IMPROVEMENTS IN STEAM GENERATORS
Year: 1869

page_text: LETTERS PATENT to Charles Mathew Barker, of 12, Kennington
Park Road, in the County of Surrey, Engineer, for the Invention
of "IMPROVEMENTS IN STEAM GENERATORS."
Sealed the 19th October 1869, and dated the 21st April 1869.
PROVISIONAL SPECIFICATION left by the said Charles Mathew
Barker at the Office of the Commissioners of Patents, with his
Petition, on the 21st April 1869.
I, CHARLES MATHEW BARKER, of 12, Kennington Park Road, in the
County of Surrey, Engineer, do hereby declare the nature of my said
Invention for "IMPROVEMENTS IN STEAM GENERATORS," to be as follows:-
This Invention relates to vertical tubular steam generators or boilers,
and has for its object the increasing the heating surface which is in all
cases according to this Invention situate below the ordinary water line,
and the increasing the durability of the boiler by preventing the undue
strains on the tube plates hitherto arising from the expansion and con-
traction of the tubes; facility is also afforded for readily removing the
outer shell of the boiler for cleaning or repairs.

page_text: According to this Invention the boiler is constructed with an inner
and outer shell connected together by an annular base plate. The inner
shell, which is rivetted to the annular base plate, forms the fire-box; the
space between it and the exterior shell which is bolted to the said base
plate contains the water and return descending flue tubes herein-after
described. The bolting of the exterior shell to the base plate is effected
by means of ordinary bolts and nuts in combination with strengthening
or washer plates of a length sufficient to receive three or more of the
bolts. Between the junction surfaces of the shell and the annular base
plate a seating of sheet lead inclosed in or lapped with copper wire
gauze is interposed, the gauze preventing the lead from being pressed
out under the pressure of steam or of the bolts. The washer plates
equalise the strain on the flange of the outer shell and on the lead and
copper gauze seating. Near the under surface of the fire-box (the top or
roof of which is considerably below the water level) are disposed in one
or more circular series a number of water circulating tubes, which are
secured by expanding them at their upper ends into tube spaces in the
roof plate of the fire-box, whilst their lower ends are curved upwards
and secured by being expanded into tube spaces in the annular base
plate before referred to, so as to communicate with the annular water
space of the boiler. Round the exterior of the fire-box or internal shell,
and within the said annular water space, are disposed a number of
descending return curved tubular flues, the upper ends of which are
secured by being expanded into tube spaces in the roof plate of the
internal shell or fire-box, whilst their lower ends are expanded into the
annular base plate before referred to, and communicate with an annular
chamber situate beneath the said base plate and opening into the main
flue. The lower parts of the water tubes are protected from the direct
action of the incandescent fuel by an annular shield or by a series of
tube protectors. The fire hole is made by a screwed tube and screw
flanges, the tube serving to connect the two shells, as the flanges are
bolted or otherwise secured to suitable flat surfaces on each shell. The
joints are made by the aid of lead and wire gauze, as herein-before
.described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Mathew Barker in the Great Seal Patent
Office on the 21st October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
MATHEW BARKER, of 12, Kennington Park Road, in the County of
Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Twenty-first day of April, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Charles Mathew Barker, Her special
license that I, the said Charles Mathew Barker, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Mathew
Barker, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and at all times thereafter.
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN STEAM GENERATORS,' upon the condition (amongst
others) that I, the said Charles Mathew Barker, my executors or
administrators, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said In-
vention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
"
NOW KNOW YE, that I, the said Charles Mathew Barker, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say :-
My said Invention relates to vertical tubular steam generators or
boilers, and has for its object the increasing the heating surface, which
is in all cases according to this Invention situate below the ordinary
water line, and the increasing the durability of the boiler by preventing
the undue strains on the tube plates hitherto arising from the expansion

