TY - JOUR
TI - Investigation of maize cobs crushing: Preparation for use as a fuel
AU - Martinov Milan
AU - Veselinov Branislav
AU - Bojić Savo
AU - Đatkov Đorđe
JN - Thermal Science
PY - 2011
VL - 15
IS - 1
SP - 235
EP - 243
PT - Article
AB - Maize crop residues have great significance, particularly in developing  countries, where the harvest of maize ears and their natural drying is widely  applied. After drying and grain threshing, maize cobs are available for  energetic use on farmers’ yards. Shortcomings for their energetic utilization  by combustion, in comparison with wood, are higher contents of potassium,  chlorine and nitrogen, and lower ash softening point. Tests in small wood  chip boilers showed that the size of maize cobs should be reduced in order to  facilitate better combustion and feeding with commonly used screw conveyors.  Desirable length of particles should be 1-1.5 of their diameter. Within the  framework of the Eureka project, a low-cost maize cobs crusher was developed  and tested. It consists of a drum with six rows of knives, stationary  comb-like knives and a screen situated below the drum. The test resulted with  working parameters that enable appropriate size reduction. Analyses of  crushed material showed that over 80% of particles were in the range of  3.15-45 mm, less than 1% smaller than 1 mm, and less than 1% larger than 63  mm. This granulation is comparable with size class P45 for wood chips in  accordance with standard DIN CEN/TS 14961. Further investigations should  focus on improving the combustion facilities, in order to avoid formation of  ash slag, and keeping exhaust gas characteristics within values defined by  legislation.