Improvements in the Manufacture of Fire-clay and Magnesian Bricks and in Kilns for Firing same.
Year: 1891

page_text: Date of Application, 2nd Apr.. 1891
Complete Specification Left, 2nd Feb., 1892-Accepted, 2nd Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Fire-clay and Magnesian
Bricks and in Kilns for Firing same.
I, OSCAR CLAUSEN of Simferopol in the Empire of Russia, but at present
residing at 37 Fitzroy Square, London, W., Engineer, do hereby declare the
nature of this invention to be as follows:-
My invention relates to the manufacture of fire-clay bricks and also to their
subsequent manipulation for conversion into magnesian bricks, while it also relates
to the construction of the kilns employed in the manufacture of same.
The bricks produced according to my invention are particularly adapted for use
in the stove or furnace which I have described in an application for a Patent made
by me on the 23rd of December 1890 under No. 20955.
The bricks are made of the usual fire-clay mixed in certain proportions with good
plastic potters clay and sawdust or the like, the mixture being slightly moistened
with water, well kneaded and left to stand for a few days, and then kneaded a
second time, after which it is ready to be moulded into bricks, which bricks are in
a fit state to be put directly into a kiln to be fired.
If it is desired to convert the bricks so produced into a magnesian brick it is
plunged into magnesian water containing a small quantity of calcined magnesia, and
finally dried in the air.
The kiln I prefer to employ is preferably round with a covered top, the fireplace
being in the middle and shut off from the firing chamber. The fireplace is fed from
a shaft having an outside opening in which the fuel is introduced, said fireplace
being filled with the quantity of fuel necessary for firing the batch of bricks and
afterwards closed hermetically from the outside. Air is supplied to support
combustion at the bottom of the fireplace. A series of these kilns are employed,
the products being passed over and through the bricks in the first kiln, from thence
into the second, and so on with the object of utilizing the waste heat and preventing
the emission of smoke.
The bricks made according to my invention are very porous and light and will
stand a high temperature when in use.
Dated this 2nd day of April 1801
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Fire-clay and Magnesian
Bricks and in Kilns for Firing same.
I OSCAR CLAUSEN of Simferopol in the Empire of Russia, 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 relates to the manufacture of fire-clay bricks, shaped articles and
the like, and to their subsequent manipulation for conversion into magnesian bricks
while it also relates to the construction of the kilns employed in the firing of same
and other articles.
The bricks produced according to this invention are particularly adapted for use
in the stove or furnace described in the Specification to Clausen's Patent No. 20955
of 1890, as well as in other places. The bricks may be prepared from various sorts
of pure plastic fireclay by mixing it with sawdust, ground peat, or like material in

page_text: about equal proportions by volume. If the fireclay is pure white kaolin or china
clay and is not sufficiently plastic it would be necessary first to add 25% by volume
of good plastic potters clay. In most cases it will be found that all sorts of clay
require a previous washing to separate sand and other impurities contained therein.
The mixture of fireclay and sawdust is slightly inoistened with water and kneaded
with the feet or suitable machinery into a thick uniform paste, after which it is left
for some days, kneaded a second time and made into bricks in moulds by hand or
dry presses, and the moulded ware is then placed in a kiln preferably constructed
as hereinafter described, where, in a space of two or three days it is dried by the
action of the warm gases from the combustion of a previous baking, which gases
are caused to pass through the section in which the raw ware is placed, before they
reach the chimney, and the ware is then finally baked and cooled.
If it is desired to convert the baked bricks made by this process into magnesian
bricks, it is sufficient to dip them for a few moments into water in which magnesia
is suspended as described in the Specification before referred to, this magnesial
water containing about 1 lb. of magnesia in 100 gallons of water, after which they
are dried in the air. In place of magnesia mixed with water, a bath or solution
containing a dissolved magnesium compound may be used, such for example as
carbonate of magnesia dissolved in water containing carbonic acid. A solution of
sulphate or chloride of magnesium may similarly be used, and in such cases one
pound or more of the magnesium compound may be used to 100 gallons of water.
The firebricks so prepared are exceedingly porous and light, and bear the
continuous action of very high temperature-3700° to 5500° F., with little
deterioration, and do not crack or burst or even change their form under various
and frequent changes of temperature.
In consequence of their extreme porosity they possess a very insignificant and
almost unobservable coefficient of expansion under variations of temperature, and
on this account it is possible to give to the bricks various complicated and delicate
shapes, and further it enables them to be used in places subject to frequent changes
of temperature, such as in stoves and furnaces.
These bricks on account of their porosity are bad condensors of heat, but
excellent preservers and absorbers of saine. For this reason they are well adapted
for the construction of stoves, particularly when they are converted, as above
described, into porous magnesian firebricks.
The kiln which is preferably employed in firing the bricks manufactured as above
described is illustrated in the accompanying drawings, in which
Fig. 1 is a sectional elevation of a three chambered kiln, the section being taken
on the line a-a of Fig. 2.
Fig. 2 in its upper half is a plan taken on the line y-y, Fig. 1; its lower portion
being a plan on the line - of same figure, and
Fig. 3 is a diagrammatic view being a section taken through the centres of the
three kilns and spread out on the flat.
As represented, three firing chambers are employed and this is deemed a suitable
number for small works, but for large works from five to twelve or more of such
chambers may be used. Each chamber may be considered as a separate kiln with
all necessary appliances, such as furnace, coal supply apparatus, and separate flues
opening at the end into one common chimney, but all are connected between them-
selves by flues, and all three work in each separate baking. The kiln may be
constructed of unbaked bricks prepared as hereinbefore described, it works without
giving any appreciable smoke and enables the utilisation of the whole heat furnished
by the fuel and part of the heat of the bricks baked in them, and with it bricks
can be baked at a temperature higher than 6000° F. by reason of the improved
combustion obtained therein by the supply of heated air from the bricks baked in
the other sections. In working the kiln the fuel is put into each separate division
through a conical sloping shaft A. (which is then closed) in sufficient quantity for
the whole baking of the ware which is placed in one of the divisions of the kiln,
these divisions being preferably dome shaped chambers C, as shown.

