Furnaces for Heating Gas Retorts.
Year: 1892

page_text: Date of Application, 13th June, 1892
Complete Specification Left, 13th Mar., 1893-4ccepted, 22nd Apr., 1893
PROVISIONAL SPECIFICATION.
Furnaces for Heating Gas Retorts.
I, ROBERT BRUCE ANDERSON, A.K.C., A.M.I.C.E., of 35 Great George
Street, in the City of Westminster, do hereby declare the nature of this invention
to be as follows:-
The object of this invention is to enable gas works where the retorts are
worked from the ground floor to employ a gas producing furnace as has been
recently done in gas works where the retorts are worked from a stage 6 to 8 feet
above the floor and having a deep space below the retorts into which the gas
producing furnace has been placed.
I place the furnace inside the retort oven pretty much in the position where
the ordinary furnaces have hitherto been, but I make the furnace deeper and
sink the ash pan a little below the level of the floor, than has usually been the
practice.
The chief passages for the admission of air commence near the floor level a
little higher than the furnace bars. It is at this level that the furnace bricks
are most apt to be destroyed, by excessive heat and clinker that forms on theni
and by robbing these bricks of some of the heat I not only heat the air but
also preserve the bricks.
I
These lower passages communicate with an air channel formed in the back
wall of furnace and deliver the hot air into the furnace above the level of the
top of the fuel.
Should it be found that hot air is required to enter the furnace nearer the
front this is provided by forming two air passages in the side walls of furnace
at about the level of the top of lower retort, on each side of the furnace.
Means are provided so that the admission of hot air can be regulated both as
to quantity and position of introduction to the furnace by partially or wholly
closing the outer ends of these air passages.
I
The outer end of the furnace is made to project in front of the retorts so that
the coke from the two upper retorts or as much of it as is required can be
drawn red hot from the retorts and run down the slope into the furnace.
prefer that these two upper retorts should be drawn one at a time and with an
equal lapse of time between each so that a charge of red hot coke can be run
into the furnace every 2 or 3 hours, according to the time occupied in burning
off a charge of the retort.
Hot air may also be provided from pipes fixed in the flues conveying the heated
gases passing up to the chimney.
The primary air for the furnace is admitted in the front between iron steps and
may also be admitted underneath the furnace bars as is usual.
The spaces between the iron steps can be partially closed off by damp coke
breeze being laid on them and to preserve the iron steps from destruction a small
stream of water is let on to the upper one from thence it falls to the steps below
and finishes in the ash pan or pan.
The front of the furnace and the ash pit may be closed off by doors through
which the amount of air entering can be regulated.
The heated gases from the furnace pass over and under through between the
upper retorts and over the back bridge of furnace and under the two lower retorts
towards the front where it passes at right angles and traverses along the under side
of those retorts and up flues formed in the back wall of the oven, each of those
vertical flues being provided with a damper to regulate the flow of gases to either
[side as may be desired.

page_text: In working the furnace it is filled with red hot coke to a depth of about 4 feet
and the furnace mouth closed off with coke breeze or an ordinary door may be
used and the depth of fuel in the furnace should not be allowed to get below
18 to 24 inches, before more fuel be supplied.
When the furnace requires to be cleaned out or clinkered, some temporary
furnace bars are run over the lower iron steps and on to a level projection on
the back wall, this keeps the fuel above them from falling lower. The furnace
bars are removed, the clinkering done, bars again replaced when the temporary
bars are removed and the fuel sinks on to the furnace bars.
Dated this 13th day of June 1892.
R. B. ANDERSON.
COMPLETE SPECIFICATION.
Furnaces for Heating Gas Retorts.
I, ROBERT BRUCE ANDERSON, A.K.C., A.M.I.C.E., of 35* Great George
Street, in the City of Westminster, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
The object of this invention is to enable gas works where the retorts are worked
from the ground floor to employ a gas producing furnace as has been recently done
in gas works where the retorts are worked from a stage 6 to 8 feet above the floor
and having a deep space below the retorts into which the gas producing furnace
has been placed.
I place the producer inside the retort oven pretty much in the position where the
ordinary furnaces have hitherto been, but I make the furnace deeper and sink
the ash pan a little more below the level of the floor, than bas usually been the
practice.
The chief passages for the admission of air commence near the floor level a little
higher than the furnace bars. It is at this level that the furnace bricks are most
apt to be destroyed, by excessive heat and clinker that forms on them and by
robbing these bricks of some of the heat. I not only heat the air but also preserve
the bricks.
These lower passages pass along the side cheeks of the producer and deliver
heated air to the producer gases which pass off from the top of the producer and
effect the combustion of these gases within the furnace. Hot air may also be
supplied through other heated passages.
The primary air for the producer is admitted in the front between iron steps and
may also be admitted underneath the furnace bars as is usual. The furnace bars
may be left out altogether and the fuel so be supported on the solid hearth, the
primary air supply then mostly passing through between the steps at the front.
The primary air supply can be controlled by a shutter in a door or doors covering
the front of the ash pit, also by partially closing the spaces between the iron steps
by putting on to the steps some fine coke breeze which is kept moistened by a
trickle of water kept running on to the top step falling thence from step to step
into the ash pit so preserving these steps from being burnt.
In the drawing annexed I have shewn various ways in which my invention may
be carried out. In one construction shewn in cross section in Figure 1 and in
longitudinal section in Figure 2 the gases are consumed just as they pass off from
the top of the producer.
In the construction shewn at Figures 3, 4, 5, 6, 7 and 8 the gases passing from
the producer are conducted to the lower part of the setting before being consumed.
Figures 6, 7 and 8 shew the producer adapted to settings of 5, 4 and 2 retorts.
In Figures 1 and 2, A is the retort oven-B the retorts-C the gas producer
placed inside the oven-D the bars on which the fuel rests-E iron steps between
which air is admitted from the front to the fuel-F doors for closing the mouth of

