IMPROVEMENTS IN THE CONSTRUCTION, SETTING, AND WORKING OF GAS RETORTS, AND IN THE PIPE APPENDAGES CONNECTED THEREWITH
Year: 1881

page_text: LETTERS PATENT to George Anderson, of Great George Street, in the City of
Westminster, for an Invention of "IMPROVEMENTS IN THE CONSTRUCTION,
SETTING, AND WORKING OF GAS RETORTS, AND IN THE PIPE APPENDAGES
CONNECTED THEREWITH."
"
PROVISIONAL SPECIFICATION left by the said George Anderson at the
Ottice of the Commissioners of Patents on the 18th June 1881.
GEORGE ANDERSON, of Great George Street, in the City of Westminster.
"IMPROVEMENTS IN THE CONSTRUCTION, SETTING, AND WORKING OF GAS RETORTS,
AND IN THE PIPE APPENDAGES CONNECTED THEREWITU."
According to this Invention I construct from fire bricks two or more gas retorts
side by side and parallel with one another, as hereinafter described.
I also construct similar retorts from fire clay.
Where the pipes by which gas is led from the retorts into a pipe common to all
the retorts, and which is usually called a "hydraulic main," 1 employ a junction
constructed, as hereinafter described, in such manner that the gas from each retort
may either be allowed to pass direct into the hydraulic main without having to dip
into the tar and ammonical liquor contained therein, or may be made to rise up
through those liquids in the ordinary manner as it enters the hydraulic main.
I also employ an additional main pipe or pipes laid on top of the retort benches
near to the hydraulic main to receive the gas from the latter, and keep it at a
moderately high temperature for some time before passing to the usual condensing
main or condenser.
"
The dumb plate of the furnace next to the furnace frame or door I form of a
hollow box of iron, which contains water to keep it cool.
I place the hydraulic main in a different position to what is usual, namely, in
through and through" retorts along the centre of the benches, or on single length
retorts, near to the back wall, instead of near the front of the retorts as is usual.
I also construct the line of pipe from each individual retort with a fall all tho
way from the hydraulic main to the retort,

page_text: I also form air passages in the solid brickwork of the furnace through which air
can be admitted from the exterior to the interior of the retort oven at pleasure to
convert any carbonic oxide gas that may be formed in the furnace into carbonic
acid, and ensure a more efficient and economical combustion of the fuel employed
to hent the retorts.
The retorts are to be charged and drawn every 3 or 4 hours, as hereinafter
described.
The ovens in which the retorts are to be set may be built of the usual form, but
I have found it convenient to make them narrower than usual, those represented
in the Drawing hereunto annexed being only 4 feet wide.
The furnace I construct in the usual form, and above it on each side of the oven
is built a range of pillars with flue spaces between, and on which the brick retort
rests.
The brick retort is constructed of bricks especially moulded for the purpose, and
consists of corner "lumps" that form the rest for the retort, the foundation for the
sides and the skew back for the arch that forms the bottom; it further consists of
side tiles which rest on the corner “lumps,” and at top form the skew back for the
arch that forms the top of the retort, and further consists of arch bricks that form
the bottom, and of deep bricks that form the key of the last named arch, and part
of the mid partition common to both the retorts, and also of "lumps" that rest on
the last mentioned "deep bricks," and at top form two skew backs, one on each
side, for the other side of the arches that form the top of both retorts.
Those lumps and bricks and tiles have a dovetail cut in them, as shown, to hold
the fire clay joint that make the retort staunch or gas tight.
When the materials of the brick retort are all set in their places and the retort
formed, pillars are built between the retort and the side wall of the oven, as shown
at Figure 3.
The heat ascends from the furnace through the spaces between these pillars.
The pillars are projected over the brick retort, as shewn in cross section at Figure 1,
and the next retort, which is a twin clay retort, rests on these pillars and on other
pillars which rise up from the centre of the brick retort.
When the twin clay retort is placed in position, the aforesaid pillars are built up
to about their middle, and the pillars are then connected by projecting bricks
which form a continuous horizontal wall d, Figure 1, to stop the heat from getting
any higher.
On the walls d, d, are carried up similar pillars, and other pillars are carried up
on the centre of the twin retort; on these latter pillars the upper ordinary clay
retort rests, and from the side pillars bricks or tiles project and butt against the
sides of the retort for the double purpose of forming a support to that retort
and for forming a flue underneath and above for the passage of the heat from tho
furnace.
