Energy-saving drying and its impact on corn kernel quality

Abstract

Purpose and objective. The study purpose was to characterize the existing approaches to energy saving in chamber dryers, to evaluate the effect of a new method, which includes drying with use of alternative energy resources (plant fuel) on the technological, sowing and yielding properties of kernels of corn hybrids and their parents.

Materials and Methods. Energy-saving drying by the new method was carried out under the factory conditions of the State Enterptise Experimental Production Farm “Dnipro” and OOO “Ahrosfera” (Dnipropetrovsk region).

Seeds dried inside at 20–25°C and in a laboratory dryer at 38°C and forced air ventilation were taken as control. The following quality indicators were examined using the standard method and cold germination: the water content in grain and stems, 1000-kernel weight, thermal fissureness, germination energy and germinability. The water content in grain was determined by drying samples weighing 5 g in a SESH-3M drying oven at 130°C for 40 minutes. For corn grain with a water content of over 18%, two-stage drying was used with preliminary drying of the sample. Thermal and mechanical fissureness was determined by the method developed in the Institute of Agriculture of the Steppe Zone of NAAS of Ukraine.

Results and Discussion. In the process of post-harvest treatment of corn kernels, thermal drying of wet cobs is the most energy-consuming technological operation, on which the seed quality depends. A list of existing methods for energy-saving in the drying process in corn chamber SKP dryers is given; their effects on the corn kernel quality were assessed. The methods include two-stage drying of cobs with grain drying, returning of the spent coolant to the drying zone (recirculation), and use of maximum permissible temperatures of cob heating. Coolant reversal and recirculation are of the greatest practical importance, since they reduce fuel consumption by 20–26%, fully preserving the kernel quality, and do not require significant technical and technological re-equipment of chamber corn driers. The fundamentally new trends in energy-saving with the use of plant fuel and heat generators for combustion have been defined.

Conclusions. The effect of the new drying method on the technological, sowing and yielding properties of seeds of kernels of corn hybrids and their parents was studied. The new drying method had no negative effect on sowing and yielding properties. The laboratory germinability of the tested hybrids was 95–98%, which corresponds to the established standards.