US2304326A - Reduction of fibrous materials - Google Patents

Description

1386- 1942- J. B. ADAMS ErAL REDUCTION OF FIBROUS MATERIALS Filed June 7, 1940 Jamal: 8. Adam andflolandflflelspasg JNVENTORS D66. 8, 1942. ADAMS ETAL 2,304,326

REDUCTION OF FIBROUS MATERIALS Filed June 7, 1940 2 Sheets-Sheet 2 Mgmum m Jo qpizfl Adamy and flalaad B. Begmss,

INVENTORS BY J MMQL.

Patented Dec. 8, 1942 p 2,304,326 REDUCTION or rmaoos MATERIALS Joseph B. Adams, Norwood, and Roland B. Respess, Wickford, R. L, assignors to Respats Ina, Cranston, R. L, a corporation of Rhode Island Application June 7, 1940, Serial No. 339,288

6 Claims.

The invention herein disclosed relates to the reduction of wood and other fibrous materials.

Particularly the invention relates to reducing mills in the nature of those covered by R. B. Respess, Patent 1,976,297, of October 9, 1934, in which reduction is effected by the cooperative K rubbing action of heavy rollers turning in a rotating annular form of trough or bed.

The present invention is especially concerned with the development of certain features of the Respess mill to improve-the feeding of the chips or other material to the mill, to provide more uniform control and treatment of the material and to facilitate removal ,of the reduced material from the mill:

Special objects of the invention are to accomplish more thorough and uniform reduction to the fibrous state; to obtain such results with the lowest possible power requirements and time of treatment and to obtain a better fibrous product having desired characteristics as to strength and other factors and well suited to various uses, such as for wall and insulating board, hard pressed board and the like.

Other desirable objects-and the novel features of invention by which the objects are attained are hereinafter set forth'or will appear in the course of the following specification.

The drawings accompanying and forming part of the specification illustrate certain practical embodimentsof the invention.

Structure however may be modified and changed as regards the immediate disclosure, all within the true intent and scope of the invention, as will appear from the following description and the claims broadly covering the invention.

Fig. l is a side elevation of one of the machines, with parts broken away and appearing in section.

Fig. 2 is a plan view illustrating the rotating bed, reducing rolls and the scrapers which are reversible to direct the reduced material inward to the central discharge throat, this view being taken on substantially the plane of line 2--2 of Fig. 1.

Fig. 3 is a broken part sectional plan view of the machine.

Fig. 4 is a broken detail view illustrating the cam means for reversing the scrapers.

Fig. 5 is a brokenpart sectional detail illustrating simple gravity discharge of thematerial, instead of by suction fan, as first shown. I

Fig. 6 is a similar view, illustrating removal of treated material by hydration and flushing.

The machine here illustrated incorporates features of the patent identified, including the annular trough or bed I, driven through gearing 8, by motor 9, and the reducing rolls l0, ll, retained in axially offset relation and having the cylindrical inner portions l2, riding the inner annular flat portion l3, of the bed and the inclined convergent outer end portions l4, cooperating with the correspondingly or similarly upwardly inclined outer confining wall or rim i5 of the rotary bed.

One of the important distinguishing features of the present invention is that the material after A treatment, is withdrawn down through the bottom, at the center of the trough or pan.

In Figs. 1 and 4, the rotating trough is shown as formed at the center with a downwardly directed circular spout or throat l6, overlying and discharging into a stationary chamber H, in the central base structure I8 of the machine. A conduit I9 is shown extending from this chamber down through the hollow base structure.

Various means and methods may be employed for withdrawing and carrying off the reduced fibrous material.

illustrated, involving provision of a suction fan 20, having its intake connected with the downfiow pipe [9, and provided at the pressure side with a transport pipe 2|, extending to a storage bin or the like.

To prevent concentration of the downpull right over the center and to make the air flow inwardly from the edges over the bottom of the pan, thus to sweep the material more or less uniformly toward the central outlet, a deflector 22, is shown supported above the bottom, directly over the discharge throat and of somewhat larger diameter than the outlet.

Fig. 5 illustrates a simple gravity discharge, with a belt conveyor 23, positioned to receive and carry off the material droppedfrom the bottom of pipe i9.

Fig. 6 illustrates a hydraulic form of discharge wherein a centrally disposed pipe 24, discharges a stream of water, with volume regulated by'valve 25, downwardly into the throat, thus to hydrate the reduced material and to flush it into a trough or flume 26, atthe footof pipe l9 and which may carry the hydrated material off to a suitable diameter.

or direct the water as may be found best for desired results. This pipe is shown as used for supporting the air flow directing cap 22, enabling the machine to be readily converted, if desired, from one system of discharge to the other.

