Pressing technology and burning quality of spherical fuel briquettes made from autumn leaves

A process has been developed to press fuel briquettes from autumn leaves. It has been shown that a spherical shape of a briquette is optimal since even dense packing of balls provides air access to each individual ball. This is especially important in the initial phase of burning when briquettes touch each other and gain a certain temperature, because of the quality of burning increases. The technology of briquette pressing has been devised. We studied dispersion of particles of dry leaves of nutwood, maple, and oak after grinding and found that particle size distribution of powders of different leaves is not the same, and their bulk density is proportional to size with the highest content. A new method for pressing briquettes in a round closed matrix has been proposed. The difference of the method is in the fact that the process takes place at the creation of a scheme of all-embracing uniform compression with a spherical application of force and obtaining of a ball-shaped briquette in the final phase. The method makes it possible to compress ground leaves radially and evenly and thereby to ensure equal burning conditions for a briquette in a radial direction from any point on the periphery. We derived a mathematical model of the dependence of the density of dry briquettes on the bulk density of ground leaves and the degree of compression of a briquette. It has been shown that the bulk density of ground leaves (65%) has the greatest influence on the density of dry briquettes. An increase in the bulk density of ground leaves leads to an increase in the density of dry briquettes. The influence of the degree of compression of a briquette is much smaller (35%) but it is significant. Its increase leads to an increase in the density of dry briquettes. The density of dry briquettes was from 0.67 to 1.07g/cm3during studies. We proposed a design of a round closed matrix with a variable wall thickness, which makes it possible to reduce its metal consumption and cost by 20‒30%. It has been shown that it is expedient to use spherical briquettes of leaves as an alternative environmentally friendly fuel