US2771189A - Work blasting apparatus - Google Patents

Description

Nov. 20, 1956 A. J. KRIZ 2,771,189

WORK BLASTING APPARATUS Filed Nov. 8, 1952 I e- Sheets-Sheet 1 Fi i INVENTOR. ADOLPH J. KRIZ HIS ATTO RNEYS Nov. 20, 1956 A. J. KRIZ 2,771,189

WORK BLASTING APPARATUS Filed Nov. 8, 1952 6 Sheets-Sheet 2 INVENTOR. ADOLPH J. KRIZ Hi5 ATTORNEYS Nov. 20, 1956 A. J. KRIZ WORK BLASTING APPARATUS 6 Sheets-Sheet 3 Filed Nov. 8, 1952 105 3&3 97

INVENTOR. ADOLPH a, KRIZ BYMMQ? HIS ATTO R NEYS Nov. 20, 1956 A. J; KRlZ 2,771,189

WORK BLASTING APPARATUS Filed Nov. 8, 1952 6 Sheets-Sheet 4 INVENTOR. ADOLPH J. KRIZ.

HIS AT TO RN EYS 6 Sheets-Sheet 5 Filed NOV. 8, 1952 INVENTOR.

, 93 Nov BYCZ HIS ATTORN EYS Nov. 20, 1956 A. J. KRlZ 2,771,189

WORK BLASTING APPARATUS Filed Nov. 8, 1952 6 Sheets-Sheet 6 5 I E 8 250 5 I J 4 6 224 N IIIIII'IIIIIII INVENTOR. ADOLPH J. KRIZ HIS ATTORNEYS United States Patent WORK BLASTNG APPARATUS Adolph J. Kriz, Hagerstown, Md., assignor to Pangborn Corporation, Hagerstown, Md., a corporation of Maryland Application November 8, 1952, Serial No. 319,550

4 Claims. (Cl. 209-21) The present invention relates to apparatus for subjecting work articles to the action of .a stream of projected particles for the purpose of cleaning, abrading, peening or otherwise working the surfaces of the articles.

With such apparatus economy dictates that themejected blastant particles should be collected and recycled for further projecting passes. However, the impingement of the particles on the work articles loosens and removes foreign materials and/ or portions of the surface from the work articles, and such materials are collected with the projected particles and interfere with their reuse.

In the past, various types of arrangements have been used,

to separate out the undesired materials, but have not been too satisfactory. Their most serious difiiculty has been a need for frequent supervision and maintenance.

Among the objects of the present invention is the provision of a novel arrangement for recycling blastant par.- ticles in a work blasting apparatus, by which arrangement the above and related disadvantages are minimized.

This as well as additional objects of the present invention will be more completely understood from the following description of several of its exemplifications,.reference. being made to the accompanying drawings wherein:

Fig. l is a side view'of the essential elements of a work blasting apparatus incorporating the present invention, parts being broken away to better show some of the details;

Fig. 2 is a sidevview of the apparatus of Fig. 1 looking from the right-hand side of that figure;

Fig. 3 is an enlarged detail view showing one portion of the blastant recycling arrangement;

Fig. 4' is a side view of the apparatus of Fig. 3 taken from the left-hand side of that figure;

Fig. 5 is a front view showing another portion of the recycling arrangement of Fig. 1; and

Fig. 6 is a vertical sectional view of the apparatus, of Fig. 5, taken along the line 66.

According to the present invention, a work blasting apparatus is provided with a blastant recyclingmechanism having a first scalping drum assembly connected to automatically separate out articles, such as core Wires, that are coarser than the blastant particles, as, these particles :are collected for recycling, and a second scalping drum assembly connected to automatically remove from the scalped blastant substantially all articles larger than the blastant particles and to also remove substantially all fines.

According to a preferred form of the invention, the first scalping drum assembly is at a low level, the second scalping drum assembly is at a high level, an elevator mechanism lifts the recycling blastant from the low level to the high level, and fines-separation structure is provided by having the second scalping drum assembly connected to drop the recycling blastant particles, distributed in the form of a long thin curtain, through an air stream conduit. A particularly eflfective construction "ice uses a multiplicity of blastant-projecting units, each have ing a blastant supply conduit connected to collect recycling blastant from different longitudinal portions of the dropping curtain.

