Improvements in Steam Generators.
Year: 1893

page_text: Date of Application, 4th Aug., 1893
Complete Specification Left, 25th Apr., 1894-Accepted, 2nd June. 1894
Improvements in Steam Generators.
1 WILLIAM HENRY MIRFIN of No. 8 Duncan Street, Longsight, Manchester,
in the County of Lancaster, Engineer, do hereby declare the nature of this
invention to be as follows:-
Stationary steam generators as most usually constructed consist in each case of a
cylindrical shell provided with an internal Hue or with two flues. Owing to the
adopted high steam pressures and to the large sizes often required the weight of an
ordinary generator is very great and causes difficulty and expense in transport and
mounting. Generators are also made in sections connected together but such
generators are open to objections principally owing to the absence of a self-
contained furnace and to the difficulties in inspecting and repairing. The object of
my invention is to combine the advantages of the two classes of generators. In
my invention combine together a number of sections but the front section is in
the form of a short Cornish or Lancashire boiler and all the sections are so
constructed as that they can be entered for inspection and repairs. The front
section would be only about long enough to contain the furnace or furnaces and
may be termed the furnace section. Such furnace section would have an internal
fire flue or more than one such flue and would have water and steam spaces
connected with the spaces in the other sections but by preference the steam space
would be comparatively small especially in the cases of apparatus for generating
high pressure steam. The furnace section and each of the other sections which I
will term water sections for distinction would in some cases be connected with a
steam reservoir or with steam reservoirs and the steam spaces would in some or in
all cases have direct connecting passages the water spaces being also connected.
The water sections might be of any suitable formation so long as each could be
entered but I prefer to use an improved form specially adapted to my purpose.
Such improved water section would consist of an upper and a lower cylindrical
chamber connected together by means of water tubes which by preference would
be of conical formation. The lower chamber, the water tubes and part of the
upper chamber would be filled with water. The upper chamber would be provided
with a man-hole and be connected with the steam pipe or reservoir. The lower
chamber would be formed with ends and with means for connecting the water
spaces of contiguous water chambers and would be formed with a man hole or the
water connections might be made large enough to permit passage from one section
to another in which case a man-hole might be on the front or rear section only or
on both. The connection between the lower chambers may be effected by means
of faced blocks or of short tubes screwed into the two end plates or secured thereon
by expansion or similarly fixed in rings riveted or bolted to the inner faces of such
plates or by means of expansion joints or other suitable connections. I might
make the lower chambers in the form of hollow cylinders and connect them
together end to end so as to form a continuous tube adapted to be entered through
a man-hole at the front or back end of the generator. The connection may be
effected by means of rivets and ordinary joint rings or of expansion joint rings or
the ends of the short tubes may be provided with flanges or with faced rings to
facilitate the connecting of the sections by means of bolts or rivets. In the cases
wherein the man hole would be at the rear I may provide for access to be had to
the lower chambers through a tube passing through the back flue. I prefer to
make the cylindrical shell of each of the chambers in a section without a horizontal
seam such shell being either welded or rolled into form without welding. The ends

page_text: of an upper chamber would consist of dished or flanged discs. If considered to be
advisable the upper chambers might be connected together by steam passages
independently of the connection by means of the steam reservoir. The water
sections would be arranged in a row or in two rows or it might be in more than two
rows. In the cases of generators having two rows of water sections the furnace
section may have two furnaces or a large furnace flue divided by water tubes or two
furnace sections may be used. The two rows of water sections might or might not
be separated by a mid wall. The sections would by preference be so seated as
that the gases and products of combustion would pass below the upper chambers
and above the bottom chambers or tube to the back flue and would return along
one side of the bottom tube to the front and from the front along the other side of
the tube to the back or to flow from the back toward the front along both sides of
the bottom chamber returning below such chamber. The arrangement of the flues
or passages may however be varied. All the sections might be connected with a
discharge pipe for sediment and I prefer to shield this from the direct action of the
heated gases by means of longitudinal plates or tiles which would also serve to
separate the flues. All the ordinary or suitable mountings such as safety valves
gauges and low-water alarms could be applied to the furnace section which would
be better adapted to receive such mountings than the ordinary form of section used
in a sectional generator. I may use dce shaped sections having tube plates
connected together by means of tubes expanded in, or of Galloway or parallel
flanged tubes.
Dated this 3rd day of August 1893.
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.
COMPLETE SPECIFICATION.
Improvements in Steam Generators.