For most purposes, the air removal form of discharge may be preferred, particularly because this has a beneficial effect on the fibers tending to more thoroughly separate and spread the small fibrous masses. In this more or less fluifycondition, the .flbers will hydrate more rapidly and more thoroughly, which condition is particularly desirable, if the reduced material is to be given a cooking treatment.

In cases where immediate hydration is desirable, the water flow'form of discharge, such as indicated in Fig. 6, may be preferred. 1

The machine is adapted to either continuous or batch operation. The later may be preferred as enabling better control of the time of treatment and as providing a, more uniform or average product.

In the, illustration, wood chips or other base material are supplied to the machine in batches from a hopper 21, receiving the material from a belt conveyor 28, and delivering it in predetermined charges to trough 29, in which a spiral conveyor 30, carries it to an inclined chute 3 I which delivers the material, at a rate determined by the feed screw into the upwardly inclined rim portion of the pan in advance of one of the rollers (i i). This entering supply of material may be divided into two streams or as many streams as there are rollers, thus to start both or all rollers operating on the material at the same time.

As now designed and operated, the machine 2,304,326 provided on the lower end of pipe 24, to spray the discharge throat. This cam is shown as acting on the roll 42, at the upper end of lever 43,

Y which is pivotally supported at 44, and has a sliding connection at 45, with the scraper shift link 40. This scraper cam is suitably driven, as by sprocket chain connections 46, and gear reduction box 41, from motor 28, Fig. 1.

Operation In a typical operation, green chips, such as of southern pine steamed for one hour at 70 lbs. pressure and containing approximately 100% by weight, water are supplied in a charge of about lbs., the feed mechanism 21-3l, Fig. 1, being operated to deliver such charge quickly but in a substantially uni-form stream into the revolving pan in front of roller H, and preferably at a point between the convergent and coacting inclined end of the roller and inclined outer wall of the pan. g

The rollers l0, ll, under control of the yokes 49, by which they are journalled, can rise under the lifting efiect of the wood chips passing under them and at the same time move sidewise to exert pressure against the inclined or curved side wall of the pan. By reason of the off center and non-radial mounting, the rollers exert a rubbing and wiping action, thus tending to rub the fiber bundles apart, with a minimum of cutting and breaking.

Ordinarily a 2 to 4 minute period of reduction is sumcient and in the example under consideration, 4 minutes may be taken as the complete cycle, with a 3% minute run and /2 minute allowed for emptying and loading.

During the run or active reduction period, the movable scrapers may be positioned as shown in full lines, Fig. 2, to turn the chips over and to is of large size, the rollers being approximately.

6000 lbs. each and the pan being about "7 feet in At a speed of 60 R. P. M. the centrifugal action in this pan is sufficient to carry the material continuously outward toward the inclined rim of the pan, more or less in a path as indicated at 50, in Fig. 2.

To control this centrifugal travel of the stock and to lift, turn and spread the material and direct itto where it will be best and most efii-- ciently acted upon by the rolls and the pan, scrapers or deflectors are preferably provided, which may be adjusted and operated to best effect such results. 1

In Fig. 2 there are shown three such scrapers 32, 33, 34, pivotally mounted in radially adjustable position over the pan at 35, 36, 31. These may be all at one side or associated with one roll or be at difierent sides of the pan and related to each or different rolls. Also they may be movable or fixed, or some movable and some fixed as in the illustration, where scrapers 32,

33, 34, are shiftable about their axes and another illustration, Fig. 4, a cam 4|, is provided to reverse the movablescrapers at a predetermined time and also at a predetermined'rate, to reverse the outward flow of stock under centrifugal action and to more or less gradually turn it back lift and throw them up and outward toward the curved rim of the pan, where the inclined ends of the rollers will push them. down and apply a form of attrition against the curved side wall of the pan. The scrapers, assisted by or assisting centrifugal force thus during. the active period, force the material outwardly and keep it continually within the range of action of the rollers.

At the end of the active reduction period, say 3 /2 minutes, the rotating pan is slowed down either automatically or under hand control and the position of the scrapers altered to direct the reduced material to the discharge opening in the center of the pan. In the example, a time switch controls the motor 9, to automatically reduce the rotation from 60 to 30 R. P. M. at the end of the 3%; minute period and at this time, the cam 4|, operated from motor 48, turns the scrapers 32,

33, 34, to more or less gradually reverse the travel of the chips and send them in a more or less uniformfiow toward and to the center discharge outlet. The reduced speed of'rotation so reduces the effect of centrifugal force that the scrapers are enabled to quickly and smoothly accomplish this clearing of the bottom of the pan.

