IMPROVE- MENTS IN STEAM BOILERS
Year: 1876

page_text: (- LETTERS PATENT to Charles Asbury, of Balsall Heath, near Birmingham, in
the County of Warwick, Mechanical Engineer, for the Invention of "IMPROVE-
MENTS IN STEAM BOILERS."
aled the 12th May 1876, and dated the 18th January 1876.
PROVISIONAL SPECIFICATION left by the said Charles Asbury at the Office
of the Commissioners of Patents on the 18th January 1876.
CHARLES ASBURY, of Balsall Heath, near Birmingham, in the County of Warwick,
Mechanical Engineer. "IMPROVEMENTS IN STEAM BOILERS."
My Invention has reference to steam boilers composed of sets of tubes of large
diameter, and my said Invention consists of the combinations or arrangements
herein after described of the said sets of tubes and their connections.
In constructing a steam boiler according to my Invention I arrange side by side
a set of, by preference, three horizontal tubes of large diameter, the said tubes
being in close contact; and I arrange, side by side, under the said set of horizontal
tubes a similar set of inclined tubes, the highest ends of the said inclined tubes
being situated at the back of the heating chamber in which the tubes are fixed.
The back or highest ends of the bottom inclined tubes are prolonged beyond the
back ends of the top horizontal tubes, and over the said prolonged back ends of the
inclined tubes is a large cross tube. This cross tube is connected to each of the
inclined tubes by vertical or inclined tubular connections, and to each of the hori-
zontal tubes by horizontal tubular connections. Or the cross tube may be fixed
directly on the prolonged back ends of the inclined tubes instead of being connected
thereto by small connecting tubes.
By the arrangement described of the large cross connecting tube the steam
pressure is equalized in the whole of the top horizontal tubes and the water is
separated from the steam as the latter rises from the set of bottom inclined tubes,
thereby tending to prevent priming. The said cross tube and its connections also
preserve the water at the same level in the whole of the top horizontal tubes. By
the inclination described of the bottom set of tubes the steam generated in them
rises with great freedom to the top set of horizontal tubes.
The space underneath the lower inclined set of tubes is divided by a longitudinal
vertical division under the middle tube, thus forming two channels. The flame
and heated air from the boiler furnace first pass between the two sets of tubes

page_text: from the front ends to the back ends, and after traversing the two bottom channels
under the inclined tubes escape to the flue. For gaining access to the tubes one
end of each tube may be provided with a man-hole closed by a cover.
The large cross connecting tube at the rear ends of the two sets of tubes may be
dispensed with, and the rear ends of each pair of tubes of the upper and lower sets
may be directly connected together by straight or curved connections rivetted to
the ends of the tubes. Or instead of separate connections a connecting tube or
junction piece may be made in one piece with the top horizontal tube, and con-
nected to the side of the bottom inclined tube, and instead of inclining the bottom
tubes towards the front or furnace end of the boiler, one half of each bottom tube
may be inclined in one direction and the other half in the other direction, the
middle or highest part of this angular tube being joined to the upper horizontal
tube at or near the middle of the latter.
In combination with the two sets of horizontal and inclined tubes described a
set of horizontal tubes below the set of inclined tubes may be employed. This
last set of horizontal tubes constitutes a water heater, the heated air from the
boiler furnace circulating about the said water heater before it escapes to the flue.
Although I have described a boiler composed of sets of three tubes of large
diameter, yet for large boilers more than three tubes may be used in each set and
more than two sets may be employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Asbury in the Great Seal Patent Office on the 13th July
1876.
CHARLES ASBURY, of Balsall Heath, near Birmingham, in the County of Warwick,
Mechanical Engineer. "IMPROVEMENTS IN STEAM BOILERS,"
My Invention has reference to steam boilers composed of sets of tubes of large
diameter, and my said Invention consists of the combinations or arrangements,
herein-after described, of the said sets of tubes and their connections.
In constructing a steam boiler according to my Invention I arrange side by side
a set of, by preference, three horizontal tubes of large diameter, the said tubes
being in close contact; and arrange side by side under the said set of horizontal
tubes a similar set of inclined tubes, the highest ends of the said inclined tubes
being situated at the back of the heating chamber in which the tubes are fixed.
The back or highest ends of the bottom inclined tubes are prolonged beyond the
back ends of the top horizontal tubes, and over the said prolonged back ends of
the inclined tubes is a large cross tube. This cross tube is connected to each of the
inclined tubes by vertical or inclined tubular connections, and to each of the hori-
zontal tubes by horizontal tubular connections. Or the cross tube may be fixed
directly on the prolonged back ends of the inclined tubes instead of being connected
thereto by small connecting tubes.
By the arrangement described of the large cross connecting tube the steam
pressure is equalized in the whole of the top horizontal tubes, and the water is
separated from the steam as the latter rises from the set of bottom inclined tubes,
thereby tending to prevent priming. The said cross tube and its connections also
preserve the water at the same level in the whole of the top horizontal tubes. By
the inclination described of the bottom set of tubes the steam generated in them
rises with great freedom to the top set of horizontal tubes.
The space underneath the lower inclined set of tubes is divided by a longitudinal
vertical division under the middle tube, thus forming two channels. The flame
and heated air from the boiler furnace first pass between the two sets of tubes from
the front ends to the back ends, and after traversing the two bottom channels under
the inclined tubes escape to the flue. For gaining access to the tubes one end of
each tube may be provided with a man-hole closed by a cover,

