How a 300-person team solved the technical challenges of reciprocating grates

Reciprocating grates have many advantages, but the industry also sees pain points: poor working conditions for grate bars in the high-temperature zone, fairly serious coal leakage and poor adaptability to load changes. Our partner factory set up a 300-person professional R&D team, and after years of technical work the team has solved these problems one by one, driving continuous upgrading of reciprocating grate technology.

Material and structural improvements for high-temperature grate bars

Targeting the core pain point that grate bars in the high-temperature zone are easily damaged, the R&D team worked on both material and structure. On the material side, working with universities, it developed a dedicated heat-resistant alloy that raised the heat resistance of the bars from 800℃ to 1100℃, and it improved wear resistance through microstructure optimisation. After the microstructure optimisation, bar service life is more than 2 times longer.

On the structure side, it designed a hollow cooled grate bar with internal cooling air ducts, where the air flow carries heat away and lowers the working temperature of the bar. This technology has been granted 3 national utility model patents.

Coal-leakage control and load adaptability

To solve coal leakage, the team optimised the lap structure of the bars with a stepped overlapping design, narrowing the gap between bars from the traditional 3-5mm to 1-2mm. An adjustable coal-leakage recovery device was also added under the grate, bringing the leakage rate from above 5% down to below 1%.

For poor adaptability to load changes, the team developed an intelligent variable-frequency control system that monitors furnace temperature, pressure and other parameters in real time through sensors. The system then adjusts grate movement speed and air supply automatically, giving smooth load regulation in the 30%-110% range.

These improvements cover the three areas of material, structure and control. The performance of the partner factory’s reciprocating grates in high-temperature bar life, coal leakage rate and load adaptability improved accordingly.