US3762656A

US3762656A - Shakeout and crushing apparatus

Info

Publication number: US3762656A
Application number: US00197062A
Authority: US
Inventors: V Deve
Original assignee: Combustion Engineering Inc
Current assignee: Combustion Engineering Inc
Priority date: 1971-11-09
Filing date: 1971-11-09
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02
Also published as: CA993623A; GB1397259A; IT970275B; FR2159373A1

Abstract

A shakeout and crushing apparatus for reducing foundry sand to a condition for classification and reuse. The device comprises a shakeout chamber which is caused to orbitally vibrate. The chamber has an upper shakeout deck, a second disintegration deck supporting a plurality of metal balls, and a third wire screen deck. The sand is successively passed and progressively classified through the three decks. Material remaining on the wire screen deck is recycled to a disintegration chamber on the second deck which assures crushing of friable material and the removal of any tramp metal which may be present in the sand.

Description

United States Patent 1 [111 3,762,656

Deve Oct. 2, 1973 154] SHAKEOUT AND CRUSHING APPARATUS 979,635 12/1910 Mumford 241/84 11X 5 5 z [75] Inventor: Vagn Deve, Pittsburgh, Pa. 76746 I 24mm UX 1 1 Assigneei Combustion Engineering Primary Examiner Donald G. Kelly W COfln- A!t0rneyEldon H. Luther et al.

122] Filed: Nov. 9, 19711 21 Appl. No.: 197,062 1571 ABSTRACT A shakeout and crushing apparatus for reducing foundry sand to a condition for classification and reuse. [52] Cl f gg g i g g g The device comprises a shakeout chamber which is [51] Int Cl 302C caused to orbitally vibrate. The chamber has an upper [58] Field R 60 8] shakeout deck, a second disintegration deck supporting 241/76 77 I75 a plurality of metal balls, and a third wire screen deck.

4 d The sand is successively passed and progressively classified through the three decks. Material remaining on the wire screen deck is recycled! to a disintegration [56] References Cited chamber on the second deck which assures crushing of UNITED STATES PATENTS friable material and the removal of any tramp metal 1,293,188 Pfersch X be present in the and 1 1,669,686 5/1928 Worthington. 241/84 X 1,286,389 l2/l9l8 Mullen 24l/84 UX 13 Claims, 3 Drawing, Figures 3a 3a [1 40 40m SHAKEOUT AND CRUSHING APPARATUS BACKGROUND OF THE INVENTION The high production level of modern foundries requires sophisticated facilities capable of keeping up with desired output. This high production results in the use of great quantities of sand (on the order of IO 100 tons per hour). Due to initial cost considerations and the ecological concern over depletion of raw materials, reclamation and reuse of the foundry sand has become of increasing desirability.

Such sand reclamation has been accomplished in high production foundries by processing castings through a vibratory shakeout unit where the frequency and amplitude of the vibration is designed to break off the sand mold and knock off the cores. The rejects including pieces of metal and lumps of bonded sand are passed along a conveyor belt through the field of a magnetic separator to remove tramp metal. The remaining material is passed to a cage mill where it is broken down to substantially original size for screening and classification for reuse.

This sand reclamation process is necessarily complicated and expensive and has not proven economical for reclamation in foundries having lower production levels where reclamation would otherwise also be desirable. Additionally, in casting of non-magnetic materials such as stainless steel, aluminum or brass, thisprocess has some drawbacks in that the removal of tramp metal is difficult, and any metal which enters the cage mill could prove damaging to the interior mill surfaces.

SUMMARY OF THE INVENTION There is therefore herein provided a novel shakeout and crushing apparatus for reducing foundry sand to a condition for classification and reuse which is economically feasible for use at low production levels and which assures removal of tramp metal from the sand. The device comprises a shakeout chamber which is caused to orbitally vibrate. The chamber provides progressive classification by means of a porous upper shakeout deck having large holes extending therethrough. Below the shakeout deck is a porous second deck having relatively smaller holes and supporting a plurality of metal balls, which due to the vibratory action bounce about to crush any material which falls to the second deck.

