better, more consistent mixing of chemistry, depending on setup can offer a much better foam show, potentially faster change over times.

Benefit to us - no holding tanks, one very reliable pump rather than 3-8 individual pumps, easier adjustments to dilution ratios

David

I need enlightenment;


1. >> one injector per function per bay.<< So, with 4 LP functions and 6 bays that is 24 injectors vs 4 flo jets and 4 hydrominders & Tanks and this is simpler because?

2. >>Even pressure (Flojets tend to pulse)<< Like to hear from others. Due to volume FJ produces vs the .05 nozzle this is not something I experience at the bay.

3. >> more consistent mixing of chemistry<< This is a function of water pressure and can be solved with a pump to a hydrominder, injector bank for any holding tank.

4. >>much better foam show<< Don't see how. This is function of air and solution mixing, not dilution from whatever system. Enlighten me please.

5. >>potentially faster change over times<< How? Solution line is full with check valve T'd above boom either way.

6. >>easier adjustments to dilution ratios<< 24 injectors versus 4 with anohter system and it''s easier to change injectors than 4 hydrominder tips? Injector pumps? Dosatron?

 

[MEP001]

2. >>Even pressure (Flojets tend to pulse)<< Like to hear from others. Due to volume FJ produces vs the .05 nozzle this is not something I experience at the bay.

I've also never seen an issue with the pulse of the Flojet affecting anything in the bay at all, although I've never set up or worked on a wash that has a Flojet for liquid supply without air mixed with it.