Improvements in or relating to Muffle Furnaces or Ovens.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Muffle Furnaces or Ovens.
I, LOUIS HUBERT WILLEM REGOUT, of Stationstraat 32, Maestricht, in the
Kingdom of Holland, Engineer, do hereby declare the nature of this invention
to be as follows:
The present invention relates to a muffle furnace or
working with direct base firing.
oven for continuous
In the ordinary annular muffle furnaces a direct base firing is not generally
possible, owing to the arrangements of the wheels required for the movement
of the rotating annular plate underneath the muffle, and because this annular
plate forms at the same time the bottom of the muffle.
The present invention refers to muffle furnaces or ovens in which direct base
firing is made possible, while continuous working by means of an annular plate
or support is not interfered with.
For this purpose the bottom of the muffle is solid and in every part constructed
of fire resisting material, with a few small openings at intervals from which,
project cast iron rollers for the rotating bottom plate or support. These rollers,
however, are not placed directly over the fire space. The furnace consists. of
an annular passage, the dimensions of which depend on the quantity of material
to be treated.
A part of the furnace, i.e. the muffle, in which the burning process is carried
out is directly heated, and this part is constructed entirely of fire-resisting stone
or material.
The parts which serve respectively for the preliminary heating and for the
cooling of the articles after burning are preferably constructed partly of fire
resisting material and partly of metal. The fire from the grate comes in direct
The heating gases ascend by way of
contact with the bottom of the muffle.
lateral passages and surround the muffle before they are allowed to escape through
the chimney.
The muffle furnace is provided with a continuous rotary bottom arranged a
little above the bottom of the muffle. This travelling surface is supported on
iron rollers and consists of a grating of cross bars or plates on which the articles
to be treated are placed.
By rotating the travelling support the articles pass first through the space
where the preliminary heating is effected, then through the muffle, and after-
wards through the cooling space from which they pass on and return to the
5 original position and can be removed from the furnace.
The annular furnace consists of a section which is exposed directly to the
strong fire and consequently is constructed exclusively of fire resisting material,
two sections adjoining the firing section which are exposed to a less intense heat
also constructed of fire-resisting material and two sections before the

page_text: preliminary heating sections, made of sheet iron or plates and finally a section
which is left open.
One section serves for the introduction and renewal of the charge, or the
articles to be treated, the next two sections serve for the preliminary heating,
the next section for the burning, and the next two for the cooling of the articles
treated.
The firing space or grate is beneath the muffle.
The flames produced on the grate bars come in contact directly with the
bottom of the muffle, the heating gases then ascend through passages on both
sides of the chamber into the space above the muffle and envelope completely
the surface of the muffle up to the chimney, passing through passages which are
arranged around the muffle, and finally escaping by the chimney.
In the annular furnace there is an annular bottom plate or support comprising
steel rails or bars which are connected at intervals by ties or rods and covered
with bars or plates.
The steel rails are supported on rollers which are mounted on axles which are
capable of rotation in stationary bearings and are so arranged that the axles and
bearings are not exposed to the heat of the fire.
The rotatory annular bottom support extending through the whole furnace is
thus produced. On this travelling support are placed the articles to be treated,
bars or guards being arranged at the sides to protect the articles from falling
over. The travelling support, together with the articles standing on it, is then
moved onward by means of toothed wheel gearing. The bottom of the muffle is
solid and constructed of fire clay plates, and there are only in a few places, at
intervals, small passages or recesses through which the rollers project into the
heating and cooling spaces. The operation is as follows:-
After the articles to be treated have been placed on the supporting surface they
are introduced in consequence of the rotary movement imparted to it, first into
the preliminary heating part of the furnace, which is not directly heated.
On further rotation the articles are introduced into the section in which the
firing process is carried out, and they remain there until the operation is finished,
during which time the articles already in the next forward part have time to
cool and the articles in the front section are completely cooled, after which the
completely cooled articles are removed. In the corresponding parts cooling can
be accelerated by suitable means.
This arrangement therefore unites the advantages of a continuous working
with that of a direct base firing.