Tramp metal of larger size than the small holes in the second deck will be trapped at this level to assist in the crushing action of the balls. The trapped metal and any large uncrushable sand lumps may be periodically removed through a cleanout door provided in the chamber at this level.

Beneath the second deck is a third deck which is comprised of a wire screen for receiving crushed material passed through the second deck, and which in turn will allow only fine sand to pass therethrough to the shakeout chamber floor for removal to a sand classifier and storage for reuse. The material remaining on the wire screen is recycled to a disintegration chamber on the second deck. The disintegration chamber will crush any friable material delivered thereto and trap any tramp metal and unbroken sand lumps (which have passed through the second deck) for periodic removal while permitting sand below a certain size but above the size of the screen mesh to be recycled to the second deck.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the shakeout and crushing apparatus of this invention.

FIG. 2 is an end view of the shakeout and crushing apparatus along line 22 of FIG. 1.

FIG. 3 is a side elevational view in section of the shakeout chamber along line 33 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIGS. 1 and 2 show the overall arrangement of the shakeout and crushing apparatus 10 for reducing foundry sand to a condition for classification and reuse. A support base 12 constructedof a series of I-beams supports a plurality of vibration isolating springs 14. The springs 14 engage extensions 16 fixed to a shakeout chamber 18. Also supported by the base 12 is a vibratory drive motor carriage 20 which in turn supports a motor guide 22. A motor support base 24 is movably carried in the guide 22 and has a vibratory drive motor 26 mounted thereon. The motor 26 rotates a pulley 28 to drive the drive belt 30 which in turn rotates a pulley 32 rotatably fixed to the shakeout chamber 18. The pulley 32 may be of the eccentric weight type so as to cause orbital vibration of the shakeout chamber 18 upon rotation thereof. A protective housing 34 is connected to the chamber 18 so as to prevent debris from damaging or interfering with the vibratory drive mechanism.

Within the shakeout chamber 118 there is an upper shakeout deck 36 for receiving molds with castings (see FIG. 3). The shakeout deck 36 has vertical scalping bars 38 mounted thereon and large holes 40 extending therethrough, the holes being on the order of 2 to 3 inches in diameter. Beneath the shakeout deck 36 is a second deck 42 having a series of holes 44 therethrough, the holes being of somewhat smaller size than the holes 40 of the upper deck 36 (for example onehalf inch in diameter). The second deck 42 supports a plurality of metal balls 46 which assist in the crushing of the foundry sand when the shakeout chamber 18 is orbitally vibrated.

At one end of the shakeout chamber 18 adjacent the level of the second deck 42 there is provided a cleanout door 48 which may be periodically opened to remove material from the second deck level which is unable to pass therethrough, such as tramp metal or lumps of bonded sand. At the opposite end of the shakeout chamber 18 adjacent the level of the second deck42 is located an oversize return chute 50 which communicates with a disintegration chamber 52 within the shakeout chamber 18 through an opening 54 in the wall of the shakeout chamber. The disintegration. chamber 52 has an upper wall 56 which overlies a floor portion 58, the floor portion 58 being an extension of the second deck 42 without the holes 44 therein. The top wall 56 terminates above the floor 58 such that an opening 60 is provided therebetween, the opening 60 being somewhat smaller than the diameter of the holes 44. The disintegration chamber 52 has rods 62 extending therethrough so as to assist in the disintegration of the material returned to the chamber .52. A cleanout door 64 is provided in the return chute 50 so as to enable periodic cleanout of material trapped in the disintegration chamber 52.

