Charged with Stive or other Light Particles.
Year: 1886

page_text: Charged with Stive or other Light Particles.
We, WILLIAM COMERFORD and JAMES COMERFORD, trading as "James Comer-
ford & Sons," at Rathdrum Mills,, Rathdrum, in, the County of Wicklow, Ireland,
Millers, do hereby declare the nature of this Invention to be as follows:-
This Invention relates to improvements in dust-catchers or apparatus for filtering
air, and preventing waste in mills, factories, or places where the air current or the
atmosphere is charged with stive, dust, or light particles, such as in mills for
grinding purifying, or dressing, corn and middlings, bones, gypsum, drugs, chemicals,
and other substances which when diffused in the air are injurious to health, or
are otherwise prejudicial, and the Invention consists in the employment, as an air
filter, of granular materials, and, in the case of flour mills, the small wheat which is
separated out from good wheat in the preliminary process of wheat cleaning; the
said granular materials, or wheat, being packed in the form of a layer, or layers,
between perforated reticulated, louvred, or otherwise apertured, walls or surfaces
which give passage to the air without permitting the escape of the filtering
material. The filtering material would be cleaned of the intercepted stive, or
dust, in a rotary or other sifting machine without the introduction of an air-blast,
and this may be performed automatically or not; and either intermittently, or
continuously, and simultaneously with the air filtering operation. In the latter
case, the apparatus would be so arranged that a continuous circulation of the air
filtering medium would be maintained the said material travelling through the
apparatus and being continuously passed into the cleaning apparatus, and returned
to the filter after being cleaned. In this case, two separate, but adjacent, layers of
the filtering medium would, preferably be employed, and their progress towards
the cleaning machine would be intermittent and alternate.

page_text: Charged with Stive or other Light Particles.
We WILLIAM COMERFORD and JAMES COMERFORD (trading as James Comer-
ford & Sons at Rathdrum Mills Rathdrum in the County of Wicklow Ireland
Millers, 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 improvements in dust catchers or apparatus for filtering
air, and preventing waste in mills, factories, or places where the air current or
the atmosphere is charged with stive, dust, or other light particles, as in mills for
cleaning, grinding, purifying, or dressing corn and middlings, grinding bones,
gypsum, drugs, pigments, chemicals, and other substances which when diffused in
the air are injurious to health or are otherwise prejudicial, or which are sufficiently
valuable to make the dust worth recovering. And the Invention consists essentially
in the employment, as an air filter, of beds or layers of what we term granular
material, the nature of the material used depending on circumstances, and varying
for instance according to the nature of the dust, stive or light particles to be
caught, and according as it is desired to save it, or merely to intercept it because it
is injurious to health.
Generally speaking when it is desired to recover the stive, dust, or light particles
the granular filtering medium would be of a nature analogous to the nature of the
dust or stive, etc, to be intercepted and might consist of the same material in its
unground or coarsely ground form so that when the filtering medium charged with
dust or stive is ground, the latter will be recovered along with the ground product.
Thus, in the case of flour mills, the small wheat which is separated out from good
wheat in the preliminary process of wheat cleaning, or crushed corn or bran, may
be used, but small wheat is eminently suited for the purpose in the case of flour
mills, the stive or dust being caught by the beard of the wheat and being either
recovered in the product of grinding this wheat or it may be separated by cleaning
the wheat as hereinafter mentioned. When the stive or dust etc, is practically
valueless saw dust may be used as the filtering medium.
In any case the so-called granular filtering material is used in the form of beds
or layers and is generally packed between, or otherwise supported by perforated,
reticulated, louvred or otherwise apertured walls or surfaces which give passage to
the air whilst retaining the filtering material or permitting it to escape only in
small quantities.
The apparatus is preferably so arranged that an intermittent circulation of the
air filtering medium may be maintained through it in order that the filtering
medium may be frequently renewed, the material as it becomes charged with stive
or dust being removed to be cleaned or otherwise treated. The passage of the air
through the filter may also be intermittent, so that no air shall be allowed to pass
through the filtering medium whilst the latter is in motion as this, if permitted,
might with some materials cause the disengagement of the dust etc, already caught.

