Dynamic Arches Destruction by a Bulk Material Flow Separator: A Case Study of the Separator Usage in Microwave Grain Processing Plants

Abstract

Hoppers for unloading bulk materials are an indispensable feature of many technological machines and not only those employed in agricultural production. One of the problems in the operation of hoppers is the appearance of dynamic arches which make the outflow of grain uneven. Experimental studies have previously shown that the formation of dynamic arches creates an uneven outflow of grain along the vertical zones of outlet hoppers. This can lead to the processing mode violation of bulk material and loss of machine productivity. This paper theoretically shows that the use of arch-breaking devices with an element oscillating in the grain layer requires systems for automatic adjustment of oscillation frequency. This complicates the design and makes it more expensive. It is proposed to amend the type of material outflow as it moves along the hopper’s height to solve this problem. The possibility of employing this approach has been tested on the use of a bulk material flow separator in the outlet hopper. The bulk material flow separator is made in a plate form and is installed rigidly between two opposite walls of the outlet hopper. Thus, the volume of the hopper is divided into two vertical equal parts. With the help of experimental studies, it was determined that the lower side of the bulk material flow separator should be at a distance of 0.3 of the total hopper height from the discharge opening, while the upper side of the separator should be at a distance of 0.25 of the hopper’s height from the top edge of the hopper. The experimental verification of flow separator use confirmed its effectiveness.

Using Modeling to Select the Type of Microwave Field Emitter for Dense-Layer Grain Dryers

“…Previously, the authors designed a shaft-type convective-microwave dryer on the basis of a processing unit in which microwave field sources were installed on the opposite sides of the grain processing zone [23,24] (Figure 1). The unit in the processing plant had the following dimensions 0.3 × 0.2 × 0.2 m, and the volume of the inner space was 0.012 m 3 .…”