The heating is produced gradually and cooling is carried out in the same way
until the articles have reached the place where they are removed, in consequence
of which arrangement the cracking of even large objects need not be apprehended.
This manner of utilising the firing material is very advantageous and produces
an economy of between 70 and 80% as compared with the old muffle systems.
The new muffle furnace is especially adapted for burning in colours, and gold
on china, earthenware, stoneware, glass and enamel iron patterns.
Dated this 23rd day of June 1899.
BOULT & WADE,
Agents for the Applicant.

page_text: and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
The present invention relates to a muffle furnace or oven for continuous
working with direct base firing.
In the ordinary annular muffle furnaces a direct base firing is properly not
possible, owing to the arrangements of the wheels required for the movement of
the rotating annular plate underneath the muffle, and because this annular
plate forms at the same time the bottom of the muffle.
The present invention refers to muffle furnaces or ovens in which direct base
firing is made possible, while continuous working by means of an annular plate
or support is not interfered with.
For this purpose the bottom of the muffle is solid and in every part constructed
of fire resisting material, with a few small openings at intervals, from which
project cast iron rollers for the rotating bottom plate or support. These rollers,
however, are not placed directly over the grate. The furnace consists of an
annular passage, the dimensions of which depend on the material to be treated.
A part of the furnace i.e. the muffle, in which the burning process is carried
out is directly heated, and this part is constructed entirely of fire-resisting stone
or material.
The parts which serve respectively for the preliminary heating and for the
cooling of the articles after burning are preferably constructed partly of fire
resisting material and partly of metal. The fire from the grate comes in direct
contact with the bottom of the muffle. The heating gases ascend by way of
lateral passages and surround the muffle before they are allowed to escape through
the chimney.
The muffle furnace is provided with a continuous rotary bottom arranged a
little above the bottom of the muffle. This travelling surface is supported on
iron rollers and consists of a grating of cross bars or plates on which the articles
to be treated are placed.
By rotating the continuous rotary bottom the articles will pass first through
the space where the preliminary heating is effected, then through the muffle,
and afterwards through the cooling space from which they pass on and return
to the original position and can be removed from the furnace. The new muffle
furnace is represented in the accompanying drawing,
Figure 1 being a plan view, partly in section, of the muffle furnace, and
Figure 2 a vertical section through the furnace at the firing place but on a
larger scale than Figure 1.
The annular furnace o consists of a section B-C which is exposed directly to
the fierce fire and which is consequently constructed exclusively of fire resisting
material, two sections A-B and C-D) adjoining the firing section, which are
exposed to a less intense heat and are also constructed of fire-resisting material,
the section D-E before the preliminary heating section D-C and which is made
of sheet iron or plates as well as the section A-F for the cooling and finally of
a section F-E which is left open.
The section E-F serves for the introduction and removal of the charge of
the articles to be treated, the next two sections E-D and D-C serve for the
preliminary heating, the next section B-C for the burning and the next two
B-A and A-F for the cooling of the articles treated.
The firing space or grate a is located beneath the muffle g (Figure 2).
The flames produced on the grate bars 6 come in contact directly with the
bottom of the muffle, the heating gases then ascend through passages d on
both sides of the chamber into the space e above the muffle and envelop com-
pletely the surface of the muffle, up to the chimney f, passing through the
passages (Figure 1) which are arranged around the muffle and finally escaping
by the chimney.
t
The passagest form a double flue, which runs spirally round the muffle up
to the chimney f. The heating gases from the space e above the muffle enter

page_text: first the two flues t on the left hand side, pass underneath the bottom plate to
the two flues on the right hand side (innerside Figure 1), then above the
muffle to the second pair of flues t on the left hand side (outside) of the muffle
and so on underneath and above spirally around the muffle until the chimney f
is reached.
In the annular furnace there is an annular bottom plate or support comprising
steel rails or bars h which are connected at intervals by ties or rods and covered
with bars or plates n.
The steel rails are supported on rollers & which are mounted on axles / and
which are capable of rotation in stationary bearings m and are so arranged that
the axles and bearings are not exposed to the heat of the fire. Thus a rotary
annular bottom support extending through the whole, furnace is produced.
