AN IM- PROVED METHOD OF MANUFACTURING GAS
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GRAFTON, of Cambridge, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fourth day of September, in the fifth year of. Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the the
said John Grafton, Her especial licence, that I, the said John Grafton, my
exors, admors, and assigns, or such others as I, the said John Grafton, my
exors, adiñors, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, and exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "AN IM-
PROVED METHOD OF MANUFACTURING GAS;" in which said Letters Patent is
contained a proviso, obliging me, the said John Grafton, by an instrument
in writing under my hand and seal, particularly to describe and ascertain
the nature of my said Invention, and in what manner the same is to be
performed, and to cause the same to be enrolled in Her said Majesty's High
Court of Chancery within two calendar months next and immediately after
the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Grafton, do hereby declare the nature of my said Invention to consist,
first, in the double retort, constructed as herein-after explained; secondly, in

page_text: a heat-retaining arch thrown over the said retort; thirdly, in an improved
decomposer; and, fourthly, in the application of an exhausting apparatus for
drawing the gas through the said decomposer. And in further compliance
with the said proviso, I, the said John Grafton, do hereby describe the manner
in which my said Invention is to be performed by the following statement
thereof, reference being had to the Drawings annexed, and to the figures and
letters marked thereon, similar letters being used to denote similar parts in
letters marked thereon, similar letters being used to denote similar parts in
aff the Figures (that is to say).
DECRIPTION OF THE DRAWINGS.
In Sheet No. 1, Figure 1 represents a longitudinal section of one of my
said double retorts with its heat-retaining arch over it. The retorts it will be
observed are built of fire brick, in the form of an oven, the end A of the
retort being separated from the end B by the central transverse division C.
There are two furnaces D, E, one under the front half of each retort, the
mouths of doors of the retorts F and G being fitted in the usual manner.
H, I, are the ordinary gas-escape pipes; and J is the heat-retaining arch,
furnished with two apertures K, L, communicating with the space above the
arch, and thence to the flue M; all which will be more clearly understood
when the cross sections are hereafter described. Figure 2 on this Sheet is a
plan of the foundation on which my said retorts are placed.
In Sheet No. 2, Figure 3 is the transverse section, before alluded to,
representing a stack of two double retorts. A, A are the retorts; D, D, the
fire bars; J, J, the heat-retaining arches; and M, M, the chimney flues. It
will be observed that there is a third retort and heat-retaining arch set in the
same stack, and to the left of the other two, shown in this Figure; this is in
fact, my improved decomposer, the gas being conveyed from the retorts into
the decomposer at N, and drawn out of it again through the burning coke
0, 0, 0, by means of an exhausting apparatus, as will be more clearly under-
'stood hereafter.
Figure 4 is a plan of the said third retort, showing how I convent it into
a decomposer. P, Q, R, are three longitudinal brick partitions reaching from
top to bottom of the retort, and the parts marked S are small transverse metal
divisions descending from the top of that part of the retort to within about
one-third of the whole height from the bottom, as shewn at S, N, Figure 3,
in this Sheet. But to return to the description of Figure 4. The
other impurities entering at T, find their way along the passage U, U, impeded
in its progress purposely by the divisions S into the passages V, V, V, (which
gas and

page_text: are filled with red hot coke or charcoal), following the course pointed out by
the arrows till it is drawn out at the exit pipe W by means of an exhausting
apparatus to which the said pipe W is attached. It is hardly necessary to
observe, that the coke at 0, 0, 0, at Figure 3 in this Sheet, is heated by the.
furnace, of which the fire bars are shown at X, which heating is accelerated
by a heat-retaining arch similar to that thrown over the
Figure 5 is an end elevation in outline of the
Figure 3.
gas retort,
stack represented at
Figure 6 is a plan of the said stack, showing the connecting pipes by
which the gas and other impurities are conveyed from the retorts into the de-
composer. And it may be as well here to state, that as that portion of gas only
that it evolved during about the first three hours after the retort has been charged
requires to be passed through the decomposer, depending on the state of the
heats or the quality of coal, my arrangement of pipes provides for shutting off
by means of valves each end of each double retort alternately from the
decomposer; while in order to correspond with this arrangement I charge all
the ends of the double retorts which are at one side of the stack first, and let
them work in connection with the decomposer for three hours, or thereabouts,
dependant on the nature of the fuel used and the heat employed;) before I
charge the ends of the double retorts at the other side of the stack. When
these last are charged, the communication previously opened between the
other end of the retort and decomposer is closed by means of the valve
before mentioned, and the new communication opened with the decomposer
from the end of the retort låst charged; the mode of effecting which I will now
explain by continuing my reference to Figure 6. Y, Z, are the two principal
mains, commonly called hydraulic pipes, one at each side of the stack, receiving
the gas in its impure state from the two ends of the retort. a, b, c, d, e, and f
are six valves; g is the pipe leading into the decomposer at the part marked T
in Figure 4. By this arrangement of the smaller pipes g, h, i, j, and k, it will
be seen that if the valves a and d be open and all the others closed, and the
end of the double retort over which the main Y is situated be charged, the
gas arising from those ends of the retort will pass through the decomposer,
and be drawn out by means of the exhausting apparatus, herein-after ex-
plained, which is attached to the pipe at 1. When this state of things has
continued for about three hours, as before mentioned, I close the valve a, and
opening the valves b and c, the gas from this end of the retort is thereafter drawn
through the pipe h directly into the exhauster at / without passing through the
decomposer; I then charge the other end of the retort over which the main or

