U.S. patent number 3,669,265 [Application Number 04/842,540] was granted by the patent office on 1972-06-13 for classifying apparatus with adjustable fines outlet.
Invention is credited to Kurt H. Conley.
United States Patent |
3,669,265 |
Conley |
June 13, 1972 |
CLASSIFYING APPARATUS WITH ADJUSTABLE FINES OUTLET
Abstract
In a centripetal classifier an adjustable "fines" outlet opening
is provided consisting of a circular array of vertical elongated
trapezoidal segments which are mounted by shafts through apertures
in a horizontal apron. There are five "control" segments spaced
equally around the circle whose lower shaft ends engage five
respective arcuate slots in a rotatable cam plate disposed beneath
the apron. Between adjacent ones of the control segments are
located four interleaved "slave" segments having shorter shafts
which do not engage the arcuate slots. A horizontal rod is attached
to the cam plate and passes through the enclosure and terminates in
a handle outside of the enclosure. When the handle is pulled out or
pushed in, the cam plate rotates and the lower shaft ends of the
control segments are tilted inwardly or outwardly thereby tilting
or pivoting the trapezoidal segments outwardly and inwardly to
change the effective size of the outlet opening and hence the fines
"cut." Since the control and slave segments are interleaved, the
slave segments are similarly caused to pivot.
Inventors: |
Conley; Kurt H. (Hamden,
CT) |
Family
ID: |
25287581 |
Appl.
No.: |
04/842,540 |
Filed: |
July 17, 1969 |
Current U.S.
Class: |
209/135; 203/88;
203/95; 209/722; 203/67; 203/90; 203/97 |
Current CPC
Class: |
B04B
5/12 (20130101); B02C 13/14 (20130101) |
Current International
Class: |
B04B
5/00 (20060101); B02C 13/14 (20060101); B02C
13/00 (20060101); B04B 5/12 (20060101); B04c
003/06 () |
Field of
Search: |
;209/139A,144,154,211,493,495 ;241/59-61 ;251/212 ;55/393 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
628,622 |
|
Oct 1927 |
|
FR |
|
22,540 |
|
Aug 1910 |
|
GB |
|
767,895 |
|
Feb 1957 |
|
GB |
|
908,042 |
|
Oct 1962 |
|
GB |
|
Primary Examiner: Lutter; Frank W.
Assistant Examiner: Hill; Ralph J.
Claims
I claim:
1. In the classifying apparatus including means for introducing a
mixture of various-sized particles and means for causing said
mixture to move in an inwardly-spiraling flow in a predetermined
direction parallel to the axis of said spacing flow, the
combination comprising:
a. an outlet opening assembly disposed within said apparatus
substantially concentric with said spiral flow in the path of said
flow downstream of said introducing means, said assembly including
variable means for varying the effective cross-sectional area of
said opening thereby to intercept and remove from said mixture a
predetermined inward fraction thereof and
b. means coupled to said assembly and extending outside of said
apparatus for operating said variable means.
2. The invention according to claim 1 wherein said variable means
comprising a plurality of interleaved segments.
3. The invention according to claim 2 wherein said segments include
a plurality of control segments which are directly caused to change
their angular position by said adjusting means and a plurality of
slave segments which are interleaved with one another and with said
control segments and are thereby impelled indirectly to assume the
same angular position as said control segments.
4. The invention according to claim 3 wherein said control segments
have attached thereto shafts and wherein said adjusting means
includes a rotatable cam plate located in a substantially
horizontal plane in proximity to said control segments and having a
plurality of arcuate slots each of which is engaged by at least one
of said shafts, and also includes a lever coupled to said cam plate
for causing rotation thereof, said lever being accessible outside
said apparatus.
5. The invention according to claim 4 wherein said slave segments
are attached to shafts which are shorter than the shafts attached
to said control segments and said assembly includes a generally
horizontal annular apron between said slave and control segments
and said cam plate, said apron having a circular array of apertures
through which said shafts of said slave and control segments
respectively extend and wherein means are provided which prevent
said slave and control segments and their associated shafts from
being detached from said cam plate yet allows them to pivot about
substantially horizontal axes in response to movement of said
control segments upon rotation of said cam plate by said lever.
