IMPROVEMENTS IN STEAM BOILERS AND IN THE FITTINGS CONNECTED THEREWITH
Year: 1878

page_text: LETTERS PATENT to David Joy, of Barrow-in-Furness, in the County of
Lancaster, for the Invention of "IMPROVEMENTS IN STEAM BOILERS AND IN
THE FITTINGS CONNECTED THEREWITH."
Sealed the 16th August 1878, and dated the 18th February 1878.
PROVISIONAL SPECIFICATION left by the said David Joy at the Office of
the Commissioners of Patents on the 18th February 1878.
DAVID JOY, of Barrow-in-Furness, in the County of Lancaster.
IN STEAM BOILERS AND IN THE FITTINGS CONNECTED THEREWITH."
"
"IMPROVEMENTS
My Invention relates to improvements in the construction and arrangement of
steam boilers or groups of steam boilers, and in their fittings and connections. It
has for its object to allow of high pressures being carried with greater safety and
reduced weights.
According to my Invention in constructing a boiler instead of using the one large
shell containing one or more furnaces with tubes, flame box, and steam space, I
make my boiler or unit of a group of boilers of two or more shells, the lower shell
containing the furnace, flame box, and tubes, which nearly fill it, leaving only room
for cleaning; and in this part of the boiler the generation of steam is carried on.
Above this is a second shell, in which the separation of the steam from the water
which rises into it from the lower shell is carried on by a screen of splashers or
troughs, or by passing through a disc wheel in revolution like a turbine, which may
be arranged either inside the upper shell or outside it; this will effectually separate
the steam from the water. From the lowest and coolest part of this upper shell
the water separated from the steam is passed by a pipe to the lowest and coolest
part of the generating shell (or to any other part, as found most suitable), thereby
causing a constant and vigorous circulation to be set up by the steam generated in
the lower shell, lifting with it much water to the upper shell, which after being
separated will gravitate to the lower shell again to pass upwards again and so round
the circuit. If necessary there may again be another separating shell above that
described.

page_text: For large powers I multiply these units into groups of boilers, and thus by
employing much smaller shells for the units of my boiler I shall be able to carry a
much higher pressure of steam with a thinner plate.
For very high pressures I further reduce the size of the lower shell by leaving no
room to enter it to clean the tubes and furnace which fill up the whole space, but
which are made removeable and are attached to the front plate of the shell, the
back of the latter and the combustion chamber being hemespherical or dished, and
connected by one or more large stays at the back are also easily removeable.
To render such groups of boilers safer, and in all cases to limit the extent of any
accident to the unit in which the accident may take place, I furnish each with an
independant stop valve opening by the steam coming from the boiler, but with its
valve either loose on the spindle usually used to lift it or only slightly attached to it,
and also, by preference, arranged with the exit opening above its topmost position
when open that in case of accident to any part of any unit, causing a backward rush
of steam from the other members of the group, such steam would immediately free
the valve and return it to its seat; thus the failure of any unit of a group would
be limited to itself and not extend as usual to all the members of a set.
The same arrangement modified I apply to boilers made on the water tube plan
by supplying each section or set of tubes of such boilers with an automatic valve (or
valves), this valve in the ordinary working of the boiler would stand open, but in
case of any accident or rupture occuring to any tube or part of a section it would
immediately close by the reverse action of the rush of steam or water from the
adjacent sections, thus, as above, limiting the disablement to the one section in
which the accident occurs.
It will be obvious that the same arrangement of stop valve will be applicable to
all boilers where two or more are worked in conjunction.
And further to increase the safety of boilers under pressure, whether constructed
according to my Invention or otherwise, I use an improved safety valve (or valves),
but instead of weighting the same by a spring in the ordinary manner, which though
permitting relief to the boiler by the lifting of the valve suffers compression and so
increases the load on the said valve, I load the valve (or valves) by the direct
pressure of the steam above them imparted to a small piston of suitable area, or to
a disc or discs of pliable material (or a cushion of the same filled with steam) resting
on a block which transmits the pressure to the valve (the head of the valve may
form the block), the pressures therefore under and above the valve always bearing a
like ratio to each other and not being subject to increase by the lifting of the valve.
At the same time any escape steam accumulating in the valve box above the valvo
will not increase the load on it as it also will press equally on the valve and on the
disc or piston.
To regulate the pressure on the said valve, its area to be weighted and that of the
piston or disc weighting it are made different by, say, one square inch (more or less),
and this difference is weighted or relieved, as the case may be, by a long and very
elastic spring; or the same result may be obtained, though only partially, by employing
in lieu of a valve weighted by a piston or disc a double beat valve, and regulating
by the aforesaid "long and elasic spring" on, the differential area of the two seats
of the valve. To relieve such valve (or valves) instead of applying levers or screw
to raise the valve or spring a small cock or valve is provided for allowing a portion
of the steam to escape from the back of the piston or disc weighting the valve, and
so relieving the valve by reducing the pressure on it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said David Joy in the Great Seal Patent Office on the 16th August 1878.
