IMPROVEMENTS IN APPARATUS USED IN THE MANUFACTURE OF GAS, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO BOILER AND OTHER FURNACES
Year: 1872

page_text: LETTERS PATENT to Robert Porter, Mechanical Engineer, and Thomas
Lane, Civil Engineer, both of 172, Fenchurch Street, in the City of
London, for the Invention of "IMPROVEMENTS IN APPARATUS USED IN
THE MANUFACTURE OF GAS, PARTS OF
WHICH IMPROVEMENTS ARE
APPLICABLE TO BOILER AND OTHER FURNACES.”
ALSO
Sealed the 31st May 1872, and dated the 23rd February 1872.
PROVISIONAL SPECIFICATION left by the said Robert Porter and
Thomas Lane at the Office of the Commissioners of Patents, with
their Petition, on the 23rd February 1872.
We, ROBERT PORTER, Mechanical Engineer, and THOMAS LANE, Civil
Engineer, both of 172, Fenchurch Street, in the City of London, do
"IMPROVEMENTS IN
hereby declare the nature of the said Invention for
APPARATUS USED IN THE MANUFACTURE OF GAS, PARTS OF WHICH IMPROVEMENTS ARE
ALSO APPLICABLE TO BOILER AND OTHER FURNACES," to be as follows:-
This Invention relates to improvements in apparatus for the manu-
facture of gas, and is based upon an Invention for which we obtained

page_text: in which the
Some part or
Letters Patent, No. 201, dated January 25, 1871, and
charge is passed through the retort by means of a screw.
parts of the present Invention however are applicable to heating retorts
as at present constructed or arranged, and for boiler and other furnaces.
The object of the Invention is the more perfect carbonization of the
materials submitted to distillation, and to the economy effected by the
improved form of furnace.
The apparatus consists of a cylindrical retort fixed vertically upon a
coke box or receptacle for the exhausted charge, and to the upper end of
the retort we attach a hopper or reservoir for containing a supply of coal
or other suitable gas making material. Both the hopper and coke box
are in communication with the retort, and each of them is provided with
a lid made gas tight by luting or otherwise. Through the hopper and
the retort we fit or suspend a central shaft with the upper end projecting
through the top of the hopper, and upon the said shaft at or near the top
of the retort we fix a worm or screw for feeding the charge into the
retort. Below the screw upon the same shaft we fix another worm or
screw extending throughout the retort, the threads or blades of which
screw are made to slope or shelve downwards, preferably at an angle of
about 45 degrees towards the sides of the retort, whereby the charge is
caused to slide down the said sloping blades of the screw, and lie in the
angle formed by them and the sides of the retort.
We construct the lower screw in a vertebrated form, that is, in a
number of separate lengths or sections, each section having a central
hollow boss. The bosses are notched or fitted together so as to bear upon
or clutch one another, and admit of a number of them being strung
together upon the central shaft, to which they are secured, and thus form
one continuous screw; or where found more convenient a washer may be
inserted between each or any section of the screw to break the continuity
of the thread. The screw may be made of iron, clay, or other suitable
material, and if preferred it may be formed all in one piece. The screw
is turned with an axial motion by means of suitable gearing communi-
cating with the central shaft, so as to carry the charge gradually from
the hopper through the heated retort, and thence discharge it into the
coke box below.
We also in some cases fix the retort either horizontally or in an
inclined position with a hopper and coke box slightly modified from that

page_text: herein-before described for the vertical retort, and within the retort we
fix a screw of similar construction to that already mentioned, but with
the blades or thread of the screw made to project at right angles to the
axis of the screw; we also make the said screw to continue throughout
the length of the retort, so that when it is turned it causes the charge to
be moved along the lower side of the retort from the hopper and into the
coke box.
For feeding the charge into the retort, whether vertical, horizontal, or
inclined, we sometimes use a screw lying in a horizontal pipe attached
to the neck of the retort, which screw is actuated by suitable gearing.
By this arrangement we are enabled to work the feeding apparatus
independently of the screw in the retort. The retort may thus be
removed from its setting without disturbing the feeding apparatus. The
rate of feed may also be regulated by extending or contracting the orifice
between the hopper and the retort, or by other suitable means.
In constructing the furnace for heating the retorts herein-before
described, or for heating retorts set horizontally in the ordinary manner,
for the more easy removal of clinker or scoria, and for the better
preservation of the sides of the furnace, we fix an iron dead surface
around the sides and back of the furnace at or about the level of the
grate bars, and all round at the outer edge of the said dead surface we
form an upright web, from the top of which a flange projects outwards
from the grate, the whole presenting in section a form somewhat
resembling the letter Z. Upon the flange just mentioned we build the
inside lining of the furnace, and also provide beneath a space for the free
admission of air and of steam from the evaporating pan around the said
dead surface bars to preserve them from the action of the heat. We
prefer to use these dead surface bars in connection with an elevated arch
forming a space for a combustion chamber above the level of the flues
leading into the oven in which the retorts are set.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Robert Porter and Thomas Lane in the Great Seal
Patent Office on the 23rd August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT

