US2490564A - Vegetable pulp shredder screen having cutter blades - Google Patents

Description

Dec. 6, 1949 D. B. VINCENT 2,490,564

VEGETABLE PULP SHREDDER SCREEN HAVING CUTTER BLADES Filed Aug. 10, 1945 2-Sheets--Sheet 1 Dec. 6, 1949 D. B. VINCENT 2,490,564

VEGETABLE PULP SHREDDER SCREEN HAVING CUTTER BLADES Filed Aug. 10, 1945 2 Sheets-Sheet 2.

awe/whom Rik/i!) Z. Vahce/rf May/Z26 Patented Dec. 6, 1 949 OFFICE VEGETABLE PULP SHREDDER SCREEN HAVING CUTTER BLADES Daniel B. Vincent, Tampa, Fla.

Application August 10, 1945, Serial No. 609,961

6 Claims.

The present invention relates to vegetable pulp shredding machines of the type used for shredding or comminuting citrus waste and the like for the manufacture of stock feeds and the like, and more particularly to an improved screen for such machines, and aims generally to improve existing devices of that type.

Citrus waste material is the peel, rag and seed or a mixture thereof of citrus fruits and is so called because it is the waste from citrus canning and processing plants. Much of this citrus waste material is processed by shredding, chemical treatment and drying to produce a highly desirable stock and cattle feed. A typical process for the processing of citrus waste into such a stock feed is disclosed in my prior patent No. 2,215,944, granted September 12, 1940.

Heretofore, the citrus waste material, comprising the half or quarter sections of grapefruit, oranges and the like, have generally been shredded in a hammer mill, generally consisting of a rotor having swinging or fixed blades of from to inch in thickness, adapted to force the material through an apertured metal plate or screen, the round apertures of which may vary from to 1 inch or more in diameter, depending upon the desires of the user. These mills required a relatively great amount of power for operation as the material must be churned in the mill until it finds an opening for discharge. Furthermore, the citrus waste material heretofore shredded by conventional hammer mills has been very non-uniform in particle size, resulting in a feed containing a substantial amount of fine dust and more or less large particles.

Such a non-uniform particle size material is very difiicult to dry. Citrus waste material contains approximately 80 to 85 percent moisture and is conventionally dried in a heated oven or dryer to a condition Where it contains 10 percent or less moisture. If the drying operation is maintained sufiiciently long to dry the large particles, the smaller particles are burned. Hence, producers commonly adjust the drying to an intermediate particle size, and then screen off the fine, overdried particles, and the larger under-dried particles. The over-cooked fines may be sold at a lower price or burned in the dryer furnace and the large under-dried particles are reground and again dried.

One of the primary objects of the present 111-. vention is the provision of an improved citrus waste shredder and screen therefor that will produce a highly desirable shredded product under substantially less power requirement than heretofore required.

A further object of the invention is the provision of an improved shredder and screen therefor that will efiectively comminute citrus waste ma.- terial into particles of substantially uniform cross-sectional area, that may be more completely and uniformly dried in the initial drying operation, and thus dispose of the necessity for screening and re-shredding and drying of a portion of the product.

A further object of the invention is the provision of an improved shredder and screen therefor for citrus waste material that will produce a highly desirable shredded product of elongated particles of substantially uniform cross-sectional area and substantially free from dust. Such elongated particles tend to curl or crinkle during drying and offer a relatively large surface to absorb water quickly when the material is used as a feed.

A still further aim and object of the invention is the provision of a shredder suitable for citrus waste material that will be simple in construction, efficient in operation and easily maintained in operative condition and repair.

Other aims and objects of the invention will be apparent to persons skilled in the art to which the invention pertains from a consideration of the accompanying drawings and annexed specification, illustrating and describing certain preferred embodiments thereof.

