Improvements in the Construction of Retorts and Apparatus for the Destructive and Cumulative Distilation, Carbonizing, and Calcining of Dry Compound Substances.
Year: 1886

page_text: Date of Application, 7th Oct., 1886.
Complete Left, 11th June, 1887.
Complete Accepted, 5th Aug., 1887.
Improvements in the Construction of Retorts and Apparatus for
the Destructive and Cumulative Distilation, Carbonizing, and
Calcining of Dry Compound Substances.
I WILLIAM BURNS of 32 Elmwood Terrace Leith in the County of Mid Lothian,
Consulting Engineer, and Chemist, do hereby declare the nature of this invention to
be as follows:-
I construct a metal retort lined with some refractory material such as fire clay or
other refractory material. These retorts may be of any convenient size or form,
provided with gas tight doors at top and bottom. It is convenient and preferable to
make the body of the retort cylindrical or slightly conical with a conical bottom, and
a horozontal mouth piece with valve, and dome shaped top. In the bottom end, I fix
a cylindrical neck piece with valve on bottom and a horozontal mouth piece with gas
tight doors fitted to the side of the neck piece. The neck and horozontal mouth piece
forms the furnace of the retort. At about the level of junction of the cylindrical
body and the conical bottom, I fix in the centre of the retort a smaller vertical
double cylinder, on which rests a smaller vertical concentric cylindrical pipe of metal,
which forms between them an annular steam space.
The double pipe is carried up through the centre of the retort and fitted with a
steam tight lid on the top of the dome, through which a piston rod works. To the
bottom end of the piston rod I fix a hollow cylindrical piston perforated with a
number of small air holes, and made of sufficient length to reach from the bottom of
the fixed internal cylinder to the junction of the neck piece with the conc. The piston
is made to move easily up and down inside the fixed internal cylinder. From
the top of the retort an eduction pipe is connected with proper condensers. Into the
mouth piece I insert an air pipe in connection with an air engine or blower, for the
purpose of feeding the furnace and retort with air of any required pressure or speed.
I likewise insert a steam pipe into annular space forined by the double cylinder and
connecting pipe, so as to allow high pressure steam to be blown from the bottom of
the internal cylinder through the incandescent fuel.
I fix the retort in a vertical position in masonry so as to allow of a passage for men
and waggons under the neck piece. The complete apparatus I name the Cumulative
Piston Retort.

page_text: The mode of operating with the above described Cumulative Piston Retort is as
follows: The piston is lowered from the internal cylinder to the neck-piece and forms
a continuous flue or tube from the neck to the top of the retort, and by lifting the lid
on the top of the pipe it forms a vent for air and gas to escape, I then charge the
retort through the charging doors on the top and sides with the substance to be
distilled, which substances are prevented from falling into the neck by the perforated
piston. I then charge the neck-piece with fuel from the mouth piece. The fuel may
be either coal, coke, charcoal, wood, or peat, the choise of the fuel will depend upon
the substance to be distilled. Having charged the furnace with a sufficient quantity
of fuel and kindeled it the draught up through the central pipe soon makes the whole
burn brightly, I then close the door of the mouth piece and also the lids on the top of
the retort, and turn on a blast of air from the blower, which forces the hot gases
of combustion through the substances in the body of the retort, I then turn on a jet of
high pressure superheated steam into the annular space formed by the double cylinder,
from which it is distributed over the incandescent fuel and drives off the gases from
the substances undergoing distilation.
These gases and vapours are conducted from the top of the retort into suitable
condensers.
As soon as the distilation is completed the charcoal and spent substances in the
retort is discharged from the neck by removing the lid and raising the perforated
piston into the internal-cylinder which allows the spent substances to drop into
wa aggons and be removed with the greatest case.
The novel feature of this mode of distilation by the Cumulative Piston Retort, is
as follows
1st. The furnance is placed inside the retort instead of outside as is usually done.
