A downward mobile gasification boiler for surface gas-phase combustion and pyrolysis of biomass briquette is provided. The boiler includes a gasification combustion chamber, a gas combustion chamber, a stranding cage slag remover, a heat exchanger, a water jacket, an air duct and an air distribution system. The air duct connected with the air distribution system is arranged in the inner cavity of the wall surface of the gasification combustion chamber. The gas combustion chamber is arranged at the upper part of the gasification combustion chamber, and an air outlet is arranged in the middle to communicate the gas combustion chamber with the gasification combustion chamber. The lower part of a port of the gasification combustion chamber is provided with a twisting cage slag remover.

Disclosed is a gas heater, including: a gas bottle for storing a gas, a valve body connector, and a burner. A cavity is provided in the valve body connector, both the regulator and the safety valve are communicated with the cavity, the regulator is connected to the gas bottle, the valve body connector is provided with a valve nozzle, and the valve nozzle is communicated with the cavity. An air inlet pipe is provided between the burner and the valve body connector, one end of the air inlet pipe is connected to the valve nozzle, another end of the air inlet pipe is connected to the burner. The gas enters the cavity of the valve body connector through the regulator, and enters the air inlet pipe through the valve nozzle.