Not all materials can be transported using an automatic feeding machine. The transportability of materials can be determined by measuring and analyzing some characteristic parameters of the materials. The characteristic parameters of the automatic feeding machine include: stacking angle, stacking density, particle factor, electrostatic constant, moisture sensitivity, explosion risk, toxicity, and corrosiveness.

(1) The stacking angle is one of the important parameters when determining the transportability of a material, and the flowability of the material is also a critical factor. The stacking angle is usually used to represent the angle between the cone surface formed by the material falling from a certain height and the horizontal plane. The smaller the angle of the automatic feeding machine, the better the fluidity, and vice versa. However, for certain special materials, the stacking angle cannot accurately indicate the quality of fluidity.

(2) Bulk density refers to the weight per unit volume of a material in a loose state. Due to the presence of materials and air in particles or powders, the bulk density may vary depending on the stacking form, therefore it is necessary to measure the bulk density in its actual state.

(3) The weight, particle size distribution, shape, and hardness of particles are key factors affecting material flowability and conveying system design.

(4) Moisture sensitivity: All materials have moisture absorption characteristics. For moisture sensitive materials, their flowability may change due to moisture absorption and agglomeration, and they may even adhere to the pipe wall or filter surface, resulting in blockage of the pipe or filter.

(5) Explosion risk: When fine particles mix with air and reach a critical concentration, there is a possibility of explosion once sparks appear. There are several necessary conditions for dust explosion: oxygen, critical concentration, and spark. It is difficult to control the concentration of materials during automatic feeding, and only oxygen and sparks can be controlled. By using inert gas protection to isolate oxygen and eliminating static electricity to avoid sparks, the risk of explosion can be controlled.