How does the (BS) Mark 5 air-cooled w-grate work?
The w-grate resembles a staircase. The individual steps, the grate bars, are alternately placed horizontally and vertically. These grate bars are mounted on shafts. As the grate bars of one shaft interferes with the bars of the adjoining shaft, a continuous grate carpet is formed. When the shaft turns 60º in opposite directions during movement of the grate, the steps change from vertical to horizontal and from horizontal to vertical.
The changing of the steps from horizontal to vertical and vice versa produces a wave-like longitudinal movement. This produces optimal turnover of the fuel bed.
Details of the BS Mark 5 grate
- The driving mechanism situated outside the furnace provides an approx. 2 mm gap between successive grate bars in all shaft positions. Combustion air is added through these gaps.
- A grate consists of modules which can be combined into grates of various lengths and widths without any limitations.
- The grate is placed at a 25º inclination.
- There is no physical contact between individual bars during movement.
- The grate is formed by independent sections. The ends and sides of the bars are machined to ensure correct length and width.
- The individual sections can be operated independently of one another at a velocity adapted to the energy release.
- Each grate section is equipped with a complete driving mechanism, including double-acting hydraulic cylinders.
- The driving mechanism also ensures that the gap between two subsequent grate bars remains constant during grate movement.
- Primary combustion air is added individually through each grate section as needed.
