U.S. patent number 3,907,213 [Application Number 05/466,302] was granted by the patent office on 1975-09-23 for impact scrubber.
This patent grant is currently assigned to National Engineering Company. Invention is credited to John H. Kauffman.
United States Patent |
3,907,213 |
Kauffman |
September 23, 1975 |
Impact scrubber
Abstract
An impact scrubber for removing coating materials from the
surfaces of particulate matter such as foundry sand and the like
comprises a lift tube having an inlet end and an opposite end for
containing a high velocity fluidized stream of said matter, fluid
injector means spaced adjacent said inlet end for carrying said
particulate matter into said inlet end and forming a fluidized
stream of said matter in said lift tube, movable deflector means
adjacent and in communication with said opposite end for directing
said fluidized stream angularly outward with respect to a
longitudinal axis of said lift tube for discharging said matter
therefrom, support means for rotatively supporting said deflector
means for directing said discharge therefrom in a selected one of a
plurality of relative rotative positions, and means for separating
the coating materials removed by impact from said particulate and
said particulate matter.
Inventors: |
Kauffman; John H. (Richland
Center, WI) |
Assignee: |
National Engineering Company
(Chicago, IL)
|
Family
ID: |
23851253 |
Appl.
No.: |
05/466,302 |
Filed: |
May 2, 1974 |
Current U.S.
Class: |
241/40;
241/DIG.10; 451/89; 451/88 |
Current CPC
Class: |
B22C
5/10 (20130101); Y10S 241/10 (20130101) |
Current International
Class: |
B22C
5/10 (20060101); B22C 5/00 (20060101); B02C
019/06 (); B24C 003/00 () |
Field of
Search: |
;51/8R
;241/DIG.10,275,102,5,39,40,42 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kelly; Donald G.
Attorney, Agent or Firm: Mason, Kolehmainen, Rathburn &
Wyss
Claims
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. An impact scrubber for removing coating materials from the
surfaces of particulate matter such as foundry sand and the like
comprises at least one lift tube unit having a lift tube with an
inlet end and an opposite end for containing a high velocity
fluidized stream of said matter, fluid injector means spaced
adjacent said inlet end for carrying said particulate matter into
said inlet end and forming a fluidized stream of said matter in
said lift tube, fluid stream deflector means adjacent and in
communication with said opposite end of said lift tube, means
mounting said deflector means for rotation around a longitudinal
axis of said lift tube, said deflector means including a discharge
tube for directing said fluidized matter in a single stream
angularly outward with respect to said longitudinal axis of said
lift tube at different rotative positions, and means for rotating
said deflector means for directing said discharge tube in a
selected one of a plurality of relative rotative positions.
2. The scrubber of claim 1 including means for supporting said lift
tube in a selected one of a plurality of different axial positions
relative to said injector means wherein said spacing between said
inlet end and said injector means may be selectively adjusted.
3. The scrubber of claim 1 including a plurality of said lift tube
units, a common housing for said units having a central axis spaced
between said units, said means for rotating said deflector means
operable to position a discharge tube for each lift tube in a
selected direction facing toward said central axis or away from
said axis, and separator means including enclosures spaced on
opposite sides of said housing for receiving fluidized streams of
material discharged from said deflector means when positioned to
discharge away from said central axis, said separator means further
including means for separating said particulate matter and said
coating materials removed from the surfaces of said particulate
matter.
4. The scrubber of claim 3 wherein said supporting means includes
means for supporting each of said lift tubes in selectively
adjustable axial positions relative to their respective injector
means wherein said spacing between said inlet end and said injector
means of each unit may be varied.
5. The scrubber of claim 3 wherein said deflector means of each
unit includes a lift tube extension having a closed upper end and a
discharge tube angularly extended outwardly from said lift tube
extension and in communication therewith at a level below said
closed end.
6. The scrubber of claim 5 wherein each unit includes removable
coupling means for interconnecting a lower end of said lift tube
extension and said opposite end of said lift tube.
7. The scrubber of claim 5 wherein said housing includes discharge
openings formed on opposite sides in communication between said
discharge tubes and said separator enclosures when said deflector
means are rotated to discharge in opposite directions away from
said central axis.
