Improvements in or connected with Steam Generators.
Year: 1894

page_text: Date of Application, 22nd Mar., 1894
Complete Specification Left, 22nd Dec., 1894-Accepted, 2nd Feb., 1895
Improvements in or connected with Steam Generators.
We, JAMES JONES MELDRUM, THOMAS FREDERICK MELDRUM, and JOHN
WESLEY MELDRUM, all of Atlantic Works, City Road, Manchester, in the
County of Lancaster, Engineers, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to internally fired steam generators, and mainly to
the mode of firing, and the arrangement of, and constructions connected with the
furnaces, and to the means of supplying air thereto, for the combustion of fuel ;
and it also has reference to the utilization of towns' refuse, or analogous materials,
or poor fuel, for the generation of steam for useful purposes.
Our invention has mainly for its object to provide improved special constructions
or arrangements of, or parts of, steam generators; and modes of or arrangements
for the better and more easy working of the fires or furnaces of steam generators.
According to a part of this invention, the furnace of a steam generator comprises
fire-bars or bearers, a dead plate, and a hopper or conduit disposed above the dead
plate, which hopper in some cases passes through the generator, by or through
which the material to be burnt is charged onto the dead plate. This grate,
comprising the bars and dead plate, is preferably disposed upon an inclination so
that the material may be pressed or pulled from the end at which it is introduced,
that is from the dead plate, onto the grate bars. At the end opposite that at which
the fuel is introduced, a door, adapted to be slid or otherwise suitably moved, is
provided, through the aperture of which the furnace is worked, and the material
on the dead plate may be raked or worked down the grate onto the grate bars.
In action, the material, that is towns' refuse, or like material or fuel (or coal as
the case may be) is fed from a hopper through the conduit above the dead plate
onto said dead plate, and assuming the apparatus to be in operation, the material
thereon becomes heated or baked and moisture or volatile, matters are driven off by
the heat, and these pass over the material which is in a state of combustion, and the
combustible portions are burned. All the gases and vapours then pass on through
the furnace into a combustion chamber, and then return in the opposite direction
through or over other heating surface of the steam generator, such as tubes, to
which they give up their heat to a large extent.
The air used for combustion of material on the grate is, in some cases, heated
prior to its being delivered into the ashpit, and this is done in such cases by passing
such air over the surfaces heated by the products of combustion after they have
left the steam generator proper which may be called a regenerator,-the air being
caused to pass through same and delivered into the ashpit-which is a closed one-
by steam jet or other blowers, or exhausters, to the inlets of which the air is carried
through or by a suitable chamber or conduits.
In one arrangement and construction of parts of apparatus under this invention,
the steam generator portion proper comprises one or more internal furnace flues
within an outer shell, and return tubes extending between front and back plates,
forming the ends of the shell, with steam jet blowers forcing heated air into the
ashpit below the fire-bars, and the bodies of which lie wholly or mainly within the
ashpit, and horizontally or substantially horizontally; the type of blowers that
may be used with advantage being those known as "Meldrum blowers," but other
arrangements and suitable types of blowers may be used. The dead plate onto

page_text: which the material is introduced is placed in the furnace at the back, and the whole
grate inclines downwards towards the front, where a door through which the
material is operated upon, is placed; whilst a second dead plate is provided at the
front between the end of the grate-bars and the said front door, onto which
incombustible matters as clinker &c. are worked, and from which they are finally
removed from the apparatus.
:
In some cases the furnace is lined with fire-brick or other fire resisting material
which is preferably built only above the material being burnt and such lining
may rest upon angle irons or equivalent supports on each side of the flue, say some
distance from the grate.
The front portion may constitute, or will have, a chamber or chambers serving
as a combustion chamber or chambers, into which the gases of combustion and
vapours will pass from the furnace, and from which they will pass through boiler
tubes in the steam generator and travel back to the back end of the apparatus;
where they enter the air heating part of the apparatus, or regenerator.
In conjunction with the forced draught under the grate, there may be used a
steam jet (or other) exhausting device beyond the regenerator, by which the flow
of gases and vapours through the said boiler heating tubes is assisted, and by
which the pressure in the combustion chamber or at that part, will be prevented
from becoming greater than that of the atmosphere.
