IMPROVEMENTS IN REVOLVING FURNACES, AND IN APPARATUS CONNECTED THERE- WITH
Year: 1875

page_text: LETTERS PATENT to Thomas Russell Crampton, of 4, Victoria Street,
in the City of Westminster, for the Invention of "IMPROVEMENTS IN
Sealed the 13th August 1875, and dated the 3rd March 1875.
PROVISIONAL SPECIFICATION left by the said Thomas Russell
Crampton at the Office of the Commissioners of Patents, with his
Petition, on the 3rd March 1875.
I, THOMAS RUSSELL CRAMPTON, of 4, Victoria Street, in the City of
Westminster, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN REVOLVING FURNACES, AND IN APPARATUS CONNECTED THERE-
WITH," to be as follows:-
:-
A part of this Invention relates to improvements in the wearing rings
of revolving furnaces. In those revolving furnaces where water is used
to cool the exterior of the same and to diminish the distortion of the
wearing rings or surfaces forming a joint between the revolving and
non-revolving portions of the furnace. The rings as generally employed

page_text: are attached either in complete rings or in segments of considerable
length as compared with their breadth and thickness. As these rings
and segments wear out they have to be replaced at considerable
expenditure of time and money. To reduce these elements of expenditure
I attach small pieces of cast iron, chilled or otherwise, of steel, wrought
iron, or other suitable material to those parts subject to wear, fixing
them on to the water protected parts, but without their being in direct
contact with the water in the casing of the furnace. These small
wearing surfaces should be about three inches square more or less, and
about one and a half inches thick, or of other dimensions, so that the
wearing ring will not become injuriously distorted by contraction and
expansion to such an extent as to practically destroy the true plane or
surface of the joint. To illustrate this wearing surfaces or rings when
not in one piece are generally formed of segments, say 4 to 6 in number,
and about 2 to 3 feet long, and are bolted or otherwise secured to
the casing, but it is difficult to so secure their ends as to keep them in
one plane, or prevent them breaking through the contraction and
expansion to which they are subjected, but when these segments are
small as described the contraction and expansion to which they are
subjected is not of that extent as practically to destroy the truth of the
joint.
In some cases the small pieces composing the rings may be applied
around the junction between the revolving and non-revolving parts of
the furnace in such a manner as to expose a portion of the piece to the
direct action of the water in the water casings.
In order to prevent the air from accumulating in the annular water
casing surrounding a revolving furnace chamber no matter in what
position the chamber may be, and in order that no part of the revolving
chamber can ever become uncovered by water I make the whole or a
portion of the outer casing considerably larger in diameter than the
inner casing, and lead off a number of pipes from points near to and at
distances around the outer circumference of the annular water casing to
carry off air and water from it. The pipes all pass to a central cock, by
which the passage through them is closed, except when their outer ends
are above the top of the inner casing. Water is supplied continuously to
the water casing through a passage passing centrally through the cock
above mentioned.

page_text: In place of making the whole or a portion of the water casing con-
siderably larger in diameter than the inner casing pipes may be carried
out from it at distances around its circumference to effect the same
object.
For the purpose of effecting a continuous renewal of the lining of
revolving combustion chambers which are constructed with a surrounding
water casing, and which are heated by the combustion of powdered fuel
and air, and from which the products of combustion pass away to be
utilized in boilers or other apparatus requiring to be heated. I fix pegs
or projections into the interior casing, by preference projecting into the
water contained in the water space on the one side, and into the furnace
lining on the other; the pegs may be either solid or hollow, so that
the water can enter into them if desired, and be of any convenient form
or size.
The furnace is lined in the first instance with fire-clay bricks or other
suitable material, and when this material becomes displaced or worn
away from any cause and so exposes the casing or the pegs, and when
such exposed or bare places pass under the slag produced by the melting
of the mineral matters and dirt in the fuel which forms a bath at the
bottom the slag becomes chilled and sets on to the casing and pegs. In
a similar manner the vertical face of the chamber is kept lined by a
portion of the slag being carried round and running down over such
faces and chilling and setting upon the projections or pegs there formed.
Thus, a self-acting process of relining is established.
When the fuel employed does not contain sufficient mineral matters or
dirt to produce enough slag to keep up the process of relining any
suitable refractory material, such as fire-clay, oxide of iron, or others
may be thrown in for the purpose of producing slag; or in cases when
the slag produced from the dirt and coal is not of a sufficiently refractory
character refractory material may be similarly thrown in from time to
time.
Instead of pegs or other projections fixed to a double water casing
coils of pipes through which water circulates may be employed, with or
without projections upon them, and the slag be made to cover and
surround and set on such coils in a similar manner as on to the pegs or
other projections previously described. The surplus slag is caused to run