DAVID JOY, of Barrow-in-Furness, in the County of Lancaster. "IMPROVEMENTS
IN STEAM BOILERS AND IN THE FITTINGS CONNECTED THEREWITH."
My Invention relates to improvements in the construction and arrangement of
steam boilers or groups of steam boilers, and in their fittings and connections. It
has for its object to allow of high pressures being carried with greater safety and
reduced weights.
According to my Invention in constructing a boiler instead of using the one large
shell containing one or more furnaces with tubes, flame box, and steam space, I
make my boiler or unit of a group of boilers of two or more shells, the lower shell
containing the furnace, flame box, and tubes, which nearly fill it, leaving only room
for cleaning; and in this part of the boiler the generation of steam is carried on.
Above this is a second shell in which the separation of steam from the water which
rises into it from the lower shell is carried on by a screen of splashers or troughs,
or by passing through a disc wheel in revolution, like a turbine, which may be
arranged either inside the upper shell or outside it; this will effectually separate
the steam from the water. From the lowest and coolest part of this upper shell the
water separated from the steam is passed by a pipe to the lowest and coolest part of
the generating shell (or to any other part, as found most suitable), thereby causing.
a constant and vigorous circulation to be set up by the steam generated in the lower
shell, and lifting with it much water to the upper shell, which after being separated
will gravitate to the lower shell again, to pass upwards again and so round the
circuit. If necessary there may again be another separating shell above that
described.
For large powers I multiply these units into groups of boilers, and thus by
employing much smaller shells for the units of my boiler I shall be able to carry a
much higher pressure of steam with a thinner plate.
For very high pressures I further reduce the size of the lower shell by leaving no
room to enter it to clean the tubes and furnace which fill up the whole space, but
which are made removeable and are attached to the front plate of the shell, the back
of the latter and the combustion chamber being hemispherical or dished, and con-
nected by one or more large stays at the back are also easily removable.
To render such groups of boilers safer, and in all cases to limit the extent of any
accident to the unit in which the accident may take place, I furnish each with an
independant stop valve opening by the steam coming from the boiler, but with its
valve either loose on the spindle usually used to lift it or only slightly attached to
it, and also, by preference, arranged with the exit opening above its topmost position
when open, that in case of accident to any part of any unit, causing a backward
rush of steam from the other members of the group, such steam would immediately
free the valve and return it to its seat; thus the failure of any unit of a group
would be limited to itself and not extend as usual to all the members of a set.
The same arrangement modified I apply to boilers made on the water tube plan
by supplying each section or set of tubes of such boilers with an automatic valve
(or valves), this valve in the ordinary working of the boiler would stand open, but
in case of any accident or rupture occuring to any tube or part of a section it
would immediately close by the reverse action of the rush of steam or water from
the adjacent sections, thus, as above, limiting the disablement to the one section in
which the accident occurs.
It will be obvious that the same arrangement of stop valve will be applicable to
all boilers where two or more are worked in conjunction.
And further to increase the safety of boilers under pressure, whether constructed
according to my Invention or otherwise, I use an improved safety valve (or valves),
but instead of weighting the same by a spring in the ordinary manner, which,
though permitting relief to the boiler by the lifting of the valve, suffers compression.

page_text: and so increases the load on the said valve, I load the valve (or valves) by the direct
pressure of the steam above them imparted to a small piston of suitable area, or to
a disc of pliable material, resting on a block which transmits the pressure to the
valve (the head of the valve may form this block), the pressures therefore under and
above the valve always bearing a like ratio to each other and not being subject to
increase by the lifting of the valve. At the same time any escape of steam accumu-
lating in the valve box above the valve will not increase the load on it, as it also
will press equally on the valve and on the disc or piston.
To regulate the pressure on the said valve, its area to be weighted and that of the
piston or disc weighting it are made different by, say, one square inch (more or less),
and this difference is weighted or relieved, as the case may be, by a long and very
elastic spring; or the same result may be obtained, though only partially, by
employing in lieu of a valve weighted by a piston or disc a double beat valve, and
regulating by the aforesaid "long and elastic spring" in the differential area of the
two seats of the valve. To relieve such valve (or valves) instead of applying levers
or screw to raise the valve or spring a small cock or valve is provided for allowing
a portion of the steam to escape from the back of the piston or disc weighting the
valve, and so releiving the valve by reducing the pressure on it.
And my Invention will be clearly understood by reference to the accompanying
Drawings, in which,—
Figure 1, Sheet 1, represents a longitudinal section of a unit of a boiler arranged
according to my plan; and Fig. 2, Sheet 1, represents a half cross section of the
same.
The lower shell A of the boiler is shewn nearly filled by the furnace combustion
chamber and tubes, leaving only just room to enter in the usual way for cleaning.
