This paper covers briefly the progress that has been made in the generation of power in industrial plants. The author points out that industries and utilities are cooperating in the generation and interchange of electric energy in order to reduce waste in many manufacturing processes.
Higher steam pressures and temperatures are widely used, along with superposition of new turbines on old equipment. Only a few installations have pressures and temperatures which exceed 900 lb per sq in. and 850 F, respectively. A number of prominent industrial plants are described to indicate the application of all types of steam turbines to the three steam cycles most commonly employed. Steam-pressure-reducing and desuperheating equipment, as developed for topping units in central stations, is finding new applications in industry. Where large quantities of process steam are needed, many interesting arrangements of modern equipment can be used to reduce the cost of power generation.
The trend in design of boilers is toward larger units, higher steaming rates, and more complicated automatic controls to permit utilization of several different kinds of fuel in the same furnace. This presupposes the proper treatment of boiler feedwater, the importance of which is emphasized. Operating data from two outstanding installations are included. Among smaller plants there is a tendency toward the use of a self-contained boiler; also, there has been a revival of semi-outdoor constructions.
Progress is being made toward better utilization of unusual fuels, such as pulverized anthracite culm, lignite, acid sludges, and black liquor, the latter of which is obtained in the process of manufacturing kraft paper.
Improvements in electrical equipment for industrial plants include metal-clad switchgear, which may be located in any available space; also, air circuit breakers for voltages up to 5000 may soon be available in order to eliminate the fire hazard from using oil. Modern insulation on wire and cable offers greater resistance to high temperatures and the effects of moisture and other harmful substances.