Improvements connected with the Production of Purple Ore Bricks or Blocks for use in Blast Furnaces or other Furnaces, for the Production of Iron and for other purposes.
Year: 1893

page_text: Date of Application, 24th Feb., 1893-Accepted, 6th May, 1893
COMPLETE SPECIFICATION.
Improvements connected with the Production of Purple Ore Bricks
or Blocks for use in Blast Furnaces or other Furnaces, for the
Production of Iron and for other purposes.
I, HENRY BIRD, of South Down House, near Plymouth, in the County of Devon,
Chemist, 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 has mainly for its object, the production of bricks or blocks of
"purple-ore" resulting from the common process of the extraction of the copper
contained in burnt cupreous sulphur ores by the wet method, or from other washed
cupreous sulphur ores, or equivalent ores, with the object of rendering this material
suitable for use, mainly, in the blast furnace, or other furnaces, for the production
of iron, and also for other purposes, as bricks or blocks.
I have found that in the burning of purple ore bricks or blocks in kilns, that no
species of kilns used for making building and like bricks, or burning earthenware
material of any kind, are wholly successful for the purpose. In my practice in
this manufacture of "purple-ore" blocks or bricks, I have mostly used that known
as the "Downdraught Staffordshire kiln," and this is one of the few, so far as I
am aware, in which purple ore blocks or bricks can even with moderate success be
burnt, having regard to economy of fuel; but even in this, difficulties and want of
ease of working, arise, and too constant attention is required; and it is the object
of this invention to provide a construction and mode of working kilns which shall
be capable of being used without the drawbacks and difficulties, and want of ease
referred to, or in other words, by which purple ore bricks or blocks can be uniformly
burnt aud produced of a uniform degree of hardness, and no damage will happen to
the furnaces or kilns, or to the bricks, and also that the process may be carried on
continuously without abnormal care and attention.
To this end, I arrange and construct kilns for this purpose, and operate them, or
proceed, as hereinafter set forth, with reference to the accompanying drawings,
which the difficulties and objections above referred to are obviated or overcome.
In these drawings,
Figure 1 is a plan of the kilns, and Figure 1* is a section through the condenser
in Figure 1 taken at the line E. F.
Figure 2 is a longitudinal cross section through the kilns Nos. 1, 2, and 3 of
Figure 1 at A. B.
Figure 3 is a longitudinal section taken through the kilns at the links C D
Figure 1.
Figure 34 is a section at the line G. H. Figure 1.
Figure 4 is a sectional plan taken at the line E. F. Figure 2.
Figure 4 is a section across bridge flue.
Figure 5 is a general outside end view of the kilns arranged as in Figure 1.
Figure 6 is a cross section through one of the kilns with the blocks or bricks
packed in the arrangement best suited to their burning.
Figure 7 is a front elevation, Figure 8 is a longitudinal section, and Figure 9
is a sectional plan of the arrangement of furnace flash walls and the fire gas
discharge conduits; whilst Figure 10 is a view of same viewed from the inside of
the kiln.
Figure 11 shews, in different views, a suitable form of bearer for supporting fire-
bars, but which forms no part of the invention.
*Figure 12 is a plan in section of plant arranged under this invention.