Beneath the second deck 42 there is provided a third deck comprising a wire mesh screen 66 which is oriented so as to have an inclined angle with respect to the horizontal axis of the shakeout chamber 18. The lower end of the wire screen 66 terminates adjacent an opening 68 in the side of the chamber l8. An oversize return discharge spout 70 is located adjacent the opening 68 so as to receive any oversize material trapped above the screen 66. Beneath the wire screen 66 is a shakeout chamber floor 72 which is similarly inclined with respect to the shakeout chamber 18. The floor 72 terminates adjacent an opening 7 3 in the wall of the chamber 18 so as to permit screened sand to discharge through the opening 74 into a screened sand discharge spout 76. In order to eliminate dust within the chamber 18 which is created during the vibration thereof, an exhaust conduit 78 communicates with the interior of the chamber and is connected to a suitable vacuum source so as to evacuate the dust therefrom.

An oversize return elevator 80 is provided to recycle oversize material trapped on the wire screen 66. The oversize elevator 80 has a receptacle 82 which receives material from the discharge spout 70. A fan means 86 is supported on the elevator 80 to draw the material upwardly to a discharge 84 into the return chute 50 of the shakeout chamber 18. The screened sand from the shakeout chamber floor 72 is passed to a sand classifier (not shown) by means of a screened sand elevator 88 for classification and storage for reuse. The elevator 88 has a receptacle 90 for receiving screened sand from the discharge spout 76. A fan means 94 is supported on the elevator 88 to draw the material upwardly to a discharge 92 into the classifier.

With the shakeout and crushing apparatus 10 thus described, the operation thereof is as follows. The position of the vibratory drive motor base 24 is adjusted so as to provide the proper tension on the drive belt 30, and the motor 26 is then actuated to provide an orbital vibrating movement to the chamber 18 on the base 12 through the springs 14 through rotation of the eccentric weight pulley 32. A number of molds are placed in the shakeout chamber 18 on the upper shakeout deck 36. The scalping bars 38 will assist in the breaking off from the castings of burnt on sand, gates and risers under the vibratory action of the chamber 18. The friable material and some tramp metal will fall through the large holes 40 in the deck 36 to the deck 42. Due to the orbital vibration of the chamber 18 the metal balls 46 will be in continuous motion so as to impact the material on the deck 42 breaking it into smaller sizes so that the majority of the sand and even some of the tramp metal will pass through the small holes 44 in the deck 42. Any tramp metal which is of such a size so as to be unable to pass through the holes 44 will serve to assist in the breaking up of the foundry sand lumps due to the vibration imparted thereto. The vibratory action of the chamber 18 is typically on the order to 900 cycles per minute so that each ball (or piece of tramp metal) has the effect of creating a hammer action approximately 900 times during each minute. Periodically the cleanout door 48 may be opened to remove the metal and sand lumps which accumulate on the deck 42.

The material which passes through the second deck 42 falls onto the wire screen 66 of the third deck which may be typically of a screen mesh size 20. The wire screen 66 sifts the sand so as to pass only the grains below this size to the shakeout chamber floor 72. The

slope of the wire screen 66 and floor 72, in conjunction with the orbital vibration of the chamber 18, causes both the oversize particles and the screened sand to migrate to the lower ends thereof for discharge through the respective openings 68 and 74 into the discharge spouts and 76. The screened sand from the discharge spout 76 will be removed to a sand classifier for storage and reuse by means of the sand elevator 88.

The oversize material trapped on the screen 66 and passed through the discharge spout 70 will be returned to the return chute 50 by means of the oversize return elevator 80. The oversize material returned will enter the disintegration chamber 52. Due to the orbital vibration of the chamber 18, material within the disintegration chamber 52 will be impacted by the rods 62 so as to further reduce the size thereof. Friable material within this chamber 52 which is reduced in size will migrate through the opening 60 back onto the second deck 42 for passage therethrough to the wire screen 66. Tramp metal and larger unbreakable sand lumps will remain in the disintegration chamber and will be periodically removed through the cleanout door 64. As noted above, dust particles which would necessarily be accompanied by the rapid orbital vibration of the chamber 18 are controlled by the provision of an exhaust conduit 78 which is connected to suitable dust collection equipment for removal thereof.

