IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1876

page_text: LETTERS PATENT to Frederick John Rowan, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of "IMPROVEMENTS IN
STEAM ENGINES AND BOILERS."
Sealed the 11th May 1877, and dated the 16th November 1876.
PROVISIONAL SPECIFICATION left by the said Frederick John Rowan at the
Office of the Commissioners of Patents on the 16th November 1876.
FREDERICK JOHN ROWAN, of Glasgow, in the County of Lanark, North Britain,
Engineer. " IMPROVEMENTS IN STEAM ENGINES AND BOILERS."
This Invention relates to steam engines and boilers of the classes described in the
Specification of Letters Patent granted to the late John Martin Rowan (father of
the present applicant) and to Thomas Rogers Horton, and has for its object by
improved modifications and new arrangements to obtain still better results than
those secured by the earlier Invention referred to..
In the improved arrangement of engines which is well adapted for driving the
screw propeller in vessels of war there are six steam cylinders placed horizontally,
two being high pressure, and the steam from each of these two operating simul-
taneously in two low-pressure cylinders, the whole thus forming a pair or two sets
with three cylinders in each set. Each high-pressure cylinder is in the plane of the
crank shaft with one of its two low-pressure cylinders on the inner side of it and at
a slightly higher level, and with the other on the outer side at a lower level; or the.
Rods
inner cylinder may be placed lower than the shaft, and the outer one higher.
from the three pistons of each set pass out through stuffing boxes at the outer ends
of the cylinders and are fixed to one crosshead; whilst the rods of the two low-
pressure cylinders extend also inwards, and passing through stuffing boxes at the
inner ends of the cylinders proceed across, one above and the other below the shaft,
to a crosshead working on guides and connected to the crank by a return connecting
rod. The condenser and pumps are arranged opposite to the steam cylinders with
the shaft between them, the circulating and air pumps being worked by rods
attached to the higher low-pressure pistons, whilst the feed and bilge pumps are
worked by rods attached to the outer low-pressure pistons; or circulating pumps
worked by an independent engine may be used as in some existing engines. The

page_text: cylinder valves are worked by means of rocking shafts placed over the smaller
pumps, and provision is made in connection with them for working all three
cylinders of each set with low-pressure steam direct from the boilers.
The improved boilers are built up like the boilers described in the earlier Speci-
fication herein-before referred to of sets of vertical or nearly vertical tubes fixed
into upper and lower horizontal cylinders or chambers, the ends of the tubes being
bended so as to join the surfaces of the cylinders or chambers normally or at right
angles.
In one arrangement eight of the improved boilers are combined in one set, four
with their furnaces facing forwards and four with their furnaces facing aft. In each
boiler of the set there are two lower horizontal cylinders or chambers set somewhat
apart, and from these tubes extend upwards to a single upper horizontal cylinder or
chamber.
The space between the two sets of tubes forms a combustion chamber, which
is provided with a bottom or hearth of fire-brick. Each boiler has a single external
brick fire-place; which is supplied with air and fuel by an inlet at the top, the air
being forced by means of a blower or fan in between two conical shells fixed in the
inlet, whilst the coal or fuel is fed in regularly and automatically from a hopper
above by means of a pair of rollers, or of a single revolving paddle, or of one or
more reciprocating feeders.
The fire gases proceed from the external fire-place into the combustion space
herein-before referred to, and then diverging pass amongst the tubes on either side
and over inner partitions placed between one or more outer rows of tubes and the
next inner rows. From the tops of the inner partitions the fire gasses pass down
between those partitions and outer partitions, and thence into a space between the
boiler and an enclosing casing, and finally to the uptake.
The upper horizontal cylinder or chamber of each boiler may communicate with
a steam chest at a higher level, but when the boilers are intended for a vessel of
war, in which case it is important to keep all parts below the water line, the follow-
ing arrangements are adopted: A curved diaphragm is fixed across the cylinder,
and extending nearly from end to end, so that any water issuing from the moutlis
of the tubes may strike against its under side, whilst the steam separating from the
water passes round the ends of the diaphragm to its upper side. A second short
diaphragm is interposed at one end where the main one does not extend over all the
tubes. From the space above the diaphragm the steam passes by one or more
pipes to a horizontal cylinder or chest at the same level, the pipe projecting inside
the steam chest down into a pocket, from which a pipe proceeds down to the
bottom of the boiler, so that any water carried over into the steam chest is thrown
into the descending pipe and separated.
The action of the fire gases on the vertical or nearly vertical tubes produces
strong upward currents in these tubes, and ample provision is made by pipes or
tubes for the return current to the bottom of the boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederick John Rowan in the Great Seal Patent Office on the 14th
May 1877.
FREDERICK JOHN ROWAN, of Glasgow, in the County of Lanark, North Britain,
Engineer. "IMPROVEMENTS IN STEAM ENGINES AND BOILERS."
My said Invention relates to steam engines and boilers of the classes described in
the Specification of Letters Patent granted to the late John Martin Rowan and to
Thomas Rogers Horton, and dated 11 November 1869 (No. 3253), and has for its
object by improved modifications and new arrangements to obtain still better results
than those secured by the earlier Invention referred to.

