A Method of Enriching and Increasing the Volume of Gas Obtained from Coal, and Utilising the Waste Heat from Retort Settings.
Year: 1889

page_text: Date of Application, 14th Nov., 1889
Complete Specification Left, 15th Sept., 1890-Accepted, 8th Nov., 1890
PROVISIONAL SPECIFICATION.
A Method of Enriching and Increasing the Volume of Gas Obtained
from Coal, and Utilising the Waste Heat from Retort Settings.
FREDRICK PRITCHARD Gas Works Huyton Quarry near Liverpool Gas Engineer
do hereby declare the nature of this invention to be as follows:-
This object is obtained by passing the gas produced in the ordinary retort setting
through a secondary retort placed immediately outside the arch of the oven, and which
is heated by the waste heat issuing from the bed of retorts previous to entering the
main flue or chimney.
The secondary retort may be of ordinary formation, but preferably in that of a web
diaphragm or annular retort, thereby obtaining any desired length of heated surface
for the gases to come in contact with.
Dated th; 1911 d
1000
COMPLETE SPECIFICATION.
A Method of Enriching and Increasing the Volume of Gas Obtained
from Coal, and Utilising the Waste Heat from Retort Settings.
I, FREDRICK PRITCHARD of The Gas Works Huyton Quarry near Liverpool, Gas
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My present invention has reference to what is known as the "Dinsmore" process
of manufacturing coal gas; in this process, the gas after leaving the ordinary retorts,
is passed through a secondary retort termned for convenience the "duct" wherein it is
heated, the object being the conversion of tar or tarry vapour into permanent gas ;
after leaving the duct, the gas is passed through a water-jacketted outlet pipe. In
order to obtain the best results it is necessary to regulate the temperature of the duct
within certain limits and it is also desirable to maintain the inlet end of the duct at a
higher temperature than the outlet end. The object of my present invention is to
provide an improved duct which shall be cheap, durable and efficient, and to so
arrange it in conjunction with the bed of retorts, that the conditions herein before
stated can be readily fulfilled, and further that the waste heat of the furnace gases
shall be utilised for heating the duct.
In the accompanying drawings which serve to illustrate my invention, my improve-
ments are shown applied to a bed of seven retorts; only such details of the bed and
retorts with their fittings are shown or referred to as are necessary or useful in
describing my invention; throughout the drawings, the same or similar parts are
denoted by the same reference figures and in the case of sections, the direction in
which they are viewed is indicated by the small arrows adjacent to the letters denoting
the plane of section.
Fig. I is a front elevation of the bed 3
Fig. II is a sectional elevation on the line A, A, of Fig. III;
Fig. III is a sectional elevation on the line B, B, of Fig. II and
Fig. IV is a sectional plan on the line C, C, of Fig. III, the duct being shown
above the plane of section.
1 are the retorts, their mouths 2 leading into the collecting chamber 3 through the
valves 4 operated by the external valve levers 5; these are all of usual or suitable
construction.
The duct 6 is preferably of cast iron and of rectangular cross-section as shown in

page_text: Fig. II; its front end is closed by the door 7 and it is divided by the diaphragm 8
which extends from the door almost to the back of the duct and is preferably cast
solid therewith; the details of the door 7 and the method of securing it are omitted as
these may be of any suitable construction.
The duct 6 is set above the arch of the bed sufficiently high to leave room beneath
the duct for the flue 9 and it communicates at its lower side with the collecting
chamber 3 through the inlet valve 10 operated by the lever 11, and at its upper side
it communicates with the water-jacketted outlet or ascension main 12. It will be
seen that the gas from the retorts can pass from the collecting chamber 3, through
the valve 10, into the duct 6, then along the duct from front to back below the
diaphragm 8, then from back to front over the diaphragm, up the water-jacketted
ascension main 12, down the descending main 13, through the anti-dip valve 23, into
the hydraulic main 14, and thence by the weir valve 15 to the foul main 16. When
it is not desired to pass the gas through the duct, the inlet valve 10 is closed and the
gas will then pass direct by the ascension pipes 24 to the hydraulic main; these
pipes 24 are sealed more deeply than the descending main 13, so that the gas will
always pass by preference through the duct when the valve 10 is open.
The arrangements for heating the duct are as follows:-The flue 17 which pierces
the arch of the retort setting communicates through the opening 18 with the flue 9
which partially envelops the duct and it communicates also with the pass-by flue 19
pass the damper 20; the pass-by flue 19 opens into the main flue 21 and so also does
the flue 9, past the damper 22. It will be seen that if the damper 20 be shut and 22
opened, the furnace gases after leaving the retort chamber will flow through the
flue 9 towards the main flue and so heat the duct 6; if on the other hand, 22 be
closed and 20 opened, the gases will pass direct to the main flue. The flue 9 does not
entirely envelop the duct, but extends up the sides thereof a little higher than the
diaphragm, so that the upper part is heated only by conduction, and in this way
the gas in flowing through the duct traverses a passage whose temperature falls from
the inlet to the outlet end. By adjusting the relative openings of the dampers 20
and 22 the temperature of the duct can be regulated as desired. The arrangements
described, in addition to effecting an advantageous distribution of temperature in the
duct, high at the inlet and lower at the outlet, and affording ready means of regulating
the said temperature, also effect considerable economy of fuel by utilizing some of the
waste heat of the furnace gases; moreover by removing the duct from the retort
chamber, room is left therein for an additional retort.
As stated, the duct is preferably made of cast iron, as it is a good conductor and
may be made much thinner than fire-clay; any other suitable material may be used
however if preferred.
The bench shown may represent a single ended bench, or one half of a double-ended
bench the course of the furnace gases is not material so long as the last course
is from back to front along the top of the retort chamber, and the blocking must
be arranged accordingly.
I do not limit myself to the precise details and arrangements shown, as they
may obviously be varied without departing from my invention; it is also to be
understood that I make no claim to heating coal gas after it leaves the retorts,
nor to the use of the water-jacketted ascension main 12, these being well-known,
but ;-
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
(1) In apparatus for manufacturing coal gas, in which the gas after leaving the
ordinary retorts, is heated in a secondary retort or duct, placing the said duct outside
of the retort chamber and heating it by the waste heat of the furnace gases which
leave the said chamber, substantially as and for the purpose set forth.
(2) In combination with a secondary retort or duct, wholly or partially enveloped
by a flue through which the waste furnace gases can flow, a pass-by flue and dampers

page_text: whereby the temperature of the said duct can be regulated, substantially as set
forth.
(3) The secondary retort or duct 6 having a diaphragm 8, substantially as and for
the purpose described and illustrated.
(4) In apparatus such as is berein set forth, the use of a duct divided by an
internal diaphragın, and partially enveloped by a flue through which the waste
furnace gases flow, whereby the inlet end of the duct is maintained at a higher
temperature than the outlet end, substantially as set forth.
(5) The combination and arrangement of the duct 6 with the flues 17, 9 and 19
and the dampers 20 and 22, substantially as and for the purpose described and
illustrated.
Dated this 13th day of September 1890.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool.