Design of ordered fertilizer device for bagged slow-release fertilizer

By controlling the release rate of fertilizer nutrients, bagged slow-release fertilizer can reduce the amount of fertilizer application. In the past, the fertilization method of bagged slow-release controlled release fertilizer was mainly manual, high cost and low efficiency. In order to realize the mechanized application of bagged slow-release fertilizer, we measured its basic physical parameters and mechanical properties, based on the measured data, we had studied the ordered queuing mechanism, residual material cleaning and quantitative application of bagged slow-release fertilizer, designed a bagged slow-release fertilizer ordered fertilizer device, which was composed of an eccentric separating mechanism, a cleaning mechanism, a fertilizer discharging mechanism and a power transmission mechanism. We performed kinematic analysis on the eccentric separation mechanism, calculated the motion parameters of the vibrating plate by vibration principle, found out the factors affecting the movement of the bagged fertilizer, and verified the synonym of the motion parameters. Theoretical analysis showed that the eccentric speed should be in the range of 493.69-618.79 r/min. For the pre-test surface, the flexural strength of the fertilizer was suitable for mechanized discharge in the range of 198-318.34 mN·cm, took the eccentric wheel speed, the brush wheel speed and the distance between the brush wheel and the scraper conveyor belt as the influencing factors. The orthogonal index test was carried out with qualified rate, miss rate and repeat rate as the evaluation indicators. It established a mathematical model of influencing factors and evaluation indicators. We analyzed the response surface map，drove the relationship between influencing factors affecting the trend of the qualification index and the interaction of influencing factors. We used the Design-Expert software, and the optimal combination of parameters was obtained: the eccentric wheel speed was 600 r/min, the brush wheel speed was 95 r/min, and the distance between the brush wheel and the squeegee conveyor belt was 18 mm. Through the verification test, the average value of the qualified rate of was 82%, the average value of the miss rate was 9.33%, and the average value of the repeat rate was 8.67%. Main reason for fertilizer miss was that the fertilizer was oscillated by the eccentric separation mechanism, and its surface was not completely attached to the conveyor belt. When the brush wheel rotated, it was going to "returned" by friction. The main reason for fertilizer repeat was that the rate of vibration of the fertilizer was slightly larger than that of the conveyor belt, and the contusion between the brush wheel and the conveyor belt was prone to occurr, led to the discharge of fertilizers. The faster the eccentric wheel speed, the better the flow performance of the bagged fertilizer on the vibrating plate surface, which could effectively reduce the miss rate. At the same time, it was easy to cause congestion between the brush wheel and the conveyor belt, resulting in an increase in the repeat rate.This study provides a reference for the development of bagged slow-release fertilizers for the ordered application of fertilizers, however, the effect of brush length on cleaning effect is worth further study.