page_text: In my improved arrangement of engines, which is well adapted for driving the
screw propeller in vessels of war, there are six steain cylinders placed horizontally, two
being high pressure, and the steam from each of these two operating simultaneously
in two low-pressure cylinders, the whole thus forming a pair or two sets, with three
cylinders in each set. Each high-pressure cylinder is in the plane of the crank
shaft, with one of its two low-pressure cylinders at a higher level on the inner
side of it, and with the other on the outer side, and at a lower level. Or the
inner cylinder may be placed lower than the shaft, and the outer one higher.
My improved boilers are built up like the boilers described in the earlier Speci-
fication herein-before referred to of sets of vertical or nearly vertical tubes fixed into
upper and lower horizontal cylinders or chambers, the ends of the tubes being bended
so as to join the surfaces of the cylinders or chambers normally or at right angles.
In each boiler or section of the boilers a space constituting a combustion chamber
is formed between sets of the vertical tubes, and is provided with a bottom or
hearth of fire-brick; and in connection with each combustion chamber there is a
single external brick fire-place, which is supplied with air and fuel by an inlet at
the top, the air being forced by means of a blower or fan in between two conical
shells fixed in the inlet, whilst the coal or fuel is fed in regularly and automatically
from a hopper above by means of a pair of rollers or a single revolving paddle, or
of one or more reciprocating feeders. The fire gasses proceed from the external
fire-place into the combustion space herein-before referred to, and then diverging
pass amongst the tubes on either side and over inner partitions placed between
one or more outer rows of tubes and the next inner rows. From the tops of the
inner partitions the fire gases pass down between those partitions and outer par-
titions, and thence into a space between the boiler and an enclosing casing, and
finally to the uptake.
Special arrangements, berein-after particularly described, are provided to facilitate
the separation of the steam from the water to promote efficient circulation, and to
admit of the steam chests being placed low in war ships.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append three sheets of explanatory
drawings to be berein-after referred to, and representing examples of my improved
steam engines and boilers.
In these Drawings the same reference numerals are used to mark the same or
like parts wherever they are repeated.
A modification of my improved engines is shown on Sheet 1 of the accompanying
Drawings, Figure 1 being a sectional plan; Figure 2, a longitudinal vertical section;
and Figure 3, a sectional end elevation. In these engines two high-pressure
cylinders 1 are placed at the level of the crank shaft 2, and each high-pressure
cylinder bas in connection with it two low-pressure cylinders 3, 4, placed one a
little higher and the other a little lower than the crank shaft 2. In the example
delineated the inner cylinders 3 are placed higher than the outer ones 4; but, as
already mentioned, this arrangement may be reversed. Rods 5, 6, 7, from the
three pistons of each set pass out through stuffing boxes at the outer ends of the
cylinders 1, 3, 4, and are fixed to one cross head 8, whilst the rods 6, 7, of the two
low-pressure cylinders 3, 4, extend also inwards, and passing through stuffing boxes
at the inner ends of the cylinders proceed across, one above and the other below
the crank shaft 2, to a cross head 9 working in guides 10, and connected to the
crank by a return connecting rod 11.
It will be unnecessary to describe many of the minor details of construction, as
these will be understood from the Drawings, and as they are like those of existing
engines of a similar type having the cylinders on one side of the crank shaft, and most
of the other parts on the other side thereof. The condensers 12 (by preference of
the tubular surface kind) are placed in the middle of the space opposite to the
cylinders 1, 3, 4, with the circulating pumps 13 placed above them, and worked by
rods 14 attached to the pistons of the higher low-pressure cylinders 3, whilst the

