IMPROVEMENTS IN MANUFACTURING GAS, AND IN APPARATUS CONNECTED THEREWITH
Year: 1857

page_text: LETTERS PATENT to Frank Clarke Hills, of Deptford, in the County of
Kent, Manufacturing Chemist, for the Invention of "IMPROVEMENTS IN
MANUFACTURING GAS, AND IN APPARATUS CONNECTED THEREWITH."
Sealed the 19th June 1857, and dated the 31st March 1857.
PROVISIONAL SPECIFICATION left by the said Frank Clarke Hills at
the Office of the Commissioners of Patents, with his Petition, on the
31st March 1857.
I, FRANK CLARKE HILLS, of Deptford, in the County of Kent, Manu-
facturing Chemist, do hereby declare the nature of the Invention for "IM-
PROVEMENTS IN MANUFACTURING GAS, AND IN APPARATUS CONNECTED THEREWITH,"
to be as follows:-
Under the ordinary mode of manufacturing gas large quantities of smoke
and impure gases escape from the retorts into the retort houses, and from
thence into the outer air; and the object of my improvements is as far as
possible to prevent such escape, and to keep the retort houses as cool and free
from smoke and impurity as possible. My improvements will, perhaps, be best
understood by shewing the difference between them and the ordinary mode of
working. Thus, in drawing the coke in the ordinary manner from the retorts

page_text: some of the coals are not perfectly converted into coke, and tar is deposited in
the mouth-piece of the retort, and on opening the door of the retort the
admission of air causes a good deal of smoke and impure gas to escape from
the retort, and the same escape takes place when the retort is charged, also
in clearing the ascension pipe by a hot iron or otherwise much smoke and im-
purity escape into the retort house.
Now, my first improvement is to prevent as far as possible this escape
of smoke, &c. into the retort house, and this I effect by placing a hood in
front of the mouth-piece of each retort, which hood should rise a few inches
above the top of the retort, but having the front of the hood as low or
a little lower than the inside top of the retort, so as to form an inverted
box or pocket to receive the smoke, &c. which may escape from the retort.
The sides of the hood should come down as low as the bottom of the retort.
At the upper part of the hood (which may be made of cast or wrought
iron, and of .any convenient form,) a pipe is placed (of sufficient capacity
to take off all the smoke, &c. generated) to connect the hood to the flues
or fire spaces of the bed of retorts. This pipe is to be furnished with a
valve or slide to open or close the connection between the hood and the flues
at pleasure. The ash-pit of the furnace heating the retorts is to be furnished
with a door, and each retort or bed of retorts is to have a damper to regulate
the draft into the main flue to the chimney. These matters being thus
arranged, when the retort is charged or uncharged the valve of the connecting
pipe from the hood to the fire flues is to be opened as well as the damper into
the main flue, and the ash-pit door is to be closed. By this means a sharp
draught will be caused through the hood and connecting pipe, which will draw
any smoke or impure gases that may escape from the retort when the door is
removed (either in charging or uncharging it) into the red-hot fire spaces or
flues of the retort bed, and when the smoke, &c. will be burnt or consumed.
After the retort or bed of retorts is charged, the valves of the connecting pipes
from the hoods are to be closed, and the damper to the main flue is also to be
closed to the ordinary working draught, and the ash-pit door is to be opened.
If enough draught can be obtained without closing the ash-pit or altering the
damper to the main flue, then there will be no necessity for these points being
attended to; but in most cases it will be best to work as above directed.
Instead of connecting the hoods to the flues or fire spaces of the beds of
retorts, they may be connected to a separate flue leading to a chimney that
has sufficient draught, or sufficient draught may be caused by revolving
fans or other mechanical means to draw the smoke and gases from the
Louds, which said smoke or gases may be afterwards passed into a chimney

page_text: or condenser, but taking the smoke, &c. into the flues of the retort beds is
preferred.
My next improvement is to prevent tar or tarry matter from being condensed
or deposited in the mouth-piece of the retorts, as it usually is in the ordinary
way of working, and which, coming in contact with the hot coke, which is
drawn over it from the retort, causes much smoke, &c. I prevent this deposit
of tar to a great extent, if not wholly, by having the bottom of the mouth-piece
of the retort made to slope inwards from the door to the red-hot part of the
retort, so that any tar that may condense in the ascension pipe or mouth-piece
will run down the inclined plane from the door on to the red-hot part of the
retort and be converted into coke or cinder, and the mouth-piece being thus
free from tar, little or no smoke will be made when the hot coke is drawn
through it. A gutter or inclined plane may also be fixed on the door of the
retort under the ascension pipe to carry any tar that may drop into it on to
the red-hot part of the retort, and the ascension pipe should project a little.
into the inside of the mouth-piece to deliver the tar into the gutter or inclined
plane without running down and contaminating the inside of the mouth-piece;
should any tarry matter, however, remain in the mouth-piece of the retort when
the door is opened, it should be absorbed with a little fine breeze dust, and be
scraped out before withdrawing the coke. The mouth-piece of the retort should
be kept as hot as it can be worked without causing a stoppage in the ascension
pipe, and this may be effected by lining the mouth-piece either inside or out
with brickwork.
My last improvement is to cool the coke with lime water instead of common
water, which will to a considerable extent prevent the escape of sulphuretted
hydrogen and sulphurous acid gas, which takes place when common water is
used.