IMPROVEMENTS IN STEAM BOILERS AND IN APPLIANCES CONNECTED THEREWITH, A PART OF WHICH APPLIANCES IS APPLICABLE TO ENGINES
Year: 1877

page_text: LETTERS PATENT to William Rowan, of 96, York St, Belfast, in the County
of Antrim, Engineer, for the Invention of "IMPROVEMENTS IN STEAM BOILERS
AND IN APPLIANCES CONNECTED THEREWITH, A PART OF WHICH APPLIANCES
IS APPLICABLE TO ENGINES"
Sealed the 20th July 1877, and dated the 24th January 1877.
PROVISIONAL SPECIFICATION left by the said William Rowan at the Office
of the Commissioners of Patents on the 24th January 1877
WILLIAM ROWAN, of 96, York St, Belfast, in the County of Antrin, Engineer
"IMPROVEMENTS IN STEAM BOILERS AND IN APPLIANCES CONNECTED THEREWITH, A
PART OF WHICH APPLIANCES IS APPLICABLE TO ENGINES"
My improvements consist in the arrangement of flues and tubes, and the general
construction of steam boilers known as the Cornish or Lancashire description, in
which there are two fine-boxes of the usual cylindrical form At the end of the
fire-boxes beyond the bridge the flues become flat on one side like the letter D with
the flat sides facing each other, and parallel from the end of the fire-box to the back
end of the boiler The D formed flues nic connected together by transverse tubes,
and divided into three or more sections or series of tubes, as the following description
will explain
When the smoke and gases are emitted from the fire-box they pass into the
flue No 1, and in the passage are called along to a water partition or stop
which is placed across the flues, therefore the smoke and gases traverse the first
section of tubes when they enter flue No 2, where they intermix with the smoke
and gases from No 2 furnace, then they pass along the flue to the water partition,
or stop when the smoke and gases traverse the second section of tubes into
flue No 1 The smoke and gases pass along this flue to the second water partition
or stop, and traverse the third section into flue No 2 The smoke and gases then
pass along this fluc to the water partition or stop at the back end plate of the
boiler when they traverse the fourth section into flue No. 1, along which the smoke
and gases pass through the back end plate of the boiler into the flue leading to the
chimney.

page_text: I utilize the waste heat after leaving the boiler by an arrangement of pipes
in the flue to the chimney. The heated air I conduct through a pipe to the back of
the fire-bridges where it mixes with and will tend in a great measure to consume
the smoke, or the smoke and gases may be carried around the outside of the
boiler in brick flues, the usual mode that boilers are set before entering the
chimney
The water partitions or stops that are placed in the flues act and are an
important element in my improvements, because they divert the smoke and gases
through the tubes and admit of expansion and contraction in the fire-boxes and
flues
My improvements can be casily arranged for water tubes if desirable, also my
improvements are equally applicable to upright as they are to horizontal boilers
·
Further, in connection with my improvements in steam boilers I purpose to
introduce what I term a safety alaim disc This is an appendage fitted on any
convenient part of the steam room of the boilet, I prefer the front end plate There
18 a saddle rivetted on the boiler of say, 4 or 5 inches diameter with a flange on
the top side of the saddle Over this flange I place a disc of copper or other metal
which is enclosed by a dome-formed cover between the flanges of the saddle and the
dome cover
this copper disc is bolted steam-tight between the flanges. The disc is
made of such strength that it will burst at 5 lbs or so above the working pressure
of the boiler, through which a rush of steam would escape by an aperture in tho
clown of the dome, consequently giving unmistakeable alarm to the engineer or
those in charge that the pressure is 5 lbs in excess of what it should be, inti-
mating that the safety valve is not in order This safety disc is also applicable
to cylinders of steam engines as a preventive in case of accident to the engine fron
priming or condensation of the boilers
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Rowan in the Great Seal Patent Office on the 24th July
1877
WILLIAM ROWAN, of 96, York Street, Belfast, in the County of Antrim, Engineer
"IMPROVEMENTS IN STEAM BOILERS AND IN APPLIANCES CONNECTED THEREWITH, A
PART OF WHICH APPLIANCES IS APPLICABLE TO ENGINES"
My improvement consists in the arrangement of flues and tubes, and the general
construction of steam boilers known as the Coinish or Lancashire description, in
which there are two fire-boxes of the usual cylindrical form At the end of
fire-boxes beyond the budge the flues are of flat form on one side like the
letter D with the flat sides facing each other, and parallel from end of fine-box
to the back end of boiler The D formed flues are connected together by transveise
tubes, and divided into three or more sections or series of tubes
The Invention will be clearly understood by reference to the annexed Diawings,
of which Figure 1 is a section through the fine-box of a Lancashue boiler, Figure 2,
section through the D flues, Figure 3, a longitudinal vertical section, and Figure 4,
a longitudinal houzontal section
A', A², are two cylindrical furnaces in the usual form which is continued to a
little distance beyond the five budge, D, D, are the flues leading from the termination
of the fire-box to the back end of the boilei in form like the letter D ; C, C, C³, are
water partitions or stops projecting transversely from the outside of the D formed
flues to about level with the outside series of coned water tubes, or to near the
centre of the partition or stop which projects from the other D flue, B, B, B, B, are
the coned water tubes generally known as "Galloway" tubes, F, F, are the man-
hole doors to facilitate the cleaning of the flues D, D, C is a water space to protect
the back end plate from injury by the heated gases in the flues, H, H, water space

