Improvements in Furnaces and Drying Apparatuses having a Movable Bed for Ceramic and other Products.
Year: 1898

page_text: Date of Application, 5th Oct., 1898
Complete Specification Left, 15th June, 1899-Accepted; 30th Sept., 1899
PROVISIONAL SPECIFICATION.
Improvements in Furnaces and Drying Apparatuses having a
Movable Bed for Ceramic and other Products.
I, HENRI STURM, of 18, Rue Mogador, Paris;. in the Republic of France,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object certain improvements in ceràmic furnaces and
drying apparatuses having a movable sole, said improvements consisting in com-
bining the sole or movable annular chamber constituting the main element of the
furnace or drying apparatus, with a wall, casing or fixed sheathing, against
which said sole or movable annular chamber revolves, being suitably supported
by means of an arrangement of pivots or rollers, sand baths or other like devices
being employed for preventing the escape of the warm air or the products of com-
bustion, and openings or ports being formed to give passage to the air or pro-
ducts of combustion according to whether it is a question of a drying apparatus
or of a furnace.
In order that the object of the present application may be more clearly under-
stood, I will now refer to the accompanying drawings, in which:
Figure 1 is a sectional elevation of a furnace arranged in conformity with my
invention having a sole or bed mounted on a pivot, the section being taken on
the line A Z B of Figure 3;
Figure 2 is a partial section of the said furnace made on the line C-D of
Figure 3, passing through the furnace;
Figure 3 is à sectional plan view of the said furnace made at different levels,
the parts between the radii K L, M P, R, S, and T U representing a plan view
from above; the part between the radii M P and R S representing a horizontal
section made on the line N-0 of Figure 2; the part between the radii T U
and VX representing a horizontal section taken on the line I-J of Figure 1;
the part between the radii V X and Q Y a horizontal section made on the
line G-H of Figure 1 and finally the part between the radii Q Y and K L repre-
senting a section made on the line E-F of Figure 1;
Figure 4 a sectional elevation of a furnace of the same kind having a sole
mounted on bevel rollers, the said section being made on the line A-Z-B¹ of
Figure 5;
Figure 5 a partial sectional plan view of the same figure at different levels, the
part between the radii K Z and M 7 representing à plan view from above the
furnace, the transverse girders or beams being supposed to be removed; the part
between the radii K¹ 7, T' 7' representing a horizontal section of the same made
on the line GH" of Figure 4; the part between the radii M' 7', S¹ Z' repre-
senting a horizontal section of the same made on the line A"-B" of the same
figure; the part between the radii Z'S' and Z¹ B¹ representing a horizontal section
made on the line C-D" Figure 4; the part between the radii Z¹ B¹ and Z¹ L'
representing a horizontal section made above the plane of the support rollers,
and finally the part comprised between radii Z' T and Z' L' a horizontal section
inade on the line E-F" Figure 5;

page_text: bed 1 and the internal wall 2 of the furnace forms a very appreciable advantago
from the point of view of charging certain products which require to be better
supported than they are in the case of an ordinary furnace with movable bed.
The bed 1 of the furnace is hollow and the products of combustion when it is
a question of a furnace fired with a naked fire pass partly beneath the said bed as
shown in Figures 2 and 4 in order that the bottom of the articles may be baked
or fired simultaneously with the upper part. In order therefore to ensure the
uniform baking or firing, the hollow part 16 of the bed may be supplied with
combustible which ignites as soon as it approaches the zone of baking and pro-
duces the desired result. The external fixed wall 11 of the furnace contains the
furnace or furnaces 17 as well as the breech 18 or door serving for effecting both
the charging and discharging of the furnace which facilitates its working.
On the other hand I arrange below the hollows of the bed, properly so called,
a hollow chamber 19 communicating with the exterior by suitable openings 20
and in which I place quicklime or any other suitable hydroscopic substances
intended to absorb the vapour which is given off when the products have been
newly placed in the furnace, which as a rule causes inconveniences and difficulties
in the baking. This substance is dehydrated again after each passage through the
zone of high temperature.
