Abstract: Method for the preparation of finely divided calcium hydroxide, where calcium oxide is comminuted in an impact disintegrator into which in addition to the calcium hydroxide a small amount of water is led to wet the particles obtained and to bind the dust. The calcium oxide powder is led to a conveyor being in connection with the impact disintegrator and operating as a pre-quencher, to which conveyer water is added and where the material is subjected to a kneading effect. The material which is a mixture of calcium oxide and calcium hydroxide is led from the conveyor to a cistern operating as post-quencher, to which cistern the remaining portion of the total water amount required for quenching is added. The amount of water added to the impact disintegrator and to the pre-quencher is altogether 20 . . . 50% of the total amount of water required for quenching, preferably about ? of the total amount of water required for quenching, and the amount of water added to the post-quencher is 80 . . .

Abstract: An impact mill equipped with transmission machinery (10) to rotate two coaxial rotors (16, 18) of a rotor apparatus (12) by one single driving apparatus (14). The transmission device includes, according to one alternative, a secondary shaft (32; 36b) equipped with a gear pair (28, 30) or a conic gear (29). The first gear (28) rotates a gear (24) at the shaft (20) of the first rotor (16), and the second gear (30) rotates a gear (26) at the shaft (22) of the second rotor (18), but in the opposite direction or at a different speed. The conic gear (29) rotates the gear (24a) at the shaft (20) of the first rotor (16) in one direction, and the gear (26a) at the shaft (22) of the second rotor (18) in the opposite direction.

Abstract: An impact mill equipped with transmission machinery (10) to rotate two coaxial rotors (16, 18) of a rotor apparatus (12) by means of one single driving apparatus (14). The transmission device includes, according to one alternative, a secondary shaft (32; 36b) equipped with a gear pair (28, 30) or a conic gear (29). The first gear (28) rotates a gear (24) at the shaft (20) of the first rotor (16), and the second gear (30) rotates a gear (26) at the shaft (22) of the second rotor (18), but in the opposite direction or at a different speed. The conic gear (29) rotates the gear (24a) at the shaft (20) of the first rotor (16) in one direction, and the gear (26a) at the shaft (22) of the second rotor (18) in the opposite direction.

Abstract: A method and apparatus for treating materials or material mixtures in a treatment apparatus operating on the principle of the double-action impact mill, which includes a discharge conveyor (34), such as a discharge screw. A material layer (40) is maintained between the discharge opening and the discharge conveyor, using the material exiting the outermost ring (16?) of the treatment apparatus through the discharge opening (30), which layer prevents free discharge of the material to be treated from the treatment apparatus.

Abstract: A method and apparatus for treating materials or material mixtures in a treatment apparatus operating on the principle of the double-action impact mill, which includes a discharge conveyor (34), such as a discharge screw. A material layer (40) is maintained between the discharge opening and the discharge conveyor, using the material exiting the outermost ring (16?) of the treatment apparatus through the discharge opening (30), which layer prevents free discharge of the material to be treated from the treatment apparatus.

Abstract: A method and apparatus for biological and/or chemical decomposition of waste containing organic matter. The method includes waste pretreatment in which waste is fragmented and homogenised in a pretreatment apparatus (10a, 10b) operating on the principle of a multi-ring double action impact mill. The apparatus has either two rotors (62, 64) or a rotor and stator disposed inside a housing (26), which rotors and/or stator are equipped with blades having impact surfaces, and which form one or more rings (1,2,3, . . . ) coaxial with the rotor. The waste is fed into the housing through the hub of rings formed by the blades, and travels by the effect of a rotor or rotors, to the outer ring of the ring (7) formed by the outermost blades, and further to the discharge opening (25, 27?) at the outer ring.