At the front, or both front and back, a door or doors will be provided in the
ashpit by means of which access can be had thereto, as and when desired.
In connection with the front portion of the furnace or furnaces, in one design,
there would be provided a fire-brick arch or arches, with which, in some cases,
water cooled parts, such as end boxes, or a base box as a "dead-plate," or tubes
may be provided, to limit the degree of heat at this part. These arches serve or
may serve both to assist in effecting complete combustion of the combustible
matters, as well as to protect the erosive action of the gases, and the burning of
the plates.
Also the tube plates may be protected by means of a fire-brick wall having
perforations corresponding with the ends of the fire tubes.
After
At the back end of the steam generator, the gases are led from smoke boxes
through the regenerator chamber or chambers, and through which also the cold air is
passed, the cold air travelling over surfaces heated by the waste gases.
leaving the regenerator, such gases, as above stated, are passed into the outlet, and
may be forced by a steam jet or jets through the outlet or outlets, which may be in
the form of a steam jet exhauster.
The cold air is carried to the blowers and ashpit through the regenerator, and
thence by a conduit, which may enclose that part of the ashpit closing plate in
which the blower or blowers is or are held; and in some cases also, a door, above
referred to, is provided. There may be also provided above the dead plate, another
door for gaining access to the back end of the fire-grate.
In some cases, as a modification of the above construction and mode of operation,
the material or fuel may be introduced into the furnace by being thrown in through
the front door, preferably to the back of the grate.
In some cases, in lieu of the fire-bars being fixed or stationary, we may employ
a grate arrangement with moving or movable fire-bars, or an endless travelling
grate may be used, and adapted to move the fuel towards the front door of the
furnace.
According to one special construction of steam generator having a cylindrical
furnace or furnaces and return tubes, this may have a combustion chamber or
chambers at one end with water surrounding it or them in the usual way, whilst in
the end water space it is provided with a doorway or doorways, and door or doors,
through which the fire on the grate is worked, as for the removal of clinker and
ash; a doorway or doorways and door or doors for gaining access to the ashpit is
or are also provided at this end. A modification of such a steam generator as that
last described may consist in having a flat water chamber at the combustion

page_text: chamber end, separated from the main part of the steam generator, but connected
up with same by tubes at the bottom and top. This water chamber will be
provided with an aperture for a door or doors as above described, and for the same
purpose, the space between it and the body of the steam generator constituting the
combustion chamber, from which the return tubes carry the gases of combustion.
A sight hole may be provided through this chamber-or through the water space
of the end of the combustion chamber of the boiler last described-for seeing into
the furnace, and the state of the fire upon the grate.
In a "Cornish" or "Lancashire steam generator arranged to be operated
according to this invention, the gases of combustion are first caused to travel
towards the front and then back through the side flue, and then through internal
flues; after which they may be led through other flues.
In cases where steam generators constructed as above described are used for
burning refuse material, or analogous, or like materials, or when desired, they may
be provided with furnaces and parts as above described, or any of them, and
arranged to be worked and operate accordingly.
It is to be stated that different parts, or combinations of parts, under this
invention are independent of each other, and may be used accordingly, in different
steam generators to which they may be applicable; and, on the other hand,
improvements or parts, or combinations of parts, of or under the invention may be
used, two or more of them, conjointly, in steam generators.
Dated this 21st day of March 1804
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicants' Patent Agents.
Improvements in or connected with Steam Generators.
We, JAMES JONES MELDRUM, THOMAS FREDERICK MELDRUM, and JOHN
WESLEY MELDRUM, all of Atlantic Works, City Road, Manchester, in the
County of Lancaster, Engineers, 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 has reference to internally fired steam generators, and mainly to
the mode of firing, and the arrangement of, and constructions connected with the
furnaces, and to the means of supplying air thereto, for the combustion of the fuel.;
and it also has reference to the utilization of towns' refuse, or analogous materials,
or poor fuel, for the generation of steam for useful purposes.
