IMPROVEMENTS IN THE PROCESSES OF TREATMENT OF PEAT & OF THE HYDRO- CARBURETS IT CONTAINS, AND IN THE APPARATUS FOR THE SAME
Year: 1858

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office of the
Commissioners of Patents, with his Petition, on the 21st May 1858.―
A communication.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer & Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE PROCESSES OF TREATMENT OF PEAT & OF THE HYDRO-
CARBURETS IT CONTAINS, AND IN THE APPARATUS FOR THE SAME," to be as follows:-
At the present time, when the want of combustible materials is everywhere
felt, it is important that none supplied by nature should be neglected, and that
all should be rendered suitable for the purposes of industry; peat, which is so
profusely spread over the surface of the earth, is in every respect worthy of
attention, both on account of the heat which it developes and the valuable
products which can be extracted from it. The object of this Invention is to
improve the quality of the fuel by a particular mode of preparation, and to
effect the extraction and manipulation of the hydro-carburets contained therein
by improved processes. The two chief defects of peat are, the presence of
extraneous mineral substances in its mixed state, and its want of homogenous-
The object and effect of a good mode of preparation should therefore be
to remedy these two defects. For this purpose I employ a moveable crusher
consisting of a hopper A (Sheet 1), in which the peat is deposited in the state
it is extracted by the spade or drag.
A cast-iron roller B, furnished with short strong teeth, which occupies the
bottom of the hopper, and in turning on its axis it commences to divide the peat.

page_text: Two other rollers C, D, similar to the first, are placed on a lower level;
these rollers turn in contrary directions and complete the crushing by means
of their teeth which take between each other. The peat torn and subdivided
by their action falls into a vat or case of sheet or cast iron, or other material
E, in which an agitator G, furnished with vertical pallets H, rotates on a
vertical shaft F. The vat E is contained in a deeper and larger one a, into
which a pump throws a continuous stream of water. The peat diluted to a
state of liquid mud and stirred by the agitator deposits the gravel and relatively
heavy substances which it contains at the bottom of vat E, while the pure
parts of the fuel being lighter are carried away by the excess of water which
overflows all round case E, and falls into case a, whence it leaves through
aperture b, which remains open during the whole operation. The gravel falls
to the bottom of vat E, and is removed from time to time through aperture c,
which is at other times closed. The cylinders and agitator are actuated by
hand by means of a crank handle, fly wheel, and toothed gear.
This process of crushing and cleansing united is very beneficial to the peat,
which becomes very homogeneous after it has been allowed to fall in drops and
become dried.
Peat prepared thus may be sent into the market, but as it possesses qualities
which allow of excellent fuel being made from it for metallurgical purposes,
the most suitable means for obtaining this product in good quality with
economy is desirable, collecting at the same time the hydro-carburets contained
in the peat without altering them, and in the greatest quantity possible. The
result of this study is, that carbonization should be effected in a closed vessel;
that the liquid products of distillation should be collected at the very outlet of
tho retorts to avoid obstructions and alterations of the hydro-carburets pro-
duced by long passages; and, lastly, that the gases should be collected under
the retorts to be burnt there.
The peat before carbonization is placed in a trough A (Sheet II.), in which
it is dried by the waste heat of the furnace, and if required, by the circulation
of the smoke. In order to carbonize it, it is introduced by covers o into cast-
iron retorts B placed obliquely, and furnished at their lower extremities with
closures o', for effecting the discharge or withdrawal of the fuel. The gas and
volatile matters escape through pipes d, g, h, and enter a vessel C, in which
the bydro-carburets and ammoniacal waters are deposited, which leave by the
pipen (furnished with a stop-cock) and pass into the receiver or refrigerator
E, which is closed by a lid having hydraulic joints. The gas on leaving the
vessel is conducted through pipe i, j, into a receiver D, dipping into another
which is somewhat larger, and forms a double case in which cold water