Although the present invention is suitable for use in, connection with many different kinds of work blasting apparatus, Figs. 1 to 6 inclusive illustrate it in combination with a cylinder block cleaning apparatus of the type described in Huyett Patent No. 2,510,927, granted June 6, 1950. In general, the combination includes an en.- closure or room 10 having Walls, one of which shown at 12 in Fig. 2 carries a multiplicity of blasting units 20. Room 10 has a floor 14 which is positioned over anexcavation as by means of beams 16, 18.

The room It is shaped so as to provide a path through which work pieces are carried as by means of overhead rail 30, as well as bottom rail 31, if desired. A doorway 34 having a wide central portion 36 and narrower upper andlower extensions 38 permits the work pieces to enter and leave the room 10. Suspended from the upper rail 30 is a traveling work holder 40 which may be provided with arms, 42 upon which the work articles can be.

mounted and from which they can be removed. Such a. work piece is illustrated at 44 in Fig. 1.

The top of the room 10 is provided with a slotthrough which the hanger 40 projects and moves :as it carries the.

work pieces in the path of the blasting-projecting,units 20. This slot can be provided with a vertically extending bafile 48 to reduce the escape of blastant particles. The

door 34 can also be provided with curtains such as strips; of rubber or other flexible material fastened at one end.

blastant supply conduit 50. The floor 14, which can beentirely eliminted, is of perforated form such as a grating, to permit blastant particles, :after they have been projected' against work articles, to drop through into a collection trough 60. At the bottom of this trough, a conveyor or other advancing mechanism is arranged to carry the collected articles over to a centralized location. In the form shown, a vibrating type conveyor 62 operated as by vibrating mechanism 64 elfects such transfer.

Conveyor 62 discharges directly into the rotating drum 104. of a scalping drum assembly 100, where coarser articles are moved through and drop off discharge chute 102 while blastant particles drop through perforations in the wall of the drum and fall through hopper 106 into a. collecting boot 168 of a bucket elevator 110. The details of one highly ellective form of scalping drum are shown in Figs. 3 .and 4. Such a drum will sift out such things as core wires and the like that may be contained in the work piece 44. These sifted out pieces drop from. chute 102 onto a lifting conveyor belt 114 which carries them to a point Where they can be unloaded for disposal or reuse.

At the upper end of elevator 110, upper chute 116 collects the blastant particles passed by the scalping drum assembly 100, and delivers them to a second scalping drum assembly 200. Here the particles are subjected to, a second scalping or sifting operation which removes substantially :all material coarser than the particles. At the same time, the very fine material such as sand, fragmented pieces of the blastant particles, etc., which accompany the particles to be reused, are also separated.

The desired particles then drop into a feed hopper 210 from which a plurality of feed chutes 221, 223 and 225 connect individual blastant feed conduits 50.

Coarser material separated by scalping drum assembly 200 is dropped into refuse conduit 202. Fines are separated out into a collecting hopper 230 from which they can be removed as by discharge duct 234.

For operation in conjunction with a multiplicity of blastant-projecting units, it is advisable to use a relatively long second scalping drum assembly, or to use two shorter assemblies as indicated in Fig. 2. An additional second scalping drum assembly is there shown at 201 arranged symmetrically with assembly 200, and connected to deliver recycled blastant into the same feed hopper 210. As shown, the coarse refuse duct 202 is common to both second scalping drum assemblies, but an additional fines discharge duct 235 is provided.

, Addition of fresh blastant can be made in any desired manner. For convenient operation, collecting trough 60 is provided with a loading hopper 66, the top of which can be at or about the level of floor 14, a passageway 68 providing the desired communication. Additional feed hopper 70 can be similarly provided under the outlet door of room to collect and return blastant particles that might make their way through the doorway. Inasmuch as this doorway is relatively close to the active blasting zone, there is likely to be appreciable leakage of blastant through the outlet door, particularly when a work article is passing through this doorway. Either or both hoppers 66, 70 can have their upper openings covered, as by a grating, that will permit blastant particles to drop through, but makes a suitable flooring surface.

