US3622088A - Apparatus for depithing fibrous vegetable materials - Google Patents

Abstract

The disclosed depithing apparatus separates fibrous vegetable materials into useful fiber and discardable pith portions for papermaking or the like. The apparatus is vertically constructed to provide gravity feed therethrough for the vegetable materials. Rotating hammers projecting from a rotor break up the materials and centrifugally force the pith through a surrounding screening member. Separate vertically oriented discharge chutes below the rotor convey the separated fiber and pith out of the apparatus, and a baffle is provided to direct the pith into its respective discharge chutes to prevent clogging. Separate embodiments of the apparatus are shown for use in existing sites having limited headroom or insufficient room for full length discharge chutes.

Description

: tent Kenneth M. Gunkel Pan American Industrial Consultants, 322 Main St., Stamliord, Conn. 06%] 834,957

June 20, 1969 Nov. 23, 1971 lnventor Appl. No. Filed Patented APPARATUS FOR DEPITHING FIBROUS VEGETABLE MATERIALS 9 Claims, 6 Drawing Figs.

[1.8. CI 241/74, 146/76 A, 241/186, 241/285 Int. Cl 1302c 13/18, B02c 13/286, 1302c 13/284 Field 01 Search 241/49, 74, 285; 146/76 A, 192

2,656,988 10/1953 Smith 241/74 X 2,785,719 3/1957 Dufault 146/76 X Primary Examiner-Robert C. Riordon Assistant Examiner-Gary L. Smith Attorney-Blair, Cesari and St. Onge ABSTRACT: The disclosed depithing apparatus separates fibrous vegetable materials into useful fiber and discardable pith portions for papermaking or the like. The apparatus is vertically constructed to provide gravity feed therethrough for the vegetable materials. Rotating hammers projecting from a rotor break up the materials and centrifugally force the pith through a surrounding screening member. Separate vertically oriented discharge chutes below the rotor convey the separated fiber and pith out of the apparatus, and a bafile is provided to direct the pith into its respective discharge chutes to prevent clogging. Separate embodiments of the apparatus are shown for use in existing sites having limited headroom or insufficient room for full length discharge chutes.

PATENTEDunv 23 I97! 3,622,088

SHEET 1 0F 5 IN Vlz'N'l'OR.

KENNETH M. GUN/(EL BY BLAIR CESAR/ AND 57'. ONGE A TTORNEYS PATENTEDunv 23 l97l 3,622,088

' SHEETEUFS KENNETH M. GUN/(EL BLAIR CESAR/ AND SIONGE A TTORNEYS IN VIL'N'I'OR.

PATENTEDNUV 23 ml 3.622.088

SHEET 3 1F 5 INVIz'N'l'OR. KENNETH M. GUN/(EL BY BLAIR CESAR/ AND SIG/V65 A TTORNEYS PATENTEDunv 23 |97l SHEET 4 [1F 5 INVIz'N'I'OR. KENNETH M. GUN/(EL BY BLAIR CESAR/ AND ST ONGE ATTORNEYS PATENTEUuuv 23 I9?! 3,622,088

SHEET 5 or 5 INVEN'I'OR. KENNETH M. GUN/(EL BY BLAIR CESAR! AND 57: ONGE ATTORNEY APPARATUS FOR DEPITI'IING FIBROUS VEGETABLE MATERIALS BACKGROUND OF THE INVENTION Vegetable wastes such as bagasse, megasse, straw, rice hulls and the like are often used in the manufacture of paper from pulp, and in the production of similar products such as resinresin-impregnated board. The portions of the vegetable materials used for this purpose are the fibers which accordingly must be separated from such unusable portions as the pith which may also contain contaminants such as sand, dirt and other fine materials. For large scale commercial operations this separation must be done mechanically by an apparatus capable of expeditiously and efficiently handling large quantities of vegetable matter material. A number of machines have been devised and used for this purpose but there have been serious disadvantages due to various constructional features.