page_text: According to this invention, there is used a plurality of kilns connected together,
and communicating with each other by flues and conduits in such a manner as to
be worked according to a "continuous" method, the conduits being so arranged,
and provided with means of closing and opening same, that the heat of the fire
gases coming from a chamber being fired, and that of the bricks and kilns after
being fired, are, as far as possible, utilized in the preliminary stages of drying,
and heating other bricks to be burnt. Further, under this invention, the
furnaces and gas conduits are so arranged as to uniformly heat and burn the
blocks or bricks, and produce blocks or bricks of uniform hardness. Further,
the kilns are so constructed that the bricks or blocks stacked or piled therein
do not have a tendency to fall outwards from the pile or stack. Also the kilns
are so constructed that they are able to resist pressure which tend to thrust
them asunder and to disintegrate them; and also to resist the pressure of bricks
or blocks should they fall or press outwards. Further, the kilns are so arranged
and built that they can be filled and in a very easy manner, from the block
making house and readily emptied..
Referring now to the drawings, the kilns are of what are known as the
"Staffordshire Downdraught" type, that is to say, the heating gases when
burning the blocks or bricks, leave the kilns by apertures in the floor thereof.
In the arrangement shewn there are five kilns or chambers 1, 2, 3, 4, 5, and
they are so connected with flues or conduits that they can be worked in such a
manner as to economize heat in the process of kilning, which comprises the
drying of the fresh damp blocks or bricks, firing, and cooling.
Each kiln consists of brickwork walls some of which have flues within them,
as hereafter described, and they each have a series of fire-places, which are
designated 10, arranged on each side, and wickets 11 and 12, which, when bricks
are being dried, burned, or cooled, that is to say under treatment, are closed up
by a daubed stopping wall in the usual way, which is removed when emptying and
filling. In addition to this wall in wicket 11, the wicket is recessed with a rebate
at 11, in which an iron or other filling sheet is placed, so that a hollow space
exists within the wicket; and when air and steam are being conducted from the
central flue under the kiln, into the escape air and steam flue, which is at the top
end of the kiln above 11, as hereinafter described, the space serves as a conduit
to connect said two flues.
It will be seen the kilns are arranged in a series of five, but any other suitable
number may be employed.
The kilns, as will be seen, are rectangular in plan, with an arched roof and with
internal side walls having an inward batter, this inward batter is provided in
order to resist the tendency of the walls of kilns to be thrust outwards. The
floors 13 of the kilns are arranged or constructed at an inclination, falling from
the side walls towards the centre. This construction is provided in order that the
pile or stack of blocks or bricks, on each side of the centre, shall have a tendency
to fall towards one another and not outwards, so that the two halves support each
other. I have found that if the purple ore blocks or bricks are stacked in the
ordinary way, i.e. upright, they frequently fall towards the side, and coming in
contact with the side walls and flash walls they become fluxed, and the process
thus becomes troublesome. Further, to protect the stack against this tendency to
fall, I provide at different parts of the stack continuous tie bricks or blocks 14,
running from end to end of the kiln, as shewn in Figure 6. These give stability
to the stack or pile.
The kilns are arranged in rows, as shewn, and two or more are built in one structure.
These structures have tunnels T through them, in which the firing is done, and
through which the wet bricks from the making house (which is designated Z in
Figures 1 and 3) are carried to the kilns in the row furthest from the house;
whilst the wet bricks are taken from the making house Z direct into the first row
of kilns through the wickets 11 therein, and into the second row of kilns through
the wickets 11 of that row, through the firing tunnels T between the kilns of the

page_text: first row.
In discharging, the burnt bricks are taken out through the opposite
wickets 12 of the first row of kilns in a direct line, those from the outer two
(in Figure 12) passing on the outside of the second row of kilns, and those from
the centre one passing through the firing tunnel of the second row.
By building the kilns together in multiple in rows in this manner, the usual
staying by buckstaves, etcetera, is not required, and the different chambers are
stronger and better held together, and enabled to withstand warping tendencies.
As regards the construction of the fire-places, flash walls and fire-gas distributing
conduits (see Figures 7 to 10), I provide a solid flash wall 15 along the whole
interior surface of the sides of the kilns to the levels shewn, and in these flash walls,
at the end of the fire-places 10, are provided vertical flues 16; and from these flues
lead distributing horizontal flues 17, in which distributing apertures or nostrils 18
are provided, the apertures at the inner side of which are downwardly inclined. The
vertical flues are also provided with a distributing aperture or nostril 19 in it, similar
to the others. By constructing these apertures or nostrils with an inclined sill and
pen lent lintel, falling pieces of purple ore bricks or blocks are shot off, that is they
cannot lodge, and thus are prevented from fluxing the flash wall.
By distributing the gases in this way, I find that the heating and burning of the
blocks or bricks is rendered more uniform in the different parts of the kiln, and that
the bricks are in consequence of a more uniform hardness, and partially or semi-
burnt bricks in different portions of the kiln do not occur.
At the top of each fire-place 10 an aperture 20 is provided between the crown 21
and the fire-place arch, forming an air space, and a direct sight through said air
space and one of the fire gas apertures 19 can be taken at any time by removing a
removable brick at 22 and the condition of the stack of bricks ascertained: thus a
ready means of telling, in what state the burning process is, is afforded. Also the
fire-places are rendered more durable by said air space, and if the crowns 21
become burnt they can readily be replaced.
There is also provided in the flash wall opposite the entrance of the flue kilns,
which. convey the waste fire-gases from one kiln, into a kiln containing dried bricks,
a distributing aperture 23 and an upward flue or passage 24.
I will now describe the mode of conducting the process of kilning:
It may be assumed a kiln No. 1 contains dry hot blocks which have been dried by
air heated by passing it over finished and hot blocks or bricks in No. 3, which are
being cooled by such air; and that they now are being brought to a red heat
or approximately a red heat, by the "waste" fire gases from No. 5. (These gases
are introduced into kiln No. 1 by the underground flue a¹ from kiln No. 5, they
being admitted from a¹ to No. 1 by the conduit b', and past the valve b¹×
controlling 6', and which for the time being is withdrawn). These gases from this
kiln No. 1, pass away from the kiln by the apertures c¹ in the bottom 13 thereof,
which lead direct into the underground flue d¹, and are carried by the flues (past
the damper valve f¹ which is open) into the common escape flue q, which leads the
gases to the condenser chamber R, hereinafter referred to. Fires are then lighted
in the fire-places of No. 1 (that is, when the blocks in No. 5 have been fully burned
and firing ceases in that chamber), and the blocks burned to the required degree ;
and the damper f' closed. The hot "waste "fire gases from No. 1 pass by way of
the apertures c in the bottom of the kiln, into the flue d', and are led from thence
into kiln No. 2 by the underground flues e¹ and a' (which is a continuation of e¹),
and the vertical flue b' (the valve 6x of which is withdrawn), in the same manner
as they were led into No. 1 from No. 5 as above described.
After the blocks in No. 1 have been sufficiently fired and allowed to soak for
sufficient time, air is admitted into the central underground flue d' by removing a
covering slab or plate ¹× in the wicket 11.
This air rises up through the red hot blocks and becomes highly heated; and
then passes by the conduit h¹ at the top end of the kiln, past the valve damper h¹*,
which is withdrawn, into the hot air flue by which it is conducted to the upper
part of chamber 4 by way of a bridge conduit ; and the hot air conduit 4* thereof.

