US3344999A

US3344999A - Double impeller impact breaker

Info

Publication number: US3344999A
Application number: US404755A
Authority: US
Inventors: Norman H Kessler; Floyd A Lillig
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-10-19
Filing date: 1964-10-19
Publication date: 1967-10-03
Anticipated expiration: 1984-10-03

Description

Oct. 3, 1967 N. H. KESSLER ETAL 3,344,999

DOUBLE IMPELLER IMPACT BREAKER Filed Oct. 19, 1964 '2 Sheets-Sheet 1 FIG FIG 2 INVENTORS NORMAN H KESSLER A. LILLIG BY 4 f 7 ATTORNEY Oct. 3, 1967 Filed Oct. 19. 1964 N.H.K ESSL.ER ETAL DOUBLE IMPELLER IMPACT BREAKER 2 SheetsSheet 2 INVENTORS NORMAN H. KESSLER FLOYD LILLIG BY 44% {ii 1N4;

ATTORNEY United States Patent ()fiice 3,344,999 DOUBLE IMPELLER IMPACT BREAKER Norman H. Kessler and Floyd A. Lillig, Cedar Rapids,

Iowa, assignors to Norman H. Kessler, Cedar Rapids,

Iowa, and Harriet F. Derrick, Chula Vista, Calili,

tenants in common Filed Oct. 19, 1964, Ser. No. 404,755 3 Claims. (Cl. 241-154) ABSTRACT OF THE DISCLOSURE A double impeller impact breaker employing, in its preferred form, a pair of impellers having equal hammer circles, both impellers being driven in the same direction and at the same speed, the primary impeller initially receiving the material to be crushed having fewer hammers than the secondary impeller and a speed of rotation effective to permit material to enter its hammer circle and be eflectively crushed, the material thereafter being propelled therefrom toward the secondary impeller at a velocity sufiicient to penetrate the hammer circle of the latter.

Crushing apparatus of the double impeller impact type is well known to those skilled in that art where rocks, ores and similar hard materials are broken into smaller pieces of a desired size for a particular use. These double impeller impact breakers produce what is commonly referred to as dual impact action in which two impellers cooperate with stationary breaker bars to break up the material fed to the machine. The raw material is fed into the rotating impellers which carry a plurality of impeller bars or hammers that break up the rock by impact and also forcibly direct the material against the stationary breaker bars where the impact produces further disintegration of the material.

In some machines of this type, the two impellers rotate in opposite directions so that material fed between them is forcibly ejected upwardly and outwardly against stationary breaker bars located to each side of the impellers. Other machines of this type employ the principle in which both impellers rotate in the same direction, the material being directed into the path of the first impeller which produces initial breakage and directs the material forcibly against a single grate structure located adjacent the second impeller where only the material of finished size is immediately discharged. The remain-ing oversized parti cles are deflected by the grate structure and directed into the path of the second rotating impeller where the material is further broken up.

In this second type of impact breaker, in which the impellers rotate in the same direction, most of the break ing is accomplished by impact with the rotating impellers. However, because of the low feed height which is commonly used on these machines, and because all the material is initially fed to the first or primary impeller, the latter receives considerably more wear than the more remote or secondary impeller. This is because the material does not attain suflicient velocity to penetrate the hammer circle of the primary impeller to any great extent and therefore the material scuffs oflf the ends of the hammers or bars causing excessive wear. This problem can be corrected in part by slowing down the primary impeller thereby producing a greater time interval between the 3,344,999 Patented Oct. 3, 1957 hammers on the primary impeller and thus greater opportunity for penetration of the material into the hammer circle. However, by slowing down the speed of the primary impeller, the peripheral velocity of the hammers is also reduced with a result that the material is not struck with sufficient impact to do an efficient breaking job. The inadequately broken, oversize particles of material are then transferred over to the secondary impeller which must then accomplish most of the work, and as a result its hammers will wear excessively. Slowing down the primary impeller also reduces the elficiency and capacity of the machine.