Our invention has mainly for its object to provide improved special constructions
or arrangements of, or parts of, steam generators; and modes of or arrangements
for the better and more easy working of the fires or furnaces of steam generators.
According to a part of this invention, the furnace of a steam generator comprises
fire-bars or bearers, a dead plate, and a hopper or conduit disposed above the dead
plate, which hopper in some cases passes through the generator, by or through
which the material to be burnt is charged onto the dead plate. This grate,
comprising the bars and dead plate, is preferably disposed upon an inclination so
that the material may be readily pressed or pulled from the end at which it is
introduced, that is from the dead plate, onto the grate bars. At the end opposite
that at which the fuel is introduced, a door, adapted to be slid or otherwise suitably
moved, is provided, through the aperture of which the furnace is worked, and the
material on the dead plate may be raked or worked down the grate into the grate
bars.
In action, the material, that is towns' refuse, or like material or fuel (or coal as
the case may be) is fed from a hopper through the conduit above the dead plate

page_text: onto said dead plate, and-assuming the apparatus to be in operation--the material
thereon becomes heated or baked and moisture or volatile matters are driven off by
the heat, and these pass over the material which is in a state of combustion, and the
combustible portions are burned. All the gases and vapours then pass on through
- the furnace into a combustion chamber, and then return in the opposite direction
through or over other heating surface of the steam generator, such as tubes, to
which they give up their heat to a large extent.
The air used for combustion of material on the grate is, in some cases, heated
prior to its being delivered into the ashpit, and this is done in such cases by passing
such air over surfaces heated by the products of combustion after they have left the
steam generator proper-which may be called a regenerator,-the air being caused
to pass through same and delivered into the ashpit-which is a closed one-by
steam jet or other blowers, or exhausters, to the inlets of which the air is carried
through or by a suitable chamber or conduits.
In one arrangement and combination of parts of apparatus under this invention,
the steam generator portion proper comprises one or more internal furnace flues
within an outer shell, and return tubes extending between front and back plates,
forming the ends of the shell, with steam jet blowers forcing heated air into
the ashpit below the fire-bars, and the bodies of which lie wholly or mainly.
within the ashpit, and horizontally or substantially horizontally; the type of
blowers that may be used with advantage being those known as "Meldrum
blowers" : but other arrangements and suitable types of blowers may be used.
The dead plate onto which the material is introduced is placed in the furnace
at the back, and the whole grate inclines downwards towards the front, where a
door, through which the material is operated upon, is placed; whilst a second
dead plate is provided at the front between the end of the grate-bars and the
said front door, onto which incombustible matters as clinker, &c. are worked, and
from which they are finally removed from the apparatus.
In some cases the furnace is lined with fire-brick or other fire resisting material,
which is preferably built only above the material being burnt; and such lining may
rest upon angle irons or equivalent supports on each side of the flue, say some
distance from the grate.
The front portion may constitute, or will have, a chamber or chambers serving
as a combustion chamber or chambers, into which the gases of combustion and
vapours will pass from the furnace, and from which they will pass through boiler
tubes in the steam generator and travel back to the back end of the apparatus ;
where they enter the air heating part of the apparatus or regenerator.
In conjunction with the forced draught under the grate, there may be used a
steam jet (or other) exhausting device beyond the regenerator, by which the flow
of gases and vapours through the said boiler heating tubes is assisted, and by which
the pressure in the combustion chamber or at that part, will be prevented from
becoming greater than that of the atmosphere.
At the front, or both front and back, a door or doors will be provided in the
ashpit by means of which access can be had thereto, as and when desired.
In connection with the front portion of the furnace or furnaces, in one design,
there would be provided a fire-brick arch or arches, with which, in some cases, water
cooled parts, such as end boxes, or a base box as a "dead-plate," or tubes may be
provided, to limit the degree of heat at this part.
These arches serve or may
serve both to assist in effecting complete combustion of the combustible matters,
as well as to protect the corrosive action of the gases, and the burning of
the plates.
The tube plates may also be protected by means of a fire-brick wall having
perforations corresponding with the ends of the fire tubes.
