Improvements in and connected with Muffles.
Year: 1894

page_text: Date of Application, 21st Feb., 1894
Complete Specification Left, 2nd Apr., 1894-Accepted, 25th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in and connected with Muffles.
I, FRANZ GUILLEAUME of Bonn in the Kingdom of Prussia, German Empire,
Manufacturer, do hereby declare the nature of said invention to be as follows
--
This invention relates to muffles such for instance as those used in the production
of ceramic ware for burning the colour into earthenware or porcelain, the object
being to so heat the said muffles that an even temperature is maintained throughout
the interior thereof. This is obtained by a peculiar position of the grate, in
combination with a particular arrangement of the passages for the heating gases as
will be hereinafter described.
The fire grate of the furnace is situated below the front end of the muffle floor
which is thus heated directly by the fire. The remaining part of the muffle floor is
heated by the products of combustion which are caused to pass over an inclined wall
rising from the fire grate to the rear. Between the said inclined wall and the muffle
floor the gases branch off into a number of flues arranged on the side walls of the
muffle which may, however, be united to form a single flue having an oblong
sectional area. By these flues the gases are conducted upwards into a space
arranged above the roof of the muffle. From this space the gases are conducted
downwards again by another set of flues or passages, which likewise may be united
to form a single shallow passage, at the front end of the muffle walls, the said
downtake passages being slightly bent round the fire space and terminating in a
passage below the furnace which leads into the chimney.
These two groups of flues for conducting the gases upwards and downwards are
separated on either side by solid walls which are continued into the roof space to
form two bridges by which the gases rising out of the uptake flues are prevented
from entering directly into the downtake flues. These bridges reduce the roof
space and produce a mixing of the gases.
The horizontal area of the uptake flues or passages is greater than that of the
downtake flues so that the current of gases in the latter will have a greater velocity
than in the first-named flues. In order to obtain an even distribution of the gases
in the uptake flues or passages the inlets of the latter are made with different area so
that the inlet is the greater the greater the distance between the respective flue
and the fire grate, and if a single large flue be employed instead of the separate
flues, its inlet may have the forin of a triangle whose apex is turned towards the
grate. The gases which flow through the downtake flues having parted with a part of
their heat are cooler than those rising in the uptake flues but this difficulty in the
production of an equal temperature in the muffle is neutralized by the greater velocity
at which the gases flow through these flues and by the heat received by this part of
the muffle direct from the fire grate beneath. Under the inclined wall herein before
mentioned a chamber is provided for the beating of air prior to its being used to
support combustion, this chamber being also heated from below by the gases
discharged from the downtake flues into the passage leading them to the chimney.
A valve or damper is provided in the outlet of said passage to enable the regulation of
the draught.
Dated the 21st day of February 1894.

page_text: improvements in and connected with Muffles.
I, FRANZ GUILLEAUME of Bonn in the Kingdom of Prussia, German Empire,
Manufacturer, do hereby declare the nature of said 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 muffles such for instance as those used in the production
of ceramic ware for burning the colour into earthenware or porcelain, the object
being to so heat the said muffles that an even temperature is maintained
throughout the interior thereof. This is obtained by a peculiar position of the
grate, in combination with a particular arrangement of the passages for the heating
gases as will be presently described, reference being had to the accompanying
drawings in which
Fig 1 is a vertical longitudinal section through a muffle constructed according to
this invention,
Fig. 2 a horizontal section on the line 2-2 Fig. 1.
Fig. 3 a vertical transverse section on the line 3-3 Fig. 1.
Fig. 4 a vertical transverse section on the line 4-4 Fig. 1 and
Fig. 5 a vertical transverse section on the line 5-5 Fig. 1.
Figs. 1 and 2 are respectively a vertical longitudinal section and a transverse
section (on the line 2-2 Fig. 1A) of a modified construction, Fig. 34 is a vertical
section on the line 38-3ª Fig. 14.
The fire grate a of the furnace is situated below the front end of the muffle floor b
which is thus heated directly by the fire. The remaining part of the muffle floor
is heated by the products of combustion which are caused to pass over an inclined
wall e rising from the fire grate a to the rear. Between the said inclined wall and
the muffle floor the gases branch off into a number of flues d arranged on the side
walls of the muffle which may, however, be united to form a single flue having an
oblong sectional area as shown in Figs. 14 and 2^ where this passage is indicated by
the letter d*. By these flues d the gases are conducted upwards into a space e
arranged above the roof of the muffle. From this space e the gases are conducted
downwards again by another set of flues or passages f, at the front end of the
muffle walls, the said downtake passages f being slightly bent round the fire space
and terminating in a passage g below the furnace which leads into the chimney.
These passages likewise may be united to form a single passage as represented
in Figs. 1 and 2 where this passage is indicated by the letter f*.
These two groups of flues d and f for conducting the gases upwards and downwards
are separated on either side by solid walls h which are continued into the roof
space e to form two bridges i by which the gases rising out of the up-take flues d
are prevented from entering directly into the downtake flues f. These bridges i
reduce the roof space e and produce a mixing of the gases.
The horizontal area of the uptake flues or passages d is greater than that of the
downtake flues so that the current of gases in the latter will have a greater
velocity than in the first named flues. In order to obtain an even distribution of
the gases in the uptake flues or passages d the inlets d' of the latter are made with
different areas (see Fig. 1) so that the inlet is the greater the greater the distance
between the respective flue d and the fire grate a, and if a single large flue d* be
employed instead of the separate flues d, its inlet d' may have the form of a triangle
whose apex is turned towards the grate as shown in Fig. 14. The gases which flow
through the downtake flues having parted with a part of their heat, are cooler
than those rising in the uptake flues d but this difficulty in the production of an
equal temperature in the muffle is neutralized by the greater velocity at which the

page_text: gases flow through these flues and by the heat received by this part of the muffle
direct from the fire grate a beneath.
Under the inclined wall c a chamber k may be provided for the heating of air
prior to its being used to support combustion, this chamber being also heated from
below by the gases discharged from the downtake flues finto the passage g leading
them to the chimney.
A valve or damper / provided in the outlet of the eduction passage g serves the
purpose of regulating the draught.
Having now particularly described and ascertained. the nature of said inven
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In muffles the combination, with the fire grate (a), of uptake passages (d)
arranged behind the fire grate on each side of the muffle and having inlet-openings
of increasing width, downtake passages (f) arranged on each side of the muffle at
the fire-grate end of the same, and a space (e) arranged above the roof of the
muffle into which space lead the uptake passages, and from which part the
downtake passages, the said uptake and downtake passages having different
sectional areas and being separated from each other by solid walls (h)
continued into the said space so as to form bridges (i), so that the heating
gases are caused to uniformly heat the sides, the roof and the floor of the
muffle first by the increasing width of the inlet openings (d') of the uptake passages,
secondly by being prevented by said bridges from directly entering the downtake
passages, and thirdly by having imparted increased velocity in the downtake
passages, the heating of the front part of the said floor being assisted by the heat
radiating from the fire, substantially as described.
2. The modified arrangement which consists in uniting each series of passages
(d & frespectively into one passage d* & f* respectively) substantially as described
and shown in Figs. 1 and 2^.
3. In muffles such as claimed the arrangement, between the inlet openings or
opening of the uptake passages or passage and the passage leading from the outlet
openings or opening of the downtake passages or passage to the chimney, of a
chamber (k) for the purpose of heating air for combustion, substantially as
described.
Dated the Second day of April 1894.
JOHNSONS & WILLCOX,
Agents.