6. The invention according to claim 2 wherein said interleaved
segments are upstanding and mounted for pivoting about respective
horizontal axes and are attached to respective shafts and wherein
said adjusting means includes an externally operable cam plate
which is engaged by at least predetermined ones of said shafts
thereby to cause said segments to tilt about their axes in response
to operation of said plate.
7. The invention according to claim 6 wherein said cam plate is
mounted for rotation within its own plane.
8. The invention according to claim 1 wherein said adjusting means
includes externally operable cam means which engages said variable
assembly.
9. The invention according to claim 1 wherein said spiralling flow
is also generally downward.
10. The invention according to claim 1 wherein said variable means
varies the axial location of said opening of said assembly in said
direction of flow.
11. In a classification apparatus which comprises means toward the
upper end thereof for feeding a mixture of various-sized solid
particles, means including a chamber defined by an apertured wall
extending downward from said feeding means for creating a first
spiral flow of gas, the improvement which comprises: an assembly
disposed toward the lower end of said apparatus substantially
concentric with said flow which has an outlet opening means having
a variable cross-sectional area for removing a predetermined
central fraction of the particles in said flow and means coupled to
said assembly and accessible on the outside of said apparatus for
adjusting the area of said opening means.
12. The invention according to claim 11 wherein said variable
outlet opening includes a circular row of substantially vertical
segments which are pivotable about respective horizontal axes in
response to operation of said adjusting means.
13. The invention according to claim 12 wherein said assembly rests
on the terminal portion of a conduit adapted to be connected to a
suction source.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to classifiers, especially centripetal
classifiers having an axial take-off of the finer particles of a
mixture of particles to be classified.
2. Prior Art
In centripetal classifiers, as exemplified by the one shown in U.S.
Pat. No. 3,433,422 issued to W. P. Guenther, the "fines" take-off
was located centrally toward the bottom of a generally cylindrical
classifying chamber. The "cut" at which the fines were extracted
from the descending spiralling mixture depended upon the effective
area of the mouth of the outlet but it was necessary to disassemble
the lower portion of the apparatus to substitute an outlet opening
of a different size when the fines cut was to be modified. The
present invention obviates disassembly of the apparatus for
changing the effective cross-section of the opening by removing
and/or substituting a differently shaped or sized outlet.
BRIEF SUMMARY OF THE INVENTION
In a classifier wherein pulverulent material is to be classified by
creating an inwardly spiralling current of a gas (air) transverse
to the falling material, thereby to produce a downwardly spiralling
flow of centripetally classified product, an outlet opening is
provided intermediate the beginning and ending point of the flow
whose size may be manually varied from outside the apparatus.
Variations in its size determine the fines cut. In the form shown
the outlet comprises a plurality of interleaved upstanding segments
which, in response to push-pull movement of an external handle,
pivot in unison about their respective horizontal axes thereby to
vary the "capture" cross-section of the outlet opening.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side-elevation view of the apparatus according to the
present invention with the main features shown in full lines and
the rest in phantom lines.
FIG. 2 is a side-elevation schematic view of the apparatus shown in
FIG. 1 and showing the general flow path of the particles processed
in the apparatus shown in FIG. 1.
FIG. 3 is a sectional view of the apparatus shown in FIG. 1 taken
along the section lines 3--3 thereof.
FIG. 4 is an enlarged view of part of the apparatus shown in FIG.
3, partly broken away.
FIG. 5 is an enlarged side elevation view of one of the components
shown in FIG. 4.
FIG. 6 is an edge view of the apparatus shown in FIG. 5.
FIG. 7 is an edge view of another of the components shown in FIG.
4.
FIG. 8 is an exploded view, partly in phantom of some parts of the
apparatus shown in FIG. 1.
FIG. 9 is an enlarged sectional view of part of the apparatus shown
in FIG. 3 and taken along the section line 9--9.
FIG. 10 is a sectional view of part of the apparatus shown in FIG.
