ELECTRAGE Electrage 2013-14 | Page 35

THE INDUSTRIAL TOUR-EDUCATIONAL AND PRODUCTIVE On 28th February ’14, we, the students of B. Tech EEE (II/IV), NITW visited Visakhapatnam Steel Plant as part of our industrial tour along with two of our faculty members, namely Sri B.L. Narasimha Raju and P. Srinivasan. An employee of the Wire Rod Mill section of the plant was assigned to us as our guide and he accompanied us throughout our visit to the plant. We were first taken to the Coke Ovens where we witnessed a moving car opening and closing the door of a cell as part of the maintenance process. Coal is converted into coke by heating the prepared coal blend in the coke ovens at a temperature ranging between 1000 C and 1050 C. The volatile matter of coal liberated during this carbonization is collected in the gas collecting mains. The gas is first cooled and then drawn to the Coal Chemical Plant by exhauster. The residual coke is pushed out of the oven by pusher car through a guide into coke bucket. The red-hot coke is taken to Coke Dry Cooling Plant (CDCP) for cooling. We were taken around the plant by bus where we saw the pulverisation of coal in the Coal Handling Plant, Iron Handling Plant and the Coal Chemical Plant. The Coal Chemical Plant recovers Ammonia, Tar and Benzol from CO gas. The primary by-products from crude CO gas are Ammonium Sulphate, crude Tar, crude Benzol and cleaned coke oven gas. The cooled coke from CDCP is separated into three fractions namely BF coke, coke breeze and nut coke. We were then taken to the Blast Furnace-II out of the three blast furnaces in the entire steel plant where we saw liquid steel flowing like water. Iron is made in the blast furnaces by smelting iron bearing materials with the help of coke and air. The solid charge materials like sinter, sized iron ore, coke, etc are charged in the vertical shaft of the furnace at top and hot air blast is blown from the bottom. Oxygen from the hot air combines with the carbon of the coke and generates heat and CO. Eventually, the charge melts and hot metal and slag are produced and tapped out. 34