Improvements in Kilns for Firing Firebricks, Earthenware, and the like.
Year: 1890

page_text: Date of Application, 3rd Nov., 1890-Accepted, 14th Mar., 1891
COMPLETE SPECIFICATION.
Improvements in Kilns for Firing Firebricks, Earthenware, and
the like.
I, JAMES DUNNACHIE, of Glenboig, in the County of Lanark, North Britain,
Fireclay Manufacturer, 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, that is to say :-
My said invention relates to kilns of the kind described in my Patent Specification,
No. 3862 of 1881, and one of my present objects is to improve the operation of
such kilns by supplementing the supply of heat at a particular stage of the actions,
so as to rapidly drive off moisture from the bricks or other articles, prior to the
application of the strongest heat. My present invention also includes a modified
arrangement suitable where a comparatively small number of chambers or kilns are
combined.
In the arrangement of kilns to which some of my present improvements are to
be applied, a number of chambers or kilns are combined in such manner that the
successive stages of heating, firing, and cooling are passed through by each in
rotation. The firing is effected by the combustion of producer gas, or other suitable
gas, in one chamber, and the hot gases after acting in that chamber pass through
ports or flues into the next chamber, and thence through one or more other
chambers, so as to utilise their gradually diminishing heat in heating to different
degrees the articles in the several chambers. On the firing having continued long
enough in one chamber, the combustible gas is shut off from that chamber, and
admitted to the next one in order. Air is admitted into the chamber containing
the already fired articles, and whilst cooling them is itself thereby heated; and
this heated air being led through flues or ports into the next chamber supplies
what is required for the combustion of the gas at the same time utilising the heat
it has taken up. The flues or passages communicating between the several chambers
and those through which the gas is supplied are made with numerous small ports
so that the gases are equally distributed over the chambers and uniform action is
thereby secured.
By my present invention I provide for introducing into each chamber, during
whatever stage of the operations may be thought best, a number of comparatively
small jets of gas for rapidly driving off moisture from the bricks or other articles
in the chamber, these jets issuing through orifices suitably distributed in the floor
of the chamber and communicating with one or more special supply flues beneath.
And in order that my said invention and the manner of performing the same
may be properly understood I hereunto append two Sheets of explanatory drawings
to be hereinafter referred to and showing the application of my improvements.
Figures, 1, and 2, on Sheet, 1, of the drawings are respectively a vertical section
and a horizontal section showing a portion of the series of chambers or kilns,
A1, A2, A3, A4, composing a set or system of kilns for firing firebricks, carthen-
ware, and the like. If we suppose a charge of bricks to have been just fired in
chamber, A 1, air admitted into that chamber and taking up heat will pass through
ports, B1, down into a flue, C1, thence through ports into a flue, D 1, and up
through ports the passage through which is controlled by damper slabs into an
upper flue, E 1.
From the flue, E 1, the heated air issues by numerous small ports
into the chamber, A 2, and mixes at once with combustible gas issuing upwards
through ports, F 2, from a flue, G 2, receiving the gas through ports from a supply

page_text: flue, H2. There are similar ports and flues in connection with each chamber, as
indicated by like reference letters distinguished by different numerals; and there
are also communications between the chambers at the upper parts of the division
walls, as and for the purposes described in my earlier Specification hereinbefore
referred to.
According to my present invention there are formed under the floor of each
chainber or kiln, two small gas supply flues, J, which are indicated by dotted
lines in Figure, 2, and which communicate with the chamber by a number of small
jet orifices, K, which I term "steaming "holes as the ignited jets from them cause
the moisture from the bricks or other articles in the chamber to be driven off in
steam. The lower part of the right-hand end of Figure, 1, is delineated, in section
as at the line, L-L, in Figure, 2, and shows the connection of the small supple-
mentary flues, J, by a cross flue, M, with the larger gas supply flue, H. A damper
slab, N, is provided for closing the opening between the flues, M, and H, and is
got at through an opening above to cover which a slab, P, is provided. When gas
is to be admitted to the supplementary flues, J, of any chamber, it is shut off by a
damper or valve, Q, from the part of the flue, F; communicating with the flue, G,
of that chamber.
Figures, 3, and 4, on Sheet, 2, of the drawings are respectivelya vertical section.
and a horizontal section of my modified arrangement to be adopted when the size
of the works allows of only a comparatively small number of chambers or kilns,
say two or more being combined instead of the ten or twelve usually arranged in
two rows in my complete rotation system.
::
In the modified arrangement shown in Figures, 3, and 4, the second, third, and if,
any, other chambers or kilns, A 2, A3, etc., are the same as those shown in Figures, 1,
and 2, and hereinbefore described, including by preference but not essentially, the
supplementary gas flues, J, and "steaming holes, K; but the first chamber, A, is
arranged to be heated, exclusively or mainly, by means of ordinary hopper
furnaces, R, constructed at the outer side of the chamber, A, that is, at the end of
the series of chambers. These furnaces, R, which are of a well known construction,
have each an inclined supply inlet or hopper, S, for fuel, inclined grate bars, T,
and an arched roof, through a port, U, in which air is admitted from a flue, V,
extending across the series of furnaces. The heated fire gases pass from the
furnaces, R, into the chamber, A..
The fire gases which operate in the first chamber, A, pass on from that chamber
to the second, A 2, and third, A. 3. and it may be others, so long as there is
available heat in the gases, and the actions in those chambers, A.2, A. 3, etc., are
the same as in those of the complete rotation system as described with reference to
Figures, 1, and 2. When the articles in the first chamber, A, have been,
sufficiently fired air is admitted into the chamber to cool the fired articles and be
thereby itself heated to enhance the combustion of the gas in the next chamber.
The chamber, A, may have gas-supply flues and other parts originally constructed
in connection with it, to be used in the event of the series of chambers being
extended to form a complete rotation system; but to be closed when not used.
i
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. In kilns for firing firebricks, earthenware, and the like, and constructed as
described in a connected series with gas supply flues, communicating flues, and
distributing ports, for the operation of successive stages in the several kilns or
chambers in rotation, the additional gas flues and jet orifices to supplement the
heat at any stage, the same being arranged and operating substantially as herein-
before described.
2. In a combination of kilns comprising two or more chambers, constructing
hopper furnaces in connection with, and for heating the first chamber, but

page_text: otherwise arranging the chambers with communicating and gas supply flues and
distributing ports, substantially as and for the purposes hereinbefore described with
reference to Figures 3, and 4, of the accompanying drawings.
Dated this First day of November 1890.
EDMUND HUNT,
Applicant's Agent.