Furnace firing

Primary smelting can be carried out in a reverberatory, rotary, or electric furnace. The choice depends more on economic circumstances than on technical considerations (3). Thus, in the Far East, reverberatory furnaces fired with anthracite coal as the reductant were and still are widely used. 

Mercury from cinnabar ore 225 tons ore/day (95% recovery) (2) 18,0 ft. diam, 8 hearth furnaces Furnaces fired on hearths 3 to 7, inclusive retention time of 1,0 hr, furnaces are oil-fired with low-pressure atomizing air burners all air, both primary and secondary, introduced through the burners draft control by Monel cold-gas fans downstream from mercury condensers. 

Fired heaters differ from other indirect-fired processing equipment in that the process stream is heated by passage through a coil or tubebank enclosed in a furnace. Fired heaters are classified by function and by coil design. 

Hazard of Water, Hazard of Air, Safe Furnace Firing, etc., Nine booklets published by The American Oil Company, Chicago. 

Volumetric heat release rates The rates of volumetric heat release from shell boiler furnaces fired by oil and gas are typically 175,000 to 235,000 Btu/ft3/hr. (Heat releases from the various tube passes are significantly lower than from the furnace, thus reducing the overall heat-flux rating.)... 

In a test on a furnace fired with natural gas (composition 95 per cent methane, 5 per cent nitrogen) the following flue gas analysis was obtained carbon dioxide 9.1 per cent, carbon monoxide 0.2 per cent, oxygen 4.6 per cent, nitrogen 86.1 per cent, all percentages by volume. 

An aluminum scrap fire developed near a melting furnace. Fire departments responded and sprayed water on the flames. Suddenly the pot furnace exploded. It is presumed that water from the fire hoses entered the furnace which contained about 900 kg of molten aluminum... 

Who breaks his tables and his chairs To feed his furnace fires. . . ... 

If you try to operate a furnace, fired heater, or boiler with too little combustion air to starve the burners of oxygen to smother or bog down the firebox, then you will likely cause afterburn or secondary combustion in the stack, you will not be able to operate on automatic temperature control, and may even destroy the equipment altogether. 

Bunsen is remembered chiefly for his invention of die laboratory burner umned after him. He engaged in a wide range of industrial and chemical research, including blast-furnace firing, electrolytic cells, separation of metals by electric current, spectroscopic techniques (with Kirchhoff). and production of light metals by electrical decomposition of their molten chlorides. He also discovered two elements, rubidium and cesium. 

Direct-fired furnace. Fired heaters are designed to increase the process temperature of oil and gas streams. This increase of temperature in most every case does not change molecular structure. Thus, temperatures up to 500°F maximum with 400°F design are very common. Designs are usually cylindrical, with vertical radiant tube banks fired by oil/gas combination burners. 

However, a small-diameter tube gives more pressure drop for a given flowrate through each tube and a given tube length. Of course, a larger number of parallel tubes that are shorter can be used to keep pressure drop at a reasonable level, but this increases the shell diameter of the reactor, which increases the cost. Mechanical problems also limit the minimum tube diameter. Typical tube diameter in cooled tubular reactors is 0.03 m. Typical tube diameter in a furnace-fired heated tubular reactor is 0.15 m. 

In this flowsheet the presence of the furnace provides an additional control degree of freedom, and there are now two controllers. The first G( (X) controls 7 lmx by manipulating bypass flow Fby. The second Gc2(s) controls Tm by manipulating furnace firing QF. The second controller sees the furnace transfer function GF2(S) which we assume to be a furnace first-order lag and three small lags (see Fig. 7.4b) ... 

The Institution of Chemical Engineers markets Ha/ards Workshop 005, which is entitled Furnace Fires and Explosions. [1] One of the advertising leaflets for this workshop makes the following generalization Furnaces are comparatively simple items for a plant, and because they are unsophisticated they tend to be imperfecdy understood by operators and plant managers alike. Their tolerance to abuse is limited, and once abused their useful life can be drastically shortened. Worse still they may fail suddenly, since furnace tubes distort easily and then fracture. Such failure is often severe, with a consequential fire and/or explosion. ... 

Institution of Chemical Engineers, Furnace Fires and Explosions, Hazard Workshop Module 005, Rugby, U.K. (available as a training kit with 23 35mm slides, booklets, teaching guides, and related materials). 

Figure 7.7 shows a typical furnace/boiler configuration and its control system. Steam pressure in the 1000-psia header is maintained by furnace firing (the air controls are not shown). Steam pressure in the 300-psia header is controlled by either removing more steam from the turbine if the pressure is too low or dropping steam into the 150-psia header if the pressure is too high. Similar strategies are used for the... 

The Institution of Chemical Engineers markets "Hazards Workshop 005, which is entitled Furnace Fires and Explosions. [1] One of the advertising leaflets for this workshop makes the following generalization ... 

The 1984 AMOCO Oil hardcover book is an accumulation of nine individual, previously published booklets. The booklets are each chapters in the 1984 edition with titles including The Hazards of Water, The Hazards of Air, Safe Furnace Firing, Safe Ups and Downs for Refinery Units, The Hazards of Steam, and other fundamentals needed by operators, supervisors, and engineers. 

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