Improvements in Flue Tubes for Steam Generators, said Improvements being also applicable for other purposes.
Year: 1892

page_text: Date of Application, 25th Oct., 1892
Complete Specification Left, 21st July, 1893-Accepted, 26th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Flue Tubes for Steam Generators, said
Improvements being also applicable for other purposes.
I, THOMAS KINLOCH BARCLAY of 15 Battlefield Avenue, Langside, Glasgow
in the County of Lanark, North Britain, Metal Merchant, do hereby declare the
nature of this invention to be as follows:-
This invention relates to improvements in flue tubes for steam generators said
improvements being also applicable for other purposes.
The object of my said invention as applied to steam generators is to economise
fuel and to extract a maximum of heat from the products of combustion as they
pass through the flue tube.
In the carrying out of my invention I provide each tube with a spiral strip of
inetal or other inaterial extending from end to end of the tube. As the products
of combustion are drawn through the tube they are caused to do so in a tortuous
manner following the convolutions of the spiral strip; in passing through the tube
in this manner, a large metallic surface is travelled over and thus a maximum of
the heat from the products of combustion is absorbed by the tube and by its
spiral strip, which heat is imparted to the water of the steam generator.
Any convenient number of spirals may be given to the strip, and the strip may
be of any suitable shape in cross section for example the edges of the strip which
are in contact with the tube may be wider in cross section than the centre of the
strip so as to give larger contact surface of the strip with the tube.
The strip is preferably of such a width that it can be readily inserted and
withdrawn and a special advantage of the spiral is that it can thus be readily cleaned
and it also acts as an efficient scraper or cleaner of the flue tube.
The spiral strip may if desired be hinged or jointed.
My said invention is also applicable for other purposes such as for the more
efficient absorption of cold in freezing machines.
In lieu of a single spiral formation of the strip I may employ a double or other
spiral, such as that formed from a strip of + formation in section.
Dated this 24th day of October 1892.
J. Y. JOHNSON,
115, St. Vincent Street, Glasgow, Petitioner's Agent.
COMPLETE SPECIFICATION.
Steam Generators, said
Improvements in Flue Tubes for
Improvements being also applicable for other purposes.
I, THOMAS KINLOCH BARCLAY of 15 Battlefield Avenue, Langside, Glasgow,
in the County of Lanark, North Britain, Metal Merchant, 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:-
This invention relates to improvements in flue tubes for steam generators such
as the flue tubes in multitubular boilers of marine, locomotive and like types.
The objects of my said invention are to economise fuel and to extract the
maximum of heat from the products of combustion as they pass through the flue
tubes, and in carrying out my said invention I employ deflectors or retarders
within the flue tubes. The said deflectors or retarders consist of lengths of helical
or twisted firebrick.
The firebrick resists the action of the fire gases and does not become oxydised
EQ17

page_text: or waste away readily. When the said helical or twisted firebricks are made from
fire clay, silica or other refractory substance, such as a mixture of fireclay and
asbestos, they absorb heat up to a certain point and thereafter radiate the heat in
such a manner as to prevent the deposition of soot, and also induce more complete
combustion. The said deflectors or retarders also act in a regenerative manner.
These deflectors or retarders can be used with forced, induced or natural draft.
In the case of locomotive flue tubes where these deflectors or retarders are used,
flue tubes of a larger diameter than usual may be used, the necessity of using
small tubes in order to retard the products of combustion in their passage to the
atmosphere, being avoided.
Figure 1 represents a short length of the spiral fireclay deflector or retarder;
Figure 2 being an end view of same.
Figure 3 represents the spiral provided with a central boss a through which runs
a rod, having a nut at the one end and an eye at the other; the eye is used for
drawing the spiral out of the tube for cleaning purposes. Also the rod
can be
utilised for joining together any desired number of deflectors or retarders; the
eye may be used for connecting them together.
Figure 4 is an end view.
Figure 5 is a triple blade spiral; Figure 6 being an end view of same.
Figure 7 is a similar spiral provided with a boss similar to that shown in
Figure 3 with rod for the same purpose as before described.
Figure 9 is a section of a boiler flue tube showing the firebrick deflector or
retarder in position. The said spiral can be of any length desired.
Any convenient number of blades may be given to the spirals; and they may be
of any suitable shape in cross section.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
In the flue tubes of steam generators the employment of firebrick deflectors or
retarders substantially as and for the purposes hereinbefore described and shown
in the accompanying drawings.
Datad this 20th day of Iul 1902