Introduction of Reagent Acidity Adjustment Installations of Return Water of Heat and Energy Equipment of Metallurgical Enterprise

Abstract

The methods of regulating the indicator "pH water" of heat power equipment of metallurgical enterprise are analyzed. It is noted that the introduction of a reagent unit for regulating the indicator "pH of water" is the most optimal method. It was found that the use of the reagent has significant advantages compared with the repair of heat and equipment, which is affected by changes in water properties. This method is reliable, predictable, and analytical. The analysis of statistical information, the dynamics of changes in the required percentage of chemical reagents to obtain indicators with the value of "norm" at PJSC "Arcelor Mittal Kryvyi Rih" was carried out. Attention is focused on reaching regulatory indicators by the number of suspended substances, for which the treatment of circulating water with flocculants is used. To reduce the rate of corrosion and the formation on the surface of heat-and-power equipment of the gas cleaning film, which prevents corrosion, the treatment of circulating water with anti-corrosion inhibitors is used. Methods for regulating the indicator "ph water" have been systemized for the heat and power equipment. It is established that the transition of metallurgical enterprises to the method of regulating the indicator "ph water" for heat and power equipment with the help of a reagent is recommended firstly: after analyzing the need for automation of the process ( chemical reagent is often introduced into the water cycle), and secondly: the readiness of the enterprise for large investments ( reagents and chemical reagents for it are expensive), and thirdly: having a regional service representative, because there are not many service specialists). There have been proposed technological solutions affecting water quality indicators, namely efficiency of blast furnace dust collector (BF)-9, efficiency of gas cleaning elements of GO-5, raw materials and technological load of BF-9. Experimental laboratory tests of complex water treatment of GO-5 DP-9 cooling system were conducted. As a result, the estimated amount of 45 % NaOH solution to bring the pH of return water to the normative requirements of not less than 7,0, which is 134 tons of NaOH per month, was established. It is noted that the proposed method will lead to the introduction of NaOH, flocculants and corrosion inhibitors, which will reduce the presence of suspended solids from 150…200 mg/dm to 20 mg/dm, increase water pH to 7 units or higher. This will lead to a significant reduction in abrasion and chemical wear of the Go-5 DP-9 equipment and the water supply department pump station, which, in turn, will increase the service life of the heat and power supply and reduces the repair cost of this equipment.