page_text: PORTER, Mechanical Engineer, and THOMAS LANE, Civil Engineer, both
of 25, Birchin Lane, in the City of London, formerly of 172, Fenchurch
Street, in the same City, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of February, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Robert Porter and Thomas Lane, Her
special licence that we, the said Robert Porter and Thomas Lane, our
executors, administrators, and assigns, or such others as we, the, said
Robert Porter and Thomas Lane, our executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN APPARATUS USED IN
THE MANUFACTURE OF GAS, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO
BOILER AND OTHER FURNACES," upon the condition (amongst others) that we,
the said Robert Porter and Thomas Lane, our executors or adminis-
trators, by an instrument in writing under our, or their, or one of their
hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Robert Porter and Thomas Lane,
do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described, and ascertained
in and by the following statement, reference being had to the accom-
panying Drawings and to the letters and figures marked thereon, that is

page_text: furnaces.
The object of the first part of this Invention is the more perfect
corbonization of the materials submitted to distillation in the manu-
facture of gas.
The apparatus constituting the first part of the Invention consists of a
cylindrical or slightly taper retort (or retorts) fixed vertically upon a coke
box or receptacle for the exhausted charge, and to the upper end of the
retort we attach a hopper or reservoir for containing a supply of coal or
other suitable gas making material. Both the hopper and coke box are
in communication with the retort, and each of them is provided with a
lid made gas tight by luting or otherwise. In the hopper or reservoir
we fit or suspend a central shaft which extends throughout the retort
and reservoir, the upper end projecting through the top of said reservoir,
so as to allow a toothed wheel to be keyed thereon. At or near the top
of the retort or lower part of the reservoir we fix a worm or screw for
feeding the charge into the retort. In lieu of a screw it may be found
sometimes more convenient to attach a plug, boss, or thick disc of metal
to the shaft, the disc having a hole made eccentrically to its axis, and
furnished with a peg. Below the screw, disc, or other suitable means
for feeding the retort, and upon the same shaft is fixed another worm or
screw extending the whole length of the retort, the threads or blades of
which screw are made to slope or shelve downwards, preferably at an
angle of about 45 degrees towards the sides of the retort, to cause the
charge to slide down the said sloping blades of the screw, and lie in
the angle formed by them and the sides of the retort. The threads
or blades of the screw may be made of one uniform pitch throughout
its length, but in some cases it may be found more advantageous to
construct the first two, three, or more turns of a finer pitch than the
rest.
The lower or main screw is constructed preferably in a number of
separate lengths or sections, each section having a central hollow boss.

page_text: thread.
The screw may be made of iron, clay, or other suitabe material,
and if preferred it may be formed all in one piece. The screw is turned
with an axial motion by means of suitable gearing communicating
with the central shaft, thus carrying the charge gradually from the
hopper through the heated retort, from whence it is discharged into the
coke box below.
We may in some cases fix the retort either horizontally or in an
inclined position with a hopper and coke box slightly modified from that
herein-before described for the vertical retort, and within the retort a
screw of similar construction to that already mentioned is fixed, but with
the blades or thread of the screw made to project at right angles to the
axis of the screw; and we make the said screw to continue throughout
the length of the retort, so that when it is turned it causes the charge to
be moved along the lower side of the retort from the hopper and into the
coke box.
For feeding the charge into the retort, whether vertical, horizontal, or
inclined, we sometimes use a screw lying in a horizontal pipe attached
to the neck of the retort, which screw is actuated by suitable gearing.
By this arrangement we are enabled to work the feeding apparatus inde-
pendently of the screw in the retort, and to vary the rate of feed. This
arrangement has also the advantage of admitting of the retort being
removed from its setting without disturbing the feeding apparatus.
feed may also be regulated by extending or contracting the orifice
between the hopper and the retort.
The
The second part of the Invention consists in constructing the furnace
for heating the retorts, herein-before described, or ordinary horizontal
retorts in a manner to facilitate the removal of clinker or scoria to
secure economy of fuel and the preservation of the sides of the furnace.
For this purpose we fix an iron dead surface around the sides and back
of the furnace at or about the level of the grate bars, and all round at the
outer edge of the said dead surface we form an upright web, from the top
of which a flange projects outwards from the grate, the whole presenting
in section a form resembling the letter Z. Upon the flange just men-
tioned we build the inside lining of the furnace, and also provide beneath
a space for the free admission of air and of steam from the evaporating
pan around the said dead surface bars to preserve them from the action
of the heat. We prefer to use these dead surface bars in connection
with an elevated arch forming a space for a combustion chamber

