IMPROVEMENTS IN THE MANUFACTURE OF COMPRESSED FUEL
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, WILLIAM ADGIE, of 68 St. Marks Street, Leeds, in the County of York,
Accountant, do hereby declare the nature of my invention for IMPROVEMENTS
IN THE MANUFACTURE OF COMPRESSED FUEL to be as follows:-
My invention relates to the forcing of heated air through small coal and pitch
(or other materials) whilst passing through a suitably contrived pugmill or other
similar apparatus.
The object of my invention being (after rendering the materials sufficiently plastic
to compress into moulds) the leaving of the materials in a drier state and in an
improved condition for moulding.
In carrying out my invention I proceed as follows-With any ordinary air,
compresser I force air, in suitable quantities, through an ordinary air heating
furnace in which it is raised to the heat found most effectual for the quantity and
quality of the material to be operated upon. I then conduct this heated air into a
specially fitted up pugmill, or other heating box, in which it is intermixed with the
small coal and pitch (or other materials) In passing through this pugmill or box
the materials are rendered plastic, by the heated air, and ready for compression,
whilst the superfluous moisture is carried off when the air is liberated-The fuel
may be compressed into blocks in the ordinary way-The Pugmill I fit up in the
following way I take any suitable pugmill, whether vertical, horizontal, or
diagonal, and insert a number of inlet pipes, through which the heated air is forced,
placing them in such numbers and positions as shall best distributo and force the
air through the coal and pitch whilst the materials are kept in motion by the
revolving knives of the pugmill-If found convenient the outlet for the air may be
arranged with a valve for the better regulation of the discharge of the spent air-
The pugmill may be made with or without a heating jacket, and the passage of the
coal & pitch (or other materials) through the mill may bo continuous or inter-
mittent preferably the former.
JASPER & W
SNOWDON,
Agents for the Applicant,
Beckett's Bank Chambers,
Leeds, Yorkshire.

page_text: I, WILLIAM ADGIE, of 68 St. Marks Street, Leeds, in the county of York,
Accountant; do hereby declare the nature of my invention for IMPROVEMENTS
IN THE MANUFACTURE OF COMPRESSED FUEL; 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 the forcing of heated air through small coal & pitch (or
other materials afterwards to be understood when conl & pitch are mentioned)
through a suitably contrived pugmill or other similar apparatus.
The object of my invention (after rendering the materials sufficiently plastic to
compress into moulds) is to leave the materials in a dryer state & in an improved
condition for moulding, & further to reduce to a minimum the quantity of pitch
required. It is self evident that heated air (and by heated air I mean air not only
heated before entering the materials in the pugmill, but air kept hot during its
passage through the materials) will tend to soften or melt the pitch & at the same
time absorb any moisture left in the coal or its equivalent. In the latter quality it
differs from steam as ordinarily used.
In carrying out my invention I proceed as follows:-With any ordinary air
compresser I force air in suitable quantities through an ordinary air-heating furnace
in which it is raised to the heat found most effectual for the quantity & quality of
material to be operated upon. I then conduct this heated air into a specially fitted
up pugmill or other heating box in which it is intermixed with the small coal &
pitch. In passing through this pugmill or heating box the materials are rendered
plastic, by the heated air, and ready for compression, whilst the superfluous moisture
is driven off when the air is liberated.
This reference to forcing heated air must not be taken to infer that I attach any
value to air under pressure, as I only use such pressure as may be found necessary
to force the hot air through and amongst the materials. The pressure will vary
according to the size and character of the pugmill & the amount of material passed
through it. In a general way, in a horizontal pugmill such as shewn in the
accompanying drawing, a pressure of 4 lbs. to 10 lbs. per square inch will be found
sufficient; but in a vertical pugmill a much greater pressure will be necessary-due
to the height of the materials-Practice will shew at once what is required.
Having specified the amount, as near as possible, of force, or pressure per square
inch, necessary to press the air through the material, I would have it understood
that the quantity of air passed through, & also the temperaturo to which the air
must be raised, depends entirely upon the class of coal & pitch to be operated upon,
For instance, if coal or other such
& upon the general condition of the snine.
material be wet or damp, a greater quantity of heated (and consequently dry) air
should be passed through, and this regardless of the temperature of the said air.
And again, different classes of coal require different temperatures, or rather, will
permit a greater or less temperature to be used without driving off any practical
aimount of valuable volatile matter from either the pitch or coal, which must of
course be avoided.
-
The pugmill I fit up in the following manner-1 take any suitable pugmill K,
which may be horizontal, vertical, or diagonal; this is shewn horizontal on the

