Four-arch W flame two-stage dense and thin combustion device

The invention relates to the technical field of W flame staged combustion, in particular to a four-arch W flame two-stage dense and thin combustion device. A hearth of the device comprises an upper furnace body, a lower furnace body and a cold ash bucket, wherein the lower furnace body consists of a front upper furnace arch, a rear upper furnace arch, a front lower furnace arch, a rear lower furnace arch, a front wall and a rear wall bag. The four-arch W flame two-stage dense and thin combustion device has the beneficial effects that the ignition is stable, the space between the two sides of the jet flow of the two-stage combustor becomes large, the gas supplementing condition is good, the backflow of high-temperature flue gas is facilitated, the combustion is stable, and the heat load distribution is uniform; secondary air, dense coal powder and thin coal powder are subjected to layered injection and staged combustion after entering the hearth, so that the partial-stage concentrated community in the hearth i