Abstract
1) Fertilizer in the top-delivery hopper flows up almost as the streamline flow of liquid. But, as shown in Fig. 1, during flowing occurs the compression of fertilizer (Fig. 2), and near the hopper wall, there takes place the relative delay of flowing speed of fertilizer particles, which is due to both the wall effect on the porosity in case of packing and the compress ibility of fertilizer.
2) The higher the fluidity of fertilizer is, the larger the pressure of fertilizer on the bottom plate is Fig. 3). The change of this pressure during flowing reflects the cohesiveness of fertilizer.
3) The real discharge volume from the hopper is always less than the theoritical nearly in proportion to the degree of the above compression, (Fig. 4), so that it is expressed in equation (1).
