IMPROVEMENTS IN STEAM BOILERS
Year: 1883

page_text: LETTERS PATENT to George Coleman Fraser and John Hazell Fraser both of
Bromley-by-Bow in the County of Middlesex Engineers for an Invention
of "IMPROVEMENTS IN STEAM BOILERS
ני
PROVISIONAL SPECIFICATION left by the said George Coleman Fraser and
John Hazell Fraser at the Office of tho Commissioners of Patents on the
25th June 1883.
GEORGE COLEMAN FRASER and JOHN HAZELL FRASER both of Bromley-by-Bow
in the County of Middlesex Engineers "IMPROVEMENTS IN STEAM BOILERS"
Our Invention relates principally to that class of upright cylindrical tubular
steain boilers in which the tubes in lieu of occupying the water and steam space
above the crown of the firebox hang down from the crown plate into the firebox
as with "Field" or analogous tubes-Under this arrangement the firegrate being
below the tubes the bottoins of the latter become injuriously choked with incrus-
tation-difficulty is also experienced in firing and removing the clinkers and
in distributing the fuel uniformly over the firegrato
Now our invention has for its object to remedy these defects and at the same
time increase the heating surface and power of such boilers-It consists in the
combination and use with an upright tubular boiler of a horizontal cylindrical
firebox (or flue) and outer shell or casing of any desired diameter and length
arranged on the Cornish principle that is to say-the firebox (or flue) of the
Cornish portion of our compound boiler is secured to the firebox of the upright
portion and communicates therewith-The shell or casing of the Cornish portion
is also secured to that of the upright portion of the boiler the water spaces of the
two portions communicating with each other-The outer shell or casing of the
Cornish portion may be either parallel in diameter throughout or enlarged at its
end of attachment to the upright portion for allowing a free escape of the steam as
generated-If desired a steamn space may be formed in the Cornish portion and
communicate with the steam space of the upright portion
The firebars and bridge aro arranged within the firebox (or flue) of the Cornish

page_text: portion in the usual manner and the outlets for the gases of combustion are
arranged so as to ensure a proper distribution of the heat between the tubes and
pass from the firebox of the upright portion through the water space and shell or
casing into suitable flues communicating with the chimney
By this invention the use of the Cornish portion adds greatly to the heating
surface and power of the boiler and the gases of combustion being compelled to
pass thoroughly amongst and impinge upon the hanging tubes a larger portion of
the surface of the latter is acted upon than is the case with an upright boiler
alone The stoking is also rendered easier and the distribution of fuel on the fire-
bars more uniformly and economically effected
If desired we may use baffle plates or screens in combination with the tubes for
directing the gases of combustion as required
Our invention may be applied to every description of upright boiler tubular or
otherwise

