Intellichem flow cell installation question...

[muski]

I'm installing an Intellichem system for automated liquid chlorine dispensing. Although I purchased a two-pump Intellichem system, I haven't purchased an acid container system yet -- I think my PH is pretty stable, and am hoping not to need it. I have to admit I am a little nervous about having a system that injects these two chemicals into one pipe. However, I'd like to have the option to add acid in the future, if needed.

I'm trying to figure out where to install the flow cell and the injection points. After my filter I have about 8" of pipe, then a T-connector to my booster pump, then a Flovis Flowmeter, then about another 8" of pipe before my solar valve. I use the Flowmeter to see how much water is going to my solar panels. It also is a check valve.

Questions:

Unless I replumb, I only have room for two ports each on the sections of pipe on either side of the T-to-booster/flowmeter. So, I'm wondering which combination (if any) is the right one...

Option 1) Filter -> flow cell inlet -> flow cell outlet -> T to booster -> Flow meter -> acid feed -> chlorine feed -> solar valve

I'm guessing having the flow cell inlet and outlet only separated by a few inches won't have enough pressure diff to maintain flow through the cell. So, I could put the flow cell outlet after the booster-pump T-connector and the flow meter -- given the outflow to the booster pump, perhaps this is enough of a pressure diff? Then where do I put the chlorine feed (and, possibly later, the acid feed)?

Option 2) Filter -> flow cell inlet -> acid feed -> T to booster -> Flow meter -> flow cell outlet -> chlorine feed -> solar valve
Is it ok to to feed acid before the flow cell outlet? Could the elevated acid concentration damage the flow meter or the booster pump?

or, swapping the acid and chlorine feeds...

Option 3) Filter -> flow cell inlet -> chlorine feed -> T to booster -> Flow meter -> flow cell outlet -> acid feed -> solar valve
Similar question -- is it ok to to feed chlorine before the flow cell outlet? Could the elevated chlorine concentration damage the flow meter or the booster pump?

Or do I really need to replumb to have one port on one section and three on the other?
Option 4) Filter -> flow cell inlet -> T to booster -> Flow meter -> flow cell outlet -> chlorine feed -> acid feed ->solar valve

or do I have to have the acid feed before the chlorine feed (as the manual shows)?
Option 5) Filter -> flow cell inlet -> T to booster -> Flow meter -> flow cell outlet -> acid feed -> chlorine feed ->solar valve

Which options are acceptable/best?

Thanks!

P.S. FWIW, my system has two external Stenner pumps, not the ones integrated to the side of the Intellichem.

 

[muski]

So I spoke to Pentair tech support, and they suggested that option 2 is acceptable. So I installed it all, but now I'm having trouble with my flow cell...

The Intellichem manual suggests putting the inlet line just after the filter and the outlet line after the heater -- guessing this is to create a pressure differential. But I don't have a heater, just solar... So I installed my inlet line just after the filter and installed my outlet line after the T-connection to my booster pump and a Flovis flowmeter. They're about 15" apart (see photo).

[attachment=0:3mczv5ka]Untitled.jpg[/attachment:3mczv5ka]

But, I'm getting a no flow fault on the Intellichem panel (and noticed that it filled very slow on startup). I was hoping it would work at the 1250rpm speed I like to run my pump (or even 1850rpm for solar). I tried my high speed setting (2350rpm), but even that wasn't enough to get the flow going. I did check for blockage by unplugging the outlet port and letting it run into a bucket -- plenty of flow even at low rpm.

Any ideas how to increase the flow to the flow cell? Would lower the flow cell help? Or making the tubing on one side longer than the other? Or use thinner 1/4" tubing on one side? The manual says not to plumb the outlet before the main pump line as too much vacuum could damage the sensors.

Also, I'd like this work even at 1250rpm -- seems silly to run the pump faster just to make the flow cell work.

Any suggestions welcome.

Thanks!

 

[Bama Rambler]

The problem is that you don't have enough pressure drop across the flow meter to divert enough flow through the Intellichem.

You could add a valve between the inlet and outlet that you could adjust to get enough pressure drop or you could add a union and make an orifice plate to go in it to reduce the flow. It's also possible that you could add a 2 psi spring loaded check valve between the inlet and outlet.

 

[muski]

In the end the Pentair tech rep suggested that I plumb the flow cell outlet before the pump, and then partially close the outlet valve to make sure I don't have a vacuum in the chamber that could damage the sensors. So I closed the outlet valvle until the flow magnet just barely closed the circuit with my pump at the lowest speed I use. I also put a pressure meter in the bottom port and could see that I wasn't creating a vacuum. With my pump at 1250rpm there was 1psi in the chamber. At 1850rpm it's about 3psi and at 2350rpm it's about 5 psi.

The only problem I have is priming when I have partially drained the system. The pump fails to prime (and generates an alert) unless I manually close all the valves to the flow cell. But I guess I can live with this.

Later, I was able to re-use my original outlet hole for the chlorine outlet (not visible in these photos).

Here you can see the inlet/outlet plumbing
[attachment=2:3w3cd3yj]IMG_0027.jpg[/attachment:3w3cd3yj]
Note the partially closed outlet valve. The pump is running at 1250rpm.
[attachment=1:3w3cd3yj]IMG_0028.jpg[/attachment:3w3cd3yj]
Here's the pressure at 1850rpm when my solar panels are running.
[attachment=0:3w3cd3yj]IMG_0029.jpg[/attachment:3w3cd3yj]

 

[Bama Rambler]

That works, but it's not an ideal solution. Glad you got it working though.