At the back end of the steam generator, the gases are led from smoke or waste gas
boxes through the regenerator chamber or chambers, and through which also the
cold air is passed, the cold air travelling over surfaces heated by the waste gases.
After leaving the regenerator, such gases, as above stated, are passed into the outlet,
บร

page_text: and may be forced by a steam jet or jets through the outlet or outlets, which may
be in the form of a steam jet exhauster.
The air is carried to the blowers and ashpit through the regenerator, and thence
by a conduit, which may enclose that part of the ashpit closing plate in which the
blower or blowers is or are held, and in which also, in some cases, a door, above
referred to, is provided. There may also be provided above the dead plate, another
door for gaining access to the back end of the fire-grate.
In some cases, as a modification of the above construction and mode of operation,
the material or fuel may be introduced into the furnace by being thrown in
through the front door, preferably to the back of the grate.
In some cases, in lieu of the fire bars being fixed or stationary, we may employ a
grate arrangement with moving or movable fire-bars, or an endless travelling grate
may be used, and adapted to move the fuel towards the front door of the furnace.
According to one special construction of steam generator having a cylindrical
furnace or furnaces and return tubes, it may have a combustion chamber or
chambers at one end with water surrounding it or them in the usual way, whilst in
the end water space it is provided with a doorway or doorways, and door or doors,
through which the fire on the grate is worked, and for the removal of clinker and
ash; a doorway or doorways and door or doors for gaining access to the ashpit is or
are also provided at this end. A modification of such a steam generator as that
last described may consist in having a flat water chamber at the combustion
chamber end, separated from the main part of the steam generator, but connected
up with same by tubes at the bottom and top. This water chamber will be
provided with an aperture for a door or doors as above described, and for the same
purpose, the space between it and the body of the steam generator constituting the
combustion chamber, from which the return tubes carry the gases of combustion.
A sight hole may be provided through this chamber-or through the water space
of the end of the combustion chamber of the boiler last described-for seeing into
the furnace and the state of the fire upon the grate.
"
In a "Cornish " or "Lancashire steam generator arranged to be operated
according to this invention, the gases of combustion are first caused to travel
towards the front and then back through the side flue, and then through internal
flues ;
after which they may be led through other flues.
In cases where steam generators constructed as above described are used for
burning refuse material, or analogous, or like materials, or when desired, they may
be provided with furnaces and parts as above described, or any of them, and
arranged to be worked and operated accordingly.
It is to be stated that different parts, or combinations of parts, under this
invention, may be used, in different steam generators to which they may be
applicable, as well as conjointly as shewn and set forth with reference to the
drawings hereto annexed, the novel features or constructions under this invention
being specifically pointed out or referred to in the claiming clauses concluding the
Specification.
The drawings hereto annexed shew the modifications of our invention; one of
these is shewn in Figures 1, 2, 3 and 4; another in Figures 5 and 6; and the
third in Figures 7 and 8. Of Figures 1 to 4, Figure 1 is a longitudinal
sectional elevation, Figure 2 is a cross section taken half at the line A A and
half at the line B'B Figure 1, Figure 3 is a front elevation, and Figure 4 is a
back end elevation partly in section through the air regenerators at that end.
In Figures 5 and 6, Figure 5 is a longitudinal sectional elevation, and Figure 6 a
front end view. And of Figures 7 and 8, Figure 7 is a side elevation, and Figure 8
an end view.
Referring in the first instance to Figures 1 to 4; the arrangement there shewn
is one where parts of the steam generator, that is the front parts are mostly of
brickwork, the generator shewn being of the internally fired type with return fire
tubes. The furnace flue is designated a; b is the outer shell; c and d are
respectively the front and back end plates, constituting also the tube plates;

page_text: ande are the return tubes, fastened at their ends in the said tube plates c and d.