From the foregoing it is apparent that there is herein provided a simple shakeout and crushing apparatus which is economical for use at low production levels and which will remove tramp metal from the foundry sand being reclaimed. The apparatus comprises a shakeout chamber which is caused to orbitally vibrate. The chamber has an upper shakeout deck, a second deck supporting a plurality of metal balls and a third wire screen deck through which the sand is successively passed and progressively classified. The metal balls on the second deck, under the influence of the orbital vi bration of the shakeout chamber, serve as rapidly acting hammer means. Material which fails to pass through the wire screen is recycled to a disintegration chamber on the second deck which further assures the removal of any tramp metal of bonded sand lumps which may be present in the sand being reclaimed to crush material on the deck so that it will pass therethrough to the wire screen.

While this preferred embodiment of the invention has been shown and described, it will be understood that it is merely illustrative and that changes may be made without departing from the scope of the invention as claimed.

What is claimed is:

R. A shakeout and crushing apparatus for reclamation of foundry sand comprising: a base, vibration isolative means mounted on said base for protecting said base from external vibrations, a shakeout chamber supported on said base by said vibration isolative means, said chamber having a porous upper deck, a porous second deck and a porous third deck of progressively more limited porosity, a plurality of hammer means carried by said second deck to accomplish crushing of the sand on said deck, means for removing material trapped on said second deck, a first conduit adjacent said third deck and communicating therewith to receive material trapped on said third deck, a second conduit adjacent the bottom of said shakeout chamber to receive sand passed thereto, a recycle and disintegration chamber adjacent to and communicating with said second deck, means for recycling said trapped material from said first conduit to said recycle and disinte gration chamber, and a drive means for imparting an orbital vibration to said shakeout chamber.

2. The apparatus of claim ll wherein said vibration isolative means are comprised of a series of coil springs.

3. The apparatus of claim 2 wherein said third deck is comprised of a wire screen oriented so as to be angled with respect to the horizontal axis of said shakeout chamber.

4. The apparatus of claim 3 wherein said porous upper deck is comprised of a flat plate having a plurality of large openings and a series of scalping bars extending upwardly from said plate, and wherein said sec' ond deck is comprised of a flat plate having a series of openings substantially smaller than the openings of said plate of said upper deck.

5. The apparatus of claim 4 wherein said hammer means comprises a plurality of metal balls substantially covering the area of said second deck.

6. The apparatus of claim 5 wherein said recycle and disintegration chamber includes a non-porous extension of said second deck flat plate forming a floor portion therefor, an upper wall overlying said floor portion and terminating at one end above said floor portion so as to form an opening therebetween, said opening between said upper wall and said floor portion being of a size less than said openings in said second deck, a plurality of rods positioned between said upper wall and said floor portion, and a return chute communicating with the interior of said recycle and disintegration chamber to permit passage of recycled material thereinto.

7. The apparatus of claim 6 wherein said drive means includes a platform fixed to said base, a drive motor adjustably positionable on said platform, an eccentric weight pulley rotatably mounted on said shakeout chamber, and a belt means connecting said motor to said eccentric weight pulley in order to impart rotation thereto.

8. The apparatus of claim '7 wherein said shakeout and crushing apparatus further includes an exhaust system communicating with the interior of said shakeout chamber so as to remove dust therefrom.

9. An apparatus for crushing and classification of a friable material comprising: a chamber; means for imparting orbital vibration to said chamber; progressive classification means within said chamber for progressively classifying said friable material as it is passed through said chamber, said progressive classification means including a first porous deck having a series of holes therein and a plurality of scalping bars extending upwardly therefrom, a second porous deck having a se ries of holes therein of substantially smaller size than said holes of said first deck, and a third deck comprised of a wire screen angled with respect to the horizontal axis of said chamber; means for providing an auxiliary crushing action to said material at one level of classification; first removing means for removing and recycling within said progressive classification means crushed material trapped above the desired final level of classification; and second removing means for removing said friable material which has been processed to a desired level of classification for storage and reuse.

