NOVELTY - The upper end of an air collecting tube (23) is connected to a space enclosed by a cylindrical inner air collecting cap (2) and a cylindrical middle air collecting cap (4). The lower end of the air collecting tube is connected to a hollow air storage kettle (22). A fuel gas outlet tube (25) equipped with a fuel gas valve (24) is connected to the top of the hollow air storage kettle and extends into the bottom of a gas stove (28). A separation blade (26) is set on the fuel gas outlet tube. A fireproof ceramic filter plate (27) is mounted on the upper layer of the gas stove.    USE - Rubbish burning furnace for producing fuel gas.    ADVANTAGE - Only blast fan is started when organic rubbish needs re-burning.    DETAILED DESCRIPTION - The cylindrical inner air collecting cap, cylindrical middle air collecting cap and cylindrical outer air collecting cap (5) are fixed at the upper part of the furnace housing (1) such that transparent arc gaps (3) are evenly distributed. The inner air collecting cap has a smaller diameter than the middle air collecting cap, is inserted in the upper part of the middle air collecting cap, and is connected to the middle air collecting cap by evenly distributed support sheets (6). The middle air collecting cap has a smaller diameter than the outer air collecting cap, is inserted in the upper part of the outer air collecting cap, and is connected to the outer air collecting cap by evenly distributed support sheets whose upper, lower, left and right parts are transparent. An insulating layer (7) is set on the circumference of the inner side of the lower part of the furnace housing. An ash outlet (10) with a cover (9) is set beside the bottom of the furnace housing at the center of which is disposed an electric furnace (12) on which a metal grate (13) is mounted at an interval. An upright thermal storage iron column (8) is mounted in the center of the furnace housing between the outer air collecting cap and the metal grate. An inner air tube is set in the center of the thermal storage iron column, and is vertically connected to air holes (11) evenly distributed on the outer cylindrical surface of the thermal storage iron column having a wall thickness not less than 1 centimeter and closed at the top end. A blast fan (17) mounted outside the furnace housing is connected to the lower end of the thermal storage iron column through a main air valve (18) and a main air tube (14) inserted in the furnace housing. An electric furnace air tube (15) is connected to the main air tube and is inserted in the furnace housing to be connected to the electric furnace. A discontinuously annular open outlet (C) is set on the circumference of the bottom of a circumferential drying interlayer (29) set on the periphery of the furnace housing. The hollow air storage kettle is mounted beside the furnace housing. An air inlet tube (16) is connected to the main air tube and passes through the furnace housing to be connected to the hollow air storage kettle through an air inlet valve (21). An exhaust tube with an exhaust valve (20) and a drain tube with a drain valve (19) are mounted on the lower part of the hollow air storage kettle.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the rubbish burning furnace.    Furnace housing (1)    Inner air collecting cap (2)    Arc gap (3)    Middle air collecting cap (4)    Outer air collecting cap (5)    Support sheet (6)    Insulating layer (7)    Thermal storage iron column (8)    Cover (9)    Ash outlet (10)    Air hole (11)    Electric furnace (12)    Metal grate (13)    Main air tube (14)    Electric furnace air tube (15)    Air inlet tube (16)    Blast fan (17)    Main air valve (18)    Drain valve (19)    Exhaust valve (20)    Air inlet valve (21)    Air storage kettle (22)    Air collecting tube (23)    Fuel gas valve (24)    Fuel gas outlet tube (25)    Separation blade (26)    Ceramic filter plate (27)    Gas stove (28)    Circumferential drying interlayer (29)    Open outlet (C)