page_text: in boiler, I is the bottom return flue, and J, J, are the side retuin flues to lead
the escaping gases to the chimney by the passages K, K, in which dampers L, L, are
arranged
In practice it will be found advantageous for perfect combustion and the con-
suming of the smoke to fire the furnaces alternately, No 1 furnace being fired first,
when this file has become bught No 2 furnace is then fired, when the smoko
issuing from No 2 furnace will be stopped in its duect course through the flue by
the first water stop C¹ The smoke and gases then take their course through the
first series of cone tubes B, B, when they enter flue No 1 where they intermix with
the highly heated gases from No 1 fui nace, then the smoke of No 2 furnace will be
much diminished, the heated gases of the two furnaces pass on to the water stop C4,
when then course is diverted though the second senes of cone tubes, then they pass
on to the C³ water stops, and then through between the thud sees of cone tubes
on to the next water stop G at the back end plate of boiler, they then take their
course through the fourth series of tubes, and then pass out at the end of boiler, when
the remaining heat and gases are conducted along buck flues under the bottom and
sidles of boiler in the usual mode, or as shown in the Drawing The arrows on the
Diawing show the direction the heat and gas s take through the boiler and flues
Figure is a tiansverse section of a vertical boiler in which the flues are of D
shape, Figure 6 is also a transverse section through the line X, X, of Figure 7, which is
a vertical transverse section at night angles to the vertical sectional view, Figure 8
In this aangenent the D flues from each fie are fitted with water partitions Ct, C³,
which compel the gases and products of combustion to take a zig-zag route before
they reach the top outlet or chimney The spaces between the water partitions are
partly filled with parallel tubes a, a, or they may be of conical shape if desned, and
fitted horizontally for the heat and gases to pinge against, and thereby effect a
quick genciation of steain The two fies of the vertical boiler can be ticated as
described for the Lancashire boiler fist herein-before described
I propose to utilize the waste heat after leaving the boiler by an arrangement of
pipes in the flue to the chimney The heated an I conduct through a pipe to the
back of the fire bridges where it mixes with and will tend in a great measure to
consume the smoke, or the smoke and gases may be carried around the outside of
the boiler in buick flues, the usual mode that boilers are set, before entering the
chimney
The water partition or stops that are placed in the flues act and are an
important element in my improvements, because they divert the smoke and gases
through the tubes and admit of expansion and contraction in the fire-boxes and
flues
I claim as this part of my Invention the construction of steam boilers with two D
shaped flues, each having water partitions projecting into the smoke way of the
other, the intervening spaces between the partitions having cone or other shaped
water tubes, the whole arranged as shown in Sheets 1 and 2 of the annexed
Drawings, and acting as and for the purposes described
The second part my Invention, which can be adapted to the boilers herein-before
described and shown as to boilers generally is represented on Sheet 3 of the annexed
Drawings This part consists of a cup casing which can be secured by bolts, or be
screwed into a boiler according to the arangement desired This casing has a
flange upon which a disc of copper or other like material is secured, preferably
between the flange of a dome, the other portion of which is open The interior of
the dome at the edge has a tiangular or other shaped piece of metal, such as brass
or steel, to rest upon the copper disc, in order that when the steam in the boiler gets
beyond what may be considered a safety pressure, the copper disc may expand and
become dished under the extra pressure whereby it is brought into diect contact
with the piece of brass or steel and fractures itself The steam then issues through
the fissure and out at the opening in the dome, indicating that the safety pressure
has been exceeded The steam by this simple contrivance is permitted to escape
until the proper working pressuie is re-obtained, when the dome aperture can be

