Improvements in Metallurgical and other like Furnaces and Kilns for Calcining, Reducing, Carbonising, and other purposes.
Year: 1898

page_text: Date of Application, 14th Mar., 1898 ..
13
4000
++
4000
Improvements in Metallurgical and other like Furnaces and Kilns
for Calcining, Reducing, Carbonising, and other purposes.
I, JOHN ARMITAGE DRAKE, of the Firm of Jonas Drake and Son, of Slay Lane,
Ovenden, Halifax, in the County of York, Engineers, do hereby declare the nature
of this invention to be as follows:
A
This invention relates to a new and novel arrangement of recuperator whereby
the whole of the waste heat and gases from high temperature kilns, ovens, stoves
and the like may be utilised in the heating of, primary and secondary air supplies
for furnaces and required for the production of combustible gases. My improve-
ments consist in the means for effecting the more complete combustion of such gases
in combustion chambers connected therewith, the invention consisting primarily
of a number of rows of fireclay open ended tubes, placed in a horizontal or vertical
position whereby the waste furnace gases may be passed in their way to the exit
Hlue of the chimney, such course or journey of the waste gases being preferably
from front to back and back to front of the kiln in a zigzag manner until they
reach the outlet. The open ended fireclay tubes are spaced apart underneath and
sideways so that the, exit gases may be brought into close proximity to the in-
coming atmospheric air in a manner. hereinafter more fully described. The tubes
may be solid drawn or pressed in suitable forms and sections to suit various opera-
tions for which the ovens or kilns are required and also made to convenient lengths
to suit the length of traverse required to extract all the remaining heat in the
effluent gases and in order that such tubes may be made airtight to prevent the
possibility of bye-passing or short circuiting as is usual in the ordinary recupera-
tors and the bye-passing according to the present construction takes place shortly
after furnaces have been in use, arising from the shrinking of the material forming
such recuperators as well as from the shrinking of the foundation work. Now to
avoid this I arrange that each butt ended joint of the tubes shall be covered with
a fireclay belt or wall so that it absolutely prevents the effluent gases from perco-
lating.into the flues and also the air which is intended for primary and secondary
combustion from finding its way into the effluent gases and thus interfering with
the proper combustion of the fuel in the combustion chambers. The walls sup-
porting the tubes being made solid from side to side of the recuperative chamber
the incoming secondary air travellingins said "chamber will thus pass upwards
from the bottom of the recuperative tubes in a transverse zigzag
manner between the tubes and between the tubes and side walls of
the recuperative chamber alternately whereby the incoming air will absorb.
and take up the heat of the waste effluent gases on its way to the combustion
chamber. With a view to equalising the quantity of air through each space
formed by the supporting and covering walls of the tubes it is arranged that the
bricks covering, the joints of the tubes shall be recessed the said recesses being of
any suitable and convenient shape! and size but in using these recessed bricks the
flat side must cover the joint in order to make it tight whilst the recessed part will

page_text: enable the travelling air to pass from the chamber joined by the said walls of the
adjoining chamber and so on through as many chambers or divisions of chambers
as may be found necessary.
It is well understood that in ordinary recuperative furnaces the air passes through
the flues backwards and forwards from front to back and back to front.alternately
and when so constructed it is found that each time the air comes to the front
of the recuperative chamber that said air is chilled by coming in contact with and
impinging against the front wall of the chamber which radiates the heat to the
outside or exterior of the chamber, whereby a waste of heat takes place. According
to my arrangement this waste of heat in the manner described is avoided by
bringing the course of the effluent gases to the extreme back and front of the
chamber thus completely enveloping the secondary air and confining it within
the space formed by the tubes and cover walls as before mentioned and described.
It is also found desirable to cut up the incoming atmospheric air with is in-
tended for complete combustion into small portions so as to be more readily acted
upon and for this purpose I propose to place between each or all of the vertical tubes
a series of thin bricks or perforated tiles whereby the volume of air is cut up and
deflected in passing up in such a manner as to obtain the required effect.
