Improvements in Dust Collectors.
Year: 1894

page_text: Date of Application, 6th Mar., 1894-Accepted, 12th May, 1894
COMPLETE SPECIFICATION.
Improvements in Dust Collectors.
A communication by GEORGE SCOTHEN WILSON, of Tecumseh, in the County
of Lenawee and State of Michigan, United States of America, Miller.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street,
Manchester, both in the County of Lancaster, and 323 High Holborn in the
County of Middlesex, Civil Engineer, 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 dust collectors, and consists in certain improvements
hereinafter specified and claimed.
In the drawings :
Figure 1 illustrates a vertical elevation of the improved dust collector, having
one form of automatic discharge.
Figure 2 is a vertical sectional view, showing its connection with the purifier.
Figure 3 is a vertical sectional view, showing improved means of discharge.
Figure 4 is a horizontal sectional view on the line x-x of Figure 3.
Figure 5 is a sectional representation of a modified form of the discharge.
Figure 6 is a cross section thereof on the line -..
Figure 7 is a cross section of a portion of Figure 3 on the line y-y.
Similar letters refer to similar parts.
A, represents a case. B represents the fan case, enclosing the fan C, both of
which are of the ordinary construction, and will need no further description.
In
At D is an opening into the case A, communicating with the interior of the fan
case, and through which the dust laden air is forced into the case A. E is a wind
trunk leading from the eye of the fan into the dust producing device.
Figure 2, this is shown to be a middlings purifier of the ordinary construction, the
wind trunk E leading at E' from the space therein above the grading sieve.
F is a head, in shape and size adapted to removably fit the interior of the case A.
This head is perforated with holes which are preferably round, as shown in
Figure 4. At the lower end of the machine is a similar head F. G is a spout,
trough, or receptacle which is located underneath the machine, as shown in
Figures 1, 2, and 3, and which may contain, if desired, in its bottom a valve G2, as
shown in Figure 1, or conveyors, as shown in Figures 2 and 3, and in detail in
Figures 5, 6 and 7. The upper edge of this spout is preferably of substantially
the same size and shape as the casing A. Inside of the casing A, a ledge a' is
formed, upon which rests the head F, as shown in Figure 2. Connecting the
heads F and F are canvas tubes H H, which are fastened interiorly in the holes of
the heads respectively, and are preferably from five to seven feet in length. They
thus connect the two heads by canvas flues, in a manner analogous to that of the
Hue sheets and tubes of an ordinary upright tubular boiler. The upper ends of
these canvas tubes open into a space or air chamber in the casing A, which, as
before stated, communicates with the fan and fan case. The lower head F' is
preferably so arranged that it falls slightly short of the upper edge of the hopper or
spout, and the two are connected by preferably a canvas wall, although any elastic
substance, such as leather, might be used. This is illustrated in Figure 2 at F.
In this form, means are shown for keeping the cloth tube stretched, consisting of a
centrally located spiral spring S, rigidly attached to a support below, and connected
by appropriate means with the central portion of the head F', in such manner that

page_text: the tension of the spring is exerted against the canvas tubes HH, and thereby
keeps them in a constant state of tension. This spring may be made adjustable by
the nut S³, it being obvious that the canvas casing F2 would yield as the tubes are
stretched under the tension of the spring. In the other forms of the device, means
are shown for keeping the tubes H H stretched by attaching the spouts directly to
the head F, this is shown in Figures 1 and 3, whereby the weight of the head and
attachments constantly keeps the tubes in a state of tension. This automatic
meaus of keeping the tubes in a constant state of tension, is an important feature of
this invention. It is well known that canvas, under use substantially as herein
described, constantly tends to stretch, and if it is rigidly fastened by its edges to a
rigid support, although it may be drawn tightly at the beginning of its use,
it soon
becomes loose and baggy, and this in dust collectors seriously interferes, if not
almost entirely destroys, its usefulness. The means herein suggested obviously
take up any stretching or slack in the canvas, and the consequence is that it is kept
in a uniform state of rigidity in the direction of its length.
