AN IMPROVED MEANS OR APPARATUS FOR COLLECTING AND DISCHARGING DUST AND LIGHT PARTICLES, WHILST PURIFYING MIDDLINGS OR LIKE GRANULAR SUBSTANCES
Year: 1884

page_text: I JACOB BELL HOLGATE of 1 Junction Street Burnley in the county of
Lancaster Miller, do hereby declare the nature of my said invention for "AN
IMPROVED MEANS OR APPARATUS FOR COLLECTING AND DISCHARGING DUST AND
LIGHT PARTICLES, WHILST PURIFYING MIDDLINGS OR LIKE GRANULAR SUBSTANCES
to be as follows:-
The object of this invention is to collect upon a travelling surface, dust and light
particles from air, after it has passed through middlings, or like granular substances,
and to discharge the dust and light particles, thus collected, by a reverse current of
air or back draft which passes through the travelling surface, by which means
beating, shaking, and stopping the surface for cleaning purposes may be dispensed
with, whereby greater durability of the surface is ensured, more middlings or like
granular substances purifyed and a considerable saving of labour effected.
I employ an endless webb of cloth or other suitable material, that will allow a
free passage of air through the webb, and at the same time, collect and retain, dust
and like particles, whilst purifying middlings or like granular substances. This
webb is mounted on two rollers, one at each end of the machine, one of these
rollers is adjustable to keep the webb properly stretched, the other roller may be
driven from any convenient moving part of the machine, and to relieve the webb
from strain and pull in passing over the rollers. I separately bind each edge of
webb, between two strips or bands of leather or other suitable material, two other
strips or bands are placed and secured along the center of the webb, The strips
or bands of leather are the only parts of the webb in contact with the rollers, so
that the dust receiving portion of the webb is prevented from pressing upon the
driving surface of the rollers, which would otherwise have a tendency to "Mill" or
fill up the pores of the cloth, and thereby interfere with the free passage of the air
to the exhaust. Suitable grooves are provided, one on each side of the racepticle,
to recieve the edges of the webb, bordered with leather, and thus form a com-
parative air tight passage for the webb along the sides of the recepticle, to prevent
the dust and light particles from passing into the exhaust. These grooves also

page_text: serve as supports for the webb, which is further supported by longitudinal strips
of wood, placed in the center of the recepticle. The endless webb, or travelling
surface passes through the recepticle, in which middlings or like granular sub-
stances are purifyed collects the dust and light particles, from the current of air
passing upwards through the webb to the exhaust. The ascending current of air
binds the dust and light particles against the webb whilst travelling through the
recepticle, the surface of the webb passing over an hopper at the end of the
machine, and is there acted upon by the reverse current of air, which drives
the dust and light particles from the webb down the hopper into a suitable dust
chamber.

page_text: COMPLETE SPECIFICATION.
I, JACOB BELL HOLGATE of 1, Junction Street Burnley, in the county of
Lancaster, Miller, do hereby declare the nature of my invention for AN IMPROVED
MEANS OR APPARATUS FOR COLLECTING AND DISCHARGING DUST AND LIGHT
PARTICLES WHILST PURIFYING MIDDLINGS OR LIKE GRANULAR SUBSTANCES," and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:―
This invention has reference to the construction of apparatus for collecting dust
and light particles suspended in air whilst purifying middlings, and to the discharge
of the dust or extraneous matter after its collection, without requiring on the part
of the attendant any assistance whatever, so that the purification of the material
under treatment may proceed uninterruptedly.
The apparatus is also generally applicable for purifying currents of air from dust
or other impurities suspended therein.
In mille for purifying middlings, it has been customary to fit up an appliance
usually termed the balloon, into which the dust laden air proceeding from the
middlings purifier, was conveyed and filtered by passing it through canvas,
encircling the apparatus before its exit into the room. This method served the
purpose, so long as the dust receiving portion was clean and unimpeded by
accumulations of dust, after which the exhaust was shut off, and the parts com-
posing the apparatus cleansed; during which time, dust and like impurities were
carried along with the middlings, with which they were discharged from the
purifier, rendering the process incomplete. Stive rooms and similar dust collecting
chambers, introduced from time to time had the same and other attendant evils to
the one previously described.
In carrying out my invention, I employ an endless webb of flannel, canvas, or
other suitable material mounted on adjustable rollers, their axes resting in and
passing through suitable bearings, adapted to the frame of the apparatus. Upon
these rollers the webb is kept properly stretched, and to releive it from strain and
pull in passing over the surfaces of the rollers, I bind the edges and centre of the
webb between strips or bands of leather or other suitable material of sufficient
thickness to hold the dust receiving portion of the webb out of contact with the
driving surfaces of the rollers, which would otherwise have a tendancy to "mill"
or fill up the pores of the travelling filtering webb, and thereby interfere with the
free passage of air to the exhaust fan. Suitable grooves are provided on each side
of the purifier to receive the leather bordered edges of the webb, and to prevent
dust and light particles from passing into the exhaust. These grooves also serve
as supports for the webb, which is further supported by longitudinal strips of
wood, between which the bands of leather are sustained in the middle of the webb,
which is thereby prevented from bagging.
The webb or filter cloth in travelling gradually brings its dust laden surface
over an hopper, where it is acted upon by a reverse current of air or back draft,
which drives off dust or extraneous matter adhering to the collecting surface of the