page_text: air descends through them into the bottom flue d* thereof, and then passes by the
passage (and damper *** which is withdrawn from same) through the wicket
way 11 at the end of the kiln, between the daubed stopping wall 25 and sheet of
iron 26, and an outlet equivalent to in Figure 3 above same (which is controlled
by a damper-see 1¹× Figure 3-now withdrawn), into the waste air and steam
flue m, and thence to the chimney by the bridge conduit n. At this stage, the
conditions of the different chambers will be as follows:-
1. Red hot blocks being fired for finishing.
2. Dried blocks being heated by waste fire.
3. Freshly made blocks being dried by hot air from No. 5.
4. In process of being emptied and filled.
5. Blocks cooling resulting hot air being taken to No. 3.
The same parts as regards flues and valves of the different kilns are marked with
the same letters of reference as those used with reference to kiln No. 1, but for
distinguishing same, and for the purposes of explanation, the said letters in the
different kilns are provided with the index corresponding with the No. of the kiln,
to which they are applied; and it may be here stated that each of the kilns is
provided with the same means of conveying gases to and from same.
The waste gases after their heat has been abstracted from them, and they have
been discharged into the flue y, are led into the condenser R, (which is of a form
used for condensing arsenic) wherein the lead sulphate and other fumes given off
from the purple ore is condensed; and the gases, thus ridded of obnoxious fumes,
are discharged into the chimney S through the connecting conduit p.
Kiln 5 when discharging its cooled waste gases into the condenser R, does so
through the upright part of flue & (controlled by the valve or damper which is
withdrawn in such case, but which otherwise covers the aperture e³) which connects
said flue with the condenser. This flue e passes under the condenser.
It will be seen that the waste gas flue 9 is connected to all 5 kilns, and that the
gases flow into it from either side.
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 the production of purple ore blocks or bricks, the employment of kilns
arranged in series and provided with flues or conduits for conducting gases,
air, etcetera, from one to the other and away from same, said kilns and flues or
conduits being arranged and adapted to be operated substantially as herein set
forth, and as shewn in the drawings hereto annexed.
2. In kilns for the production of purple ore blocks or bricks, the arrangement in
connection with a series of kiln chambers, of the underground flues with dampers or
valves therein, and the flues in the upper level in the brick-work of said kilns, as
and for the purposes set forth with reference to the drawings.
3. A kiln for burning purple ore blocks or bricks in which the fire gases are
conveyed away through the floor or lower part of same through flues therein, and
fire-places arranged along each side, and the inner surface or sides whereof are
provided with conduits and apertures for the fire gases by which said fire-gases are
distributed; substantially as set forth with reference to Figures 7, 8, 9, 10 of the
drawings.
4. A kiln for burning purple ore blocks or bricks having fire-places along each
side and solid flash walls, arranged and constructed as set forth with reference to the
drawings for the purposes set forth.
5. A kiln for burning purple ore bricks or blocks having its bottom inclined and
adapted to support the blocks or bricks to be burnt; substantially as set forth.
6. The kilns arranged as set forth and shewn in the drawings in rows or batches
of two or more chambers each, forming separate structures and with firing tunnels
through same, and filling and discharging wickets, the filling and discharging

page_text: wickets of the one row being opposite or in line with the firing tunnel of the other ;
as and for the purposes herein set forth.
7. A kiln for burning purple ore bricks or blocks of the form shewn in the
drawings, and having flues, inlet and outlet apertures or conduits, valves, and
filling and discharging wickets, all arranged and adapted to operate particularly as
set forth and shewn in the drawings.
1000
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicant's Patent Agents.