8. In an impact scrubber for removing coating materials from the
surfaces of particulate matter such as foundry sand and the like,
an enclosure, flexible target means in said enclosure, inlet means
adjacent an upper level of said enclosure for directing a flow of
said matter and material against said target means, said target
means including a piece of flexible material supported from an
upper end portion to hang generally vertically in said enclosure
with a freely deflectable lower end portion spaced in front of said
inlet meaans, baffle means in said enclosure below said inlet means
for forming a curtain of downwardly flowing matter and material and
draft means for moving a flow of air through said curtain for
carrying at least a portion of said coating materials upwardly away
from said particulate matter.
9. The appartus of claim 8 wherein said draft means includes an air
inlet opening in said enclosure spaced below said baffle means and
suction means in communication with said enclosure above said
baffle means for inducing air pass into said air inlet opening and
through said curtain of material flowing downwardly of said baffle
means.
10. The apparatus of claim 8 wherein said baffle means includes at
least one sloped baffle and means for adjustably selecting the
angle of slope thereof.
11. An impact scrubber for removing coating materials from the
surfaces of particulate matter such as foundry sand and the like
comprises at least one lift tube unit having a lift tube with an
inlet end and an opposite end for containing a high velocity
fluidized stream of said matter, fluid injector means spaced
adjacent said inlet end for carrying said particulate matter into
said inlet end and forming a fluidized stream of said matter in
said left tube, deflector means adjacent and in communication with
said opposite end for directing said fluidized stream angularly
outward with respect to a longitudinal axis of said lift tube for
discharge therefrom, support means for rotatively supporting said
deflector means for directing said discharge therefrom in a
selected one of a plurality of relative rotative positions, and
means for separating said coating materials and particulate matter
including an enclosure for receiving said fluidized stream from
said deflector means, flexible target means in said enclosure,
inlet means adjacent an upper level of said enclosure for directing
a flow of said matter and material against said target means,
baffle means in said enclosure below said inlet means for forming a
curtain of downwardly flowing matter and material and draft means
for moving a flow of air through said curtain for carrying at least
a portion of said coating materials upwardly away from said
particulate matter.
12. The apparatus of claim 11 wherein said enclosure includes a
side wall, said inlet means adapted to direct a horizontal flow of
material through said side wall, and said target means comprises a
piece of flexible material supported from an upper end portion to
hang generally vertically in said enclosure with a freely
deflectable lower end portion spaced in front of said inlet
means.
13. The apparatus of claim 11 wherein said draft means includes an
air inlet opening in said enclosure spaced below said baffle means
and suction means in communication with said enclosure above said
baffle means for inducing air pass into said air inlet opening and
through said curtain of material flowing downwardly of said baffle
means.
14. The apparatus of claim 11 wherein said baffle means includes at
least one sloped baffle and means for adjustably selecting the
angle of slope thereof.
Description
The present invention relates to a new and improved impact scrubber
for removing coating materials from particulate matter and more
particularly to new and improved apparatus for reclaiming for reuse
the granular materials commonly used in foundry operations such as
foundry sand and the like. The present invention is an improvement
over the apparatus shown and described in copending patent
application, Ser. No. 332,415 filed Feb. 14, 1973, now U.S. Pat.
No. 3,825,190, invented July 23, 1974, and assigned to the same
assignee as the present invention.
In foundry operations granular base materials such as silica sand,
zirconia sand and the like are coated with binding products, for
example, clays, cereals, resins, and oils and the resulting mixture
comprises foundry sand which is shaped and molded into definite
shapes around patterns to form mold cavities. Molten metal is
poured into the cavities as castings are made. The molding sand is
subjected to direct contact with hot molten metal and the binding
products which coat the granular sand base materials are oxidized
and/or calcined in the molding process by the intense heat
involved. In order to recondition the base material for further use
in subsequent foundry operations, it is desirable to remove the
oxidized coatings from the basic sand granules and subsequently
prepare the sand as molding sand in suitable formulations with the
necessary binding products required for a mold. The oxidized or
calcined coating materials on the used molding sand granules are
generally carbonaceous in nature and also are of a generally lower
density than the basic sand material itself.
