GB516339A - Method of and apparatus for grinding waste materials containing animal and/or vegetable matter - Google Patents

Abstract

516,339. Ball mills. PETERSEN, K. March 23, 1938, No. 8960. [Class 59] A method of grinding refuse in a rotating or oscillating screened drum, the material insufficiently ground to pass through the screen is transferred to an elevating device revolving with the drum which is adapted to return or advance the material for further treatment or to discharge the material from the drum. As shown in Figs. 1, 2 the drum comprises end plates 1, 3 connected by longitudinal bars 43 the periphery of the drum being formed by angularly bent grid bars 45 connected to the bars 43. The drum is separated into compartments by lifting chambers 39, 41 which may have central plates 61, 69 rotatable on a shaft 65 adapted to be turned through 180‹ when it is desired to return the material back into the compartment. Conical sieves 71 surround each compartment and the material left on each sieve is discharged through orifices 49 into the adjoining lifting chamber. Material is fed by a scoop 27 into a hopper 21 and the material passing through the sieves is discharged by lifting vanes to a conveyer. In a modification a discharge cone 57, Fig. 1, in the lifting chamber may be pivoted on a radial bar operative from the periphery of the drum so as to return the material to the grinding compartment. In Figs. 5, 6 the sieve 171 returns material thereon into a lifting drum 27 which discharges the material into a hopper 93, Fig. 6, adjoining the main hopper 121, the latter being provided with a removable cover 89. The lifting chamber may be arranged at the opposite end of the drum, the sieve being inclined in the reverse direction to that shown in Fig. 5. Specification 492,213 is referred to.