In many prior art machines the vegetable matter has been fed through in a horizontal direction. This has been accomplished in some instances by the use of specially shaped rotating members called hammers which both beat the material to separate fiber from pith, and which then project the materials horizontally in a predetermined direction until they reach respective discharge chutes. Such specially shaped hammers are costly and difficult to replace, and they are normally operable in only a single direction so that the apparatus cannot be reversed to distribute hammer wear.

Additionally, horizontal machines have tended to develop dead spots," that is areas where material flow is obstructed. A further disadvantage to such machines has been their large size which has also made it difficult to properly encase the rotating members for the safety of the operators. In addition, the horizontal arrangement of the shaft to which the rotating hammers are mounted has made its removal for maintenance difficult and expensive.

In other prior art machines the separated portions of vegetable matter have had to be withdrawn by means of an exhaust fan or similar device. This extra machinery adds appreciably to original cost and maintenance, and also adds to the possibility of a breakdown. Machines of this type may therefore be out of service frequently, and this has the effect of lowering production and raising cost.

Accordingly, representative objects of the present invention are .to provide an apparatus for the depithing of fibrous vegetable materials which is gravity fed and requires no external apparatus for the removal of fiber or pith from the machine interior, and to provide such an apparatus which is simple in design, safe, compact, readily serviceable and efficient and economical in operation.

Other objects of the invention will in part be obvious an will in part appear hereinafter.

SUMMARY OF THE INVENTION The present invention relates to an apparatus for processing fibrous vegetable materials containing pith to separate the fibers from the pith and other contaminants.

The apparatus comprises a generally tubular, vertical housing which is preferably built into a building enclosure but which may also be free standing. A rotor, driven by a suitable motor is suspended within the housing and mounted for rotation about a vertical axis. The rotor carries a plurality of bars or hammers projecting out from the rotor surface and nonnal to the axis of rotor rotation. The rotor and the projecting hammers are surrounded by a screening member containing openings of a size which permit passage therethrough of pith or other contaminants in the vegetable material but which substantially block the passage of fibers.

Thus, vegetable matter fed into the top of the housing falls vertically under the influence of gravity through the whirling hammers. The hammers break up this material separating the pith and any other contaminants such as sand or dirt from the fibers, and act to drive the pith and contaminants through the screening member by centrifugal force. The larger fibers, however, being blocked by the screening member, fall through the rotor area.

The housing below the rotor is divided into several separate discharge chutes. A fiber discharge chute is provided with an entrance preferably centrally disposed at the interior of the housing directly below the rotor so that the separated fibers, still under the influence of gravity, fall through the chute where they may be collected for subsequent processing.

The pith discharge preferably comprises two chutes disposed on either side of the housing and opening into a chamber adjacent the outer surface of the screening member. Accordingly, the pith and contaminants, once having penetrated the screening member, fall under gravitational influence into the discharge chutes provided therefor. A tentshaped baffle is also provided between the interior fiber discharge chute and the pith discharge chutes, and in line with the falling pith. The sloping sides of the baffle slope toward the pith discharge chute openings to facilitate pith removal, with no dead spots which could cause clogging or blockage thereof.

The apparatus is thus completely gravity fed as a result of vertical assembly, and requires no external machinery for removing fiber or pith material from the interior. Further, since the apparatus relies on gravity instead of the rotor shape to move material therethrough, the rotor hammers may be reversed to equalize wear. The vertical assembly also simplifies construction and maintenance, and results in a symmetrical design which allows for a great deal of flexibility in the location of the discharge and feed chutes to suit existing installation sites.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. I is a front elevation view in section of the depithing apparatus of the invention.

FIG. 2 is a side elevation view in section of the apparatus of FIG. 1.

FIG. 3 is a partial side elevation view in section of an alternate motor drive arrangement for the depithing apparatus.

FIG. 4. is an enlarged partial isometric view shown partly in section illustrating the preferred discharge chute arrangement for the depithing apparatus.

FIG. 5 is a partial front elevation view in section of another embodiment of the depithing apparatus.

FIG. 6 is a side elevation view in section of the apparatus shown in FIG. 5.