page_text: off over the lip of the furnace formed for the purpose where the revolving
portion joins the fixed portion of the apparatus.
The water used for cooling may be utilized for supplying boilers or for
other purposes, and in some cases the water casing of the revolving
chamber may be in direct communication with the water in a steam
boiler, so as to form part of the boiler.
Where powdered fuel and air are employed for heating revolving
furnaces, and where the powdered fuel is fed from a supply or feeding
chamber by feeding apparatus to revolving furnaces I convey the
powdered fuel as it is delivered from the pulverising apparatus to such
feeding chamber by means of creepers or by similar apparatus carried
over or near to a reservoir, and I attach a valve or slide to the bottom
of the feeder trough, through which a communication may be opened
with the reservoir. In the feeding chamber I mount a revolving vertical
shaft with arms standing out from it to act as stirrers. When the lovel
of the fuel rises above the stirrers it comes into contact with a hanging
float or plate which is in connection with the valve or slide above
mentioned, and by moving this float or plate opens the valve and allows
the powdered fuel coming from the pulverising apparatus to fall into the
reservoir; as the fuel descends in the feeding chamber the float or plate
falls and again closes the valve; the powdered fuel will then again be
supplied to the feeding chamber.
When the pulverizing apparatus is not in action and the fuel in the
reservoir is required to be conducted to the feeding chamber the fuel is
conveyed from the bottom of the reservoir by means of screws or a
Jacob's ladder or other lifting apparatus into the trough above the
reservoir, and thence to the feeding chamber, any surplus fuel being
allowed to fall back into the reservoir, as above explained.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Russell Crampton in the Great Seal Patent 30
Office on the 3rd September 1875.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of March, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Thomas Russell Crampton,
Her special license that I, the said Thomas Russell Crampton, my
executors, administrators, and assigns, or such others as I, the said
Thomas Russell Crampton, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN REVOLVING FURNACES, AND IN
APPARATUS CONNECTED THEREWITH," upon the condition (amongst others)
that I, the said Thomas Russell Crampton, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
.
NOW KNOW YE, that I, the said Thomas Russell Crampton, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say:-
In the Specification of my Patent of 12th November 1873, No. 3687,
which is based on improvements constituting an Invention for which I
obtained a prior Patent, dated March 28th 1872, No. 931, I describe
means of connecting to revolving furnaces wearing rings which are
in immediate contact with the water in the casing, or through which
water is made to circulate.
The present Invention relates to further improvements in the wearing
surfaces which form a joint between the revolving and non-revolving
portions of the furnace. Rings have hitherto been employed which are
attached either in complete rings or in segments of considerable length
as compared with their width and thickness. As these rings and
segments wear out they have to be replaced, involving considerable

