IMPROVEMENTS IN STEAM BOILERS AND IN APPARATUS CONNECTED THEREWITH.
Year: 1876

page_text: LETTERS PATENT to Thomas Black, of Liverpool, in the County of Lancaster,
but at present residing at Glasgow, in the County of Lanark, North Britain,
for the Invention of "IMPROVEMENTS IN STEAM BOILERS AND IN APPARATUS
CONNECTED THEREWITH.
"
PROVISIONAL SPECIFICATION left by the said Thomas Black at the Office
of the Commissioners of Patents on the 19th April 1876.
THOMAS BLACK, of Liverpool, in the County of Lancaster, but at present residing
at Glasgow, in the County of Lanark, North Britain. "IMPROVEMENTS IN STEAM
BOILERS AND IN APPARATUS CONNECTED THEREWITH."
The improvements constituting this Invention relate in the first place to that
class of boilers in which two or more are grouped together with a flue or uptake
between them, and by which the cost and construction of such boilers is greatly
simplified. The boilers communicate with one another at the bottom by means of
a water space, and the heated gases and products of combustion pass from each fire-
grate into the lower part of the uptake to the smoke box at the front of each boiler,
from which they return through a flue or flues to the upper part of the uptake,
and then through a steam chest common to both boilers.
The uptake between the boilers is divided into upper and lower portions by
means of a water space, or a series of large tubes or passages at a level situato
between the rows of tubes and the upper return flues. This upper water space or
tubes and the lower water space are connected together by a vertical circulating
passage, and this or these again is or are connected to the feed water and circulating
tubes which pass through the fire-box. The circulating tubes are provided with
removable covers to enable them to be cleaned from time to time, and in the steam
chest one side or portion is partitioned off into which the steam enters from the
top of the steam chest, and being led off for use through the lower part thereof
constitutes a superheater.
In the case of a single boiler of the class herein-before mentioned, constructed
according to these improvements, the uptake, berein-before described, is dispensed
with, and the products of combustion and heated gases escape into the steam chest
through one or more flues leading out of the return flue.

page_text: In the case of a horizontal boiler the feed water pipes are led directly through
the fire-box and flue, so that the feed water as it is forced in becomes at once
heated and enters the boiler at, the rear end above the flue, the feed pipe or pipes
being provided with an upturned end for that purpose.
The improvements in boiler safety valves consist as follows: -The valve itself
consists of two portions, viz., an upper and lower valve, the upper being the safety
valve proper, the lower being in the form of a plug valve fitting its guide or
enclosure so closely as to admit of but a very small escape of steam. These valves
are connected together and maintained at a fixed distance apart by means of a
spindle. The seat of each valve, namely, the upper and lower one is situate in a
chamber common to both valves, and the area of the lower valve is greater than
that of the upper valve.
The chamber which contains the valves is connected by a passage directly with
the steam space of the boiler, so that the steam acts directly with its full pressure
upon the upper valve and keeps both valves shut. Between the boiler and that
part of the chamber which contains the lower valve there is a communicating
passage, in which is a relief valve loaded to the pressure at which it is desired the
safety valves should allow steam to blow off. So long as the pressure in the boiler
is below the blowing-off pressure the relief valve remains shut and communication
through the passage is closed, but the instant that the blowing-off pressure is
reached the relief valve is opened and the steam at once has access to the under
side of the lower or easing valve, which, as herein-before mentioned, being of larger
area than the upper valve at once lifts it wide open, and thereby ensures the boiler
being instantly and fully relieved of any preponderance of pressure.
In case it is desired at any time to open the safety valve when the pressure in
the boiler is below that at which the relief valve is loaded, a cock is provided for
the purpose of turning steam directly in from the boiler to the under side of the
lower or easing valve.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Black in the Great Seal Patent Office on the 19th October
1876.
THOMAS BLACK, of Liverpool, in the County of Lancaster, but at present residing
at Glasgow, in the County of Lanark, North Britain. "IMPROVEMENTS IN STEAM
BOILERS AND IN APPARATUS CONNECTED THEREWITH."
The improvements constituting my said Invention relate in the first place to that
class of boilers in which two or more are grouped together with a flue or uptake
between them, and by which the cost of such boilers is diminished, and their con-
struction simplified.
The boilers communicate with one another by means of a waterspace, and
the heated gases and products of combustion pass from each fire-grate into the
lower part of the uptake or combustion chamber, and thence into the smoke box
at the front of each boiler, from which they return through a flue or flues to the
upper part of the uptake, and then through a. flue which is surrounded by a steam
chest common to both boilers.
