US2087559A - Stuff treatment apparatus - Google Patents

Description

July 20, 1937. c. P. TOLMAN- 2,087,559

- STUFF TREATMENT APPARATUS Origihal Filed March 28, 1934 2 Sheets-Sheet 1 INVENTOR ATTORNEYS Charles 1 fblman, BY r 0% am'awr k m c. P. TOLMAN STUFF TREATMENT APPARATUS Original Filed. March 28', 1934 Jul 20, 1-937.

2 Sheets-Sheet Z M mA s m M m ms m a Patented July 20, 1937 UNITED STATES PATENT orrlcs STUFF TREATMENT APPARATUS tion of New York Original application March 28, 1934, Serial No.

717,717. Divided and this application January 12, 1937, Serial No. 120,313

3 Claims.

The present invention relates to an improvement in apparatus for stuff treatment wherein the material to be treated is passed in fluid form or in a fluid medium through a treatment zone and there subjected to suitable forces for producing the desired change of condition.

One object of my invention, in so far as it relates to treating fibrous cellulose material for making paper, board, or the like, has been to provide apparatus for defibering and finishing the stock wherein the character and/or extent of treatment thereof may be effectively controlled to produce a. product having materially improved quality as compared to stocks treated in beaters of the Hollander or Jordan typesfor example. For a summary of more recent hypotheses bearing on cellulose treatment phenomena in paper making, I refer to a pamphlet by W. Boyd Campbell, entitled The Cellulose Water Relationship 20 in Paper Making, published 1933 by the Department of the Interior, Canada. In view of conflicting theories as to what takes place in preparing pulp for the paper or board machine,

i. e. whether the effect is chemical and therefore 2 hydration, or physical and therefore fibrillation and/or wetting or a combination of these, I employ the term finishing to designate generically the treatment applied to pulp or the like at the beater stage, it being understood, however, that 30 the term is also used by me to include analagous treatment of other substances.

In accordance with my invention, where fibrous cellulose material of suitable consistency in a fluid medium is treated, I deliver a supply of the stock under pressure into contact with a portion of the peripheral surface of a high speed rotor provided with transverse peripheral grooves. For effective operation, the feed pressure used is sufficient to overcome the centrifugal counter force developed by rotation at high speeds, i. e. of the order of 5000 feet per minute or more. A qiiantity of stock is thus forced into each rotor groove and carried. by the rotor into a film shearing gap or treating zone preferably formed between the rotor periphery and a suitable stator or stators spaced therefrom a distance of the order of .005 of an inch or less. In this zone the entire contents of each groove are subjected to a uniformly effective defibering and finishing ac- 0 tion under pressure and then discharged from the treatment zone with sudden or material decrease of pressure. Characteristics of this mode of operation are, in .general, that for a. given rotor speed the capacity or rate of throughput for stock of given consistency varies with the feed pressure; that for a given feed pressure the character and/or degree of finishing varies with the zone or gap pressure and/or the extent or length of the zone or gap'; that the amount of cutting or shortening of the fibres is uniformly 5 negligible compared to the amount of fibrillation and/or wetting or hydration, whatever the feed and/or gap or zone pressures employed; and that defibering, i. e. the breaking down of bundles of fibers into smaller groups'or single fibers, is a constant factor regardless of the degree or character of wetting or hydration.

In View of the widely varying peculiarities of different kinds of stocks and the different treatment characteristics required for various ultimate products, my method further includes testing the treated material and then adjusting the feed and/or gap or zone pressure and/or length of gap or zone to increase or diminish the extent of finishing required to render the material suitable for its intended purpose. The gap or zone pressure may be adjusted by regulating the rotor speed, by increasing or decreasing pressure on the stator, or in any other suitable manner.

To summarize therefore, my invention so far as it relates generally to the treatment of fibrous materials in a fluid medium includes broadly apparatus wherein means are provided for subjecting a supply of the stock to initial or feed pressure, removing successively presented small portions of the supply from the initial or feed pressure condition toa treatment zone, and there subjecting said separated small portions simultaneously to treating forces under increased pressure to effect defibering, wetting and/or hydration, and fibrillation substantially without cutting or shortening of the fibers. If the circumstances require, a further operative step includes testing a treated portion of the material and adjusting the time of treatment and/or the feed or gap or zone pressure to change the character and/or degree of treatment.

An object of the presently considered invention has been to provide apparatus whereby trash or articles too large or refractory to be treated as above descibed are separated from the material under treatment and conveniently discharged.