Accordingly, it is desirable to provide a system for removing the
encrusted coating material from the sand grains in a dry,
mechanical impact scrubbing process and then separate the lighter
weight coating materials from the basic sand or particulater matter
so that the clean sand may then be reused in subsequent molding
operations after reformulation with the necessary binders.
The impact scrubber of the present invention is a self-contained,
highly efficient unit, requiring a relatively small floor space,
and is automatically controlled to provide the desired
scrubbing/cleaning action as may be required for the particulate
matter being treated.
It is an object of the present invention to provide a new and
improved impact scrubber for treating particulate matter such as
foundry sand and the like, and more particularly it is an object of
the invention to provide a new and improved scrubber of the
character described which is highly efficient in operation,
automatically controlled for operation and discharge and which
requires a relatively small floor space per unit of capacity in
comparison with prior sand scrubbers.
Another object of the present invention is to provide a new and
improved impact scrubber for cleaning particulate matter having a
plurality of separate impact type sand scrubbing units and means
for controlling the direction of discharge from all of said units
simultaneously.
Another object is to provide a sand scrubber of the character
described including novel means for adjusting the application of
the individual scrubbing units for the most efficient
operation.
Another object of the present invention is to provide a new and
improved impact scrubber for cleaning particulate matter having a
novel target system for receiving the impact of the fluidized flow
of matter in order to mechanically remove the calcined or oxidized
coatings from the individual particles of matter.
Another object of the invention is to provide a new and improved,
dry process, mechanical impact type scrubber which includes a novel
system for separating the coating materials from the grains of
particulate matter.
Another object of the present invention is to provide a new and
improved impact scrubber having a plurality of individual lift tube
scrubber units and means for automatically controlling the
direction of the discharge of particulate matter for impact
scrubbing or for discharge from the scrubber itself.
The foregoing and other objects and advantages of the present
invention are accomplished in an illustrated embodiment, by way of
illustration and not limitation, comprising a dry process,
mechanical impact, scrubber for removing coating materials from the
surfaces of particulate matter such as foundry sand and the like.
The scrubber comprises one or more lift tubes, each having an inlet
end and an opposite end for containing a high velocity fluidized
stream of said matter and fluid injector means spaced adjacent said
inlet end for carrying said particulate matter into said inlet end
and forming a fluidized stream in said lift tube. Deflector means
is provided adjacent and in communication with the opposite ends of
the lift tubes for directing said fluidized stream angularly
outward with respect to the longitudinal axes of said lift tubes
for discharge therefrom. Support means is provided for rotatively
supporting said deflector means for directing said discharge
therefrom in a selected one of a plurality of relative rotative
positions. Means is provided for separating the coating materials
broken away from the grains of particulate matter and the cleaned
grains of particulate matter so that the particulate matter may be
used again.
For a better understanding of the invention reference should be had
to the following detailed description taken in conjunction with the
drawings, in which;
FIG. 1 is an elevational view with portions shown in section of a
new and improved impact scrubber for treating particulate matter
constructed in accordance with the features of the present
invention.
FIG. 2 is a transverse, horizontal cross sectional view taken
substantially along lines 2--2 of FIG. 1;
FIG. 3 is another transverse horizontal cross sectional view taken
substantially along lines 22 of FIG. 1 but showing the scrubber
units in a discharging position.
FIG. 4 is another transverse cross sectional view taken
substantially along lines 4--4 of FIG. 1; and
FIG. 5 is an enlarged fragmentary vertical sectional view taken
substantially along lines 5--5 of FIG. 4.
Referring now more particularly to the drawings therein is
illustrated a new and improved impact scrubbing apparatus for the
treatment of particulate matter such as foundry sand and the like
and constructed in accordance with the features of the present
invention. The apparatus as a whole is referred to by the reference
numeral 10 and includes an upstanding cylindrical housing 12 having
a circular base 14. At the upper end of the housing 12 there is
provided a hopper 16 for holding and receiving the sand or other
particulate matter to be processed by the scrubber. The hopper 16
includes a frustro-conical bottom wall 18 having a circular shaped
opening 20 at the lower end for feeding the particulate matter
downwardly into a cylindrical, intermediate section of the housing
referred to by the numeral 22 and separated from an upper or hopper
section of the housing by an annular wall 24. The intermediate or
discharge section 22 of the housing is similarly separate from a
lower housing section 26 by an annular wall 28.
