Cooling for steel mill’s oxygen process line during rising heat in the summer months

The steel sector is a key GDP contributor to the South Korean economy, driving other key manufacturing sectors such as shipbuilding, automobiles and semi-conductors - a real driving force behind the economy. With such high domestic market dependency, production schedules are tight, and demand is high.

One of South Korea’s leading Steel manufacturer faced an issue from July to September, the hottest months in the Korean Summer. With ambient temperatures rising up to 43⁰c, the performance of its oxygen processing unit was compromised due to the climbing temperature in cooling water.

A rise in temperature would mean a drop in efficiency of cooling. Oxygen is used as a process agent that kick-starts a series of intensively exothermic (heat-releasing) reactions, including the oxidation of such impurities as carbon, silicon, phosphorus, and manganese.

The cooling water into the oxygen production line has to be maintained and pumped in at the precise temperature of 13 ⁰c to achieve the stringent quality standards set by the plant. Any lapse will result in quality failures and a redundant product which may not pass the stringent quality control checks.

The steel mill’s maintenance team needed a temporary solution to enhance the cooling capacity and to supplement with additional cooling.

Aggreko was called upon to propose and deliver a temporary cooling system to supplement additional cooling for the oxygen unit. Our temperature control engineers conducted a scoping study with the steel mill’s maintenance team and thoroughly examined and diagnosed of any potential detrimental issues.

A bespoke engineered solution was proposed where one 800kw air-cool chiller was installed and integrated to the oxygen’s existing cooling unit. The water outlet of hirer’s cooling tower was cooled from 18 to 13 degrees Celsius before being pumped to the oxygen production facility.

With Aggreko’s best-in-class equipment maintenance and quality control standards in place, our equipment stood operated flawlessly for 90 days, 24/7 meaning a continuous operation of 2,160 hours, cooling a staggering 540K Tons of water in total.

The need for the steel and the demand that the customer faced from the sector meant that the delivery of raw materials out to the downstream clients is vital. The precision cooling ensured the continuous delivery of oxygen at an optimal temperature level.

The environmental impact of maintaining the oxygen unit in its desired low temperature also helped decreased and maintained sulphur dioxide and ammonia levels which the customer closely monitors as part of its environmental sustainability goals.

The cooling solution ensured that the customer’s contractual agreements were met and that no fines were incurred. Our bespoke cooling solution enabled the steel mill to continue to produce the essential steel sheets, plates and grilles etc. in a timely manner safeguarding its reputation and leading position in the ever-competitive steel marketplace.