Enhancement of efficiency of fragment of suspension materials under the aerodynamic and electrical properties complex

Abstract

Increasing the yield of grain crops by improving the quality of seed material is an urgent task. One of the directions of its solution is the further improvement of technologies and equipment for the separation of grain material on the fraction most valuable of which is seed. The most common and commonly used pneumatic separators allow the separation of aerodynamic properties, which most closely correlate with the quality of seeds (size, weight). But the removal of the "defective" part of the seed, which has nominal aerodynamic characteristics, remains an unresolved problem. One of the promising ways to solve it is the use of electrical technologies.

Application of additional influence of an electric field allows by means of pre-equipping grain separators with electric working organs, realization of separation of grain material and electrical properties, which will significantly increase the quality of seed material.

At present, high-efficiency machines for cleaning and separating grain with air streams are developed; in vertical, inclined and horizontal channels. In this case, the dependence of the electrical properties of the grain on the biological state (biological activity) was detected. The analysis has established that using the electrostatic field and the difference in electrical and mechanical properties of grain mixtures particles, we can create a fundamentally new aerodynamic separation technology in pneumatic separators. In order to identify the feasibility of combining pneumatic and electrical working bodies, it is necessary to theoretically determine the laws of the displacement of components in the aerodynamic and electric fields.

The principal scheme of separation of components of grain material in the air flow when separated in the electrostatic field before feeding into the air stream is shown in Fig. 1

The equation of motion of a particle on the outer surface of the drum will be determined from the following references: the particle is located on the surface of the rotating drum in the room or can move along the surface, which depends on the surface condition and the properties of the material of the particle.

Under certain conditions, the particle loses its connection with the surface of the drum and separates it from it. Under conditions N=0, the particle will break off from the surface and will move in the air as a body thrown at an angle α₀ to the horizon at a rate V₀.

As follows from the analysis of studies of various authors, the greatest branching of trajectories is achieved at different values of the complex parameter μ (ie, different properties of the components). To increase the efficiency of further separation it is advisable to use a moving air-horizontal flow of air at a speed V_n.

The motion of components of grain material in the horizontal air flow after climbing from the surface of the drum is described by a system of differential equations.

For each current moment of time τ_i, the coordinates of the particle displacement correspond to the coordinate x_i(τ_i), y_i(τ_i) of the coordinate system of the coordinates X0Y, and when determining their significance, a trajectory x_i(y_i) of motion is constructed.

Conclusions

1. The combination of the processes of separating the components of seed materials by the complex of electrodynamic and aerodynamic properties will significantly improve the quality of the seed material "by" removal from fractions of inferior grains.

2. Increasing the quality of separation is also achieved by the fact that each component of the mixture is introduced into the air stream at different angles and at different speeds.

3. The simplified mathematical formulas obtained allow us to analyze the processes of movement and division of components at the stage of designing new equipment and to identify rational parameters and operating modes.