2nd. The use of a central concentric cylinder and hollow perforated piston for
distributing the hot gases and steam in the centre of the retort.
3rd. The products of combustion and hot gases are utilized by forcing them through
the substances to be distilled with a blowing machine or by an exhausting engine,
which equalizes the temperature throughout the whole mass, which cannot be done by
external heat applied in the usual manner.
4th. Any substance can be distilled under any required temperature or pressure by
regulating the quantity of fuel and speed of blast.
5th. By this mode of distilation the valuable products of distilation are increased
with a great saving of fuel.
These retorts are superior to any other for extracting oils, gases, and salts, from
compound substances, and for economising fuel by utilizing the hot gases produced
by combustion, by forcing the gases through and among the substances to be distilled,
and extracting from such substances a greater amount of valuable products than is
produced by any other form of retort.
Dated this Sixth day of October 1886.

page_text: Improvements in the Construction of Retorts and Apparatus for
the Destructive and Cumulative Distilation, Carbonizing, and
Calcining of Dry Compound Substances.
I WILLIAM BURNS of 32 Elmwood Terrace Leith in the County of Mid-Lothian
Consulting Engineer and Chemist, do hereby declare the nature of my invention for
IMPROVEMENTS IN THE CONSTRUCTION OF THE AFORESAID RETORTS AND APPARATUS
FOR DESTRUCTIVE DISTILATION and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
Referring to the accompanying plan; Fig. 1 is a vertical section of the retort and
condenser. Fig. 2 is a vertical elevation at right angles to Fig. 1, with the front of the
condenser removed to shew the ends of the air pipe N, and shewing the position of
the charging doors T, T. Fig. 3, is a horizontal section through the line A. B. shewing
the plan of the conical bottom and ribs. Fig. 4 is a section through E F shewing the
steam distributer Z. The shell of the retort may be made of cast iron and bolted
together in sections, or it may be made of boiler plates riveted together and lined with
fire brick or other refractory material.
These retorts may be made of any convenient size or form. It is convenient and
preferable to make the body of the retort cylindrical or slightly conical with a conical
hottom and dome shaped top as shewn in section by K, K. In the bottom end, I fix
a cylindrical neck piece G. having a valve W, on the bottom, and a horizontal
mouth-piece g, with gas tight doors fitted to the side of the neck-piece G.
The neck-piece G, and, and the horizontal mouth-piece q, form the furnace of the
retort. Inside the furnace G I fix a steam superheater i. In the centre of the retort
at about the level of the junction of the cylindrical body K¹ and the conical bottom K,
1 fix a smaller vertical double cylinder H, on which rests a smaller concentric cylinder
or pipe of metal which forms between them an annular space I for steam. The double
pipe is carried up to the top of the retort, and the centre pipe passes through the dome
to a sufficient height to allow the bend Q with the valve Y to be fixed on the side of
the central pipe. The central cylinder H and the vertical pipes are supported in their
position by the arched ribs Z, and a communication is formed between the annular
steam space I, I, and the hollow ribs Z, which are perforated with a number of small
holes for the steam to be distributed equally through the mass in the retort.
Inside the cylinder H, I suspend a hollow cylindrical piston J, perforated with a
number of small air holes; the piston is made to slide easily up and down inside the
fixed cylinder H, the suspending piston rod passes through a stuffing box V on the
top of the retort; the piston rod is attached to suspending chain which passes over the
wheels V, VI, and the whole is balanced by the counter-weight, R. S is a steam pipe
inserted into the annular space I of the central pipes and is connected with a steam
boiler. S¹ is a steam pipe from the boiler inserted into the steam superheater i. From
the top of the retort the eduction pipe L, is connected with the condenser M;

page_text: the end of the pipe L, dips into the basin m, which, is filled with tar,
through which the gases and hot vapours are forced, and condensed by the cold
air passing through the horizontal pipes N. The tar and oil collect in the tank O, at
the bottom of the condenser and the uncondensed gases escape by the valve U, which
can be regulated to any required pressure. The condenser is enveloped in an
air chamber P, P, into which air is forced by an air engine or blower. The air
chamber P, P, is connected with the furnace by the pipe X.
