Coke Oven Gas, its Characteristics and Safety Requirements...

Coke Oven Gas, its Characteristics and Safety Requirements Coke oven gas (CO gas)  is a byproduct gas produced during the production of metallurgical coke in a byproduct coke oven battery, where metallurgical coal is carbonized by heating it in absence of air. During carbonization the volatile matter in the coal is vaporized and driven off. This volatile matter leaves the coke oven chambers as hot, raw coke oven gas. After leaving the coke oven chambers, the raw coke oven gas is cooled which results in a liquid condensate stream and a gas stream. These two streams are processed  in the byproduct plant to recover byproduct coal chemicals and to condition the raw coke oven gas so that it can be used as a fuel gas. The main emphasis of a modern  byproduct plant is to treat the raw coke oven gas sufficiently so that it can be used as a clean, environmentally friendly fuel. Raw coke oven gas after treatment in the byproduct plant is called clean coke oven gas or simply coke oven gas. The evolved coke oven gas leaves the coke oven chambers at high temperatures approaching 1100 deg C. This hot gas is immediately quenched by direct contact with a spray of aqueous liquor (flushing liquor). The resulting cooled gas is water saturated and has a temperature of around 80 deg C. This gas is collected in the coke oven battery gas collecting main. From the gas collecting main the raw coke oven gas flows into the suction main. The amount of flushing liquor sprayed into the hot gas leaving the oven chambers is far more than is required for cooling, and the remaining unevaporated flushing liquor provides a liquid stream in the gas collecting main that serves to flush away...

Understanding Coke Making in Byproduct Coke Oven Battery Mar09

Understanding Coke Making in Byproduct Coke Oven Battery...

Understanding Coke Making in Byproduct Coke Oven Battery  Coke is one of the basic materials used in blast furnaces for the conversion of iron ore into hot metal (liquid iron), most of which is subsequently processed into steel. The major portion of coke produced is used for the production of hot metal. Coke is also used by a number of other industries, namely iron foundries, nonferrous smelters, and chemical plants. It is also used in steel making as a carburizing material. Coke and coke by-products, including coke oven gas, are produced by the pyrolysis (heating in the absence of air) of suitable grades of coal. The process also includes the processing of coke oven gas to remove tar,  ammonia (usually recovered as ammonium sulphate), phenol, naphthalene, light oil, and sulphl, and sulfs under links n of coal)  period.e doorg nitrogen gas is used for the production of steam and then power.ur before the gas is used as fuel for heating the ovens. The coke making industry consists of two sectors, integrated plants and merchant plants. Integrated plants are owned by or affiliated with iron-and steel producing plants who produce blast furnace coke primarily for consumption in their own blast furnaces. Independent merchant plants produce furnace and/or foundry coke for sale in the open market. These plants sell most of their products to other plants engaged in blast furnace, foundry, and nonferrous smelting operations. A good quality coke is generally made from carbonization of good quality coking coal. Coking coals are defined as those coals that on carbonization pass through softening, swelling, and re-solidification to coke. One important consideration in selecting a coal blend is that it should not exert a high coke oven wall pressure and should contract sufficiently to allow the coke to...

Coke Oven Refractory Repairs Feb10

Coke Oven Refractory Repairs...

Coke Oven Refractory Repairs Coke oven battery is a refractory structure, contained within a steel and/or concrete exoskeleton. This exoskeleton is held together in the lateral direction by a series of tie rods between steel buckstays. The buckstays are vertical steel beams located on the ends of the heating walls between the ovens. In a longitudinal direction, the tie rods extend between the pinion walls on either end of the battery. The heating walls have traditionally been constructed of silica refractories. Silica is the refractory of choice primarily because, at normal coke oven battery operating temperatures, silica refractories are subject to minimal creep. Also, since nearly all of the expansion of silica bricks take place at temperatures which are below 650 deg C, hence the moderate temperature fluctuations of the walls have no effect on the volume stability of the refractory comprising the wall during normal operation of a battery. Coke oven batteries will have an operating life of twenty to forty years, depending upon operating conditions and battery maintenance. There are several examples of coke oven batteries working for 40 – 50 years due to correct operation and timely repair. There are also cases where the failures of coke oven refractories has happened in less than 10 years of its operations.  Usually a battery requires specific repairs to the refractories, steelwork or machinery. These repairs, if properly performed, extend the life of the battery. In order to prolong the service life of coke oven battery, it is essential to avoid damage to the oven wall. In particular, it is especially important to avoid brick breakage, since this causes an opening in the brick wall and the oven must be stopped, and the oven brickwork may be further damaged during the process of idling. The...

Coke making in Byproduct Coke Oven Batteries Jun01

Coke making in Byproduct Coke Oven Batteries...

Coke making in Byproduct Coke Oven Batteries  Coke causes up to 50 % of the costs during the hot metal production. The cost effective production of high quality coke is thus of prime importance for the competitive ability of the iron production. Metallurgical coke is used in iron and steel industry processes (primarily in blast furnaces) to reduce iron ore to iron. Over 90 percent of the total coke production is dedicated to blast furnace operations. Foundry coke comprises most of the balance and is used by foundries in furnaces for melting metal and in the preparation of moulds. Foundry coke production uses a different blend of coking coals, longer coking times, and lower coking temperatures relative to those used for metallurgical coke. Most coke is produced in the world using the byproduct coke oven batteries and most of the coke plants are integrated with iron and steel production facilities. The manufacture of coke by heating coal in absence of air has its origins at the start of industrial revolution when Abraham Darby used it in the smelting of iron ores in 1709 in England. The method of coke production was initially the same as for the production of charcoal, stockpiling coal in round heaps, igniting the piles, and then covering sides with clay. This laid the foundation for beehive coke making. Gradual advances led to the development of beehive, reverberatory and byproducts ovens, culminating into regenerative coke ovens with recovery of the byproducts around a century ago. Coal is converted to coke in large coke oven batteries by the destructive distillation of coal. The coking process consists of heating coal in the absence of air to drive off the volatile compounds. The resulting material is a carbon mass called coke which is a...