Small flues 21 arranged vertically or horizontally in the interior wall 2 of the
furnace and closed by means of suitable valves or plugs may as required serve
either as flues for assisting the combustion or as peep holes or charging hoppers
for introducing in case of need additional fuel if by chance that inserted by
the charging hoppers was not sufficient. This arrangement of furnace is com-
pleted by a chimney 22 having a register 24 serving for allowing the products of
combustion to escape, and an arrangement of doors 23 serving to insulate, from
the other parts of the furnace, the part where the charging and discharging of
the articles to be baked is effected.
In order to avoid deformations of the internal fire clay lining 2 and to allow
the free expansion of this interior lining, I form it by means of bricks 26 (see
more particularly the horizontal section in Figure 3 made on the line E-F of
Figure 1) which engage or fit one into another and which may be placed dry and
without too much compression at the joints in order to allow the free expansion
of this lining. When there are two linings 2 and 25 as shown in Figures 1, 2
and 3 it is preferable not to connect these two linings together in order to avoid
deformations of the masonry arising from the greater expansion of the masonry,
of the lining 2 than that of the lining 25.
In order to allow the working of the furnace to be seen it is advisable to
arrange peep holes such as 27 (Figures 1 and 2) at suitable distances apart enabling
the progress of the baking to be followed in order to allow of its being regulated
as required.
The revolving bed such as hereinbefore described may be supported in various
ways. In the case shown in Figures 1, 2 and 3, the whole of the bed 1 and the
interior wall and of the cover 3 is supported by a metallic framework 4 con-
nected with a central shaft 5 which is terminated at its lower part by a pivot 6
revolving in a foot step 7, at the bottom of which is a disc of steel 8, and at its
upper part by a journal 9 revolving in a roller bearing box 10 suitably arranged
in the rafters of the roof and forming a device for guiding.
In the case shown in Figures 4, 5, 6, and 7 the whole of the bed 1 and the
interior wall 2 travel on bevel rollers 30 which in turn travel on a suitable
track 31. In this case the pivot constituting the axis is dispensed with, and the
lower part of the apparatus is consolidated by means of a framework 32 and hori-
zontal drawbars 33 of suitable length capable of being adjusted as required, the
whole fastened together by collars 34 and 35 capable of revolving on a central
vertical shaft 36 solidly mounted in the ground. The cover 3 of the furnace,
which is here fixed, is supported by a series of posts 37 on which are supported

page_text: tie bars 38 and 39 serving to consolidate and sustain a ring or crown 40 forming
the internal armature of the ceiling.
At part of its length in the part of the furnace where the cooling of the burnt
or baked products is effected (the part comprised between the radii M' Z
and SZ) the roof or cover 3 is hollow in order to allow the air coming from the
discharge door 18 to penetrate therein in order to accelerate the cooling of the
baked products by becoming heated itself in order to then escape to the exterior
by any suitable opening. For this object the cover is in this part of the furnace
formed of iron bars between which a vacant space 41 (Figure 6) is left which
allows of the circulation of the air.
The modification shown in Figures 8 and 9 is, as regards its main points,
similar to the one hereinbefore described and therefore I will only now describe
the difference, that is to say, its general arrangement of construction, its instal-
lation as muffle furnace, and the method of guiding and supporting the movable
bed.
The roof or cover of the furnace is here supported as in the previous case by a
series of posts 37 forming columns capable of supporting in a general manner the
upper framework of the furnace and constituting also points of support for
shafts 42 carrying rollers 43 and 44 serving to guide the movable bed which is
here supported by rollers of similar diameters 45, one of which is fast and the
other loose on the shaft 46 in order to allow of differences in the speeds of
travel.
The transformation into a muffle furnace is obtained by recessing the cover 3 of
the furnace as shown in Figure 8 and in causing the hot gases arising from the
furnace 17 to circulate in a portion of this recess (the part comprised between the
furnace 17 and the chimney 22) whilst in the other part that comprised between
the breach 18 and the chimney 47, cold air is caused to circulate as before
described, drawn from the breach 18 and escaping by the chimney 47 after having
been heated by circulating above the products to be cooled. The two parts of
the recessed cover 3 having a different object, are separated by means of a suit-
able partition.