Both the coarse and fine refuse discharge by conduits 202, 234 and 235 can be disposed of in any desired manher as by collecting them in boxes placed underneath the outlets of these conduits and then emptying the boxes. Alternatively, the conduits can be arranged to directly empty their contents in a refuse heap as by means of a conveyor, or can discharge directly into a truck or other vehicle which carts the refuse away. Ladders 240, 242 can be provided to facilitate in maintenance or inspection, and suitable elevated platforms 244, 246 are also desirable for this purpose.

The separation of fines in the second scalping drum assembly is accomplished by the application of suction as by means of manifolds 250, 251 connecting spaced portions of the separators with the source of suction. The same or different source of suction can be connected with blasting room 10 to exhaust any fine particles which are generated during the blasting, to thereby reduce the possibility of their leaking out into the surrounding air to render it unhealthful. A connection box 260 which may contain one or more baffies is conveniently used for connecting the interior of room 10 with a suction tube 262. Tube 262 and manifolds 250, 251 can be joined together to a larger tube used as a principal suction supply conduit.

Room 10 can also be fitted with a separate access door, not shown, as well as with viewing apertures so that the blasting operation can be followed. Such viewing apertures should be in the form of very sturdy transparent panels that will withstand the impact of the blastant particles. Tempered glass makes a very good material for this purpose, and should be used in relatively small thick sizes. A covering shield is highly desirable for use with the transparent panel preferably also with an arrangement to retract the shield when it is desired to make an observation.

Additional applications of suction can be made to the Y 4 desired. The leakage of matter from the second scalping drums assembly is effectively kept down by their suction conduits 250, 251, so that no further precautions need be taken there.

Figs. 3 and 4 show in larger scale a typical first scalping drum assembly in accordance with the present invention. Housing 302 which rests on a framework 304, encloses tubular scalping drum 104. The ends of the drum project from each end of the housing and are rotatably held on pairs of horizontally spaced rollers 306, 308. As shown at 310 and 312, friction rims can be fitted around the drum 104 where it is engaged by the rollers. In order to keep the drum from longitudinally moving with respect to the supporting rollers, 'a series of flanges 314, 316 and 318 can also be fitted around the periphery of the drum 104 to coact with an abutment surface held on the casing 302 and/or framework. The side faces of rollers 306, 308 make suitable abutment surfaces for this purpose, but an additional alignment roller 320 closely fitted between two of the flanges and pivotally held on a frame 322 fixed to the housing 302 provides alignment with less friction.

Drum 104 is shown as rotated by driving the rollers 306, 308 which for this purpose can be mounted on common shafts 324 suitable journalled as by journal blocks 334 carried on the upper portion of the framework. A chain and sprocket connection 326 links the shafts with a rotating device such as electric motor 328. A speed reducer 330 driven by means of belt 332 can be inserted in the motor driving connection to provide the desired drum-rotating speed.

Drum 104 is conveniently assembled from short lengths 105 and 107 bolted together as by means of end flanges provided on the individual lengths. Over at least a portion of its assembled length, the drum 104 is perforated to provide blastant receiving apertures 333. On the inside surface of the drum there is also positioned an advancing mechanism so that the blastant dropped into the rotating drum is caused to move longitudinally through the drum toward the discharge chute 102. In Fig; 3 the blastant advancing is shown as effected by a set of helical vanes 341 secured as by welding against the inner face of the drum. The vanes need not have a height of more than one to three inches, nor need they cover more than half the entire length of the drum.

About the portion of the drum exterior which is perforated there can be secured, as shown in Fig. 4, a set of spreader bars or plates 350. These plates are shown as having ears 352 at each end, the ears being secured in place against the flanges of the individual lengths of which the drum is composed. The bolts that fasten the flanges together can also be used to hold the plates 350 in place.

These plates are shown as assembled in somewhat overlapping relationship with one longitudinal edge 354 directly contacting the outer face of the drum, and the other end 356 held some distance away from this face. Edge 356 overlaps the edge 354 of an adjacent plate, but is spaced therefrom to provide a passageway 358 through which blastant particles will drop.

The drum 104 is arranged to rotate in the direction of arrow 360 so that the blastant particles dropping through the drum perforations at the low end of the drum merely fall on the spreader plate 350 and do not drop 03 the spreader plate until the rotation has carried it far enough to be sufficiently tilted for the particles to slide out.