In the drawings Fig. 1 is a rear elevation of a shredding machine embodying the invention, a portion of the outer casing being broken away to show part of the mechanism in the interior thereof;

Fig. 2 is a side elevation of the machine shown in Fig. 1;

Fig. 3 is a transverse vertical sectional view of the machine as taken on the line 3-3 of Fig. 1;

Fig. 4 is an end elevation of one form of screen embodying the invention;

Fig. 5 is an enlarged top plan view thereof;

Fig. 6 is an enlarged detail sectional view 50 thereof as taken on the line 66 of Fig. 5.

Fig. 7 is an end elevation of a modified form of screen;

Fig. 8 is a side elevation of a fragmentary portion of one of the screen knives used in the screen of the type shown in Fig. 'I.

Fig. 9 is an enlarged detail sectional view taken on the line 9-9 of Fig. 7;

Fig. 10 is a transverse sectional view of a further modified form of screen.

Referring more particularly to the drawings, the mill comprises a housing l preferably in the form of a receptacle II and a removable cover or top |2 which may be hingedly connected as at I3 to the receptacle so as to permit the cover to be swung upwardly to open position, as shown in full lines Fig. 2, when access to the interior of the housing is required. The cover may be provided with a material inlet l4 preferably above the receding side of a rotor, and the bottom of the receptacle l0 may, if desired, be provided with an outlet l5 for the continuous discharge of shredded material. The inlet l4 has a retaining wall |4 adjacent the path of the rotor and preferably terminates in the plane of the rotor axis.

The receptacle [0 may be provided with spaced bearings |8 for a rotor shaft l9 having a pulley or other suitable means for applying rotation to the shaft I9. Preferably, the rotor shaft is mounted wholly in the receptacle part II of the housing In, so that the cover |2 thereof may be moved free from the shaft l9 and parts of the rotor mounted thereon.

The rotor comprises a series of blades disposed radially of the shaft and removably and reversibly connected thereto, and are preferably disposed in planes normal to the axis of the shaft. These blades may either be cutting blades adapted to comminute the material fed to the rotor from the inlet l4, or they may be beater blades adapted to feed the material under pressure to a cutting screen, depending upon the desired size of comminuted material.

According to an illustrated embodiment of the invention, the rotor may comprise a plurality of supports 2|, herein shown in the form of circular discs, suitably secured to the shaft |9, as by a key 22, in spaced relation longitudinally of the shaft IS. The supports 2| provide mountings for blade carriers 23 which are preferably spaced radially from the shaft and disposed in parallel spaced relation therewith. The blade carriers are conveniently in the form of rods or bars extended through aligned openings 23 in the supports near the outer ends or peripheral edges thereof, and may be releasably secured to the end supports 2| by a suitable removable fastening, such as for example a cotter pin or the like. The blade carriers 23 may also include bushings or washers 26 surrounding the carrier and disposed between adjacent supports 2| for properly positioning the blades 21 on the carriers 23. The blades 21 may be formed of elongated metal strips either of thin metal with longitudinal cutting edges 28 or of thicker metal with relatively blunt longitudinal feeding edges. The blades 21 are preferably formed with a central aperture 30 to receive the blade carrier 23, and the opposite ends of the blades are notched as at 3| to receive a locking rod 32 extended through aligned openings 33 in the supports 2|. Preferably the notches 3| are of larger radius or size than the central opening 30 so that they may fit over bushings 34 on the locking rod 32.

The above described construction of rotor, blade carrier and lock provides a suitable means for mounting the blades in the rotor for ready replacement while the blade construction provides a means for readily reversing the position of the blades and rendering available for use both longitudinal edges thereof.

It will be noted in Fig. 3 that the blades of the rotor,moving in the direction of the arrow, will engage the material in the inlet i4 and move it toward the rear wall of the inlet, the bottom edge of which preferably is substantially in the plane of the shaft l9 or axis of the rotor. Below the horizontal axis of the rotor is a screen 38, preferably semi-circular in transverse section, one upper edge of which is in substantial continuation of the rear wall of the inlet, the said screen presenting a series of closely spaced substantially semi-circular knives slightly spaced from the paths of the rotor blades and extending throughout a substantial portion of the rotation thereof, for example throughout approximately 180 degrees of the movement of the rotor blades.

