Improvements in Steam Boilers and the Flues in connection therewith.
Year: 1894

page_text: Date of Application, 17th Dec., 1894
Complete Specification Left, 2nd Apr., 1895-Accepted, 18th May, 18:5
PROVISIONAL SPECIFICATION
Improvements in Steam Boilers and the Flues in connection
therewith.
WILLIAM SMITH, Engineer, and WALTER GEORGE SMITH, Engineer, both
residing at Brookland, Sutton Leach, St. Helens, Lancashire do hereby declare the
nature of their invention for improvements in steam boilers and the flues in
connection therewith to be as follows:-
This invention relates to improvements in steam boilers and the flues in
connection therewith, & has for its object the prevention of the escape of the
heated gases from the back end of a boiler into the chimney flue, without first
having made a complete circulation of all the flues which the products of
combustion are intended to traverse.
When the products of combustion from the firegrates of a Lancashire, Galloway
or Cornish boiler have traversed along the internal flue or flues to the back end
of the boiler, they are directed into bottom or side flues for the purpose of again
traversing the full length of the boiler by one or more flues, returning by others
whereby the heated gases may pass along the full length of the boiler three times
before they are allowed to escape to the chimney.
Such a circulation can only be secured by the brickwork at the back end of the
boiler being at all times in close contact with the end of the boiler. Should there
be any space between the end of the boiler and the brickwork the hot gases or a
portion of them will on arriving the first time at the back end of the boiler pass
direct into the chimney flue without returning again by the brickwork fines to the
front end.
As all boilers are set on their seatings with a fall towards the front end, they
invariably creep by their continual expansions & contractions towards the lower
end of the seating, thus creeping away from the brickwork abutting against the
back end plate which thus fails to make a tight joint, whereby a portion of the hot
gases are permitted to pass from the Internal flue or flues of the boiler direct to the
chimney, the loss of fuel varying according to the width of the space between
the boiler & the brickwork.
Our invention consists in attaching to the end of the boiler a number of plates
or webs of metal which may either project into grooves or mortices in the back
seating walls, or lay as flanges along the surfaces of the seating walls, thereby
forming effectual break joint plates even when the boiler has withdrawn a
considerable distance from the seating walls at the back end, thus insuring the
circulation along the proper course of the flues of the whole of the hot gases
generated at the furnace fires.
Dated this 15th day of December 180A
WM. SMITH.
WALTER G. SMITH.

page_text: Improvements in Steam Bollers and the Flues in connection
therewith.
We, WILLIAM SMITH and WALTER GEORGE SMITH of Brookland, Sutton
Leach, St. Helens in the County of Lancaster, 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 steam boilers and the flues in
connection therewith, and has for its object the prevention of the escape of the
heated gases from the back end of a boiler into the chimney flue without first
having made a complete circulation of all the flues which the products of
combustion are intended to traverse. When the products of combustion from the
firegrates of a Lancashire, Galloway or Cornish boiler have traversed along
the internal flue or flues to the back end of the boiler, they are directed into
bottom or side flues for the purpose of again traversing the full length of the boiler
by one or more flues, returning by others, whereby the heated gases may pass along
the full length of the boiler three times before they are allowed to escape to the
chimney. Such a circulation can only be secured by the brickwork at the back end
of the boiler being at all times in close contact with the end of the boiler. Should there
be any space between the end of the boiler and the brickwork, the hot gases or a
portion of them will on arriving the first time at the back end of the boiler pass
direct into the chimney flue without returning again by the brickwork flues to the
front end. As all boilers are set on their seatings with a fall towards the front
eud they invariably creep by their continual expansions and contractions towards
the lower end of the seating, thus creeping away from the brickwork abutting
against the back end plate, which thus fails to make a tight joint, whereby a
portion of the hot gases are permitted to pass from the internal flue or flues of the
boiler direct to the chimney, the loss of fuel varying according to the width of the
space between the boiler and the brickwork.
Our invention consists in attaching to the end of the boiler a number of plates or
webs of metal which may either project into grooves or mortices in the back
seating walls or lie as flanges along the surfaces of the seating walls, thereby
forming effectual break joint plates even when the boiler has withdrawn a consider-
able distance from the seating walls at the back end, thus insuring the circulation,
along the proper course of the flues, of the whole of the hot gases generated at the
furnace fires.
In the drawings;
Figure 1 is a longitudinal section of the back portion of an ordinary Lancashire
boiler showing the brickwork flues by means of which the products of combustion
are made to return to the front end of the boiler, and also the main flue by which
they make their escape to the chimney;
Figure 2 is a sectional plan of the same;
Figure 3 is a cross section through the wings of the fender wall at the back end
of the boiler showing the bottom and side flues; and
Figures 4 and 5 are enlarged sectional plans of the back end of the boiler and
the wings of the fender wall showing two methods of forming the joint to prevent
the premature escape of the heated gases to the chimney.
The same letters of reference indicate the same parts in the several figures of the
drawing.
A, represents the boiler, B the internal flues through which the products of
combustion travel from the furnaces at the front to the back end as shown by the
arrows C. The whole of the hot gases should, on arriving at the back end of the

page_text: boiler, return by the bottom flue D to the front end of the boiler as shown by
the arrow E, there to split and finally to make their escape by the side flues F
through the dampers G to the chimney flue H.
When from any cause a clear space is left between the ends of the fender
wall JJ, and the back end plate of the boiler, a portion of the hot gases will be
drawn by the draught of the chimney through these openings, and through the
dampers to the chimney flue as shown by the arrows K K. The break joint plates
shown at Land M are designed to prevent this.
The break joint shown at L is formed by a piece of channel iron or by flanges
attached to the back end of the boiler, between which flanges, the ends of the fender
wall will be enclosed the full height of the side flues.
The break joint shown at M is formed by a tongue of metal attached to the
back end of the boiler, which fits into a groove in the end of the fender wall the
full height of the side flues.
When, for a Galloway or other type of boiler, the products of combustion are
designed to return from the back end to the front end of the boiler by the side
flues, and the bottom flue is in direct connection with the chimney flue, the break
joint plate should be fixed as shown at N, Figure 3. A break joint plate attached
to the boiler in the same manner as plate M, to prevent cold air being sucked into
the flues between the back end of the boiler and the covers P of the back flue, is
shown at O, Figures 1 and 3.
All the break joint plates are readily detachable in the event of caulking or
other repairs being required to the back end plate.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The improvement in steam boilers, which consists in projecting plates added
to their rear ends in such manner as to form with the brickwork or seating a
partition practically impervious to gases between the furnace flue and the chimney
at that point even when the boiler has crept somewhat.
2. The improvement in flues, which consists in an attachment to the boiler at the
rear end overlapping or interlocking with the division built up between the furnace
flue and the chimney, whereby if creeping take place there still remains a gas
tight joint.
3. The arrangement and construction of devices for preventing direct passage of
gases between the furnace flue and the chimney, without first traversing an
intermediate flue substantially as described and illustrated.
Dated this 1st day of Anvil 1805
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.