This application is a division of my pending application, Serial No. 717,717, filed March 28, 1934 for Stuff treatment apparatus.

One embodiment of apparatus adapted for use in connection with the treatment or preparation of paper stock or the like is illustrated in the accompanying drawings attached to and form- 55 ing a part of, the present specification and in which- Figure 1 is a front end elevation with .outer parts thereof removed to disclose interior portions and with other structural features shown in vertical section;

Figure 2, a view partly in vertical section of a modified form of mill with a trash discharge device and shoe pressure control devices;

Figure 3, a horizontal section on the line 8-4 of Figure 2; and Figure 4 a section on the line 4-4 of Figure l.

In the machines shown in the drawings, Figure 1, a rotor I, having peripheral grooves 31, is mounted to rotate in the direction of the arrow, Figure 1, in a superstructure supported on a base 2 and is driven through shaft 8 by a motor or other power source, not shown. Shaft I is Journaled in bearings mounted in spiders I, one of which is opposite a front frame 0 and the other of which is opposite a rear frame, said frames being spaced apart by suitable means, as, at the bottom, by a casting I and at the top by a spacer 9. A tie bolt ll passes through upper portions of both frames and the spacer 0. Another tie bolt l4, Figure 1, passes through lower portions of said frames and through said casting I.

As shown in Figure 1, the mill is provided with a plurality of radially arranged stator units removably mounted between frames 6 and I and including cylinder caps ll secured thereto by bolts II passing through end portions of cylinder blocks it. Each stator unit also includes a shoe carrier i0 movable in a radial direction toward and from rotor i and having a dovetail slot ll adapted to releasably retain a shoe, as 20 or 2|. The shoe 20, hereinafter designated the first shoe, is preferably of suitable metal and fitted with a projecting nose 22. The shoes 2| may be made of wood, metal or other suitable material, ,depending on the conditions of use.

The working faces of the shoes may be continuous or plain for some purposes, or, as shown in Figure 1 may be provided with grooves 205. It has been found that with the grooved shoe a greater amount of power can be effectively applied to the same character of stock under treatment.

In the space between the first shoe 20 and the last shoe 2|, suitably formed castings provide a feed inlet chamber or passage 23, a stock discharge or outlet passage or chamber 24, and a trash discharge passage or chamber 25. The inlet chamber 23 communicates with a feed inlet opening 20 at one side of the base 2 and the discharge chamber 24 communicates with a discharge opening near the front end of the base. A drain opening in base 2 connects with the trash discharge passage 25 and also receives waste or leakage through seal ring drain passage 3| and other drain passages. A removable cover 34 closes an opening into the feed inlet chamber 23 and a removable cover 35 closes an opening into the discharge passage or chamber 24. A doctor bar 36 extends across said chamber opposite the last shoe 2| and is adjustable toward and from-the rotor periphery. Another transverse bar 38 is mounted in the feed chamber 23 opposite the first shoe 20 and is adjustable toward and from the rotor periphery. A small chamber 00 between said bars 30 and 38 connects with the drain passage 3i through openings or ducts 40.

In normal operation of a mill of the type thus far described, the furnish or material for trea't- 'eign object or substance.

ment. where it comprises up to 10% of wood pulp in water for example, is forced in a continuous supply under suitable pressure through inlet opening 26 and feed chamber 28 into contact with the grooved periphery of rotor I which, in a preferred embodiment, attains a peripheral speed of about 12,000 feet per minute. Particles of suitable size are forced by thei'eed pressure into the peripheral grooves 81 each of which, in the mill as shown in Figure 1 is around inch wide, decreasing in depth rearwardly from a maximum of approximately .08 inch near its leading edge to the land between its rear edge and the next groove and defining a substantially stream line contour of the leading face of the land which is believed to produce a combined scouring and wiping effect in operation. It will be understood that these dimensions and the shape of the grooves may be varied to meet difierent conditions of use. During rotation, each groove of the rotor. as it passes the feed chamber 28, picks up a small amount of pulp, depending on the amount of the feed pressure, which therefore determines the mlll's capacity or rate of throughput, and carries it into the treatment zone or shearing gap where it is subjected to the intended treatment, provided the material pre- ;sented is of suitable size to pass the inlet opening to said zone. In respect to any given kind of stuff, the insumciently reduced particles and foreign objects such as pieces of wire, gravel, glass, etc. and other trash therein accumulate against oradjacent to the front face of shoe 20 and, unless removed, eventually obstruct the suppLv of stock to the treatment zone.

