summary “grain cleaning machine”. The invention proposes a grain cleaning machine (10) comprising a wrapper (12) having an inlet opening (13), a screen arrangement disposed internally to the wrapper (12) and a vibration system configured to oscillate the screen arrangement. . the sieve arrangement comprises at least two main sieve levels (14a, 14b, 14c), positioned superimposed with one another and inclined with respect to the horizontal from a high side (l1) to a low side (l2) each main sieve level (14a, 14b, 14c) comprising a respective fines sieve (141) followed by a respective grain sieve (142), and below each fines sieve (141) a respective fines guide rail is arranged (143) in communication with at least one waste outlet smaller than the grains (18) and below each grain sieve (142) there is arranged a respective grain guide rail (144) in communication with at least one grain outlet ( 19). the sieve arrangement further comprises at least one lower sieve level (16) comprising a respective lower grain sieve (162), and below the lower grain sieve (162) is disposed a lower grain guide rail (164) at communication with at least one grain outlet (19). the respective lower sieve level (16) is positioned below the respective main sieve levels (14a, 14b, 14c) and inclined from the horizontal from high side (l3) to low side (l4), with the low side (12) of each main screen level (14a, 14b, 14c) is in communication with the high side (13) of the respective lower screen level (16) through a vertical passage (17) and the low side (14) of the lower sieve level (16) is in communication with at least one waste outlet larger than the grains (20). 1/1resumo “máquina para limpeza de grãos”. a invenção propõe uma máquina para limpeza de grãos (10) compreendendo um envoltório (12) tendo uma abertura de entrada (13), um arranjo de peneiras disposto internamente ao envoltório (12) e um sistema de vibração configurado para oscilar o arranjo de peneiras. o arranjo de peneiras compreende a