- Summary of the invention It is therefore the chief object of our invention to provide an improved impact breaking apparatus of the double impeller type in which both impellers rotate in the same direction. According to the principles of our invention, we provide an impact breaking apparatus in which the secondary impeller contains a greater number of hammers than the primary impeller thus providing for a greater time interval between the hammers of the primary impeller even though it may be rotating at substantially the same speed as the secondary impeller. With this ar rangement, the hammers on the primary impeller have the same peripheral velocity and produce an impact equivalent to that of the secondary impeller. A machine constructed according to the principles of our invention, in which, for example, the primary impeller has fewer hammers but is rotated at the same speed as the secondary impeller, thus produces material at substantially the same capacity as prior art machines of this type. However, the work load, as well as the power requirements for each impeller, is more evenly distributed between the two impellers, the increased breakage achieved by the primary impeller augmenting its hammer life.

These and other objects and features of our invention will be more readily apparent from -a consideration of the following detailed description of the preferred form thereof.

Brief description 0] the drawing FIGURE 1 is an elevational side view of a crushing apparatus constructed according to the principles of our invention and shown with the side panel removed to disclose interior details;

FIGURE 2 is a side elevational view of the other side of the crushing apparatus; and

FIGURE 3 is an end elevational view of the crushing apparatus, the view being of the feed end of the machine.

Description of the preferred embodiment Referring now to the drawings, the crushing apparatus comprises a generally rectangular enclosure consisting of a front or feed end wall 10 and a rear end wall 1'2 joined by two

side walls

14 and 16 and a top wall 18. The

crushing unit shown can be adapted for installation in any mon feed ingress or mouth 21 which is covered by a plurality of depending

chains

22 and 24, respectively. Cha

ns

22 and 24 permit the material to be fed into the crushing unit while minimizing the possibility of some of the material being thrown out of the unit through feed ingress 21. The material can be fed into feed ingress 21 in any suitable manner, such as by a feeder of known type (not shown), and the incoming material is guided into the path of the impellers by an adjustable feed plate 26.

Inside the crushing unit are rotatably mounted a primary impeller 28 and a secondary impeller 30. These impellers are mounted for rotation about parallel, horizontally disposed

shafts

32 and 34, respectively, which turn in suitable bearings 33 carried outside

side Walls

14 and 16. The ends of

shafts

32 and 34 are extended a suflicient distance beyond side wall 14 to receive

drive sheaves

36 and 38, respectively, which are driven by belts or other suitable means from a power source (not shown). As shown in FIGURE 1, the primary impeller 28 is located near the feed end of the machine beneath the adjustable feed plate 26, the angle of which can be adjusted so that the incoming rock is guided into the path of the primary impeller 28. The primary impeller 28 carries two diametrically opposed, reversible hammers 40 which are locked in place with wedge blocks 42. The secondary impeller 30 carries three equally spaced hammers 44 also held in place on impeller 30 by suitable wedge blocks 46. The primary impeller 28 and secondary impeller 30 are driven preferably at the same peripheral speed and in the same direction, as indicated by the arrows in FIGURE 1, such as to propel the material toward the rear end wall 12. The hammer circles, of the

impellers

28 and 30, which are the circles described by the outer edges of the hammers on the impellers, are preferably closely adjacent each other.

As the incoming rock is fed into the crushing unit and guided into the path of the primary impeller 28, the material penetrates the hammer circle and is intercepted by the hammers 40, being broken up by the impact and simultaneously projected upward and to the rear of the crushing unit. A series of spaced, horizontally disposed breaker bars 48 are mounted within the enclosure of the crushing unit along the top and upper rear portion thereof ahead of rear wall 12. Most of the material which has been reduced by impact with the primary impeller 28 to a finished size, passes down by impeller 30- and is discharged from the crusher. Particles of material which are oversized are broken up against breaker bars 48 and deflected therefrom back downwardly into the path of the secondary impeller 30 where they are broken by further impact of the hammers 44. Preferably, breaker bars 48 function primarily to further break up oversize material. Alternately, breaker bars 48 may be of a form and arrangement which function primarily to permit only a predetermined maximum size of material to pass therethrough and be discharged from the crusher. In any event, the process is repeated until the material is small enough to pass down by impeller 30 (and/or through breaker bars 48 in the alternate arrangement just referred to). A stripper bar 50, mounted below the lowermost breaker bar 48 adjacent the hammer circle of secondary impeller 30, regulates the maximum size of material permitted to pass down by impeller 30. The mounting 52 for the stripper bar 50 is of any suitable design that permits its proximity to the hammer circle of the secondary impeller 30 to be changed, the use of shims 54 being shown in the drawings for this purpose. Additional details of the construction and functioning of the machine are well known to those skilled in the art, the machine being basically a double impeller impact breaker with the exception of the rotor construction and operation.