In the construction of retorts and flues thus described the heat passes as
follows From the furnace it passes out below the bottom brick retort right and
left up between the pillars that support the brick retort against the side walls of
oven, through between the brick twin and the clay twin retort until it arrives at
12 to 18 inches from the back to those retorts, it then passes to the right and left,
up past the clay twin retort, the solid wall d, d, having been stopped off to allow
the heat to so pass up; the heat then passes over the twin clay retort and under
the tile that gives a side support to the upper clay retort towards the front, and
up to the upper side of the clay retort, the side supporting tile of the upper retort
having been stopped off 12 inches or so from the inside of the front wall to allow
the heat to pass up, thence the heat proceeds back along the top of the top retort
until it emerges through the arch of the oven as shown.
Other modes of arranging the flues may be adopted, the mode here described is
one that I have found to answer well.
The heat may now be allowed to pass to the chimney, as is ordinarily the case,
but I find it economical to pass the heat of two such ovens into a central oven

page_text: which is without a furnace, and in which I place retorts to be heated by the heat
from the ovens on each side of it, and what I have found best is to place in the top
of the central oven one thin clay retort which receives the first of the heat, and
underneath I place two cast iron retorts, the lower one forming the covering of a
flue into which the heat enters near the front, passes back below that retort and up
into a flue formed in the back wall, and thenco to the main flue and the chimney,
Bee Figures 6 and 7, Drawings No. 1 and No. 2.
The retorts in this central oven prefer to rest on rib arches, as shown, which
give a side support to the division wall and ensures stability of the structure for
the retorts over the furnace, see Figure 7.
I prefer to form air passages behind the bricks that form the sides of the furnace
for the double purpose of keeping those bricks cool, and also for admitting from
the outside some air to mingle with the gases passing froin the furnace, and ensure
the conversion of any carbonic oxide into carbonic acid and thus get an efficient
combustion of the fuel, and I give the gases this second atom of oxygen after they
have passed from under the brick retort, which from its close proximity to the
furnace is hot enough, and thus get the final combustion of the fuel among the top
retorts which are further away from the intense heat of the furnace, see x, x, x, x,
Figure 1.
I now proceed to describe the fitting up of the iron mountings.
The furnace frame and door is of the ordinary kind, but I substitute a hollow
iron box of the form shown at Figure 2, letter e, for the ordinary "dumb plato" of
brickwork or of solid iron which always burns away and permits the live fuel in
the furnace to approach the door, which it then speedly cracks and twists, and also
burns away the brick work in the vicinity, so causing the front of the furnace to bo
its wenkest part.
To the outer vertical side of this hollow dumb plate is attached a pipe which is
supplied with a small stream of water. This water fills the dumb plate at its
inner edge and prevents it getting beyond the heat of boiling water, and from the
holes pierced at its inner top edge, or from any other place, provision can be made
for allowing the water to drip down for the usual supply of the ashpit, by
which the dumb plate is kept cool and the supply of water to the ashpit is
continuous.
The "mouthpieces" to the brick as also to the clay twin retorts are cast in one
piece for each twin, and may be held by bolts in the ordinary manner or by
external binders, as shown on the elevation.
In erecting the "ascension" pipes and hydraulic main I prefer to place them as
shewn at Figure 2.
The hydraulic main is placed at the back of the retort beds instead of at
the front as usual, and the ascension pipe descends from there all the way to the
retort.
All the tar which condenses in this pipe will thus flow back into the retort,
instead of, as usual, much of it flowing into the hydraulic main, and it will thus be
converted into gas, and in order that it shall flow into the body of the retort and
not merely lie in the mouthpiece to be a nuisance when the retorts are "drawn," I
place the bottom of the mouthpiece slightly higher than the bottom of the retort,
and I give the retorts a fall of several inches from the front to ensure a fall for the
tar into the body of the retort.
The entrance of gas into the hydraulic main is effected through a box shewn at
Figures 4 and 5, drawn to an enlarged scale of 14" to a foot, in which there are
two pipes; ono dips into the liquid in the main as is usual, the other is cut short
nt the top of the hydraulic main, and is supplied with a 'valve ground to fit a face
and also dipping into a shallow cup of tar to ensure a gas tight joint. Figure +
shows the arrangement in its best form; Figure 5 shows its adaptation to existing
pipes and hydraulic mains.
When a retort has to be opened to remove the coke and receive a fresh charge,
the valve is let fall on its seat, which prevents a back passage of the gas. When the

page_text: retort is charged the valvo is lifted and the gas passes without having to dip into
the tar, which it usually does, and which is objectionable inasmuch as tar robs gas
of a portion of its alluminating power.