It is obvious that the heads may be made of any assignable weight, or that
weights may be added to them so as to make the tension adjustable, if desired,
analogous to the tightening of the spring already described.
A very efficient
means of cleaning the canvas tubes has been discovered in this connection which
could not otherwise be used, except that it was kept taut under all conditions.
This means consists in utilizing the vibration due to the continuous jar of the mill
in its operation. The jar sets up a series of waves or vibrations throughout the
canvas, which tends to dislodge any material which otherwise would collect in its
interstices.
In order to prevent the lodging of dust upon the upper surface of the head F
and between the perforations and mouths of the tubes, conical or prismatic erections
are built thereon, as shown at M M in Figures 2 and 4.. The bases of these caps
extend preferably slightly over the edges of the apertures in head F, as shown in
Figures 2 and 4 for the purpose of preventing the too sudden action of the dust
laden air upon that portion of the canvas adjacent to the head, which, if permitted,
would soon cut it out and destroy it.
As shown in Figure 1, the air is permitted to escape directly from the canvas
through the pipes H H, the pipes retaining the dust, which falls through to the
hopper below, the air escaping into the surrounding atmosphere. As shown in
Figure 2, the devices are combined with the purifier, largely illustrating how it
may be combined with any mechanism producing dust and operating by means of a
so-called air current. In this figure, N represents the body of an ordinary
purifier. As common with such devices, it possesses a grading sieve located
therein, and through which the material to be bolted passes, against a current of
air which is drawn upward through the sieve. The wind trunk above the grading
sieve communicates to the fan, as herein before described; while the wind trunk
below the sieve communicates with the continuation of the casing A, enclosing the
dust collector entirely from the atmosphere surrounding it.
It is obvious that, upon appropriately operating the fan, the air will be drawn
through the grading sieve, carrying with it the dust laden particles, forcing them
into the dust collector, and the air, passing through the walls of the tubes HH,
leaves behind it the dust which falls into the hopper below, the air returning into
the casing of the purifier underneath the grading sieve.
It is obvious that the air would pass directly down through the tubes into the
hopper, and escape therefrom, if some means were not used to compel its passage
through the walls of the tubes; and, unless it passed through the walls of the
tubes, the tubes would not be kept circumferentially strained, but might more or
less collapse, nor would the dust be strained out of the air. It is also obvious that
some means must be employed for carrying away the dust, without permitting the
escape of the air with it. In Figures 1, 3 and 5 such means are shown,
that in Figure 1 consisting of an automatically weighted valve G³, which in itself
is not new.

page_text: It is obvious that when the load of dust exceeds the weight of the counter-
balance V, the valve will open and allow the dust to escape, while it will instantly.
close thereafter. Accumulation of dust thereon seals it, and prevents the escape
of air through the valve, and this compels the air to pass through the walls of the
tube.
In Figures 3 and 5 a means of sealing is shown, in connection with another form
of the apparatus which consists of a conveyor N located in the bottom of the'
trough or hopper G. The conveyor is of the ordinary construction, and carries.
the material out in the direction of the arrow and through an opening N2 into any
appropriate receptacle. Closely surrounding the upper portion of the axis of the
conveyor is an extension of the said wall at O. This extension, together with an
extension of the trough beyond the opening underneath this extension O, at o, the
extension of the trough being marked P, forms a shelf or ledge outside of the
conveyor proper, and beyond the opening o upon which dust will accumulate until
its accumulations crowd it along, and it passes out through the opening N² herein-'
before described. This keeps the opening at o continually sealed against the
passage of any air passing through the tubes H H.
In order to provide for the even distribution of material in the conveyor trough,'
two means are shown, one in Figures 3 and 7. This consists of a couple of cant
boards, arranged in a V form, with the angle uppermost, and marked R. This
compels the falling material to be evenly distributed upon the sides of the conveyor,
without falling directly upon it. In Figures 5 and 6 a rotating shaft is shown
located above the conveyor, in which is distributed a series of short pins, which,"
when rotating, breaks up the falling material, and compels its even distribution
upon the conveyor. The shaft is marked T, and the pins t.
