Low-phosphorous composite corrosion and scale inhibitor for circulating cooling water of closed cooling tower and preparation method of low-phosphorous composite corrosion and scale inhibitor

Abstract

The invention belongs to the field of water treatment, and particularly relates to a low-phosphorous composite corrosion and scale inhibitor for circulating cooling water of a closed cooling tower and a preparation method of the low-phosphorous composite corrosion and scale inhibitor. The low-phosphorous composite corrosion and scale inhibitor comprises, by weight, 5-15% of N-sulfonic amino-dimethylenephosphonic acid, 5-20% of 2-hydroxyphosphonoacetic acid, 30-50% of polyglutamic acid, 5-10% of heptahydrate and the balance deionized water. The formula components of the low-phosphorous composite corrosion and scale inhibitor have obvious synergistic interaction, and the low-phosphorous composite corrosion and scale inhibitor is particularly applicable to a circulating cooling water system of the closed cooling tower; the problems of corrosion and scale formation of the system after long-time operation of the circulating cooling water can be solved effectively, indexes such as corrosion rate of carbon steel, copper, stainless steel and the like can meet national standards, the corrosion rate of the carbon steel is lower than 0.075mm / a, and the corrosion rates of the copper and the stainless steel are lower than 0.005mm / a; the content of phosphorus in the formula is low, and emission standards can be met without treatment; the production process is simple, and product stability is high.

Description

technical field

[0001] The invention belongs to the field of water treatment, and in particular relates to a low-phosphorus composite corrosion and scale inhibitor for circulating cooling water of a closed cooling tower and a preparation method thereof. Background technique

[0002] The circulating water of the closed cooling tower has almost no contact with the outside world and is not easy to be polluted. Due to less contact with the outside world, the loss of water is very small, the amount of make-up water is small, and the circulation period of the circulating water is long, but there are also problems of corrosion and scaling. If softened water is used as circulating water, although the scaling problem is alleviated, the corrosion problem is still serious. SUMMARY OF THE INVENTION

[0003] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a low-phosphorus composite corrosion and scale inhibitor for the circulating coolin...

Examples

Embodiment 1

[0018] A low-phosphorus composite corrosion and scale inhibitor for circulating cooling water in a closed cooling tower is composed of the following components by weight: N-sulfoaminodimethylidene phosphonic acid 10%, 2-hydroxyphosphonoacetic acid 15% %, polyglutamic acid 40%, zinc sulfate heptahydrate 5%, deionized water 30%, total phosphorus content is 6.75%. The preparation method is as follows: sequentially adding N-sulfonic acid amino dimethylidene phosphonic acid, 2-hydroxyphosphonoacetic acid, polyglutamic acid and deionized water into the reaction equipment at normal temperature, and then adding heptahydrate sulfuric acid during the stirring process Zinc, stir well and let stand.

Embodiment 2

[0020] A low-phosphorus composite corrosion and scale inhibitor for circulating cooling water in a closed cooling tower is composed of the following components by weight: N-sulfoaminodimethylidene phosphonic acid 5%, 2-hydroxyphosphonoacetic acid 20% %, polyglutamic acid 30%, zinc sulfate heptahydrate 10%, deionized water 35%, total phosphorus content is 6.5%. The preparation method is as follows: sequentially adding N-sulfonic acid amino dimethylidene phosphonic acid, 2-hydroxyphosphonoacetic acid, polyglutamic acid and deionized water into the reaction equipment at normal temperature, and then adding heptahydrate sulfuric acid during the stirring process Zinc, stir well and let stand.

Embodiment 3

[0022] A low-phosphorus composite corrosion and scale inhibitor for circulating cooling water in a closed cooling tower is composed of the following components by weight: N-sulfoaminodimethylidene phosphonic acid 15%, 2-hydroxyphosphonoacetic acid 8% %, polyglutamic acid 50%, zinc sulfate heptahydrate 7%, deionized water 20%, total phosphorus content is 6.5%. The preparation method is as follows: sequentially adding N-sulfonic acid amino dimethylidene phosphonic acid, 2-hydroxyphosphonoacetic acid, polyglutamic acid and deionized water into the reaction equipment at normal temperature, and then adding heptahydrate sulfuric acid during the stirring process Zinc, stir well and let stand.

technical field

[0001] The invention belongs to the field of water treatment, and in particular relates to a low-phosphorus composite corrosion and scale inhibitor for circulating cooling water of a closed cooling tower and a preparation method thereof. Background technique

[0002] The circulating water of the closed cooling tower has almost no contact with the outside world and is not easy to be polluted. Due to less contact with the outside world, the loss of water is very small, the amount of make-up water is small, and the circulation period of the circulating water is long, but there are also problems of corrosion and scaling. If softened water is used as circulating water, although the scaling problem is alleviated, the corrosion problem is still serious. SUMMARY OF THE INVENTION

[0003] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a low-phosphorus composite corrosion and scale inhibitor for the circulating coolin...

Examples

Embodiment 1

[0018] A low-phosphorus composite corrosion and scale inhibitor for circulating cooling water in a closed cooling tower is composed of the following components by weight: N-sulfoaminodimethylidene phosphonic acid 10%, 2-hydroxyphosphonoacetic acid 15% %, polyglutamic acid 40%, zinc sulfate heptahydrate 5%, deionized water 30%, total phosphorus content is 6.75%. The preparation method is as follows: sequentially adding N-sulfonic acid amino dimethylidene phosphonic acid, 2-hydroxyphosphonoacetic acid, polyglutamic acid and deionized water into the reaction equipment at normal temperature, and then adding heptahydrate sulfuric acid during the stirring process Zinc, stir well and let stand.

Embodiment 2

[0020] A low-phosphorus composite corrosion and scale inhibitor for circulating cooling water in a closed cooling tower is composed of the following components by weight: N-sulfoaminodimethylidene phosphonic acid 5%, 2-hydroxyphosphonoacetic acid 20% %, polyglutamic acid 30%, zinc sulfate heptahydrate 10%, deionized water 35%, total phosphorus content is 6.5%. The preparation method is as follows: sequentially adding N-sulfonic acid amino dimethylidene phosphonic acid, 2-hydroxyphosphonoacetic acid, polyglutamic acid and deionized water into the reaction equipment at normal temperature, and then adding heptahydrate sulfuric acid during the stirring process Zinc, stir well and let stand.

Embodiment 3

[0022] A low-phosphorus composite corrosion and scale inhibitor for circulating cooling water in a closed cooling tower is composed of the following components by weight: N-sulfoaminodimethylidene phosphonic acid 15%, 2-hydroxyphosphonoacetic acid 8% %, polyglutamic acid 50%, zinc sulfate heptahydrate 7%, deionized water 20%, total phosphorus content is 6.5%. The preparation method is as follows: sequentially adding N-sulfonic acid amino dimethylidene phosphonic acid, 2-hydroxyphosphonoacetic acid, polyglutamic acid and deionized water into the reaction equipment at normal temperature, and then adding heptahydrate sulfuric acid during the stirring process Zinc, stir well and let stand.