Instead of drawing the whole retorts of a "setting" at the same time or a
large number of them as is usually done, I charge, say, the right hand bottom
one of the brick retort and the left hand one of the clay retort in each of the
settings.
The next draw may be the whole of the top retorts, or it may be the other two
portions of the twin retorts.
"
By this modo of "charging
"
the retorts, first, by introducing smaller charges
of coal into each retort that will be "burnt off" in 3 hours, instead of larger
charges that require 6 hours, and second, in only charging one or two retorts of a
setting" at a time, instead of a large number or the whole of the retorts of a
"setting" at one time as is usual, I ensure a more uniform heat in the retorts,
which not only will contribute to their greater duration, but also contributes to a
larger yield of permanent gas from any given quantity of coal.
"
'
The retorts may be of other form or size than those described.
Before the gas passes from the hydraulic main to the condenser to be cooled, I
prefer to pass it in its crude state, first, into one or more lines of pipe laid as shewn
on the top of the retort benches, but sufficiently high to prevent the radiated heat
from being warm enough to convert the tar formed therein into pitch, sec
letters G, F, Figure 2.
The gas simply passes in at one end and out at the opposite end of those pipes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Anderson in the Great Seal Patent Office on the
16th December 1881.
GEORGE ANDERSON, of Great George Street, in the City of Westminster.
"IMPROVEMENTS IN THE CONSTRUCTION, SETTING, AND WORKING OF GAS RETORTS,
AND IN THE PIPE APPENDAGES CONNECTED THEREWITH."
"
According to this Invention I construct from fire bricks two or more gas retorts
side by side and parallel with one another, as hereinafter described.
I also construct similar retorts from fire clay.
Where the pipes by which gas is led from the retorts into a pipe common to all
the retorts (and which is usually called a "hydraulic main") I employ a junction
constructed as hereinafter described in such manner that the gas from each retort
may either be allowed to pass direct into the hydraulic main without having to dip
into the tar and ammoniacal liquor contained therein, or may be made to rise up
through those liquids in the ordinary manner as it enters the hydraulic main.
I also employ an additional main pipe or pipes laid on top of the retort benches
near to the hydraulic main, to receive the gas from the latter and keep it at a
moderately high temperature for some time before passing to the usual condensing
main or condenser.
The dumb plate of the furnace next to the furnace frame or door I form of a
hollow box of iron which contains water to keep it cool.
I place the hydraulic main in a different position to what is usual, namely, in
through and through" retorts along the centre of the benches, or on single length
retorts near to the back wall, instead of near the front of the retorts, as is usual.
I also construct the line of pipe from each individual retort with a fall all the
way from the hydraulic main to the retort.
I also form air passages in the brickwork of the furnace through which air can
be admitted from the exterior to the interior of the retort oven at pleasure, to
convert any carbonic oxide gas that may be formed in the furnace into carbonic
acid, and ensure a more efficient and economical combustion of the fuel employed
to heat the retorts.
The retorts are to be charged and drawn every 3 or 4 hours, as hereinafter
described.
The construction and setting of the retorts is illustrated in the Drawings
hereunto annexed.
Figure 1 shews a front elevation, one half in section, of a set of retorts, that
portion of the section which is marked No. 1 is taken on the line a, b, Figure 2, and
the portion of the section marked No. 2 is taken on the line c, d, Figure 4.
Figuro 2 is a cross section taken through the line e, f, Figure 1.
Figure 3 is a plan in section taken on the line g, h, n, o, p, r, Figure 1.
Figure 4 is a cross section taken on the line k, l, Figure 1.
Figure 5 is a cross section showing that the brick retorts and twin retorts may
be set in other ways than those shewn at Figures 1, 2, 3, and 4.
Figures 6 and 7 are views on a larger scale of the non-dip arrangement.
Figure 8 shews an adaptation of the non dip pipe to existing dip pipes and
hydraulic mains.
Figures 9 to 14 show views of the various parts of which the twin brick retorts
are formed. Figures 13 shew an arch brick of the lower arch of the twin brick
retort, and Figures 14 a brick of the upper arch or top.
The ovens in which the retorts are to be set may be built of the usual form, but
I have found it convenient to make them narrower than usual, those represented in

page_text: the Drawing hereunto annexed being only 4 feet 6 inches wide, but more retorts
and of either of the kinds shown may be placed in the larger ovens hitherto used.