The mode of operating with the above described retorts is as follows. The piston J
is lowered from the internal cylinder H to the neck-piece and forms a continuous tube
or flue from the neck to the top of the cylinder as shewn in the section Fig. 1, by
lifting the lid Y on the top of the bend it forms a vent for air and gas to escape.
I then charge the retort through the charging doors T. T. and fill the retort up to the
bottom of the dome with the substances to be distilled. The contents in the retort are
prevented from falling into the neck or furnace by the perforated piston J, I then
charge the furnace G, from the mouth-piece g. The fuel may be coal, coke, wood
charcoal peat or sulphur, the choice of fuel will depend on the nature of the substance
to be distilled. Having charged the furnace with a sufficient quantity of fuel and
kindled it, I then inject a blast of steam into the annular space I. 1. which heats the
central pipe and causes a strong draught through the furnace and up the central pipe
and makes the fuel in the furnace burn brightly. I then close the doors and mouth-
piece, and fix the lids on the top of the retort, at the same time I turn a blast of air
from a blower into the furnace; the air enters the chamber by the pipe Pand then.
passes through the horizontal pipes N in the direction shewn by the arrows. The
cold air condenses the hot vapours in the condenser and the vapours heat the air as it
passes through the pipes; the hot air is conducted to the furnace by the pipe X and
forces the hot gases of combustion through the substances in the body of the retort,
I then turn a jet of high pressure steam from the pipes S, S¹, into the annular
spaces I, I, i, from which the steam is distributed over the incandescent fuel from a
number of small holes in the sides of the ribs Z and from the top of the superheater i
in the furnace G, which drives the gases and volatile vapours from the substances
undergoing distilation. These gases and vapours are forced through the condenser M,
and escape by the valve U, and are led into the boiler furnace and consumed; or the
gases may be further condensed; and otherwise utilized. As soon as the distillation
is completed the charcoal, or other spent substances in the retort, is discharged from
the neck by opening the valve W, and raising the perforated piston J. into the
cylinder H, which allowes the spent residue to drop through the neck into waggons
beneath and to be removed with the greatest ease. When coal or shale is distilled in
these retorts for the sake of the oil and ammonia; the furnace should be charged
with coal and the contents distilled at low temperature that is at a dull red heat and
the vapours and gases should be passed through a surface condenser under high
pressure so as to effect rapid condensation. (The meaning of high pressure in this
specification is any pressure above 2 lbs. on the square inch.)
The remainder, that is the uncondensed gases should be passed through a saturated
solution of salt, (chloride of sodium) which absorbs the remainder of the ammonia
and part of the carbonic acid, and form bicarbonate of soda and chloride of
ammonium as by-products. The unabsorbed gases should finally be passed into the
boiler furnace.
If it is desired to distil coal for the sake of the coke, (the tar and aminonia being
by products). The coal should be distilled under low pressure; in that case instead of
forcing the air through the furnace by a blower the air should be drawn through by
an exhauster and the gases condensed as above.
When the distillation is for the purpose of producing heating gases it should be
conducted under high temperature and low pressure.
When wood, sawdust, or peat, is to be distilled for the tar and acetic acid, The
furnace should be charged with wood and kept at low temperature, and the vapours
should be passed through suitable condensers at high pressure. When pyrites is the
substance to be distilled the furnace should be charged with sulphur or incandescent

page_text: charcoal, and the sublimed sulphur condensed in proper condensing chambers, and the
sulphurous acid should be conducted into chambers for manufacturing sulphuric acid.
In this case the pyritus should be distilled under low pressure and no steam should
be injected into the retort. Lime and cement should be distilled in these retorts under
low pressure with a large supply of superheated steam.