fare blowers for supplying air to the furnace, the type and arrangement of
blowers shewn being that commonly used in the "Meldrum furnace," i.e. blowers
fastened at or by their heads to a plate g which encloses the back end of the
furnace a, and their bodies disposed horizontally and practically wholly in the
ashpit. is a shoot or hopper connecting the outer shell band furnace a at
the back end of the generator, through which the material to be burned is
introduced into the furnace a. is the dead plate in the furnace, it being disposed
directly beneath the supply shoot h, and so arranged that the material falls aud
remains upon it. jare grate bars of any known suitable kind, but preferably with
small air spaces between them, that is set closely together to suit the use in
connection with them of small fuel or refuse. is a second dead plate between the
end of the bars j and the front of the generator, onto which incombustible matters,
as clinker &c. are moved or worked prior to removal. is the door at the front of
the generator, by means of which access is had to the furnace, and through which
the working of it mainly takes place, it being balanced by weight 1, and worked
up and down through chains as shewn. g' is a door in the plate g at the back end
of the furnace above the dead plate i through which access can be had to the space
above the dead plate i, and d is a similar door in said plate for gaining access to
the ashpit. These two doors may with advantage be of the self closing type with
inclined lugs, commonly used in "Meldrum" furnaces: a similar door m is used
in connection with the front end plate n of the steam generator for gaining access
to and clearing out the ashpit. Over the grate, lining the top of the furnace, is a
brick work arch o supported by flanges o¹ on the sides of the furnace.
tubes
e,
The brickwork, p, at the front of the generator comprises a front and side walls,
with chambers q formed or built in it, on either side, and opposite the nest of fire
the said chambers being in communication with the furnace, from which the
fire gases pass to them to the right and left; while an arch supports the brickwork
between these chambers and that above the passage or doorway leading between
the door and the furnace.
At the back end of the steam generator the air heating portion is disposed.
This comprises boxes s into which the fire gases after leaving the tubes e pass;
chambers t with upper and lower plates t¹, and tubes (2 rising through said
chambers and fixed in plates t¹, through which the gases from the boxes s are led;
a funnel u with a steam-jet nozzle therein acting as an exhausting jet; and a
box v with a front door o covering the front enclosing plate g of the furnace flue a,
blower mouths, and doors g¹ g², and communicating with the interior of the
regenerator chamber t by a tube or conduit w, through which the air heated in and
by the regenerator passes to the box v.
Above the steam generator, a platform a supported on columns y is provided, from
which the material to be burned is charged into the shoot h.
The mode of working, and the action of the different parts of the apparatus will
now be described, it being assumed that the material to be used or burned in the
generator is refuse material as towns' or works' refuse, or the like. Taking it,
then, that the apparatus is in operation, when the material on the grate burns
away and the fire requires making up, dried or baked material at the back end of
the grate upon the dead plate is raked forward, by a suitable tool passed into
the furnace through the doorway -the fire if needing it being first cleaned→
and the fire made up. Then when the fire is in a proper state of combustion the
cap on the shoot h is removed, and material from the platform æ is charged into
the shoot h, so that a fresh body of material will be delivered onto and rest
upon the dead plate i. This freshly introduced material, while resting on the dead
plate i, becomes heated or baked, and volatile gases or vapours and moisture are
thereby driven off from it. These gases or vapours pass along over the burning
fuel on the grate j towards the front of the generator, and the combustible portion
of them, under the influence of the heat of the furnace, assisted by that given off
from the brickwork arch o, and that of the chambers q, becomes completely burnt.

page_text: by the hot free air passing through the fire on the grate. (Or a separate supply
of hot air to the furnace above the grate may be given to effect this purpose.)
These burned gases, with those coming away from the dried or baked burning
material upon the grate j, pass from the furnace into the chambers q, and thence
along the tubes e to the boxes s at the opposite end of the generator. From here
they pass up through the heat transferring tubes 13 of the air heating, or regenerator
chamber t, giving out in this passage their residual heat to them; and then enter
the chamber u² at the base of the chimney u, whence they are removed and
discharged through the chimney u into the atmosphere by the jet of steam delivered
from the nozzle u¹. The fire gases will of course in passing through the furnace
and heating tubes e give up the bulk of their heat to the water of the generator,
that given up to the air heating or regenerating chambers being waste heat.