page_text: air pump 15, and the feed and bilge pumps are worked by a rod 16 attached to the
pistons of the outer low-pressure cylinders 4.
If preferred circulating pumps worked by an independent engine may be used
as in some existing engines. The cylinder valves are worked by rocking shafts 17
carried in bearings 18 placed partly over the outer pumps, and provision may be
made in connection with the valves for working all three cylinders of each set
with low-pressure steam direct from the boilers.
Each
A modification of my improved boilers is shown in sectional plan and in sectional
elevation in Figures 4 and 5, on Sheet 2 of the accompanying Drawings, whilst
Figure 6, on Sheet 3, is a vertical section as at right angles to Figure 5. In this
example eight boilers (or sections) are combined in one set, four with their furnaces
facing forwards and four with their furnaces facing aft. In each boiler of the set
there are two lower horizontal cylinders or chambers 19 set somewhat apart, and
from them tubes 20 extend upwards to a single upper horizontal cylinder or
chamber 21. The space 22 between the two sets of tubes 20 forms a combustion
chamber which is provided with a bottom or hearth 23 of fire-brick.
boiler has a single external brick fire-place 24 which is supplied with air and
fuel by an inlet 25 at the top, the air being forced by means of a blower and
fan through pipes 26 and in between two conical shells 27 fixed in the inlet 25
whilst the coal or fuel is fed in regularly and automatically from a hopper 28
above by means of a pair of rollers 29 (or otherwise as herein-after explained).
The fire-place 24 is fitted with a grating 30 at its bottom which can be turned
down periodically to drop the very small residues of the fuel which remains in
this system of furnace, and provision is made for admitting some of the forced
air under the grating 30 when the nature or quality of the coal employed
renders it desirable. The fire gases proceed from the external fire-place 24 by
a flue 31 into the combustion space 22, and then diverging pass amongst the
tubes 20 on either side and over inner partitions 32. The course of the fire gases is
next down between the inner partitions 32 and outer partitions 33 into spaces 34
between the boilers and within an enclosing casing 35 and thence to the uptake 30.
The upper horizontal cylinder or chamber 21 of each boiler may communicate with
a steam chest at a higher level; but when the boilers are intended for a vessel of
war, in which case it is important to keep all parts below the water line, the
arrangements shown in the Drawing are adopted. A curved diaphragm 37 is fixed
across the cylinder 21 and extends nearly from end to end, so that any water issuing
from the mouths of the tubes 20 may strike against its under side, whilst the steam
separating from the water passes round the ends of the diaphragm 37 to its upper
side. A second short diaphragm 38 is interposed at one end where the main one
does not extend over all the tubes 20. From the space. above the diaphragm 37 the
steam passes by one or more pipes 39 to a horizontal cylinder or chest 40 at the
same level, each pipe 39 projecting inside this steam chest 40 down into a pocket 41
from which a pipe 42 proceeds down to the bottom of the boiler, so that any water
carried over into the steam chest is thrown into the descending pipe 42 and
separated from the steam. At the inner end of each combustion space 22 a large
vertical tube 43 is connected at its upper end to the upper horizontal cylinder 21,
whilst its bottom end communicates by two branches 44 with the inner ends of the
lower horizontal cylinders 19. The action of the fire gases on the vertical or nearly
vertical tubes 20 produces strong upward currents in these tubes, and the necessary
return current takes place down the large tube 43, whilst any water carried over
into the steam chests 40 passes down by the pipes 42 and contributes to the supply
of water in the lower cylinders 19 necessary to maintain the upward currents in the
tubes 20.
For working the mechanical fuel feeding apparatus a horizontal shaft 45 is
carried along in front of the boilers and is fitted with worms 46 each with an
engaging and disengaging clutch for driving worm wheels forming part of the feed-
ing gearing. In the modification of this gearing shown in Figures 4, 5, 6, two fluted

page_text: or grooved rollers 29 placed horizontally are employed, and are turned so as to
carry the fuel down between them. In Figure 7, on Sheet 3 of the Drawings, a
modification is shown in vertical section, in which a conical screw 48 is employed,
this screw being on a vertical spindle having on it a worm wheel in gear with one
of the worms 46 on the shaft 45.
Figure 8 is a vertical section of a third modification in which a rectangular
plunger 49 is made to reciprocate across the bottom of the hopper 28 by a connect-
ing rod and eccentric pin 50 on a worm wheel driven by one of the worms 46. As
the plunger 49 recedes a portion of the fuel falls in front of it and is pushed into
the discharge outlet by the next forward stroke.
My present improved arrangement of the furnace apparatus may be applied to
many of the modifications of boilers described in the earlier Specification herein-
before referred to. Thus in any of such earlier modifications in which a chamber or
space is formed between or within the vertical tubes or equivalent parts and was
formerly used or intended for the actual furnace or fuel grate, I now intend that the
said space shall be used as a combustion chamber for the fire gases, and that the
fuel shall be contained and burned in an external furnace operating as herein-before
described.
Having thus particularly described my said Invention and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original and claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,-
1. The general arrangement or combination of parts constituting the set of com-
pound steam engines herein-before described with reference to Sheet 1 of the accom-
panying Drawings.
2. The placing of the three cylinders so that the piston rods of the outer cylinders
may pass on opposite sides of the crank shaft combined with the attaching of the
three piston rods to one cross head, substantially as herein-before described.
3. The arranging of steam boilers composed principally of small vertical or nearly
vertical tubes combined with larger horizontal tubes or chambers with combustion
spaces for the fire gases between or within the vertical tubes and with external
fire-places and apparatus for supplying air and fuel, all substantially as herein-before
described.
In witness whereof, I, the said Frederick John Rowan, have hereunto set my
hand and seal, this Twelfth day of May, in the year of our Lord One
thousand eight hundred and seventy-seven.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
FRED. JNO. ROWAN. (LS.)