A new wet coke quenching process has been invented by an Ex-General Manager of Bhilai Steel Plant, Ravi Rattan Kerketta. The invention is now in the final stage of grant of patent. The invention is revolutionary because for the first time the heat energy of steam during the wet coke quenching is gainfully utilised. In traditional wet quenching, it is worldwide practice to let the steam escape to open atmosphere.

The invention addresses major problems of traditional wet coke quenching like, carbon emission (air pollution) during coke pushing from coke ovens, huge water consumption in quenching towers, generation of large phenolic water waste, particulate emission from drying coke in open wharfs. In addition high moisture content in coke increases the coke rate in Blast Furnaces (parameter for the consumption of BF coke measured in kilograms per ton of hot metal produced) as well affects balances within Blast Furnaces.

Mostly due to this reason, impurities like sulphur, phosphorus, ash, etc., increases, adversely affecting the productivity of blast furnaces. Increase in ash leads to expensive slag treatment. As per thumb rule 1% reduction in the ash content of the BF coke results into decrease in coke rate by 1 % to 1.5 %. Besides, higher phosphorus and sulphur in hot metal posses further problems in steel making.

Kerketta told that, he has conceptualised and designed six main machines and equipment for the new wet quenching technique. In the new technique, the hot coke is pushed through a specially designed pushing system into a coke transfer car in a completely closed environment to prevent any type of emission.

The transfer car carries hot coke to cooling station, in a closed compartment so that no fumes and particles escape to the atmosphere. The hot coke is then transferred to an uniquely designed coke disperse car, which spreads the hot coke on a tilting cooling bed. The hot coke is cooled by a non contact rapid evaporation system (which consumes very little quantity of water) and the hot steam is filtered and through negative pressure carried to a complex of multi cyclones and heat exchangers. Thus the heat energy of steam is gainfully utilised for hot air blast purpose which is subsequently used for augmentation of coke oven gas and also for drying of moist coke before supplying to blast furnaces. Kerketta explained that the new technique which is environment friendly could be easily installed as a brown field project since some of the equipments are similar to equipments which are in use in some form or other in iron and steel making companies.

Further, one of the main problem in traditional wet quenching is that of high moisture content in quenched coke, which could be completely eliminated and coke rate in blast furnaces be lowered. This will help in controlling the input cost of iron production and increase in profitability. Besides, the increase in availability of coke oven gas could reduce consumption of boiler coal in captive power plants, and also maintain gas balance in circuit when coke pushing is low. He further informed that after Kyoto Protocol, for United Nations Framework Convention on Climate Change, there is commitment by countries and economies to reduce green house gases emissions. India now stands committed to reduce Emissions Intensity of its GDP by 45 percent by 2030, and to achieve net-zero by 2070. It can be seen that, worldwide the iron and steel industry is one of the most energy intensive and polluting sector and it is high time to take stringent measures to achieve above targets. The new wet quenching technology will definitely help industries. R R Kerketta, is born and brought up in Bhilai, with schooling in English Medium Middle school sector-IX, Sr. Secondary School Sector-X, and Engineering from VRCE, Nagpur, now Visvesvaraya National Institute Of Technology (VNIT). He joined Bhilai Steel Plant as MTA in year 1989, and served in various departments like Purchase, Stores, Vigilance, IED, Towns Services, etc,. He has been granted two design patents, by Government of India viz. Paddy Storage Container and Rural Grain Godown. He took voluntary retirement in year 2020. He can be contacted at email id [email protected].