Improvements in Retorts for the Carbonisation of Wood and other Vegetable Substances, and the Drying of Manures, Sewage, Sludge, Peat, and other Substances and Products.
Year: 1891

page_text: Date of Application, 15th Oct., 1891-Accepted, 24th Dec., 1891
COMPLETE SPECIFICATION.
Improvements in Retorts for the Carbonisation of Wood and other
Vegetable Substances, and the Drying of Manures, Sewage,
Sludge, Peat, and other Substances and Products.
I, WILLIAM HADFIELD BOWERS of Brookfield Chemical Works Napier Street,
West Gorton, Manchester in the County of Lancaster Manufacturing Chemist,
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 invention relates to improvements in retorts for the carbonisation of wood
and other vegetable substances and the drying of sewage and manures in large or
small quantities, sludge-cake (which is the residuum left on the top of the filtre
bed when the sewage is filtered) peat, and substances and products generally
whether in their natural state or when reduced by any ordinary method of
condensation into a form convenient for being subjected to the action of the
retort.
According to the said invention the retort is constructed with two or more
parallel Blues extending in a longitudinal direction along and within the retort, and
lying one above the other, but both, or all as the case may be, fed by the same
furnace and finally discharging into the same outlet. For the purposes of more
particular explanation I assume that the retort is constructed with two such flues
but it will be understood that the number of flues may be increased to any number
that can be reached by the heat from the furnace.
The space immediately over each flue forms a chamber through which an endless
chain with bars at suitable intervals and of such width as to sweep the floor or
lower surface of the chamber and carried upon sprocket wheels, draws the substance
"the material,")
or product to be operated upon (and which I hereinafter refer to as
from the point where it is supplied to the retort along and over the upper flue to
the extremity of that flue where the material falls into a space between such
extremity and the sprocket wheel on to the chain as it runs below. The material
is then drawn by the chain in the reverse direction along and over the lower flue
until it falls over the extremity of that flue through any convenient aperture
The connection of the lower flue
provided for its discharge from the retort.
with the higher flue is effected by means of an elbow or outside flue at the point
most distant from the furnace. The sprocket wheels are placed in the same plane
with and outside each end of the upper flue at distances convenient for the proper
working of the chain and the fall of the material when it reaches the extremity of
the upper fluc.
The gas driven off during the process escapes by ordinary condenser pipes,
leaving the gas from each chamber to be dealt with in the ordinary manner.
By means of the foregoing arrangement the heat from a single furnace is utilised
to heat both the chambers, and the material as it is drawn through the lower
chamber is exposed to heat coming from abore as well as from below with the
result that labour and time, as well as fuel, are economised.
The hopper by which the material is fed to the retort is constructed with a
bottom, hinged at the side furthest from the direction in which the chain travels, so
as to fall downwards and on to the chain. As the bars of the chain successively
catch the lower edge of the hinged bottom they push the bottom onwards and
upwards and close wholly or in part, and as each bar passes clear from under the
edge the bottom falls back and so releases from the hopper a supply of the material
which falls on to the chain. The further passage of the material is regulated by
means of a check or regulator consisting of a metal plate placed in and extending

page_text: at right angles across the upper chamber at or near a point immediately beyond
the space beneath the hopper, but opposite to the side to which the bottom is hinged.
This plate hangs and works upon a rod which may or may not project through one
or both of the sides of the retort and to which may be fitted a lever by means
whereof the plate is raised or lowered as required to permit or regulate the passage
of the material. If desired the resistance of the plate may be automatically
regulated by a weight upon the lever.
The material is carried through and along each chamber by means of the successive
bars of the chain.
In order that my invention may be the more clearly understood, I will now describe,
by reference to the accompanying drawings a mode or manner of carrying the
same into practical effect, taking as an example a retort constructed with two flues
and two chambers only. It is to be understood that, as before stated, a greater
number of flues and chambers may be employed, and that the hopper and regulator
as described may be used for feeding any retort worked with an endless chain
passing longitudinally along the heating chamber or chambers.
Figure 1 represents the elevation of a retort constructed according to my said
invention.
Figure 2 is a sectional elevation of such a retort.
Figure 3 is a plan shewing the positions of the hopper, regulator with lever, and
the endless chain and sprocket wheels.
I prefer the endless chain so constructed but any equivalent incchanical arrange-
ment for carrying the material along the chambers may be adopted.
Referring to Figure 2 the heat passes from the furnace at the point A into and
through the lower flue in the direction indicated in the drawing, to the further end
of that flue whence it is carried by an elbow or outside flue into the upper flue
and so in the direction indicated, to the point B whence it is discharged into the
outer air.
The material being placed in the hopper C is allowed by the hinged bottom to
fall upon the endless chain which by means of the bars GG closes or partially
closes the bottom of the hopper and carries or sweeps the material against and
past the regulator H, which as the material has passed is again depressed either by
its own weight or by means of the lever K acting if necessary by means of the
weight L. The material is then carried or swept by the bars of the chain through
the upper chamber to the point M where it falls between the outer extremity of
the flue N and the sprocket wheel O, on to the chain as it enters the lower
chamber P and so is carried or swept in the reverse direction through the lower
chamber and between the upper flue and the lower flue, to the point Q at the
extremity of the lower chamber where it falls or is carried through a convenient
aperture into a receptacle or is otherwise discharged from the retort.
The gases evolved during the process are carried off by means of condensing
pipes R and R fitted at convenient points.
The retort is set and heated and the sprocket wheels are driven in the ordinary
manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
First. The application and employment in retorts for the carbonisation of wood
and other vegetable substances, and the drying of manures, sewage, sludge, peat,
and other substances and products of double or multiple flues constructed and
arranged in the manner described.
Second. The construction and employment in retorts for the purposes aforesaid
of a hopper with a hinged bottom actuated by means of the successive bars of an
endless chain in the manner hereinbefore described and illustrated in the accom-
panying drawings.
Thur. The construction and employment in retorts for the purposes aforesaid

page_text: of a check or regulator constructed, placed and actuated as described and
illustrated.
Fourth. The employment in retorts for the purposes aforesaid of a hopper, con-
structed and actuated as aforesaid in combination with a check or regulator
constructed, placed and actuated as aforesaid.
Dated this Fourteenth day of October One thousand eight hundred and
W. H. BOWERS.