page_text: the ash pit and for allowing only a limited supply of air to pass to the producer.
As will be seen from Figure 2 the producer is made to project somewhat outwards
from the front of the oven and an opening is formed through the front wall just
above the top of the producer to allow of the producer being filled with fuel.
Hare air passages formed along the lower part of the side walls of the producer
leading from the front into the lower part of the hollow interior of the wall I which
is at the back of the producer. JJ are openings in the upper part of the front of
the back wall to allow heated air to pass to the gases which rise up from the pro-
ducer and effect their combustion. KK are air passages formed along the upper
part of the side walls of the producer leading from the hollow in the back wall to
openings K¹ to allow of heated air passing to the gases to be consumed at points
nearer to the front of the furnace. The heated products arising from the com-
bustion of the gases pass upwards and then downwards amongst the retorts and at
the front enter flues L which open into outlet flues at the back, or be conducted in
any other usual manner through the setting.
In the construction shown at Figures 3, 4 and 5 which is the one I prefer the
letters refer to corresponding parts; in it the producer C is closed over at the top
by blockings placed between the upper retorts and by carrying the backwall of the
producer up to them or the blockings may be omitted and instead the backwall
carried up to top of oven and the gases arising from the producer are led downwards
through the hollow back wall I to a horizontal passage M (through openings M¹)
in the top of which they rise up into the combustion chamber to be consumed.
The air passages H deliver at their rear end into passages H¹ which are on either
side of the passage M and the heated air is allowed to pass into the combustion
chamber through openings formed in the top cover of these passages.
The gas and air passages may be covered with loose covering tiles which may be
set nearer to or further away from one another to control the combustion. When
the circumstances of the case will not admit of doors being provided through which
one can actuate the loose cover tiles when the setting is at work I carefully space
these tiles in constructing the setting so as to have an equal combustion throughout
the setting by having the openings smaller at the end next the producer than those
at the remote end. If desired a further admission of air to the interior of the
passages H¹ may be made through pipes or channels placed in flues through
which the waste heat is conducted as shewn at N in the various figures.
The products of combustion rise up amongst the retorts and are allowed to pass
off in any of the ordinary ways.
In Figures 3, 4 and 5 they are shewn to be led into outlet flues in which are
placed pipes N which may be used for affording a further supply of hot air for
combining with the gases arising from the producer. The front portions of the
upper retorts are heated by radiation from the solid incandescent fuel in the pro-
ducer and should this be found insufficient means may be provided by a damper
tile O for allowing some of the producer gases to pass off and be consumed amongst
them.
Figures 6, 7 and 8 are cross sections shewing the producer adapted to settings
of 5, 4 and 2 retorts the letters having similar significations and similar producers
may be used with other numbers of retorts in a setting, they may also be used with
settings of through retorts in which case I prefer to put one producer for each
through setting with the gas and air channels extending from the back of the
producer throughout the remainder of the oven. Also one producer may be used
to heat more than one oven.
In working the producer it is filled full with hot coke and the charging door
closed off with damp coke breeze which cakes to a crust and does not fall down as
the fuel below is consumed, or it may be closed with an ordinary door. The depth
of fuel in the producer should not be allowed to get below 18 to 24 inches before
more fuel be supplied.
When the furnace requires to be cleaned out or clinkered, temporary furnace
bars are inserted over one of the iron steps and on to a projection in the backwall

page_text: which keep the fuel above from falling when the permanent furnace bars are
withdrawn, the clinkering is then done, furnace bars replaced and temporary bars
removed when the fuel sinks down on to the permanent bars.
I prefer to make the producer and its grate area as large as the oven will admit
so as to cause a sluggish current of primary air to pass through which is favorable
to the production of carbonic oxide.
A hopper G such as shewn in Figure 2 with inclined bottom may also be formed
on the top of the projecting portion of the producer to permit of coke being run
direct into the producer as it is drawn from the upper retorts.
I prefer that the upper retorts should be drawn separately with equal intervals
between each so that a portion of the contents of each retort may be run into the
producer every few hours according to the time occupied in the roasting of a
charge in the retorts.
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. Furnaces for heating gas retorts constructed with a gas producer inside the
body of the retort oven to allow of a gas producer being used at the same time
that the retorts are worked from the ground floor level substantially as described.
2. The construction of furnaces for heating gas retorts substantially as herein-
before described and illustrated at Figures 1 and 2.
3. The construction of furnaces for heating gas retorts substantially as herein-
before described and illustrated at Figures 3, 4 and 5, and also as illustrated in
Figures 6, 7 and 8.
Dated this 13th day of March 1893
R. B. ANDERSON.