Improvements in and connected with Steam Generators and Furnaces therefor.
Year: 1897

page_text: Date of Application, 31st Mar., 1897
Complete Specification Left, 31st Dec., 1897-Accepted 19th Feb.,
1898
PROVIDIUNAL OF MUIFICATION.
Improvements in and connected with Steam Generators and
Furnaces therefor.
I, THOMAS LISIIMAN, of 13, Upper Berkeley Place, Clifton, in the County of
Gloucester, Engineer, do hereby declare the nature of this invention to be as
follows:-
In carrying out my invention I construct, and affix my various improvements in
the manner hereinafter described, the said improvements comprise diverse
mechanical appliances for better production of steam, and steam power, by per-
fecting combustion and circulation of the water, heating and also greatly purify-
ing the feed water, heating air and steam, and also obtaining a more rapid con-
version of water into steam. The said improvements in combination form a more
powerful simple, cheaper, and efficient system of generating steam than has
hitherto been obtained. Some of my improvements are applicable and can be
adapted to steam boilers in general use, also to ordinary steam boilers, and other
furnaces for generating heat and perfecting combustion.
of
By the application of my improvements in these combined and complete forms,
I am able to supply air automatically heated at a high temperature to the fuel and
gases. The feed water is in a similar way highly heated and purified prior to and
on its reaching the heating tubes, through which it is caused to repeatedly circu-
late, during its conversion into steam, before arriving at the steam receiver. The
furnaces are furnished with apparatus for emitting heated air to the fuel and
gases, and also heated water to the whole system, a rapid circulation is secured,
highly heated air may be and by preference is, injected into a steam receiver
whereby the temperature and value of steam may be considerably increased. The
furnaces muy he supplied with fuel by hand in the ordinary way, but
a mechanical
by preference by means
device specially arranged
for this purpose.
The heating tubes and the water and steam receivers
may be connected and communicate by means of connection pipes, and valves con-
structed to allow of a tube or any part being repaired or taken out and replaced
by others without causing any stoppage or injury whatever, either to the efficiency
of the apparatus or to the mechanism driven a very important matter to war
vessels." All parts can be duplicated and all parts are accessible for examination,
cleaning or repairing. For the better attainments of the objects and application
of the process indicated by the preceding paragraphs I build a structure of rect-
angular or other suitable form externally consisting of material ordinarily adapted
to and suitable for the different purposes to which it is applicable. Internally the
various parts comprise a number of circular tubes, and vessels of ordinary manu-
facture. There are also circular vessels placed outside the structure communicat-
ing with the said internal tubes and vessels. The tubes placed internally are the
water heating tubes, and may be operated either aingly or in groups of two, or

page_text: more of such tubes, by preference in groups joined by means of a junction pipe
or elbow furnished by preference with a valve or valves. Automatic in action,
for shutting off communication between one tube and another, or a group of tubes.
When required one end of some of the said tubes are in communication with a
water receiver by means also of pipes and valves, whereby the water supply to the
said tubes may also be shut off, and in the design of these connections and con-
struction thereof is part of my improvements.
Above the water heating tubes referred to in the last paragraph I place in a
vertical or horizontal position a series of air heating tubes, communicating with
a receiver, the said receiver may have also delivered in to it a portion of the escap-
ing gases, from the furnace or furnaces, the heated air and gases are from thence
conveyed by a tube or tubes to and by a steam injector, or other suitable means
forced into the fuel and gases, in the furnaces and combustion chamber, at a higher
temperature than has hitherto by ordinary methods been obtainable. This is a
further improvement in the process of heating air for assisting combustion and
effecting thereby greater economy.
In connection with the air heating tubes referred to in the preceding paragraph
1 may in addition thereto place other tubes for heating air, which may be delivered
into the same receiver, or into a separate vessel, and from thence forced into the
steam receiver from a tube passing through the heated gases, by means of an
injector specially devised and furnished with double action automatic valves and
placed between the air outlet, and the steam inlet, and the other between the outlet
of the injector, and the inlet to steam receiver whereby a back or return current
to the air vessel is prevented.
By this process at no additional cost in fuel air is heated to a very high tempera-
ture and may be added to the steam increasing its power and value. The apparatus
may be so arranged that when not required for heating steam it may for that pur-
pose be dispensed with, and either joined with the wator heating tubes and used
in conjunction therewith. As to the air heating apparatus for assisting com-
bustion, this process of heating and increasing the temperature of steam, and the
means whereby I effect it are additional improvements.
Below the water heating tubes before referred to I place a furnace or furnaces
by preference furnished with grate bars placed at an angle or inclined from one
or each side of the walls thereof, extending to the floor part of the furnaces, on
the floor of which I place one or more apparatus comprising a number of tubes by
preference five, forming one set arranged in the form of a square the four outside
tubes are water tubes, and the centre one an air tube perforated along each side
with a number of holes, the other end of the tube is in communication with the
hot air supply, and the other end is blocked, the heated air under pressure is
forced into the tube which passes through the holes therein, to the fuel and gases
above the floor, and grate of the furnace. Air may also be admitted underneath
the grate bars through regulators provided for that purpose, or in the ordinary
way. The two lower water tubes at one end communicate with a water receiver
suitably placed by preference on the floor outside the structure, at the other end
they are joined to the two upper tubes which are at the outer end connected to a
second receiver situated above the first receiver the water thus entering at the outer
end of the lower passes along and returns by the upper tubes to the second receiver,
from thence to the water heating tubes, through which it is caused to circulate
and delivered into a third receiver, from whence it is transmitted to a steam
receiver placed inside the structure and operated on by the heated gases. The
water and steam receiver, the water heating tubes, and the tubes forming the
furnace apparatus, are in communication by means of pipes, junctions and valves
suitably arranged for their respective purposes. This apparatus has important
functions to perform.
First, it distributes heated air to the fuel and gases secondly heats the feed
water, thirdly supplies the whole system with water, and accelerates circulation,
and fourthly perfects combustion thereby effecting economy in the consumption of

