Friday, September 26, 2014

Increase Commercial Water Softener Efficiency With a Twenty Dollar Part

On a recent sales call to a local dialysis clinic, the biomedical technician complained about a distinct loss of capacity in his water softener. Asking the typical diagnostic questions, such as resin age, brine system inspection, the Bio Med told me they recently upgraded their Reverse Osmosis machine and they are using considerably more water. End of story correct; more water used, more regenerations required? Well No. We ran the numbers and still concluded he was regenerating the softener too often. Something else was wrong.
 
Tank X-RAY
I had one last trick up my sleeve. “The Tank X-Ray”. Yes, folks, you can X-Ray a softener tank with a 500 watt halogen work light as sold in many home improvement stores. The X-Ray process is easy; you darken the room, turn on the light, and press it against the upper 1/2 of the tank. Now, this only works with a natural color fiberglass mineral tank. The bright light will not penetrate a painted tank. The light will let you gaze at the insides of the tank. Everything will appear as shadows.
 
What we discovered here was the resin beads were all bunched up to one side of the tank. NOT GOOD. The resin should appear as an even, level, dark line across the whole diameter of the tank. AH HA! This tank was suffering from a little known chronic problem called “Diffusion Exclusion”. Someone forgot to include the Inlet Diffuser/Disperser. The inlet diffuser is an option offered with the new control valve that regulates the resin regeneration process. This small critical part is often discarded as unidentifiable.
Pentair Fleck 2859 Valve Without Inlet Diffuser/Disperser  Installed
 
Don't Throw Away the Plastic Inlet Diffuser/Disperser on Left!
 
Penatir Fleck 19608-15 Inlet Diffuser/Disperser Installed on Pentair Fleck 2850 Valve
The inlet diffuser is attached to the underside of the control valve during tank assembly. Its main purpose it to diffuse the path of the water flowing into the resin bed during the DOWN FLOW service cycle. The diffuser forces the water evenly outside, then down. Without the diffuser, the water path is straight down. The result is a drilling effect. The drilling gets worse as the flow increases.
 
Two bad things happen:
  1. The resin is usually blasted and gets bunched up.
  2. You lose efficiency at high flow because the water isn't flowing evenly through the resin bed, it's drilling past it. 

In Conclusion:
Avoid Tank Turmoil. X-Ray your tank. It’s actually fun to do. Even more fun is to start your softener into a regeneration cycle and watch your resin expand upward during backwash and float around like lava, then see it settle down during the rinse cycles.
 
For More Information:
To Buy Fleck Valve Parts Use Our Interactive Drawings
Links to Industrial and Commercial Water Softener information and bulletins
Pentair Fleck 2750 Valve Service Manual
Pentair Fleck 2850 Valve Service Manual
Pentair Fleck 2900S Valve Service Manual

Friday, September 12, 2014

How Biofilms Form on Surfaces By Swimming Cells

In a very interesting article by Medical Design Technology titled "Findings Suggest How Swimming Cells Form Biofilms on Surfaces", scientists at Purdue University’s School of Mechanical Engineering modeled how biofilms actually draw swimming bacteria to the film and how bacterial colonies to thrive on surfaces.  It is interesting how the same mechanism which causes fouling of implantable medical devices, fouls our UPW distribution systems, industrial pipes and boat propellers. 

This model confirms what we see in the field that once a biofilm takes hold, the problem seems to accelerate in severity. This is why Res-Kem recommends routine sanitizations of water treatment distribution systems to remove biofilms.

For More Information:
To schedule a system sanitization
To purchase the research paper titled "Effect of solid boundaries on swimming dynamics of microorganisms in a viscoelastic fluid" by G. -J. Li, A. Karimi, A. M. Ardekani  in the Rheologica Acta, published on Aug. 31, 2014