The hollow bed 16 is (as before) heated by means of coal slack or small coal
which may be introduced by means of suitable openings 21 provided with plugs.
Similar openings for the purpose of forming peep holes may be arranged to open
either onto the bed of the furnace or on to the recesses at 19 in which is placed
as usual a hygroscopic or moisture absorbing substance capable of absorbing the
moisture or vapour arising from the products to be baked.
The furnace arranged in the manner just specified allows of the drawbacks
inherent in the methods of baking hitherto employed to be suppressed and among
other things it allows-
1. The operation to be carried on continuously and very rapidly with a small
quantity of goods at a time
2. The fire to be left stationary whilst shifting or moving the products to be
baked.
3. Heating or cooling of the products to be effected methodically and in an
absolutely progressive manner.
4. Perfect uniformity of the temperature in the baking zone to be insured by
the method of construction itself.
5. The vapour arising from products imperfectly dried beforehand to be
absorbed by the use of hygroscopic substances placed in the bed, the grave incon-
venience of which vapour consists in it preventing the lower part of the bed of the
furnace from being raised to the same temperature as the other parts of the
apparatus.
6. The furnace to be arranged to work equally well with a naked fire or as a
muffle furnace, in this latter case avoiding the expense of boxes or crucibles and
the end casing of enamelled products.
7. Finally, a certain quantity of fuel to be placed in the hollow bed allowing

page_text: of the lower part of the furnace being thus brought to an even temperature and
of a reducing atmosphere being obtained in case of need in the zone comprised
between the fires and the chimney, by the admission in this part of a small
quantity of air. The latter point is of the highest importance in many cases and
mainly in the case of baking porcelain, the clay of which always contains traces
of iron.
II. THE DRYING APPARATUS, Figures 10-15:
This drying apparatus which is arranged as a whole, like the furnace herein-
before described, is annular in form and comprises a platform 1 in a single piece
(as opposed to drying apparatuses formed on carriages) forming one with the
internal wall 2 and the cover 3 Figures 10 and 11, the whole of said arrangement
being suitably supported as in the furnace previously described by a metallic
frame 4 capable of being connected as in the case shown in Figures 10 and 11
with a central shaft 5 terminated at its lower part by a pivot 6 revolving in a
foot-step 7 at the bottom of which is a steel disc and at its upper end by a
journal 9 revolving in roller bearings 10 suitably mounted in the rafters and
forming a guiding device similar to that described for the furnace; or, as shown
in Figures 14 and 15 travelling on rollers or bevel rollers 30, themselves in turn
travelling on a suitable track 31. In this latter case as the pivot forming the
axis is suppressed, the lower part of the apparatus is consolidated by means of
the framework 32 and horizontal tie rods 33 of a length capable of being
adjusted as required, the whole being mounted on collars 34 and 35 capable of
revolving on a vertical central shaft 36 solidly mounted on the ground similar to
that hereinbefore described for the furnace.
The whole of this arrangement adjusts itself (Figures 10 and 11) with a suffi-
cient play against the external wall 11 which is fixed and completes the drying
chamber by the addition of sand baths or joints 12 and 13. Of these two sand
baths, one 12 is connected with the movable bed and the partition 14 is fixed,
and the other 13 is fixed and the partition 15 is movable, as may easily be seen
from a simple inspection of the drawing but it is quite evident that the arrange-
ment might be made vice versa. In the case of the arrangement shown in
Figures 14 and 15 the sand bath 13 in which the movable partition revolves is
retained but the sand bath 12 is replaced by a special joint obtained by attaching
to the cover 3, which in this case is fixed and forms one with the external wall 11,
a band of cloth or canvas 37 which falls over the internal wall 2 and forms as
shown in Figure 14 a sufficiently tight joint to prevent the hot gases from escap-
ing from the drying chamber.