I1 air removal is employed, as in Fig. 1, the suction fan may be run continuously or about half of each cycle.

The air, drawn radially inwardly over the bottom of the pan, beneath the deflector 22, by the fan 20, sweeps the reduced fibrous matter down through pipe l9, and in so doing, separates,

. spreads and finds the material, thus rendering it more open to penetration and hence better conditioned for subsequent hydration, cooking or in a substantially uniform flow, inwardly toward the like.

If immediate hydration is desired, then the water flow removal illustrated in Fig. 6 may be used, in which event, valve 28, may be operated automatically or. by hand to flush the material down through pipe is, into a fiume 28, which may run to astock chest.

As the pan empties the scrapers are returned by cam ll, to their first control position, the

time switch or other. means automatically brings the pan up to the normal 60 R. P. M. speed and another batch of wood chips is dropped or flowed into the pan from the batching hopper.

The reduced wood fiber, for most purposes, is placed in stock chests containing agitators and mixed with the proper amount of water and made ready to be pumped to an attrition mill, paper beater or other refiner to receive final conditioning for the purpose intended, such as wallboard, insulating board, sheathing, hard pressed board, or the like.

From the attrition mill, paper beater or other refiner,. the prepared pulp may be stored in stock chests ready for the board making machine.

In the preparatory steaming operation, the wood 'chips'may be conveyed from the chipper to a Globe rotary steamer and steamed for sufficient time to absorb up to about 80 to 100% of moisture. This steaming operation is important as providing a much softer and easier worked fiber than can be produced with unsteamed wood chips.

With batch operation as described, the fibrous material may be worked for the length of time found best for the results desired. No free water is required. While southern pine has been mentioned as a source of supply, northern spruce chips and other fibrous sources may be used, the machine by reason of the rubbing and wiping action of the rollers in the pan and particularly when timed by batch operation, producing a superior grade of fiber possessing unusual strength,

' flexibility and other desirable qualities.

In view of the broad scope of the invention, the terms employed have been used in a descriptive rather than in a limiting sense, except as the intent to limit may appear or possibly be required by state of the prior art. Thus in the claims where a roller, is mentioned, it should be understood that this is intended to include a structure in which more than one roller may be present.

What is claimed is:

1. A mill for reducing fibrous material, comprising a rotating, horizontally disposed annular bed, id bed having a flat annular bottom pro-. vide with a flush discharge outlet at the center of the same and'with anupwardly inclined wall at the outer rim, annular bearing means for said bed located below the fiat bottom of thebed and in the annular space between the discharge outlet at the center of the bed and the wall at the outer rim of the bed, leaving the space below the central outlet open for downward discharge of material reduced in the bed, means for rotat ing said annular bed on said bearing means, reducingrollers rotatably disposed above said bed on horizontal axes and having correspondingly inclined end portions for enacting with said up- -wardly inclined outer wall or the bed, means loosely confining said rollers to self-adjusting travel across the annular flat bottom of the rotating bed between said upwardly inclined outer wall and said central discharge outlet, means for effecting feeding of material to be reduced in front of said rollers, means for effecting traverse of sumciently reduced material over the flat bottom of the bed inwardly away from said rollers to said central discharge outlet and means below said rotating annular bed for carrying away the reduced material traversed from said reducing rollers inwardly to said central discharge outlet.