I WILLIAM HENRY MIRFIN of No. 8 Duncan Street, Longsight, Manchester, in
the County of Lancaster, Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement and accompanying drawings :—
Steam generators as most usually constructed, consist in each case of a cylindrical
shell provided with an internal flue or with two or more flues. Owing to the now
generally adopted high steam pressures and to the large sizes often required, the
weight of an ordinary generator is very great, and causes difficulty and expense in
transport and mounting. Generators have also been made in sections connected
together, but such generators are open to objections principally owing to the
absence of a self contained furnace and to the difficulties in inspecting, cleansing
and repairing. The object of my invention is to combine the advantages of the
two classes of generators.
In my invention I combine together a number of sections but the front section is
in the form of a short Cornish or Lancashire boiler and all the sections are so
constructed as that they can be entered for inspection cleansing and repairs.
The front section would be only about long enough to contain the furnace or
furnaces and may be termed the furnace section. Such furnace section would have
an internal fire flue or more than one such flue and would have water and steam
spaces connected with the spaces in the other sections.
The furnace section and each of the other sections, which I will term water
sections and steam sections for distinction, would be connected with a steam pipe
or reservoir or with steam reservoirs, and the steam spaces might in some or in all
cases have direct connecting passages, the water spaces being also connected.
The ordinary or suitable mountings such as manholes, safety-valve, water and
steam gauges feed water valve, sludge cock &c. would be applied to the furnace

page_text: form of section used in a sectional generator.
To render my invention clearly understood I will now proceed to describe the
same more particularly and with reference to the annexed three sheets of illustrativė
drawings.
Sheet 1 contains views of what I consider to be a useful type of boiler, constructed
according to my invention.
Fig. 1 is partly a longitudinal section and partly a side elevation of my improved
boiler.
Fig. 2 is partly a front elevation and partly a cross section of the furnace
section A.
Fig. 3 is a cross section of the sectional portion of the boiler consisting of the
Jower and purely water chambers B and the upper or partly water and partly
steam chainbers C.
The furnace section A is practically a short or dwarf Lancashire or double
flued boiler. The flues a a contain the furnaces and bridges c c. This dwarf
boiler A is easily accessible through the manholes d d for cleansing and other
purposes. Upon this dwarf boiler I mount all of the accessories required which are
so easily mounted upon a boiler of this type, but so difficult to combine properly with
the usual sectional boiler. For example the boiler A carries the manholes dd, and
also the safety valve, water and steam gauges, feed water valve, sludge cock &c.
and in short all of the essential fittings and mountings of an ordinary boiler, applied
and acting in the usual manner and as shown in the drawings. As the water level
in the boiler A is about similar to that in an ordinary boiler, no difficulties or
special arrangements have to be met or made in arranging and applying these
fittings, and this I look upon as a special advantage inherent to my invention.
g
The water chambers B, and steam chambers Care arranged in line with and
behind the boiler A, the steam chambers C standing above the water chambers B.
The bottoms of the water chambers B are about level with the bottom of the
boiler A but the tops of the steam chambers C are preferably above the level of
the top of the boiler A so as to give more steam space, although this is not essential.
The first water chamber is counected to the lower part of the boiler A. by one or
more tubes or necks e which may be secured by expanding, bolting, screwing
rivetting or in any other desired mode. The several water chambers B com-
municate with each other in the same manner, as clearly shown in the drawings.
This allows free access of water from the boiler A to the chambers B or vice versa
whereby a constant supply of water to all, is preserved. The water chambers B
also communicate with the steam chambers C by means of the tapered connecting
tubes f, and also by means of the short branches 9 which are large enough to allow
a man to pass.
Manholes are also formed in the steam chambers C, so that
access can be had both to the steam chambers C (via the manholes ) and also to
the water chambers B, via the passages y. Thus access for cleansing and repairs
can be had alike to the boiler A, water chamber b, and steam chambers C.
different steam chambers C are connected to the steam space of the boiler A by
means of a steam pipe fitted with an additional safety valve j and stop valve k.
The steam spaces of the steam chambers are also placed in communication with
each other by means of the same steam pipe i, a branch proceeding from the pipe
to each steam chamber. In addition to this I might however bring the steam
spaces of the steam chambers into still more direct communication with each other
by placing a tube / between the ends as shown in Fig. 4. The shells of the water
and steam chambers might be rolled as weldless rings, but at present I make them
from plates rivetted or welded together.
