GB462075A - Improvements in and relating to rotary grates, particularly applicable to the furnaces of steam generators or the like - Google Patents

Abstract

462,075. Rotary grates. SCHMIDT'SCHE HEISSDAMPF-GES. Jan. 20, 1936, Nos. 1835 and 1836. Convention dates, Jan. 19, 1935 and April 16, 1935. [Class 51 (i)] A rotary grate comprising at least two superposed discs rotatable about different axes is fed with fuel near the centre or periphery of the upper disc and the fuel moves outwardly or inwardly over the disc in a spiral path on its way to the lower disc or discs. Figs. 1 and 2 show diagrammatically two methods of causing the fuel to follow a spiral path on the upper rotary grate disc. According to Fig. 1, the fuel is fed by a vertical shoot 2 at the centre of the grate disc 1 and during rotation of the disc the fuel is piled up against a wall 3 to form an obstruction which deflects the oncoming fuel outwardly at d and subsequently at e, the fuel being finally discharged at f. Fig. 2 shows a modification wherein the shoot 2 is arranged eccentrically to the grate disc 1 and the fuel itself forms a barrier which deflects the oncoming fuel and causes it to move in a spiral path. Fig. 3 shows a furnace grate in which an upper grate disc 1 rotates about an axis a, and a lower annular grate 4 rotates about an axis m. The axis of the fuel shaft 5 is at n and is angularly displaced in a direction opposite to the direction of rotation of the grate discs with respect to the line joining the axes a, m. The upper disc consists of grate bars 19, 21 and is driven by gearing from a shaft 29 and the lower disc consisting of bars 7 supported on rings 41, 4<11> is driven by gearing from a shaft 17. The outer edge of the upper disc is provided with teeth 31. The fuel residues are discharged from the lower disc through a shoot q which may be provided with a hinged flap at its inlet. The lower end of the fuel shaft is provided with an adjustable slide 35. Fig. 7 shows diagrammatically the spiral path of the fuel on the upper grate 1 when it is fed through a feed shaft 2 arranged at the periphery of the grate where is also arranged a barrier wall 3. The axis a of the grate may coincide with the axis of the firebox as shown or may be eccentric thereto in which case the wall of the firebox may be extended downwardly to the grate and form a deflecting barrier. Fig. 9 shows two superposed rotatable grate discs 1, 4 to which fuel is fed from the shaft 2, the axes of the grate discs being out of alignment with each other and with the central vertical axis of the firebox. The grate discs are rotated in the same direction by shafts 54, 55 end gearing 52, 53. A further modification comprises three superposed annular discs, the upper and lower discs being driven directly while the intermediate disc is connected by a link to the upper disc. With a number of grate discs, alternate discs may rotate about a common axis and the remaining discs about another axis. Various driving means for the grate discs may be employed.