page_text: circulates. The purification of the gas is completed by the condensation of
the essential oils carried with it. These oils are extracted by a special tap,
while the gases escape through pipe k and enter either into gasometers or
directly into the furnace under the retorts. The furnace is furnished with
supplementary fire-bars F, which serve to burn solid fuel in case of insufficiency
of gas, chiefly at the commencement of the operation.
This economical process produces a very dense peat fuel or coal and allows
of collecting without any sensible loss hydro-eburets rich in essential oils.
These hydro-carburets must then be treated in order to separate them into
three principal classes, light oils, parafine oils, and resin. I propose to unite
all the operations in a single one, and employ but one furnace.
The tar having been obtained by the distillation above described is placed in
the tank A (Sheet III.), in which it is warmed by the waste heat of the
furnace, and if required, by the smoke. It goes thence into the boiler B,
which is heated by the smoke which has already circulated around the beator
or boiler G, berein-after referred to; the light oils, which are very volatile, pass
into the tube b, which has a double case 1, and a circulation of cold water, in
which they are in a great measure condensed, and thence into a receiver D,
also immersed in cold water, in which the condensation is completed. The gas
carries off what remains of the vapours and enters the chimney of the furnace
through the pipe f. The circulation of cold water is effected by a head of
water in the reservoir H, which is kept full by the action of a pump or
otherwise.
The less volatile matters which remain in the first boiler B are conducted
by the pipe and cock d into the lower boiler G, where they are subjected to
a more intense heat, which volatilizes the parafine oils, which by means of an
arrangement analogous to that described with reference to light oils, enter
the refrigerator E. What remains in the boiler C is resin, which is collected
in the vessel I by the discharge pipe E (furnished with a cock) for this
purpose.
In order to complete the series of operations, there only remains the puri-
fication of the oils to be described. This operation is effected by known
processes, to which much benefit can be added by
H good filtering.
In order to obtain this result with facility, I make a more or less perfect
vacuum under the filter, so that the atmospheric pressure being no longer
balanced drives the liquid through the filter. A filter covered with a thin
film or layer of liquid thus acquires as much force as if covered with a very
thick film or layer. This filtering, which I term atmospheric filtering, is
applicable to filters of all kinds, whether composed of pulverulent, filamentous,

page_text: spongy, or other substance; to be inore explicit, I will give an example of
one relating to a filter of sand laid in horizontal layers in a basin of brick-
work, or it may be wood or metal. The bottom of the basin is formed of a
hydraulic paving c (Sheet IV.) resting on an area of beaten clay c. The
enclosing walls 6 are also constructed of hydraulic brickwork, as also the
partitions b', which divide the basin into several compartments; a small
channel G is made in the direction of the axis of cach of these compartments.
On paving C, and perpendicular to the channel, small walls are arranged;
they are formed of two or three rows of bricks superposed. These walls are
one brick thick and are separted by spaces of the same width; the whole is
covered with a row of bricks without mortar a', arranged in a contrary
direction, which forms a second paving which is permeable at all its joints.
The filter, properly so called, rests on this paving, and the liquid whichi
traverses it enters easily into the empty spaces. A filter of sand or other
pulverulent matter should be formed of successive finer and finer layers, so
combined that the grains of no one of them can traverse the interstices of the
one immediately below. As the law securing these conditions has never been
heeded I will indicate it in such manner as has been established by calculations.
If three equal spheres of a radius R touch each other, and the radius of
the sphere which can just pass into the triangular space left between them,
being 2, it will be found by elementary geometry that the following equation

page_text: It suffices to form the first layers of about an inch in thickness to support
the fine layer, which should be from three to five inches in thickness. The
surface of cach of the three first layers is dressed with a rule which is made
to slide on steps or guides arranged for that purpose.
Each compartment receives the liquid through a special conduit and cock
or sluice door m; the liquid enters an anterior basin, whence it passes on to
the filter bed; this basin is useful at the commencement of the action. The
liquid, the flow of which is moderated, passes in very thin films and with but
little rapidity on to the sluice, which prevents it displacing the sand. Each
central channel communicates with a pipe f, which also has a cock or sluice
door, and is a branch on the general exhaust pipe H. These cocks or sluice
doors allow the isolating successively each compartment, in order to clean it
while the others are acting. The exhaust is effected by a machine, or by the
simple communication of the pipe with the basin placed on a lower level.