The screen may embody one of several different constructions shown in the drawings, and preferably includes a frame replaceably mounted in the housing container H and including semicircular end members and side rails between which are mounted a longitudinal series of closely spaced substantially semi-circular knives having cutting edges closely adjacent to and following the path of the blades throughout a substantial arc of the travel thereof.

Referring more particularly to Figs. 4 to 6 inclusive, the screen comprises substantially semicircular end sections 39 and longitudinal side rails 40 secured together in any suitable manner. The end sections 39 are provided with a plurality of transverse apertures 4| and outer countersunk or recessed nut-receiving sockets 42 for housing the nuts 43 of tie rods 44 extended through the aligned apertures 4| of the end sections, thus permittin the end sections of the frame to snugly fit the side walls of the housing receptacle.

According to this form of the invention, the cutting knives are in the form of thin, relatively wide semi-circular knives 45 having apertures 45 therein adapted to align with the apertures 4| of the end sections, and thin relatively narrow semicircular cutting knives 41 having notches 48 to align with the apertures 4| and 4'5. The cutting knives 45 and 41 conveniently are formed of stainless steel of 6 inch thickness or thinner, the knives 45 conveniently being about to 1 inch wide (radial width) and the knives 41 about to inch wide. The knives 45 and 41 are assembled between the end frames 39 in alternating relation and are tied together by the tie rods 44 passed through aligning apertures 4|, 46 and notches 48. The knives 45 and 41 are maintained in proper spaced relation on the tie rods in spaced notches formed by suitable spacing means 49, for example bushings or washers.

The provision of a screen having alternately arranged narrow and wider semi-circular knives combines the advantages of a light weight construction, adequate rigidity and strength, while maintaining a self-clearing screen.

A slightly modified form of screen is shown in Figs. '7, 8 and 9 wherein the semi-circular end sections 50 may be of flanged construction, for example angles in cross-section, providing a flange 5| and web 52, the end sections 50 being tied together by side rails 40. The webs 52 of the end sections 50 are formed with a series of non-circular openings 53 to receive correspondingly shaped reduced ends 54 of spacer bars 55, the shoulders 56 of the bars at the reduced ends 54 serving to maintain the end frames in proper spaced relation. The spacer bar 55 may be maintained in assembled relation with the end section 50 by means of a pin 55 passed through aperture 51 in the reduced end 54 of the bar.

The spacer bars 55 are provided with a series of notches 58 throughout their length, which are of a width to receive the semi-circular knives 59 which are notched as at 60, providing a mortised joint between the spacer bars and cutting knives. The ends of the semi-circular cutting knives may be securely held in the frame by a rod 6| passed through openings 62 in the knives at the end frames.

The spacer bars 55 advantageously may be in the form of cutting bars, being provided with knife-edged sections 55 interposed between the semi-circular knives 59. Preferably the cutting edges of the knife edge sections 55 extend slightly above the upper edges of the knives 59 as shown in Fig. 9, and the knives may be inclined forwardly from a radial position toward the advancing rotor blades to aid in effectively shredding the material.

A further modified form of screen is shown in Fig. 10. According to this modification of the invention the transverse semi-circular knives may be composed of a plurality of straight bars 59 connected between circumferentially spaced tie rods 44 between the end frames 50 and providing segmentally arranged cutters. If desired, other cutters 63 of wire may be interposed between the adjacent cutters 59 where extreme fineness of the shredded material is desired.

In operating the machine, the rotor is set in motion at a desirable speed, for -example 1800 R. P. M. The material to be shredded, i. e. the citrus cannery waste comprising the whole culls, the half or quarter sections of peel with the rag or seed is fed to the machine through the inlet 14 above the receding side of the rotor which is rotating in the direction of the arrow, Fig. 3. The waste is immediately engaged by the rotor blades and is cut into narrow threads, particularly when relatively thin blades are used. In any event the material is carried by the blades 21, particularly the outer notched ends thereof, and is carried down over the spaced semi-circular cutting blades of the screen through which the material is forced by the centrifugal force of the rotating rotor.

