Optimal energy management in grain drying

Abstract

Grain drying is very specific to the geographic location, kind of drying system, and the type of grain. Under a given set of conditions, the optimal system can be selected based on careful evaluation. However, a good choice of drying systems, procedures, and management practices can be made from the information already available. The review of several grain-drying procedures has provided some insight in making a quick evaluation of the process and arriving at the most suitable system for a particular application. Despite extensive research efforts, the present knowledge of grain drying is yet insufficient to optimally design each drying process with respect to capacity, quality, and energy requirement. There is a need for incorporating grain and air parameters more accurately. It is also important to develop comprehensive drying simulation models to encompass agronomic practices, such as planting and harvesting. Recent efforts indicate a strong influence of planting and harvesting strategies on optimal drying and storage system selection. Results of the varietal trials at Ohio State University indicate that it is now possible to select midseason varieties, which dry down rapidly, without sacrificing yield. Also, low moisture at harvest is important to the energy management process because it affects total drying time and energy required. It is also important from a quality standpoint because kernel damage increases rapidly at harvesting moisture levels above 25%. The trend in grain-dryer design has shifted from focusing on drying capacity and operation reliability to energy consumption. The development in design of energy efficient continuous-flow dryers has been significant. Multistage concurrentflow dryers are excellent examples. Various aspects of dryer staging for efficient operation and control are yet to be determined. Recirculation of the exhaust air is a proven method of improving energy efficiency. Likewise, in batch-in-bin systems, stirring and intermittent drying are worth considering. Further research is required to formulate the best procedures for exhaust air recirculation and intermittent drying. Low temperature drying has a great potential in the U.S. corn belt. The suitability of low temperature drying at other places and for grains other than corn has not yet been well established. Energy savings resulting from low temperature drying entail careful planning and management on the part of the operator. Poor design and operation can result in a serious deterioration in grain quality.(ABSTRACT TRUNCATED AT 400 WORDS)

Microwave-Vacuum Drying of Cranberries: Part I. Energy Use and Efficiency

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