page_text: The large cross connecting tube at the rear ends of the two sets of tubes may
be dispensed with, and the rear ends of each pair of tubes of the upper and lower
sets may be directly connected together by straight or curved connections rivetted
to the ends of the tubes. Or instead of separate connections a connecting tube or
junction piece may be made in one piece, with the top horizontal tube and con-
nected to the side of the bottom inclined tube; and instead of inclining the bottom
tubes towards the front or furnace end of the boiler one half of each bottom tube
may be inclined in one direction and the other half in the other direction, the
middle or highest part of this angular tube being joined to the upper horizontal
tube at or near the middle of the latter.
In combination with the two sets of horizontal and inclined tubes described a
set of horizontal tubes below the set of inclined tubes may be employed. This last
set of horizontal tubes constitutes a water heater, the heated air from the boiler
furnace circulating about the said water heater before it escapes to the flue.
I will now proceed to describe with reference to the accompanying Drawings,
the manner in which my Invention may be carried into effect.
Figure 1 represent in longitudinal section, Figure 2 in front elevation, Figure 3
in back elevation, and Figure 4 in plan, a steam boiler constructed according to
my Invention. The same letters of reference indicate the same part in Figures
1, 2, 3, and 4.
a, a, a, is the set of horizontal top tubes, and b, b, b, is the set of inclined tubes
below the top tubes a, a, a, the highest ends of the said inclined tubes being
situated at the back of the heating chamber. The back or highest ends of the
bottom inclined tubes b, b, b, are prolonged beyond the back ends of the top hori-
zontal tubes a, a, a, (see Figure 1), and over the said prolonged back ends is a
large cross tube c. This cross tube c is connected to each of the bottom inclined
tubes b by vertical tubular connections d, and to each of the top horizontal tubes a
by horizontal tubular connections e. I prefer to construct the tubular connecting
pieces d, e, in parts, as herein-after explained, but I do not limit myself thereto.
Under the inclined tubes b, b, b, a set of horizontal tubes or slightly inclined
tubes fff may be used for the purpose of heating the water before it passes to the
upper tubes. When bottom inclined tubes are used it is preferred to slightly incline
them from the furnace end to the back end of the heating chamber as represented.
The space between the middle inclined set of tubes b, b, b, is divided by a longi-
tudinal vertical division at g into two channels. When the lower water heating
tubes are used the longitudinal division is dispensed with; is the furnace or
fire-place of the boiler under the front end of the top horizontal set of tubes a, a, a.
The flame and heated air from the furnace pass between the two sets of tubes a, a, a,
and b, b, b, from the front ends to the back, and then traverse the two bottom
channels under the inclined tubes, and after passing under the bottom tubes f, f,
escape to the flue i.
The boiler constructed as described may be sent out in detached tubes to facilitate
transit, the connecting pieces which I use permitting the boiler tubes to be readily
connected together. By the inclination of the middle and bottom tubes (when
bottom tubes are used) the steam escapes very freely into the cross tube c. By
combining the cross tube c with the horizontal and inclined tubes an equal height
of water is maintained in each of the top tubes a, a, a. The said cross tube c also
maintains an equal steam pressure in each of the said top tubes, and the violent
flow or passage of steam from the bottom and middle tubes f, b, is checked before
it enters the upper tubes a, a. This passage of the steam to the cross tube c also
separates the steam from the water and prevents or diminishes priming. The
bottom tubes f besides serving as water heaters also receive the greater part of the
deposited lime salts, which are thrown down mainly during the heating of the
water in the said tubes. For the purpose of removing the line salts deposited in
the bottom tubes ƒ a pipe may be fixed at the bottom of each tube. This pipe is
closed at one end, and its sides are perforated through the entire length of the tube