The furnace I construct in the usual form, and above it on each side of the oven
is built a range of pillars with flue spaces between, and on which the brick retort
rests.
The brick retort is constructed of bricks especially moulded for the purpose, and
consists of corner "lumps" that form the rest for the retort, the foundation for the
sides, and the skew back for the arch that forms the bottom; it further consists of
şide tiles which rest on the corner "lumps," and at top form the skew back for the
arch that forms the top of the retort, and further consists of arch bricks that form
the bottom, and of deep bricks that form the key of the last named arch and part
of the mid partition common to both the retorts, and also of "lumps" that rest on
the last mentioned "deep bricks," and at top form two skew backs, one on each
side for the other side of the arches that form the top of both retorts. Various
views of these parts of the brick retorts are, as above stated, shewn at Figures 9
to 14.
"
The several lumps and bricks and tiles have a dovetail cut in their abutting
edges as shewn, to hold the fireclay joint that makes the retort stanch or gas
tight.
When the materials of the brick retort are all set in their places, and the retort
formed, pillars are built between the retort and the side wall of the oven, as shewn
at Figure 3, sections Nos. 1 and 3, the heat ascends from the furnace through the
spaces between these pillars. The pillars are projected over the brick retort, as
shewn in cross section at Figuro 1, and the next retort, which is a twin clay retort,
rests on these pillars, and on other pillars which rise up from the centre of the
.brick retort.
When the twin clay retort is placed in position, the aforesaid pillars are built up
to about their middle, and the pillars are then connected by projecting bricks which
form a continuous horizontal wall d, Figure 1, to stop the heat from getting any
higher.
On the walls d, d, are carried up similar pillars, and other pillars are carried up
on the centre of the twin retort; on these latter pillars tho upper ordinary clay
retort rests, and from the side pillars bricks or tiles project and butt against the
sides of the retort for the purpose of forming a support to that retort.
In the construction of retorts and flues thus described, the heat passes as
follows From the furnace it passes out below the bottom brick retort right and
left up between the pillars that support the brick retort against the side walls of
oven, through between the brick twin and the clay twin retort, until it arrives at
12 to 18 inches from the back of those retorts; it then passes to the right and left
up past the clay twiu retort, the solid wall d, d, having been stopped off to allow
the beat to so pass up; the heat then passes over the twin clay ictort and under
and over the tile that gives a side support to the upper clay retort towards the
front, and up to upper side of the clay retort, and it emerges through the arch of
the oven, as shewn near the front.
The heat may now be allowed to pass to the chimney as is ordinarily the case,
but I find it economical to pass the heat of two such ovens into a central oven
which is without a furnace, and in which I place retorts to be heated by the heat
from the ovens on each side of it; and what I consider best is to place in the top
of the central oven two thin clay retorts, which receive the first of the heat, and
underneath I place four cast iron retorts, the lower ones forming the covering of a
flue, into which the heat enters near the back, passes forward below these retorts,
and down into a flue formed underneath, and from thence up a fluo formed in tho
back wall, and thence to the main flue and the chimney, see Figures 3 and 4.
The retorts in this central oven I prefer to rest on rib arches, as shewn, which
give a side support to the division walls, and ensures stability of the structure for
the retorts over the furnace, see Figure 5, section No. 2.
I prefer to form air passages behind the bricks that form the sides of the furnaco

page_text: for the double purpose of keeping those bricks cool, and also for admitting from
the outside some air to mingle with the gases passing from the furnace, and ensure
the conversion of any carbonic oxide into carbonic acid, and thus get an efficient
combustion of the fuel, and I give the gases this second atom of oxygen after they
have passed from under the brick retort, which from its close proximity to the
furnace is hot enough, and thus get the final combustion of the fuel among the top
retorts, which are further away froin the intense heat of the furnace, see x, x, x, x,
Figure 1, section No. 1.
The twin clay rotorts are forined in the same way that ordinary clay single
retorts are now made.
When using built up twin retorts or twin clay retorts, other modes of arranging
the flues may be adopted, so it be that the retorts are evenly heated, as, for
example, the arrangement of retorts and flues shown at Figure 5 may be adopted.
I now proceed to describe the fitting up of the iron mountings.
The furnace frame and door is of the ordinary kind, but I substituto a hollow
iron-box of the form shown at Figure 2, letter e, and on an enlarged scale
immediately above that Figure for the ordinary "dumb plate" of brickwork or
of solid iron, which always burns away and, permits the live fuel in the furnace
to approach the door, which it then speedily cracks and twists, and also burns
away the brick work in the vicinity, so causing the front of the furnace to bo its
weakest part.
