improvements in tubular steam Bollers.
Year: 1886

page_text: improvements in tubular steam Bollers.
We WILLIAM JOHN FRASER of 98 Commercial Road, East, and FRANCIS SANDERS
MORRIS of Middleton Lodge, Tottenham, both in the county of Middlesex,
Engineers do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in multitubular steam boilers of all
kinds, the improvements having for object to provide an increased and more
efficient heating surface than hitherto whereby steam is more rapidly generated
and at a less expense of fuel than by the ordinary construction of boiler. At the
same time rapid circulation takes place throughout the boiler.
Our invention consists in combining water-tubes with fire tubes, by inserting
such water-tubes within the fire tubes in the manner substantially as hereinafter
more particularly described.
In carrying out our invention for vertical boilers the tube through which the fire
passes (and which we call the fire tubes) have their lower ends attached and
expanded into the top of the fire box and their upper ends inserted in the bottom
of a secondary or upper combustion chamber above the fire box and from this
chamber the products of combustion are carried away by an uptake of the usual
form either from the sides of the boiler or vertically in tubes or one central uptake.
The water tubes pass up through the centre of the above fire tubes and have their
lower ends curved and attached and expanded into the sides or walls of the fire box
of the boiler in any suitable position and their upper ends carried up and expanded
into the top plate of the before mentioned secondary combustion chamber or into
the sides of the same as may be considered most effective for promoting and
increasing the circulation.
The water-tubes (made either taper or parallel) or some of them are brought
through their fire tubes into the fire-box and are of sufficient length and so curved
as to enable their lower ends to be expanded into the walls or sides of the said
fire-box.
The products of combustion being conducted through the annular spaces formed
by the fire and water-tubes become thoroughly and substantially divided and well
utilized before they reach the secondary combustion chamber and they finally pass
out from the boiler through an uptake connected with this upper chamber.
We. sometimes combine a large central vertical fire-tube with the fire-tubes
described above which connects the upper and lower combustion chambers and
in this fire-tube we hang from the top tube plate of the secondary combustion

page_text: chamber a series of pendent circulating water-tubes; when employing this arrange-
ment we find that it is sometimes only necessary to provide the outer rings of fire
tubes with the central water-tubes passing through them.
Amongst the advantages of our improved boiler may be mentioned the following
videlicet -
-:
We overcome the difficulty of obtaining good general circulation hitherto so
difficult in vertical boilers with pendent water tubes as we connect the body
of water in that part of the boiler generally having defective and sluggish
circulation with the water in most active circulation and it will be obvious that
our arrangement produces the desired effect and obviates local circulation so
prejudicial to the evaporative power of most vertical boilers with pendent tubes.
We find it advantageous to arrange our combined water and fire tubes in the
locomotive and marine type of boiler, in which case we have the water tubes
passing through the fire-tubes which latter have a diameter sufficient to allow
of annular fire spaces around the water-tubes; the fire-tubes are expanded at one
end into the furnace tube plate as in the ordinary manner; their other ends open
into a smoke box or combustion chamber having an ordinary uptake and we
provide a water-space at the back end of the smoke-box; the water-tubes inside
the fire-tubes are carried through the smoke-box into the water space beyond it;
their other ends pass into or through the fire-box and are expanded into the inner
plate forming the water casing between the fire-box and the outside shell of the
boiler; or the water tubes may be inserted in the fire tubes in the form of
the letter U, and in this case it will be obvious that one length of tube bent
to the desired pitch will form two water tubes and so dispense with the joint
otherwise necessary to secure the water-tubes at both ends of the boiler or into the
fire box as above described; the U bend projects into the furnace end or combustion
chamber any desired distance and is only attached at the smoke box or furnace
end of the boiler or if preferable; the U bend may be in the smoke box end
of the boiler the other ends projecting into the furnace and are expanded into the
wall forming the inside of the water casing or back of the fire box.
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicants.

