Analysis on the Reasons of Soft Water Hardness Exceeding the Standard in Boiler Softening Water Equipment

The test at the sampling port of the soft water equipment is qualified, but the water hardness in the soft water tank exceeds the standard. The reasons for this phenomenon are as follows:

  • The regeneration cycle is set too large, or the measurement is inaccurate due to the failure of the flow meter, so that the resin cannot be regenerated in time when it should be regenerated, resulting in the injection of excessive water into the soft water tank.
  • The washing time is too short, so that the waste salt water that should be washed away in the washing is partially brought into the soft water tank.
  • Too little water supply to the salt tank, too little salt absorption, and insufficient positive washing caused by unstable water pressure in the water supply, any of which can cause the water hardness to exceed the standard after the regeneration, affecting the water quality of the soft water tank.
  • When there is very little salt in the salt box, it cannot be added in time, resulting in a poor regeneration effect.
  • Improper operation, close the water supply valve during a regeneration process.

Any of the above errors can cause a large amount of excess water to fill the soft water tank in a short time. It takes a long time to dilute the excess water with qualified soft water to make the water in the soft water tank reach the standard again.

The hardness of the newly installed water softening equipment exceeds the standard for the first test and the hardness of the water softening equipment in use exceeds the standard.

Reasons why the hardness of the newly installed water softening equipment exceeds the standard in the initial test:

  • The O-ring at the junction of the central pipe and the control valve does not form a seal. At this time, it should be checked:
    • Whether the length of the central tube is sufficient and whether the outer diameter meets the requirements
    • Did you forget to install the O-ring seal?
    • Whether the O-ring is damaged
  • Broken and cracked on the central tube.
  • The ratio of the TDS value of the feed water to the height of the resin layer is too large.
  • The ratio of feed water TDS value to resin exchange capacity is too large.
  • The inlet and outlet connections are reversed.

Reasons why the hardness of soft water in the water softening equipment exceeds the standard:

  • The ratio of feed water TDS value to resin layer height or resin exchange capacity is too large. Compared with the initial water test of the new resin, the water softening equipment has stricter requirements on the TDS value of the water supply. When the height of the resin layer is 1.5 meters, the total hardness is 13mmol/L, and the TDS value of the water supply is ≧900mg/L, ensure that the soft water hardness is ≤0.03 mmol/L will be more difficult.
  • Resin poisoning, decrease in resin exchange capacity due to aging. The soft water hardness exceeding the standard caused by this reason is a gradual process, not a sudden and obvious exceedance.
  • The amount of salt in the salt tank is too low. When the amount of water in the salt tank is normal and the height of the salt is less than 1/3 of the height of the water, the brine sucked up in the middle and late stages of the salt absorption step is likely to be unsaturated, so that the brine concentration after dilution by the ejector is lower than the regeneration requirement , which affects the regeneration effect.
  • The total amount of water in the salt tank is too small. Our experience is that for every 100L of resin in the resin tank, the required amount of water in the salt tank is about 35-40L. Too much water below this standard will cause insufficient regeneration.
  • suction saline is too slow, in normal time, can not absorb enough saline, the reasons are as follows:
    • The water supply pressure is too low
    • Sediment and other debris in the upper and lower distribution water are seriously blocked
    • Poor drainage of waste water caused by deformation and bending of waste water hoses
    • Too many impurities in the resin layer
    • There is a leak point on the salt suction pipe, which makes the air sucked in
    • Foreign matter in the jet
    • The air check valve fails, closes in advance or is blocked
    • The selection of the ejector is too small

There is a large amount of gas in the resin tank, which may come from the gas in the feed water, or the air check valve is not closed tightly during the slow washing process.

  • No large grain non-iodized salt is used.
  • Internal leakage of the control valve: When the internal leakage of the general control valve is hard, the soft water outlet and the waste water outlet often come out at the same time, but for the 64D or 74A series, internal leakage may be formed through the small holes on the ceramic moving piece. The internal leakage is in the positive flushing position, and qualified soft water can be detected at the waste water outlet, but when it is transferred to the running position, the hardness of the soft water exceeds the standard. Since the hardness of water is mainly formed and represented by calcium and magnesium, cation exchange resin (water softener) is generally used to replace Ca2+ and Mg2+ (the main components of scale formation) in the water. With the increase of Ca2+ and Mg2+ in the resin, The resin removal efficiency of Ca2+, Mg2+ gradually decreased. After the resin absorbs a certain amount of calcium and magnesium ions, it must be regenerated. The regeneration process is to rinse the resin layer with salt water in the salt tank to replace the hardness ions on the resin. The softening swap function has been restored. Since the hardness of water is mainly formed by calcium and magnesium and indicates that the hardness of water is mainly formed by calcium and magnesium and indicates that the principle of sodium ion exchange softening treatment is to pass the raw water through the sodium cation exchange resin, the hardness components Ca2+, Mg2+ in the water and The Na+ in the resin is exchanged, thereby adsorbing Ca2+ and Mg2+ in the water and softening the water.

Xi’an CHIWATEC Water Treatment Technology is a high-tech enterprise specialized in various water processing devices. Aside from these individual products, which cover a number of types and series, we can also help with related comprehensive engineering projects. Thanks to our hard work and dedication upon our founding, we are now one of the fastest-developing water treatment equipment manufacturers in Western China.

Further reading:

15TPH softening system

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