a hole 28 in a side wall of leg 14 to an end 30 positioned within the u configuration of the conduit 12 at an angle relative to the base 18 to direct a stream of air at the side wall of the base a second small tube 32 is mounted in the leg 16 and has an end 34 disposed at the corner where leg 16 joins base 18 the tube 32 extending through a hole 36 in a side wall of leg 16 to an end 38 within the u configuration of the conduit 12 at an angle relative to base 18 for directing a stream of air at the side wall of base 18 from a direction opposite to that of tubing 24 the tubes 24 and 32 form inwardly directly jets to deliver converging fresh air streams to the fuel and can be simply made from copper tubing one half inch in diameter for example a blower unit 40 includes an electrically driven fan 42 having an outlet 44 connected with a steel tubing or pipe elbow 46 and the elbow 46 has an end 48 adapted to be removably received in the inlet opening 20 of the conduit 12 and an end removably coupled with the.