1Department of agrotechnology, College of Abouraihan, University of Tehran, Tehran, Iran
2Department of Agronomy and Plant Breeding Science, College of Abouraihan, University of Tehran, Tehran, Iran
Determination of physical properties of municipal waste compost is necessary to obtain the parameters related to designing and constructing a suitable pelleting machine for producing compost pellets. The purpose of this study is determining some physical properties such as; bulk density, coefficient of friction, porosity, angle of repose for compost and density and expansion for compost pellets. These parameters are determined at three moisture content level (15, 20 and 25 %), four particle sizes (normal size, 10, 30 and 100) and three pressure level (23.4, 36 and 47.7 MPa) with three replications. According to the table of analysis of variance (ANOVA), effect of mesh size on angle of repose using emptying method was significant, but for filling method was not (P=0.01). The effect of mesh size on friction coefficient using four surfaces, was significant (P=0.01). It was determined that the effect of particle size, moisture content and pressure on density of pellets was significant (P=0.01). Also using compost with low porosity, particle size at 100, moisture content at 25% and pressure at 47.7 MPa will results producing best pellets.