An Improved Method of and Apparatus for Separating Dust from Air, chiefly Designed for Use in Flour Mills.
Year: 1884

page_text: An Improved Method of and Apparatus for Separating Dust
from Air, chiefly Designed for Use in Flour Mills.
[Communicated from abroad by The M'Intyre Manufacturing Company,
of Lockport, New York, United States of America.]
I WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents,
Southampton Buildings, London, in the County of Middlesex, do hereby declare
the nature of said invention for "AN IMPROVED METHOD OF AND APPARATUS FOR
SEPARATING DUST FROM AIR CHIEFLY DESIGNED FOR USE IN FLOUR MILLS"
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 dust-collectors which are employed in
mills for freeing the air discharged from middlings-purifiers and similar machines
from the dust or solid particles which it contains.
In dust-collectors as ordinarily constructed the dust-laden air is sifted or strained
through a cloth which intercepts the dust and permits the air to pass through.
These filter-cloths are an obstruction in the air-passage whereby the air-current is
retarded necessitating a proportionately greater. speed of the fan in order to effect
the desired separation on the purifier-sieve. The resistance which the filter-cloth
opposes to the air-current increases as the meshes of the cloth become filled with
dust and decreases as the meshes are cleared by the jarring devices or brushes
with which dust-collectors are usually provided, so that this resistance is variable,
causing corresponding variations in the force of the air-current and an unequal
purification.
The object of this invention is to overcome these difficulties by separating the
dust from the air without the use of filter-cloths, and it comprises a method and
apparatus whereby the dust is separated from the air by centrifugal force acting
upon the dust-particles in such manner as to drive them out of the air-current
into a collecting chamber while the air is permitted to move on, as hereinafter fully
set forth.
In the accompanying drawing
Figure 1 is an end elevation, and

page_text: Figure 5 is a cross section drawn to an enlarged scare, or a portion of the aust
collecting case.
Figure 6 is a longitudinal section of the trapped dust discharge.
Figure 7 is a cross-section on the line ¹¹ Figure 6.
Figures 8 and 9 are cross sections on the line y, y Figure 6, showing the different
positions of the valve.
Similar letters of reference indicate corresponding parts in the several Figures.
A indicates the centrifugal dust-separator, and a the spout or conduit through
which the dust-laden air is conducted from the middlings purifier or other machine
to the separator. The horizontal shaft b of the separator turns in bearings b' and
is provided with a driving pulley B. The wings or beaters C of the separator are
fastened to the outer side of a dished head or disc D which is secured to the
shaft b.
E indicates a chamber arranged opposite the receiving ends c of the beaters C
and communicating with the spout a so as to conduct the dust-laden air between
the inner or receiving ends c of the beaters. The latter extend outwardly and
forwardly on the outer side of the head *D, and are provided with a curved shield
or hood F which encloses the spaces between the beaters from their receiving
ends e to a point near the outer horizontal edges of the beaters, whereby the air
which is drawn between the beaters is compelled to move onward in the direction
of the arrow in Figure 3, and prevented from being blown backward into the
chamber E.
G indicates the dust-collecting chamber which surrounds the revolving beaters C.
The inner wall of this chamber is formed by a perforated cylindrical shell g
arranged in close proximity to the outer edges of the beaters. The upper portion
of the outer wall of the chamber G is made concentric with the perforated shell g,
and its lower part has the form of a hopper, as shown at gl, and is provided at its
bottom with a conveyer trough H and a screw conveyer h, whereby the dust falling
into the hopper is removed.
The perforations in the shell are preferably made in the form of horizontal
slots having their rear edges- projecting inwardly beyond the inner surface of
the shell g, as shown in Figure 5, to facilitate the entrance of the dust into the
openings.
The trough His provided with a trapped discharge, whereby the dust is
delivered from the chamber G without permitting the air to escape with it. This
trapped discharge is preferably constructed in the following manner, that is to say
jindicates the partition arranged in the conveyer trough H near its discharge end,
and an opening formed in the lower portion of the partition for the discharge of
the material from the trough proper into the space between the partition j and the
nd wall of the conveyer trough.
The
L indicates a rotating hollow cylindrical valve secured to the shaft h¹ of the
conveyer between the partitions and . The inner wall of the valve Lis
provided with an opening , on one side of the shaft, which is adapted to register
with the opening in the partition j, once in every revolution of the valve.
periphery of the valve Lis constructed with an opening m which is adapted to
register with an opening n formed in the bottom of the space between the
partitions and . The opening mis arranged diametrically opposite the
opening, or so that the coincidence between the openings, mand n is broken
when the openings k and register, and vice versa, so that the opening n is closed
by the cylindrical wall of the valve L when the conveyer discharges the material
through the openings and into the cavity of the valve. The material so
delivered into the valve is permitted to escape from the same through the
openings m and n when the opening is closed by the inner head of the valve L,
and by this means the escape of air through the dust-discharge is prevented and
air-currents in the chamber G are avoided.
o and o' indicate the end walls of the chamber G. The wall o is provided with
an opening of through which the dust-laden air enters from the chamber E into

