Improvements in Concentrating Machines for Ores and other Materials.
Year: 1895

page_text: Date of Application, 22nd Feb., 1895-Accepted, 30th Mar., 1895
Improvements in Concentrating Machines for Ores and other
Materials.
A communication from abroad by THE FRUE VANNING MACHINE COMPANY, of
Detroit, in the State of Michigan, United States of America, Manufacturers.
I, PHILIP MIDDLETON JUSTICE of 55 and 56 Chancery Lane in the County
of Middlesex, Fellow of the Chartered Institute of Patent Agents, 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 that class of concentrator which is commonly known as
a dry concentrator and which is formed with a perforated bed or screen over which
the ore or material to be concentrated is caused to pass, and during such passage is
subjected to the action of gusts of air rising through the screen from vibrating
bellows placed beneath.
According to this invention it is proposed to secure the desired result by the
automatic intermittent feed of compressed air from a reservoir or like source of
supply, and in order that the invention may be clearly understood reference is made
to the accompanying drawings in which:
-
Fig. 1 is general view of a plant consisting of an air compressing pump, a
reservoir and three concentrators.
Fig. 2 is an enlarged sectional elevation of Fig. 1 on the line =-2.
Fig. 3 is a sectional elevation of Fig. 2 on the line w―w.
Figs. 4 to 7 represent forms of valves adapted for automatic intermittent
air feed.
The chamber 1 is provided at the top with a perforated screen or sieve 2 resting
on transverse slats 3. On the screen is placed a usual bedding 4 of shot or
concentrated mineral or other suitable preparation. The crushed and sized ore in
a dry condition is fed on to the bed through the hopper 5 at one end of the same.
At a suitable point in the chamber the blast pipe 6 is introduced, and this may be
protected at its outlet by screen 7 to prevent any material falling from the screen 2
entering the pipe.
In front of the pipe may be arranged baffle plates if desired to effect a more
uniform distribution of the air over the under side of the ore bed. The blast pipe
is supplied with a valve 8 operated by spindle 9 which is kept normally closed by
the action of spring 10 under adjustable tappet 11. At the upper end of the spindle
is a second adjustable tappet 12 which is operated on by tappet or cam wheel 13
driven by conical pulley 14.
By pump 15 air is forced into receiver 16, and from the receiver a main air
pipe 17 conveys the air to the various machines as shown in Fig. 1, and each
machine is susceptible of the necessary independent regulation of its working as to
speed and air delivery necessary for working different grades of material, and with
the arrangement of parts indicated in Fig. 2. A rapid intermittent blast is
discharged from the pipe 6 by the action of the cam or tappet wheel 13 on the
valve spindle 9. The extent of the valve opening can be regulated by the
adjustable tappet 12, and the quickness of the closing motion can be regulated
by the tension of the spring 10 produced by the adjustable screw tappet 11.

page_text: •
The rapidity of the intermittent blast can be regulated by the form and number
of cams or tappets, or by the speed of the shaft controlled by the conical
pulley 14.
The exact form of valve used to produce the intermittent blast is not necessarily
limited to the form just described, as the same effect may be produced by a gate at
the end of the blast pipe held in place by a spring 20, and operated by a cam or
tappet as shown in Fig. 4. In this case a bent lever 18 may be used as shown, and
its movement outside the chamber provided for by an elastic covering 19 attached
to the lever; or the operating cam can be within the chamber 1 on a shaft which
extends through stuffing boxes in the sides of same. The valve spindle 9 can if
preferred be operated equally by direct connection with crank or eccentric from
the driving shaft, or by eccentric gear or other suitable device to produce varying
degrees of proportion between the time of opening and closing of the valve.
Figs. 5, 6 and 7 show a special form of revolving gate or valve. The valve 21
is a bollow cylinder fitting closely within valve body 22 on the blast pipe 6. The
valve spindle 9 is in this case hollow at its lower end to receive an inner spindle 23
attached to a second valve 24 fitted within the outer valve 21 and provided with
similar opposite openings. The inner spindle 23 is fitted with a short screw 25
projecting through a slot partly around spindle 9 in order that the two valves may
be set in any desired relation to each other. By partially revolving inner
spindle 23 with reference to spindle 9 the opening through the valve 21 can be
partially or wholly closed, and thus the quantity of air admitted to the
concentrator at each half revolution of spindle 9 can be regulated. An oil
hole 26 can be utilized for lubrication of revolving valve which is driven by
suitable gearing.
The improvement described admits of a simple and economical arrangement of a
number of different concentrators which are usually employed in concentration
mills for treating large quantities or different sizes of product on suitably adjusted
machines, as by this arrangement the different concentrators, although all
supplied from the same air reservoir, may be fitted with different valves or
differently set valves, and thus be adapted for treating materials of different sizes
or specific gravities.
The effect of the intermittent air jets or blasts produced by the mechanism above
described is to produce a pulsating movement in the bed of material 27 to be treated
in such a manner that the heavier particles will sift down through the bed and either
mingle with the prepared bed 4 or pass through the same and the openings in the
screen 2 into the chamber 1 where they can be eventually collected from suitably
closed discharge opening 28. In operating the machine it is on some material an
advantage to give a horizontal or vertical shaking motion to the screen 2 which
assists in the freeing and separation of the heavier particles in connection with the
pulsation produced by the blasts of air.
The movement of the lighter or waste particles towards the discharge end is
facilitated by placing the screen or ore bed on an incline from the feed hopper 5,
in which case several transverse wedge shaped cleats may be placed across the bed
to prevent too great difference in the thickness of the bedding 4.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me from abroad by my foreign correspondents, I declare that what I claim is :-
1. In a dry concentrating or separating machine the use of compressed air
admitted under the screen or ore bed by a series of automatically regulated
intermittent jets or blasts, substantially as described.
2. In a dry concentrating or separating machine the combination with a fixed or
shaking screen or ore bed of the intermittent air jets supplied from a reservoir of
compressed air, substantially as described.
.
3. In a concentrating or separating machine the combination of a cam or tappet
wheel operating spindle valve or other equivalent device in combination with an air

page_text: pipe and a closed chamber carrying a superposed layer of material to be treated,
substantially as set forth.
4. In a dry concentrator or separator the use of a revolving or reciprocating valve
so arranged that the opening through the same can be regulated in size, substantially
as and for the purpose set forth.
5. The combination and arrangement of apparatus whereby one or many
concentrators are arranged for receiving and utilizing automatically regulated
intermittent gusts of air for separating materials of different sizes or specific gravity,
substantially as set forth.
6. The combination of two or more concentrators arranged to receive intermittent
gusts from a central or common reservoir or compressor, substantially as and for the
purposes set forth.
Dated the 22nd day of February 1895.
PHILIP M. JUSTICE.