The blastant discharge hopper 106 is formed from the portion of the housing 302 that is under the section of the drum which carries plates 350. An access opening such as hinged cover 362 can also be provided on the housing. To make the application of suction more effective the housing ends can have walls 364 that provide only a small amount of clearance for the drum to fit through. In fact the walls 364 can overlap with the flanges 316, 318. The housing is split into upper and lower halves to enable assembling the overlapping Walls about the drum.

The second scalping drum assembly 200 is shown in greater detail in Figs S and 6, and is generally similar to the first assembly 100. A housing 402 for this second separator is mounted on elevated framework 404 and encloses a relatively long scalping drum 405. This drum has near one end a friction rim 412 which rests on a pair of rollers 408. At its other end drum 405 carries a stub shaft 407 which is held in place as by a set of spokes (not shown) extending centrally of the drum from its inner face. Shaft 407 can be journalled as by means of the journal block 409 and connected to a rotating mechanism such as electric motor 428 by way of a speed reducer 430.

As in the first scalping drum assembly, drum 405 is shown asa combination of short lengths having end flanges joined together. The drum wall is perforated where it extends through the housing 402, and around this perforated section spreader plates 450 can be simiany positioned, although here the plates do not overlap. Through the entire length of the drum there extends an internaladvancing helix which happens in this case to have three vanes 441, 442, 443. The plates 450 in the construction of Fig. 6 are shown as adjustable with one side edge 454 provided with a gasket 455 that seals this edge against the outer face of the drum. The opposite side edge 456 has an adjustable anchoring device shown as cars 452 that have slots 453 through which the securing bolts 457 are fastened. A separate set of ears 459 can be used for holding edge 454 in fixed but tiltable position.

Below drum 405, housing 402 carries a pair of hoppershaped deflectors 464, 465 that direct the dropping blastant particles downwardly to drop in the form of a thin but wide stream 466 spread out more or less uniformly over the entire length of housing 402. Underneath the deflectors is a divider plate 468 shown as adjustably held on the end of chute 470 so that its free edge projects close to the normal path of the falling stream of blastant particles.

Suction manifold 250 opens into one side of the housing 402 at an aperture 474. This aperture is at the general level of stream 466 and relatively close to it. The opposite wall of housing 402 is cut away to provide an air outlet 476 which can be covered with screening if desired, adjacent the stream 466.

The movement of air through the stream under the influence of suction causes the lighter particles to be blown over and drop onto divider plate 468 so that they fall through chute 470 into the fine refuse duct 234. The heavier blastant particles are not blown over very effectively and by reason of their higher momentum fall through a path that carries them beyond the free edge of divider plate 468. These heavier particles drop into the supply hopper 210.

A feature of the present invention is that very little attendance or maintenance is required with the above type of blastant recirculation. The usual source of trouble in prior art arrangements is that wires, such as core wires, become wedged in place in the perforations of a separator, and then blastant particles pile up around the wedged wires to finally obstruct so much of the separator as to call for cleaning. With the scalping drum of the present invention these types of wires can still become lodged in the perforations of the drum. However they are kept by the spreader plates from falling through and when the drum has rotated through 180, the portion of the drum in which the wire is lodged will be inverted and the wires will automatically drop out.

A single pass through a scalping drum does not provide a sufficiently sharp separation. As a result wires, particularly of smaller sizes, still manage to make their way into the throwing wheel feed. At this portion of the blastant particle cycle, it is carried through the narrowest conduit and small wires will tend to jam. If no jamming occurs then the small wires will make their way to the direction controlling mechanism of the rapidly rotating wheels and'cause some damage: there; somctimeseven breaking offa throwing blade.

The combination of two scalping drum assemblies inseries reduces to the vanishing point any such likelihood.-

The perforations in the scalping drums can be adjusted so that the first will pass particles somewhat coarser thandesired for feeding to the throwingwheels. The'sec'ond: scalping drum will then have smaller perforations to separate out such coarser particles; In this way the first scalping drum will recover most of the reuseable' corewires and the like with very little admixture of coarse refuse. Similarly the coarse materials separated out from the second scalping. drum assembly will be substantially all refuse with very few reuseable wires. This coarsematerial can be discarded without further examination.

A further feature of the present invention is that one of the separator drums can be arranged to distribute the recycling blastant relatively uniformly over a substantialwidth so that the fines separation is very readily accon'h plished with the same structure. Furthermore, this distribution makes it very convenient for a plurality of separate blasting projection units to be supplied With blastant, inasmuch as the units can have their individual supplies connected to receive blastant from different por tions of that width.