page_text: expenditure of time and money. To reduce these elements of expendi-
ture I attach small pieces of cast iron, chilled or otherwise, or of steel,
or wrought iron, or any other suitable material to those parts subject to
wear, fixing them on to the water protected parts. These small wearing
surfaces should be about 3 inches square, more or less, and about 1
inches thick, or any other small dimensions not exceeding 6 inches in
length, so that the wearing ring will not become injuriously distorted by
contraction and expansion to such an extent as to practically destroy the
true plane or surface of the joints. Wearing surfaces or rings when not
in direct contact with water have been proposed to be formed either in
one piece or of segments, say 4 to 6 in number, these segments in
furnaces of the size usually constructed heretofore are about 2 feet to
3 feet long and are secured to the casing, but it becomes extremely
difficult to so secure the ends as to keep them in one plane or to prevent
them breaking in consequence of the contraction and expansion to
which they are subjected. To the use of such large pieces I lay no
claim, as such pieces cannot be used without considerable leakage.
This leakage it is my object practically to prevent, at the same time
that I am able economically to replace the portions of the rings as they
become worn. I therefore use pieces of metal of such small size, as
described, so that they can expand and contract within themselves
without practically destroying the truth of the main joint formed by
the combination of the several pieces making what is practically a
ring.
In some cases the small pieces composing the ring may be inserted in
such a manner as to expose a portion of the piece to the direct action of
the water in the casing.
These improvements are carried out as follows:-
―:
Figure 14.-A is a section of a small wearing face let into a dovetail
groove B formed in the metal constituting the water casing C of the
furnace. A portion of one side of the dovetail groove B (see Figures 10
and 11) of the width of one or several wearing pieces is cut away at D
so as to allow each piece to be inserted and slipped round, the last one
being secured in its place by a piece of angle iron d fastened to the
water casing. The same may be secured by any other convenient means.
The small wearing pieces may be formed at an angle, as shewn at N
(Figure 11) or radially as M (Figure 11), or they may be of any other
suitable form than those shewn.

page_text: Figure 15 shews another mode of fastening the small wearing pieces.
A is a section of the small wearing piece let into a dovetail on one side,
and secured by a bar B to the water casing fastened by a bolt C forcing
the wearing piece on to the face of the casing and into the dovetail.
More than one wearing piece may be secured by one bolt.
Figure 16 shows another mode of fastening. Attached to each
wearing piece is a small bracket B secured by a bolt C to the water
casing.
Figures 10, 11, 12, 13, shew the small wearing pieces secured to
separate rings through which water circulates, which rings are attached
to the water casing of the furnace. The pieces are secured to such rings
in a similar manner to that shewn in Figures 14, 15, or 16.
Figures 17, 18, shew the small wearing pieces A turned on one side
at B and fitted watertight into holes bored in the water casing. In this
case the pieces are brought into direct contact with the water. In all the
other cases it will be observed that where they are not so in direct
contact they are placed in juxtaposition to parts of the water casing
formed of one thickness of metal which are primarily cooled by the
water, and so impart a cooling and protecting action to the pieces.
The wearing pieces on their faces may be of the form previously
described, and are secured by being driven tightly into their places, or
they may be secured to the water casing (see Figure 19) by screwing up
a bar D by a bolt E against the wearing piece A, or by other convenient
arrangements, or the small wearing pieces may be circular in section
and be screwed into their places. To allow the water to come near to
the wearing surface the pieces may be made hollow, as shown in
Figure 17. Such pieces may also be secured to a separate ring through
which water passes, and as described in Figures 10, 11, 12, 13.
All the above modes of forming wearing rings composed of small
pieces are applicable not only to the revolving parts of furnaces, but to
those non-revolving portions coming in contact with them.
It will be observed that in all the ways above described of securing
the several small wearing pieces of the wearing rings the pieces are let
into grooves or holes formed wholly or partially in or by the metal
forming the water casing, so that the cooling effect of the water is
always brought to bear upon the wearing pieces either directly or
indirectly through a single thickness of metal forming the water casing

