Improvements in and relating to Pottery Ware and like Glaze Firing Furnaces and Kilns.
Year: 1896

page_text: Date of Application, 12th Mar., 1896-Accepted, 25th Apr., 1896
COMPLETE SPECIFICATION.
Improvements in and relating to Pottery Ware and like Glaze
Firing Furnaces and Kilns.
I, CARL MAYER, Engineer, of Annawerk, Oeslau, Germany, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
This invention relates to the construction of benches of muffle furnaces and
arrangement of flues therein, also to a system of firing and burning porcelain and
other enamelled or glazed ware, by nesting a series of muffle furnaces in a bench or
benches (single or double), and in employing therewith a travelling furnace capable
of connection and imparting the necessary intensity of heat to each muffle in the
series in succession for perfecting the firing or burning operation, the escaping heat
from such muffle under direct action being guided by suitable flues and dampers
into the next muffle to be so acted upon for pre-heating such muffle, fresh air
simultaneously entering other channels for passage through the previously heated
muffle furnace or furnaces for cooling same. The air which has become rarefied
by the heat thereof being employed to assist combustion of fuel in the traveller
furnace which can be moved along and temporarily located with any muffle furnace
of the series or bench.
According to the present or known system of burning high-grade glazed and
porcelain ware it is done in ordinary kilns which have to be fired for each
charge separately. The reasons why this old fashioned system is still in use
are:-
1. The sensitiveness of the articles to changes in temperature.
2. The delicate nature of the articles themselves rendering them liable to
damage.
3. The articles being easily spoiled through dust and dirt burning into them.
This system is very wasteful in fuel, and only yields a limited production.
Therefore a system has been generally in use for low-grade goods in which the
articles to be burnt are placed in movable receptacles which are passed through
a flue over a fire i.e. entering a flue at one end and leaving it at the other, being
subjected during the passage through the flue to various temperatures.
As the costly process of starting a fire and letting it burn out for each charge,
the production is greater for the same quantity of fuel than in the first method
described for high-grade goods, but this system has several disadvantages,
such as:-
1. Loss through cracking because of insufficient regularity in the various
temperatures.
2. Articles being spoiled through dirt burning into them.
3. Great expense owing to the receptacles containing the articles burning
away.
4. Entailing difficult and beavy labour.
Moreover this process is still wasteful in fuel.
In my system all these drawbacks and faults are done away with, and the fuel is
tilised to considerably better advantage.

page_text: I describe my new system with reference to the annexed drawings as
follows:-
In the drawings
Figure 1 part sectional elevation through the line y, y, of Figure 2 which is
a transverse section through line x, x, of Figure 1.
Figure 3 indicates how the furnace carried on rails can be closed up to the
mouth of the muffle.
Figure 1 represents a kiln showing four separate chainbers in which the articles
to be burnt are placed arranged one by the side of the other, but such number
is immaterial, and they could also be arranged one above the other, or back
to back.
Each chamber has a channel b to allow the exit of pre-heated air, and a
channel c to allow the entrance of the heating gases.
Both b and c can be closed with covers.
The channel d between b and c can also be closed.
The passages e and f between the separate chambers can be closed by slides g
and h.
Each chamber moreover has a passage k communicating with the chimney flue /
which can be shut off by the slide i and a passage with the channel n which can be
shut off by the slide m.
The furnace o is movable and is easily placed and clamped in position in front of
each chamber. This furnace has passages p and q corresponding with the
passages b and c. The furnace is also made capable of being shifted laterally to
be in contact against c and b.
Joints are made between c and q, and between 6 and p with loam or other
suitable substance when the furnace is pressed against the kiln.
I have shown the lateral shifting of the furnace at Figure 3 as being effected
by means of a screws and hand wheel t but it can be done by levers, after being
run on the rails to the mouth of the kiln to be heated by it.
I explain the working of my kilns as follows:-
In Figure 1 the burning of the articles in the chambers 1 and 2 is supposed to
have been performed and the furnace o is operating on chamber 3, and chamber 4
is being pre-heated. The process is as follows:-
Cool air enters through channel b of the chamber 1 playing in the direction of
the arrows on chambers 1 and 2 and cools them and takes up heat in passing.
This air now pre-heated enters through channel b of the chamber 3, through
channel p into the fire of the furnace o.
The flame, products of combustion, and the hot gases from the furnace then
enter through channel c of the chamber 3, playing on chamber 3, then passing to
the chamber 4, pre-heating the latter, after which they pass through channel k of
the chamber into the escape flue l.
Channel n, when the furnace is operating chamber 4, serves for leading the fire
gases to chamber 1, the fresh warmed air being led through channels r, k, to
chamber 1.
If a great number of chambers is wanted it is better to arrange them in several
parallel rows instead of one long row so as not to have the channels n aude too
long, or the chambers can be arranged polygon or circularwise.
The furnace can equally well be fired by a generator, in that case the air
channels can be arranged as shown in the dotted line between c and b.
Another important advantage gained by my system is that after burning of a
charge has been completed, the fire is instantly removed and the after-heat which
is so detrimental to some colours is prevented.
In practice, the furnace o being at No. 3 kiln the products of combustion pass
up and heat finish the muffle therein. The hot gases escaping therefrom pass
through passage to kiln No. 4 to pre-heat its muffle, the damper h being opened
for the purpose. The hot gases then descend down the passager into channel k

page_text: open.
to flue and away to the chimney, the damper i of that part of the flue being
Simultaneously cool air enters No. 1 kiln by passages b, e, to cool its muffle, the
intermediate lid d¹ being opened and the damper 9 closed, so that the air passes
upwards around muffle in kiln No. 1, the upper back damper m of which is closed,
and the transverse damper h open for the air to pass therefrom and downwardly
into No. 2 kiln around the muffle therein whereby those two muffles become
cooled down and the air finally travels to the lower channel e of No. 2 kilu, thence
into passages 6 and p to feed the furnace o, there being always one muffle pre-
heating, one muffle finish heating by fire heat, and two muffles' being cooled
down by incoming air which in a hot condition goes to feed the furnace.
When the furnace is locked against kiln No. 4, the gaseous products pass
along the back channel n and descend down in kiln No. 1 and pre-heats
No. 1 muffle, and thence into the flue 1, air for cooling muffles Nos. 2 and 3
flowing through them, and so on.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In kilns for firing or fixing glaze on porcelain and similar ware, the use of a
movable furnace to serve any one of the firing chambers, as set forth.
2. The construction of a bench of muffle furnaces with the necessary passages
for the utilization of incoming air for cooling the articles that have been burnt,
which at the same time becomes warmed for admixture with the combustible hot
gases of the heating furnace together with the utilization of such hot gases
going from the heated furnace for warming the articles in the remaining chambers
preparatory to the firing of the articles in the next adjoining chamber or chambers,
as described.
Dated this 12th day of March 1896
H. GARDNER,
Patent Agent, 166 Fleet Street, London,
Agent for the said Carl Mayer.