Latest Technology and Innovative Applications for Chain and Cross-beam Grates in Wafangdian
Chain grate
Combined combustion control system: Traditional chain-grate boilers use a single “grate-firing” method, but a new combined combustion control system for chain-grate boilers now merges grate firing with suspension firing. In this system, part of the coal from the feeding system is pulverized into ultra-fine coal powder by a coal mill and injected into the furnace chamber by a pulverized-coal burner to burn in suspension, while the rest of the coal is fed directly onto the boiler grate. An intelligent controller precisely manages the coal feed to both streams and regulates the exhaust-powder fan airflow based on the flame intensity inside the boiler. This combined firing approach raises the furnace temperature, slows the grate travel speed, and thins the coal bed, prolonging the burning time of the coal on the grate, increasing the ventilation coefficient of the coal bed, and reducing the carbon content of the ash. As a result, it boosts both the boiler output and thermal efficiency while meeting the requirements of energy conservation and environmental protection.
Tail-end waste-heat energy-saving and eco-friendly equipment: In some chain-grate hot-water boilers, tail-end waste-heat equipment such as waste-heat boilers, air preheaters, and dust-removal and desulfurization settling chambers has been added. The waste-heat boiler connects to the boiler body through the flue duct, increasing the heating surface area and water capacity, which can save 15%–20% of coal compared with conventional operation. The air preheater raises the temperature of the hot air entering the furnace, thereby increasing the furnace temperature, and its tubes are arranged in a vertical structure that resists ash accumulation. The dust-removal and desulfurization settling chamber allows solid particles such as flue dust to settle under gravity, while quicklime is added to react with the sulfur dioxide in the flue gas, achieving the environmental goals of dust removal and desulfurization. This equipment not only improves energy utilization but also effectively lowers both operating and maintenance costs.
New chain-grate structural design: A new type of chain grate, for example, adds components such as baffles, a heat-dissipation mechanism, a cleaning brush, and a dust-collecting funnel. The baffles prevent material from falling off the sides during grate operation and are easy to remove for replacement; the heat-dissipation mechanism blows air over the grate with a fan, effectively solving the grate’s heat-dissipation problem; the cleaning brush continuously cleans the ventilation holes of the grate to prevent dust from clogging them; and the dust-collecting funnel forms a sliding structure with the base through a chute, making it easy to remove the ash produced and improving the device’s practicality and maintenance efficiency.
