Improvements in Tubulous Steam Boilers.
Year: 1896

page_text: .Date of Application, 26th Mar., 1896
4000 Accented
13th Mor 1807
PROVISIONAL SPECIFICATION.
Improvements in Tubulous Steam Boilers.
I, DAVID PURVES, of Wyborne Gate, Birkdale, Southport, Lancashire,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to, tubulous steam boilers.
In one form of boiler constructed according to my invention employ two
upper water drums of comparatively small diameter connected to a lower water
drum about midway between same by groups of sloping water tubes said upper
drums being also connected by water tubes to outside water drums about on the
same line with the lower central drum. Between these three drums a pair of
fire grates are arranged. Some of the tubes connecting the outside water
drums with the upper water drums may be curved arranged or shaped so as to
form a close wall of tubes and thus prevent the passage of the gases between
The other groups of tubes connecting the upper druns with the lower
central drum have each a wall of refractory material backing same but extending
only for a portion of the length of each group. This prevents the fire passing
directly through each group of tubes and causes it if the openings are at each
end, to pass between the tubes of each group and escape at each end into a
chamber formed by the refractory walls. The wall may however be formed or
partially formed of tubes curved arranged or shaped so as to form a close wall
where required.
same.
Above the chamber formed by the refractory walls is situated a boiler shell
of comparatively large diameter having water connections with the upper drums
and a combustion chamber formed at or about the middle of same into which.
the gases after travelling along the under side of the boiler can pass.
One or more of the walls of this chamber may consist of a tube plate with
which fire tubes passing through the boiler shell are connected, and through
which fire tubes the gases escape to a flue or chimney situated at the end of
the boiler or if the chamber has more than one tube plate the gases will escape
through the tubes and be taken off at each end of the boiler shell. The side
walls of the chamber may be formed by continuations of the refractory walls
previously mentioned.
Instead of forming the chamber in the boiler shell itself it may be placed
at one end of and outside of same and be formed or built up of refractory or
other suitable material and in this case an opening may be left through each
of the refractory walls which back the tubes at or about one end only so that
the gases will travel to that end, return under the boiler shell pass up into
the built up outside chamber, through the tube plate of the boiler, and out
from the tubes to the flue or chimney.
.
The same arrangement may be employed where the chamber is not built up
outside the shell but is formed in same at one end of the boiler.
Or where the combustion chamber is arranged at the other end to the firing
door the gases may pass directly into same and would not then return under the
main shell and in this case a wall or baffle plate would not actually be necessary.
In the case also of a boiler fired from both ends and having a combustion
chamber at or about the middle of the receiver this wall or baffle plate may be
dispensed with.

page_text: In place of employing the upper water drums however the tubes from the
lower central water drum may pass directly into the boiler shell and in this
case to enable the water tubes to be readily removed they are spaced sufficiently
wide apart that by moving any one laterally to avoid the tube in front it may
be drawn out. Instead of a wall of refractory material backing these tubes
1 may use a perforated plate and close up the end of each fire grate with a
wall of refractory material or of tubes so that the gases will pass between the
tubes and through the perforated plate into the chamber beneath the boiler
shell (which may if desired be protected at this point by an air jacket) and so
out to the combustion chamber (which may be either at the end of the boiler shell,
in the same or between two boilers) through the tube plate and tubes and out to
the chimney. To check the gases passing through the tubes to the perforated
plate I may to this end place a baffle plate in the groups of tubes and to furnish a
further water connection between the lower central drum and the boiler shell
I may employ down pipes of large diameter which may if they pass through the
chamber beneath the boiler shell be encased in an air jacket to shield them from
the heat.
31
.
1000
PHILIP M. JUSTICE,
55 & 56 Chancery Lane, London, Chartered Patent Agent,
For the Applicant.
Improvements in Tubulous Steam Boilers.
I, DAVID PURVES, of Wyborne Gate, Birkdale, Southport, Lancashire,
Engineer, 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 :-
My invention relates to tubulous steam boilers.
To clearly explain my invention I will describe it by reference to the accom-
panying drawings in which are illustrated three types of boilers constructed in
accordance with my invention.
In the form of boiler shown in Figures 1 and 2 I employ two upper water
drums a a of comparatively small diameter connected to a lower water drum b
about midway between same by groups of sloping water tubes c c said upper
drums a being also connected by water tubes d d to outside water drums e e about
on the same line with the lower central drum. Between these three drums ebe
a pair of fire grates ff are arranged. Some of the outer tubes connecting the
drums e with the drums a may be curved as shown in Figure 1 so as to form a close
wall of tubes at the point d, and thus prevent the passage of the gases between
same or the tubes forming the outer rows may be enlarged for the same purpose.
The other groups of tubes c have each a wall of refractory material 9 backing
same but extending only for a portion of the length of each group as shown in
Figure 2. This prevents the fire passing directly through each group of tubes c
and causes it if the openings are at each end to pass between the tubes of each
group c'and escape at each end into a chamber h formed by the refractory walls g.
The walls g may however be formed or partially formed of tubes curved arranged
or shaped so as to form a close wall where required.
Above the chamber is situated a boiler shell i of comparatively large diameter
having water connections ; with the drums a and a combustion chamber k formed