Similar reference characters refer to similar throughout the several views of the drawings.

parts DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. I the apparatus of the invention is encased in a vertically disposed generally tubular housing It). Housing 10 comprises a main support cylinder 12 (FIG. 2) having bottom flanges 14 which are bolted or otherwise secured to a base support ring I6. As shown base support ring 16 may be built directly into a building structure as part of a cast concrete floor 18. In such an installation, the floor acts as a means for shielding operators against objects accidentally ejected from the apparatus. Alternatively, the entire apparatus may be mounted on structural steel supports in which case supporting feet may be welded to the outside of support ring 16 and bolted or otherwise secured to the beams. The apparatus may also be provided as a free-standing structure in which case base support ring 16 will be well above floor level. In such a case, support ring 16 will preferably be encased in shielding material such as heavy plate.

Still referring to FIGS. 1 and 2, a mounting plate 20 is secured to flanges 21 at the upper end of support cylinder 12. Plate 20 serves as a means for suspending the apparatus rotor 22 within housing 10. Rotor 22 is suspended within the area surrounded by support ring 16 by means of a rotating drive shaft 24. Shaft 24 extends up through plate where it may be directly connected to a drive motor 26, preferably through a flexible coupling 28. It is preferred that drive motor 26 be mounted directly in line with shaft 24, as for example on a motor support ring 30 secured to the top of plate 20. In this way the apparatus may be driven directly without need for any additional mechanism such as drive belts, chains, gear trains or the like.

However, at installation sites where there is limited headroom, or where it is desirable to provide an apparatus operating at other than motor speeds, drive motor 26 may be mounted as shown in FIG. 3. In this embodiment, motor 26 is mounted laterally at about the level of support cylinder 22 on a support arm 32. Driving is accomplished through a plurality of V-belts or a chain drive interconnecting a pair of drive pulleys 36 and 38 respectively connected to motor 26 and rotor shaft 24.

It is important that rotor 22 be maintained centrally positioned within housing 10 to prevent accidental contact between any of the rotor parts and the housing during operation of the apparatus. For this purpose, rotor shaft 24 is enclosed within a shaft barrel 40 as shown in FIGS. 1 and 2. Shaft barrel 40 contains suitable bearing means to withstand the radial and thrust forces exerted by shaft 24 in operation. Barrel 40 is securely fixed at its upper end 400 in support plate 20. To further insure a rigid support for rotor 22, a plurality of stiffening ribs 42 are welded to the outer periphery of barrel 40. Stiffening ribs 42 are essentially triangular in shape and flare outwardly from the rotor end of barrel 40 to a connecting flange 420 which is welded or otherwise rigidly secured to support plate 20. The use of stiffening ribs 42 is advantageous in that the ribs present no obstruction to the free fall of material through support cylinder 22, thus minimizing the chances of clogging or otherwise obstructing the feed of material through the apparatus.

Vegetable materials are preferably fed into the apparatus through support cylinder 12 by means of a gravity feed chute 44 which penetrates through the support cylinder wall at one side thereof as shown in FIG. I. A door 46 may also be provided at the other side of support cylinder 12 to permit access to the interior thereof for maintenance.

The actual separation of fiber from pith and any other contaminants is accomplished by rotor 22. Rotor 22 carries a plurality of bars called hammers 48 (FIGS. 1 and 2) projecting perpendicularly from the surface thereof. Hammers 48 may be either rigidly secured to rotor 22 or may be pivotally mounted on rods or bolts passed through rotor 22. The preferred method of mounting rotor 22 and hammers 48 is disclosed in my U.S. Pat. No. 3,299,477 issued Jan. 24, 1967.

Rotor 22 and projecting hammers 48 are surrounded by a screening member 50 which is preferably in the shape of a one-piece cylindrical ring mounted by flanges 50a to the underside of support cylinder flanges 14. Screening member 50 may be made from solid plate which has been perforated, the important consideration being that the openings through screening member 50 be of a size which will permit the passage therethrough of pith while essentially blocking passage to the fibers. Screening member 50 is mounted concentrically within support ring 16, but has a smaller diameter; it therefore forms with support ring 16 an annular pith chamber 52 surrounding rotor 22.