The breach or door 16 for charging and discharging the drying apparatus is
arranged in the wall 11, also the hot air inlets 17 which may be fitted with
regulating gratings or registers, or not, as preferred, and which communicate by
a passage 18 with the apparatus 19 producing the hot air, and also an opening 20
serving to bring the cooled air to the discharge chimney 21. The movement is
transmitted to the platform 1 in an inverse direction to the travel of the hot
air, either by hand or by any suitable mechanical means such for instance as a
windlass, according to the size of the load which is to be set in operation. The
moving forward of this platform is made in greater or lesser steps and at intervals
according to the nature of the products to be dried.
In order to ensure the progressive heating and drying of the products to
avoid too great a cooling of the air which would have for a result to render it too
heavy and consequently make it more difficult to extract, it is well to multiply
the hot air inlets as shown in the drawing so as to be able to reheat this air
and thus to retard its point of saturation.
In order to prevent the hot air from following the vacant space existing
between the platform and the fixed wall 11 a suitable number of vertical shut-
ters 23 as shown as an example in Figures 11, 12 and 13, may be arranged in said
space, which shutters are mounted above and below on pivots 24 and have on

page_text: both faces springs 25 which have a constant tendency to return them to a normal
position, that is to say radially whenever under the action of the expansion of the
platform they are turned in one or other direction. These shutters thus form zig
zags which constantly tend to bring the hot air back onto the upper part of the
platform.
The working of this drying apparatus explains itself. The dried articles
having been discharged by the breach 16 the movable bed 1 is loaded afresh from
this breach and the movable sole thus loaded is set in motion in an inverse direc-
tion to that of the movement of the hot gas so that the products to be dried first
encounter the gas considerably cooled and almost saturated with moisture. They
then meet air which becomes gradually hotter and which enters the drying
apparatus by openings 17, until they finally again arrive at the charging breach 16.
During this time the gases more and more saturated with moisture follow an
inverse course in order to reach the chimney 21 and escape into the open air.
A perfect and regular drying of the particles is thus obtained with an apparatus
occupying a minimum of space.
It is quite evident that the drying apparatus and furnaces hereinbefore
described whilst being more particularly intended for effecting the drying and
baking of ceramic articles are not exclusively restricted to this, but may of
course serve for drying and baking other suitable products without its being
necessary to change anything in their essential and characteristic parts.
Dated this 4th day of October 1898.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
Improvements in Furnaces and Drying Apparatuses having a
Movable Bed for Ceramic and other Products.
I, HENRI STURM, of 18, Rue Mogador, Paris, in the Republic of France,
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 has for its object certain improvements in ceramic furnaces and
drying apparatuses having a movable sole, said improvements consisting in com-
bining the sole or movable annular chamber constituting the main element of the
furnace or drying apparatus, with a wall, casing or fixed sheathing, against
which said sole or movable annular chamber revolves, being suitably supported
by means of an arrangement of pivots or rollers, sand baths or other like devices
being employed for preventing the escape of the warm air or the products of com-
bustion, and openings or ports being formed to give passage to the air or pro-
ducts of combustion according to whether it is a question of a drying apparatus
or of a furnace.
In order that the object of the present application may be more clearly under-
stood, I will now refer to the drawings accompanying the Provisional Specification,
in which:
Figure 1 is a sectional elevation of a furnace arranged in conformity with my
invention having a sole or bed mounted on a pivot, the section being taken on
the line A. Z B of Figure 3;
Figure 2 is a partial section of the said furnace made on the line C-D of
Figure 3, passing through the furnace;

page_text: Figure 3 is a sectional plan view of the said furnace made at different levels,
the parts between the radii K L, M P, R S, and T U representing a plan view
from above; the part between the radii M P and R S representing a horizontal
section made on the line N-0 of Figure 2; the part between the radii T U
and V X representing a horizontal section taken on the line I-J of Figure 1;
the part between the radii V X and Q Y a horizontal section made on the
line G-H of Figure 1 and finally the part between the radii Q Y and K L repre-
senting a section made on the line E-F of Figure 1;
Figure 4 a sectional elevation of a furnace of the same kind having a sole
mounted on bevel rollers, the said section being made on the line A-Z-B' of
Figure 5;
Figure 5 a partial sectional plan view of the same figure at different levels, the
part between the radii K¹ Z' and M Z representing a plan view from above the
furnace, the transverse girders or beams being supposed to be removed; the part
between the radii K' 7, T¹ Z representing a horizontal section of the same made
on the line G-H" of Figure 4; the part between the radii M¹ Z, S₁ Z repre-
senting a horizontal section of the same made on the line A-B" of the same
figure; the part between the radii Z¹ S₁ and Z B₁ representing a horizontal section
made on the line CD" Figure 4; the part between the radii Z B¹ and Z¹ L'
representing a horizontal section made above the plane of the support rollers;
and finally the part comprised between radii ZT and Z L¹ a horizontal section
made on the line EF Figure 5;
Figure 6 a transverse section on the line P-Z' Figure 5;
Figure 7 is a detail view on an enlarged scale of the lower vertical movable
wall of the revolving sole or bed;
Figures 8 and 9 are respectively transverse sectional and plan views at different
levels as herein before described of another modification of the furnace arranged
on the same principle but capable of operating as a muffle furnace and in which
the movable bed or sole is supported on ordinary cylindrical rollers.