page_text: tor about the middle of same into which the gases after travelling along the nuc
de of the shell i can pass.
One or more of the walls of this chamber may consist of a tube plate with which
re tubes / passing through the boiler shell are connected and through which fire
ubes the gases escape to a flue or chimney m situated at the end of the boiler or if
he chamber has more than one tube plate the gases will escape through the tubes
nd be taken off at each end of the shell i as shewn in Figure 2. The side walls
of the chamberk are formed in this case by continuations of the refractory walls g
plate » forming the top.
Instead of forming the chamber in the boiler shell itself it may be placed at one
end of and outside of same and be formed or built up of refractory or other suitable
material as shown in Figures 3 and 4 and in this case an opening may be left
through each of the refractory walls g at one end only as shown at Figure 4 (or
near the end) so that the gases will travel to that end as shown, by the arrows,
retarn under the shell i through chamber & pass up into the built, up outside
chamber k, through the tube plate of the boiler and out from the tubes / to the flue
or chimney m.
The same arrangement may be employed where the chamber is not built up
outside the shell i but is formed in same at one end of the boiler by means of a
tube plate, a plate a and continuations of the walls g, as shown in Figures 1
and 2.
Or where the combustion chamber è is arranged at the other end to the firing
door the gases may pass directly into the former and would not then return under
the main shell and in this case a wall or baffle plate g would not actually be
necessary so that the gases could pass through between the tubes c to the under side
of the shell i and direct to chamber k.
In the case also of a boiler fired from both ends and having a combustion
chamber k at or about the middle of the shell i as shown in Figure 2 this wall or
baffle plate g may be dispensed with.
In place of employing the water drums a however, the tubes from the water
drum b may pass directly into the boiler shell i as shown in Figures 5 and 6 and in
this case to enable the water tubes e to be readily removed they are spaced as
shown in Figure 6 so that by moving any one laterally to avoid the tube in front
it may be drawn out. Instead of a wall g of refractory material backing these
tubes I may use a perforated plate g so that the gases will pass between the
tubes e and through the perforated plate gl into the chamber & beneath the boiler
shelli and so out to the combustion chamber k (which may be either at one end
of the boiler shell as shown or in the same or between two boilers), through the
tube plate, and tubes and out to the chimney m. To check the gases passing
between the tubes to the perforated plate I may to this end place a baffle plate p
of refractory material in the group of tubes e and to furnish a further water
connection between the lower drum b and the boiler shell i, I may employ down
pipes q of large diameter.
The holes in the perforated baffle plate are preferably so arranged that the
5 gases while being spread over the whole length of the tubes are principally drawn
through towards the bottom and at the front of the boiler.
Any of the boilers described or shown may be provided in addition with cross
tubes as shown in Figures 5 and 6 connecting the drums e e with the drum b and
the boilers are provided with suitable casings shown in these figures which casings
0 may be provided with holes uw at the ends for tube cleaning purposes and with
a removable plate or door for the purpose of enabling the tubes to be
removed.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
5 claim is :-
1. In combination water drums a a connected to lower water drums bande e by

page_text: tubes c c and d d and a boiler shell provided with fire tubes through same and a
combustion chamber k into which the gases pass before entering the fire tubes
substantially as described.
2. In combination water drums a a connected to lower water drums b and e e by
tubes c c and d d and a boiler shell provided with fire tubes through same and a
combustion chamber & the groups of tubes c c having a wall at the back of same
forming a chamber beneath the boiler shell into which chamber the gases pass from
one or both ends of the groups of tubes c before they enter the combustion
chamber k substantially as described.
3. In combination water drums bee connected to a boiler shell by tubes c c d d
said boiler shell having fire tubes through same and a combustion chamber k into
which the gases pass before entering the fire tubes substantially as described.
4. In combination water drums bee connected to a boiler shell by tubes ccdd
said boiler shell having fire tubes through same, a chamber beneath formed by
walls g or perforated plates gl and a combustion chamber k into which the gases
pass before entering the fire tubes substantially as described.
5. The construction of tubulous steam boiler substantially as described and
illustrated in Figures 1 and 2.
6. The construction of tubulous steam boiler substantially as described and
illustrated in Figures 3 and 4.
7. The construction of tubulous steam boiler substantially as described and
illustrated in Figures 5 and 6.
Dated the 10th day of December 1896.
PHILIP M. JUSTICE,
55 & 56 Chancery Lane, London, Chartered Patent Agent,.
For the Applicant.