In accordance with the present invention, the scrubber 10 includes
a plurality of vertically extending, impact type, lift tube
scrubbing assemblies or units generally indicated by reference
numeral 30. As shown in FIG. 1, each scrubber unit extends upwardly
from the lower housing section 26 through an opening in the annular
wall 28 and projects upwardly to the intermediate section 22 of the
housing. In the lower housing section 26, the scrubber units 30 are
disposed on diametrically opposite sides of an upstanding,
cylindrical, air plenum chamber 32 which is centrally positioned in
the housing 12 and extends between the circular bottom plate 14 and
the circular wall 28. The plenum chamber 32 is supplied with a high
volume flow of pressurized air from a suitable source such as a
"Rootes" type blower or equivalent via an inlet duct 34 which
extends radially outwardly of the plenum chamber and passes through
an appropriately shaped opening formed in the wall of the
cylindrical housing 12.
Each of the lift tube scrubber units 30 includes a cylindrical
outer shell 36 having an annular mounting flange 38 adjacent the
upper end secured to the wall 28 in concentric relation with a
circular opening therein by suitable fasteners such as removable
bolts 39. At the lower end each shell 36 is provided with an
annular lower end flange 40, which flanges provide support for
convergent type, high velocity, injection nozzles 42 as shown in
FIG. 1. Each nozzle 42 is removably attached to its supporting
flange 40 and is connected at its lower end via a coupling 44 with
a conduit structure in communication with the central plenum
chamber 32 for receiving pressurized air. As illustrated, the
conduit structure includes an intermediate section 46 coupled at
its lower end with a control valve 48 which in turn is
interconnected with the central plenum chamber 32 by a supply elbow
50. The supply elbows radiate outwardly from the plenum chamber and
each elbow has a lower, horizontal leg 50a and a vertical leg 50b
having its upper end connected to the lower end of a control valve
48.
In order to individually control and regulate the flow of
pressurized air from the central plenum chamber 32 to the nozzle 42
of each scrubbing unit 30, the individual valves are adjusted and
pressure gauges 52 connected to short pipe nipple sections 46 are
provided for guiding the operator in adjustment of the valves to
secure the desired rate of flow of fluid through the nozzle. The
central air plenum chamber 32 provides a high volume source of
pressurized air at relatively low pressure (inches of water) for
supplying the nozzles 42 of the lift tube scrubber units 30 and the
valves 48 are utilized for individually controlling the respective
units in accordance with the pressure gauge readings from the
gauges 52.
After periods of inactivity of the scrubber 10, sand and other
materials tend to collect in the lower end of the shells 36 and
often tends to plug the nozzles 42 to such a degree the adequate
air flow is prevented when the next start up is attempted. A high
pressure compressed air starting system is provided and this system
includes an upstanding compressed air injector 54 mounted in each
elbow 50 and designed to inject high pressure (up to 100 psi)
starting air into the material collected in elbows to clear the
passage through the nozzles 42 and the lower end of the shells 36.
The air injectors are connected to a common compressed air supply
manifold 56 and a control valve 58 is provided. The manifold is
connected to a suitable source of high pressure air.
Each cylindrical shell 36 is formed with an elongated, axially
extending access opening in the outer side wall thereof and these
access openings are sealed during operation by means of removable
or hingedly attached access doors 60. The doors permit servicing of
the interior of the shells 36 and clean out of the units if
required.
In accordance with the present invention, each lift tube unit 30
includes an elongated, vertical lift tube 62 aligned in coaxial
arrangement with an adjacent air supply nozzle 42 and spaced
vertically above the outlet of the nozzle by an adjustable distance
D. The lower or inlet end of each lift tube 62 is provided with a
replaceable annular inlet ring 64 having a slightly tapered
internal bore and the ring is adapted to receive and guide a
fluidized flow of particulate matter into the tube as it is
entrained upwardly by the air jet issuing from the nozzle outlet.