The whole practically-of the heat of the gases of combustion will not only have
been utilized in the generation of steam and the heating of the air used for burning
the material, but all the combustible portion, both volatile or gaseous an:1 solid, is
completely burned, while the gases or vapours discharged into the atmosphere from
the apparatus are innoxious in all respects.
"
"
In cleaning the fire, clinker and incombustible solid matters are worked down off
the grate onto the front dead plate k, and are removed from the generator
through the doorway, while the ash or dust falls through the grate bars into
the ashpit, and, when required it is removed through the passage or aperture in
the platen, normally covered by the door m, which of course is first removed.
Referring now to the parts for and mode of supplying and heating the air used
to support combustion of the material, and the manner of regulating, and controlling
the draught or conduit of the air and fire gases in the generator, the main means
of supplying such air, consists of steam jet blowers f. These, firstly, cause
the introduction of air into and through the regenerators t. The air enters the
regenerator chambers through apertures t³, at the outside lower part thereof, and
then passes over the hot tubes towards the central upper part of the regenerator,
becoming, in its passage over the heating surface, heated; and it then passes by
the conduit w into the box enclosing the plate in the furnace end, and then
entering the blowers fit is forced into the ashpit. The hot air then passes up
through the fuel on the grate j, and combustion takes place at a high temperature,
while that part of the hot air which passes through the fuel without uniting with
it, is further heated, and effects, as above described, the combustion of the volatile
gases or vapours expelled or coming from the fuel on the grate, and that or those
of a combustible nature coming from the heap on dead plate i.
With regard to the regulation of draught in and through the generator, by having
the forced or plus pressure draught below the grate, and a short chimney to carry
off the products of combustion, to produce a flow of gases through, and pressures
within, the generator which will secure an effective and convenient condition or
state of combustion and action, assistance is given to the gases in their passage
through the tubes of the steam generator and through the air regenerator, by the
creation of minus pressure by the exhausting steam jet in the base al of the
chimney u. By this, firstly, the said assisted passage of the gases is obtained, and
secondly, the pressure in the furnace above the grate is kept at the pressure of the
atmosphere, or slightly below it, and so any outflow of fire gases from the
doorway when the door is opened is prevented, and the working of the fire and
generator by the operator, enabled to be carried on through this doorway without
hindrance or inconvenience.
Regarding now the modification shewn in Figures 5 and 6, in this case no
brick work is used, the whole steam generator being of metallic structure; that is,
the added parts shewn in Figures 1 to 4 at the front of generator, are contained
within the generator itself in this modification. In other respects, however, than
this, the generator is practically similar to that shewn in Figures 1 to 4. As
regards then these differing constructive features, the chambers 9 are in this case
of a "wet" construction, that is, they are made of metal plate built in the shell

page_text: -
of the steam generator, and surrounded with the water thereof, and the doorway or
passage by which communication between the front of the steam generator and the
furnace and ashpit is made, consists of a tubular neck 1, connecting the furnace a and
the front plate of the chamber g with the front end plate c' of the steam generator.
The mouth of this neck is provided with a plate 3 in connection with the face of
which the doors and m fit and work. In this case, the front dead plate kis
provided with apertures, controlled by the valve k', moved to and fro from outside
through a rod k². By these apertures hot air may be supplied from the ashpit to
the gases or vapours coming off from the fuel in addition to that passing through
the grate bars and fuel, to effect their combustion.
In cases where towns', house, works', or like refuse is to be burned, the invention
provides a means of thoroughly destroying such refuse, and at the same time
generating steam, utilizing the largest possible proportion of heat to be obtained
from the material in the generation, the said destruction being such that no noxious
or offensive gases pass from the apparatus. The invention, therefore, provides a
destructor-steam-generator, efficient in all respects, and with it all, at a minimum
expense, both in first cost, and subsequently in labour.
In the constructions or arrangements of steam generators shewn, when it is
desired, they can be fired or stoked through the front door 1, through which the
fuel can be thrown onto the grate, and in this way a sudden demand for steam, as
sometimes happens, as in connection with electricity supplies for electric lighting,
may be promptly met.