In case a longer traverse is required for the incoming atmospheric air than is
given by the method above described, I propose to arrange a series of vertical tubes
to conduct the air over all the surface of the effluent gases tubes such vertical
tubes to be arranged in one or more tiers to conduct the air from the bottom of
the first tube to the top of the second tube whence it descends to the bottom of the
same and after passing around the tube the said air is conducted again up another
series of vertical air tubes to the third effluent gases tube and so on until as much
length of traverse is obtained as is required. When the atmospheric or secondary
air has passed over the required number of tubes it is conducted into a collecting
chamber of suitable form, this chamber being preferably covered by an arch of
firebricks or other fire resisting substance, and the said arch is carried upon and
supported by the brickwalls covering the joints of the tubes before described, but
instead of covering the chamber up with an arch, slabs of fireclay may be used
instead. A novel point of this invention is, that after providing passages from
chamber to chamber other than those previously mentioned, the said spaces are
covered up by shaped brick crowns in form fitting the radius or "camber" of the
covering arch whereby the chamber may be covered over without the use of centres
or laths as is common in forming arches. It is claimed by this arrangement that
said covering arch may and will support the weight of the said ovens or kilns in
such a manner that should any part of the tubes or walls of the recuperative
furnace become defective by reason of wear or accident it will be easy to take out
and replace any or all of the said defective parts without having in any way to
interfere with or pull out any portion of the oven or kiln proper as has hitherto
been necessary.
From the collecting chamber before mentioned the highly heated atmospheric
air is conducted through suitable exits flues or nostrils into the combustion chamber
where it meets with the furnace gases from the producer and complete combustion
takes place. In order to further assist the developement of high temperatures in
ovens and kilns before mentioned I propose to reduce the temperature of the effluent
gases as much as possible and to utilise the heat contained in the last passages
from the recuperator to the chimney and this is effected by the insertion of a coil
or row of pipes of suitable size, capacity and length into which water is allowed
to trickle from the outside or face of the kiln or oven. such water in its passage
through the said coil or row of heated pipes, being converted into steam and is
brought by another connecting pipe to the face of the kiln or oven and connected
to another series of three or more pipes by which it is conducted under the grate
bars or hearth of the producer or to suit certain classes of fuel it may be inserted
part way up in the producer. or it may be made to work part each way to suit
requirements.

page_text: In order to suit the convenience, situation or requirements of furnaces for the
purposes aforesaid, I carry out the principle of recuperation in another manner.
If a shallow-depth recuperator is required I shall preferably use in the recuperator
a special form of perforated block placed in a vertical position which block is of a
suitable height so that a series of them may be used in the space available, such
blocks having plain ends and sides with the exception that a fillet or
" rabbit"
is formed around the top and bottom of each end of the said block or by forming a
projecting lip on the outside of the top only, so that when the said blocks are placed
on the top of each other, a recess or projection as the case may be, is formed there-.
by, consequently bricks of suitable size and thickness may be inserted to conduct
the flow of the furnace gases in, a course similar to the tube arrangement first
herein mentioned, the incoming atmospheric air passing through the vertical pas-
sages in the blocks forming the division of the flues as before described and thus
pass from the lower part of the recuperator to the upper collecting chamber in the
manner before described the principle of traversing the effluent gases and covering
the secondary air passages from external radiation and utilisation of waste heat in
steam raising for re-heating purposes and covering recuperator arches is carried out
in exactly the same way in both cases.
TASKER & CROSSLEY,
Patent Agents, Halifax,
Improvements in Metallurgical and other like Furnaces and Kilns
for Calcining, Reducing, Carbonising, and other purpo:es.
I, JOHN ARMITAGE DRAKE, of the Firm of Jonas Drake and Son, of Halifax, in
the County of York, Engineers, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to a new and novel arrangement of recuperator whereby
the whole of the waste heat and gases from high temperature kilns, ovens, stoves
and the like may be utilised in the heating of primary and secondary air supplies
for furnaces, such air supplies being required for the production and utilisation of
combustible gases. My improvements consist in the means for effecting the more
complete combustion of such gases in combustion chambers connected therewith,.
the invention consisting primarily of a number of rows of fireclay open ended tubes
placed in a horizontal or vertical position through which the waste furnace gases
may be traversed on their way to the exit flue of the chimney, such course or journey
of the waste gases being preferably from front to back and back to front of the
kiln in a zig zag manner until they reach the outlet.
In order that my invention may be better understood, I have annexed the accom-
panying drawings wherein :-
Fig. 1 is a cross section on the line A A in Fig. 4.
Fig. 2 is also a cross section on the line B B in Figs. 3 and 5.
Fig. 3 is a longitudinal section on the line C C in Fig. 2.