2. A mill for reducing fibrous material, comprising a rotating, horizontally disposed annular bed, said bed having a flat annular bottom provided with a flush discharge outlet at the center ofthe same and with an upwardly inclined wall at the outer rim, annular bearing means for said bed located below the fiat bottom of the bed and in the, annular space between the discharge outlet at the center of the bed and the wall at the outer rim of the bed,,leaving the space below the central outlet open for downward discharge of material reduced in the bed, means for rotating said annular bed on said bearing means, reducing rollers rotatably disposed above said bed on horizontal axes and having correspondingly inclined end portions for coacting with said upwardly inclined outer wall of the bed, means loosely confining said rollers to self-adjusting travel across the annular fiat bottom of the rotating bed between said upwardly inclined outer wall and said central discharge outlet, means for effecting feeding of material to be reduced in front of said rollers, means for effecting traverse of sufiieiently reduced material over thefiat bottom of the bed inwardly away from said rollers to said central discharge outlet, means below said rotating annular bed for carrying away the reduced material traversed from said reducing rollers inwardly to said central discharge outlet, said last mentioned means including a stationary pipe extending downwardly from the open space within said annular bearing means and an annular lip at the edge of said central discharge outlet directed toward said stationary down pipe and prising a rotating, horizontally disposed annular bed, said bed having a flat annular bottom provided with a flush discharge outlet at the center of the same and with an upwardly inclined wall at the outer rim, annular bearing means for said bed located below the fiat bottom of the bed and in the annular space between the discharge outlet at the center of the bedand the wall at the outer rim of ,the bed, leaving the space below the central outlet open for downward 'discharge of material reduced in the bed, means for rotating said annular bed on said bearing means, reducing rollers rotatably disposed above said bed on horizontal axes and having correspondingly inclined end portions for coacting with said upwardly inclined outer wall of the bed, means loosely confining said rollers to self-adjusting travel across the annular fiat bottom of the rotating bed between said upwardly inclined outer wall and said central discharge outlet, means for effecting feeding of material to away from said rollers to said central discharge outlet, meansbelow said rotating annular bed for carrying away the reduced material traversed from said reducing rollers inwardly to said central discharge outlet and a stationary deflector above said central discharge outlet in the rotating bed for controlling flow oi air across the annular fiat bottom to said central discharge outlet.

4. A mill for reducing fibrous material, comprising a rotating, horizontally disposed annular bed, said bed having a fiat annular bottom provided with a flush discharge outlet at the center of the same and with an upwardly inclined wall at the outer rim, annular bearing means for said bed located below the flat bottom of the bed and in the annular space between the discharge outlet at the center of the bed and the wall at the outer rim of the bed, leaving the space below the central outlet open for downward discharge of material reduced in the bed, means for rotating said annular bed on said bearing means, reducing rollers rotatably disposed above said bed on horizontal axes and having correspondingly inclined end portions for coacting with said upwardly inclined outer wall of the bed, means loosely confining said rollers to self-adjusting travel across the annular fiat bottom of the rotating bed between said upwardlyinclined outer wall and said central discharge outlet, means' for efiecting feeding of material to be reduced in front of said rollers, means for eflecting traverse or suflieiently reduced materialover the flat bottom of the bed inwardly away from said rollers to said central discharge outlet, means below said rotating annular bedior carrying away the reduced material traversed from said reducing rollers inwardly to said central discharge outlet, a substantially centrally located pipe for discharging liquid downwardly toward said central discharge outlet and a substantially horizontally extending deflector carried by said pipe.

5. A mill for reducing fibrous material, comprising a rotating, horizontally disposed annular bed, said bedhaving a flat annular bottom provided with a flush discharge outlet at the center of the same and with an upwardly inclined wall at the outer rim, annular bearing means for said bed located below the fiat bottom .of the bed and in the annular space between the discharge outlet at the center of the bed and the wall at the outer rim of the bed, leaving the space below the central outlet open for downward discharge of material reduced in the bed,

means for rotating said annular bed on said bearing means, reducing rollers rotatably disposed above said bed on.horizontal axes and having correspondingly inclined end portions for coacting with said upwardly inclined outer wall of the bed, means loosely confining said rollers to self-adjusting travel across the annular fiat bottom or the rotating bed between said upwardly inclined outer wall and said central discharge outlet, means for effecting feeding oi material to be reduced in front oi said rollers, means for eiiecting traverse of suiiiciently reduced material over the flat bottom of the bed inwardly away from said rollers to said central discharge outlet, means below said rotating annular bed for carrying away the reduced material traversed from said reducing rollers inwardly to said central discharge outlet, said means for effecting traverse of material across the fiat bottom of said rotating bed including scrapers inclined in respect to flow of material carried by said rotating bed, to direct said material into said downwardly discharging'central outlet.

6. A mill for reducing fibrous material, cornprising a rotating, horizontally disposed annular,

bed, said bed having a fiat annular bottom provided with a flush discharge outlet at the center of the same and with an upwardly inclined wall at the outer rim, annular bearing means for said bed located below the fiat bottom of the bed and in the annular space between the discharge outlet at'the center'of the bed and the wall at the outer rim of'the bed, leaving the space below the central outlet open for downward discharge of material reduced in the bed, means for rotating said annular bed on said bearing means, reducing rollers rotatably disposed above said bed on horizontal axes and having correspondingly inclined end portions for'coacting with said upwardly inclined outer wall of the bed, means loosely confining said rollers to self-adjusting travel across the annular flat bottom of the rotating bed between said upwardly inclined outer wall and said central discharge outlet, means for efl'ecting feeding of ,material to be reduced in front of said rollers,

JosEPr-r B. ADAMS. ROLAND n. aEsPEss.

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