Patent ID: 7281478

Claim:
A plasma ignition device for directly igniting a pulverized coal boiler, comprising a plasma generator, a pulverized coal burner, and a dc power supply for supplying electric power to the plasma generator, wherein said plasma generator comprises a cathode, an anode, an electromagnetic coil disposed around a space between the cathode and the anode when the cathode is moved away from the anode, and a linear motor for driving the cathode back and forth to contact the anode or move away from the anode, and wherein said pulverized coal burner comprises an external cylinder, at least two stages of burning chambers arranged in the external cylinder and cascaded one after another, inlet tubes respectively for said at least two stages of burning chambers, a primary air-pulverized coal tube for supplying an air-pulverized coal mixture of air and pulverized coal to said inlet tubes of said at least two stages of burning chambers, an auxiliary air inlet tube for supplying auxiliary air into the external cylinder, and a burner nozzle in an end of a last stage burning chamber, wherein the plasma generated by an arc discharging between the cathode and the anode will ignite the air-pulverized coal mixture in a first stage burning chamber, which further ignites the air-pulverized coal mixture in the next stage burning chamber, and wherein the auxiliary air or air-pulverized coal mixture flowing between walls of the respective stages of the burning chambers or between the external cylinder and outside walls of the respective stages of the burning chambers cools the walls of the respective stages of the burning chambers.