The high velocity air flow moving upwardly in the lift tubes forms
a high velocity turbulent fluidized flow of particulate matter and
air. During the entrainment of the particulate matter in the air
jet adjacent the inlet end of the lift tube and during the upward
turbulent flow within the lift tube, intense interaction between
the individual particles of particulate matter takes place in the
form of repeated random collisions. These collisions or impacts aid
in breaking up and removing the encrusted coating materials on the
sand grains and this material along with the sand is carried
upwardly in the turbulent stream.
The lift tubes 62 are adjusted in precise coaxial alignment with
the nozzles 42 by means of radial spacers 66 mounted on the shells
36 and adjustable exteriorly thereof. The spacers are provided at
upper and lower levels on the shells as shown and at each level a
plurality of spacers are provided (three or four) in order to
permit precise axial alignment of the nozzle and lift tube.
The circular wall 28 is formed with circular openings 28a spaced
radially outward of the center and in coaxial alignment with the
respective shells 36 of the lift tube assemblies 30. These openings
are substantially the same diameter as the internal diameter of the
shells 36 and the particulate matter from the chamber section 22
flows downwardly into the shells around the lift tubes 62 for pick
up by the air jets issuing upwardly from the outlet of the nozzles
42.
The elongated side access openings in the shells 36 permit the lift
tubes 62, nozzles 42 and inlet ring 64 to be serviced on replaced
without complete dismantling of the scrubber units 30. The lower
section 26 of the housing 12 is provided with relatively large,
vertical, elongated access openings or slots 68 which slots are
large enough to permit easy insertion and withdrawal of the
complete lift tube unit 30 in both an assembled or disassembled
condition.
At the upper end, each lift tube 62 is interconnected with a flow
deflector and impact assembly generally indicated by the reference
numeral 70. The deflector assembly includes a cylindrical outer
shell 72 and a centrally positioned coaxial lift tube extension 74
connected to the upper end of the lift tube 62 by a coupling 76.
Each lift tube extension 74 is supported within its shell 72 by
means of a plurality of vertical rib members 78 extending radially
outward from the lift tube extension at right angles to one another
as best shown in FIGS. 2 and 3.
Adjacent the upper end, each lift tube extension 74 is formed with
an annular end wall 80, which wall forms an outer portion of an
impact target for the upwardly moving, fluidized particulate matter
carried in the lift tube 62. As best shown in FIG. 5 the end wall
80 is formed with a central aperture therein in order to
accommodate the lower end of an elongated support rod 82 extending
upwardly therethrough. As best shown in FIG. 1, the support rods 82
project upwardly through openings provided in the circular wall 24
between the intermediate housing section 22 and an upper housing
section adjacent the level of the hopper 16. At the lower end, each
support rod is provided with a large cylindrical head 84, which
head forms the central portion of an impact target for the upwardly
moving fluidized particulate matter if the lift tube extension
74.
As best shown in FIG. 5, the upwardly flowing particulate matter
forms a pad of particulate matter in the upper end of the lift tube
extension and the pad of matter itself protects the structural
members 80 and 84 from excessive wear. The upwardly flowing matter
impacts or strikes the pad of matter formed at the upper end of the
lift tube and this causes further the oxidized coatings material to
be knocked off of the individual grains of the particulate matter.
As shown by the arrows in FIG. 5, the material rebounds downwardly
and is deflected outwardly by the upwardly moving oncoming
fluidized stream into a radially extending horizontal discharge
tube 85 forming an elbow with the lift tube extension and having an
open outer end adapted to discharge the impacted material which now
includes relatively clean grains of particulate matter and the
lighter in weight coating material which is knocked off or
separated from base matter.
As best shown in FIG. 5, the outer, open ends of the discharge
tubes 85 are adjacent the outer surface of the cylindrical
deflector shells 72. From the foregoing it will be seen that the
individual granules of particulate matter flowing upwardly in the
lift tube units 30 are impacted against one another again and
again. Moreover, repeated impacts occur as the matter enters the
lower inlet rings 64 on the lift tubes 62 as well as during the
upward flow in the tubes. Further impacts occur as the matter
strikes the pad of material formed at the closed upper end of the
lift tube extension 74. Moreover, a further impact zone is
developed adjacent to the mouth of the discharge tube 85 where the
downwardly rebounding material collides with the upwardly moving
matter before it moves outwardly toward the outer end of the
discharge tubes.