page_text: To render the operation continuous, two separate filters might be used alternately,
the air current being switched from the one to the other by suitable means.
When the intercepted stive or dust is a valuable product, the filtering material
removed from the filter may be cleaned in a rotary or other sifting machine, without
the introduction of an air blast.
Reference is to be had to the accompanying drawings forming part of this specifi-
cation wherein Figure 1 represents a longitudinal elevation; figure 2 an end elevation
and figure 3 a cross section of one form of apparatus embodying the Invention of a
granular dust catcher or air filter. Figure is an elevation and figure 5 a plan or
horizontal section illustrating the arrangement of the dust-catcher when worked
by exhaust. Figure 6 is a longitudinal section, figure 7 a cross-section, and figure 8.
a plan, of another form of apparatus in which the filtering material occupies a
horizontal instead of a vertical position. Figure 9 is a side elevation shewing the
driving gear. The same letters of reference indicate the same parts, or parts
fulfilling the same purpose, in all the figures..
The apparatus shewn in figures 1 to 5 consists of a long narrow closed chest or
chamber, the sides of which are formed by double walls a preferably of perforated
sheet metal or wire cloth between which is packed the granular filtering medium
which is supplied thereto through the space between the double roof of the chest
preferably by a screw conveyor b extending along the top of the chest às shewn,
to ensure a uniform distribution of the filtering medium which descends by gravity
between the double walls a. The apparatus is provided with means of withdrawing
the filtering medium preferably rollers c which close the bottom of the space
between the double walls a. These rollers may be slightly fluted and may be
rèvolved intermittently as hereafter described, and deliver the portion of the
filtering medium withdrawn into the hopper shaped bottom of the chest whence it
is withdrawn by a screw conveyor d. e is the inlet trunk for the dust-laden air to
be purified. This may either be forced in by the fans in connection with the trunk
and with the various machines from which the dust comes, or if one large fan is
used for the whole mill, the air filter would be worked by exhaustion as described
in reference to figures 4 and 5. Continuous rotary motion is imparted to the screw
conveyors, and intermittent rotary motion may be imparted to the rollers c by any
suitable mechanical device, preferably by a double endless chain frunning on
sprocket wheels g g on the shaft of conveyor b and sprocket wheels h h on a
spindle, the two chains being connected by a cross link i, one or more of which
engages an arm k fixed on the spindle between the wheels h and turns. the same a
partial revolution each time the cross-link travels around the wheels h. The two
rollers c may be driven from the spindle by an endless chain 1 and pair of spur
wheels.
In order that the filtering material may be shifted and partially withdrawn
without the air passing through it whilst it is in motion, and in order to prevent
any interruption in the air filtering operation we would prefer to provide duplicate
air filtering or dust catching apparatus; the dust laden air being switched from one
to the other by means of an air valve which may be operated by the chains f, so
that whilst the filtering material is being shifted and removed from the one
apparatus the dust-laden air would be directed into the other apparatus, and con-
versely. The dust-laden air is forced into the apparatus illustrated in figures 12
and 3 by the fans in connection with the grinding or other machinery in which the
air becomes laden with dust. The trunk e of the apparatus shewn in figures 4 and 5
is in direct connection with the said machinery, and the dust laden air is drawn
through the filter by an exhaust fan, the filter being enclosed in an air tight
casing t in communication with the inlet of the fan, as shewn.
In figures 6, 7, and 8 the bed of filtering material A occupies a horizontal position
being supported upon an endless creeper a of wire cloth running round rollers B C
and prevented from sagging by resting on a grating D over which it is caused to
slowly travel. The bed of filtering material would generally be enclosed above by
a casing or chamber E to which the dust laden air is drawn of forced in through