page_text: Improvements in Multitubular Steam Boilers.
We, WILLIAM JOHN FRASER, of 98, Commercial Road, East, and FRANCIS
SANDERS MORRIS, of Middleton Lodge, Tottenham, both in the County of
Middlesex, Engineers, 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 multitubular steam boilers of all
kinds, the improvements having for object to provide an increased and more
efficient heating surface than hitherto, whereby steam is more rapidly generated
and at a less expense of fuel than by the ordinary construction of boiler. At the
same time rapid circulation takes place throughout the boiler.
Our invention consists in combining water-tubes with fire-tubes, by inserting
such water-tubes within the fire-tubes in the manner substantially as hereinafter
more particularly described.
In carrying out our invention for vertical boilers the tubes through which the
fires passes (and which we call the fire-tubes) have their lower ends fixed into the
fire-box and their upper ends fixed into a secondary or upper combustion chamber
above the fire-box, and from this chamber the products of combustion are carried
away by an uptake of the usual form either from the sides of the boiler or
vertically in tubes or one central uptake. The water-tubes pass up through the
above fire-tubes, and have their lower ends curved and attached to the sides or
walls of the fire-box of the boiler in any suitable position, and their upper ends
carried up and fixed in the top plate of the before mentioned secondary combustion
chamber, or in the sides of the same as may be considered most effective for
promoting and increasing the circulation.
The water tubes (made either taper or parallel) or some of them are brought
through their fire-tubes into the fire-box and are of sufficient length and so curved
(if necessary) as to enable their lower ends to be expanded into or otherwise
attached to the walls or sides of the said fire-box.
The products of combustion, being conducted through the annular spaces formed
by the fire and water-tubes, become thoroughly and substantially divided and well
utilized before they reach the secondary combustion chamber, and they finally pass
out from the boiler through an uptake connected with this upper chamber.
We sometimes combine a large central vertical fire-tube with the fire-tubes
described above, which connects the upper and lower combustion chambers, and
in this fire-tube we hang from the top tube-plate of the secondary combustion
chainber a series of pendent circulating water tubes; when employing this
arrangement we find that it is sometimes only necessary to provide the outer
rings of fire-tubes with central water-tubes passing through them.
We find it advantageous to arrange our combined water and fire-tubes in
locomotive and marine boilers of the vertical horizontal or combined types, in
which case we have the water-tubes passing through the fire-tubes as herein before
described.
In the case of. horizontal boilers of the locomotive type, the fire-tubes can be
expanded at one end into the furnace tube-plate as in the ordinary manner, their
other ends opening into a smoke-box or combustion chamber having an ordinary
uptake, and we provide a water-space at the back end of the smoke-box; the
water-tubes inside the fire-tubes are carried through the smoke-box into the
water space beyond it; their other ends pass into or through the fire-box and are

page_text: expanded into the inner plate forming the water casing between the firebox and
the outside shell of the boiler; or the water-tubes may be inserted in the fire-tubes
in the form of the letter U, and in this case it will be obvious that one length of
tube bent to the desired pitch will form two water-tubes and so dispense with the
joint otherwise necessary to secure the water-tubes at both ends of the boiler or
into the fire-box as above described; the U-bend projects into the furnace end or
combustion chamber any desired distance and is only attached at the smoke-box
or furnace end of the boiler, or, if preferable, the U-bend may be in the smoke-box
end of the boiler, the other ends projecting into the furnace and being expanded
into the wall forming the inside of the water casing or back of the fire-box.
It will be obvious that our improved combined fire and water-tubes can be fixed
to other suitable parts of the boilers according to their type or construction.
In order to enable our invention to be fully understood we will proceed to
describe the same by reference to the accompanying drawing in which figure 1
represents a vertical section of a vertical multitubular steam boiler provided with
combined fire and water tubes according to our invention and in which we arrange
a ring of pendent circulating water tubes and a ring of water-tubes fixed at both
ends, all the water-tubes passing through fire-tubes, the boiler being shewn also
provided with a large central fire-tube; figure 2 is a sectional plan on line x, x, of
figure 1; figure 3 is a detached vertical section drawn to a larger scale of one of
the combined water and fire-tubes, shewing also a part of the top and bottom
plates of the secondary or other combustion chamber and top plate and side of the
fire-box; figure 4 is a horizontal section of the said combined fire and water-tubes;
figure 5 is a section of a vertical boiler having an outer ring of water-tubes curved
at their lower ends and expanded into the fire-box, and also having a central
circulating water-tube and a series of pendent circulating water-tubes passing
through their fire-tubes; figure 6 is a horizontal section on line C. D. of figure 5;
figure 7 is a vertical section of combined fire and water-tubes (shewing a portion
of the top and bottom plates of the secondary combustion chamber and part of the
fire box) in which the lower end of the water-tube is extended below the fire-bars
and attached to the wall of the fire-box.Similar letters in all the figures represent
similar or corresponding parts.
Referring to figure 1, a, represents the shell of the boiler which shell is of
ordinary construction; b, b, (figures 1, 2, 3 and 4) are the fire-tubes; c, c, are the
pendent circulating water-tubes, which are inserted within some of the fire-
tubes b, b; d, d, are the circulating water-tubes passing through the other
fire-tubes b, b, and expanded into or otherwise fixed in the walls or sides of the
fire-box as shewn in figures 1, and 3; e, e, are the spaces left around the water-
tubes and between the same and the fire-tubes b, b; f, is the tube plate from which
the pendent circulating water-tubes are suspended and into which the upper ends
of the water-tubes d, d, are expanded; g, is the chamber which we call the
secondary combustion chamber of which the tube plate f, forms the top; h, is
the bottom plate of the chamber g, in which plate h, are fixed the upper ends of
the fire-tubes b, b; i, is the bottom tube plate which forms the top of the ordinary
or primary combustion chamber or fire box j, and into which are expanded or
otherwise fixed the lower ends of the fire-tubes b; k, is the large central fire-tube
leading from the fire box j, to the secondary combustion chamber g; 1, is a baffle
in the fire-tube k, which baffle 1, can be operated by a handle m, so as to raise or
lower the same for the purpose of regulating the draught through the fire-tubes b;
n, is the uptake for carrying the products of combustion from the chamber ģ, out of
the boiler.
By our improvements the products of combustion formed in the primary com-
bustion chamber j, are conducted through the annular spaces e, e, around the water
tubes d, d, and become thoroughly and substantially divided and well utilized
before they reach the secondary combustion chamber g, whence they pass through
the uptake n, and out of the boiler; the water circulates from the lower part of the
boiler up through the water tubes d, to the upper part of the boiler and back to