The same reference letters represent the same parts in this first group of figures.
Figure 10 is a view in sectional elevation taken on the line A-B of Figure 11
of a drying apparatus having a revoluble chamber mounted on a pivot arranged
on the same principle as the furnace;
Figure 11 represents respectively a plan view from above the drying apparatus;
the part in section comprised between the radii G H and K L are horizontal
sectional views of the same drying apparatus made on the line C-D (the part
comprised between the radii G H, MN) and on the line E-F (the part com-
prised between the radii K L and M N);
.
Figures 12 and 13 are respectively an elevation and a plan view of a part of the
apparatus, the working of which will be hereinafter described;
Figure 14 is a sectional elevation on the line O-P Q-R of Figure 15 of a
modification of the drying apparatus arranged under similar conditions but
mounted on rollers;
Figure 15 is respectively a plan view from above of the drying apparatus (the
part comprised between the radii S T and U V) and horizontal sectional views of
the same drying apparatus made on the line AB (the part comprised between
the radii UV and X Y) also on the line E-F (the part comprised between the
radii S T and Z 7) and on the line C-D) (the part comprised between the

page_text: combustion follow an inverse direction to that of the wall or bed so that the pro-
ducts to be baked arrive at the baking zone after first passing through zones in
which the temperature rises gradually, the cooling being also effected in a pro-
gressively increasing manner by the absorption of a large part of the heat
accumulated in the baked or burned products by à circulation of air which
becomes progressively heated and which may then be. utilized in any suitable
manner; the atmosphere of the furnace is also capable of being rendered an oxidis-
ing or a reducing one, and hygrometric substances may if desired be placed in the
hollow sole in order to absorb the vapour produced. An oxidising or a reducing
atmosphere is simply obtained by the method of firing. An atmosphere is reduc-
ing when the furnace produces carbonic oxide. It is oxidising when the furnace
produces carbonic acid. The furnace produces carbonic oxide when little air is
admitted to the fire. It produces on the contrary carbonic acid when much air is
admitted to the fire. This does not form part of the invention.
The whole of these various parts may be combined in various ways and more
particularly the revolving bed or sole may be supported in various manners such
as will be hereafter explained.
1 indicates the bed of the furnace attached to the inner wall 2 and separated
with sufficient play from the external wall 11 which is fixed. The roof or cover 3
may either be movable as shown in Figures 1 and 2 and in this case form one with
the internal movable wall 2, or be fixed as shown in Figures 4, 6 and 8
and then form one with the external wall 11. The whole of this arrangement,
completed by the addition of sand baths or joints 12 and 13, forms the working
furnace. These sand baths are connected either with the movable bed 1 and 2,
or with the fixed outer wall 11 of the furnace, their corresponding partitions 14
and 15 being then connected either to the fixed wall or to the movable bed, as an
inspection of the drawing will easily show. The solidarity existing between the
bed 1 and the internal wall 2 of the furnace forms a very appreciable advantage
from the point of view of charging certain products which require to be better
supported than they are in the case of an ordinary furnace with movable bed.
