BOILER HAVING SPIRAL HEAT TRANSFER TUBE

PROBLEM TO BE SOLVED: To provide a boiler having a spiral heat transfer tube which makes compatible both the prevention of the eccentricity of inner/outer coils, and the improvement of workability at assembling.SOLUTION: A boiler 1 having a spiral heat transfer tube has an inner coil 3 and an outer coil 4 being doubled-cylindrical heat transfer walls around which the heat transfer tube is spirally wound. A can body center portion surrounded by the double coils is made to serve as a combustion chamber 8, and a combustion gas which is generated in the combustion chamber 8 heats a thermal medium flowing in the heat transfer tube by passing through a combustion gas passage 7 which is formed between the inner coil and the outer coil. A spacer composed of a spacer first member 5 being a vertically-elongated member, and a spacer second member 6 being a member which is shorter than the spacer first member in a vertical direction is arranged in the combustion gas passage 7, the spacer first member 5 and the spacer second member 6 are thinner than a width of the combustion gas passage 7, and a prescribed interval can be secured between the inner coil 3 and the outer coil 4 by overlapping the spacer first member 5 and the spacer second member 6 on each other.SELECTED DRAWING: Figure 1 【課題】内外コイルの偏心防止と組立時の作業性向上を両立する螺旋状伝熱管を持ったボイラを提供する。【解決手段】伝熱管を螺旋状に巻回した二重の円筒形状伝熱管壁である内コイル３と外コイル４を持ち、二重のコイルで囲まれた缶体中心部分を燃焼室８とし、燃焼室８で発生した燃焼ガスは、内コイルと外コイルの間に設けている燃焼ガス通路７を通すことで、伝熱管内を流れる熱媒体を加熱するボイラ１において、前記燃焼ガス通路７内に、縦に長くした部材であるスペーサ第１部材５と、スペーサ第１部材より縦方向長さの短い部材であるスペーサ第２部材６からなるスペーサを設置するものであり、スペーサ第１部材５とスペーサ第２部材６はそれぞれ燃焼ガス通路７の幅より薄いものであって、スペーサ第１部材５とスペーサ第２部材６を重ね合わせることで内コイル３と外コイル４の間に所定の間隔を確保することを特徴とする螺旋状伝熱管を持ったボイラ。【選択図】図１