## 3 Results and Discussion  
### Experimental Unit Design Characterization  
According to Figure 2, the experimental press consists of the following main parts: a cylindrical body 1, a hopper 2, and a drain pan for collecting the liquid fraction 3. The cylindrical body 1 consists of grinding and pressing chambers. The grinding chamber is constructed of a conveying screw 4 and a grinding mechanism comprising a receiving plate 5 and a grinding plate 6, a knife 7, and a ring 8 mounted on the outside of the knife (Figures 3-5). Three holes are cut on the receiving plate 5, and the holes are made in the direction of the raw material flow. Figure 3: Conveying screw. Figure 2: Schematic diagram of the oil screw press. 1—cylindrical frame; 2—hopper; 3—tray for collecting liquid fraction; 4—conveying screw; 5—receiving plate; 6—cutting plate; 7—knife; 8—ring; 9—pressing screw; 10—Zeer cylinder; 11—diaphrag cone grating; 12—clamping nut; 13—electric motor; 14—worm gearbox; 15—V-belt transmission; 16—chain transmission; 17—bearing support; 18—base. The constructed grinding mechanism is a multi-pass screw-shaped knife, of which the angle of the screw lines elevation is in the range of \(15\div 45\) degrees (Figure 6). Its design consists of two cutting edges 1, 2; front surface 3; and pressing and forcing surfaces. The length of the knife rotation axis is taken equal to one-third of the knife diameter and greater than the width of the outer ring. Figure 4: Receiving plate. Figure 5: Grinding plate set. The pressing chamber consists of a Zeer cylinder 10 and a pressing screw 9 installed therein (Figures 7 and 8). The press chamber is made collapsible for easy disassembly of the press due to the difficulty of sanitary treatment of the Zeer cylinder 10. The pressure on the oilseeds is produced under the influence of the sequential increase in the diameter of the shaft of the pressing screw 9 in the direction of seed movement. The pitch of turns of the pressing screw 9 is constant, and the thickness of the turns is uniformly and consistently increased in the direction of the product movement. A uniform pitch of the screw guarantees constant equipment performance, and a uniform and sequential increase in the thickness of the screw in the direction of product movement increases the strength and reliability of the design. On the inner surface of the Zeer cylinder, grooves are cut for the flow of the liquid fraction through the holes, providing resistance to the rotation of the cake together with the screw and improving its transportation. At the end of the cylindrical body, a diaphragm cone and a tightening nut are installed (Figure 9). Holes are made in the diaphragm cone for thermoplastic molding (granulation) of the cake. According to Figure 10, the press drive consists of an electric motor 13, a worm gearbox 14, and a V-belt transmission 15. The worm gearbox 14 is connected to the tail bearing support 17 via the chain transmission 16. The shafts of the press are connected to the tail bearing support, which is fixed to the welded frame 18. During the research, the speed of rotation of the shafts was changed by changing the pulleys of the V-belt transmission. Figure 8: Zeer cylinder. Figure 7: Pressing screw. The press works as follows: sunflower seeds are loaded into hopper 2, from where they enter cylindrical body 1 with cut grooves, and are transported by screw 4 to the grinding mechanism, where they are ground. The ground meal passing through the pressing chamber is pressed by pressing screw 9. The oil separated from the cake, through the holes located in the grain cylinder 10 and cylindrical body 1, drains into a ray 3 for oil collection, installed in the lower part of the cylindrical body. The pressed cake in granulated form is removed through an adjustable conical grate (Figures 11 and 12). The obtained sunflower oil by organoleptic and physicochemical indicators meets the requirements of normative documents for vegetable oils.