The Invention also relates to boilers otherwise constructed and to improved safety
valves for the same, which valves may also be used in other situations, such as on
water mains.
And in order that my said Invention may be properly understood I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, reference being had to the
annexed Sheets of Drawings and to the letters and figures marked thereon, that is
to say-

page_text: On Sheet 1 of the Drawings hereunto appended Figure 1 is a vertical section of
two boilers grouped in the manner herein-before set forth, and connected together
in accordance with the improvements constituting my said Invention; Figure 2 is a
transverse section on the line a, b, passing through the uptake or combustion
chamber between the two boilers; whilst Figure 3 is a horizontal section of the
boilers on the line c, d, Figure 1. As seen by these Figures the boilers A and B
communicate with each other at the bottom by means of a water space C, and the
products of combustion pass from the fire-grates D in each boiler into the uptake E
situated between them. The uptake is divided into an upper and lower portion by
the water space or channel F extending across it and communicating with both
boilers A and B, or it may be so divided by a series of tubes. From the lower part
of the uptake the products of combustion pass through tubes G into the smoke
boxes at the fronts of the boilers, from which they return through the flues I
into the part of the uptake above the water space or channel F, and thereafter pass
off through the flue J, which is surrounded by the steam chest K, at whose interior
a portion is divided off, as seen in detail at L, Figure 4, Sheet 1, so as to form a
superheater, into which the steam passes from the upper end of the chest K. The
steam in thus passing through the chamber L to the exit a thereof (Figure 2) is
superheated by the heat given off from the waste products of combustion as they
pass off through the flue J.
The water space or channel F is connected to the water space C communicating
with the bottoin part of each boiler by a vertical circulating passage M, on which
branches or arms N are made, as seen at Figures 2 and 3, Sheet 1. Circulating
tubes O, passing through the fire-boxes D, communicate at their inner ends with
the branches or arms N, and at their outer ends with chambers P. The feed water
is conducted into these chambers, and therefrom circulating through the pipes O, is
heated before being discharged into the water spaces of the boilers by the vertical
passage M.
The chambers P communicate with the water space C, common to
both boilers by the side passages R, and each such chamber also communicates with
the water space surrounding the fire-boxes D of its own boiler by a central passage S.
By this means a circulation of water through both boilers is promoted in the direction
of the arrows, Figures 1, 2, and 3, Sheet 1, that is to say, through the pipes O and
passage M, whereby the water is prevented from remaining dormant at the bottom
of the boiler, and is exposed to a greater amount of heating surface than in such
boilers as ordinarily constructed.
Under a modification of the improvements herein-before described the vertical
circulating passage M, instead of being formed with branches or arms thereon, as
seen at Figures 1, 2, and 3, Sheet 1 of the Drawings, is made without such branches
or arms, as illustrated at Figures 5, 6, and 7 on the said Sheet, Figure 5 being a
vertical section; Figure 6, a transverse section on the line e, f, Figure 5; and
Figure 7, a horizontal section on the line g, h, Figure 5, of the boilers A and B, with
the passage M so constructed. With this arrangement the circulating pipes O are
at their inner ends bent upwards, and connected direct to the water space or channel
F, communicating between the boilers at their upper parts.
The circulating tubes both in this arrangement and in the arrangement herein-
before referred to are provided with removable covers to enable them to be cleaned
from time to time.
The improvements herein-before described may also be applied to boilers of the
class set forth in cases where more than two of such boilers are grouped together,
or as seen in vertical section at Figure 1, and in part transverse section and part
end elevation at Figure 2, Sheet 2, of the Drawings; they may be applied to a
single boiler.
In this case the uptake herein-before referred to is partly dispensed
with, and the products of combustion and heated gases escape from the smoke box
A by return flues B leading direct to the flue C passing through the steam chest D.
Figure 2a is a horizontal section of the steam chest and superheater E.
