Factors affecting Coke rate in a Blast Furnace Jun29

Factors affecting Coke rate in a Blast Furnace...

Factors affecting Coke rate in a Blast Furnace  BF is a counter current reactor in which the reducing gas is produced by the gasification of the carbon of the BF coke with the oxygen of the hot blast injected via tuyeres in the lower part of the furnace. The reducing gas flows upwards reducing the iron bearing burden materials charged at the top of the furnace. Coke rate is the parameter for the consumption of BF coke which is measured in kilograms of BF coke consumed per ton of hot metal produced. Blast furnace (BF) coke is a key material for BF ironmaking, acting as a major energy source (fuel), a reductant, a carburization agent and a permeable structural support. There is no other satisfactory material available, which can replace, fully or partially, BF coke as a permeable support of blast furnace charge. BF coke is the most important raw material fed into the blast furnace in terms of its effect on blast furnace operation and hot metal quality. A high quality BF coke is able to support a smooth descent of the blast furnace burden with as little degradation as possible while providing the lowest amount of impurities, highest thermal energy, highest metal reduction, and optimum permeability for the flow of gaseous and molten products. Introduction of high quality BF coke to a blast furnace results in lower coke rate, higher productivity and lower hot metal cost. Role of coke in improving the BF performance is shown at Fig 1. Fig 1 Role of coke in improving BF performance A realistic assessment of the likely performance of coke in the blast furnace operating with or without injection technology includes those properties of coke that reflect its resistance to degradation under the chemical and...

Dry Cooling of Coke Apr25

Dry Cooling of Coke

Dry Cooling of Coke Dry cooling of coke is known as coke dry quenching (CDQ) and is an alternative to the traditional wet quenching.  During wet quenching of run of oven coke, sensible heat of the hot coke is dissipated into the atmosphere and is lost. In addition there are air borne emissions (0.5 ton of steam per ton of coke laden with phenol, cyanide, sulfide and dust) and a large quantity of water (around 0.6 Cu m per ton of coke) is needed for wet quenching. The contaminants in water are also discharged in the environment. In a Coke Dry Cooling Plant (CDCP) red hot coke is cooled by inert gases. The heat energy from the red hot coke is recovered in a waste heat boiler for use as steam, resulting in energy conservation as well as a reduction in coke particle emissions.  Around 80 % of sensible heat is recovered. The CDCP process flow is in Fig 1. Fig 1 Process flow in CDCP History After pilot and pilot/commercial trials the first full scale CDCP installation was commissioned in 1965 at the Cherepovets Iron and Steel Works in then USSR. By 1978 around 50 CDCP modules of 56 tons per hour were in operation in then USSR. Japan purchased license from USSR and three Japanese installations were commissioned in 1976 – 77. In India MECON purchased license for Giprokoks design CDCP from USSR and the first 12 chambers were installed at Visakhapatnam Steel Plant. The first CDCP plant was commissioned in September 1989. Presently 19 chambers of this design are in operation. Concept of Coke Dry Cooling Hot coke is brought from the battery to the CDCP in bottom opening bucket kept on the quenching car. This bucket is lifted at the...