EVALUATION OF THE EFFECTIVENESS OF A MODERN SEED CLEANING LINE IN CLEANING ALFALFA SEEDS

Alfalfa seed crops are often infested with a parasite, dodder. The efficiency of a modern alfalfa seed cleaning line for removing hard-to-separate impurities, including the quarantine weed dodder, was studied. A process line consisting of an air-sieve separator (5XFS-7.5FC), a pneumatic table (5XZ-6 Gravity) and a photoseparator ("Sapsan SE") was used. 143 kg of combine heap of the "Planet" variety (2022) with an initial purity of 30% were analyzed. Samples were taken after each node, analyzed according to GOST 33735-2016, and the mass fraction of components was determined. After the air-sieve separator, the purity reached 94.6%, but seed losses were 24% (the main part being unthreshed beans and small seeds). The pneumatic table increased the purity to 99.98%, but the losses increased to 30%. The photoseparator ensured the purity of 99.99%, but single specimens of dodder seeds were found in the acceptable product (0.003% of the sample). The total loss of full-value seeds was 57.1%, of which 37% had a high weight (1.75–2.20 g/1000 seeds). It was found that single-channel aspiration and the absence of a final threshing unit lead to irretrievable losses of seeds in beans (10.8%). For efficient cleaning of alfalfa seeds, it is recommended to use a double-aspiration air-sieve separator at the primary cleaning stage, while large impurities must be passed through a clover threshing machine or a final threshing device, and the heap after final threshing must be re-directed for primary cleaning. This approach will avoid the loss of seeds contained in unthreshed beans. In addition, for effective cleaning of alfalfa seeds and complete removal of dodder seeds, it is necessary to carefully select the parameters of the working parts and operating modes of seed cleaning machines depending on the configuration of the heap entering the cleaning process.