On this travelling support are placed the articles to be treated, bars or guards p
(Figure 2) being arranged at the sides to protect the articles from falling over.
The travelling support, together with the articles standing on it, is then moved
onward preferably by means of a crank and a toothed wheel gearing 9 Figure 1,
which is connected to a drum and chain, the other end of the chain being hooked
to the travelling support.
The bottom c of the muffle g is solid and constructed of fire-clay plates, and
there are only, in a few places, at intervals, small passages or recesses through
which the rollers k project into the heating and cooling spaces C-D, C-B
and B-A. As shown in Figure 1 these recesses are not located in the muffle
bottom plate c above the grate a.
The operation is as follows: -
After the articles to be treated have been placed in the part E-F on the sur-
face of the travelling support they are introduced, in consequence of the rotary
movement imparted to it, first into the part E-1) of the furnace and then into
the part D-C which is not directly heated, where they are preliminarily heated.
On further rotation the articles are introduced into the section C-B in which
the firing process is carried out, and they remain there until the operation is
finished, during which time the articles already in the next forward part B-A,
which were previously in C-B, have time to cool and the articles in the front
section A-F are completely cooled; after which the completely cooled articles
are removed from the support in the part F-E. In the parts B-A and A-F
cooling can be accelerated by suitable means.
As will be seen this arrangement unites the advantages of a continuous work-
ing with that of a direct base firing.
The heating is produced gradually and cooling is carried out in the same way
until the articles have reached the place where they are removed, in consequence
of which arrangement the cracking of even large objects need not be apprehended.
Warping of the annular support in consequence of the partial heating is pre-
vented by connecting the rails h firmly by stays i.
Expansion by heat of the support is provided for as the axles of the rollers &
have sufficient play in their bearings to move sideways with the support.
This manner of utilizing the firing material is very advantageous and pro-
duces a great economy as compared with the old muffle systems.
The new muffle furnace is especially adapted for burning in colours and gold
on china, earthenware, stoneware, glass and enamelled iron plates.
Having now particularly described and ascertained the nature of my said.
invention and in what manner the same is to be performed, I declare that what
I claim is:
-
1. An annular muffled furnace comprising an annular rotatory support with
means for rotating the same a heating chamber at one portion of the annular
muffle furnace arranged below the support, a muffle above the heating chamber,
a preliminary heating section of the furnace and a cooling section substantially
as set forth

page_text: 2. In an annular muffle furnace an annular rotatory support comprising a
pair of rails connected at intervals by cross ties a series of wheels upon which
Said rails are supported and a floor laid upon said rails on which the articles to
be baked are placed and means for rotating the annular support substantially
as set forth.
3. In an annular muffle furnace of the kind described an arrangement whereby
the stationary supporting wheels and axles are not located above the heating
chamber but outside said chamber and out of contact with the heating gases the
bearings to said axles being arranged on the outside wall of the muffle furnace
substantially as described.
4. An annular muffle furnace with continuous working and direct base firing
characterised by the arrangement of an annular rotatory support, on which the
articles to be treated are placed, said support comprising a pair of annular rails
united by cross ties and provided with a suitable floor, the rails being supported
on rollers arranged at intervals on both sides of the furnace and in such manner
that the heating gases produced underneath the muffle and passing round the
muffle do not touch the support and the rollers, and means for rotating the tra-
velling support so that the articles to be heated pass successively through the pre-
liminary heating space, then through the muffle and then through the cooling
space of the furnace, substantially as described.
5. In an annular muffle furnace a heating chamber a a muffle c, a rotatory
annular bottom support, rails h, supporting wheels k combustion gas passages d
and t, substantially as described.
6. In a muffle furnace of the kind described a series of rollers for supporting
and rotating the movable support mounted in fixed bearings in such manner
that they cannot be reached by the heating gases substantially as described.
7. A muffle furnace, provided with a travelling support for the articles to be
treated, comprising a muffle as c, a surrounding casing, passages dt for the
heating gases, and a grate underneath the muffle substantially as described.
of March 1900.
BOULT, WADE & KILBURN,
Agents for the Applicant.