Accordingly, in order to balance the wear on the hammers and the amount of work done by each impeller, we have provided a primary impeller which has fewer hammers than the secondary impeller. If, as is preferred,

both impellers have hammer circles of equal diameter and are rotated at the same speed so that the peripheral speed of each is sufiicient for efficient reduction of the material, the intervals between hammers on the primary impeller will be greater than the intervals between the hammers on the secondary impeller. Hence, increased penetration of the rock into the hammer circle of the primary impeller has been provided without decrease of the peripheral velocity of the hammers on the primary impeller below that necessary for efiicient crushing. Thus, our invention, as embodied in the particular application thereof just described, substantially equalizes the wear and work load on each impeller, resulting in more efiicient breakage of the material as well as lengthening the overall life of the hammers.

It will be understood by those skilled in the art that the objects of our invention can be accomplished using various combinations of different numbers of hammers on the primary and secondary impellers as well as different impeller speeds. The important thing is that the primary impeller have fewer hammers than the secondary impeller and a speed of rotation sufficient to efficiently crush the incoming material and project it therefrom at a velocity greater than that with which it entered the hammer circle of the primary impeller. The secondary impeller can carry a larger number of hammers than the primary impeller without impairment of its crushing ability even though rotating at the same speed than the primary impeller because the material enters the hammer circle of the secondary impeller at a higher velocity than it enters the hammer circle of the primary impeller. Furthermore, it is not necessary that both impellers have the same peripheral speed inasmuch as different speeds of each may be accommodated by varying the number of hammers on each. The essential thing is that the combination of the number of hammers on each impeller and their peripheral speeds afford efiicient and substantially equal service by each impeller.

Accordingly, the foregoing preferred form of the invention has been shown for purposes of illustration only and it will be apparent to those skilled in the art that various other revisions and modifications can be made in the specific construction of the illustrated embodiment without departing from the spirit and scope of the invention. Thus it is our intention that any such revisions and modifications be included in the scope of the following claims.

We claim:

1. In an impact breaker of the double impeller type having an enclosure provided with an upper material feed inlet and a lower material discharge outlet, a primary impeller rotatable about a horizontal axis in said enclosure and having a primary hammer circle, said primary impeller being disposed below said feed inlet effective to permit material introduced therethrough to gravitate to said primary hammer circle, a secondary impeller rotable about a horizontal axis in said enclosure and having a secondary hammer circle, the axis of said secondary impeller being laterally spaced from the axis of said primary impeller so that said hammer circles thereof lie closely adjacent each other, stationary breaker means disposed in said enclosure and spaced above said secondary hammer circle and to the side thereof remote from said primary hammer circle, and driving means for rotating each of said impellers at selected speeds, the direction of rotation of each of said impellers being identical and such that material entering said feed inlet is projected by said primary impeller toward said secondary impeller and by both of said impellers toward said breaker means, the improvement comprising: one or more impact hammers mounted on and extending from the periphery of said primary impeller and describing said primary hammer circle, and two or more impact hammers mounted on and extending from the periphery of said secondary impeller and describing said secondary hammer circle,

the number and spacing of said hammers on each of said impellers and the selected speed of rotation thereof in relation to the diameters of their hammer circles all being such relative to each other that material gravitating from said feed inlet may enter the hammer circle of said primary impeller and the material projected from said primary impeller may enter the hammer circle of said secondary impeller and be effectively crushed by the hammers of both of said impellers, the number of hammers on said primary impeller being less than the number of hammers on said secondary impeller.

