Double tank double valve water softener

Product Details

1、 Principle of scale removal by water softener

A water softener uses ion exchange technology to exchange functional ions on resin with calcium and magnesium ions in water, thereby adsorbing excess calcium and magnesium ions in water and achieving the goal of removing scale (calcium carbonate or magnesium carbonate).

The water softener is equipped with a softener resin. This artificial ion exchange resin contains soft mineral sodium, which can undergo ion exchange reactions with hard minerals such as calcium and magnesium dissolved in water. Sodium does not accumulate on the surface of objects in the form of scale, so it poses little harm to objects in contact with it.

Resin is a porous, insoluble exchange material. When the resin is in a newly formed state, these charge exchange sites are occupied by positively charged sodium ions.

2、 Resin regeneration

Resin preferentially binds cations with stronger charges, with calcium and magnesium ions having stronger charges than sodium ions. When water containing calcium and magnesium ions passes through the resin storage tank, calcium and magnesium ions come into contact with resin beads and replace sodium ions at the exchange position. After ion exchange, calcium and magnesium ions are adsorbed on the resin inside the water softener, and the water flowing out becomes softer.

Finally, after all resins are fully adsorbed with calcium and magnesium ions, they can no longer work and require regeneration treatment. The regeneration of water softener resin is carried out using a dilute solution of sodium chloride and water.

During the regeneration process, the working water flow of the water softener is first stopped, and the saltwater drawn out from the saltwater tank is mixed with another diluted water flow. The diluted saltwater solution flows through the resin and comes into contact with the resin containing calcium and magnesium ions. Although calcium and magnesium ions carry stronger electrical charges than sodium ions, concentrated salt solutions contain millions of sodium ions with weaker charges, which have the ability to replace fewer orders of calcium and magnesium ions. In this way, when calcium and magnesium ions are replaced and exchanged, the resin is regenerated, preparing for the next softening process, and so on.

3、 Operation process of general control valve for single valve and single tank of softened water equipment

If RNa represents sodium resin, the exchange process is as follows:

2RNa+Ca2+=R2Ca+2Na+

2RNa+Mg2+=R2Mg+2Na+

After passing through the sodium ion exchanger, Ca+and Mg+in the water are replaced with Na+.

The operation process of a single valve and single tank control valve for softened water equipment is generally as follows: operation, backwashing, salt suction, slow washing, salt tank replenishment, and forward washing.

All processes of different softening water equipment are very similar, but there may be some additional processes due to differences in actual processes or control needs. Any softening water equipment based on sodium ion exchange is developed on the basis of these five processes (among which, the fully automatic softening water equipment will increase the saltwater re injection process).

Backwash diagram of softened water equipment workflow: After a period of operation, the equipment will intercept a lot of dirt brought by the raw water on the resin upper part. After removing these dirt, the ion exchange resin can be fully exposed, and the regeneration effect can be guaranteed. The backwashing process is when water is washed in from the bottom of the resin and out from the top, which can wash away the dirt intercepted at the top. This process usually takes about 5-15 minutes. Salt absorption (regeneration): The process of injecting salt water into a resin tank. Traditional equipment uses a pump to inject salt water, while fully automatic equipment uses a dedicated built-in sprayer to suck in salt water (as long as the inlet water has a certain pressure).

In practical work, the regeneration effect of salt water flowing through the resin at a slower speed is better than simply soaking the resin in salt water. Therefore, softened water equipment adopts the method of slow flow of salt water through the resin for regeneration. This process generally takes about 30 minutes, and the actual time is affected by the amount of salt used. Slow flushing (displacement): After flowing through the resin with salt water, the process of slowly flushing all the salt in the resin with raw water at the same flow rate is called slow flushing. Due to the fact that a large number of calcium and magnesium ions on the functional groups are still exchanged by sodium ions during this flushing process, according to practical experience, this process is the main process of regeneration. Therefore, many people call this process displacement. This process is generally the same as the salt absorption time, which is about 30 minutes.

Quick flushing: In order to thoroughly flush away residual salt, a flow rate similar to actual work should be used to flush the resin with raw water. The final effluent of this process should be soft water that meets the standard. Generally, the fast flushing process takes 5-15 minutes.