The
The space between the ends of each adjoining steam chamber and each
adjoining water chamber, is bridged over by arched plates m, m, in the one
case to prevent the egress of smoke from the flues to the atmosphere and
in the other case to close communication between the flues x and y y all as
clearly shown in the drawings.
:

page_text: Sludge pipes and cocks may be connected to the foot of each water
chamber B. The described composite boiler when stationary is supported in a
suitable flued brick setting.
The heated products of combustion from the furnaces b b in the boiler A,
flow over the bridges c c and along the flues in the setting to the back of
the sectional boiler (see Figs. 1 and 3). Here the products of combustion are
diverted and split and return to the front of the boiler through the side flues y y
(see Figs. 1, 2 and 3). Towards the front of the boiler A the two side currents
of hot gases re-unite, and pass again to the back of the generator through the
bottom flue and so past the damper to the chimney. The dwarf boiler A
is carried on supports n see Fig. 2 and the sectional boiler behind is carried
on standards o (see Figs. 1 and 3). Having thus described and illustrated the
actual 'construction of a boiler made in accordance with my invention, its
advantages will be apparent to every practical boiler maker or steam user.
In
almost every built-up sectional boiler in the market, the peculiarities of arrange-
ment, the number of small pipes, tubes and spaces, which cannot possibly be got at
to be inspected cleaned or repaired, the numerous and constantly leaking joints, the
difficulties of fixing and the costliness of construction and maintenance, present
such formidable objections to their use, that sectional boilers, have never made much
headway among steam users. The present invention is the result of very long
experience of both the advantages and disadvantages of sectional boilers, and in
my present boiler it has been my aim to retain the advantages of the sectional
boiler while avoiding its disadvantages.
For example by the use of the dwarf Lancashire boiler A in front, I am enabled
to use the most economical form of internal flues and furnaces, and the whole of
the necessary fittings of the boiler can be applied to this dwarf portion and are
easily mounted and accessible. Then the steam and water chambers which form
the sectional part of the boiler are all of reasonable size and weight for transport
and are all accessible when in situ so as to be easily inspected cleaned and repaired.
If one of the chambers B or C should give way it is only necessary to renew that
chamber, and this can be done without any great difficulty, as all of the steam
chambers and all of the water chambers are respectively alike; and for this
reason also they can be manufactured in quantities and be made interchangeable
this being a very economical system of manufacture.
It will be evident that my improved system of construction is subject to many
modifications in detail and arrangements.
One or two of the more obvious modifications are shown on Sheets 2 and 3 but
it must be understood that I do not rigidly confine myself only to what I have
shown and described.
In Sheet 2 Fig. 5 is partly a longitudinal section and partly a side elevation of
my improved composite boiler in which there are two ranges of water and steam
chambers instead of one as shown in Sheet 1. Fig. 6 is partly a cross section of
the boiler A and partly a cross section of the steam and water chambers behind.
As in the former illustrations, the front of the boiler constitutes a dwarf
Lancashire boiler A and behind there is a double row of water chambers B B and
steam chambers CC. The steam pipe i from the boiler A communicates by means
of tranches with the various steam chambers C and these steam chambers C
have manholes to allow access to the chambers. The water chambers B are
rather less in size than those illustrated in Sheet 1 and are connected to the steam
chambers C by conical tubes f and the smaller expanded in parallel pipes f
To provide for access to the water chambers B I apply a manhole p to one of the
chambers B, say to the last chamber of the row, as indicated in dotted lines
in Fig. 5. Then to enable access to be had from chamber to chamber, the ends of
the chambers are left open and counected by an annular ring q, so that when
access is had to one of the chambers a man may pass from chamber to chamber
throughout the entire row. Sludge pipes r for removing dirt from the chambers B
are shown in dotted lines in Figs. 5 and 6. The smaller connecting pipes it'

page_text: expose more heating surface to the products of combustion than the larger
conical tubes shown in Sheet 1, but if desired the said larger conical tubes
might be used in the double rank sectional arrangement shown in Sheet 2 and this.
use of the larger conical connecting tubes is indicated on the left hand side of the
sectional view in Fig. 6.
The boiler A is connected at the foot to the first water chamber by a faced ring:
or plate connection 3.
In addition to or in lien of connecting the dwarf boiler A to the steam,
chambers C by the steam pipe i as described, the said boiler might be connected:
to the first chamber C by a short neck or thimbles as shown in Fig. 7, and the
several steam chambers might communicate with each other in the same manner.