Some of the material may not be forced through the screen but will be carried around past the screen by the blades 21. This material is thus engaged by an arcuate plate section 10 one end of which is hinged as at H to the top [2, and the other end being free to move by gravity toward the rotor blades. The movement of the free end of the plate section 10 inwardly toward the rotor blades 21 is preferably limited by suitable means such as a pin 13 on the plate sliding in a slot 14 in the cover l2. The plate thus presses the material carried past the cutting screen inwardly toward the axis of the rotor insuring that it will be carried around to the inlet throat l4 so that it may again be subjected to the cutting screen under the centrifugal force of the rotor.

The size of the pieces of shredded waste may be varied considerably by the selection of the type of rotor blade used. When thin blades formed with sharpened cutting edges are used, the citrus waste material is initially cut by the rotor blades principally to force the material through the cutting screen.

From the above it will be seen that I have provided a machine that cuts the citrus waste pulp into shreds instead of beating it into particles as in the case of hammer mills heretofore use. As a result, I am able to shred citrus pulp at about one-sixth the power required for conventional hammer mills operating at the same tonnage rate. The more uniform size of the shreds makes possible a more uniform and easier drying of the shredded waste.

My invention is not to be restricted to the particular details shown and described, which are intended merely as illustrations of the invention, and the scope of the invention is best defined in the appended claims.

1. A screen for a vegetable pulp shredder comprising a substantially rectangular frame having longitudinal side rails and substantially semicircular end rails connected thereto, a plurality of spaced tie rods bridging the space between said end rails and including a side tie rod located closely adjacent each side rail, some of said tie rods having a plurality of spaced notches, a plurality of thin, relatively wide smooth-edged cutter blades of a thickness not exceeding approximately inch supported by said tie rods between said semi-circular end rails and having portions thereof positioned in said notches, said cutter blades being spaced apart longitudinally to provide narrow elongated openings therebetween disposed circumferentially to the line of feed to said screen.

2. A screen as defined in claim 1 further characterized in that each of the cutter blades is provided with an aperture adjacent one end thereof and a tie rod is extended through said aperture and said end rails to removably mount said cutter blades on said frame.

3. A unitary screen assembly for a vegetable pulp shredder comprising a substantially rectangular frame having longitudinal side rails and substantially semicircular end rails connected thereto, a plurality of spaced tie rods bridging the space between said end rails and including a side tie rod located closely adjacent a side rail, a plurality of relatively wide cutter blades supported edgewise between said semi-circular end rails and being secured at one end to said side tie rod and having interlocking engagement with at least one of said other tie rods, said cutter blades being spaced apart longitudinally to provide narrow elongated openings therebetween disposed circumferentially to the line of feed to said screen, said cutter blades further being of relatively thin material of approximately inch or less in thickness and having substantially smooth upper cutting edges whereby material fed to said screen is uniformly cut into elongated strips.

4. A screen as defined in claim 3 further characterized in that the cutter blades are of different radial widths to prevent clogging of the screen.

5. A screen as defined in claim 3 further characterized in that alternate cutter blades are of differentwidths to prevent clogging of the screen.

6. A screen as defined in claim 3 further charecterized in that the cutter blades are straight sections supported at their ends by tie rods.

DANIEL B. VINCENT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Emmott et a1 Jan. 31. 1911 15 Number Number Name Date Boero Mar. 2, 1915 Armstrong Feb. 1, 1916 Stoner July 1. 1930 Levin Jan. 6, 1931 Bare] Oct. 10, 1933 Ossing et al Dec. 27. 1938 Dim Oct. 1, 1940 Thomas Mar. 30, 1943 FOREIGN PATENTS Country Date, Great Britain Jan. 31. 1911 Germany Sept. 14, 1932

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