page_text: above the level of the flues leading into the oven in which the retorts
are set.
In order that the foregoing description may be more easily understood
Drawings of the apparatus are attached hereto, of which the following
is an explanation, the same letters indicating like parts in the different
views:-On Sheet 1, Fig. 1, is a sectional elevation of the apparatus as
we prefer to construct it for use in large gas works, the section being
taken through C, D, of Fig. 2, which is a sectional plan following the
line A, B, through Fig. 1. In Fig. 1 E represents the hopper or
reservoir with its feed pipe E 2, which contains the coal or other gas
making material; F and F are retorts, F representing an iron retort,
and F one made of clay, the latter being shown partly in elevation and
partly in section; G is the coke box which receives the coke when dis-
charged from the retort; H is the central shaft carrying the short or
feed screw I, which draws or forces the coal into the retort; and J is
the main screw upon which the coal falls, and is lowered thereon through
the retort, and dropped into the coke box; J' represents a screw made
with a double thread, a form which may sometimes be adopted with
advantage; K is the open end of a pipe which serves to conduct the gas
into a hydraulic main K³, and L is the oven wherein the retorts F and
F are set; M, M, are flues in connection with the furnace N. At the
bottom of the sides of the furnace N the dead service plates R, R, will
be seen, and upon the upper flanges S, S, of these plates is erected the
fire-brick lining of the furnace. T, T, are the spaces contrived to admit air
and steam arising from liquid in the evaporating pan U to impinge
upon the under side of the dead surface plates, and maintain them in a
comparatively cool condition; a is the lid by which the mouth of the
coke box is closed. This lid is hinged on one side of the mouth piece,
and when closed is held in position by a catch b, which is pivotted at its
upper end, and furnished with a screw at its lower one. This screw on
being turned presses against the lid, and so retains it in close contact
with the mouth piece until it is intentionally released. The arrangement
is shewn in section at a where the lid is closed, and in elevation at c
where the lid is open.
The Drawings on Sheet 2 have reference to the form of apparatus we
prefer for use in small gasworks, or where the quantity of gas required is
limited. The arrangement is similar in principle to that already
described, and the letters of reference indicate the same parts. In

page_text: Fig. 4 however the letter O shews the outlet flue, which is marked in
dotted lines in Fig. 3, and P denotes the combustion chamber; V is a
screen of thin brickwork, which extends a short distance above the
bottom of the retort, and serves to protect it from the direct and con-
sequent intense heat from the flue M; W is the mouth piece to the
coke box, through which the coke is withdrawn; and X, the brickwork
surrounding the apparatus. It will be observed that in Fig. 3 the
screw J is shown partly in section, and partly in elevation.
The action of the apparatus is as follows:-The oven having been
heated, and the hopper or reservoir supplied with coal, the apertures to
the hopper and to the mouth piece of the coke box are closed. Motion
is then imparted either by manual, steam, or other power to the shaft H,
whereupon the coal is drawn, forced, or screwed into the retort, and falls
upon the blades of the main screw, where it lies in the angles formed
between the screw and the sides of the retort. A thin stream of coal is
thus brought into contact with the whole of the heated surface of the
retort; and in the course of its transit which takes place through the
continuous revolution of the screw from the top to the bottom the coal
is presented to the retort in a most favorable manner for its complete
distillation, the whole of the gas or volatile matter passing off through the
orifice K, and from thence to a hydraulic main, or other suitable
contrivance for conducting the gas away for its subsequent course of
manufacture and purification.
The application of the dead surface bars to boiler and other furnaces
is manifestly so simple as to need no illustration or further description.
Having now described and particularly set forth the nature of this
Invention, and the manner in which the same is or may be used or
carried into effect, we would observe in conclusion that we do not
confine or restrict ourselves to the precise details or arrangements which
we have described or referred to, as variations may be made therefrom
without deviating from the principles of this Invention; but what we
consider to be novel and original, and therefore claim as our Invention
is, —
First. Passing coal or other gas producing material through a vertical
retort in a thin stream which is kept in contact with the heated surface
of the retort, leaving the central portion of the retort free for the passage

page_text: Second. The apparatus consisting of a vertical retort F and a
rotating screw J with a sloping or inclined thread, for the purpose set
forth.
Third. Constructing the rotating screw in a number of pieces or
sections fitted together on the central shaft in such a manner that the
first or top section being secured to the said shaft the other sections will
rotate therewith as described.
Fourth. The dead surface plates constructed and arranged as described,
for the purpose set forth.
In witness whereof, we, the said Robert Porter and Thomas Lane,
have hereunto set our hands and seals, this Twenty-third day
of August, in the year of our Lord One thousand eight hundred
and seventy-two.