Also, instead of providing for admission by means of a manhole from the
boxed-in passage or tunnelt beneath the chambers B as described and as most
clearly shown in Fig. 6, I might prolong an extension u from the last chamber B
as shown in Fig. 8 and carry the extension u through the back of the brick
setting. A man-hole on the projecting end of the extension would admit of the
desired ingress and egress.
As in the former instance the composite boiler is supported in a suitable brick
setting, with flues arranged to circulate the heated products of combustion from
the furnace to the best advantage. As already stated a portion of the lower-
return flue y is boxed off by plates e so as to form a tunnel along which a man may
go to the sludge fittings and manhole p.
In Sheet 3 Fig. 9 is a cross section of the dwarf boiler A and Fig. 10 a
longitudinal section of the same shown connected to the water and steam
chambers B and C.
Instead of a double flue as in Sheets 1 and 2 the boiler A has a single hour-
glass shaped flue w within which conical or other tubes 2 are arranged. There is.
thus a larger grate and flue surface. The boiler A and the first water chamber B
communicate by means of faced rings or branches 4 bolted together as shown
in Fig. 10 or by a screwed tube 5 with nuts as illustrated in Fig. 11. The steam
space of the boiler A communicates with the first steam chamber C by a pipe 6 as.
shown. This may be in addition to or in lieu of the steam pipe shown in the
foregoing sheets.
As a means of preventing priming, I might mount an auxiliary steam chamber
or dome above the steam chambers Cand boiler A as indicated in Fig. 12. This.
steam chamber which is marked 7 communicates with the boiler A and with the
chambers C by the branches 8 and 9 and the steam may be led away from the said
chamber 7 by a junction valve or pipe 10. Thus all danger of priming is avoided
and such an additional steam chamber might be found useful in cases where boilers
made upon my improved principle were adapted to marine purposes.
I have throughout described the water and steam chambers B and C as of
cylindrical formation but I do not confine myself to this as they might be of any
suitable shape. For example I might make these chambers of a D form in cross
section as shown in Fig. 13, or they might be of spherical, oval, corrugated or
other shapes. The number of the aforesaid water and steam chambers or sections
is immaterial. As the improved composite boiler is composed of so many light.
and easily handled parts, the advantages for purposes of transport will be easily-
appreciated.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what.
I claim is.
1. The general arrangement, construction and combination of composite steam
generators of the indicated nature and substantially as described and shown.
2. The combination of an internally flued and fired boiler (preferably shortened
or dwarfed) with a sectional generator of the indicated nature, substantially as
hereinbefore described and as illustrated.

page_text: 3. The improved composite steam generator consisting of a shortened or
dwarfed Lancashire or other internally flued and fired boiler, carrying the
requisite boiler fittings and used in combination with a series of separate and
preferably similar cylindrical or other suitably shaped chambers or compartments
containing water and water and steam and communicating with the said drawf
boiler and with each other, the said boiler and chambers being easily accessible
for the purposes of inspecting, cleaning and repairing, substantially as hereinbefore
described and illustrated.
4. In a composite boiler of the indicated nature the employment of series of
cylindrical or other suitably shaped chambers such as B and C, the chambers B
arranged in line with each other and being filled with water and the chambers C
also arranged in line with each other, but above the chambers B, and only partly
filled with water, the said chambers communicating with an internally fired dwarf
boiler in front, and also communicating with each other, and arranged so as to be
accessible for the purposes of internal inspection cleansing and repair, substantially
as described and illustrated.
5. The construction arrangement and combination of composite steam generator
substantially as described and as illustrated on Sheet 1 of the drawings.
6. The arrangement, construction and combination of composite steam generator
with double rows of water and steam chambers B and C substantially as described
and as illustrated on Sheet 2 of the drawings.
7. As alternative means for obtaining access to the chambers B, the extension u
projecting from the last chamber through the brick setting and closed with a
man-hole or other door or cover substantially as described and shown in Fig. 8
Sheet 2 of the drawings.
8. In a boiler of the indicated nature and construction the application of an
additional or auxiliary steam chamber or steam chambers or reservoirs above the
level of the boiler A and steam chambers C for the purpose of preventing priming
substantially as described and as illustrated in Fig. 12 Sheet 3.
9. In a composite steam generator of the indicated type, the modified forms of
construction arrangement and configuration described with reference to Sheet 3 of
the drawings.
Dated this 27th day of April 1894
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.