As best shown in FIGS. 1 and 2 when all four of the deflector
assemblies 70 of the respective lift tube scrubber units 30 are
arranged with the discharge tubes 85 directed radially inwardly
toward the center of the housing 12, an intense, impact scrubbing
zone is formed in center of the housing section 22. The heavier
particles of material that are discharged from the tubes 85 in a
horizontal direction as shown by the arrows A gravitate downwardly
onto a conical structure 86 centered above the air plenum chamber
32. The sloping surfaces of the cone 86 direct the material
outwardly toward the circular openings 28a in the wall 28 and the
material then flows downwardly into the shells 36 of the respective
scrubber units 30 to be recycled in the scrubbing process. The
impact scrubbing zone centered above the cone 86 may be formed by
the impingement of moving material streams impacting one another
from opposite directions as described and set forth in the
foregoing copending United States patent application, or in the
alternative, a removable target structure 88 may be provided. The
target structure includes pairs vertically extending impact vanes
90 which are secured along their inner vertical edges to a central
hollow tube 92. The tube 92 is adapted to be restrained by
upstanding support stud 94 which is secured to the apex of the cone
86. For lifting the target from the stud a handle 96 is provided at
the upper end of the tube 92.
As shown in FIGS. 1 and 2 when the discharge tubes 85 are directed
radially inwardly the flow of material (arrows A) strikes the
convergent surfaces of the impact vane 90 and the collisions of
particles with the vane surfaces causes another intense scrubbing
zone to develop immediately above the cone 86. In this region
additional coating materials remaining on the grains are knocked
off and removed by the repeated impacts. The heavier grains of
particulate matter gravitate downwardly onto the sloping surfaces
of the cone 86, and are directed into the shells 36 of the
respective scrubber units 30 through the openings 28a in the wall
28. In this manner the particulate matter being handled by the
scrubber 10 is continuously recycled through the individual lift
tube scrubber units 30 for a selected period of time until the
desired degree of cleaning action is obtained.
Each individual deflector 70 is supported by a rod 82 and each rod
is provided with an enlarged head 84 at the lower end. The
deflectors are rotatable from the normal operational position of
FIG. 2 to the discharge position of FIG. 3 wherein the discharge
tubes 85 are directed radially outwardly away from the center of
the housing 12. Each support rod is keyed to its deflector for
rotation therewith by a cross pin 98 (FIG. 5) which extends through
slots 74a provided on diametrically opposite sides of the lift tube
extension 74 at the upper end as shown in FIG. 5. When the support
rods 82 are rotated 180.degree. from the position shown in FIG. 2,
the discharge tubes 85 of the respective deflectors 70 will be
rotated a like amount to direct the discharge of material outwardly
as shown in FIG. 3 by the arrows A.
With the deflectors 70 positioned in the discharge position as
shown in FIG. 3 the fluidized stream of particulate matter and
coating materials separated therefrom are directed outwardly
through the housing wall into a plurality of separate discharge
boxes secured to the outer surface of the housing 12 and referred
to generally by the reference numeral 100. Each discharge box is
positioned adjacent an elongated vertical slot 102 formed in the
wall of the scrubber housing 12 and aligned with the outlet end of
the discharge tubes 85 when the deflector assemblies 70 are in the
discharge position as shown in FIG. 3. As best shown in FIG. 1, the
slots 102 are longer in vertical dimension than the diameter of the
discharge tubes 85 and the vertical adjustment of the lift tubes
provided to vary the distance D changes the level of the
discharging streams issuing from the outlet ends of the discharge
tubes 85 into the respective discharge boxes 100. The slots 102 are
slightly larger in width or horizontal dimension than the outside
diameter of the discharge tubes 85 so the precision alignment is
not required when rotating the deflector assemblies 70 into the
discharge position as shown in FIG. 3.
Each of the discharge boxes 100 includes a pair of opposite side
walls 104, an outside wall 106, a top wall 108 and a bottom wall
110 and the outer wall of the intermediate section 22 of the
scrubber housing 12 provides an inside wall for the discharge
boxes. In order to protect the outer side walls 106 of the
discharge boxes from excessive wear and abrasion from the
discharging materials of the discharge tubes 85 and further to
provide a secondary impact zone for separation of the lighter
weight coating materials from the base particulate matter, each
discharge box is provided with a relatively thick, heavy, hanging
baffle 112 formed of resilient material such as rubber and the like
and extending downwardly through a slot formed in the top wall 108.
