The ring cooling water system tends to use an alkaline organic phosphorus-based formula as a water quality stabilizer, which provides a nutrient source for the reproduction of bacteria and algae, and bacteria, fungi, algae, protozoa and other microorganisms use the nutrients in the water to multiply. Chlorine dioxide does not react with ammonia to form chloramine with low bactericidal efficacy, and it has low reactivity with organic substances, is not easily consumed by organic substances in water, and does not form chlorinated organic substances. In addition, chlorine dioxide has a fast sterilization speed, a long decay period in water, and a long-lasting effect. Moreover, chlorine dioxide does not precipitate with water quality stabilizers such as organic phosphorus, and has no effect on the corrosion and scale inhibition of water quality stabilizers. Corrosion experiments on metal equipment by chlorine dioxide show that: 80 ～ 120ppm of chlorine dioxide is basically non-corrosive to stainless steel and copper, and 20 to 80 ppm of chlorine dioxide is basically non-corrosive to carbon steel, so the sterilization concentration of chlorine dioxide in circulating water Below 80 ppm, it will not cause equipment corrosion. It can be seen that chlorine dioxide is a circulating water bactericidal and algicide that deserves widespread promotion.

    Equipment selection

    Generally speaking, the dosage of chlorine dioxide in industrial circulating water treatment should be related to the purpose of cooling water treatment. If it is only used to control the proliferation of cooling tower microorganisms, the effective chlorine detection concentration in circulating water should not be less than 0.3mg / L. The effective chlorine dosage is generally 1-2 mg / L. The effective chlorine dosage shall refer to the original chlorine dosage, and the dosage time and interval shall refer to the original management method. Circulation volume per hour ≥ 2 times the retained water volume: [Circulation volume per hour] Take the larger to approach the equipment model

    other:

    [Retained water quantity × Effective chlorine dosing time ÷ Dosing time] Approach to the model of Datong

    The effective chlorine dosage is 3 to 7 mg / L, and each dosage is 6 to 8 hours.

    The effective chlorine dosage and interval dosage during operation should be adjusted according to the residual chlorine value in the water.

    3. Process flow and description

    Process description: The circulating cooling water system is generally composed of a heat exchanger, a cooling tower, a filter tank and a storage tank. Chlorine dioxide is generally directly added to the storage tank and lifted by a pump.

    Equipment

(1) Biocides in circulating water are generally dosed periodically. Dosing points are generally selected in cold pools, and dosing periods should be determined based on water quality.

(2) In general, the dosage of compound chlorine dioxide in industrial circulating water treatment should be related to the quality of cooling water, and the effective dosage of chlorine per time is 3-7 mg / L.

(3) For DC cooling water system, continuous dosing can be adopted, and the dosing amount is automatically adjusted according to the change of the circulating water amount, so that the effective chlorine in the circulating water is maintained at a certain concentration. Selection refers to drinking water.