Fig. 4 is a sectional plan on the line D D in Fig. 1.
Fig. 5 is also a sectional plan on the line E E Fig. 2.
Fig. 8 is a cross section on the line F F Fig. 13.
Fig. 9 is a cross section on the line GG Fig. 14.

page_text: Fig. 14 is also a sectional plan on the line J J Fig. 9.
Fig. 15 is a longitudinal section on the line K K in Fig. 8.
Figs. 6, 7, 10, 11 and 12 are all cross sections through different arrangements of
recuperators taken in a similar position to Figs. 1 and 2 viz:-cutting through
the effluent gas flues and the secondary air passages.
The open ended fireclay tubes are represented by letter g and are spaced apart
underneath and sideways so that the exit gases may be brought into close proximity
to the incoming atmospheric air travelling around flues a in a manner hereinafter
more fully described. The said tubes g may be solid drawn or pressed of suitable
shapes to suit the various operations for which the ovens, muffles or kilns to which
they are applied are required, and of convenient lengths to suit the length of
traverse required to extract all the remaining heat from the effluent gases. In
order that each tube may be made sound and tight and to overcome the possibility
of bye-passing or short-circuiting, as is usual, after the ordinary recuperators.
have been in operation for some time through shrinking of material forming such
recuperators or sinking of foundation work, it is arranged that each joint of tubes
will be covered with a firebrick wall & completely covering such joint so that it is
not possible for effluent gases to percolate into the air flues, or for the air intended
for primary & secondary combustion to find its way into the effluent gases flue g
& thus interfere with the proper combustion of the fuel gas in the combustion chamber.
The walls b supporting the tubes 9 & covering the joints of the same are made
solid from side to side of the recuperative chamber, except in cases specified here-
after, the incoming secondary air travelling in said chamber will pass upwards
from the bottom of recuperator tubes in a transverse zig-zag manner between the
tubes g and between the tubes & side walls of the recuperative chamber alternately
and thereby the incoming air will on its way to the combustion chamber, absorb
and take up the heat of the waste effluent gases. With a view to equalizing the
quantity of air passing through each stage formed by the supporting & joint
covering walls of tubes, it is arranged that the bricks covering the joints of tubes
shall be recessed or perforated where required in the manner shewn at c so that the
flat side may cover the joint in order to make it tight, whilst the recessed part
of the one & the holes of the other will enable the travelling air to pass from one
chamber, formed by the said walls, to the adjoining chamber, and so on for as
many chambers as may be found necessary, either with regard to the length or
to the number of tiers.
It is well known that in ordinary recuperators, the air flues, are travelled back-
wards and forwards from front to back and back to front alternately, and it is
found that each time the air comes to the front or back of recuperator it is chilled
by contact with the front or back walls (d) which radiate the heat to the outside
or exterior of chamber. By means of my invention this is avoided by bringing
the course of the effluent gases to the extreme back & front of chamber, thus com-
pletely enveloping the secondary air & confining it in the spaces formed by tubes
and supporting walls as before mentioned & described.
In view of the fact that a volume of air contains a cold core, however much it
is heated in bulk, it is found desirable to break or cut up the incoming atmospheric
air, which is intended to complete combustion, into small portions, and for this
purpose it is proposed to place between each, any one, or all the tubes, g or on the
sides thereof, a series of perforated tiles e or thin bricks e whereby the air may
be cut up, deflected, or passed in such a manner as to have the required effect
& these perforated tiles, or thin bricks, may be used jointly or severally.
In case a longer traverse is required for the incoming air than is given by the
method described, I have arranged a series of vertical channeled tiles f, see Fig. 2
to conduct the air over all the surface of the effluent gases tubes such vertical
tiles being arranged in one or more tiers to take the air from the first tube to
top of the second whence it descends to the bottom of the same & after passing
round the tube is conducted again by another series of vertical air tiles to the top

page_text: of the third effluent gases tube and so on, until as much traversing is obtained as
is required.
The same effect may be obtained by introducing plain tiles or quarries T on edge,
see Fig. 6, in place of channel tiles, on the top of which may be placed -the per-
forated bricks e for the purpose of cutting up the air as before mentioned.
When the atmospheric or secondary air has passed over the required number of
tubes it is admitted into a collecting chamber h of suitable form, this chamber h
being covered preferably by an arch 7 of firebricks or other fire-resisting substance.
