Electrical Energy Management in the Cement Industry
A cement plant uses about 150 kWh of electrical energy per metric ton of cement produced. Where is this electrical energy being used? How is it being used? Can it be utilized more effectively? If so, how? What can be done to conserve the electrical energy used in an existing cement plant and in future cement plants? An electrical energy management program to resolve these questions is presented. Included is an electrical energy consumption survey of five cement plants. Department consumption is tabulated, and suggestions are made to conserve electrical energy and reduce cost of electrical power in both new and existing plants.
Are Energy Management Systems Cost Effective?
While the market for energy management systems (EMS) has been exploding, there are many indications that the pendulum of high expectations may have swung too far. A simple seven-day time clock can usually provide 80-95 percent of the potential savings of many EMS features. For several hundred additional dollars, a small microprocessor based time clock with features such as automatic holiday and daylight savings adjustments, optimal start, and four separate load stop/start schedules (ventilation, heating, and air conditioning, indoor lights, and outdoor lights) can be purchased which can increase the savings an additional 5-20 percent on most buildings. Owners of multiple building systems or large commercial and industrial buildings can often justify a complex EMS with increased load scheduling capability. However, EMS features such as duty-cycling and demand limiting are usually overrated in their energy savings capability, not only because slowing down the fans can save more energy than cycling them, but also because duty cycling can cause personnel discomfort and equipment maintenance problems. Moreover, any temperature control modifications which save energy can usually be installed without an EMS for less initial cost and with an equivalent energy savings. Additional expenses for EMS features such as temperature monitoring and remote set point adjustment are not usually of value if a building's heating, ventilating, and air conditioning (HVAC) system is operating properly. EMS features such as metering and report logs can be useful diagnostic tools in the hands of a qualified individual, but often they provide data diarrhea.
Chemical Engineering and Thermodynamics applied to the Cement Rotary Kiln
THE cement industry, at a time of great prosperity, celebrated the centenary of the discovery of Portland cement by Aspin by abandoning its research association and allowing the scientific staff to dissipate ! Whatever the causes that led to this action, it can only be regarded with regret. Every industry sheltered by a tariff or existing as a monopoly has a national obligation from which it cannot escape. The country has a right to buy cement of the highest quality at the lowest price, equal in every way to that available throughout the world, and it is doubtful whether, under modern conditions, fundamental advances can be achieved without the daily aid of applied science.Chemical Engineering and Thermodynamics applied to the Cement Rotary Kiln.Dr. Geoffrey Martin. Pp. xv + 244. (London: Crosby Lockwood and Son, 1932.) 31s.