The Production or Recovery of Coal Dust for Foundry Purposes, and the Machinery or Apparatus Employed therefor.
Year: 1894

page_text: Date of Application, 26th Nov., 1894-Accepted, 12th Jan., 1895
COMPLETE SPECIFICATION.
The Production or Recovery of Coal Dust for Foundry Purposes,
and the Machinery or Apparatus Employed therefor.
I, DONALD YOUNG, of Balgray Cottage, Springburn, Glasgow, in the County
of Lanark, North Britain, Millwright, 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:-
This invention relates to the production or recovery of coal dust for foundry
purposes, and to the machinery or apparatus employed therefor, and has for its
object to recover coal dust from coal washings and pond settlings, the said coal
dust being used by iron founders to mix in the sand to give a skin to the casting, as
is well known.
In carrying out my invention I take the coal washings, though preferably
the pond settlings, and I dry them in a suitable drier after which I pulverize, mix
and cool them by means of crushing rolls from which they pass through a graded
sifter in such a manner as to produce various qualities of coal dust for foundry
purposes.
The machinery or apparatus I employ is as shown in the accompanying drawings.
Figure 1 is an elevation,
Figure 2 is a plan.
Figure 3 is a cross section on line X. X. Figures 1 and 2. And
Figure 4 is an end elevation.
Referring to the said drawings I employ a drier preferably composed of a hollow
sheet metal cylinder A having a central shalt a and bearings a¹; the said
cylinder A is mounted above one or more furnaces B, within a suit ible heat chamber C.
in such a manner, that on the material being fed into the cylinder A through the
shoot a, and the cylinder A revolved, by means of spur or other gearing D from
any convenient motor, the material will pass down through the said cvlinder A and
out through the shoot a³, in a dried condition into a well or chamber E.
In order to ensure of the material being agitated and broken up or mixed during
the drying process, I provide the said cylinder A with a number of angle iron or
other internal ribs a' which run lengthwise, also if desired, I may provide the
cylinder A with a sheet iron or other divisional plate a', so as to the more
effectually agitate the material during its passage through the drier, or in lieu of
said plate a, I may employ a series of graded seives or partitions.
After the material has been dried and passed into the well or chamber E, it is
conveyed up and on to a seive F, by means of a bucket and band or other
suitable conveyor G, through which the fine material passes while the lumps or
pieces of coal pass down the shoot f, on to the floor from which they may be
recovered and used for any convenient purpose, such as for heating the chamber C
by being burned in the furnaces B. The fine material after passing through the
seive F is ground, cooled and mixed, by means of a crusher consisting of a pair of
granite or other rollers H, the one of which is suitably driven while the other is
driven by friction, there being suitable means, such as movable bearings and
screws h, provided for enabling the roilers H to be kept in contact with each other
or otherwise adjusted. The inaterial after passing through the rollers H passes
down a suitably shaped shoot into a well or chamber K from which it is
convey ed up and into another shoot. L. by means of a suitable conveyor M. as
shown.

page_text: The material after reaching the shoot L passes into a pentagonal or otherwise
shaped revolving seive N having one, two or more grades of meshed wire covering,
though preferably three grades, as shown, so as to produce three different qualities
of coal dust, there being a trough N¹ having a worm or other conveyor N'; said
trough N¹ having an outlet opening or shoot P provided for each grade of dust; said
outlets P being provided with shutters p so as to enable the coal dust being
bagged or otherwise packed for use.
In the event of any material being passed into the seive N which is too coarse to
pass through either the fine mesh 1, medium mesh 2, or coarse mesh 3, I leave the
end of the said seive open so as to permit of such coarse material passing out and
down a shoot Q into a worm or other conveyor R which returns it back into the
well or chamber E where it mixes with the newly dried material and is passed
through the rollers and seive again so that there is practically no waste of
material.
The whole of the foregoing apparatus or plant may be driven by any suitable
means from any convenient motor, and if desired suitable doors or openings may
be provided for inspecting the material at various stages of the process.
As a modification the drier may be a stationary cylinder having a revolving
screw or worm arrangement working inside it ; or may be a revolving kiln having
a stationary scraper mounted within it, and the crusher may be a pan mill or other
grinder.
Also as a further modification, I may if desired, dispense with the use of the
crushing, cooling and mixing rolls, and their seive and elevator, in which case the
dried material would be conveyed direct to the seive and the coarse material
burned or otherwise used.
The whole of the foregoing thus forms an efficient apparatus or plant by the use
of which coal washings, pond settlings and the waste from waste bins may be
converted into various qualities or grades of coal dust for foundry purposes.
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 :-
1st. The production or recovery of coal dust for foundry purposes from coal
washings or pond settlings, substantially in the manner as hereinbefore described.
2nd. In the process of recovering cal dust, the apparatus consisting of a
revolving drier, a crusher, cooler and mixer, and a graded revolving seive and
their connection, substantially as herein before described and shown in the
accompanying drawings.
3rd. In the process of recovering coal dust, the modified apparatus consisting of
a revolving drier and a graded revolving seive and their connections, substantially
as hereinbefore described.
Dated this 23rd day of November 1894.
JOHNSONS,
115, St. Vincent Street, Glasgow, Applicant's Agents.