Corrosion Control in Iron and Steel Manufacturing Critical Rooms
Iron and Steel plants traditionally had a low level of automation. However, this is no longer true today. Major Iron and Steel owners are making large investments in process computers and modern generation distributed control systems to boost product quality and plant productivity. This modernization of steel plants is occurring in many countries in the world today. This technology urbanization has made Gas Phase Filtration a necessity for corrosion control in iron and steel manufacturing.
Process of Air Contamination in an Iron and Steel Mill
Iron and Steel mills can basically be broken down into two process areas :
- Metallurgical area
- Mills’ section
Corrosive and Toxic Gas Filtration – Necessity in Coking Plants
In the metallurgical area, coal, coke, iron ore, manganese and other basic core materials from which steel is made, are brought into the plant. If the mill is integrated, these components are then pre-processed in various plant sections (sintering plant, briquette plant, coking plant). The main source of corrosive and toxic gases is the coking plant in which coal is converted to coking coal.
During the coking process, the coal is subjected to high temperatures in an oxygen-depleted atmosphere, and many volatiles are driven off the coal. As coal also contains a great deal of nitrogen-based compounds, which are released to the atmosphere during the coking process, high concentrations of oxides of nitrogen (NOx) and ammonia are found. NOx levels inside the coking plant can peak at around 5 PPM and ammonia levels are also very high, with levels between 20 to 50 PPM at peaks, which makes air and gas purification necessary criteria.
Usually, the first stage in an iron and steel plant is the blast furnaces. Due to high temperatures at furnaces sulphur dioxide is produced in high quantities from hydrogen sulphide, as well as carbon monoxide and ammonia.
Acidic Gases Control in Annealing Furnace and Galvanising Lines
In the mills’ section, the steel is converted from continuous cast slabs or rolled slabs to a variety of plates, rods or sheets in various dedicated mills. Within the mills’ section, the galvanising/tinning mill is often associated with high concentrations of sulphuric acid and hydrochloric acid fumes, which is a major source of air contamination. If the plant has galvanising/tinning lines, then there may also be a hydrochloric acid regeneration plant. These acid regeneration plants tend to have extremely high concentrations of chlorine gas, chlorine and hydrochloric acid. Also, in the mills section, use is often made of annealing furnaces. These annealing furnaces tend to have higher sulphur levels around them.
Electronic Corrosion at Control/Switchgear Rooms and Motor Control Center
Electronic process controls are found throughout iron and steel plants, managing various processes in the conversion of raw materials into finished products. Control rooms, switchgear rooms, and motor control centers are commonly located in metallurgical plant areas, exposing them to electronic corrosion due to the corrosive and toxic gases emitted in these environments. Therefore, corrosion control in iron and steel manufacturing becomes a necessary measure, especially in metallurgical areas.
Corrosion Control in Iron and Steel Manufacturings Control/MCC Rooms
In the case of rooms with very low movement of personnel coming in and out, only pressurisation with chemically cleaned air is sufficient. Provide from 3 to 6 air changes per hour to attain approximately 2.5 to 5 mm WC positive pressure inside the room.
Rooms with high pedestrian traffic, such as operator control rooms, require air purification by recirculation mode in addition to air pressurisation. This is crucial for corrosion control in iron and steel manufacturing, as contaminants absorbed on the clothes and body surfaces of plant personnel can desorb upon entry to a relatively cleaner area. Ensuring air quality through effective pressurisation and purification is essential to maintaining a safe and efficient working environment.
The Most Effective Way of Removing Airborne Molecular Contamination
Bry-Air Gas Phase Filtration Systems protect electronic equipment and devices from the threat of abrupt failures due to corrosive gases. It reduces downtime by removing corrosive gases through the process of adsorption and chemisorption. Specifically designed for corrosion control in iron and steel manufacturing, these systems maintain the ANSI/ISA-71.04-2013 standard, IEC standards, and various other environmental standards followed by electronics manufacturers.
Bry-Air: A Step Ahead, Always
Bry-Air is the only Gas Phase Filtration Company in India having its own R&D and Testing Lab for granular media and chemical filters. Backed by world-class technology and systems, the laboratory is capable of testing the performance of impregnated/non-impregnated loose granular media and impregnated/non-impregnated air cleaning devices such as chemical filters, under one roof. The tests are conducted as per ISO/ASHRAE Standard 145.1 and BSR/ASHRAE Standard 145.2/ISO Standard 11155-2 guidelines. The core objectives of the tests are to assess the performance and efficiency of loose granular sorptive media and chemical filters in any particular application, including corrosion control in iron and steel manufacturing.
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