Grate arrangement for a furnace, the grate arrangement comprising
- a fixed step frame with supporting members;
- a movable step frame with supporting members, the movable step frame configured to drive in a reciprocating motion in a longitudinal direction;
- a first arrangement comprising a non-driven horizontal row of fixed grate bars and movable grate bars, the fixed grate bars being fixed with respect to a supporting member of the fixed step frame and the movable grate bars being movable in the longitudinal direction with respect to a supporting member of the fixed step frame;
- and
- a second arrangement comprising a driven horizontal row of fixed grate bars and movable grate bars, the fixed grate bars being fixed with respect to a supporting member of the movable step frame and the movable grate bars being movable in the longitudinal direction with respect to a supporting member of the movable step frame, the second arrangement of fixed grate bars and movable grate bars vertically overlapping the first arrangement of fixed grate bars and movable grate bars;
- the fixed grate bars and the movable grate bars comprising a first lateral side, a second lateral side, and an upper surface, the second lateral side being opposite to the first lateral side and the second lateral side facing into a direction that is opposite to a direction in which the first lateral side is facing, each of the fixed grate bars placed horizontally adjacent to a one of the movable grate bars,
- the upper surface of each grate bar being provided between the first lateral side and the second lateral side of each grate bar, wherein the first lateral side and the second lateral side are integrally formed with the upper surface and are separated by the upper surface,
- each of the fixed grate bars and the movable grate bars further comprising:
- a first elongated recess and a second elongated recess defined at the first lateral side, each of the elongated recesses having two parallel sliding surfaces and defining a height as a distance between the two parallel sliding surfaces,
- and
- a first engaging element and a second engaging element, the first engaging element and the second engaging element disposed on the second lateral side, each of the engaging elements defining two parallel sliding surfaces and defining a height as a distance between the two parallel sliding surfaces, the engaging elements of each grate bar engaging into the corresponding elongated recesses of a neighbouring grate bar, wherein the elongated recesses define a longitudinal dimension such that the engaging elements are longitudinally movable in the elongated recesses, wherein the two parallel sliding surfaces of the engaging elements are oriented in the longitudinal direction of the grate bars, and wherein the engaging elements positioned in the respective elongated recesses define a maximum tilting angle at which the two parallel sliding surfaces of the engaging elements are non-parallel with the two sliding surfaces of the elongated recesses and at least one of the first engaging element and the second engaging element contacts the two parallel sliding surfaces of the corresponding elongated recess of the neighbouring grate bar at two opposite edges of the engaging element, wherein the maximum tilting angle is determined by a height difference between the height of a respective elongated recess and the height of a respective engaging element and by a geometrical shape of the respective engaging element.