Improvements in Multitubular Flues for Steam Boilers.
Year: 1890

page_text: Date of Application, 29th Apr., 1890-Accepted, 31st May, 1890
COMPLETE SPECIFICATION.
Improvements in Multitubular Flues for Steam Boilers.
I, WILLIAM COOK of Salt Lake City, Salt Lake County in the Territory of Utah,
United States of America, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :—
My invention relates to an improved construction of the kind of boilers employed
for locomotive and other portable steam engines, in which the heated products of
combustion are conveyed from fire chamber to smoke stack through numerous small
tubes. Among useful results believed to accrue from said invention is facility of
construction and of removal; inspection and substitution of flue-tubes; and better
bracing and avoidance of strain of the tube-sheets, thus enabling a greator
steam-pressure with even greater safety.
Referring to the accompanying drawings which form a part of the specification:
Fig. 1 is a partially sectioned side elevation of a boiler embodying my invention.
Fig. 2 shows portions of a flue-tube to full size, the ferrule being partly in
section.
Fig. 3 is a section on line 3-3.
1 may represent the fire-chamber; 2 tube-sheet of same; 3 water and steam
space; 4 box or receiving chamber of smoke-stack 5; 6 represents tube-sheet of
said smoke-box.
The flue-tubes 7 have the customary lip or flare 8 at their receiving ends to engage
around the margin of the flue-holes in the tube sheet 2.
The delivery ends of said tubes extend somewhat through the tube-sheets and aro
screw-threaded exteriorly, as at 9, for an interiorly threaded ferrule 10, preferably of
brass or other non-corrodable metal.
Orifices 11 in said ferrule serve as passages for oil to the threaded surfaces, to
facilitate the unscrewing of the ferrule from a tube which it may be desired to
remove, or the tightening or slackening of a ferrule where found necessary.
The junctions of the flue with the tube sheets are made steam-tight by the following
means:
A groove (see dotted lines S¹) on the inside of the lip 8 forms an annular chamber
for any suitably soft and refractory packing, such as a copper or asbestos gasket at
the junction of the flues with the tube-sheet 2. A like annular chamber 10' in the
ferrule is provided for a similar gasket or packing at the junction of the flues with
the tube-sheet 6.
The tubes may be plated with tin, copper or any other metal or material desired to
prevent rust.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A flue-tube of a steam boiler whose delivery end extends beyond the flue
sheet said extension being exteriorly screw-threaded, in combination with an
interiorly screw-threaded ferrule, as and for the purpose set forth.
2. A flue-tube of a steam boiler whose delivery end extends beyond the flue-
sheet, said extension being exteriorly screw-threaded, in combination with an interiorly
screw-threaded ferrule, having oil-ducts or passages, as and for the purposes set forth.
3. A flue-tube of a steam boiler whose receiving end has a retaining lip formed
with an annular chamber 8 for a packing gasket at the junction of the receiving
ΓΟ
7

page_text: end of the flue with the tube-sheet 2 and whose delivery end extends beyond the
Hue-sheet for a screw-threaded retaining ferrule formed with an annular
chamber 10 for a packing gasket at the junction of the flue with the
tube-sheet 6.
Dated this 14th day of April 1890
·
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.