Hammer crushers are widely used for the destruction of grain in feed preparation. When they work in the grinding chamber, as a result of the rotor’s rotation, air flows arise that involve particles of crushed material and whole grains in motion, thereby creating an air-productive layer. These air flows are influenced by the shape and geometrical parameters of the blades, their location, rotor diameter and speed, and the parameters of the separating surface. Under the conditions of Knyagininskiy University, a hammer crusher with an enlarged separating surface was developed, the working chamber of which was formed by two end and one peripheral sieves. Angle hammers, straight hammers, or a combination of straight hammers and corner blades placed between them were installed on the rotor as working units. The study was carried out to study the effect of the type of working units and the area of overlapping of the edge sieve on the direction of air flows in the grinding chamber and to determine the working area of the edge sieve. Angle hammers are characterized by the movement of air flows in the axial direction and their following distribution: suction into the grinding chamber in the central part of the end sieve and ejection along the outer circumference of the sieve. Based on this, the entire area of the end sieve can be divided into three parts: the suction zone, the ejection zone and the transition zone. An increase in the length of the angular blades leads to an increase in the working area of the end screens, therefore, the use of combined working units is rational. Installation of working units in the form of straight hammers is impractical, since the working area of the end screens is minimal. It is also irrational to use working units in the form of angle hammers, since they are characterized by the maximum area of the retraction zone and a small working area of the end sieves

Cereals are an integral part of the feed rations of farm animals. When dry feeding, the grains are crushed. Grain grinding can be performed in various ways, such as crushing, splitting, abrasion, and impact. Different equipment is used for this purpose: roller machines, mills, gear, disk and hammer crushers, etc. In Russia, the most common method of grinding grain in hammer crushers. The advantages of hammer crushers include their high reliability, simplicity of design and maintenance, while the disadvantages are high energy consumption for grain grinding and uneven granulometric composition of the finished product. Due to these shortcomings, it is important to improve the design of crushers in order to increase their productivity and reduce specific energy consumption. We have proposed a grain crusher with an increased separating surface. To study the crusher, its structural and logical scheme and research methodology were developed. In accordance with the developed scheme, the influence of the sieve area on the quantitative and energy performance of the crusher was studied, which is the purpose of this work. The research methodology was developed and a prototype of the crusher was made. The conducted research allows us to conclude that it is necessary to change the conditions for entering grain into the grinding chamber by increasing the area of the loading window, installing a mechanism for forced grain feeding or feeding grain through the center of the rotor. The throughput of end sieves when using a rotor with straight hammers is by 2…38% higher than that of peripheral sieves.