page_text: fuel. The fuel may be supplied to the furnaces in the ordinary way, but by
preference by means of a mechanical device comprising a hopper or fuel holder
secured to the structure in a suitable position through which a spindle or a series
of spindles are placed resting on bearings provided for them. The spindles are
furnished with a series of discs or square plates placed at right angles to each
other, which operate against corresponding fixed projections, thereby forming
cutters for cutting the coal fuel into regular sizes, and also regulates the fuel
supply to the furnaces. The said spindle and dices are caused to revolve, the
motion being obtained by any known ordinary appliance.
These arrangements of a furnace or furnaces enable me to obtain better results
than are obtained by ordinary methods, and when used in combination with the
whole of my improvements herein referred to, enable me to produce apparatuses
more complete and ellicient in generating steam for steam power at any attainablo
pressure.
The number of tubes, receivers, and dimensions thereof, may be for the purpose
of this invention regulated by the power required.
1.
1
L
1 100%
FREDERIC PRINCE,
Agent for Applicant.
Improvements in and connected with Steam Generators and
Furnaces therefor.
I, THOMAS LISHMAN, of 13, Upper Berkeley Place, Clifton, in the County of
Gloucester, 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:-
This invention relates to improvements in and connected with steam generatora
and in furnaces therefor, and has for its object to provide a steam generator which
is more simple and efficient and which generates steam more quickly than steam
generators as heretofore made and in the construction of which the expensive
operations of riveting and caulking are dispensed with.
According to the invention I construct my generator of a lower water receiver
or drum and an upper steam and water receiver or drum, the said receivers being
connected by rows of horizontal pipes or tubes which are so connected with one
another that the water circulates through the generator in a zig-zag fashion as
hereinafter described. The connections between the rows of tubes are provided
with valves preferably automatic in action whereby should a pipe burst the valve
automatically shuts off the water therefrom so that it can be removed and replaced
without interfering with the operation of the generator. All the tubes employed
are formed with flanges welded thereon and all the connections are made outside
the casing of the generator, that is to say, protected from the effect of the heat of
the furnace, by bolts passing through the flanges so that no riveting or caulking
is required.
The feed water is initially conveyed to a pipe placed in the ashpit of the boiler
50 that it is preliminarily heated after which it flows through tubes surrounded
by the fuel in the furnace as hereinafter described.
The air required for combustion passes through a chamber through which the
gases of combustion flow on their way to the chimney whereby it is heated and it
then flows into a perforated chamber surrounded by the water tubes in the grate

