H-fin tube, also known as square-fin tube, is a strengthened heat exchange element arranged at the end of the flue of the system in order to recover smoke waste heat from power station boilers, industrial boilers, industrial kilns and Marine power plants and effectively improve the utilization rate of fuel. Because of the characteristics of convective heat transfer of low-temperature flue gas, that is, the heat release coefficient A1 of flue gas to the pipe wall is much smaller than the heat release coefficient A2 of the pipe wall to the soft water side, it is necessary to use the extended heating surface on the flue gas side. At present, the "economizer" (also known as economizer) used in the boiler has light tube type, spiral curved piece type, cast iron rib tube type, membrane wall tube type, etc., except light tube type, the rest are extended heating surface structure.

The disadvantages of welded steel spiral finned tube in practical application are mainly that the expansion surface area is restricted by the manufacturing process, the spiral sheet wound on the tube is difficult to remove ash, easy to cause ash accumulation, ash blocking phenomenon, and its flue gas side circulation resistance is high, so its application range is greatly affected by the fuel quality. Its advantages are high productivity, few manufacturing processes and high material utilization rate.

In the structural design of the square fin tube, a separate structure is adopted for the part of the tube that is prone to ash formation, which overcomes the disadvantages of spiral fin tube that is prone to ash accumulation, ash blocking and gas resistance, and is an improved product of spiral fin tube. In addition, the fin tube is cantilevered, under the action of pulse airflow, the fin vibration is more favorable for ash treatment.

H Finned tube (square finned tube) production technical requirements