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Coleman Fraser and John Hazell Fraser in the Great Seal
Patent Office on the 22nd December 1883.
GEORGE COLEMAN FRASER and JOHN HAZELL. FRASER both of Bromley-by-Bow
in the County of Middlesex Engineers "IMPROVEMENTS IN STEAM BOILERS'
"
Our Invention relates principally to that class of upright cylindrical tubular
steam boilers in which the tubes in lieu of occupying the water and steam space
above the crown of the firebox hang down from the crown plate into the firebox
as with "Field"
or analogous tubes-Under this arrangement the firegrate being
below the tubes the bottoms of the latter become injuriously choked with incrus-
tation-Difficulty is also experienced in firing and removing the clinkers and in
distributing the fuel uniformly over the firegrate
Now our invention has for its object to remedy theso defects and at the same
time increase the heating surface and power of such boilers-It consists in the
combination and use with an upright tubular boiler of a horizontal cylindrical
firebox (or flue) and outer shell or casing of any desired diameter and length
arranged on the "Cornish" principle that is to say the firebox (or flue) of the
Cornish portion of our compound boiler is secured to the firebox of the upright
portion and cominunicates therewith-The shell or casing of the Cornish portion is
also secured to that of the upright portion of the boiler the water spaces of the two
portions communicating with each other
And in order that our said invention may be well understood we shall now
proceed particularly to describe the same reference being made to the accompanying
sheet of drawings whereon like letters of reference indicate corresponding parts in
all the figures
Figure 1 is a front elevation of a boiler constructed and arranged according to
our invention-figure 2. a sectional elevation on line. 1. 2. in figure 1 and figure 3
a half sectional plan on line 3. 4. in figure 2.
A represents an upright boiler fitted with "Field " or analogous tubes B which
hang down from the crown plate of the firebox C into the latter, the firegrate
usually found below the tubes B being in this case dispensed with-Attached to
the firebox C and communicating therewith is a horizontal cylindrical firebox (or
flue) D. of any desired diameter and length arranged on the Cornish boiler
principle and surrounded by an outer shell or casing E. which is secured to the
outer shell or casing F. of the upright boiler A. the water spaces of the two
combined portions A and D. communicating with each other
The outer shell or casing E. of the Cornish portion D is tapered or enlarged at
its end of attachment to the outer shell or casing F. of the upright boiler A for
allowing a free escape of the steam generated in the Cornish portion D.-Or the
outer shell or casing E. may be of parallel diameter throughout as found most
suitable
If desired a steam space may be formed in the Cornish portion D and commu-
nicate with the steam space of the upright boiler A
The firebars G are arranged within the firebox or flue D of the Cornish portion
of the compound boiler in the usual manner with Cornish boilers and in order to
ensure a proper distribution of heat between or amongst the tubes B. the outlets H
for the escape of the gases of combustion are arranged radially (or otherwise) on
that side of the firebox C. of the upright boiler A furthest from or opp site to the
inner end of the horizontal cylindrical firebox D of the Cornish portion and thence
pass through the water space of the upright boiler A. and through its outer shell or

page_text: casing F. into suitable flues I. which after passing round and about the combined
upright and horizontal or Cornish portions A. and D. of the boiler communicate
with the chimney-Or if desired the brickwork may be dispensed with and an
ordinary uptake substituted
By this invention the use of the Cornish portion D. adds greatly to the power of
the boiler and the gases of combustion being compelled to pass thoroughly amongst
and impinge upon the hanging tubes B. a larger portion of the surface of the latter
is acted upon than is the case with an upright boiler alone.-The stoking and
clinkering are also rendered easier and the distribution of fuel on the firebars more
uniformly and economically effected
-
If desired we may use baffle plates or screens in combination with the tubes B.
for more perfectly directing the gases of combustion as required.
Amongst the advantages of our invention which may be applied to every
description of upright boiler tubular or otherwise are. (1) Grent economy of fuel
the heating surface per horse power being double that obtainable in the ordinary
form of upright boiler (2) The circulation of water being greater less incrustation
is formed and by the increased steam space priming is checked (3) As the flames
and gases of combustion strike the sides of the tubes B., and not the bottom as in
ordinary upright boilers, incrustation or deposit will not injure the tubes
Having now described and particularly ascertained the nature of our said
invention and the manner in which the same is or may be used or carried into
effect we would observe in conclusion that what we consider novel and original and
therefore claim as the invention secured to us by the hereinbefore in part recited
Letters Patent is :-
66
-
The combination and use with an upright boiler (tubular or otherwise) of a
horizontal or Cornish" portion; constructed and arranged substantially as and
for the purposes herein before described and illustrated by the accompanying
drawing
-
-
In witness whereof we the said George Coleman Fraser and John Hazell
Fraser have hereunto set our hands and seals this Fourteenth day of December
in the year of Our Lord One thousand eight hundred and eighty three.
GE
FRASER (L.S.)
Witness to the signature of Geo. C Fraser,
FREDERICK BIRKS, Comm¹. Clerk,
30, Caxton St. Bow, London, E.
Witness to the signature of Jno H Fraser
EDWARD W FURRELL Mem Inst. M.E.
Patent Agent
Bank Bldgs.
124 Chancery Lane
W.C.
JNº. H. FRASER (L.S.)