The bed 1 of the furnace is hollow and the products of combustion when it is
a question of a furnace fired with a naked fire pass partly beneath the said bed aš
shown in Figures 2 and 4 in order that the bottom of the articles may be baked
or fired simultaneously with the upper part. In order therefore to ensure the
uniform baking or firing, the hollow part 16 of the bed may be supplied with
combustible which ignites as soon as it approaches the zone of baking and pro-
duces the desired result. The external fixed wall 11 of the furnace contains the
furnace or furnaces 17 as well as the breech 18 or door serving for effecting both
the charging and discharging of the furnace which facilitates its working.
On the other hand I arrange below the hollows of the bed, properly so called,
a hollow chamber 19 communicating with the exterior by suitable openings 20
and in which I place quicklime or any other suitable hygroscopic substances
intended to absorb the vapour which is given off when the products have been
newly placed in the furnace, which as a rule causes inconveniences, and, difficulties
in the baking. This substance is dehydrated again after each passage through the
zone of high temperature.
Small flues 21 arranged vertically or horizontally in the interior wall 2 of the
furnace and closed by means of suitable valves or plugs may as required serve
either as flues for assisting the combustion or as peep holes or charging hoppers
for introducing in case of need additional fuel if by chance that inserted by
the charging hoppers was not sufficient. This arrangement of furnace is com-
pleted by a chimney 22 having a register 24 serving for allowing the products of
combustion to escape, and an arrangement of doors 23 serving to insulate, from
the other parts of the furnace, the part where the charging and discharging of
the articles to be baked is effected.
In order to avoid deformations of the internal fire clay lining 2 and to allow
the free expansion of this interior lining, I form it by means of bricks 26 (see

page_text: more particularly the horizontal section in Figure 3 made on the line E-F of
Figure 1) which engage or fit one into another and which may be placed dry and
without too much compression at the joints in order to allow the free expansion
of this lining. When there are two linings 2 and 25 as shown in Figures 1, 2
and 3 it is preferable not to connect these two linings together in order to avoid
deformations of the masonry arising from the greater expansion of the masonry
of the lining 2 than that of the lining 25.
'
In order to allow the working of the furnace to be seen it is advisable to
arrange peep holes such as 27 (Figures 1 and 2) at suitable distances apart enabling
the progress of the baking to be followed in order to allow of its being regulated
as required.
The revolving bed such as hereinbefore described may be supported in various
ways. In the case shown in Figures 1, 2 and 3, the whole of the bed 1 and the
interior wall 2 and of the cover 3 is supported by a metallic framework 4 con-
nected with a central shaft 5 which is terminated at its lower part by a pivot 6
revolving in a foot step 7, at the bottom of which is a disc of steel 8, and at its
upper part by a journal 9 revolving in a roller bearing box 10 suitably arranged
in the rafters of the roof and forming a device for guiding.
In the case shown in Figures 4, 5, 6 and 7 the whole of the bed 1 and the
interior wall 2 travel on bevel rollers 30 which in turn travel on a suitablė
track 31. In this case the pivot constituting the axis is dispensed with, and the
lower part of the apparatus is consolidated by means of a framework 32 and hori-
zontal drawbars 33 of suitable length capable of being adjusted as required, the
whole fastened together by collars 34 and 35 capable of revolving on a central
vertical shaft 36 solidly mounted in the ground. The cover 3 of the furnace,
which is here fixed, is supported by a series of posts 37 on which are supported
tie bars 38 and 39 serving to consolidate and sustain a ring or crown 40 forming
the internal armature of the ceiling.
At part of its length in the part of the furnace where the.cooling of the burnt
or baked products is effected (the part comprised between the radii M¹ Z¹
and S¹ Z) the roof or cover 3 is hollow in order to allow the air coming from the
discharge door 18 to penetrate therein in order to accelerate the cooling of the
baked products by becoming heated itself in order to then escape to the exterior
by any suitable opening. For this object the cover is in this part of the furnace
formed of iron bars between which a vacant space 41 (Figure 6) is left which
allows of the circulation of the air.
The modification shown in Figures 8 and 9 is, as regards its main points,
similar to the one herein before described and therefore I will only now describe
the difference, that is to say, its general arrangement of construction, its instal-
lation as muffle furnace, and the method of guiding and supporting the movable
bed.