page_text: and through the perforations of which it escapes into the fuel. In conjunction
with this perforated air supply tube when a double furnace is employed, I pro-
vide an arrangement of sliding jacket wheroby the air supplied to one side thereof
can be cut off so that only one furnace is fired.
To enable my invention to be fully understood I will describe it by reference
to the accompanying drawings in which:
Figure is a front view of a steam generator constructed according to the
invention:
Figure 2 is a section on the line 2-2 Figure 1:
Figure 3 is a sectional view illustrating the automatic valve which I advantage-
ously employ in connection with the water tubes:
Figure 4 is a sectional elevation illustrating the sliding jacket for controlling
the air supplied to the furnace; and,
Figure 6 is a cross section thereof.
Figures 3, 4 and 5 are drawn to a larger scalo than Figures 1 and 2.
a is the casing of the generator the said casing being of suitable construction,
b is the furunce contained at the lower part of the said casing, the said furnace
being in the drawing shewn double and arranged to be fired from each side of the
generator. c is the ash-pit of the furnace, and d is the pipe which passes through
the said ash-pit and into which feed water is forced through the inlet d'arranged
at one end thereof. The other end of the pipe d is connected by means of a neck e
with the lower water drum or receiver f. From this water receivor of the water
flows through the two pipes g which pass back through the casing of the generator
in the furnace where they are connected by means of an elbow or similar joint gl
with tubes g which pass back through the fuel above the tubes g and thence
through the frout of the generator casing and into a receiver h. The receiver h
is connected by means of suitable valves i, (in the drawing ordinary stop valves
are shewn) with a series of horizontal water tubes which pass completely through
the generator casing and each of which is in communication by means of an auto-
matic valve k, of the kind hereinafter described, with the end of a horizontal water
tube which passes back to the front of the generator and communicates by means
of an automatic valve k with the front end of a further water tube m; this tube m
passes completely through the generator casing a and communicates at its rear end
by a short neck (which may or may not be provided with a valve as desired) with
the rear end of a steam and water drum or receiver n which also passes completely
through the generator casing a and communicates at its front end by means of a
pipe with the lower water drum f. p is a steam pipe from which steam is
collected from the upper drum n.
j
As above described all the pipes are made with flanges welded thereon and all
the connections between the pipes and drums or receivers are effected outside the
generator casing (that is to say, in a position where they are protected from the
Leat of the furnace) so that all riveting and caulking is avoided and a steam
generator made according to the invention can be fitted together without recourse
to the usual operations employed in boiler making and which are more costly than
the operations of the fitting and turning shops.
To provide for the escape of any steam which may be generated in the tubes ³
which are exposed to the full heat of the incandescent fuel, I connect the said two
tubes with a pipe h' provided with cocks and which passes up into the steam and
か
water drum n above the water level. By this means the liability of the pipes ³
bursting by the generation of steam, is avoided.
The lower water drum also communicates by means of a pipe f with a water
tube which passes through the steam generator similarly to the other water
tubes and communicates at its rear end with a water tube arranged above it and
which passes back through the steam generator and communicates at its front end
through a downwardly extending pipe with the water receiver h. This, there-
fore, gives an additional circulating path for the water.
The valves which I advantageously employ for automatically shutting off the

page_text: flow of water to a water-tube should the latter burst comprises a casing ¹ Figure 3
having valve-seats 'q and q' 'to receive a ball valve r which can be held upon the
sent
where necessary, by a screw rod r¹ having a handwheel. In the said figure
the valve r is shewn screwed down upon the seat q. When the generator is in
operation, the hand-wheel is turned so as to allow the ball valve to be raised
from its seat by the circulation of the water, the said ball then being pushed into
a branch as shewn in dotted lines in the said Figure 3. Should the tube / now
burst, the ball is automatically forced from the position indicated in dotted lines on
to the seat so as to cut off communication between the tubes m and 7. The
valve at the other end of the tube which connects it with the tube is also cut
off in a similar manner, the ball in this case being forced against the seat g' so that
no water can now euter the tube which can, therefore, be removed and replaced.
This is of considerable importance in many cases particularly in the case of the
boilers of war ships.
The necessary air for supporting the combustion of the fuel is supplied, as above
indicated, by means of a tubes which passes into the said fuel between the
tubes 9, 9, 9. The said tube is provided on each side with a series of perfora-
tions so that air can pass directly into the mass of the fuel of both furnaces.
The perforated pipes communicates by means of a pipe with a number of tubes u
which pass through the smoke-box of the boiler so that air is drawn in through
the said pipes, as indicated by the arrows, and is heated in its passage therethrough
and thence through the pipe t into the perforated tubes from which it escapes
into the furnace., Figures 2, 4 and 5, is the sliding jacket which I advantage-
ously provide for cutting off the supply of air to one furnace when desired. The
said jacket is suspended at its two ends upon the perforated tubes by means of
rings, which pass around the said tubes, and is arranged to be turned upon
the said tube s by means of a lever so as to leave both series of perforations s
open as indicated in the Figures 4 and 5 or so as to close one or the other set.
In the case of small boilers such as donkey boilers, I preferably use only a single
furnace which can be supplied with air in the ordinary manner and not by means
of the perforated tube.
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. A steam generator comprising a lower water drum which is fed by a pipe pass-
ing through the ash-pit and communicates by a number of zig-zag pipes with an
upper steam and water receiver or drum in communication by one or more down-
take tubes with the said water receiver, the water tubes having welded flanges and
being connected together and to the drums outside the generator casing, sub-
stantially as, and for the purposes, hereinbefore described.
2. In a steam generator of the kind described in the preceding claiming clause
causing the water to circulate through tubes passing through the incandescent fuel
and in communication with the steam receiver, substantially as and for the purpose
herein before described and as illustrated in the accompanying drawings.
3. In a steam generator supplying air to the furnace through a perforated tube
passing through the fuel and supplied with air which has been preliminarily heated
by passing through the smoke-box substantially as described and as illustrated.
4. In an arrangement for supplying air to the furnaces of steam generators of
the kind described in the preceding claiming clauso and wherein the air supply
pipe is perforated on both sides, providing a sliding jacket operated by suitable
means whereby either both sets or either one set of perforations can be opened for
supplying air, substantially as described and illustrated in the accompanying
drawings.
5. In a steam generator of the kind described in Claim 1, the employment for
connecting the water tubes, of automatic valves of the kind described and illus-
trated in Figure 3 of the accompanying drawings.

page_text: 6. The combination and arrangement of parts forming the improved steam
generator, herein before described and illustrated in the accompanying drawings.
Dated this 24th day of December 1897.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.