page_text: the space between the receiving ends of the beaters C. The hood F fits snugly in
this opening to prevent, as far as practicable, the air from passing along the outer
side of the hood.
The wall o¹ is provided with an opening o³ through which the air which has
been freed from dust escapes from the separator A.
P indicates a suction fun mounted on the shaft b and arranged in a casing p
contiguous to the wall o¹, the opening o³ in the said wall forming the eye of the
fan-case p.
The fan P draws the air from the separator A and discharges the
same through its blast-spout q. If the air escaping from the spout q contains
traces of dust it may be discharged into an ordinary dust-room of sufficient size to
permit the dust to settle while the air escapes freely.
indicates an endless belt running around pulleys 71 72 mounted respectively on
the shafts b and ¹, whereby the conveyer his rotated from the shaft b. .If
desired, the fan P may be mounted on a separate shaft and driven with greater or
less speed than the separator A.
The dust-laden air enters from the chamber E between the receiving ends of
the beaters C, and is driven by the latter outwardly and forwardly in the direction
of the arrows in Figure 3.
The centrifugal action of the beaters C drives the dust against the surrounding
perforated casing g. The air is prevented from entering the said casing as the
latter is not provided with any outlet for air, but the dust, owing to its greater
specific gravity, is driven through the perforations of the casing g into the
chamber G and drops in the latter upon the hopper-shaped bottom and thence into
the conveyer trough H from which it is removed by the intermittent action of the
discharge device. The projecting rear edges of the slots i in the casing g.greatly
facilitate the entrance of the dust into the chamber G as they intercept the dense
layer of dust which is driven by the beaters C along the inner surface of the
casing g in the direction of the arrow in Figure 5.
The dust is, in this manner, separated from the air by the centrifugal action of
the beaters driving the dust out of the air-current which moves through the
seperator A between the head D and hood F, while the air which has been freed
from dust is permitted to move on toward the fan P.
The seperator A accelerates the movement of the air through the machine
instead of retarding it like ordinary dust-collectors which operate by filtering or
straining the air through cloths, and as the operation of the seperator A is uniform
at all times, it ensures the uniform and regular operation of the purifying machines
with which it is connected.
When the centrifugal separator is sufficient to create the desired air-current the
auxiliary fan may be omitted.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed I declare that what
I claim is
First. The herein described method of separating dust from air, which method
consists in driving the dust particles out of the air-current by centrifugal force
into a closed receiving chamber, while the air which has been freed from dust is
permitted to escape in a different direction, substantially as set forth.
Second. In a machine for separating dust from air, the combination of revolving
beaters, a closed receiving chamber having an inner perforated wall surrounding
te said beaters, and inlet and outlet openings through which the dust-laden air is
conducted to the beaters and the purified air is permitted to escape therefrom,
substantially as set forth.
Third. In a machine for separating dust from air, the combination of revolving
beaters, a closed receiving chamber having an inner perforated wall surrounding
the said beaters, inlet and outlet openings through which the dust-laden air is
conducted to the beaters and the purified air is permitted to escape therefrom, and
a trap; ed discharge-device whereby the dust is removed from the closed chamber
without permitting the air to escape therefrom, substantially, as set forth.

page_text: Fourth. In a machine for separating dust from air, the combination of revolving
beaters, a closed receiving chamber having, an inner perforated wall surrounding
the said beaters, inlet and outlet openings through which the dust-laden air is
conducted to the beaters and the purified air is permitted to escape therefrom, and
an auxiliary fan whereby the air is caused to flow through the separator,
substantially-as set forth.
Fifth In a machine for separating dust from air, the combination of revolving
beaters with a closed receiving chamber having its inner wall constructed with
openings having inwardly projecting rear edges, substantially as set forth.
Sixth. The combination with the chamber G having an inner perforated wall g
of revolving beaters C, a head D to which the beaters are secured, and a hood F
by which the spaces between the receiving portions of the beaters are closed,
substantially as set forth.
-
+
1
100
HASELTINE, LAKE & Co.,
For the Applicant.