Thus. when vegetable materials are fed into the depithing apparatus through chute 44, they fall under the influence of gravity into the whirling hammers 48 carried by rotor 22. The action of rotor 22 and hammers 48 breaks up the vegetable material into relatively small pith fragments and larger fiber fragments. The pith, being of small size is then forced through the holes in screening member 50 by centrifugal force imparted by the rotor, and enters pith chamber 52 where it is stopped by impingement against support ring 16. The pith then falls from chamber 52 under gravitational force. The

fiber material, however, being blocked by screening member 50 falls under the influence of gravity directly through the rotor area. Therefore, the vegetable material after having passed through the rotor area is separated and segregated into fiber and pith portions which can then be collected for further processing or disposal as the case may be. The means for discharging the segregated fiber and pith from the apparatus are shown in FIGS. 1 and 2. These means comprise a centrally disposed fiber discharge chute 54 and preferably two laterally disposed pith discharge chutes 56 and 58. As shown in FIG. 4, the pith and fiber discharge chutes are preferably made part of a unitary and boxlike discharge structure 57 which can be conveniently constructed from sheet metal. Discharge structure 57 is preferably provided with an upper flanged periphery 59 in which each side thereof corresponds approximately to the diameter of support ring 16. Support ring 16 is also provided with a lower flange plate 61 preferably made from a square piece of plate corresponding in size to flange periphery 59 and having a central opening corresponding to the outside diameter of support ring 16. Thus, discharge structure 57 may be suspended below rotor 22 by bolting or otherwise securing flanged periphery 59 to flange plate 61, and this may be conveniently done without transition ductwork.

When the depithing apparatus is to be provided as a freestanding device, discharge structure 57 may be fonned of heavier metal plate and reinforced to act as a base support.

Fiber discharge chute 54 comprises a cylindrical ring 60 (FIG. 4) defining the entrance thereto. Ring 60 is telescopically fitted over the bottom end of screening member 50 as shown in FIGS. 1 and 2, and preferably a plastic sealant is used to seal the joint 62 formed thereby. As shown in FIGS. 2 and 4, a forwardly sloping plate 64 projects downward from the bottom of ring 60 to form the rear wall of fiber discharge chute 54. Fiber discharge chute 54 is further defined and enclosed by a pair of sidewalls 66 and 68 and a front wall 70. The forward sloping rear wall permits fiber chute 54 to extend to the front of the depithing apparatus. In this way a separate conveyor 72 (FIG. 2) may be provided under the open exit end 73 thereof to continuously carry away fiber material for further processing.

Preferably, an access door 74 is provided in front wall 70 of fiber chute 54 (FIG. 4) and is pivotally connected along its bottom edge 66 so that it may be pivoted inwardly as shown in FIG. 2. Preferably the height of access door 74 is chosen so that it will come to rest in a horizontal plane against the sloping rear wall 64 of chute 54 when it is opened (FIG. 2). In this way, door 74 acts as a platform from which an operator may inspect or repair the interior of the depithing apparatus. Access door 74 performs a further function in that it completely closes ofi' fiber discharge chute 54 during inspection or repair; it thus prevents any apparatus parts, tools or other contaminating materials from mixing with the fiber and possibly damaging subsequent processing apparatus.

Referring back to FIG. 4, pith discharge chutes 56 and 58 are located at either side of the apparatus adjacent the centrally located fiber discharge chute 54. As shown in FIGS. I and 2, the upper end of each pith discharge chute communicates directly with annular pith chamber 52. Thus, pith material falling under the influence of gravity from within pith chamber 52 enters directly into the pith discharge chutes. The front walls 56a and 58a of the pith discharge chutes preferably slope toward the rear of the apparatus as shown in FIG. 4. In this way the pith discharge chutes may be displaced behind fiber discharge chute 54 so that a separate conveyor 77 (FIG. 2) may be provided below the open exit ends 78 and 79 thereof for transporting the pith to a disposal area.