page_text: the lower ends of the said tubes d; the water also circulates through the pendent
water-tubes c, the direction of circulation through the water tubes d, being indi-
cated by the arrows in figure 3.
In the boiler shewn in figures 5 and 6, the arrangement of the water and
fire-tubes is substantially the same as that hereinbefore described when referring to
figures 1, 2, 3 and 4, but we have shewn the boiler provided with a central water-
tube o, to facilitate circulation from underneath the upper fire-tube plate and
amongst the tubes b, b; a¹, a¹, a¹, a¹, are stay tubes for staying the upper 'and
lower fire-tube plates. In addition to the stay tubes a¹, we also employ the usual
stays 6, connecting the tube plate f, with the top of the boiler; n, represents the
uptake which by reason of the central water tube o, being employed, is placed at
the side of and outside the boiler instead of passing through the centre thereof as
in figure 1. For the purpose of equalizing the distribution of the heat we some-
times employ two of such uptakes n, one at each side of the boiler; p, is a door to
allow of cleaning out the chamber g; q, q, are hand-holes for cleaning out other
parts of the boiler; the bottom tube plate i, is shewn flat instead of being dished
as in figure 1.
We sometimes, as shewn in figure 7, fix the water tubes into the fire-box or
primary combustion chamber below the furnace bars which enables the tubes to be
easily cleaned, renewed and repaired without removing the shell from the fire box;
the lower ends of the water-tubes are attached to the fire-box below the fire-bars
by crosses or suitable attachments having plugs or screw-caps which allow of the
tubes being readily cleaned in either direction.
The application of our improved combined fire and water tubes to locomotive
and marine boilers will be obvious without further description.
Amongt the advantages to be derived from the use of boilers constructed
according to our invention the following appear to us of primary importance,
videlicet, a great economy is effected in the consumption of fuel owing to the
increased and more efficient heating surface; we get over the difficulty of local
circulation attending most boilers having pendent water-tubes and by our improved
arrangement of water-tubes put in active circulation that body of water usually
very sluggish; our improved arrangement of tubes admits of a considerable
reduction in the size of a boiler as compared with those of ordinary construction.
It will be obvious that our improvements are applicable to other boilers than
steam boilers, such for example as hot water boilers.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. In multitubular steam boilers the use of combined water and fire-tubes in
which the ends of the water-tubes extend beyond the fire-tubes and are expanded
into or otherwise fixed to the walls of the fire-box or combustion chamber.
2. The improved combined fire and water-tubes for multitubular steam boilers
substantially as herein before described and illustrated in figures 3, 4, and 7 of the
accompanying drawing.
3. The manufacture and use of the improved multitubular steam-boilers herein-
before described and illustrated in figures 1, 2, 5 and 6 of the accompanying
drawing.