Figure 3, Sheet 2, illustrates in longitudinal section, Figure 4 in horizontal
section, Figure 5 in end clevation, and Figure 6 in transverse section on the line

page_text: a, b, Figure 3, the adaptation of the improvements herein before described to a
horizontal boiler. In this case the feed water circolating pipes A, of which any
desired number may be employed, are led from the chamber B at the frout of the
boiler directly through the fire-box C and flue D, so that the feed water as it is
forced in becomes at once heated, and enters the boiler at the rear end above the
flue, the circulating or feed pipes being bent upwards for that purpose, as seen on
the Drawings. The water also circulates from the water space of the boiler into
and through the pipes A, being conducted thereto through the side chambers or
passages E, as indicated by the arrows. By this arrangement not only is the feed
water highly heated before entering the boiler, but the water, which in ordinary
constructions of boilers remains dormant at the bottom, is in this case kept moving
continually and with rapidity from one point to another along the heating surface,
thus adding to the generating powers of the boiler and effecting economy of fuel
therein.
The improvements in steam boiler safety valves embraced by this Invention may
be described as the steam loaded safety valve embodying three distinct valves
(marked on sectional Drawing Sheet 2, Figure 7), I, B, and A. The small relief
valve I being the first and principal seat of motion, regulates, controls, and operates
the valves Band A, which are illustrated under one modification by the vertical
section Figure 7, Sheet 2, of the appended Drawings, and as shewn thereby the
valve itself consists of two portions, viz., an upper valve A and a lower one B,
these being connected together and maintained at a fixed distance apart by a
spindle C. A small space is or may be left between the collar m on the spindle
and the top of the valve B to permit of expansion of the latter.
The hollow part D of the upper valve, and also the similar part of the lower
valve, are preferably filled with load, block tin, or equivalent material to give
stability.
The upper valve A is the safety valve proper, the lower one B, which is a plug
valve, being packed in its guide or enclosure by means of the packing rings a.
These rings are made so to fit the guide or enclosure as just to fill the orifice
without causing frictional contact or liability to jamb through expansion or from
the entrance of sand or grit, and they are cut through at one side and sprung into
countersunk checks made to receive them in the valve B. By so cutting the
rings a when friction or strain comes upon them they yield inwards and allow the
valve B, which is fitted loosely in its enclosure as shewn, to rise or fall freely. The
seats of the valves A and B are situated in a chamber F common to both valves,
and the area of the lower valve B is greater than that of the valve A.
The chamber F is connected by a passage G with the steam space of the boiler so
that the steam acts directly with its full pressure upon the top of the valve A and
keeps both valves shut; between the boiler and the lower part of the chamber Fa
communication H is made, and in connexion therewith a relief valve I is so situated
that the steam must act thereon before entering the said chamber F; this valve,
constructed as shewn on the Drawings, is loaded by weights J to the pressure at
which it is desired the safety valve should allow the steam to blow off. The steam
on passing through the valve I enters the chamber F by the communication H,
where it acts on the under side of the easing valve B. This valve being of larger
area than the safety valve A at once lifts the said valve wide open and thereby
ensures the boiler being instantly and fully relieved of any preponderance of
pressure above that of the weights J, which being effected the said weights close
the relief valve I and shut off communication between the boiler and the valve B.
A pipe M also communicates with the lower part of the chamber F and with the
atmosphere, and in the said pipe a three-way cock is placed whereby communica-
tion may be effected between the pipe and the boiler when required. This com-
munication is so made when it is desired to blow off steam, and the steam passing
through the pipe M into the chamber raises the valves B and A, thereby allowing
steam from the boiler to escape by the latter valve through the blow-off orifice N
and pipe attached thereto. When it is required to shut the safety valve A the

page_text: cock is closed to the boiler and opened to the atmosphere so that the pipe M may
act as a drain pipe and prevent steam and water from collecting in the chamber F.
The cock on the front of the boiler is useful as enabling the engineer to try the
valves at any moment and thereby assure himself that they are in proper working
order; but it is in some cases, as, for example, in the case of marine or locomotive
boilers, preferred to employ in addition to the said cock the ordinary arrangement O
of lever attached to the spindle of the safety valve in order to allow the steam to
pass off gently from the boiler. The hand steam easing gear opens the safety valve
instantaneously and allows the steain to escape very quickly.
Instead of weighting the relief valve I in the manner set forth it may be weighted
by a spring, as seen at Figure 8, Sheet 2. The spring which is held down by a
screwed clamp or cover S, either in the manner shewn at Figure 8, Sheet 2, or in
the manner herein-after described, fits into the same position as that occupied by
the weights J, Figure 7, Sheet 2, and both it and the weights are so arranged that
the one mode of exerting the pressure may with facility be substituted for the
other when desired.
The Figures on Sheet 3 of the Drawings shew several arrangements of the steam
loaded safety valve herein-before described as adapted for employment on marine
boilers.
