US1789799A - Water-tube boiler - Google Patents

Description

Jan. 20, 1931. H. E. YARROW WATER TUBE BOILER Filed Sept. 19. 1927 2 Shoots-Sheet 1 java Zar r0 7a" 715' garr'ow 1 Patented Jan. 20, 1931 UNITED STATES HAROLD EDGAR YARROW, 0F. GLASGOW, SCOTLAND WATER-TUBEVBOILER Application filed September 19, 1927, Serial No. 220,442, and in Great Britain November 18, 1926.

In order to protect the casing of the com bustion chambers of water tube boilers from excessive heat, ithas been proposed entirely to close the four sides of the chamber by the generating tubes, and for this purpose auxiliary drums have been provided parallel and adjacent to the lower side walls, from which drums tubes extend to an upper steam and water drum.

According to the invention, one or more sets of these auxiliary tubes forms at each side wall a single bank of tubes at the auxiliary drums and a bank of tubes of two or more rows in depth at their upper ends where they enter the steam and water drum. 7

For this purpose the auxiliary tubes con necting the auxiliary drums with the steam and water drum are arranged in groups which are relatively displaced in relation to the axes of the auxiliary drums, and are arranged fan-wise, converging from each aux iliary drum towards the steam drum, so that, while the tubes at their lower ends form a single row, the tubes of adjacent groups overlap towards their upper ends to form a double or multiple row.

In the accompanying drawings which represent an arrangement of auxiliary drums and water tubes according to the invention-- Fig. 1 is a vertical section of a Yarrow type boiler embodying this arrangement, v

Fig. 2 a partial sectional plan on line 2-2 of Fig. 1, and

Fig. 3 a transverse section on line 33 of Fig. 1 of one example. i

In these figures, A is the steam and water drum and B, B the water drums of a Yarrow type of water tube boiler. C and C are additional. drums extending at right angles to the drums B, B and forming the base of the triangular. disposition of the con'ibustion chamber as viewed from either side.

Straight tubes D extending from the drums C, C to the upper drum A are uniformly spaced along the length of the drums C, C" and spread in a fan-like disposition outwards from the upper drum where they are located in the lower portion of the upper drum in line with the main generating tubes of the boiler.

The tubes D are arranged in groups E to E, which are relatively displaced with reference to the longitudinal axes of the drums C, C As shown in Fig. 2, theouter section E of tubes on the left hand side is displaced to one side of the axis, the nextrsection E is on the axis, the middle section (which is a double section having twice the number of tubes) is on the opposite side of the axis and the sections E and E are disposed, re spectively, in the same manner as E and E.

As will be seen from the drawings, the tubes in each section or group are parallel with each other, but the several groups are arranged fan-wise, converging from the auxiliary drums C, C towards the steam drum A.

This arrangement has the advantage that at the base of the triangle, where the furnace is cooler, the tubes are disposed, preferably, in a single row, but they concentrate at the upper portion of the furnace where the heat is more intense to enter the upper drum in parallel longitudinal rows forming a bank of tubes, two, three or more rows in depth.

Downflow tubes F may be provided at each end of the tubes C, C".

The arrangement according to the invention not only protects the side walls of the combustion chamber against excessive heat but forms an extension of the space availabl for the gene 'ation of steam.

Tl10 application of the invention is not restricted to the three drum type of boiler.

illustrated.

Although in the example illustrated there is only a single set of auxiliary tubes at the auxiliary drun'is, two or more such sets may be provided.

l-laving thus described the nature of the said invention and the best means I know of carrying the same into practical effect. I claim i I 1. In a water tube boiler, an elevated steam and water drum, water drums parallel therewith, inclined banks of water tubes connect in g said water drums with-the elevated steam drum, transversely disposed auxiliary water drums arranged parallel and adjacentto the lower parts of the side walls of the furnace, and water tubes connecting said auxiliary drums with said elevated steam and Water drum, said Water tubes consisting of straight tubes arranged in groups, said groups being arranged fanivise and converging from each auxiliary Water drum towards the elevated steam drum and the tubes of each group being parallel with each other but inclined with respect to the tubes of adjacent groups.

2.91 Water tube boiler according to claim 1, wherein the tubes of each of the several groups form at their lower ends a single row and such rows are relatively staggered.

In testimony whereof I have signed my name to this specification.

HAROLD EDGAR YARROV.

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