page_text: with which the wearing pieces are in contact. I do not claim the
mechanical means or parts used for fixing the wearing pieces in their
respective positions.
'
The object of another part of this Invention is to prevent the air from
accumulating in a revolving chamber, whether cylindrical, or globular,
or of other form, no matter in what position the chamber may be, so
that no part of the inner casing can ever become uncovered by water
whether it is in motion or at rest. I attain this object by making tho
whole of the outer casing considerably larger than the inner casing, or
by making an enlargement all around the water casing at any con-
venient point or by making projections formed of pipes, the water being
supplied to the casing by a central cock of suitable dimensions and
construction, às herein-after is more particularly shewn.
In the Specifications of the two Patents granted to me March 28th,
1872, No. 931, and November 12th, 1873, No. 3687, various means
of applying water for cooling revolving furnaces are described, the
former states that water is introduced into revolving furnaces centrally
through a cock or bearing or through the axis of rotation. The
means by which this principle is carried into practical effect is sub-
stantially described to be in the following manner:-A bearing or
cock is attached to the revolving chamber at any convenient distance
from its end in a line with its axis on which it turns, revolving in a fixed
shell. The water is described and shewn as entering this central cock
or water apparatus through a fixed pipe attached to its periphery, com-
municating with an annular chamber or channel also on or near its
periphery, from thence it passes by conduits or channels into the water
spaces of the revolving furnace. After traversing the water spaces it
makes its exit through another annular space or channel on the outside
of the cock, and thence passes out through a pipe on the periphery of
the same apparatus.
Another mode is described of admitting to and discharging the water
from the furnace casing. In this case instead of the water entering and
leaving at the periphery of the revolving cock or apparatus, it is caused
to enter through a pipe fixed to the ground which is connected by a
simple revolving union joint to the revolving furnace, the line indicating
the central axis passing through the centre of the water in the central
pipe. The water after circulating through the water spaces makes its
exit at any convenient point from openings made in pipes at or near the

page_text: outside of the furnace, or in other convenient positions falling into
channels near the ground.
After describing practical means of effecting the passage of the water
centrally through a cock or axis of rotation, my said Specification states,
any mode may be adopted for causing the water to pass into the water
spaces of the combustion chamber, so that the main features of its
passing centrally through a cock, bearing, or union joint be maintained
as mentioned. In these arrangements no special provision for the regular
and continuous discharge of air which might accumulate in the water
spaces of the furnace was made, but in the Specification of the Patent of
November 12th, 1873, No. 3687, means are described by which the air
may be caused to escape intermittently.
In the Specification of a Patent granted to one Bedson, and dated
May 14th, 1872, No. 1469, it was proposed to use apparatus which is a
modification of that described in the Specification of my said Patent of
March 28th, 1872, No. 931. In that apparatus the outside of the
cylinder has attached to it a casing forming a water space, to one side of
which is attached an annular water ring communicating with the water
casing of the furnace, and practically forming part of and revolving with
it. Round its periphery an annular shell or ring is fitted water-tight.
The stream of water enters the annular shell by a pipe, passes through
apertures into the water space communicating with the water casing, it
traverses this, and makes its exit through a similar cock or water
apparatus.at the other end.
It is further stated in the said Specification of Bedson that single-
acting apparatus can be employed, into which the water enters at the
bottom and passes out at the top, but in neither case are provisions made
for the continuous escape of accumulated air.
The part of my Invention relating to the removal of accumulated air
is carried out in the following manner :-Figures 3, 4, and 5 are sections
of the water cock. The water passes into the cock at A, and by means
of an annular passage x into the central passage a, a, thence into a
pipe B. Round the central passage a are five other passages of equal
area, in direct communication with the five pipes C, Figure 5. The
outlet passage D in the shell of the cock (see Figure 3) is made equal in
width to one passage with an intermediate space or bridge; it is there-
fore clear that in whatever position the moveable part may be, an opening

