Commercial and industrial water softeners can be designed to function in a variety of flow patterns. Designs generally fall into one of two categories: "co-current flow" or "counter-current flow." Softeners can also be built in a "contained bed" arrangement without backwashing, or for "free-board backwash expansion operation."
How many designs of cation water softeners?
Let’s look at the various designs of cationic water softeners.
1- Co-current flow
The most often utilized design in industrial-size water softeners is co-current flow (or down flow). In this procedure, the brine solution and the softened water both flow downwards, through the cation resin bed in order to complete regeneration, i.e., a system in which both streams travel vertically through the bed.
In addition to offering the full backwash step to expand the bed for thorough cleaning, when the softener is handling problematic water supplies, such as those containing turbidity and precipitated iron, the co-current design also calls for less complicated master control valving.
Additionally, the fresh water zone is passed through and subsequently displaced by the brine solution, in the co-current method of regeneration, reducing the strength of the entering brine at the start of the regeneration step. As a result, at the lower salt concentrations (3-5 lbs. NaCl/cu ft.), the bottom layer of the cation resin bed only slightly regenerates. Accordingly, some hardness leakage may happen when the softener resumes (down-flow) duty.
2- Cross-current Flow
The second way of operation, known as counter-current flow, involves softening downwards through the cation resin and brining upwards through the bed, with the service flow going in the opposite direction. This technique, sometimes known as "up-flow brining," has a number of advantages.
For optimal recharge, the strong, less diluted brine solution contacts the lowest area of the resin bed, right away in this mode. The amount of resin bed recharging varies depending on salt dosage level (lbs./NaCl/cu. ft.) and associated water hardness.
Working of cross-current flow cationic water softeners
1: The bottom bed zone is always in the most fully regenerated sodium (Na) or potassium (K) form, making the counter-flow brining process particularly successful in low salt dosage (3-5 lbs/cu ft.) demand-regenerated units.
2: In this counter-current mode, the water exiting the softener tank flows via the patch of resin that has been most thoroughly rejuvenated last, ensuring maximum softening with relatively little hardness leakage.
3: It takes particular hydraulic engineering measures to retain the cation resin bed in a fixed position, during brining in order to achieve effective regeneration and capacity with the counter-current approach.
4: Brine the resin bed before backwashing is one way to achieve this. In this manner, the down flow service run compacts the cation resin bed, making "fluidization" less likely.
5: In order to completely separate the hardness ions from the cation resin itself, the exchanger beads must be thoroughly in touch with and penetrated by the brine solution, which is prevented by a fluidized bed.
6: The last "quick rinse," which efficiently removes any remnant salt brine from the resin bed, before putting the unit back in service, is a crucial stage in the effective regeneration of all water softeners.
3- Industrial Counter-current Water Softeners
This resin bed fixing in big industrial cationic water softeners can be accomplished using compressed air, a second water stream block, or the placement of low-density inert plastic granules, above the cation bed.
Each design must have the appropriate internal distribution piping systems, in order to achieve the maximum operating performance and capacity, of a concurrent flow water softener or a counter-current flow water softener. The use of a gravel sub fill will nevertheless easily improve the more uniform distribution of backwash water, or brine solution throughout the lower face of the resin bed, despite the fact that it is no longer common in small water softeners.
To achieve this more even distribution, numerous lower plastic distributor-collectors, have recently undergone reconfiguration. Similar to co-current systems, less dilution in the freshwater zone is caused by introducing the strong brine solution, closer to the top of the resin bed. This method can result in both more effective salt consumption and a higher regeneration power, resulting in less wastewater.
4- Twin-tank Water Softeners
The alternating twin-tank method is another distinctive idea, in the construction of commercial and industrial water softeners. In this system, the cationic water softening is carried out using two similar softener tanks, and when a specified exhaustion threshold is reached, a master control mechanism automatically shifts from tank to tank.
While, the other is pulled out of service and regenerates for standby status, each tank assumes responsibility for supplying a constant supply of softened water. Either meter/nonelectric controlled or meter/electric-regenerated systems, operate these twin-tank softening units.
Benefits of twin-tank water softeners
1: This kind of technology provides continuously softened water, conveniently accommodating irregular flow requirements.
2: Another benefit is that no hardness or iron enters the brine-saturator unit, due to the constant conditioning and softening of the brine makeup water.
3: The admission of solely softened, conditioned water for backwash and rinse into either softener tank, once the twin-tank system is operational is a third characteristic. This feature prevents precipitated iron from contaminating the cation resin bed, and eliminates any hardness carryover if present in the raw water.
Water Softener manufacturer
Netsol Water specializes in offering effective water and wastewater treatment solutions, including water softeners for commercial and industrial purposes. We work hard to give businesses high-quality, dependable solutions.
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