To the outer vertical side of this hollow dumb plate is attached a pipe at e',
which is supplied with a small stream of water. This water nearly fills the dumb-
plate, and provents it getting beyond the heat of boiling water, and from its outer
top edge e² or from any other place provision can be made for allowing the water
to drip down for the usual supply of the ashpit, by which the dumb plate is kept
cool, and the supply of water to the ashipit is continuous.
The "mouth pieces" to the brick as also to the clay twin retorts are cast in one
piece for each twin, and may be hold by bolts in the ordinary manner or by
external binders.
In erecting the "ascension" pipes and hydraulic main I prefer to place them as
shewn at Figure 2.
The bydraulic main is placed at the back of the retort beds instead of at the
front as usual, and the ascension pipe descends from there all the way to the
retort.
All the tar which condenses in this pipe will thus flow back into the retort
instead of, as usual, much of it flowing into the hydraulic main, and it will thus be
converted into gas; and in order that it shall flow into the body of the retort, and
not merely lie in the mouth piece, to be a nuisance when the retorts are
"drawn,"
I place the bottom of the mouth pieco slightly higher than the bottom of the retort,
and I give the retorts a fall of several inches from the front to ensure a fall for the
tar into the body of the retort.
The entrance of gas into the hydraulic main is effected through a box, shewn at
Figures 6 and 7, drawn to an enlarged scale of 1/" to a foot, in which there are
two pipes, one dips into the liquid in the main, as is usual, the other is cut short
at the top of the hydraulic main, and is supplied with a valve ground to fit a face,
and also dipping into a shallow cup of tar to ensure a gas tight joint. Figures 6
and 7 shew the arrangement in its best form, Figure 8 shows its adaptation to
existing pipes and hydraulic mains.
When a retort has to be opened to remove the coke and receive a fresh charge,
this valvo is let fall on its seat, which prevents a back passage of the gas. When
the retort is charged the valve is lifted, and the gas passes without having to dip
into the tar, which it usually does, and which is objectionable, inasmuch as tar robs
gns of a portion of its illuminating power.
Instead of drawing the whole retorts of a "setting" at the same time, or a large
number of them, as is usually done, I charge, say, the right hand bottom one of the

page_text: brick twin retort, and the left hand one of the clay twin retort in each of the
settings.
The next "draw" may be the whole of the top retorts, or it may be the other
two portions of the twin retorts. By this mode of " charging by introducing
smaller charges of coal into each retort that will be "burnt off" in 3 hours, instead
of larger charges that require G hours, and second, in only charging one or two
retorts of a "setting" at a time instead of a large number, or the whole of the
retorts of a setting at one time, as is usual, I ensure a more uniform heat in
the retorts, which not only will contribute to their greater duration, but also
contributes to a larger yield of permanent gas from any given quantity of coal.
The retorts may be of other form or size than those described.
"
Before the gas passes from the hydraulic main to the condenser to be cooled I
prefer to pass it in its crude state first into one or more lines of pipe laid as shewn
on the top of the retort benches, but sufficiently high to prevent the radiated heat
from being warm enough to convert the tar formed therein into pitch, see letter F,
Figure 2.
The gas simply passes in at ono end and out at the opposite end of those pipos.
I find from workings of the retorts as described that I make 10 per cent. more
gns per ton of coal, and more than that in saving of retort house, and without any
diminution of illuminating power, and the charge of coal being only about two
thirds the weight of a usual charge, the work is much easier for the men.
The twin retorts shewn at Figures 1 to 4 are lying on their longest diaincter,
but in some modes of setting it may be advisable to place them as shewn on
Drawing Figure 5.
Having thus described the nature of my said Invention and the manner of
performing the sanie, I would have it understood that I claim,—
First. The combination of retorts and furnaces, substantially as herein before
described with reference to Figures 1 to 4.
Second. The twin retorts of brick or moulded fire clay, substantially as
described.
Third. The hollow dumb plate supplied with water for the furnaces of gas
retorts, substantially as described.
Fourth. The means shewn to abolish the "dip" and the modified arrangement
of these means to adapt them to existing dip pipes.
In witness whereof, I, the said George Anderson, have hereunto set my hand
and scal, this Sixteenth day of December, in the year of our Lord One
thousand eight hundred and eighty one.
GEORGE ANDERSON. (S.)