Experimental testing of a helical rotor for compost distribution

Abstract

It is well known that a manure spreader must be able to apply manure consistently, effectively and uniformly over the time. An overapplying doze will cause serios environmental problems (pollution) and a sub-applying doze will not contribute to plants growth and the applying of the fertilizer will be a loss. Corroborate with others problems such as maintaining a constant tractor speed, a constant rotational speed of the rotor, a constant and continuous flow of the material make the manure spreading machines an important subject for study and continuously improving . The propose of this study is to test a vertical helicoidal rotor for manure spreading in order to improve the machine distribution uniformity. The relation between the rotor position and rotation sense is a definitory issue for the machine performance. In order to achieve a high distribution uniformity a single helical rotor is tested and a series of possible situations of placing four rotors on the machine are analyzed. The optimal solution is given by two indicators: uniformity of spreading and distribution width. The test were made with an helical rotor having the following characteristics: high=1,1 m, maximum diameter of helical spiral=0.345 m, minimum diameter of the helical spiral= 0.114m, helical pitch=0.3m, inclination angle = 15°. After analyzing four possible situations it is observe that the combination of the maximum uniformity with minimum distribution with is the optimal solution. Experimental were carried out with compost and can be repeatable with others type of solid organic fertilizers, but a new calibration should be done. It is desirable that a trapezoidal, oval or triangle pattern with uniform sloping sides to be achieved. Because most of the spreaders actually produce an oval or triangle distribution pattern it is necessary subsequent passes that increase the time for fertilization operation.