In this part of the boiler the generation of steam is carried on, and it is connected
with the upper shell B, where the separation of steam from the water is carried on
by one or more flanged necks c, c, c. The separation of steam and associated water
is promoted by the two shells thus connected being set at a suitable angle to favour
the rise of the steam towards the upper end of the lower shell, passing thus into
the upper shell by any of the necks c, c, c, which necks are also provided with
removeable elongations d, d, d, and these are surmounted by dished caps e, e, e,
acting as splashers to return the water rising with the steam back to the bottom of
the shell, while the steam by its less gravity rises to the upper part; the returned
water will thus form an accumulation on the bottom of the upper shell B, and will
gravitate naturally to the lower end, forming a head of water, which will find its
way back to the lower part of the generating shell by the pipe or pipes p. Thus
in proportion to the energy of the evaporation the amount of water carried into the
shell B will be increased, and so the head of water in that shell tending to produce
circulation back to the lower shell, and so on round again. This effect again may
be increased if desirable by raising the shell B to a greater height above A, and so
increasing the elevation of the head of water. Thus the tendency of the boiler to
give off water from the evaporating surface is utilized to increase circulation by
making it furnish a head of water which will continually force itself into the
lowest part of the boiler. The elongated portions d, d, d, of the necks being light
and removeable allow of the necks themselves being used to inspect and clean the
upper part of the generating portion of the boiler.
Any number of such boilers or units may be connected to one common steam
drum D by a stop valve C, to be hereafter described.
Figs. 3 and 4, Sheet 1, represent longitudinal section and cross section of two t
similar boilers or units placed in a group, only that in the generating shell of these
boilers the furnace combustion chamber and tubes are made to fill the whole of the
shell without leaving room to enter for cleaning; but they are all made removeable
with the front plate by a joint at h, h, which is faced and bolted or otherwise made
secure, at the same time the back of the combustion chamber and the back of the 5
shell, which are both made dished or rounded by preference, or connected by
one or more large bolts or stays made easily removeable.

page_text: The stop valve for connecting the units just described to the common steam
drum or pipe is shewn at Fig. 6, Sheet No. 2, and is very similar to the ordinary
stop valve, with the pressure from the boiler it serves below it. The valve itself i is
sunk so far within the case that when fully opened for the passage of steam it will
still be below the level of the outlet for the steam; this valve is also fastened to
the spindle by a pin of lead or other soft material, or in other loose method, as
by friction only, or it may be quite loose. Thus if any boiler or unit of a group of
boilers so connected should fail, the rush of steam towards this boiler or unit would
release (by the backward pressure on it) the valve from the spindle, and would
return it to its seat, so stopping all escape of steam or water from the other units
of the group and limiting the result of the failure to the one only.
In the same way I treat each section of a water tube boiler, such as is shewn in
Fig. 5 of Sheet No. 1. In these boilers I place a similar self-closing valve at the
water supply end of each section of tubes j, Fig. 5, and at Fig. 7, Sheet No. 2. And
at the steam outlet I also place a suitable non-return valve k, by preference similar
to that shewn in detail at Fig. 8, Sheet No. 2. Both of these are free to return
upon their respective outlets in case of an accident happening in the section to
which they belong, thus isolating that section and preventing the outflow through
it of the water and steam from the other sections of the boiler.
And for the safety valves of such boilers I employ a valve or valves, as shewn
at Figs. 9 and 10, Sheet No. 2, such valve or valves being partially weighted by
the steam from the boiler acting on an elastic disc or diaphragm o, or on and
between several discs or diaphragms connected at their edges, so forming an elastic
cushion, as shown at n, the pressure so obtained is transmitted either directly to
the valve or through a short cross bar or lever p. When two or more valves are
employed this pressure on the diaphragm or cushion does not however exactly
balance that under the valves to be weighted, as the diaphragm or cushion is made
of a somewhat smaller area than the area of the valve or valves, but the balance of
pressure required is made up by the application of a spring r, as shown in Figs. 9
and 10, which may be adjusted to the pressure required by the screw 8, on to which
the locking plate tis then placed and locked, to prevent alteration by the attendant.
Or the adjustment of the balance may be reversed, and the diaphragm or cushion
may be made of greater area than the valve or valves, and the spring will then
have to act by relieving the valves, thus reversing the arrangement just described.
And for relieving the pressure on the safety valves so weighted I employ in the
pipe or channel conveying the steam to the diaphragm or cushion a small valve or
cock u to let off some of the steam, reducing the pressure thereon, and so lightening
that pressure and permitting the valves to rise and so blow off the steam.
Having now described my Invention, and the method of carrying it out, I
claim, improvements in the construction and arrangement of steam boilers and in
the fittings therefor, substantially as herein-before described, and illustrated by
the accompanying Drawings.
In witness whereof, I, the said David Joy, have hereunto set my hand
and seal, this Nineteenth day of July, in the year of our Lord One
thousand eight hundred and seventy-eight.
DAVID JOY. (L.S.)