3 taken along the section line 10--10.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring now to FIGS. 1 and 2 in particular, there is shown
generally at the numeral 20 a combination centrifugal impacting
mill-classifying apparatus. It includes a mill section A and a
classifying section B. The mill section comprises an upper casing
21 in which are formed two feed or input chutes 22. A motor shaft
23 passes through the casing 21, the upper portion of the shaft 23
being coupled by a conventional means to an appropriate source of
rotary power such as a motor (not shown).
Within the casing 21 there is located a depending generally annular
stator 28 which is fixed to the lower surface of the casing 21 by
welding, for example, or by any other means. The stator 28 includes
a plurality of circular concentric rows of depending stator
impacting elements 29.
The shaft 23 is connected at its lower end to a rotor indicated
generally at the numeral 25 which includes, for example, three
concentric rows of upstanding impacting elements 27. The material
to be milled and classified is fed in through the chutes 22 and
drops onto the surface 25a whence it is flung outwardly at high
speed against the interdigitating rows of impactors 27 and 29
which, by centrifugal impact, reduce the size of the product into a
mixture of coarse, intermediate and fine particles as may be seen
in FIG. 2. This stream proceeds spirally down the length of the
classifying chamber whose construction will now be explained.
The classification chamber is bounded substantially by the
apertured wall 30 having apertures 33 formed therein. Surrounding
the chamber 32 and acting as air inlet guides are a plurality of
curved vanes 31 which are welded or otherwise fixed at their bottom
edge to the generally annular flange section 35a. It is these vanes
which, when a suction device (not shown) is connected to the
external end of the conduit 34, guide the air into the
classification chamber to produce an inwardly spiralling current of
air generally transverse to the axis of the apparatus 20. Conduit
34 is attached to the adjustable-diameter iris assembly 37. The air
entering the chamber in the region thereof above the upper edge of
the iris assembly 37 and the effects of gravity on the particles
issuing from the mill section A cause the particles to flow in this
region as shown in FIG. 2. The curved vanes 31 help to impart the
inwardly spiralling motion to the incoming air.
In the region of the chamber 32 below the upper edge of the iris
37, the air will tend to come inwardly in a spiral flow, then be
obstructed by the sides of the iris 37 and then be forced upward as
more air comes in due to the suction in conduit 34. This inward and
upward current in the lower region of the chamber 30 will tend to
bring upwardly any fine particles which may have fallen down past
and outwardly of the upper edge of the iris assembly 37. When these
finer particles are carried up into the region of the upper edge of
the iris 37 they are sucked down through inlet opening 37a and then
out of the apparatus through the conduit 34.
All of the foregoing operation of the mill-classifying apparatus is
substantially identical to the operation of the apparatus described
and claimed in U.S. Pat. No. 3,433,422 issued Mar. 18, 1969 and
referred to above. Shown in that patent, instead of the adjustable
iris 37, was a conical member with a fixed effective outlet area.
It was therefore impossible to change the fine "cut" of the
particle flow taken out along the axis of the classification
apparatus without changing the conical section itself from within
the chamber 32.
In accordance with the present invention the iris assembly 37 is
made to have an effective upper inlet diameter and shape adjustable
from outside the apparatus 20. A handle 38a is attached to the
segments 45 (FIG. 10) of the iris 37 in such a way that pushing and
pulling the handle inwardly and outwardly causes the segments to be
pivoted between their most inwardly and outwardly inclined
positions (FIG. 10) as well as all intermediate positions.
Referring now in particular to FIGS. 3-10 it will be seen that the
iris assembly 37 including the generally annular apron 36 and the
lower pan-shaped member 39 are all supported within the chamber 32
by the upper end 34a of the conduit 34. The conduit 34 passes
through the coarse particle collecting hopper 35 whose lower end is
connected to a drum (not shown) or other collecting container. The
most coarse particles move downwardly past the outer edges of the
apron 36 and the member 39 and into the coarse-receiving hopper 36
as shown in FIG. 2.
