# Energy Saving in Electromechanical Grain Cleaning Systems
## 4 Discussion  
The SEC on the production lines was obtained while cleaning wheat of varying humidity within the range of 11-17%. The experimental research on ZAV-20 has shown that with a 1% increase in grain humidity the SEC of production lines increases by an average of 10-12%, as the weight by volume of grain decreases with an increase in grain humidity. At the same time, the capacity of the production line decreases by an average of 0.3-0.5 t/h. The SEC for cleaning one ton of seeds is higher than for cleaning one ton of food grain by an average of 18-20%. The workflow of post-harvest processing of food grains and seed grains is carried out through systems of machines and installations, which can be distinguished as main and supporting ones [47]. The main machines gradually process the raw material to final product status. These are the separating machines. Supporting machines do not change the quality of grain but are used to help the main ones. These include transporters and car lifts. While building the production lines, only the passport capacity of machines is considered, which is indicated when working with wheat of normal humidity (up to 15%) and average dockage (up to 5%). The actual dockage of the grain arriving for cleaning includes straw impurities--up to 8%, weed seeds--up to 5% and soil--up to 2%. The operating experience of the ZAV-20 grain-cleaning machine [1] shows that, as a rule, the capacity of grain cleaning equipment is below nominal values by 30-60%. The reason for the low capacity lies in organizational, technical and technological deficiencies. Organizational and technical deficiencies can be addressed as operating experience is gained and the equipment of the grain cleaning operating line is upgraded. The decline in the capacity of the operating line for technological reasons is mainly related to the probability of grain flow and the grain cleaning process. One of the main factors limiting the machine's capacity is the quality of grain cleaning, which in turn influences the uniformity of the machine load. The obtained data indicate that 50% of ZAV's operating capacity is used. Large deviations from the nominal values for loading the electric motors of individual ZAV machines (17-57% in power, 44-90% in current) indicate the need for further improvements in the design of the machines and possible coordination of their operating performance [1]. It has been established that the actual capacity of the production lines is lower than the nominal capacity of any of the machines forming it. It decreases with an increase in the number of machines in the production line and the variability coefficient of its performance. The key and indispensable factor for the most economical operation of the production line is the same nominal capacity of all the machines and mechanisms connected in a series and forming the line. Otherwise, the production line capacity will be determined by the machine with the lowest nominal performance. The experimental data underwent a thorough analysis. The influence of many production and physical factors on the specific electricity consumption can be considered by utilizing mathematical tools and using probability theory and mathematical statistics involving the application of computer software. Based on the calculations, mathematical models were obtained that relate the specific energy input to the production line capacity, humidity and grain dockage (Equations (2) and (4)). Through the regression equations obtained from this stage of the research, it is possible to determine the SEC of grain cleaning by different technological schemes with varying physical and mechanical properties of grain. This enables grain cleaning with minimum SEC. For each grain cleaning production line of the ZAV-20 machine, nomograms of electric consumption are proposed (Figures 3 and 4) which are characterized by legibility and convenience in selecting the optimum load of production lines with the minimum SEC (Quadrant 1) at different humidity and dockage values.