Figure 1, Sheet 3, is a vertical section, and Figure 2 a horizontal section on the
line a, b, Figure 1, of a group of four safety valves A, B, C, and D, operated by two
relief valves E, F, constructed as herein-before described with reference to Figure 7,
Sheet 2. One of these relief valves (the valve E) is intended to act as a government
or lock up valve, and the other (the valve F) as an engineer's or open valve. In
this case the four valves are represented as connected to one boiler by the passage G,
which arrangement may be adopted when the boiler is of large capacity or
generating power, or where it is necessary to have valves of small area.
When not all connected to one boiler, and when four or more steam-loaded safety
valves are grouped and operated in the manner above referred to, the steam in lieu
of passing to the valves through the channel G may be conducted from the different
boilers to each two or more valves constituting one set by pipes connected to the
valve chest at P, Figure 2, Sheet 3.
Figure 3, Sheet 3, is a part front elevation, Figure 4 a side elevation, Figure 5
a part horizontal section and part plan, and Figure 6 a complete plan of another
arrangement of the steam-loaded safety valve as adapted for marine purposes.
Under this arrangement two safety valves A and B are used, each being provided
with a relief valve, one of which, the valve C, constitutes a government or lock-up
valve, and the other D an engineer's or open valve.
Figure 7, Sheet 3, is a vertical section, Figure 8 a part horizontal section and
part plan, and Figure 11 a section at right angles to Figure 7 of an arrangement of
the improved steam-loaded safety valve wherein two relief valves A and B act upon
the same casing valve C.. One of these relief valves acts as a government or lock-
up valve, and the other as an engineer's or open valve, and together with the relief
valves illustrated by the other Figures on this Sheet they may be loaded by
weights E, as seen at Figure 7, or they may be loaded. by a spring, as seen in
vertical section at X, Figure 9, Sheet 3. The spring is held in position by a cap W,
seen in plan at Figure 10, which is or may be secured by bolts a, as shewn, or by
forming it with a screw thread, as seen at Figure 8, Sheet 2 of the Drawings.
The improved safety valves besides being employed for the purpose herein-before
described may also be used in situations generally wherein such valves are
employed; for example, they may with advantage be fitted in connexion with
hydraulic, gas, or other pressure mains, in which case the pressure on the safety
valve proper is exerted by the pressure of the liquid or fluid passing through the
mains, the relief and easing valves being also similarly operated by the excess of
pressure in the said mains above the desired limit.
Having now described and particularly ascertained the nature of my said
Invention, and the system, mode, or manner in or under which the same is or may

page_text: be used or practically 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 herein-before in part recited Letters Patent is,―
First. The improved feed water heating and water circulating apparatus herein-
before described with reference to Figures 1, 2, and 3, Sheet 1, of the Drawings,
consisting of the channels F and M, pipes O, chambers P, and passages R, S, and
the employment of the same in boilers of the class wherein two or more are grouped
together with an uptake or combustion chamber between them, substantially as
set forth.
Second. The improved feed water heating and water circulating apparatus
herein-before described with reference to Figures 5, 6, and 7, Sheet 1, of the
Drawings and the employment of the same, as and for the purposes set forth.
Third. The boiler herein-before described and shewn at Figures 1 and 2, Sheet 2,
of the appended Drawings with feed water heating and water circulating apparatus,
arranged substantially in the manner set forth.
Fourth. The horizontal boiler herein before described and shewn at Figures 3, 4,
5, and 6, Sheet 2, of the Drawings, with feed water heating and water circulating
apparatus, arranged therein, substantially in the manner set, forth.
Fifth. The improved safety valve herein-before described and shewn under
several arrangements at Figures 7 and 8, Sheet 2, and by the Figures on Sheet 3 of
the Drawings, wherein easing and relief valves are used substantially in the manner
described in conjunction with a safety valve proper which is loaded by the pressure
of steam within the boiler, or by the pressure within any other apparatus whereon
the valve is fitted.
Sixth. The combined safety valve and casing valve, constructed substantially as
described.
Seventh. The packing rings a in conjunction with the casing valve, whereby the
said valve is prevented from jambing from expansion or from the entrance of sand
or grit into its guide or enclosure, substantially as set forth with reference to
Figure 7, Sheet 2, of the appended Drawings.
In witness whereof, I, the said Thomas Black, have hereunto set my hand
and seal, this Eighteenth day of October, One thousand eight hundred and
seventy-six.
THOMAS BLACK. (L.S.)