COLD REPAIR OF COKE OVEN BATTERIES
Physical deterioration of coke oven batteries in comparable operation conditions is basically determined by the changes in size and condition of refractory brickwork of coking chamber.
Major defects of refractory brickwork and reinforcing elements at coke oven batteries of Giprokoks design (Kharkov, Ukraine) with the size of chambers h=7 m, b=0,41 m, L=16 m and chamber volume V=41.6 m³, becomes evident after 12-15 years of coke oven battery operation.
The main defects determining the necessity of major overhaul for such coke oven batteries are:
- big cracks with displacement of brick-shapes in 1-3 vertical flues;
- undercuts on the chambers’ walls in 1-2 courses from the oven’s sole level;
- bricks fracture under charging and gas take-off holes (up to through-holes);
- desintegration of flash plates;
- deflection of anchor columns for more than 40-45 mm;
- considerable leakages in the gun-flue zone and regenerators, causing burning of leaking gas.
At the same time unsatisfactory conditions of operation and loss of 30-50% of the battery’s planned production capacity compel to stop the battery for the major overhaul with replacement of the worn out brickwork, reinforcements, gas take off and other equipment.
LLC “OKOS” has experience of major overhauls of coke oven batteries of high productivity with the restoration of the battery’s planned production capacity. Description of such repair executed by our company at Coke Oven Battery №2 for Visakhapatnam Steel Plant (India) in the year of 2000 is presented hereunder.
Coke Oven Battery №2, PVR system, Giprokoks design, chambers’ volume 41,6 m ³, height - 7 meters, was stopped on the 02.05.2000 for the major overhaul due to complete deterioration of chambers’ brickwork, partial wear out of inclined flue zone, complete deterioration of anchorage, gas take off equipment, gas collecting mains, other equipment and battery metal structures.
During cooling of the battery, additional adjustable reinforcing of inclined flue zone and regenerators’ walls was applied for the first time to lessen the breaks of refractory brickwork thus reducing the scope of repair.
Repair of coke oven battery in the above-stated scope of replaced refractory brickwork, reinforcing, all gas take off equipment, gas collecting mains, gas-air valves, flash plates, frames, doors and its commissioning was carried out within 11 months. The executed repair restored planned production capacity of Coke Oven Battery № 2 in conformity with Building Codes and Regulations.