110. The apparatus of claim 9 wherein said means for providing auxiliary crushing action includes a hammer means located on said second deck and a recycle and disintegration chamber in juxtaposition with said second deck.

11. The apparatus of claim 10 wherein said hammer means includes a plurality of metal balls.

12. The apparatus of claim 11 wherein said recycle and disintegration chamber includes a non-porous extension of said second deck flat plate forming a floor portion therefor, an upper wall overlying said floor portion and terminating at one end above said floor portion so as to form an opening therebetween, said opening between said upper wall and said floor portion being of a size less than said openings in said second deck, a plurality of rods positioned] between said upper wall and said floor portion, and a return chute comm unicating with the interior of said recycle and disintegration chamber to permit passage of recycled material thereinto.

113. The apparatus of claim 12 wherein there is further included an exhaust system communicating with the interior of said vibrating chamber so as to remove dust therefrom.

Claims

1. A shakeout and crushing apparatus for reclamation of foundry sand comprising: a base, vibration isolative means mounted on said base for protecting said base from external vibrations, a shakeout chamber supported on said base by said vibration isolative means, said chamber having a porous upper deck, a porous second deck and a porous third deck of progressively more limited porosity, a plurality of hammer means carried by said second deck to accomplish crushing of the sand on said deck, means for removing material trapped on said second deck, a first conduit adjacent said third deck and communicating therewith to receive material trapped on said third deck, a second conduit adjacent the bottom of said shakeout chamber to receive sand passed thereto, a recycle and disintegration chamber adjacent to and communicating with said second deck, means for recycling said trapped material from said first conduit to said recycle and disintegration chamber, and a drive means for imparting an orbital vibration to said shakeout chamber.

2. The apparatus of claim 1 wherein said vibration isolative means are comprised of a series of coil springs.

4. The apparatus of claim 3 wherein said porous upper deck is comprised of a flat plate having a plurality of large openings and a series of scalping bars extending upwardly from said plate, and wherein said second deck is comprised of a flat plate having a series of openings substantially smaller than the openings of said plate of said upper deck.

8. The apparatus of claim 7 wherein said shakeout and crushing apparatus further includes an exhaust system communicating with the interior of said shakeout chamber so as to remove dust therefrom.

9. An apparatus for crushing and classification of a friable material comprising: a chamber; means for imparting orbital vibration to said chamber; progressive classification means within said chamber for progressively classifying said friable material as it is passed through said chamber, said progressive classification means including a first porous deck having a series of holes therein and a plurality of scalping bars extending upwardly therefrom, a second porous deck having a series of holes therein of substantially smaller size than said holes of said first deck, and a third deck comprised of a wire screen angled with respect to the horizontal axis of said chamber; means for providing an auxiliary crushing action to said material at one level of classification; first removing means for removing and recycling within said progressive classification means crushed material trapped above the desired final level of classification; and second removing means for removing said friable material which has been processed to a desired level of classification for storage and reuse.

10. The apparatus of claim 9 wherein said means for providing auxiliary crushing action includes a hammer means located on said second deck and a recycle and disintegration chamber in juxtaposition with said second deck.

12. The apparatus of claim 11 wherein said recycle and disintegration chamber includes a non-porous extension of said second deck flat plate forming a floor portion therefor, an upper wall overlying said floor portion and terminating at one end above said floor portion so as to form an opening therebetween, said opening between said upper wall and said floor portion being of a size less than said openings in said second deck, a plurality of rods positioned between said upper wall and said floor portion, and a return chute communicating with the interior of said recycle and disintegration chamber to permit passage of recycled material thereinto.

13. The apparatus of claim 12 wherein there is further included an exhaust system communicating with the interior of said vibrating chamber so as to remove dust therefrom.