IMPROVEMENTS IN THE MEANS AND APPARATUS FOR THE PURIFICATION OF GAS MANUFACTURED FROM COAL, CANNEL, SHALE, AND LIKE MATERIALS
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by William Cleland at the Office of
the Commissioners of Patents, with his Petition, on the 7th June
1875.
I, WILLIAM CLELAND, of Linacre, in the County of Lancaster,
Manager of Gas Works, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MEANS AND APPARATUS FOR THE
PURIFICATION OF GAS MANUFACTURED FROM COAL, CANNEL, SHALE, AND LIKE
MATERIALS," to be as follows:-
This Invention relates to the purification of gas from coal, cannel,
shale, and like materials, commonly called coal gas, and consists-
First. In treating lime, oxide of iron, or other material used in the
purification of coal gas, so as to bring such material into the condition
of porous pellets or nodules easily permeable by the gas, such pellets or
nodules having, when filled into the purifier, spaces or passages between
them of sufficient size to allow of easier passage by the gas than when
such material is not so treated. To accomplish the above I separate the
fine particles from the mass by sifting, screening, or like means; such
fine particles are then preferably slightly moistened and rescreened."

page_text: The above operation is repeated until the desired quantity of pellets or
nodules is obtained. When lime is the material treated I prefer that it
should be first slaked and damped in the usual way. Purifiers charged
with material prepared as above described may be of smaller area and
greater depth, or they may contain deeper tiers of the purifying
material, or a greater number of tiers may be used in the same vessel,
and this in consequence of the reduced resistance offered by material so
prepared to the passage of the gas.
'
Second. In employing waste heat from the retort bed or beds to
calcine lime to be used in the purification of gas. The limestone or
other suitable mineral is placed in suitable kilns, ovens, flues, or
receptacles, with or without fuel, and the hot gases from the retorts are
directed so as to heat the exterior of such kilns or receptacles, or such
gases are passed through, over, or in contact with the said mineral, so as
to raise it to a calcining heat and bring the lime into the caustic
state.
Third. In restoring the purifying power of waste lime or lime that has
been spent or fouled in the purification of gas by employing waste heat
from the retorts, with or without extraneous fuel to burn, expel,
separate, decompose, or otherwise change the impurities derived from
the gas, so as to restore the lime wholly or partly to the caustic
condition.
Fourth. In mixing carbonate of lime or other suitable mineral with
the waste lime_to be treated as above described, with or without fuel, in
order that the heat of the burning sulphur and other combustible
impurities derived from the gas may assist in calcining the lime mineral.
In the second, third, and fourth improvement the draught is assisted, if
necessary, by a steam jet or other exhausting or blowing apparatus.
:
Fifth. In placing in the vertical pipes of such a condenser or purifier,
as is described in the Specification of an Invention for which I obtained
Her Majesty's British Letters Patent, dated 28th May 1870, No. 1560,
when used as a primary condenser, what I call a "bottle brush" of
wood, iron, or other suitable material, having its radiating bristles,
spines, or arms, so arranged that the liquors condensing or falling
thereon shall drop from one to the other, and so descend the pipes
without clogging or choking. The above described form of condenser,
which I call the slow speed or scrubbing condenser, performs the

page_text: part of a purifier, washer, or scrubber, to a greater degree than
heretofore.
Sixth. In directing on to the above "bottle brush" placed in the
vertical or nearly vertical columns of any gas condenser, the liquors or
any desired part of the liquors condensed during the passage of the gas
from the retorts to the brush.
By the above arrangement of parts the gas and liquor are well
broken up and brought into more intimate contact, so as to increase the
scrubbing effect, remove a larger quantity of impurities, and improve
the quality of the gas.