It is important for all the pith falling from chamber 52 to enter discharge chutes 56 and 58 so that there is no buildup of pith within the apparatus to cause clogging or blockage. To eliminate any dead spots" which might cause such blockage, a baffle 80 (FIG. 4) is disposed within the apparatus adjacent the entrances into the pith discharge chutes. Specifically, baffle 80 comprises a tentlike structure disposed about fiber discharge chute ring 60 with the sloping sides 80a and 80b thereof directed downwardly into chutes 56 and 58. It can thus be seen from FIGS. 1 and 4 that any pith material falling from annular chamber 52 which does not fall directly into the pith discharge chutes will land on baffle sides at): and 80b, and from there be directed into the proper discharge chute.

Referring now to FIGS. and 6, an embodiment of the depithing apparatus is shown which is particularly suited for use in existing installation sites where there is insufficient room for properly inclined discharge chutes. The upper end of this embodiment may be identical to the previously discussed embodiment.

In this embodiment, however, the length of ring 60 of fiber discharge chute 54 is somewhat extended directly below the rotor, and terminated in a funnellike structure 82. Structure 82 forms a discharge chute exit which opens directly over conveyor 72 (FIG. 6). For convenience, the fiber discharge chute may be provided with a slide gate 84 which slides into or out of frame 86 surrounding the exit to respectively close and open said chute. When closed during repair of the apparatus, gate 84 serves to block the mixing of apparatus parts, tools or other contaminants with the fibers, in much the same manner as the previously discussed access door 74.

In order to provide the desired spacing between the fiber and pith discharge chute exits in this embodiment so that separate fiber and pith conveyors 72 and 77 (FIG. 6) can be used, additional pith conveyor means are provided to carry pith from the bottom of discharge chutes 56 and 58 to a laterally displaced exit opening. As shown, these conveyor means preferably comprise a pair of screw conveyors 88 and 90 each journaled at one end 88a and 900 at the bottom of its respective pith discharge chute 56 or 58, below baffle 80. It will be understood, however, that the function of screw conveyors 88 and 90 may also be performed by other types of horizontal conveyors such as belts, air slides or vibratory types. Screw conveyors 88 and 90 each extend laterally from the apparatus through a pith discharge chute extension 92 and are journaled in the far end 941 of extension 92 adjacent the extension exit opening 96. Opening 96 is positioned directly over pith conveyor 77. Conveyors 88 and 90 may be driven by a separate motor 98 through a chain and sprocket drive 100 or the like.

It can thus be seen that in the embodiment of FIGS. 5 and 6, as with the previously discussed embodiment, the feed of fiber and pith materials through the apparatus is accomplished solely under the influence of gravity. The principal difference is that in the embodiment of FIGS. 5 and 6, pith material reaching the bottom of the pith discharge chute is then carried laterally out of the machine by means of a screw conveyor to be deposited at some remote point for disposal.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

I. An apparatus for depithing fibrous vegetable materials comprising, in combination:

A. a vertically disposed generally tubular housing,

B. means for separating the fiber from the pith portion of said vegetable materials comprising a rotor carrying outwardly projecting hammers supported for rotation about a vertical axis within said housing,

C. screening means surrounding said rotor and defining with said housing a pith chamber,

1. said screening means having opening therethrough of a size permitting passage of said pith into said pith chamber while substantially blocking passage to said fibers,

D. means forming a gravity-fed fiber discharge chute having an entrance centrally disposed below said rotor and communicating with said housing below said rotor for conveying the separated fiber out of said housing,

E. means forming two gravity-fed pith discharge chutes disposed laterally on opposite sides of and separate from said fiber discharge chute and each having an entrance communicating with said pith chamber for conveying the separated pith out of said housing, and

F. a tentlike baffle structure having two converging sloping sides and disposed in said apparatus below said pith chamber, said sloping sides being directed downwardly toward opposite ones of said entrances of said pith discharge chutes.

2. Apparatus as defined in claim 1 wherein said sloping sides are each disposed at an angle of about 50 to about 60 from horizontal.

3. Apparatus as defined in claim 1 including conveyor means for carrying said pith and said fiber from the respective discharge chutes therefor.

