Converting to coal: how the savings stack up against cost and aggravation

Compelling reasons abound to consider converting boilers to coal from oil or gas. Calculations have shown that the savings can be large (Energy Research Reports, September 1975). At current prices, converting a boiler that produces 200,000 pounds of steam per hour will cut fuel costs by $140 to $230 per hour. Power plants vary as do coals; the abundance of technical problems raised by these variations can be grouped in three classes: coal handling and ash removal, emission control, and boiler modifications. Only boiler modifications are discussed in this paper, but potential converts should be aware that the other classes can be as complex. Gas, oil, and coal impose unique requirements for boiler design, affecting such components as burners, the fuel-supply system, such accessories as soot blowers and fans, and boiler-control systems. Furnace size and spacing of convective tubes are especially important because they can make it impossible to convert from gas to coal. (MCW)