Liquidator chemistry

[stev32k]

I'm wondering if anyone has worked out the liquidator chemistry? I assume that the hypochlorite is being converted to hypochlorus acid which diffuses into the water above the hypochorite level. I also assume that equilibrium is reached between the concentrated hypochlorite on the bottom and the saturated hypochlorus acid solution above.

The reason I'm asking is that if the above is true then it should not make any difference what strength chlorine solution is used. The same amount of hypochlorus acid would be delivered (assuming constant flow) regardless of the strength of the chlorinating solution. The difference would be that using a 10% or 12% bleach would last longer than using 6%. Is that right or am I missing something?

 

[stev32k]

Since I didn't get a response here I called HASA to ask them the question and they put me in touch with the guy that designed the liquidator. Turns out I was wrong and the strength of the chlorine solution used does make a difference. He said the required flow rate from the liquidator would vary based on the % chlorine used. Using 6% bleach would require either a higher flow rate or a longer run time (maybe both) than a 12% solution. He recommended using no less than a 10% chlorine solution and 12% was even better. If one used 6% bleach he said the best thing to do was have the flow wide open and vary the run times until you got the concentration needed.

 

[chem geek]

Sorry I didn't see this sooner, but glad you got your answer. The hypochlorite diffuses from the concentrated solution into the pool water layer above it and that pool water layer is NOT saturated with hypochlorous acid -- it's higher in FC than the bulk pool water, but much lower than the concentrated hypochlorite solution (which is tens of thousands of ppm FC). The rate of diffusion (in an absolute sense) is proportional to concentration so one would expect needing around twice the water flow rate to output the same amount of chlorine from 6% compared to 12%.

 

[Z06Boricua]

Sorry I didn't see this sooner, but glad you got your answer. The hypochlorite diffuses from the concentrated solution into the pool water layer above it and that pool water layer is NOT saturated with hypochlorous acid -- it's higher in FC than the bulk pool water, but much lower than the concentrated hypochlorite solution (which is tens of thousands of ppm FC). The rate of diffusion (in an absolute sense) is proportional to concentration so one would expect needing around twice the water flow rate to output the same amount of chlorine from 6% compared to 12%.

Is it safe to assume that twice the water flow rate would result in the stored chlorine depleting in about half the time requiring more frequent refills of the liquidator? I recently switched form 6% to 10.5% and I'm wondering if it would be worth trying to find 12% somewhere nearby.

Jose

 

[stev32k]

I also learned that if it sets for 2 or 3 days without use the chlorine strength of the water above the bleach layer will increase significantly and you have to reduce the flow rate.

Overall if I had to do it over I would definitely go with a fixed rate peristaltic pump and a timer. It would be more trouble and a little more cost up front, but I believe it would be worth the effort. A 15 gallon container of 10.5% chlorinating solution would last 20 to 30 days in place of the 6 to 8 days with the liquidator. I also believe the dosing would be more uniform and predictable. So far I have a little over $300 invested in the liquidator and that is almost as much as it would cost to install a pump and timer.

 

[linen]

A 15 gallon container of 10.5% chlorinating solution would last 20 to 30 days in place of the 6 to 8 days with the liquidator.

I am not experienced with a liquidator, but I think your statement above is incorrect. You would still use a similar amount of chlorine, regardless of the delivery method.

 

[stev32k]

A 15 gallon container of 10.5% chlorinating solution would last 20 to 30 days in place of the 6 to 8 days with the liquidator.

I am not experienced with a liquidator, but I think your statement above is incorrect. You would still use a similar amount of chlorine, regardless of the delivery method.

I did not mean to imply I would use less chlorine. The use rate would be the same. The period of time between adding chlorine to the feed tank would be extended because it holds more volume of bleach not because the use would decrease.

 

[linen]

Yep...I am inexperienced with the liquidator...I understand what your saying now

 

[chem geek]

Certainly using a higher concentration of chlorine would have you replace the chlorine in The Liquidator less frequently in proportion to its concentration. This assumes you set The Liquidator flow rate to produce the same FC per day delivery rate and that your pool's chlorine demand is fairly constant.