4. Apparatus as defined in claim 3 wherein said conveyor means includes a fiber conveyor, a pith conveyor at a position remote from the bottom of each pith discharge chute, and separate substantially horizontal conveyor means at the bottom of each said pith discharge chute for carrying said pith to said remote pith conveyor.

5. Apparatus as defined in claim ll including gravity feed means for introducing said vegetable materials into said housmg.

6. Apparatus as defined in claim I including shielding means surrounding said housing in the area of said rotor to shield operators from objects accidentally ejected therefrom.

7. Apparatus as defined in claim 1 including an access door opening into said fiber discharge chute, and means holding said opened door in a horizontal plane to substantially close said fiber discharge chute to prevent loss of tools or parts and to provide a platform for inspection and repair of said ap paratus.

8. Apparatus as defined in claim I wherein said rotor is suspended in said housing in a drive shaft, said drive shaft being supported in a shaft barrel secured to the apparatus housing, and including a plurality of stiffening ribs secured axially to said shaft barrel and mounted to said housing to maintain said rotor centrally positioned in said housing while offering minimal obstruction to the passage of materials therethrough.

9. A gravity-fed apparatus for depithing fibrous vegetable materials comprising, in combination:

A. a vertically disposed generally tubular housing,

B. means for separating the fiber from the pith portion of said vegetable materials comprising a rotor carrying outwardly projecting hammers, said rotor being suspended by a drive shaft within said housing and supported for rotation about a vertical axis,

C. screening means surrounding said rotor and defining with said housing a pith chamber,

1. said screening means having openings therethrough of a size permitting passage of said pith into said pith chamber while substantially blocking passage to said fibers,

D. a substantially vertically oriented fiber discharge chute centrally disposed in and having an entrance communicating with said housing below said rotor for conveying the separated fiber out of said housing,

E. a pair of substantially vertically oriented pith discharge chutes disposed laterally of and separate from said fiber discharge chute, each said chute having an entrance communicating, without obstruction, with said pith chamber, and

F. baffle means comprising a tentlike structure having two converging sloping sides each disposed at an angle of about 50 to about 60 from horizontal, said structure being disposed in said apparatus below said pith chamber with the sloping sides thereof directed downwardly toward the entrances to said pith discharge chutes to divert the pith falling from said pith chamber into said pith discharge chutes.

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Claims (8)

1. 2. Apparatus as defined in claim 1 wherein said sloping sides are each disposed at an angle of about 50* to about 60* from horizontal.
2. 3. Apparatus as defined in claim 1 including conveyor means for carrying said pith and said fiber from the respective discharge chutes therefor.
3. 4. Apparatus as defined in claim 3 wherein said conveyor means includes a fiber conveyor, a pith conveyor at a position remote from the bottom of each pith discharge chute, and separate substantially horizontal conveyor means at the bottom of each said pith discharge chute for carrying said pith to said remote pith conveyor.
4. 5. Apparatus as defined in claim 1 including gravity feed means for introducing said vegetable materials into said housing.
5. 6. Apparatus as defined in claim 1 including shielding means surrounding said housing in the area of said rotor to shield operators from objects accidentally ejected therefrom.
6. 7. Apparatus as defined in claim 1 including an access door opening into said fiber Discharge chute, and means holding said opened door in a horizontal plane to substantially close said fiber discharge chute to prevent loss of tools or parts and to provide a platform for inspection and repair of said apparatus.
7. 8. Apparatus as defined in claim 1 wherein said rotor is suspended in said housing in a drive shaft, said drive shaft being supported in a shaft barrel secured to the apparatus housing, and including a plurality of stiffening ribs secured axially to said shaft barrel and mounted to said housing to maintain said rotor centrally positioned in said housing while offering minimal obstruction to the passage of materials therethrough.
8. 9. A gravity-fed apparatus for depithing fibrous vegetable materials comprising, in combination: A. a vertically disposed generally tubular housing, B. means for separating the fiber from the pith portion of said vegetable materials comprising a rotor carrying outwardly projecting hammers, said rotor being suspended by a drive shaft within said housing and supported for rotation about a vertical axis, C. screening means surrounding said rotor and defining with said housing a pith chamber,

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