page_text: and contraction of the tubes; facility is also afforded for readily removing
the outer shell of the boiler for cleaning or repairs.
According to this Invention the boiler is constructed with an inner
and outer shell connected together by an annular base plate. The inner
shell, which is rivetted to the annular base plate, forms the fire-box; the
space between it and the exterior shell, which is bolted to the said base
plate, contains the water and return descending flue tubes, herein-after
described. The bolting of the exterior shell to the base plate is effected
by means of ordinary bolts and nuts in combination with strengthening
or washer plates of a length sufficient to receive three or more of the
bolts. Between the junction surfaces of the shell and the annular base
plate a seating of sheet lead enclosed in or lapped with copper wire
gauze is interposed, the gauze preventing the lead from being pressed
out under the pressure of steam or of the bolts. The washer plates
equalize the strain on the flange of the outer shell and on the lead and
copper gauze seating. Near the inner surface of the fire-box (the top or
roof of which is considerably below the water level) are disposed in one
or more circular series a number of water circulating tubes, which are
secured by expanding them at their upper ends into tube spaces in the
roof plate of the fire-box, whilst their lower ends are curved upwards and
secured by being expanded into tube spaces in the annular base plate
before referred to so as to communicate with the annular water space of
the boiler. Round the exterior of the fire-box or internal shell and
within the said annular water space are disposed, according to one
arrangement, a number of descending return curved tubular flues, the
upper ends of which are secured by being expanded into tube spaces in
the roof plate of the internal shell or fire-box, whilst their lower ends
are expanded into the annular base plate before referred to, and com-
municate with an annular chamber situate beneath the said base plate
and opening into the main flue; or these tubes may be dispensed with,
and a central flue opening from the crown of the fire box and passing
out laterally through the outer shell may be employed, such flue being
kept entirely below the water level; or the descending fire tubes and the
central flue last described may be combined together, the central flue
being used to obtain increased draught when first lighting the fire,
after which it may be closed by a damper, and the descending fire tubes
alone employed for conveying away the products of combustion to a
chimney outside the outer shell. The lower parts of the water tubes

page_text: may be protected from the direct action of the incandescent fuel by an
annular shield, or by a series of tube protectors. The fire hole is made
by an internal and externally flanged tube serving to connect the two
shells, the flanges being bolted or otherwise secured to suitable flat
surfaces formed by rings rivetted on to each shell. The joints at these
parts are made by the aid of lead and wire gauze, as herein-before
described.
And in order that my said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings; the same letters of reference indicating corresponding parts
in all the Figures,
Figure 1 of my Drawings represents an elevation, partly in section, of
one arrangement of my improved vertical boiler; and Figure 2 is a
horizontal section of the same taken just above the fire-box.
A is the inner shell or fire-box, and B the outer shell; the inner shell is
rivetted to the annular base plate C, whilst the outer shell is simply bolted
thereto for the facility of removal for cleaning or repairs; D, D, are a
series of strengthening or washer plates of a length sufficient to receive
three or more of the bolts. Between the junction surface of the outer
shell and the annular base plate a seating of sheet lead inclosed in or
lapped with copper wire gauze is interposed, as and for the purpose herein-
before referred to. Near to and surrounding the inner surface of the
fire-box are disposed in one or more circular series a number of tapered
water circulating tubes E, E, expanded at their upper ends into the
crown or roof of the fire-box, whilst their lower ends are carried past
the inner edge of the annular base plate C, and are bent or turned up
and expanded into such plate, so as to open into the bottom of the
annular water space F which intervenes between the inner and outer
shells. G, G, are a number of descending return flues tubes, which are
curved downwards at their upper ends, and are expanded into the crown
plate of the fire-box; these tubes pass vertically downwards through
the annular water space F, and are expanded at their lower ends into
the annular base plate C, where they communicate with an annular
chamber H, which surrounds the ash-pit, and opens by an outlet I
into the chimney or main flue K situate just outside the outer shell B,
and provided with a damper L for regulating the draught. The con-
struction of the fire hole will be clearly understood from the description