This arch is carried upon and supported by the brick walls b covering the joints
of tubes before described the novel point of this invention being, that after pro-
viding passages j, from chamber to chamber other than those before mentioned,
the said passages (j) are covered by shaped brick crowns of a suitable form to the
radius or
"camber" of the covering arch whereby the said covering arch 7 may be
turned over the recuperative chamber without the aid of centres and laths, as
commonly used. By this arrangement the said covering arch 7 may, and will
support the weight of the ovens or kilns over it, in such a manner that should any
part of the tubes or walls of the recuperator become defective by reason of wear
or accident, it is easy to take out and replace any or all such deficient parts in such
recuperator without having in any way to interfere with, pull out, or renew any
portion of the oven or kiln proper above it, as has hitherto been found necessary.
To suit special circumstances the recuperator cover may be formed of tiles or
quarries laid in the form of an inverted V or laid flat as in Fig. 11.
From the collecting chamber h before mentioned, the highly heated atmospheric
air is conducted through suitable air flues or nostrils m, into the combustion cham-
ber where it meets with the combustible gases from producer and complete com-
bustion takes place.
In order to further assist in the developement of high temperatures in such
ovens or kilns before mentioned, and in order to reduce the temperature of the
effluent gases as much as possible, I utilize the heat contained in the last effluent
gas flue g in recuperator see Fig. 17 by the insertion of a coil or row of 2 or more
pipes n of suitable size, capacity and length into which water is allowed to trickle
from the outside or face of oven or kiln by means of a U pipe, q see Figs. 16, 17
and 18 with funnel top u. The water in its passage through the coil or row of
heated pipes n is converted into steam, and passing to the front of recuperator is
there connected by means of an adjustable pipe 0, with another series of three or
more pipes by which it is conducted under the gratebars or hearth of the producer
or to suit certain classes of fuel may be inserted part way up the side of producer p¹,
or may be made to work part each way to suit requirements by the arrangement of
valves shewn in (Figs. 16, 17 and 18).
In order to suit the convenience, situation, or requirements of furnaces for pur-
poses before mentioned, I carry out the principle of recuperation in another form.
If a shallow-depth recuperator is required I preferably use in the recuperator a
special perforated block (r) Figs. 8, 13, 15, in a vertical position, such block to be
of suitable height so that a series of them may be used in the space available
for such purposes, such blocks to have plain sides, and ends, with the exception
that a fillet 1 moulded along the top and bottom of each side of block, or by a
projecting lip on the outside of the top only longitudinally so that when the said
blocks are placed on the top of each other a recess or projection, as the case may be,
is formed whereby bricks (s) of suitable size and thickness may be inserted to form
and conduct the flow of furnace gases in a course similar to the tube arrangement g
before mentioned, the incoming atmospheric air passed through the vertical pas-
sages () moulded and formed in the blocks (r) forming the division of the flues, as
before described, and thus the air will pass from the lower part of the recuperator
to the upper collecting chamber (h) in the manner before described.
A combination of tubes (g) and perforated bricks (e) can be utilized as shewn in
Figs. 9 & 14 for the same purpose as the before mentioned blocks (r).
The principle of traversing effluent gases, covering of secondary air passages

page_text: from external radiation, covering recuperator with arch or tiles as shewn, and
utilization of waste heat in steam raising for heating purposes are carried out in
exactly the same way in each case.
In this specification it is to be understood that any of the before mentioned
special tiles, tubes or quarries, or the method of utilizing the same may be used
severally or collectively as is found most, desirable.
At the foot of Sheet 2 of the drawings (Figs. 19 to 26) accompanying this
specification I have illustrated various forms of, what in the specification, I have
called tiles, tubes and quarries, and each of these individual parts bears the reference
letter given them in the specification and drawings.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I déclare that what I
claim is:-
1. In metallurgical and other like furnaces the arrangement of fire clay pipes g
together with the method of traversing the atmospheric air around passages a in
the manner substantially as herein shewn and described.
2. In metallurgical and other like furnaces the arrangement of rows of fireclay
tubes placed in a horizontal or vertical: position whereby the waste furnace gases
from the oven, muffle or kiln may be passed on their way to the exit flue or chimney
in a zig zag manner from front to back and back to front of recuperator all
arranged and operating substantially as herein described and illustrated.
3. In metallurgical and other like furnaces the arrangement of pipes n, o, p, p
for the purposes described.
Total hi 19th
T
1000