The invention does not require" any particular form of blasting apparatus. By' Way of example pneumatic or hydraulic blastant projecting streams can be used instead of the throwing wheels, and still obtain the benefits ofthe invention. Different types of blasting enclosures, and in fact no enclosure at all need be provided. The types of work handling articles such as tumbling conveyors, revolving barrels, rotating tables and the like are also highly suited for the recycling system of the present invention. However, further details of the illustrated blasting apparatus are set forth in the above-mentioned Huyett patent.

The scalping drum assemblies themselves can also be modified in many respects. The drums can have axially disposed shaft connections on both ends, bafiles can be provided at the discharge ends of the drums to reduce the cross sectional areas of the passageway through which air is admitted, for diminishing the load on the suction supply. Such a baflle is shown at 490 in Fig. 5. The helical advancing vanes can be reduced or increased in number and/or extent. The vanes can be partially or entirely eliminated, particularly if other means such as gravity is used to keep the recycling material passing through in the proper direction. By way of example the longitudinal axes of the scalping drums can be tilted downwardly in the blastant travel direction to provide a blastant advancing motion suflicient for all purposes without the use of helical vanes.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope hereof, it is to be understood that the invention is not limited to the specific embodiments hereof except as defined in the appended claims.

What is claimed is:

1. In a work blasting apparatus, a recycling system for collecting particles resulting from a blasting operation, separating re-usuable blastant particles from nonreusable particles, removing the non-reusable particles, and returning the blastant particles to a blasting position where they are again available for use in a blasting operation, said recycling system comprising a hopper positioned to receive the particles resulting from a blasting operation, conveying means to convey said particles to a first separating device, said first separating device comprising a rotatable, perforated, open-ended, hollow drum, an advancing mechanism in said drum for advancing the particles, axially of said drum, from one open end to the second open end thereof, while it rotates, said drum acting to sift particles, of a size determined by the perforations therein, through said perforations While it rotates and, at the same time, actuating said advancing mechanism to convey larger particles axially therethrough, means at; said second'open end to convey said larger particles away from said separating device, transfer means to transfer those particles which are sifted through the perforations of said drum, to a second separating device, fluid-pressure means in said second separating device for separating the particles therein into predetermined size classifications, means to separately collect the particles of each of said size classifications, and means for returning the particles of one of said size classifications, comprising the blastant particles, to said blasting position.

2. The invention of claim 1 wherein said first separating device is positioned in a vertical plane below said blasting position, wherein said second separating device is positioned in a vertical plane above said blasting position, and wherein said transfer means includes an elevator mechanism for elevating the sifted particles from the vertical plane of said first separating device to the vertical plane of said second separating device.

' 3. The invention of claim 1 wherein cover plates are provided on said perforated drum, said plates being arranged to overlie said perforations in such a manner that each plate has one edge overlapping an edge of the plate adjacent thereto around the periphery of the drum, said overlapping edges being spaced from each other in a radial direction relative to said drum.

4. A scalping drum assembly comprising a framework, a hollow drum rotatably mounted in said framework,

8 perforations on the peripheral area of said drum, means to rotate said drum and guide means to guide said drum during its rotation, the means for rotating said'drum comprising a plurality of rollers contacting the outer periphery of said drum, means to drive said rollers in synchronism, and friction rim means on the outer periphery of said drum to frictionally engage with said rollers, said guide means comprising a channel on the outer periphery of said drum and a guide roller pivotally connected to said framework for adjustment into and out of a position within said channel wherein it frictionally engages the side walls defining said channel.

References Cited in the file of this patent UNITED STATES PATENTS 677,691 Packer July 2, 1901 846,140 Rapp Mar. 5, 1907 1,511,025 Christoph Oct. 7, 1924 1,549,102 Arpin Aug. 11, 1925 1,710,168 Hull Apr. 23, 1929 1,994,610 Huyett Mar. 19, 1935 2,093,446 Huyett Sept. 21, 1937 2,247,385 Huyett July 1, 1941 2,696,910 Ljungdell Dec. 14, 1954 FOREIGN PATENTS 58,112 Germany Aug. 7, 1891 65,176 Germany Oct. 28, 1892

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