Fleck 9100SXT programming question

[brewerbrad]

I'm setting up the subject softener for make-up feedwater for a boiler in a brewery. Unfortunately the documentation is not great and neither is the support from the company we bought it from. Hoping for a little insight from this group.

Here's what I have and know:

Fleck 9100SXT w/ 2 8"x40" resin tanks (capacity of 0.75 cf resin each). I believe that gives me a capacity of 24K grains per tanks based on what I've been able to glean from the web.

Incoming hardness of 4.5 grains

BLFC 0.125 gpm (is this the brine flow rate, both out of and into the brine tank?)
DLFC 0.5 gpm (is this the drain flow rate?)
Injector 00

The unit supposedly came pre-programmed by the seller but there's some things that don't really make sense to me.

The BD (brine draw?) is 60 min and the BF (brine fill) is 12 min. With those numbers, won't it draw 7.5 gallons and only refill 1.5?

That's really my main question, but any advice on timing of the other steps would be appreciated. I did find a well-written step-by-step guide written by a third party online that helped a lot but I'd like to make sure I have it set up properly for my specific situation.

Thanks in advance.

 

[Reach4]

The BD (brine draw?) is 60 min and the BF (brine fill) is 12 min. With those numbers, won't it draw 7.5 gallons and only refill 1.5?

0.5 DLFC is the backwash rate. That seems small to me. I think the injector determines the draw and rinse rates presuming they are significantly less than the DLFC. I am pretty sure the DLFC is in line during the BF time. If that is the case and if we look at the total injector flow, then the DLFC will probably have a significant effect at higher water pressures. I would like to think that while there is still brine, at water pressure above 60 PSI the curves would follow the green lines on the graph, rather than the normal black lines. Drawing markups are my current understanding. I could be wrong.

There is a trade-off between salt efficiency and capacity. 12 minutes of fill will use 6 pounds of salt per cubic ft of resin. That would correspond to BF=6 and C=15.0. That is an efficient setting. Alternatively you could use BF= 8 minutes and C=18.0, which would not be as efficient.

The deal is that the BD time is a combo brine draw and slow rinse. The thing that switches from brine draw to slow rinse is that the brine tank is out of brine. The air check valve keeps the injector from sucking air. The injector continues to pass water that serves as the slow rinse. The slow rinse time is where the salt gets rinsed off of the resin. You can tweak that BD number by sampling the drain water with either taste or TDS meter. The extra saltiness should disappear and the TDS should get close to the TDS of your softened water during the rinse. So you could lengthen or shorten the BD number based on your findings.

I am not a pro.

 

[Sponsor]

 

[Bannerman]

The usual method to program a softener is based on a 1 cu.ft. system, while using a multiplier to adjust for the actual size, in your case, 3/4 cu.ft. Your twin tank unit is actually 2 softeners which alternate from tank to tank while switching to the other tank when capacity has been utilized.

1 cu.ft of resin has a total softening capacity of 32K grains but as some resin will be lost to drain over time due to fracturing, common practice is to calculate total capacity as 30K grains per cu.ft. As your twin tank system each hold 3/4 cu.ft of resin, capacity is calculated as 22,5K grains (30K X .75) each tank.

While the total capacity maybe utilized, salt efficiency would suffer as 15 lbs/salt is required to regenerate 30K grains (1 cu.ft resin), thereby yielding a salt efficiency of only 2,000 grains per pound of salt. This same efficiency for your unit would require 11.25 lbs of salt to regenerate each tank.

Salt efficiency can be substantially increased by setting a reduced usable capacity before a regeneration is triggered. For example, 6 lbs/salt per cu.ft will regenerate 20K grains cu.ft whereas 8 lbs salt per cu.ft will regenerate 24K grains/cu.ft. Salt efficiency for these two settings is 3,333 grains/lb and 3,000 grains/lb respectively. Your corresponding usable capacity settings would be 15K grains or 18K grains using either 4.5 lbs or 6 lbs of salt respectively. Each gallon entering the brine tank will dissolve 3 pounds of salt.