page_text: herein-after given of the remaining Figures. M is the fire-door; N, the
steam dome; O, the steam pipe, and P, the fire-grate. This grate is
composed of three castings supported on cross bearers Q, which rest
upon the ledge or surface of the annular plate C between the water
tubes E, as shown clearly in Figure 2. R, R, represent foundation
plates, herein-after more fully referred to, for supporting the boiler,
which is secured thereto by screws at S, S.
Figure 3 represents a sectional elevation, and Figure 4 a sectional
plan taken along the water line of a modified arrangement, wherein the
descending flue or fire tubes G are dispensed with, and a central flue T
is employed bolted to the centre of the crown or roof plate of the fire-
box. This flue T is entirely below the water level, and branches off
laterally to the chimney K, a regulating damper L being employed for
controlling the draught. The outer end of the flue T is formed with a
flange, which is bolted to an internal flange on an annular junction
piece V. This junction piece is bolted to a ring W, which is rivetted
with countersunk rivets to the exterior of the outer shell in order to
form a flat surface for the bolting thereto of the outer flange of the
junction piece, which serves to connect the chimney K with the flue T.
The fire hole is composed of a short tube X provided with internal and
external flanges at its inner and outer extremities respectively. These
flanges are respectively bolted to rings Y, Y', rivetted to the inner and
outer shells for the purpose of presenting flat junction surfaces, against
which the flanges of the tube X are bolted. The joints between the
outer end of the flue T and the junction piece V, and between the
rings Y, Y', and the flanged ends of the tube X forming the fire hole,
are made tight by the interposition of lead and wire gauze, as already
described. R, R, are the foundation plates resting on brickwork Z, and
supporting the entire weight of the boiler. I prefer to use four of these
plates, although two may in some cases be sufficient, the screws S, S,
without nuts serving to secure the boiler down to the plates R. Holes
or recesses are made in the foundation plates for the reception of the
heads of the bolts which secure the outer shell to the annular base
plate C at those parts where they would otherwise interfere with the
foundation plates.
Figure 5 represents a sectional elevation, and Figure 6 a sectional
plan taken along the water line of a third modification, wherein both
the central flue T and the descending return tubes G, G, are combined.

page_text: By this combination facility is afforded for getting up a powerful
draught when first lighting the fire by opening the damper L of the
flue T, and using such flue in addition to the down draught flue
tubes G, G, after which the damper L may be closed, and the whole
of the draught be conducted through the descending flue tubes only.
The flue T communicates directly, as in Figures 3 and 4, with the
chimney K, but the annular chamber H into which the descending
flue tubes G open communicates by two outlets I with two vertical
flue tubes a, a, opening into each side of the main chimney K at its
lower end, as shown clearly in Figures 5 and 6. By using the expanded
water tubes E arranged as herein-before described and illustrated by
my Drawings, I obtain a constant supply of water to replace the liberated
steam, whilst the deposition of sediment within the tubes is prevented,
owing to the constant upward circulation of the water therethrough.
Moreover the curves in the ends of the water tubes and descending flue
tubes respectively allow for free expansion and contraction of the tubes
without prejudicially affecting the joints and plates in which the said
tubes are expanded, and consequently the injurious strain upon the
boiler plates arising from the continual expansion and contraction of
the tubes is prevented.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be
used or carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention
secured to me by the hercin-before in part recited Letters Patent is,―
First. The constructing of vertical steam generators wherein the whole
of the heating surfaces are situate below the level of the water in the
boiler, substantially as herein-before described.
Second. The constructing of vertical steam generators with curved.
ascending water tubes disposed round the interior of the fire-box, and
opening into the bottom of the annular water space between the inner
and outer shells of the boiler, substantially as herein-before described.
Third. The constructing of vertical steam generators with curved
return descending flue tubes connected with the upper part or crown
plate of the firc-box, and passing through the annular water space round
the fire-box into an annular chamber surrounding the ash-pit, sub-
stantially as herein-before described.

page_text: Fourth. The combination of the curved ascending water tubes, the
curved descending flue or fire tubes, and the annular chamber com-
municating with a chimney, all arranged and operating together sub-
stantially as herein-before described.
In witness whereof, I, the said Charles Mathew Barker, have to 5
this my Specification set my hand and seal, the Twenty-first
day of October One thousand eight hundred and sixty-nine.
CHA. M. BARKER. (L.S.)