page_text: webb down into a suitable dust chamber, from whence it is conveyed away by an
Archimedean screw.
To assist in the collection of the heavier particles of dust carried upwards by
the exhauster, I employ a suitable number of V shaped troughs secured in a
suitable position to be clear of the middlings under treatment. Into these troughs
the heavier particles of dust incapable of reaching the travelling surface of the
webb fall, from whence they are conveyed along suitable channels to the Archimedean
screw above alluded to.
And in order that my invention may be fully understood and readily carried
into effect, I have hereunto attached the accompanying sheets of drawings;
reference being had to the figures and letters marked thereon.
Fig 1, sheet 1, is a longitudinal sectional elevation of a Middlings Purifier, with
my improved apparatus for collecting and discharging dust and light particles,
applied.
A, is the frame of the apparatus; B, the hopper through which middlings are
evenly fed upon the screen or sieve C, over which they are caused to travel
forward by a vibratory movement imparted to the sieve or screen, which being
composed of various sections of different degrees of fineness, sifts and urges the
middlings below.
In the upper portion of the purifier are arranged several compartments divided
by partitions D, and are provided at the top with valves or flaps so arranged that
the currents of air drawn through the meshes of the different sections of the screen
or sieve by the exhaust fan E, may be regulated or modified. The meshes of the
first section at the feed end of the purifier are the finest and require the weakest
current of air; the valve or flap in the compartment above being adjusted to
modify the current so as not to raise the middlings capable of passing through the
meshes of this portion of the sieve. The constant vibratory movement of the
Bieve together with the gentle current of air gradually brings the lighter particles
of dust and husky matter to the top, and at the same time urges the finer grade of
the middlings under treatment through the meshes of the first section of the sieve.
The material is now urged forward on to the next section, through the meshes of
which the next larger grade of the middling falls. The valve at the top of the
compartment above this section being opened so as to allow the exhaust to act a
little more freely, gradually increasing the force of the currents of air ascending
through each succeeding section of the sieve.
During the foregoing operation, the dust laden air ascending from the various
sections of the sieve is filtered or strained before passing to the exhaust fan by the
webb or apron F, which being caused to travel through the purifier in an horizontal
direction by the rollers G, G³, and G³, is gradually brought heavily laden with dust
and light particles to the dust chamber H. In this chamber, the webb or apron is
automatically and thoroughly cleansed by currents of air which pass down pipe I,
from the exit port of the fan on to the reverse surface of the webb to that on which
dust and light particles were previously distributed, which are now discharged
upon the screw or worm J.
At the foot or delivery end of the sieve or screen, a number of troughs or
pockets N are placed side by side with spaces between them, and secured by their
ends to side pieces of the same depth, which are bent so as to form a longitudinal
channel M on each side of the troughs or pockets, from each of which apertures
proceed, terminating into the longitudinal channels. These troughs are preferably
V shaped, so as to present the least possible impediment to the ascending currents
of air, which are temporally compressed whilst passing the said troughs, after
which they expand over the troughs or pockets, into which the heavier particles
incapable of reaching the travelling surface of the webb gradually settle. The
troughs or pockets extend from side to side, and are placed as near as convenient
to the surface of the sieve, with which they are perfectly level, so that the troughs
or pockets may receive as heavy particles of dust at one part thereof as at
another,

