IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1860

page_text: ETTERS PATENT to Robert Bell, of 24, Elswick West Terrace, New-
castle-upon-Tyne,in the County of Northumberland, Engineer, Adrainis-
trator of the Estate and Effects of John Smith Bell, late of the Town and
County of Newcastle-upon-Tyne, Engineer, who departed this life at the
Bridge of Allan, in the County of Stirling, North Britain, on the Twenty-
ninth day of June, One thousand eight hundred and sixty, for the
Invention of "IMPROVEMENTS IN STEAM ENGINES AND BOILERS."
PROVISIONAL SPECIFICATION left by the said John Smith Bell at
the Office of the Commissioners of Patents, with his Petition, on the
22nd March 1860.
I, JOHN SMITH BELL, of the Town and County of Newcastle-upon-Tyne,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN STEAM ENGINES AND BOILERS," to be as follows:-
This Invention relates to certain peculiar constructions and arrangements
of marine and other steam engines and boilers, and consists, as regards that
part of my Invention which relates to steam engines, in placing a small high-
pressure cylinder concentrically within a large low-pressure cylinder, and
working the two pistons in opposite directions, so that they may partially or
wholly counterbalance each other, and thereby prevent any great inequality
of strain upon the working parts, whilst at the same time a simple and
[Price 8d.1

page_text: economical mode of working high-pressure steam is obtained. The piston
of the high-pressure cylinder may be of the ordinary construction, with one
or more rods and connecting rods attached to a central crank on the main
shaft but the piston of the low-pressure cylinder is of an annular form and
is attached by two piston rods and connecting rods to two cranks placed
one on each side of the crank for the high-pressure cylinder and in a position
diametrically opposite to it, when two or more pairs of cylinders are used,
but when only one pair of cylinders is employed the relative cranks of the
high and low-pressure cylinders may be at an angle of about 178° or less
with each other, by which arrangement the engine will be more easily
started as the dead centres will be avoided. It is proposed to employ only
one slide valve to each pair of cylinders for admitting the steam to the
high-pressure cylinder transmitting it to the low-pressure cylinder, and
conducting it thence to the condenser, though the same may be effected
by two or more slide valves in the usual way.
According to my improved valvular arrangement, I propose to make the
steam ports of the high-pressure cylinder only one-half the width of the steam
ports of the low-pressure cylinder, consequently the steam passages can be
made through the main slide valve, and still allow of sufficient room on each side
of such passage for the steam to pass when exhausting from the high-pressure
cylinder to the steam side of the low-pressure piston. Expansion slides are
fitted to work on the back of the main slide, and are connected at the ends
by rods passing on each side of the main slide, both rods being secured to a
cross head, and worked by one eccentric and link, or by any other suitable
valve motion. It is further proposed to pass a quantity of the injection
water of the condenser through a refrigerator, which may be constructed in
the form of any of the surface condensers at present in use, the injection
water being passed through the tubes or other passages in lieu of the steam.
The water thus cooled in the refrigerator is returned to the condenser again
to be re-employed. A portion of the water equal to the steam condensed
is taken at each stroke from the injection water before it passes into the
refrigerator, and returned to the boiler by feed pumps. When using fresh
water in the boiler the loss by leakage may be replaced by a small distilling
apparatus. By these arrangements saturation or an undue degree of salt-
ness in sea water when used in marine boilers is prevented, or fresh or
distilled water may be used in them.
My improvements in marine boilers consist in making their backs, tops,and
fronts (above the smoke box) of a semicircular or curved form, whereby
greater strength is obtained, and many of the stays at present required are

page_text: dispensed with. The interior of the boiler and its furnaces is so arranged
that the flame or heated gases after passing from the furnaces to the back
of the boiler, return between rows of vertical tubes filled with water to the
front, and then pass through another series of vertical tubes, the lower ends
of which are covered with water, and the upper portions passing through
steam, so that the latter will become to a certain extent superheated.
SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said Robert Bell in
the Great Seal Patent Office on the 22nd October 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
BELL, of 24, Elswick West Terrace, Newcastle-upon-Tyne, in the County of
Northumberland, Engineer, Administrator of the Estate and Effects of John
Smith Bell,late of the Town and County of Newcastle-upon-Tyne, Engineer,
who departed this life at the Bridge of Allan, in the County of Stirling,
North Britain, on the Twenty-ninth day of June, One thousand eight
hundred and sixty, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of March, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
the said John Smith Bell, Her special license that he, the said
John Smith Bell, his executors, administrators, and assigns, or such
others as he, the said John Smith Bell, his 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 ENGINES," upon the condition (amongst others)
that he the said John Smith Bell, his executors or administrators, by an
instrument in writing under his, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office on or before the Twenty-second
of October, One thousand eight hundred and sixty.
NOW KNOW YE, that I, the. said Robert Bell, as such Administrator
as aforesaid, do hereby declare the nature of the said Invention, and in what

