IMPROVEMENTS IN APPARATUS USED IN THE MANUFACTURE OF GAS.
Year: 1873

page_text: LETTERS PATENT to John Greaves Hawkins, of the Gas Works,
Sheffield, in the West Riding of Yorkshire, for the Invention of
IMPROVEMENTS IN APPARATUS USED IN THE MANUFACTURE OF GAS.
Sealed the 28th March 1873, and dated the 18th January 1878.
COMPLETE SPECIFICATION filed by the said John Greaves Hawkins
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 18th January 1873, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GREAVES HAWKINS, of the Gas Works, Sheffield, in the West Riding of
Yorkshire, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
APPARATUS USED IN THE MANUFACTURE OF GAS," and have petitioned Her
Majesty to grant unto me, my executors, administrators, and assigns,
Her Royal Letters Patent for the same, and have made solemn
Declaration that I am the true and first Inventor thereof.

page_text: NOW KNOW YE, that I, the said John Greaves Hawkins, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed in and by the following
statement, reference being had to the accompanying Drawings, and to
the letters and figures marked thereon.
This Invention has for its object the relieving of the retort from
unnecessary pressure when used for carbonizing coal or other material
for the production of gas, and ensuring a self-acting seal when the
retort is not actually employed in making gas. The Invention consists
in furnishing the hydraulic main with apparatus of which the following
is a description:-The dip pipe is made with a socket and flange on the
outside of the hydraulic main, and on the inside of the said hydraulic
the dip pipe is increased in diameter to admit of the introduction of
another pipe presently to be described. On one side of the dip pipe
which is within the hydraulic there is an opening in it, around this
opening there is a projection or flange cast on to the dip pipe, so that a
flat plate working or lying against the planed surface of the flange may
be made water and gas tight; attached to the plate just mentioned is a
curved pipe which passes through it, one end entering through the
opening before mentioned into the dip pipe while the other ascends on
the outside of the dip but within the hydraulic main; the plate is kept to
its seat by the aid of springs fastened to the dip pipe, and to the top of
the plate is fixed a rod which passes through the outer flange of the dip
pipe to the outside of the hydraulic main and terminates in a screw and
nut. By this means the height of the plate and consequently the
curved pipe which it supports may be adjusted with great nicety. It is
to be observed however that the upright part of the curved pipe which
enters the dip pipe is somewhat shorter than the corresponding one on
the outside of the pipe, this curved pipe being in fact like a dwarf
inverted syphon with one leg shorter than the other.
In order that the foregoing may be more easily understood, Drawings
are attached hereto of which the following is a description :-Fig. 1 is a
longitudinal section of part of the hydraulic main showing the dip pipe
and my improvements in the apparatus connected therewith; Fig. 2 is
a transverse section of the hydraulic main through A, B, Fig. 1; and
Fig. 3 is another transverse section through C, D, also of Fig. 1. In
Fig. 1, E is the socket and F the outer flange of the dip pipe, G is the

page_text: dip pipe a part of which is drawn as broken away, in order to show the
arrangement and form of the curved pipe H, which is carried by
the plate I; J, J, are springs for keeping the plate I in close contact
with the flange round the opening in the pipe G; K is the rod by which
the plate and curved pipe are supported; and L is the nut for adjusting
or regulating the position of the curved pipe with regard to the water
line in the hydraulic main. Similar letters refer to the same parts in
each of the Figures.
The action of the apparatus is as follows:-The water being supplied
to the hydraulic to the height shown, the pipe G dipping down as
depicted and the curved pipe being full of water, the gas would upon
the retort being charged and set to work pass down the dip pipe and
escape from its bottom in the usual way, but inasmuch as the gas has a
less head of liquid to contend with if it passed through the curved pipe it
will force the water out of the said curved pipe into the body of the
hydraulic main, and maintain for itself a free passage so long as gas is
given off from the retort. The only pressure to which the retort is
subjected after the water from the curved pipe is forced out being equal
to a head of water corresponding to the difference in level of the liquid
in the hydraulic main and the top of the shortest leg of the curved pipe.
The moment the lid of the retort is taken off is taken off or the pressure in it
ceases from any other cause, the water in the dip pipe G will immediately
flow into and fill the curved pipe H, and thus effectually seal the
communication between the hydraulic main and the retort; it should
however be noted that in case the curved pipe by any unforeseen
occurrence becomes choked, the gas from the retort will pass down the
dip pipe and escape from the bottom into the hydraulic main in the
ordinary manner with no other disadvantage than that of having to
contend with a deeper seal.
It will be seen that in the Drawings the shortest leg of the pipe H has
a funnel shaped mouth in order that the sealing may take place more
expeditiously, and this form though not absolutely necessary is preferred.
The relative sizes of the various parts may be altered from those shown
in the Drawings, which have been drawn more particularly to illustrate
the principle of this Invention.
The advantages attendant upon the use of this improved apparatus are
a reduced pressure within the retort when at work, and consequently an

page_text: increased quantity of gas is obtained from a given quantity of coal,
while the liability to a choking of the retort by the deposit of carbon is
materially lessened if not entirely overcome; the action of the apparatus
is also automatic or self-acting, and is capable of being adjusted with
ease and great precision.
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, I would observe in conclusion that I do not confine
or restrict myself to the precise details or arrangements which I have
described or referred to, as variations may be made therefrom without
deviating from the principles or main features of this Invention, but
what I consider to be novel and original and therefore claim as my
Invention is, the construction and application of apparatus used in the
manufacture of gas wherein a curved pipe is inserted through the dip
pipe, substantially as herein described for the purpose herein-before
set forth.
In witness whereof, I, the said John Greaves Hawkins, have here-
unto set my hand and seal, this Seventeenth day of January,
in the year of our Lord One thousand eight hundred and seventy-
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