JPS61204104U - - Google Patents

Description

[Brief explanation of drawings]

Figure 1 is a vertical sectional view of the boiler, Figure 2 is a sectional view of Figure 1, Figure 3 A is a side view of the main part of Figure 1, Figure 3 B is a sectional view of Figure 3 A, Figure 4 is a developed view of the combustion gas passage in Figure 1, Figure 5 is a vertical sectional view of a conventional boiler, Figure 6 is a sectional view of Figure 5, and Figure 7 is an expanded view of the combustion gas passage in Figure 5. It is a diagram. 1 is the upper header, 2 is the lower header, 3 is the water pipe,
4 is the gap, 5 is the boiler outer wall, 6 is the combustion gas passage,
7 is a flue, 8 is a fin, 9 is a slit, 10 is a combustion chamber, 11 is a combustion device, A is a combustion gas flow, and l is a horizontal plane.

Claims (1)

[Claims for Utility Model Registration] (1) Both the upper header 1 and the lower header 2 are formed in an annular shape, and the upper and lower headers 1 and 2 are connected by a large number of water pipes 3, and these water pipes 3 are formed in a very small number. It is arranged as an annular water tube wall with a gap 4, a boiler outer wall 5 is provided with a gap on the outside of the water tube wall, and an annular combustion gas passage 6 is formed between the water tube wall and the boiler outer wall. A flue 7 is provided on the outer wall of the boiler to communicate the combustion gas passage 6 and the flue 7, and a flat plate-shaped fin 8 is provided on the outer surface of the water pipe 3 facing the combustion gas passage in parallel to the combustion gas flow A. In a multi-tube once-through boiler in which water tubes are arranged in multiple stages in the axial direction, the distance S between the fins at both ends in the axial direction of the water tubes is defined as the position of the flue from the water tube on the side facing the flue with respect to the center line of the boiler. A heat transfer surface structure of a multi-tube once-through boiler characterized by a heat transfer surface that gradually decreases toward the water tube on the side where the water is heated. (2) The scope of the utility model registration claim, characterized in that the eight flat fins at both ends in the axial direction of the water pipe are arranged so as to be symmetrical to each other with respect to a horizontal plane l passing through the center of the flue 7. A heat transfer surface structure of the multi-tubular once-through boiler according to item 1. (3) Utility model registration claims 1 and 2, characterized in that the flat fin 8 is provided with an appropriate number of slits 9 so as to substantially intersect with the combustion gas flow direction A. Multi-tubular once-through boiler as described in Section 1.