page_text: manner the same is to be performed, to be particularly described and ascer-
tained 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:-
The said Invention relates to certain peculiar constructions and arrange-
ments of marine and other steam engines and boilers, and consists, as regards
that part of my Invention which relates to steam engines, in placing a small
high-pressure cylinder concentrically within a large low-pressure cylinder, and
working the two pistons in opposite directions, so that they may partially or
wholly counterbalance each other, and thereby prevent any great inequality
of strain upon the working parts, whilst at the same time a simple and
economical mode of working high-pressure steam is obtained.
The piston of the high-pressure cylinder may be of the ordinary construction,
with one or more rods and connecting rods attached to a central crank on the
main shaft, but the piston of the low-pressure cylinder is of an annular form,
and is attached by two piston rods and connecting rods to two cranks placed
one on each side of the crank for the high-pressure cylinder, and in a position
diametrically opposite to it, when two or more pairs of cylinders are used, but
when only one pair of cylinders is employed the relative cranks of the high
and low-pressure cylinders may be at an angle of about 178° or less with each
other, by which arrangement the engine will be more easily started, as the
dead centres will be avoided. It is proposed to employ only one slide valve
to each pair of cylinders for admitting the steam to the high-pressure cylinder,
transmitting it to the low-pressure cylinder, and conducting it thence to the
condenser, though the same may be effected by two or more slide valves in
the usual way. According to this improved valvular arrangement, I propose
to make the steam ports of the high-pressure cylinder only one-half the width
of the steam ports of the low-pressure cylinder, consequently the steam
passages can be made through the main slide valve, and still allow of sufficient
room on each side of such passage for the steam to pass when exhausting from
the high-pressure cylinder to the steam side of the low-pressure piston.
Expansion slides are fitted to work on the back of the main slide, and are
connected at the ends by rods passing on each side of the main slide, both
rods being secured to a cross head and worked by one eccentric and link, or
by any other suitable valve motion. It is further proposed to pass a quantity
of the injection water of the condenser through a refrigerator, which may be
constructed in the form of any of the surface condensers at present in use, the
injection water being passed through the tubes or other passages in lieu of
the steam. The water thus cooled in the refrigerator is returned to the

page_text: condenser again to be re-employed. A portion of the water equal to the
steam condensed is taken at each stroke from the injection water before it
passes into the refrigerator, and returned to the boiler by feed pumps.
When using fresh water in the boiler, the loss by leakage may be replaced
by a small distilling apparatus. By these arrangements saturation, or an
undue degree of saltness in sea water when used in marine boilers, is
prevented, or fresh or distilled water may be used in them.
The improvements in marine boilers consist in making their backs, tops,
and fronts (above the smoke box) of a semicircular or curved form, whereby
greater strength is obtained, and many of the stays at present required
are dispensed with.
The interior of the boiler, with its furnace, is so arranged that the flame
or heated gases, after passing from the furnaces to the back of the boiler,
return between rows of vertical tubes, filled with water to the front, and
then pass through another series of vertical tubes, the lower ends of which
are covered with water, and the upper portions passing through steam, so
that the latter will become to a certain extent superheated.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
Figures.
Figure 1 of the Drawings represents a longitudinal vertical section of my
improved combined high and low-pressure steam engine as capable for driving
a screw propeller shaft, the cylinders being inverted. A is a small high-
pressure cylinder, placed concentrically within the large low-pressure cylinder
B, the respective pistons of the two cylinders being made to travel in opposite
directions by placing their relative cranks C and D, D, on diametrically
opposite sides of the crank shaft E, as shewn in the Drawings, by which
arrangement the two pistons will wholly or partially counterbalance each
other, and consequently any irregularity in the strain upon the working
parts of the engine is obviated. The piston F of the high-pressure cylinder
may be of the ordinary construction, provided with one or more piston rods G
and connecting rods H, attached to the central crank C. The piston I of the
low-pressure cylinder B is of an annular form, being packed to work steam-
tight against the exterior of the high-pressure cylinder and the interior of
the low-pressure cylinder; it is attached to two piston rods K, K, which
are connected by suitable connecting rods, not shewn in the Drawings, to
the two cranks D, D, respectively. When two or more pairs of cylinders