As it is often convenient, and in fact quite necessary, to be able to clean and
repair one series of dust collecting devices while the mill is still in operation, in
Figures 3 and 4 a compound dust collector has been shown, with means for
permitting the dust laden air to enter one or the other or both at the option of
the operator. It consists of two of the simple form of dust collectors placed
adjacent to each other, as shown in Figure 4, the wind trunk leading into both of
them at openings also contiguous, marked W W. The partition between the two
divides this opening centrally, dividing the two dust collectors at w.
Upon the
edge of this partition is hinged valve V2. As shown in the central position, it
permits dust laden air to enter both dust collectors. As shown in the dotted line,
it closes off the left hand collector. By swinging it to the opposite side, it would
close off the right dust collector. In connection therewith, the partition is
continued below into the upper and conveyor spout, as shown at A³. It extends
down closely around the conveyor shaft at A', leaving an opening underneath, A.
As the flights on the conveyor shaft do not extend through this opening, there
results therein an accumulation of dust, being continually crowded therethrough
by the flights behind it. This is analogous to the sealing of the opening o, herein-
before referred to. It results that when but one of the dust collectors is being
used, the air is sealed off from the other one, but above and below without any
change whatever in the mechanism of the conveyors, and with simply the shifting
of the valve V2.
The operation of the device is sufficiently clear from its description.
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 by my foreign correspondent, I declare that what I claim is :—
1. In a dust collector, the combination of a chamber, a fan adapted to deliver
dust laden air therein, a series of circular canvas tubes, open at each end, the
upper open ends communicating with said chamber, into which said dust laden air
is delivered, the open lower ends communicating with a common dust receptacle,
substantially as described.
2. In a dust collector, the combination of a chamber, a fan adapted to deliver

page_text: dust laden air therein, a series of circular canvas tubes open at each end, the upper
ends communicating with said chamber and adapted to receive the dust therefrom,
the open lower ends communicating with a common dust receptacle, means for
conveying away the dust collected and means for keeping the cloth tubes in a
"constant state of tension in the direction of their length, substantially as
described.
3. In combination with a chamber having a suitable inlet opening, a fan case and
fan connected therewith by suitable passages and adapted to deliver dust laden air
into said casing, a series of cloth tubes leading therefrom downward and being open
and unobstructed throughout their whole extent, a dust receptacle communicating
with the lower open end of said tubes and having therein an automatic valve
adapted to keep said dust chamber substantially air tight and adapted to
automatically discharge therefrom collections of dust therein, substantially as
described.
4. In combination with a casing having a suitable inlet opening, a fan case and
a fan connected therewith by suitable passages, and adapted to deliver air into said
casing, a series of unobstructed cloth tubes leading therefrom downward, adjustable
means for keeping said tubes in a constant state of longitudinal tension, a dust
receptacle communicating with the lower ends of said tubes and having therein
an automatic valve adapted to keep said dust chamber substantially air tight,
- and adapted to automatically discharge collections of dust therein, substantially as
described.
5. In combination with a casing having a suitable inlet opening, a fán case and
a fan connected therewith by suitable passages and adapted to deliver therein
dust laden air, a series of cloth tubes leading therefrom downward, a perforated
head common to two or more of the flues and sustained by the lower ends thereof,
whereby the said tubes are kept in a constant state of tension, a dust receptacle
communicating with the lower ends of said tubes, and means for discharging the
dust from said dust receptacle, substantially as described.
6. In combination with a casing having a suitable inlet opening, a fan case and
a fan connected therewith by suitable passages to cause a downward current, a
series of cloth tubes leading therefrom downward, the opening into the upper end
of said tubes being choked or rendered smaller in diameter than the diameter of
the tube proper, means for keeping said tubes in a constant state of tension, and a
dust receptacle communicating with the lower ends of said tubes, substantially as
described.
Dated this 5th day of March 1894.
WM. P. THOMPSON & Co.,
Agents.