The baffles hang freely and are positioned directly in front of the
discharging streams from the discharge tubes 85. Each hanging
baffle includes an enlarge bulbous upper end portion for supporting
the baffle from the top wall of the discharge box and the lower end
portion of the baffle is free to swing and may be deflected by the
high velocity stream of material impinging thereon. Within each
discharge box 102 there is provided a pair of adjustable baffles
114 and 116 supported on shafts rotatably controllable from the
outside of the boxes to achieve desired slopes for directing the
heavier, cleaned sand grains or other particulate matter downwardly
towards the lower end wall 110. A fixed baffle 118 is also provided
to guide the downwardly flowing material as it drops from the
hanging resilient baffle 112 onto the adjustable baffle 114. The
material sifts downwardly in a falling stream or curtain from the
lower edges of the baffles as it moves toward the lower end of the
boxes. The thickness of the streams of material is controlled by
the adjustable baffles. Material reaching the bottom wall 110 flows
through a bottom discharge outlet 110a via a short pipe section 122
into the upper end of a pinch valve 120. The lower end of the pinch
valves 120 maybe interconnected to a common discharge manifold 124
so that the cleaned particulate matter from the scrubber 10 may be
discharged or transported via a pneumatic transport system or the
like such as that shown in U.S. Pat. No. 3,297,366. The pinch
valves 120 may be of the type shown in this patent and are normally
closed until a sufficient amount or head of material has been
collected in the upper portion of the valve housing. The flexible
sleeves then open to discharge the material into the pneumatic
transport system. The valves may also be positively controlled to
open and close.
In order to separate the lighter in weight coating materials
removed from the grains or base particles of the particulate matter
being treated, each discharge box 100 is provided with an
atmospheric damper assembly 122 which permits air to enter the
lower end of the discharge box through an opening 104a in one of
the side walls spaced below the fixed baffle 118 as best shown in
FIG. 1. Air entering through the dampers 122 passes upwardly in a
tortuous path moving upwardly through the downwardly flowing
curtain of material discharged from the lower edges of the
respective baffles 114, 116 and 118. This upwardly moving draft of
air current carries the lighter weight materials upwardly to
discharge outlets 128 formed on the upper walls 108. The discharge
outlets 128 on the top walls 108 of the discharge boxes 100 are
connected to a suction manifold 130 and a discharge fan 132 is
provided to provide the necessary draft for removal of the fine
materials as shown in FIGS. 1, 2 and 3. The amount of fines removed
can be controlled by adjusting the negative pressure in the
discharge boxes. It will thus be seen that the baffles 112 in
discharge boxes 100 provide yet another impact zone and the air
draft therein provides means for separating the cleaned sand grains
from the lighter weight coating materials that is knocked off of
base particulate matter. The cleaned sand is collected in the lower
end of the discharge boxes 100 for delivery by a suitable transport
system or the like to another location for further use.
In accordance with an important feature of the present invention,
as previously described, the lift tube 62, ring 64 and deflector
assembly 70 of each individual scrubber unit 30 is supported by an
individual elongated support rod 82 having an enlarged head 84 at
the lower end. The rods project upwardly through openings 24a in
the circular wall 24 (FIG. 5) into the upper portion of the housing
adjacent the level of the hopper 16. Each support rod 82 is keyed
to a lift tube extension 74 by means of a cross pin 98 so that
rotation of a support rod will cause the deflector assembly 70 to
rotate therewith.. Rotation of all of the support rods 82 by
180.degree. from the position of FIG. 2 causes the discharge
assemblies 70 to rotate in unison until the discharge tubes 85 are
directed outwardly in the discharge position as shown in FIG. 3. In
order to limit and control the amount of rotation, of the discharge
assemblies 70 at least one shell 72 is provided with a pair of
upstanding limit stops 134 and 136 secured to the inside surface as
best shown in FIGS. 1, 2 and 3. In order to control the flow of
sand or other particulate matter into the scrubber from the
discharge opening 20 of the hopper 16, there is provided a conical
valve member 138 adapted to open and close the discharge opening to
regulate the flow. The conical valve member 138 is mounted on the
outer end of a cylinder rod 140a of a vertically positioned, fluid
operated valve cylinder 140. The lower end of the cylinder 140 is
supported on a channel-like base 142 positioned in the intermediate
housing section 22 and supported from the upper circular wall 24 at
opposite ends by depending brackets 144 as best shown in FIG. 1. As
shown in FIGS. 2 and 3, opposite side edges of the support channel
structure 142 cooperate with the upstanding limit stops 134 and 136
on the right hand (FIG. 1) deflector assembly 70 to provide for
alignment of the discharge tubes 85 of the respective deflector
assembly in the normal operating position (FIG. 2) or the discharge
position (FIG. 3).