page_text: are used, I propose to make the cranks of the high and low-pressure cylinder
in each pair diametrically opposite to one another, as above stated, but when
only one pair of cylinders is used, I prefer to place the respective cranks at
an angle of about 178° or less with each other, in order to prevent the
pistons and connecting rods of the two cylinders ever being in a direct line
with the centre of the crank shaft at the same time, whereby the starting of
the engine is greatly facilitated.
a, a,
I propose to employ a peculiarly constructed slide valve for distributing the
steam entirely by the aid of one single slide valve. I am enabled to admit
the steam to the high-pressure cylinder,transmit it thence to the low-pressure
cylinder, and finally from the low-pressure cylinder to the condenser.
are the steam ports of the high-pressure cylinder, which are only one-half the
width of the ports b, b, of the low-pressure cylinder; L, L, is the main slide
valve, in the interior of which are formed the steam passages c, c, sufficient
space being left at d, d, round such passages for the free exhaust of the steam,
as will be clearly seen on reference to Figure 2, which is a sectional elevation
of the valves full open; the high-pressure steam is here shewn as entering the
upper end of the high-pressure cylinder, and exhausting into the lower end of
the low-pressure cylinder, whilst the final exhaust of the steam from the upper
part of the low-pressure cylinder is simultaneously taking place through the
exhaust passage e. In Figure 1 the slide valve is shewn at half stroke, the
steam and exhaust parts being all closed. M, M, are the expansion slides
working on the back of the main slide, and worked by two rods passing one on
each side of the main slide valve rod, and connected by a cross head, and
which is worked from one eccentric and link or other valve motion, which I
have not considered it necessary to illustrate by Drawings. Figure 3 repre-
sents an end elevation and partial transverse section of my improved form of
steam boiler; Figure 4 is a longitudinal vertical section of the same; and
Figure 5 is a corresponding sectional plan of the boiler. The shell of this boiler
is made semicircular or of a curved form at the back, front, and top, as shewn
at A, B, and C, respectively; these semicircular sections are connected to each
other by angle iron, as shewn at a, u. By making the surfaces of the boiler
semicircular or curved in lieu of flat, greater strength is obtained and fewer
stays required. D is the furnace chamber, the fire-bars of which are not
shewn in the Drawings, and E, E, are a number of vertical water tubes placed
in the flue F, and opening into the body of the boiler above or below that flue
so as to produce a free circulation of the water in the boiler. The flames and
gases after playing round these tubes enter the series of vertical tubes G. G,
through which they pass to the chimney. As these tubes G are only sur-

page_text: rounded with water at their lower ends, whilst the greater portion of their
length is contained in the steam space of the boiler, it follows that a
considerable degree of heat will be imparted to the steam, which thereby
becomes to a certain extent superheated in the boiler.
Having now described and particularly ascertained the nature of the 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
herein-before in part recited Letters Patent is,-
1st, the general construction and arrangement of steam engines and
boilers, as herein-before described.
2nd, the application and use of high and low-pressure cylinders arranged
concentrically in combination with cranks set diametrically or nearly
diametrically opposite to each other, as herein-before described.
3rd, the peculiar construction and arrangement of slide valves for high
and low-pressure cylinders, as herein-before described.
4th, the constructing of steam boilers or generators with semicircular or
curved backs, tops, and fronts, as herein-before described.
5th, the peculiar arrangement of tubes in the interior of steam boilers
or generators, whereby the superheating or drying of the steam in such
boilers may be effected simultaneously with the generation of the steam,
as herein-before described.
In witness whereof, I, the said Robert Bell, as such Administrator as
aforesaid, have hereunto set my hand and seal, the Eighteenth day
of October, One thousand eight hundred and sixty.
ROBERT BELL. (1.8.)