These retorts are well adepted for manufacturing black ash or crude carbonate of
soda. By furnacing the usual mixture of sulphate of soda lime and coal (used in the
Leblanc process) in these retorts a superior black ash can be produced and the whole
of the sulphur regenerated and save.
These retorts, instead of producing sulphide of calcium as is done in the ordinary
reverberating furnaces, produce sulphuretted hydrogen which can easily be decomposed
and the sulphur absorbed by peroxide of iron.
These retorts can also be used for the manufacture of sulphate of soda and
hydrochloric acid, at much less cost than by the ordinary method.
The method of using the retort for making sulphate, is as follows. The conical
bottom K is filled with pyrites up to the junction of the cylindrical body, and the
requisite quantity of salt is laid on the top of the pyrites, that is to say, there should
be one and a half of chloride of sodium to one of pyrites, and the furnace charged
with sulphur, or charcoal, and the air blast turned on, but one third of the air used
should be made to pass through the steam distributer Z, along with the steam; which
will decompose the salt and produce sulphate of soda and hydrochloric acid.
The acid should be collected in condensers of either glass, stone-ware, or lead.
The distillation may be conducted either under low or high pressure, the higher tho
pressure the quicker does the decomposition take place. These retorts can also be
economically used for making water gas for heating purposes.
The proportion of height to diameter of the retort must depend on the nature of
the substance to be distilled. For coal, shale, wood, peat, bones, lime, or pyrites, the
height ought to be from three to four times the diameter, and for furnacing black ash,
or making sulphate of soda the height should not be more than one diameter.
The novel features of distilling by these retorts are as follows.
1st. The furnace is placed inside the retort instead of outside as is usually done.
2nd. The use of a central concentric cylinder and hollow perforated piston in the
centre of the retort for distributing the hot gases and steam through the substances to
be distilled.
3rd. The products of combustion and hot gases are utilized by forcing them by a
blowing engine or exhausting machine, through the substances to be distilled which
equalizes the temperature throughout the whole mass, which cannot be done by
external heat applied in the usual manner.
4th. Any dry substance can be distilled or calcined under any required pressure or
temperature by regulating the quantity of fuel, and speed of the blast.
5th. By the use of these retorts in destructive distillationthe most valuable pruducts
of distillation are increased, and these retorts last much longer than retorts that are
heated by an external furnace. These retorts are superior to any others for extracting
oil and gases from compound substances, and for making good furnace coke, also for
economising fuel by utilizing the hot gases of combustion by forcing the gas through
and among the substances to be distilled, and extracting from such substances a
greater amount of valuable products than is obtained by any other form of retort.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is ;
1st. I claim the making and fixing of a double central cylinder with with a con-
centric steam space shewn at H in section and supported on arched hollow ribs Z
inside a verticle retort, the arched ribs having a number of small steam holes on the
sides and communicating with the steam space of the central cylinder. The central
cylinder to have a moveable hollow cylindrical piston perforated with a number of
small air holes and suspended by a rod passing through the top of the central pipe.
2nd. I claim the fixing on the bottom of the retort, an internal furnace, with gas

page_text: tight doors on the bottom of the retort and horizontal mouth-piece, and connected
with the piston and cylinder in such a manner as to form a continuous flue from the
bottom of the furnace to the top of the retort, having safety valves, all as shewn in
section by the letters G, J, I, Q, Y, V, and particularly described in the foregoing
specification.
3rd. I claim the heating of the air for feeding the furnace, by forcing the air
through the tubes of a multitubular condenser where the vapours from the retort are
condensed.
4th. I claim the particular form of condenser with horizontal tubes and enveloping
air chamber as shewn in section by the letters M, N, O, P.
5th. I claim the use of the retort for the purpose of distilling any dry compound
substance as described in the foregoing specification, either under high or low
pressure, or under high or low temperature, with or without the addition of steam as
may be desired.
Dated thin 10th day of Tu1004