In cases where it is desired to burn fuels other than refuse, the steam generator
described may be used with advantage, since steam may be generated most
economically, and the generator used with efficiency, as a simple steam raiser, when
fired with any other kind of fuel.
In the modification shewn in Figures 7 and 8, the shoot or hopper h through
which the material is charged onto the grate, or dead plate i thereof, is disposed
outside, at the back end of the steam generator, and the air heating parts or
regenerators t are placed below the waste gas boxes s, in lieu of above thein as in
the generators shewn in the other drawings, and the "waste
through them, and passing away by a suitable flue below.
"
gases brought down
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is :-
1. A steam generator constructed and adapted to have fuel supplied in bulk to
the furnace thereof; to drive off the volatile matters and vapours from the said
material by a baking or heating action; to burn the said material so baked or
heated upon a grate by moving it into same and passing air through it; to burn
the said vapourized gases and fumes; to utilize the heat of the products of com-
bustion by passing them over heating surface; and to heat the air used to support
combustion of the material by the "waste" gases after leaving the water heating
surfaces of the generator; substantially as and for the purposes herein set forth.
2. A steam generator comprising a furnace disposed within a shell, and return
heating tubes or conduits, a grate one end of which is adapted to receive the
fuel, where it is heated or baked and volatile matters expelled, and having at
the opposite end a door; operating substantially as and for the purposes described.
3. A steam generator comprising, a shell with a horizontal flue or furnace
therein and return tubes through which the gases of combustion pass; a grate or
fuel bearer in said furnace; means such as described at one end for charging the
fuel onto one end of said grate in bulk; and a door at the opposite end of said
furnace by which the fuel can be worked forward from the bulk over said grate :
substantially as set forth.
-
4. A steam generator comprising a shell; a furnace flue and return tubes
therein through which the fire gases pass; a grate or fuel bearers in said furnace,
with means for introducing the fuel in bulk onto one end; means at the opposite

page_text: end through which the fuel may be worked; and an air heating device or
apparatus at the back end of the generator, the surfaces in which are heated by
the "
waste gases, and heat the air delivered into the ashpit to support combustion
of the fuel.
"
5. In a steam generator, a furnace having at one end a dead plate onto which
the fuel is charged in bulk, and whereon it is heated or baked; a plate at the
opposite end of said furnace, onto which clinkers or unburned matters may be drawn
for removal; a door for gaining access to the furnace in connection with same ;.
and grate bars or bearers between said plates, and on which the combustion of
the fuel or material burned takes place; said fuel being adapted to be worked from
one end and over the grate to the other; substantially as described.
"
6. The arrangement in a steam generator having return tubes or conduits, of
means for introducing air to support combustion of the fuel therein, and regulating
the draught, comprising in connection with the furnace, steam jet blowers by which
air is forced under pressure in the ashpit at one end; a door at the opposite end
through which the fuel is worked on the grate; an air heating apparatus at the
end at which the blowers are arranged, heated by the "waste
gases from the
return tubes or conduits of said generator; and an exhausting jet in the chimney
on the discharge side of said air heating apparatus by which the flow of fire gases.
through the said tubes or conduits and the said air heater is assisted, and the
pressure above the fuel on the grate maintained at that of or below that of the
atmosphere; substantially as and for the purposes described.
"waste
7. In a steam generator having a shell, an internal furnace, and return fire
tubes, the arrangement at one end, of an air heating apparatus, heated by the
"heat of the gases of combustion, steam jet blowers for forcing air into the
ashpit of the said furnace arranged as described and shewn, and a conduit or
chamber connecting said air heating apparatus and blower inlets by which air is
drawn through said air heating apparatus, and conveyed to said blowers and
forced thereby into the ashpit; and at the opposite end, a doorway and door for
gaining access to said furnace; substantially as set forth and shewn for the purposes.
specified.
8. The steam generator having its parts arranged, and combined, and adapted
to operate, particularly as set forth with reference to Figures 1 to 4; Figures 5
and 6; and to Figures 7 and 8, respectively, of the drawings.
1
Damban 1001
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicants' Agents.