A METHOD FOR PREDICTING THE RESULTS OF GRAIN SEPARATION AND CALCULATION OF THE MAIN PARAMETERS OF THE GRAVITY SEPARATOR

A new method for predicting the efficiency of the grain separation process is presented in the article. It is based on comparing the results of control sifting with the results of separation of the entire volume of material. The key element of the method is the calculation of the main parameters of the gravity separator, which is used in the process of separating the grain mixture. The proposed grain separation method is implemented by using a slit separating hole equipped with a brachistochronic acceleration surface. The grain mixture separation process is carried out as follows: particles are preaccelerated and then separated through slit holes. Particle acceleration occurs along brachistochronic surfaces, and preliminary separation occurs through the cracks between them. The width of these cracks should be at least 3-4 diameters of grains to ensure efficient separation. To achieve maximum efficiency of the separation process, a method for calculating the key parameters of the gravity separator has been developed. Within the framework of this method, the width of the crack (L) and the height between adjacent edges (H) of the brachistochronic surfaces are determined. The calculation takes into account the relationship with the equivalent diameter of grains and their speed achieved on the separating surfaces. The deviation of the theoretical values of the parameters L, H and the intensity of separation from the experimental data does not exceed 9% in the entire studied range of parameter variation, which indicates the high accuracy of the results obtained and the adequacy of the process modeling. This method of preliminary preparation of grain for separation, in which the bulk of the material is not exposed, with the exception of the selected sample, minimizes the risk of its damage. Moreover, this approach reduces the costs of adjusting the separator parameters, improves the quality of separation due to the precise predictability of the results and opens up new prospects for improving the designs of gravity separators.