2. The device of claim 1 wherein the diameters of the hammer circles of said impellers are substantially equal and said impellers are driven at substantially the same speed.

3. The device of claim 2 wherein said primary impeller is provided with two equally spaced impact hammers and said secondary impeller is provided with three equally spaced impact hammers.

References Cited UNITED STATES PATENTS 675,751 6/1901 Moustier 241--154 X 2,618,438 11/1952 Chrystal 241-154 X 2,767,928 10/1956 Hanse et a1. 241154 X 2,862,669 12/1958 Rollins 241154 FOREIGN PATENTS 706,552 5/1941 Germany.

ANDREW R. JUHASZ, Primary Examiner.

Claims

1. IN AN IMPACT BREAKER OF THE DOUBLE IMPELLER TYPE HAVING AN ENCLOSURE PROVIDED WITH AN UPPER MATERIAL FEED INLET AND A LOWER MATERIAL DISCHARGE OUTLET, A PRIMARY IMPELLER ROTATABLE ABOUT A HORIZONTAL AXIS IN SAID ENCLOSURE AND HAVING A PRIMARY HAMMER CIRCLE, SAID PRIMARY IMPELLER BEING DISPOSED BELOW SAID FEED INLET EFFECTIVE TO PERMIT MATERIAL INTRODUCED THERETHROUGH TO GRAVITATE TO SAID PRIMARY HAMMER CIRCLE, A SECONDARY IMPELLER ROTATABLE ABOUT A HORIZONTAL AXIS IN SAID ENCLOSURE AND HAVING A SECONDARY HAMMER CIRCLE, THE AXIS OF SAID SECONDARY IMPELLER BEING LATERALLY SPACED FROM THE AXIS OF SAID PRIMARY IMPELLER SO THAT SAID HAMMER CIRCLES THEREOF LIE CLOSELY ADJACENT EACH OTHER, STATIONARY BREAKER MEANS DISPOSED IN SAID ENCLOSURE AND SPACED ABOVE SAID SECONDARY HAMMER CIRCLE AND TO THE SIDE THEREOF REMOTE FROM SAID PRIMARY HAMMER CIRCLE, AND DRIVING MEANS FOR ROTATING EACH OF SAID IMPELLERS AT SELECTED SPEEDS, THE DIRECTION OF ROTATION OF EACH OF SAID IMPELLERS BEING IDENTICAL AND SUCH THAT MATERIAL ENTERING SAID FEED INLET IS PROJECTED BY SAID PRIMARY IMPELLERS TOWARD SAID SECONDARY IMPELLER AND BY BOTH OF SAID IMPELLERS TOWARD SAID BREAKER MEANS, THE IMPROVEMENT COMPRISING: ONE OR MORE IMPACT HAMMERS MOUNTED ON AND EXTENDING FROM THE PERIPHERY OF SAID PRIMARY IMPELLER AND DESCRIBING SAID PRIMARY HAMMER CIRCLE, AND TWO OR MORE IMPACT HAMMERS MOUNTED ON AND EXTENDING FROM THE PERIPHERY OF SAID SECONDARY IMPELLER AND DESCRIBING SAID SECONDARY HAMMER CIRCLE, THE NUMBER AND SPACING OF SAID HAMMERS ON EACH OF SAID IMPELLERS AND THE SELECTED SPEED OF ROTATION THEREOF IN RELATION TO THE DIAMETERS OF THEIR HAMMER CIRCLES ALL BEING SUCH RELATIVE TO EACH OTHER THAT MATERIAL GRAVITATING FROM SAID FEED INLET MAY ENTER THE HAMMER CIRCLE OF SAID PRIMARY IMPELLER AND THE MATERIAL PROJECTED FROM SAID PRIMARY IMPELLER MAY ENTER THE HAMMER CIRCLE OF SAID SECONDARY IMPELLER AND BE EFFECTIVELY CRUSHED BY THE HAMMERS OF BOTH OF SAID IMPELLERS, THE NUMBER OF HAMMERS ON SAID PRIMARY IMPELLER BEING LESS THAN THE NUMBER OF HAMMERS ON SAID SECONDARY IMPELLER.