Disinfect pool water with Chlorine

Operators of public swimming pools may choose from a number of different disinfection methods to treat pool water. According to German DIN 19643 standard, all chemicals are allowed to be disinfected. As follows:

Chlorine gas
Calcium hypochlorite according to E DIN EN 900 standard in powder or tablet form
Sodium hypochlorite according to E DIN EN 901 standard in the form of a concentration solution of 150 g / l
Sodium hypochlorite solution is produced locally by electrolysis
For a family-size pool, there are also many alternatives:

Bromine
Hydrogen peroxide
Iodine
silver
Trichlorisocyanuric acid
To disinfect pool water, Chlorine Gas is most commonly used globally. Especially suitable for treating large volumes of water, an economical solution. However, due to the risk of toxic leaks, chlorine gas is significantly restricted in Germany, especially in Switzerland.

Calcium hypochlorite in powder or tablet form is dissolved in water. In most cases, 1% of the disinfectant solution is formed. Because of the dispersion problem of more than 7% of the solid powder which is insoluble in water, the water is slightly cloudy.

Sodium hypochlorite is often used for small swimming pools, chemicals are often packaged in containers and the corresponding chemical cost is not so important. Chlorine electrolysis is also a common disinfection solution for swimming pool water with Sodium Hypochlorite.

For chlorine electrolysis, chlorine gas, hydrogen, and NaoH are generated from brine and electric current.

There is a difference between electrolytic without a diaphragm and electrolytic with screen. Electrolysis has no screen, the following electrolytes react to create sodium hypochloite solution with the remaining residual salt water. This method of electrolysis is often used for saltwater swimming pools, but for conventional pools it is a very volatile agent. The electrolyte has a screen that works with the two electrodes separated, so there's no residual salt water going into the pool water. The chlorine produced will either be added directly to the water in the form of hypochloric acid or it may be temporarily stored in the form of sodium hypochlorite with caustic sode created.

Automatic control

Chlorine-based disinfection method in most cases is adjusted chlorine concentration in water from 0.4 to 0.6 mg / l. Specifically, according to German DIN 19643 standard depending on the type of pool and water treatment, chlorine concentration requirements must be controlled as follows.

Swimming pool in general: 0.3 - 0.6 mg / l
Swimming pools generally have Ozone treatment to handle: 0.2 - 0.5 mg / l
Warm whirlpool (with or without Ozone operation): 0.7 - 1.0 mg / l - in environments where there are many microorganisms allowed to use up to 1.2 mg / l
Chorine concentration must be guaranteed accurately by amperometric measurement method. During bath time, a large number of fluctuating values ​​affect chlorine concentration, pH value and Redox value. Therefore, the set value can only be monitored continuously by automatic measurement and integrated control process.

In order to achieve acceptable levels, it is essential that the pool water be delivered to the probe in the quickest possible time. If not, the measurement process will not accurately reflect the water quality of the lake. The German standard DIN 19643 requires the water to be taken to be measured at a distance of 20 cm below the lake level and to be taken to the measuring electrode as quickly as possible. This requirement also applies to the process of measuring pH, Redox and temperature for water in lakes.

An accurate measurement result is only guaranteed when the chlorine tip is calibrated after a period of time of use. The DPD method is used for this process. The DPD method allows the assignment of a measured value to the controller. The process of measurement and control according to the DPD method is directly evaluated, whether the two measured values ​​are equivalent to each other. If the measured value by the PDP method is different from the continuous measurement value from the probe, the chlorine probe must be calibrated.

Thanks to the integrated P or PID control algorithm, the control process is calculated based on the difference between the set value and the measured value. Therefore, chlorine gas control valves or metering pumps or excess components will be controlled. Then, a closed automatic control process will be created, control parameters will be included. To adjust the control parameters, Prominent experts will be available to assist you.

Going back to the most important thing in the recommended pool water quality measurement range is to reduce pool water consumption as much as possible. Thanks to Prominent probes, the measured values ​​are always accurate with the measurement system using the open water extraction line.