BLFC flow rate governs the water flow into the brine tank but the draw out from the brine tank is controlled by the injector size.

Your stated DLFC number appears too low as I would expect a flow rate of at least 1.5 gpm for a 3/4 cu.ft unit. The DLFC limits the drain flow rate during 'backwash' and 'rapid rinse' cycles.

The brine cycle is a combination brine draw and slow rinse. The usual setting is 60 minutes while the time required to draw all brine is typically completed within 15 minutes. Once the brine tank is near empty, an air check valve (floating ball) closes within the brine pick-up, thereby stopping air from being sucked through the softener from the brine pick-up. The slow rinse continues which pushes the brine through the resin to rinse it away at the flow rate set by the injector.

Edited to add: For a further explanation of brine flow, see dittohead's comments: https://terrylove.com/forums/index.php?threads/disagree-with-fleck-injector-sizing.62213/

 

[ditttohead]

I just finished work for the day (morning) so I am a bit too tired to answer in detail now, but... a quick question. What kind of boiler? Steam, heating hot water, etc.? Howe many gallons of water per day do you use?

Your systems should be set up at 6 pounds of salt per regen (8 pounds per cu. ft.), and the capacity at 18,000 grains in order to maintain some efficiency, but if this is a steam boiler...

The DLFC should be approx. 1.5 gpm depending on water temperature in order to adequately backwash 8" tanks, not sure why they would have put .5 gpm. Actually, I am not even sure .5 is available in a dlfc button by Fleck.

 

[brewerbrad]

Thanks for the replies. Yes, you are all correct, the DLFC is 1.5 gpm. I was out of town and couldn't check and was going by memory, which is obviously faulty.

I think I have a much better understanding of how the system works. Thanks again for the help.

Dittohead, it's a 1.2 MBTU/hr 15 psi steam boiler. It's a closed system. Condensate is returned to the boiler as feedwater, so water usage will be pretty low. Whatever the volume of daily blowdowns and evaporation out of the condensate tank vent add up to (hopefully no leaks!). Maybe 10 gpd? I'll have a much better handle on that when we are in actual production.

I'm more concerned with hardness removal than salt efficiency. I'd guess this thing will go through a regen cycle about once a year at my expected water usage rate. What is the recommended maximum time between regen cycles?

 

[brewerbrad]

Oh, and another question... Should I set the capacity to 18,000 and the safety factor to zero?

 

[Bannerman]

Set capacity to 18K. Set your Fill time to 16 minutes (.125 BLFC X 16 min = 2 gallons X 3lbs/gal = 6 lbs salt).

As it is a dual tank system, no reserve (safety factor) is required as the alternate tank immediately supplies soft water once the initial tank's softening capacity is consumed.

Regeneration should occur at least monthly. Water will always take the path of least resistance so with a regular low flow situation, water will eventually carve a path through the resin thereby bypassing the majority of the resin in the tank (channelling). Hardness can then bleed through even though the softening capacity has not been depleted.

As your softener is small, that may help reduce the potential of channelling but if your flow is as low as you expect, it may continue to occur.

During each regeneration, the resin is redistributed in the tank so you may find that a monthly regeneration is too long and so more frequent regenerations are necessary.

Is there any other areas in the brewery that could be fed from the softener? Higher flows can help reduce some effects of channelling. What about the water utilized for cleaning the kettles?

 

[ditttohead]

Since it is a steam boiler you will want to maintain less than 2 ppm hardness so efficiency can be thrown out the window. Considering the low water use it is not anything to worry about.

Set the system to 20,000 grains, brine draw to 80 minutes, and the brine fill to 12 pounds of salt per regeneration (32 minutes). You will also want to set the reserve to 0 and the day override to 28 days. Watch the water use for the first few days and make sure the system maintains soft water when the meter starts to near zero. Get a proper test kit.
http://www.hach.com/total-hardness-test-kit-model-ha-71a/product?id=7640219507&callback=pf

 

[brewerbrad]

Thanks again for all the help!