page_text: equal to the area of one passage must be open to the outlet D. In a
certain position of the cock two of the five passages may be open to the
outlet; half of each passage however will then be closed, and as the
cock turns one passage will be gradually opened, and the other will be
gradually shut. More than two passages cannot be open at the same
time.
Figures 6 and 7 shew the water casing of a revolving chamber. The
water enters and leaves the casing in the following manner :-It enters
at A, passes through the central passage into the pipe B, and is dis-
charged inside the water casing at r. It then passes through the casing
back towards the points G*, G*, (Figure 6), enters the pipes C, and
passes through one or two of the five passages into the shell of the cock,
and out at D.
A horizontal line 8, 8, drawn above the top of the inner casing N
indicates the lowest level to which the water should ever be allowed to 1
fall. To gain this object the two outlets G, G, in the position of the
furnaces, as shewn in Figure 6, are above this level, and any more air
accumulating than already exists in the casing must escape. This
position at the same time determines the size of the outer casing M of
the furnace, as it must be made large enough to embrace the two pipe
outlets G, G.
It is obvious that by making the outer casing M. large enough 4 pipes
or even 3 pipes may be sufficient to carry off the air and water.
Any other possible position of the furnace cannot be more unfavorable
than that shewn in Figure 6, the most favorable position being when 2
one of the five pipes c is vertical, when the pipe outlet G will be just
below the outer casing, and nearly all the air accumulated in the casing
will escape.
Figure 8 shews a revolving chamber, with an enlargement E, E, being
made at one end, which allows the pipe outlets G to be brought so far 3
above the top of the inner casing as will attain the same object as
mentioned in connection with Figures 6 and 7.
Figures 1 and 2 shew another mode of carrying out the same idea,
projections being formed of pipes to obtain a sufficient height of the pipe
outlets G above the inner casing.
3

page_text: Figures 6 and 7 shew a revolving chamber or furnace with a
common union joint B of any convenient dimensions at one end, through
which the water is introduced into the water casing, and is delivered at
its opposite end by means of a pipe C revolving with the furnace. A
number of holes placed on the outside casing at certain distances apart
allow the water and the air accumulated at the top to escape from the
furnace casing uninterruptedly. For this reason the distances between
these outlets must be determined in the manner indicated and described
in relation to Figures 1, 2, 6, 7, 8. To these outlets I attach cocks G, G,
which are arranged in the following manner:-A cam formed guide H
(Figures 6 and 7*,) is placed all round and parallel with the furnace,
and fixed to the ground. Its distance from the furnace is increased
between the points R and S, the ends of the more distant portion being
gradually curved into the main part. The increase must be sufficient to
cause the full opening of the cocks G, G. Each cock is opened and
closed by a lever fixed upon its plug, at the end of which lever are two
small rollers which grasp the guide H. Each cock as it passes in
rotation is opened at R, remains open until it comes to S, and is then
closed again, or if the furnace turns in the opposite direction it is opened
at S and closed at R.
Instead of cocks valves may be employed, and they may be opened by
the guide H, and closed by the same, or by springs or other contrivances.
Instead of the guide H various other convenient means may be adopted
for automatically opening and shutting tho cocks or valves. By this
arrangement the water casing will always remain full of water up to the
level indicated by the dotted line, even when the furnace is not at work,
but this automatic arrangement for opening and closing the cocks may
be dispensed with, and the cocks be left open at all times all round the
furnace, or the cocks may be dispensed with and mere openings used.
In this case also the air will be free to pass off through the cocks or
openings which happen to be at the top. In all cases the cocks or outlet
openings must be so situated that one or more of them shall of necessity
be at all times above the level of the top of the inner chamber. These
latter arrangements would however require attention to retain sufficient
water in the casing. Suitable arrangements are made for conducting
the water as it leaves these outlets into channels on the ground.
It should be observed that the number of openings described is the
minimum that should be employed, and that their number may be