The roof or cover of the furnace is here supported as in the previous case by a
series of posts 37 forming columns capable of supporting in a general manner the
upper framework of the furnace and constituting also points of support for
shafts 42 carrying rollers 43 and 44 serving to guide the movable bed which is
here supported by rollers of similar diameters 45, one of which is fast and the
other loose on the shaft 46 in order to allow of differences in the speeds of
travel.
The transformation into a muffle furnace is obtained by recessing the cover 3 of
the furnace as shown in Figure 8 and in causing the hot gases arising from the
furnace 17 to circulate in a portion of this recess (the part comprised between the
furnace 17 and the chimney 22) whilst in the other part that comprised between
the breach 18 and the chimney 47, cold air is caused to circulate as before
described, drawn from the breach 18 and escaping by the chimney 47 after having
been heated by circulating above the products to be cooled. The two parts of
the recessed cover 3 having a different object, are separated by means of a suit-
able partition.

page_text: The hollow bed 16 is (as before) heated by means of coal slack or small coal
which may be introduced by means of suitable openings 21 provided with plugs.
Similar openings for the purpose of forming peep holes may be arranged to open
either onto the bed of the furnace or on to the recesses at 19 in which is placed
as usual a hygroscopic or moisture absorbing substance capable of absorbing the
moisture or vapour arising from the products to be baked.
The furnace arranged in the manner just specified allows of the drawbacks
inherent in the methods of baking hitherto employed to be suppressed and among
other things it allows-
1. The operation to be carried on continuously and very rapidly with a small
quantity of goods at a time.
2. The fire to be left stationary whilst shifting or moving the products to be
baked.
3. Heating or cooling of the products to be effected methodically and in an
absolutely progressive manner.
4. Perfect uniformity of the temperature in the baking zone to be insured by
the method of construction itself.
5. The vapour arising from products imperfectly dried beforehand to be
absorbed by the use of hygroscopic substances placed in the bed, the grave incon-
venience of which vapour consists in it preventing the lower part of the bed of the
furnace from being raised to the same temperature as the other parts of the
apparatus.
6. The furnace to be arranged to work equally well with a naked fire or as a
muffle furnace, in this latter case avoiding the expense of boxes or crucibles and
the end casing of enamelled products.
7. Finally, a certain quantity of fuel to be placed in the hollow bed allowing
of the lower part of the furnace being thus brought to an even temperature and
of a reducing atmosphere being obtained in case of need in the zone comprised
between the fires and the chimney, by the admission in this part of a small
quantity of air. The latter point is of the highest importance in many cases and
mainly in the case of baking porcelain, the clay of which always contains traces
of iron.
II. THE DRYING APPARATUS, Figures 10-15:
This drying apparatus which is arranged as a whole, like the furnace herein-
before described, is annular in form and comprises a platform 1 in a single piece
(as opposed to drying apparatuses formed on carriages) forming one with the
internal wall 2 and the cover 3 Figures 10 and 11, the whole of said arrangement
being suitably supported as in the furnace previously described by a metallic
frame 4 capable of being connected as in the case shown in Figures 10 and 11
with a central shaft 5 terminated at its lower part by a pivot 6 revolving in a
foot-step 7 at the bottom of which is a steel disc and at its upper end by a
journal 9 revolving in roller bearings 10 suitably mounted in the rafters and
forming a guiding device similar to that described for the furnace; or, as shown
in Figures 14 and 15 travelling on rollers or bevel rollers 30, themselves in turn
travelling on a suitable track 31. In this latter case as the pivot forming the
axis is suppressed, the lower part of the apparatus is consolidated by means of
the framework 32 and horizontal tie rods 33 of a length capable of being
adjusted as required, the whole being mounted on collars 34 and 35 capable of
revolving on a vertical central shaft 36 solidly mounted on the ground similar to
that herein before described for the furnace.
