According to GB 1576 "Water Quality Standard for Industrial Boilers", the hardness of steam boiler make-up water is ≤0.03mmol/L, and if it is greater than this value, it will exceed the standard. Excessive hardness can be divided into two categories:
1. The sampling port of the water softener passed the test, but the water hardness in the water softener tank exceeded the standard. The reasons for this phenomenon are as follows:
A, the regeneration cycle is set too large, or the metering caused by flowmeter failure is not allowed, so that the resin can not be regenerated in time when it should be regenerated, resulting in excessive water injection into the soft water tank.
B, the washing time is short, so that the waste brine that should have been washed away in the washing process is taken to the soft water tank.
C. The salt tank caused by unstable water supply pressure has too little water supply, too little salt absorption and too little flushing, any of which may cause the hardness of the effluent after this regeneration to exceed the standard and affect the water quality of the soft water tank.
D when the amount of salt in the salt tank is small, it cannot be added in time, resulting in poor regeneration effect.
E, improper operation, close the water supply valve in the process of regeneration.
Any of the above mistakes may lead to a large amount of over-standard water being injected into the soft water tank in a short time, and it takes qualified soft water to dilute the over-standard water for a long time to make the water in the soft water tank reach the standard again.
2. After repeated testing at the sampling port of the water softener, all the samples were unqualified. This situation is divided into two parts: the hardness of the newly installed water softener tested for the first time and the hardness of the water softener equipment being used.
The reason why the hardness of the first test water exceeds the standard
A. The O-ring seal at the joint between the central pipe and the control valve does not form a seal, so check:
L whether the length of the central pipe is sufficient and whether the outer diameter meets the requirements. L Did you forget to install the O-ring?
Is the O-ring seal damaged?
B. the central pipe is damaged and broken.
The ratio of TDS value of feed water to the height of resin layer is too large.
D the ratio of TDS value of influent to resin exchange capacity is too large.
E. the water inlet and outlet are upside down.
B. The reason why the hardness of the water softener in use exceeds the standard:
A the ratio of TDS value of feed water to resin layer height or resin exchange capacity is too large. Compared with the initial water test of new resin, the requirement of TDS value of water supply is more stringent when using soft water equipment. When the height of resin layer is 1.5m, the total hardness is 13mmol/L, and the TDS value of water supply is ≥ 900mg/L, it will be more difficult to ensure the hardness of soft water is ≤ 0.03mmol/L. ..
B resin poisoning, resin aging causes the exchange capacity to decrease. The hardness of soft water caused by this reason is a gradual process, not a sudden and obvious hardness exceeding the standard.
There is too little salt in the salt box. When the amount of water in the salt tank is normal and the height of salt is less than 1/3 of water, the salt water sucked in the middle and late stage of the salt absorption step is likely to be unsaturated, which makes the concentration of salt water diluted by the injector lower than the regeneration requirement and affects the regeneration effect.
The total amount of water in the salt tank is too small. Our experience is that for every 100L resin in the resin tank, the water in the salt tank is about 35-40L. Too much water below this standard will lead to insufficient regeneration.
E salt water absorption is too slow to inhale enough salt water at ordinary times. The reason for this is the following：
L feed water pressure is too low
L the sediment and other sundries in the upper and lower water distribution are seriously blocked.
L the waste water hose is deformed and bent, resulting in poor drainage.
There are too many impurities in the resin layer.
L there is a leak in the salt suction pipe, which causes air to be sucked in.
L there is a foreign body in the ejector.
L air check valve fails, closes prematurely or is blocked.
L injector selection is too small.
3. There is a lot of gas in the resin tank, which may come from the gas in the water, or the air check valve is not closed during the slow washing process.
G no large amount of non-iodized salt was used.
H Hard leakage inside the control valve: Generally, when hard leakage occurs inside the control valve, the soft water outlet and waste water outlet often come out at the same time. However, for the 64D or 74A series, internal leakage may be formed through small holes in the ceramic rotor. If this kind of internal leakage is in the positive flushing position, qualified soft water can be detected at the wastewater outlet, but the hardness of soft water exceeds the standard after it is transferred to the running position.