Powdery fuel preheating gas generator and corresponding powdery fuel boiler

The invention relates to a powdery fuel preheating gas generator and a corresponding powdery fuel boiler. An existing pulverized coal preheating burner and a corresponding boiler are small in operation elastic space, so that the pulverized fuel preheating gas generator comprises a preheating combustion chamber, a gas-solid separator and a return feeder, and further comprises an auxiliary gas-solidseparator which is arranged in the middle section of a gas outlet pipe connected with a gas outlet in the top of the gas-solid separator. The auxiliary gas-solid separator comprises an expanded shell, the area of the cross section of an inner cavity of the expanded shell is larger than or equal to 1.3 times that of the cross section of the gas outlet pipe, and the height of the expanded shell islarger than or equal to 0.5 m. And a gas-solid pre-separation chamber can be additionally arranged at the upper part of the preheating combustion chamber. The powdery fuel horizontal boiler comprisesa horizontal boiler body an