The apron 36 is substantially frustro-conical and its upper
horizontal surface 36c is formed to include a circular row of
circular openings or holes 36a which alternate with a plurality of
elongated slots 36b. From FIG. 4, it will be observed that every
fifth hole 36a is engaged by a long mounting shaft 46 attached by
bifurcated portions 46b and 46c to one of the segments 45 whereas
the intervening four circular openings are engaged by the
relatively short shafts 48 attached by bifurcated portions 48b and
48c to the segments 45. The long-shafted (46) segments 45 in the
form of the invention shown are only five in number whereas the
shorter-shafted (48) ones are 15 in number as shown. For reasons
which will become obvious those of the segments 45 connected to
long shafts 46 are known as "control" segments because they are the
only ones which are directly driven to their particular inclined
position whereas the shorter-shafted (48) segments are "slave" or
"idler" segments which are indirectly guided or driven to their
particular position by one of the control segments, either directly
or indirectly, as will be explained below.
The segments 45 are each constructed, as shown in FIGS. 5-8, of a
central triangular section 45b surrounded by inverted triangular
sections 45a and 45c which are bent inwardly with respect to the
segment 45b, all of the segments being coated with Teflon, the
trademarked tetrafluroethylene composition of the E. I. DuPont
Company. The lower ends 45d and 45e of the segments 45a and 45c
engage the slots 36b on either side of the holes 36a through which
the long and short shafts 46 or 48 pass.
By reference to FIG. 4 it is seen that the segments 45 are
overlapped so that when the long-shafted (46) control segments are
inclined inwardly, they will force the four adjacent (clockwise)
segments 45 inwardly. Conversely, when the control segments are
pivoted outwardly, each one will urge the adjacent
(counter-clockwise) four idler segments outwardly.
Just below the apron 36 and within the pan-shaped member 39 is a
cam-plate 41 whose circumferential edge is held in place for
rotation of the plate between four nylon rollers 49.
The rollers 49 are themselves mounted by means of pins 51 passing
upward through them and through holes in the base of the member 39.
The cotter pins 52 keep the pin 51 from moving downward. There are
five arcuate slots 41a formed in the plate 41. Attached to the
cam-plate 41 via pin 40 is a member 38b which itself is connected
to a rigid member 38a. Member 38a passes through a hole 39a in a
member 39 and through hopper 35 and terminates in a bent handle
38a.
It will be seen that only the lower ends of the long shafts 46 are
disposed in the arcuate segments 41a (FIGS. 4 and 10). All of the
control segments 45 are fixed to the long shafts 46 and are kept in
place by virtue of their associated shafts 46 which pass through
the circular openings 36a whereas portions 45d and 45e fit into the
elongated slots 36b. Just below the openings 36a there are a
plurality of rubber or other resilient washers 54 which also act to
seal those openings. These washers are held in place by rigid
washers 55 that are kept up by cotter pins 56 that are passed
through holes 46a formed in shafts 46.
The shorter shafts 48 do not engage the arcuate slots 41a of the
cam-plate 41. Instead, as shown in FIGS. 8 and 9, they pass through
associated ones of the holes 36a, through the resilient washers 54
and aligned rigid washers 55, and are maintained in place by cotter
pins 56 which pass through the transverse holes 48a therein.
It is seen that circular movement of the cam-plate 41 will cause
the control shafts 46 to pivot between two extreme positions
defined by their location in the slots 41a. As shown in FIG. 4, the
lower ends of shafts 46 are in their innermost position, whereas
the segments 45 attached thereto are inclined most outwardly. This
position is also shown in full lines in FIG. 10. Conversely, when
the lower ends of the shafts 46 are in the position shown in
phantom lines in FIG. 10, their associated segments 4 are inclined
inwardly to the greatest extent.
As stated before when the control segments pivot inwardly and
outwardly they necessarily cause the adjacent slave segments 45 to
move the same way.
While the invention has been shown in terms of a segmented variable
iris structure it should be appreciated that there are many other
ways (not shown) of producing an adjustable inlet opening for the
suction conduit 34. For example, the segments 45 might be made as
moldings of a plastic material particularly suitable for contacting
the specific particles being classified, the shafts 46 and 48 being
either separate or integral.
The longer control shafts might be extended upward to the proper
height and, in lieu of individual segments, surrounded by a
stretchable band secured to said extended stems. Such a variation
would, however, assume a polygonal rather than an approximately
circular shape.
In case of a very large apparatus, the segments might be cast from
metal appropriate for contacting the particles being classified,
the shafts 46 and 48 being either separate or integral.
* * * * *