The whole of this arrangement adjusts itself (Figures 10 and 11) with a suffi-
cient play against the external wall 11 which is fixed and completes the drying
chamber by the addition of sand baths or joints 12 and 13. Of these two sand
baths, one 12 is connected with the movable bed and the partition 14 is fixed,
and the other 13 is fixed and the partition 15 is movable, as may easily be seen
from a simple inspection of the drawing but it is quite evident that the arrange-

page_text: ment might be made vice versa. In the case of the arrangement shown in
Figures 14 and 15 the sand bath 13 in which the movable partition revolves is
retained but the sand bath 12 is replaced by a special joint obtained by attaching
to the cover 3, which in this case is fixed and forms one with the external wall 11,
a band of cloth or canvas 37 which falls over the internal wall 2 and forms as
shown in Figure 14 a sufficiently tight joint to prevent the hot gases from escap-
ing from the drying chamber.
The breach or door 16 for charging and discharging the drying apparatus is
arranged in the wall 11, also the hot air inlets 17 which may be fitted with
regulating gratings or registers, or not, as preferred, and which communicate by
a passage 18 with the apparatus 19 producing the hot air, and also an opening 20
serving to bring the cooled air to the discharge chimney 21. The movement is
transmitted to the platform 1 in an inverse direction to the travel of the hot
air, either by hand or by any suitable mechanical ineans such for instance as a
windlass, according to the size of the load which is to be set in operation. The
moving forward of this platform is made in greater or lesser steps and at intervals
according to the nature of the products to be dried.
In order to ensure the progressive heating and drying of the products to
avoid too great a cooling of the air which would have for a result to render it too
heavy and consequently make it more difficult to extract, it is well to multiply
the hot air inlets as shown in the drawing so as to be able to reheat this air
and thus to retard its point of saturation.
In order to prevent the hot air from following the vacant space existing
between the platform and the fixed wall 11. a suitable number of vertical shut-
ters 23 as shown as an example in Figures 11, 12 and 13, may be arranged in said
'space, which shutters are mounted above and below on pivots 24 and have on
both faces springs 25 which have a constant tendency to return them to a normal
position, that is to say radially whenever under the action of the expansion of the
platform they are turned in one or other direction. These shutters thus form zig
zags which constantly tend to bring the hot air back onto the upper part of the
platform.
The working of this drying apparatus explains itself. The dried articles
having been discharged by the breach 16 the movable bed 1 is loaded afresh from
this breach and the movable sole thus loaded is set in motion in an inverse direc-
tion to that of the movement of the hot gas so that the products to be dried first
encounter the gas considerably cooled and almost saturated with moisture. They
then meet air which becomes gradually hotter and which enters the drying
apparatus by opening 17, until they finally again arrive at the charging breach 16.
During this time the gases more and more saturated with moisture follow an
inverse course in order to reach the chimney 21 and escape into the open air.
A perfect and regular drying of the particles is thus obtained with an apparatus
occupying a minimum of space.
It is quite evident that the drying apparatus and furnaces hereinbefore
described whilst being more particularly intended for effecting the drying and
baking of ceramic articles are not exclusively restricted to this, but may of
course serve for drying and baking other suitable products without its being
necessary to change anything in their essential and characteristic parts.
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:-
The improvements in furnaces and drying apparatuses having a movable bed
or chamber for ceramic and other products, consisting in the combination with
the revolving sole or bed or movable annular chamber, on which is placed the
articles to be baked or dried, of a fixed wall, sheath, or casing against which the
bed revolves and of an arrangement of sand baths or similar movable partitions
forming joints serving to prevent the escape of the products of combustion or

page_text: a
hot air, the baking or drying (as the case may be) being effected by means of an
arrangement of fixed furnace, the products of combustion of which, in the case of
baking oven or furnace, flow to the chimney in an opposite direction to that of
the rotation of the movable bed and of the products to be baked, and the atmos-
phere being capable of being rendered oxidizing or reducing, hygroscopic sub-
stances being placed in the hollow bed in order to absorb the vapour produced,
whilst in the drying apparatus the hot air is conveyed from the apparatus pro-
ducing it by means of openings connected by one or more flues, vertical spring
shutters forming in this case zag zags serving to constantly return the hot air onto
the useful part of the platform; the whole substantially as described and shown:
Dated this 14th day of June 1899.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.