page_text: hydraulic pipe Z is placed, and opening the valve f, allow the gas evolved from
the newly charged ends of the retort to be drawn through the decomposer in
its turn for about three hours, when I close the valve f, and opening the valve
e, allow the whole of the gas from both ends of the retort to pass through the
pipe into the exhausting apparatus, until I am ready to recharge that end of
the retort under the main Y, when the operation just described of the valves is
to be repeated. It may be as well here to state that I prefer working the
heats so that a six hours' charge of the retorts shall be sufficient to carbonize
the coals, and as each batch of retorts will be charged alternately, and the
first three hours' produce of each charge pass through the decomposer, the
latter will always be in operation. At the pipe is inserted in a box, shewn at
Figures 12, 13, and 14, Sheet No. 2, a shield of fine wire gause, to prevent
accident from the ignition of the gas in the pipes by neglect of the valves.
On Sheet No. 3 an exhausting apparatus, for the purposes before mentioned,
is represented by four Figures, two sections and two plans, and as the particular
kind of exhausting apparatus itself forms no part of my claim to Invention, but
only the application of any suitable exhausting apparatus for the purpose afore-
said, it will be sufficient, in reference to the Figures on this Sheet, to state that
the induction pipe m is that which must be connected with the pipe l, shewn
in Figure 6, Sheet 2, while the eduction pipe n leads into the main P, whence
the gas passes into the purifier; the exhaustion in the apparatus here shewn
being caused by the revolution of the cranks, marked T, working the lever
beams, marked t, they raising the gasometers, marked z, which fall again by
their own weight, the up strokes causing the exhaustion, and three gasometers
being used to cause a continuous exhaustion. Now, it is evident that the
improved decomposer, before described, by means of a proper arrangement of
connecting pipes and valves, may be applied to the mains of any stack of
ordinary retorts; but I have found it desirable in some cases, where the works
are small, to adopt a different arrangement, as shewn in Sheet No. 4, where,
in Figure 7, x, x, represent a chamber or oven, built one over each end or half
of the double retort.
Figure 8 is a cross section, more clearly shewing this arrangement; 'x being
the decomposer over the retort, which is filled with red-hot coke, the matter
distilled in the retort below passing through slots y, y, in the roof of the retort,
over which slots finely perforated tiles are placed. Figure 9 is an end view of
the stack in outline; Figure 10, a plan of the foundation which supports the
retort; and Figure 11, a plan of the bottom of the decomposer; g, h, being two
slide valves over holes in the top of the retort, one of which is shown dotted in

page_text: under the valve h. These valves, g, h, are opened alternately to the decom-
poser x.
In this plan, Figure 11, I have shown the perforated tiles applied
to the bottom at one end of the decomposer, and the appearance of the slots at
the bottom of the decomposer at the other end with the tiles removed. When
the decomposer is thus placed over the retort, and built as it were in one with
it, the bottom of the decomposer always forming the top of the retort, the pipes
and valves, shown in Figure 6, Sheet No. 2, are not required. The object of
these slides g, h, is to admit of the escape of the gas after the expiration of the
first three hours, as aforesaid, without passing through the coke with which the
decomposer is charged. The opening and shutting of the apertures is effected
by the slide, the handle of which passes through the mouth-piece.
Now, whereas I claim as my Invention,―
First, the manufacturing of gas in what I call double retors, arranged in
manner herein-before described;
Secondly, in increasing the heat of such retorts by the application of a heat-
retaining arch, as herein-before described;
Thirdly, the passing of the gas through a decomposer either detached, and of
the kind shewn at Figures 3, 4, 5, and 6 on Sheet No. 2, or combined with
the retort, as shown on Sheet No. 4;
Fourthly, the application of an exhausting apparatus to the decomposers, to
facilitate or compel the passage of the gas through the said decomposers,
together with the wire gauze guard, herein-before described, interposed between
the exhausting apparatus and the pipe 7;
And such my Invention, being to the best of my knowledge and belief
entirely new, and never before used within that part of Her said Majesty's
United Kingdom of Great Britain and Ireland called England, Her said
Dominion of Wales, or Town of Berwick-upon-Tweed, I do hereby declare
this to be my Specification of the same, and that I do verily believe this my
said Specification doth comply in all respects fully and without reserve or
disguise with the proviso in the said herein-before in part recited Letters
Patent contained; wherefore I hereby claim to maintain exclusive right and
privilege to my said Invention.
In witness whereof, I, the said John Grafton, have hereunto set my
hand and seal, this Third day of November, in the year of our Lord
One thousand eight hundred and forty-one.
JOHN
(L.S.) GRAFTON.

page_text: AND BE IT REMEMBERED, that on the Third day of November, in the
year of our Lord 1841, the aforesaid John Grafton came before our said Lady
the Queen in Her Chancery, and acknowledged the Specification aforesaid, and
all and every thing therein contained and specified, in form above written.
And also the Specification aforesaid was stamped according to the tenor of
the Statute made for that purpose. .
Inrolled the Third day of November, in the year of our Lord One
thousand eight hundred and forty-one.