page_text: •
temporarily closed by a cone-shaped plug, to which a weight may be suspended, or
a tap may be provided to the apparatus to shut off the steam when the fracture of
the copper disc takes place.
The combination of the copper disc and the piece of brass or steel as a cracker
may be modified in many ways, as may also be the arrangement of the taps
The number of discs may also be varied, so that one may be used as a signal disc
and another in the same apparatus as a safety disc after the signal disc has been
fractured and the steam outlet closed This will be fully understood by referring to
Sheet 3, in which Figure 1 represents a signal or safety disc apparatus supposed to
be fitted to the fi ont plate of a boiler A by its flange B, C is the bellied part of:
the apparatus with a flange D upon or into which the 11m or edge of a disc of
copper E is held by the flange F of the dome G, the bellied portion of which has a
turned up nozzle or outlet H for the escape of steam on the occasion of the disc
fracturing itself by an internal pressure of steam of the boiler with which the
chamber J behind the disc is in direct communication by the aperture K, L is a
triangular piece of brass, steel, or other hard metal, or it may be of rectangular
shape, as in dotted lines L¹ let into the shoulder of the dome, as in Figure 2, that
its bottom or inner face a may touch or nearly touch the disc when in a normal
condition, but which is pressed against by the disc on the disc being expanded and
dished by the extra piessure of steam until the disc is cracked or cut by it, the
steam then escaping and indicating that the pressure in the boiler has been exceeded
beyond the safety pressure
The escape of the steain by the nozzle can be temporarily closed by the conical
plug M, Figure 3, to which a magnet form of weight P is attached
Figure 4 represents an outside view, and Figure 5 a sectional view of an
apparatus to be screwed into o bolted to the top of a boiler as a safety signal of
pressure In this arrangement the outlet of the dome is furnished with a chisel-
like cutter or cracker depending from it by a screwed 11ng b, against the sharp
cutting edge or face of which chisel-like tool the disc on expanding comes into
contact, and is so to speak first punctured by the point c, and then cut open by the
angle edges d, d, to permit the steam to escape The stern of this apparatus is
provided with a tap N which is kept open while the disc is perfect, but when the
fracture occurs the tap can be turned to enclose the steam By this means a
working pressure of steam can be maintained, and a new disc can be at once fitted
in place, a plan preventing the stoppage of the engine and the work, and facilitates
the boiler being again in a safety state against any undue pressure that may after-
waids arise
Figure 6 represents an apparatus with a signal disc and a triangular shaped
cracker piece of hard metal, also a second disc of greater thickness than the signal
disc as a safety disc and a distinct triangular piece of metal as a cracker of same
The purpose of two discs of different thicknesses in one apparatus, and preferably
fitted on the front plate of a boiler, as is shown at L' in Figures 3 and 4, Sheet 1, 18
supposing the working pressure of steam to be 30 lbs per square inch, the signal
disc E is of a gauge to burst or fracture at 35 lbs, now suppose this disc breaks,
then the cone plug M is dropped into the outlet, and is weighted to retain the
steam within the boiler at the reduced pressure which it has been brought to by
the previous escape, the engine is thereby kept going, and should by any chance the
pressure again rise before a fiesh signal disc is fitted in, then either the cone plug
would be lifted, or in the event of this not doing so the safety disc P which is in
direct contact with the steam in the boiler would be acted upon and caused to expand
and put itself into cracking or fracture contact with the triangular or other piece of
hard metal in the dome The disc and cracker are applicable to engine cylinders
and other apparatus in which a pressure should not exist beyond a certain limit.
I am aware that copper discs have been proposed as signals of excessive piessure
of steam in boilers, but these have not answered in practice on account of the
yielding property of copper, it continued to stretch, and give without cracking o
fracturing, consequenty I make no claim to copper or to other metal or material

page_text: when used alone, but I do claim it under the second part of my heroin-before part
recited Letters Patent, when used in combination with an appliance with which it
shall be or shall come into contact for cracking, fracturing, or cutting the disc for
the purpose described
In witness whereof, I, the said William Rowan, have hereunto set my hand and
seal, this Nineteenth day of July, One thousand eight hundred and soventy-
soven.
WILL. ROWAN. (L.S.)