page_text: the inlet trunk e the air passing down through the filtering bed which arrests the
stive, dust, or light particles, the purified air passing through the creeper and
grating to the space F beneath. The space F is boxed in, and communicates with
a flue G leading to the exhaust fan, or into the atmosphere as the case may be.
The filtering material is deposited on the creeper from a hopper B immediately
above it at one end, the depth of the bed being gauged and rendered uniform by
an adjustable striking plate I.
Slow intermittent or continuous motion in the direction indicated, is imparted
to the creeper by suitable mechanism, and the filter bed passes at the tail end of
the creeper under a throat plate K which may be pivoted so as to rest on the bed
with just sufficient pressure to prevent the escape of the foul air at that point, the
foul material being received from the creeper in a spout L leading into a closed
receptacle or directly into a sifting machine by which it is cleaned for use again.
The mechanism shewn in figures 8 and 9 for moving the creeper (say at the rate
of one inch per minute more or less as circumstances may require,) may be some-
what similar to that before described, i.e. by a pair of endless chains f receiving
continuous motion and running on pairs of sprocket wheels g the chains being con-
nected by one or more cross-links which in passing over the sprocket wheels engage
an arm k between the wheels fixed on a loose sleeve having an eccentric m fixed on
it which revolves within an eye carrying a pawl n that engages with a ratchet
wheel o fast on the spindle of the roller C.
In conclusion it may be observed that it is not desirable to allow the filtering
medium to become fully charged with dust or stive, as the resistance to the air
current would thereby become excessive.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed we declare that what
we claim is;-
1st. A dust catcher, or apparatus for filtering air charged with stive, dust, or
other light particles wherein the filtering medium is composed of granular, or of
coarsely ground or comminuted material supported between or upon perforated
reticulated or otherwise apertured surfaces giving passage to the air without
permitting the escape of the filtering material.
2nd. A dust catcher, or apparatus for filtering air charged with stive, dust, or
other light particles from wheat cleaning, flour grinding, purifying or dressing
machinery, the filtering portion of which apparatus is composed of a layer of grain
or small wheat or crushed corn or bran supported between or upon perforated
reticulated or otherwise apertured surfaces giving passage to the air without
permitting the escape of the filtering material.
.
3rd. A dust catcher, or apparatus for filtering air charged with stive, dust, or
other light particles wherein the filtering medium is composed of granular or of
coarsely ground or comminuted material supported by perforated, reticulated
or otherwise apertured surfaces giving passage to the air without permitting the
escape of the filtering material, in combination with means of mechanically
withdrawing and renewing the filtering medium, substantially as described.
4th. A dust-catcher, or apparatus for filtering air charged with stive, dust, or
other light particles, constructed of a closed chest or chamber having its walls made
double and perforated, reticulated, or otherwise apertured, and the intervening space
filled with granular, or with coarsely ground or comminuted material as herein
specified, in combination with means whereby the said material is permitted to
travel downwards by its own gravity for the purpose of withdrawing and replacing
the foul material, substantially as shewn and described.
5th. A dust catcher or apparatus for filtering air charged with stive, dust, or
light particles constructed of a closed chest or chamber having its longitudinal side
walls made double and perforated, reticulated or otherwise apertured and the
intervening space filled with granular, or with coarsely ground or comminuted
material and being closed at bottom by fluted rollers situated within the main

page_text: chamber and receiving intermittent rotary motion for the purpose of discharging
portions of the material into the main chamber, and having an air passage com-
municating with the interior of the chest and provided with a screw conveyor for
supplying fresh material to the upper part of the filtering walls, and a second
conveyor for removing the foul material from the lower part of the chest, the said
rollers and conveyors being operated by mechanism, all as herein described and
illustrated in the drawings.
Dated this 18th day of October 1886.
W COMERFORD.
JAB COMERFORD.
By A. M. & Wm Clark, Patent Agents,
53, Chancery Lane, London.