page_text: Fig. 2 is a sectional side view of the troughs, in which view is seen an inner
lining or false bottom inclining from the centre to each end, so as to cause the
particles deposited thereon, to gravitate each way in the direction of the channels M,
into which they enter through apertures seen in end view Fig. 3. A vibratory
motion may be imparted to the troughs or pockets to facilitate the gravitation of
the particles deposited thereon, impelling them forward to the worm seen in Fig. 1.
I will now describe more fully the construction of the webb, and the means
I employ for its protection and support, and for preventing the escape of dust and
light particles at the sides of the apparatus to the exhaust. As seen in Figs. 4
and 5 the edges and centre of the webb are bound between bands or strips L of
leather or other suitable material, of sufficient thickness to prevent the webb from
coming in contact with the driving surfaces of the rollers, which would otherwise
have a tendancy to "mill" or fill up the pores of the filtering webb. These bands
also receive the tractional strain imparted by the rollers, whereby, the webb C may
be constructed of any light porous material such as flannel, which I prefer as its
long projecting fibres are better able to retain upon its surface dust and light
particles.
.
The bordered edges of the webb C travel in grooves S, the ends of which abut
against a semicircular rim or flange fixed to each side of the apparatus, and made
to project a little beyond the periphery of the roller G. Near each edge of this
roller, a flexible band O is attached to a crosspiece T, and weighted by the weight U
(seen in Fig 1) so as to gently embrace the bordered edges of the webb and the
stationary rim, whereby the escape of dust and light particles at the sides of
the apparatus to the exhaust is prevented, and the air allowed to escape to the
atmosphere in a pure state.
In Fig 5, is seen rods P, which support the the centre of the webb C to relieve it
from unnecessary strain at the sides. Figs 6, sheet 2, is a sectional elevation
representing a modification of my improved apparatus.
a, is the framework closed in with canvas; b, the rollers which impart a
travelling movement to filter cloth c, which is so fixed to a number of light skeleton
frames gas to form a succession or series of troughs and ridges as seen in Figs 6
and 7, whereby the length of the filter cloth is considerably increased, enabling me
to construct an apparatus of considerable less dimensions to those now in use, and
one more easily and readily adapted to existing purifiers or separators.
The skeleton frames above alluded to, are secured to endless bands d with
intervening layers of india-rubber webb or tubing o, and mounted on rollers b.
The dust-laden air as it proceeds from the exhaust fan of a purifier or other
separator used in corn mills (to which my invention more particulary relates) may
be conveyed along pipe e into the collecting apparatus, and there distributed over
the filter or straining cloth c, which is made to gradually and slowly reach the
chamber p, above which is situated a pair of bellows k, the folds of which are
opened and closed intermittently by a suitably formed cam, to actuate the
quadrant hand rack spindle f, so as to cause a sudden gust or blast of air upon
the inner surface of the filter cloth c, at distant intervals of time, that is to say,
that a length of filter cloth almost equal to the width of chamber p, may be
allowed to pass before the blast is again applied to the next length of filter cloth
presented, from the outer surface of which dust and light particles are discharged.
By the application of the sudden blast above alluded to, dust will be discharged
from the filter cloth more effectually, and a considerably less quantity of air will
be infused into the chamber p, so as not to interfere with the free action of the
exhaust.
The partitions m are each provided with a valve or flap n, which excludes the
air proceeding from the exhaust fan from passing into this chamber, but is capable
of yielding to the dust which continually falls from the filter cloth, and which
accumulating opens the valve and escapes to the worm.

page_text: Having now particularly described the nature of my said invention, and in what
manner the same is to be performed, I declare that what I claim is
Firstly, the endless filter cloth with bordered edges and attachments, substantially
as described for the purposes specified.
Secondly, the combination of V shaped troughs with the filter cloth, as described
and set forth.
Thirdly, the application of a reverse current of air or back draft, as described for
the purpose specified.
Fourthly, the application of a blast of air acting after the manner described in
reference to Fig. 6.
Fifthly, the mode or manner of increasing the surface of the endless filter cloth,
substantially as described in reference to Figs 6 and 7.