page_text: increased, the object being that there shall at all times be one or more
openings above a horizontal line drawn over the top of the inner
casing.
rds
Figure 20 shews a large cock A placed on the furnace, and of about
2/d its diameter. The cock is practically an enlargement of the cock
described in the Specification of my Patent of March 1872. B is a water
casing, to one side of which is fixed a hollow ring C provided with a
circular packing box D. The gland E is formed of two parts, each
consisting of 4 portions of rings, which are drawn together by bolts.
In the packing box is a stationary hollow ring F furnished with a pipe K
for the supply of water. At g are perforations forming a communication
between the annular chamber F and the annular chamber C leading
into the furnace. As the furnace revolves water flows through the
pipe K, the annular chamber F, and the perforations G. When this
arrangement for the introduction of water into the water casing is
adopted the arrangements described in reference to Figures 6 and 7ª for
allowing of the continuous escape of water and air may also be made
use of.
Figures 21 and 22 shew a cock so arranged that the water passes
through it into the water casing, traversing the same, and making its
exit through the same cock. This cock is also practically an enlarge-
ment of that described in the Specification of my former Patent, dated
28th March, 1872, No. 931. The water enters at the pipe A and passes
into an annular channel B in the fixed shell C, and through the fixed
pipe D into the water casing, which it traverses, and passes out through
holes or outlets E placed all round the furnace into the shell at F and
out at G, together with any air that may have accumulated at the top of
the water casing. A flange on the revolving part of the cock with set
screws or springs acting against a washer allows the shell to be tightened
up when required. If the diameter of the cock is decreased or the
diameter of the furnace enlarged divisions must be made in the annular
space E, as shewn by the dotted lines at Figure 21, and pipes must be
led from the outer circumference of the water casing into cach division
of the space E, so that the cock shall then act in the manner described
with reference to Figures 3, 4, 5, 6, and 7. Or the cock may be arranged
with only one annular space, through which water is admitted into the
water casing, as previously described in reference to Figure 20, and the
water may be discharged, together with the accumulated air, through

page_text: openings on the outside of the water casing, as described in reference to
Figures 6 and 7ª.
When furnaces are constructed of say a globular form, which has
before been proposed, the outlets for the escape of the air with the water
should be placed on the largest diameter, the revolving cocks for the
admission of water into the casing may be placed on any convenient
portion of the furnace, as may be found most convenient, but the smaller
they can be kept in diameter the less friction and the less liability to
leakage.
a, Figure 23, is a globular revolving furnace, B are cocks for the
regular outlet of water and air arranged as previously described in
reference to Figures 3, 4, and 5; A, B, C, D, shew the position that the
inlet cocks may be situated.
Another part of this Invention is for the purpose of effecting a self-
acting process of lining revolving combustion chambers constructed with
a casing through which water circulates heated by powdered fuel and
air, the products of combustion passing from this chamber to be utilized
in boilers or other apparatus requiring to be heated. Pegs or projections
are fixed into the interior casing, by preference projecting into the water
on the one side and into the furnace on the other. The pegs may be
made either solid or hollow, so that the water can enter into them if
desired, and of any convenient form and size. Sufficient space is left at
the lower part of the joint between the revolving and non-revolving
portion of the furnace to allow the surplus slag to flow continuously
away.
Figure 8 shews a revolving combustion chamber M with a casing N,
through which water circulates; m, m, m, are pegs or projections; R, the
apparatus in which the heat is to be utilized.
The furnace is lined in the first instance with fire-clay bricks or other
suitable materials, and when this material becomes worn away or falls off
and exposes the metal of the casing the slag produced by the melting of
the mineral matters and dirt in the fuel which forms a bath at the bottom
will, when such exposed or bare places pass under it, chill and set on such
places through the cooling action of the pegs or other projections. In a
similar manner the vertical face of the chamber is kept lined by a portion
of the slag being carried round and run off over the face and chilling
and setting on the pegs and projections there formed, thus a self-acting

