Understanding the Operation of a Water Softening Filter

Water Softening Filter

The so-called “water softening filter” can also be called a “water softening device”. Its function can be understood from its name. The main filler of the water softening device is resin, which is used to remove calcium and magnesium ions from water and soften the water quality. The device can be used alone or as a pretreatment device for the reverse osmosis treatment process. 

The overall working process of the water softening device can be divided into four processes: backwashing, salt absorption (regeneration), slow rinsing (exchange), and fast rinsing. The different equipment processes are very similar, but sometimes there are some additional processes due to the different actual processes or control needs.


After the backwashing equipment works for a long time, the pollutants intercepted by the upper part of the resin will be more. These are brought by raw water. To remove these pollutants, the ion exchange resin must be fully exposed so that regeneration can be achieved. The backwashing process is to wash water into the bottom of the resin and flow out from the top, washing away the pollutants intercepted at the top. The entire process takes about 5-15 minutes.

Salt Absorption (Regeneration)

This is the process of injecting salt water into the resin tank. Traditional equipment often uses a salt pump to inject salt water, while our fully automatic equipment uses a dedicated built-in injector to suck in salt water. In the actual working process, the regeneration effect is better when the salt water flows through the resin at a slower speed than when the resin is simply soaked in salt water. Therefore, water softening devices use the method of slowing salt water flow through the resin for regeneration, which takes about 30 minutes.

Salt Absorption Regeneration

Slow Rinsing (Exchange)

After the resin flows with salt water, the salt in the resin is slowly rinsed out at the same flow rate. This process is called slow rinsing. Since a large amount of calcium and magnesium ions on the functional groups are exchanged with sodium ions during this rinsing process, according to experience, this process is the main process of regeneration, so many people call it exchange. The time required for the entire process is the same as the time for salt absorption, which is about 30 minutes.

Fast Rinsing

In order to thoroughly rinse off the remaining salt, the resin should be rinsed with raw water at a flow rate close to the actual working flow rate. The effluent from this process should be standard soft water, and the fast rinsing process takes about 5-15 minutes.

Fast Rinsing

As for the water softening filter equipment, it is widely used in steam boilers, hot water boilers, exchangers, evaporative condensers, central air conditioning, direct-fired engines, etc. The softening process of the makeup water in the system can be used. It can play a good role in the treatment of domestic water for hotels, restaurants, office buildings, and apartments, as well as softening water treatment in industries such as food, beverages, brewing, laundry, printing and dyeing, chemical, and pharmaceuticals.

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