US2757648A - Steam boilers - Google Patents

Description

A. TAMlLlN STEAM BOILERS Aug. 7, 1956 Filed Feb. 16, 1954 FIG.3'

IN VENTOR ATTORNEY United States PatentOflice M 2,757,648 Patented Aug 7, 1956 2,757,648 STEAM-BOILERS Andrew Tamilin, Erie, Pa., assignor-to Union Iron Works, Erie, Pat, a corporation otlennsylvania In steam boiler having; groups of; water wall tubes spaced from each other along alower header, poor water circulation has been obtained in those parts of the header between the groups of tubes. This invention is intended to improve the circulation by the use of an inner pipe within the lower header connected to the downcomers of each of the groups of tubes and conducting water laterally from the downcomers to the parts of the header between the groups of tubes.

In addition to improving the circulation, the cleaning of the header is easy because both the header and the inner pipe are free of obstructions blocking removal of sediment.

In the accompanying drawing, Fig. l is a front elevation of a steam boiler water wall having groups of tubes spaced apart from each other along a lower header, Fig. 2 is an end view, and Fig. 3 is an enlarged section on line 3-3 of Fig. 2 showing the lower header construction and water circulation.

The drawings show the lower part of the front Wall of a steam boiler. In the upper part of the wall there are tubes 1 uniformly spaced along a header 2. In the lower part of the wall in orderto provide openings 3 for firing by stokers 4 the water tubes are arranged in groups 5 spaced apart from each other and extending between the header 2 and a lower header 6. Each of the openings 3 for the stokers is between two of the groups 5 of tubes. The tubes in each of the groups 5 are shown as comprising a downcomer 7 and two upcomers 8. The parts so far described are or may be of common construction.

If the upcomers and downcomers 7 and 8 of each of the groups 5 of water tubes were directly connected to the lower header 6, the circulation of water in the lower header would be primarily confined to the immediate vicinity of the tubes and the water in the intermediate sections 9 of the lower header would be relatively stagnant. In order to provide the uniform circulation in the lower header 6 necessary for uniform heat absorption, the lower header 6 is made of an outer pipe 10 connected at its top to the lower ends of the upcomers 8 and an inner pipe 11 connected at its top to the downcomers 7. The connection between the upcomers 8 and the pipe 10 is made through sleeves 12. The downcomers 7 extend through sleeves 13 in the upper part of the pipe 10 and are connected by tubes or extensions 14 to sleeves 15 in the upper part of the inner pipe 11. The connections are conveniently made by welding. By this construction the water flowing down to the lower header 6 through the downcomers 7 is discharged directly into the inner pipe 11 and flows in opposite directions along the pipe from the downcomers as indicated by arrows 16. The water flows out of the inner pipe 11 primarily through openings 17 on the under side of the pipe midway between the groups 5 of water wall tubes. Small openings 17a directly above the openings 17 allow some flow directly to the space between the upper side of the pipe 11 and the adjacent surface of the pipe 10. This means that the water flowing downinto the lower header 6 will flow laterally along the. header to. a point intermediate to the groups of tubes before it can get outside the; inner pipe 11.

This insures lateral circulation from the downcomers 7 along the section of the lower header intermediate. the groups of tubes, After leaving the inner pipe 11, the water flows back toward the upcomers 8' along the space between the inner pipe 11 and the, outer pipe 10. Of course, at the extreme end'of the lower header 6 it is not necessary to have an opening, similar to the openings 17'. The ends, of the pipe 11 are open and the water from the downcomers adjacent the ends of the pipe 11' merely flows laterally out the end of the pipe and then upward through the upcomers 8:

The ends of the outer pipe 10 are closed by heads 18 provided with threaded plugs 19 through which the header may be inspected or cleaned. Since the inner pipe 11 is open at both ends there are no obstructions along the length of the header to restrict the removal of sediment. Also, the fact that the inner pipe 11 is open at both ends is desirable for inspection of the lower header.

What is claimed as new is:

1. In a steam boiler, a lower header comprising inner and outer pipes, a plurality of groups of water wall tubes spaced apart from each other and extending upward from the lower header, each of the groups having downcomer and upcomer tubes, connections between both the upcomer and downcomer tubes and the outer pipe of the lower header, the downcomer tube having extensions extending through the outer pipe to the inner pipe of the lower header, connections between the extensions of the downcomer tubes and the inner pipe of the lower header, and an opening in the inner pipe of the lower header leading to the space between the inner and outer pipes of the lower header, said opening being located between two adjacent groups of tubes whereby the water flowing down through one of the downcomers of one group of tubes flows laterally along the inner pipe of the lower header toward the adjacent group of tubes and then back through the space between the inner and outer pipes to the upcomers of said one group of tubes.

2. In a steam boiler, a lower header comprising inner and outer pipes, the outer pipe being closed at its ends by heads provided with clean-out openings and the inner pipe being open at its ends and terminating short of the heads, a plurality of groups of water wall tubes spaced apart from each other and extending upward from the lower header, each of the groups having downcomer and upcomer tubes, connections between both the upcomer and downcomer tubes and the outer pipe of the lower header, the downcomer tubes having extensions extending through the outer pipe to the inner pipe of the lower header, connections between the extensions of the downcomer tubes and the inner pipe of the lower header, and an opening in the inner pipe of the lower header leading to the space between the inner and outer pipes of thelower header, said opening being located between two adjacent groups of tubes whereby the water flowing down through one of the downcomers of one group of tubes flows laterally along the inner pipe of the lower header toward the adjacent group of tubes and then back through the space between the inner and outer pipes to the upcomers of said one group of tubes.

3. In a steam boiler, a lower header comprising inner and outer pipes, a plurality of groups of water wall tubes spaced apart from each other and extending upward from the lower header, each of the groups having downcomer and upcomer tubes, connections between the upcomer tubes and the outer pipe of the lowerheader, connections between the downcomer tubes and the inner pipe of the lower header, and said inner pipe having openings on the upper and under sides leading from the inner pipe to the space between the inner and outer pipes of the lower header, said openings being located between two adjacent groups of tubes whereby the water flowing down through one of the downcomers of one group to tubes flows laterally along the inner pipe of the lowerheader toward the adjacent group of tubes and then back through the space between the inner and outer pipes to the upcomers of said one group of tubes, and said openings in the inner pipe being of larger area on the under side of the inner pipe than on the upper side of the inner pipe.

4. In a steam boiler, 21 water wall having firing openings therein defined at the top and bottom by upper and lower headers and at the sides spaced groups of water wall tubes extending between the upper and lower headers, said lower header comprising inner and outer pipes, each of the groups having downcomer and upcomer tubes connected to the upper header, connections between both the upcomer and downcomer tubes and the outer pipe of the lower header, the downcomer tubes having extensions extending through the outer pipe to the inner pipe of the lower header, connections between the extensions of the downcomer tubes and the inner pipe of the lower header, and an opening in the inner pipe of the lower header leading to the space between the inner and outer pipes of the lower header, said opening being located between two adjacent groups of tubes whereby the water flowing down through one of the downcomers of one group of tubes flows laterally along the inner pipe of the lower header toward the adjacent group of tubes and then back through the space between the inner and outer pipes to the upcomers of said one group of tubes.

References Cited in the file of this patent UNITED STATES PATENTS 1,270,621 Kestner June 25, 1918 2,596,953 Evans et al. May 13, 1952 FOREIGN PATENTS 223,858 Great Britain Feb. 19, 1925

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