page_text: The fuel during the process of baking slowly and uniformly sinks in the conical
shaft by its own weight and enters into the furnace B as the combustion proceeds.
therein.
The furnace B is cylindrical and is provided with perforated walls which com-
municate with an annular space D which communicates with a lower flue E
connecting the three fireplaces, while the chamber C is provided with a false bottom.
on which the ware is placed, beneath this being a space communicating by means
of passages F with an upper flue G which connects the three chambers C with each
other. Both of these flues E and G are provided with suitable dampers or
shutters H and I, the action of which is hereinafter explained.
The process of baking is carried on as follows :-
The raw articles are first put into all three chambers of the kiln and the
shutter H on the lower connecting flue E between the furnaces of chambers Nos. 1
and 2 is closed, and the shutters I of the upper flue G between the same chambers
and also between the chambers Nos. 2 and 3 and the shutter K leading to the
chimney L are all opened.
Then through the door of the ashpit of the first furnace B the fuel is set alight,
the products of combustion from this furnace rise from same and enter into the
firing chamber No. 1 which is filled with the raw ware which for two or three days
may be allowed to absorb from the hot gases their first and greatest heat until it is
completely baked. The gases of the combustion during this period after giving off
their first heat pass considerably cooled but still warm through the flues G, first
into chamber No. 2 and then into No. 3 in which they give off their last heat to the
raw ware therein drying them in the process, and after this they escape through
the chimney L. When the baking is finished in the first division the door of its
ashpit is hermetically closed, and the shutter H of the lower flue E connecting the
furnace of chambers Nos. 1 and 2 is opened, after which the firing chamber No. 1
is broken open by removing the brickwork which has been employed to close its
charging orifice, and the shutter of the upper flue G between chambers Nos. 1
and 2 is closed. The fuel in the furnace B of chamber No. 2 is now set alight and
the door of the furnace is closed, consequently the fuel must draw air for its
combustion through flue E from the furnace of chamber No. 1, the air being drawn
through the baked ware which it slowly cools, and through the heated contents of
the furnace, so that it enters the furnace of chamber No. 2 considerably warmed,
and this raises the temperature of the products of combustion. These products now
communicate their heat to the ware placed in chamber No. 2 and will bake same in
about two days. The gases after baking the ware pass through flue G through one
of the shutters I which is open and into chamber No. 3 where they dry the ware
therein and leave same through the chimney L. The baking of the ware being
finished in chamber No. 2 the ware baked in chamber No. 1, now sufficiently cooled,
is taken out and it is filled as quickly as possible with fresh raw ware, the opening
therein which has been previously broken open being again bricked up. The
shutter H of the lower flue E between chambers Nos. 1 and 2 is then closed as well
as the shutter I of the upper flue G between chambers Nos. 2 and 3, and also the
shutter K of the chimney L. The shutter H of the lower flue between chambers
Nos. 2 and 3, and the shutter I of the upper flue between chambers Nos. 3 and 1,
and the shutter K of the vertical flue of chamber No. 1 leading to chimney L
are opened. The bricked up hole through which the ware was placed in
chamber No. 2 is then broken open and the fuel is set alight in the furnace of
chamber No. 3 through the door of the ashpit which is then closed and the whole
process is repeated, the products of combustion baking the ware in chamber No. 3
causing it to be cooled in chamber No. 2 by reason of the draught therethrough,
and drying the fresh ware in chamber No. 1, and subsequently passing through the
vertical flue of chamber No. 1 to the chimney L. When the baking in
chamber No. 3 is finished the fire is again started in the furnace of chamber No. 1,
and the same circular process of drying, baking and cooling begins again.

page_text: Having now particularly described and ascertained the nature of the inven-
tion of the said Oscar Clausen and in what manner the same is to be performed I
declare that what I claim is :-
1. The employment in the manufacture of fireclay bricks and the like of saw-
dust, ground peat, or similar material with or without an admixture of plastic
potters clay, substantially as described.
2. In the manufacture of magnesian bricks or the like immersing a brick
composed of, or containing fireclay and sawdust or peat or the like in a magnesial
solution or magnesia suspended in water substantially as described.
3. The kiln for burning bricks and other articles having the furnaces, chambers,
flues, and shutters adapted to carry on the series of operations of drying, baking,
and cooling, constructed substantially as described and illustrated.
Dated this 2nd day of February 1899
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Chartered Patent Agent.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Chartered Patent Agent.