page_text: process of relining is established. When the fuel employed for heating
does not contain sufficient matters or dirt to produce enough slag to keep
up the process of relining any suitable refractory materials, such as fire-
clay, oxide of iron, or others may be thrown in for the purpose of pro-
ducing slag. Instead of pegs or other projections fixed to a double water
casing, coils of pipes, through which water circulates, may be employed,
and the slag be made to cover and surround and set on such coils in a
similar manner as on pegs and other projections. The surplus slag made
runs over the lip of the furnace (a) where the revolving portion joins the
fixed portion of the heating apparatus, the lower part of the opening
being made large enough for the purpose, as before stated.
The water used for cooling may be utilized in supplying boilers or for
other purposes, and in some cases the water casing of a revolving
chamber may be in direct communication with the water in the boiler.
No claim is mado with reference to the foregoing other than to the
means provided for the continuous escape of the surplus slag and the
maintenance of the slag at a constant level.
Where powdered fuel and air are employed for heating, revolving, or
other furnaces and where the powdered fuel is fed from a supply or
feeding chamber by feeding apparatus to such furnaces I convey the
powdered fuel as it is delivered from the pulverizing apparatus to such
feeding chamber by means of a screw or creeper, or by similar apparatus
carried over or near to a reservoir and I attach a valve or slide to the
bottom of the feeder trough through which a communication may be
opened with the reservoir.
In the feeding chamber (A, Figure 9) I mount a revolving vertical
shaft B with arms C standing out from it to act as stirrers; when the
level of the fuel rises above the stirrers it comes into contact with a
hanging float or plate D which is connected by a wire d passing over
grooved wheels e, e, with a counterweight f and levers g, g, attached to;
the spindle on which the wheel is fixed, or by other suitable connection
with the valve or slide E above mentioned, and by moving this float or
plate by the fuel coming in contact with it, by the action of the stirrers
the valve E opens and allows the powdered fuel passing along the
trough F from the pulverizing apparatus to fall through the shoot G;
into the reservoir H. As the fuel descends in the feeding chamber
.

page_text: below the arms C the float or plate D falls and closes the valve E, the
powdered fuel will then again be supplied to the feeding chamber A.
When the pulverizing apparatus is not in action and the fuel in the
reservoir H is required to be conducted to the feeding chamber A, the
fuel is conveyed from the bottom of the reservoir H by any of the
ordinary well known means of screws or a Jacob's ladder or other
lifting apparatus into the trough F between the valve E and the
pulverizing apparatus above the reservoir and thence to the feeding
chamber A, any surplus fuel being allowed to fall back into the reservoir
H as above explained, when the fuel is conveyed direct from the
pulverizing apparatus. The coal passes from the bottom of the feeding
chamber A into feeders I, I, for supplying the furnaces, those shewn
are similar to those employed by me in other cases and are now well
known, or other suitable kind of feeders may be employed for the
purpose, such apparatus forming no part of this improvement.
Having now described the nature of my Invention and the manner
of performing the same I would have it understood that I claim,-
First. The use of small pieces of metal herein-before called wearing
pieces when used to form wearing surfaces, in the manner and for the
purposes herein-before described, or any mere modification thereof.
Second. I am aware that it has been proposed to use revolving
puddling or other revolving furnaces subjected to great heat with a
double water casing on all sides, the water being introduced by cocks or
apparatus consisting of stationary and revolving annular parts or rings,
and arranged so as to comprise an annular passage or channel for con-
ducting the water to the furnace casing.
In the Specifications of my Patents of 28th March, 1872, No. 931, and
12th November, 1873, No. 3687, and G. Bedson's, 14th May, 1872,
No. 1469, forms of apparatus of the character above referred to have
been described and shewn in Drawings, I therefore make no claim to
those forms of apparatus but what I claim is,—
The arrangements of parts as herein combined for effecting the con-
tinuous discharge of air from water casings of revolving furnaces, in the
manner and for the purposes substantially as herein-before described in
reference to Figures 1, 2, 3, 4, 5, 6, 6^, 7, 74, 20, 21, 22, and 23, or any
mere modification thereof.

page_text: Third. I claim the use of revolving combustion chambers, constructed
as shewn in Figure 8, when the means herein-before described for
providing for the overflow of surplus slag and for maintaining the slag
at the required uniform level, are employed substantially as herein
described.
Fourth. I claim the use of apparatus for regulating the supply of
powdered fuel constructed in the manner and for the purposes sub-
stantially as herein-before described in reference to Figure 9 or any mere
modification thereof.
In witness whereof, I, the said Thomas Russell Crampton, have
hereunto set my hand and seal, this First day of September in
the year of our Lord One thousand eight hundred and seventy-
five.