page_text: accompanying drawing which is laid out to a scale of 1 inches to the foot, on
which fig. I is an elevation, partly in section; fig. 2. an end view, partly in section,
whilst fig. 3 is a plan, also partly in section. The same letters refer to the same
parts in all the figs. I fit this pugmill with an outer jacket or casing L, which
5 jacket can be made to go all round, or only part of the way round, the pugmill; the
heated air is conducted through the jacket, at any point C, into the space between
the jacket and the pugmill, by which means the shell of the pugmill becomes heated;
by means of any number of suitable inlets D, D, the heated air passes into the
interior of the pugmill, coming in contact with the coal & pitch which is fed into
the hopper E and gradually carried forward by the revolving shaft F and knifes G
to the outlet at the end II, by which time it has become ready for moulding and
compressing. The fuel may be compressed into blocks in the ordinary way. The
outlet for the air can be arranged, when working horizontally, at any of the
outlets I, I, & can be fitted with valves to regulate the same, placed in suitable
funnels for carrying off the hot & foul air. These funnels may be six inches square
or thereabouts. It will be seen that the coal & pitch becomes heated both by tho
heated air passing into the pugmill, and also by contact with the heated shell of the
pugmill. The heated air is also prevented from cooling by reason of this jacket.
The inlets D, D, are protected by covers or guards to prevent them being choked up
with the materials. The action of the pugmill may be continuous, or inter-
mittant, preferably the former.
Bituminous coal gives the best results under hot air; after this, semi-bituminous;
and lastly, anthrcite. This latter does not shew any great difference as between hot
air & steam. The quantity of air, at say 400 degrees Fah., I use is about 20 cubic
feet per minute in heating 14 cwt. of materials. The heat I use varies from 250
to 500 degrees Fah. This latter must seldom or never be exceeded, as a higher
temperature is liable to drive off the pitch in the form of. gas. The average heat
is about 400 degrees Fah.
With regard to proportions, between the amounts of coal & pitch, it may be
mentioned that one advantage in the hot air systein is that the amount of pitch is
reduced to a minimum. No practical man uses more pitch than is necessary, so
that a short trial with a different class of coal soon determines how little pitch can
be done with; the more bituminous the coal the less the pitch required.
I would further point out that, as already stated, the heated air must be kept hot
during its passage through the pugmill; if this bo not done then a proportion of
the moisture, absorbed & held in suspension, would be deposited again in the
materials last in contact with the cooling air, & hence I use a heating jacket round
the pugmill, or a heating box or some equivalent. The heating jacket may be made
as described on the drawing, or gas may be laid on & burnt under the pugmill, or
flames or hot gases made to encircle the same; but I prefer the jacket, which I
describe, as. being less likely to injure the materials. The air may be passed into
the jacket hotter than it would otherwise be supposing it had to pass direct into
the materials. The size of the inlets D, D, are ³/, of an inch in diainster, but these
may be varied.
9
Having shewn a drawing of a suitably contrived pugmill I wish it to be
understood that I do not confine myself to it alone as many modifications can be
arranged.
Having now particularly described & ascertained the nature of my said.
nvention, & in what manner the same is to be performed, I declare that what
claim is:-
=
1. The use of heated air applied substantially in the manner specified in order to
ry & render plastic materials for making compressed fuel.
2. The use of a specially fitted up pugmill, having heated air entering & leaving
he heating jacket, & then perimenting the materials in the pugmill, substantially
s described, in combination with a plant, consisting of compresser, air-heating
urnace, & pugmill, for making compressed fuel.

page_text: 3. The use of hot air applied substantially as and in the manner described in
order to reduce the quantity of pitch as far as possible to a minimum in the manu-
facture of compressed fuel.
4. The use of heated air applied in the manner specified in order to deal with
materials too wet to be dealt with in the ordinary way by suporheated steain.
Dated this eighteenth day of December 1884.