Why reciprocating grates are the preferred choice for burning poor-quality fuels

Among industrial combustion equipment the reciprocating grate suits the burning of poor-quality fuels, and this feature gives it wide use in handling high-moisture, high-ash, low-calorific-value fuels. The partner plant we work with has adjusted the reciprocating grate structure considerably in this direction and arrived at a grate form suited to such fuels.

Structural design and working principle

The advantage of the reciprocating grate comes from its structural design and working principle. An inclined reciprocating grate consists of moving grate bars and fixed grate bars alternately overlapped into a stepped grate surface, and the coal is pushed and tumbled by the reciprocating movement of the moving grate. This movement brings fresh coal into full contact with the coal already burning and improves the ignition conditions. During pushing it also squeezes and breaks coke lumps and ash shells, so the fire is stirred automatically and the problem of incomplete combustion of poor-quality fuels is eased.

Ventilation section ratio and stroke parameters

To meet the combustion requirements of poor-quality fuels further, the R&D team adjusted the grate bar structure, the ventilation section ratio and the movement parameters. The reciprocating grates it produces keep the ventilation section ratio within the range of 7%-12%, with an adjustable stroke of the moving grate of 70-120mm and a steplessly variable reciprocating frequency of 1-5 times/min, so that fuels of different qualities all burn reasonably fully.

The heat-resistant grate bars are produced on the Danish DISA casting line introduced by the company and keep stable performance even in a high-temperature combustion environment. Such grate bars help extend the service life of the equipment.