page_text: to the blow off cock. The lime salts deposited in the pipe are blown off in the
usual way.
Figure 5 represents an arrangement of my Invention, in which the back ends
of the set of inclined tubes b, b, b, do not extend beyond the back ends of the set
of top horizontal tubes, the cross tube c in this arrangement being connected to the
ends of the inclined tubes b, b, b, by inclined connecting pieces l.
Figures 6, 7, 8, and 9, represent arrangements of my Invention in which the cross
tube at the back of the top set of horizontal tubes is dispensed with. In the
arrangement Figure 6, each of the inclined tubes b is connected to the top tube a
above it by a connecting tubular junction m. In the arrangement Figure 7, the
prolonged end of each inclined bottom tube b is connected to the top tube above it
by the curved tubular junction m, passing from the side of the bottom tube to the
end of the top tube. In the arrangement Figure 8, each bottom inclined tube is
connected to the top tube above it, end to end, by a curved tubular junction p.
In the arrangement Figure 9 the bottom tubes 6 are angular, that is, the two
halves of the tubes are inclined from the middle downwards, the middle or highest
part of these angular tubes b, b, being connected to the upper horizontal tubes a
by junction pieces at q near the middle of the said horizontal tubes.
In some of the arrangements described, namely, those represented in Figures
1, 5, 6, and 9, the junction or connecting pieces between the horizontal and inclined
tubes may be made in halves for convenience of attaching and detaching the tubes.
In these cases I prefer to construct the junction or connecting pieces in the ways
represented in Figure 10. In the arrangement marked A, Figure 10, the flanged
halves a, b, are respectively fixed to the two tubes to be connected together. The
part a has on its under side an annular rib which takes into a corresponding
depression or seat in the part b, asbestos or other packing being placed between the
parts of the joint. The two halves or parts a, b, are secured together by a central
screw pin, as shown. In the arrangement marked B a V joint is made between
the halves a, b, and in the arrangement marked C an inclined or conical joint is
made between the halves or parts a, b. In the arrangement marked D the half b
is reduced in diameter at its upper end to form a seat for the part or half a, the
two parts a, b, being connected together by the screw pins c, c.
Although I have described and represented a boiler composed of sets of three
tubes of large diameter, yet for large boilers more than three tubes may be used in
each set and more than three sets may be employed.
Having now described the nature of my Invention and the manner in which the
same is to be performed, I wish it to be understood that I do not limit myself to
the precise details herein described and illustrated, as the same may be varied
without departing from the nature of my Invention; but I claim as my Invention
of improvements in steam boilers composed of sets of tubes of large diameter,-
First. The arrangements or combinations of the parts of tubular boilers, herein-
before described and illustrated in Figures 1, 2, 3, 4, and 5 of the accompanying
Drawings, that is to say, the combination with a set of horizontal top tubes placed
side by side of a similar set of inclined tubes under the said horizontal top set, the
said inclined tubes being used either with or without a horizontal or inclined set
of tubes below them, substantially as described and illustrated. Also the combi-
nation with the inclined and horizontal sets of tubes of a large cross connecting
tube for preserving the same water level in the whole of the set of horizontal top
tubes and equalizing the steam pressure therein, substantially as described and
illustrated.
Secondly. The several arrangements herein-before described and illustrated in
Figures 6, 7, and 8, of the accompanying Drawings, for connecting together the
horizontal and inclined set of tubes when the cross connecting tube at the back ends
of the horizontal set of tubes is dispensed with.
Thirdly. The combination with a set of horizontal top tubes of a set of angular
tubes, as herein-before described and illustrated in Figure 0 of the accompanying
Drawings.

page_text: Lastly. The construction of the junction pieces for connecting the horizontal and
inclined or angular tubes together, as herein-before described and illustrated in
Figure 10 of the accompanying Drawings.
In witness whereof, I, the said Charles Asbury, have hereunto set my hand
and seal this Twelfth day of July, in the year of our Lord One thousand
eight hundred and seventy-six.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
CHARLES ASBURY. (L.S.)