Referring now more particularly to FIG. 5, the support rods 82 of
the respective deflectors 70 are connected by turnbuckles 83 with
upper ends 87 which extend upwardly through the openings 24a in the
circular wall 24. The upper end portion of each upper rod is
slidably disposed in a pair of flanged bearings 146 spaced on
opposite sides of a chain sprocket 148, which is secured by set
screws 150 to a sleeve 151 attached to the support rods 87 by a
removable pin 153. The lower flanged bearing 146 is attached to the
upper surface of the circular wall 24 and the upper flanged bearing
is attached to the upper surface of a circular support plate 152
supported in parallel, spaced apart relation above the circular
wall 24 by a plurality of support post assemblies 154. An endless
roller chain 156 is entrained around all of the several sprockets
148 in order to drivingly rotate all of the support shafts 82 in
unison and thereby rotate all of the deflector assemblies 70 when
it is desired to move the deflectors from a discharge to an
operating position or vice versa.
As shown in FIG. 4, the roller chain 156 is passed around all of
the sprockets 148 of the respective support rods 82 and in
addition, the chain is passed around a pair of idler sprockets 156
into driving engagement with a single drive sprocket on the output
shaft of a fluid motor 160. The fluid motor 160 is reversible and
is supplied from a source of compressed fluid. A valve system is
used to operate the motor in reverse directions in order to rotate
the deflector assemblies 70 back and forth between the normal
operating position and the discharge position of FIGS. 2 and 3.
Normally the fluid motor is actuated to rotate the sprocket 158 in
a given direction for a selected time interval, which interval is
slightly longer than the time required to rotate the deflector
assemblies through 180.degree. from one position to the other.
Rotation of the deflectors is stopped by engagement of one or the
other stop members 134 or 136 with the side of the support channel
142 as previously described.
When it is desired to adjust the spacing distance D between the
upper end of the nozzle 42 and its respective entrance ring 64 on
the lift tube 62, the set screw 150 on the sprocket 148 is loosened
and the support rod is moved up or down as desired to provide the
proper spacing D. After the spacing is set the set screw 150 is
retightened to again key the sprocket to the support rod.
The scrubber 10 provides means for adjusting the individual
clearance distance D between the lift tube entrance ring and the
nozzle in each of the scrubber units 30 and in addition the system
provides for simultaneously rotating all of the deflector
assemblies 70 of the respective scrubber units to the normal
operating or the discharge position as desired.
As shown in FIG. 1, relatively large access slots 162 are provided
in the housing wall 12 so that the chain, sprockets, bearings and
set screws may be serviced and adjusted as described. In addition,
as shown in FIGS. 2 and 3 the intermediate section 22 of the
housing 12 is formed with relatively large access openings 164 in
the side wall in order to permit servicing or replacement of the
individual deflector assemblies 70. These may be removed completely
from the housing 12 by detachment from the respective lift tubes 62
when the couplings 76 and the set screws 150 are loosened. The
access openings 162 are large enough in width and height to permit
easy service or complete withdrawal of a deflector assembly 70.
During normal operation, arcuate cover plates 164 are provided to
cover the access openings 162 and confine the particulate material
and dust within the intermediate section 22 of the housing 12.
Although the present invention has been described with reference to
a single illustrative embodiment thereof, it should be understood
that numerous other modifications and embodiments can be devised by
those skilled in the art that will fall within the spirit and scope
of the principles of this invention.
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