A suitably controllable gate or valve 4|, Figure 1, mounted on a shaft 40, is interposed in an opening between the feed chamber 23 and the trash chamber 20. One end of said shaft 40 extends through a front wall of the machine and, in a hand operated embodiment, carries an operating lever not shown. As the gate 4| is rocked rearwardly against the incoming supply of material the eifective cross sectional area of chamber 23 is constricted, thus producing a correspondingly increased velocity of the stuff stream which now scours past the shoe nose 22 dislodging the trash accumulation and discharging it freely into the trash chamber 2'. This purging or cleaning eflect may be aided by -fiushing with water through a nozzle 40'. Figure 4; suitably positioned, as adjacent to the nozzle 40 at the end of pipe l2l, for example, across the face of shoe 20 and nose 22, said nozzles 40 and 48; being mounted in and extending through a block 49 carrying side plates 00, the inner edges of which are brought close to the rotor by manipulating adjusting screws II and when so positioned, oppose leakage of stock from the feed chamber. The gate 40 carries a suitable flexible contact strip 52 of rubber, rubberized fabric or the like, to provide an effective closure across the end of said gate and to prevent injury to the parts in case the gate is closed against a rigid for- The arrows and direction lines in Figure 1 indicate the course of the stuff stream when the gate is in its intermediate partly open position, suggested by dotted lines 45'. Where the gate is retracted to dotted line position 45" the feed stream is substantially shut oil and the purging or cleaning out of trash may be completed by flushing with water through said nozzle 48' if necessary or desired.

In the modified form of mill shown in Figure 2, a peripherally grooved rotor II is mounted in treatment zone or shearing gap forming relation ,7 to individually adjustable stators 62 provided with removable shoes 63. A suitably shaped casting provides a stufl inlet chamber 64 having a lateral inlet opening. Material to be treated, i. e. pulp, is fed into said chamber under suitable pressure, and subjected to treatment in the shearing gap, or between the rotor periphery and the shoes 63. The finished stock is discharged into chamber 66, portions thereof being guided by a doctor 61 supported at the end of a doctor plate 68. A discharge opening or delivery spout 69 receives and discharges the treated product from the mill.

As applied to the preparation, refining or finishing of fibrous cellulose material in paper and board manufacture, apparatus of the various types shown in Figures 1 to 3 inclusive, when operated in connection with suitable methods, provides a stock refining action which produces a high degree of wetting" in relation to the amount of cutting. For practical purposes, it may be said that the apparatus produces wetting without cutting, the reduction in fiber length being so small as to be negligible. In this respect said apparatus is free from the operating limitations inherent in machines of the Hollander and Jordan types and others in which increased wetting effeet is always accompanied by increased cutting.

As in the case of the mill last described, Figure 2, trash usually accumulates in the feed box adjacent to the rotor during operation. Clean out or purging means for this waste material include a trash discharge chamber 10 having an outlet H at one side, Figure 6, and a water inlet 12 at the opposite side. A valve or gate 13 is pivotally mounted in a suitable opening between stock inlet chamber 64 and trash discharge chamber 10, said gate having a flexible edge piece 14, as of rubber or rubberized fabric, which bears against a shoulder 15 when valve 13 is in closed position. A packing strip 16 extends across the opposite edge of valve 13 and opposes leakage past said edge and the adjacent curved wall 11. Suitable means such as the hand operated lever 41, Figure 3, may be employed to actuate valve 13. However, when valve 73 is moved toward open or dotted line position, Figure 2, the scouring effect of the stufi stream is initially confluent with the direction of rotation of rotor SI and the obstructing matter is dislodged and discharged into chamber 10 from which it is flushed out by water Jet 12 through said trash discharge outlet 1 I The specific forms and arrangements of the trash valves or gates described in this specification constitute a separate but related joint invention made by James T. Coghill and myself and form a part of the subject matter of another and separate application, Serial No. 717,718 filed March 28, 1934.

As applied to paper making and the like, the purging apparatus not only makes practical the use of continuously operating defibering, fibrillating or wetting machines for example, but also protects said machines and the quality of the ultimate board or paper product. In box board manufacture, substantial economies are effected by eliminating a considerable part of the hand sorting and cleaning of the raw waste stock. These advantages are of course additional to the novel and effective stuff finishing capabilities of the mill and the wide range of control which it affords over the extent and character of stuff treatment.

To achieve effective control over the character and/or extent of treatment of the stuil fed to the mill, each shoe carrier I 8 is mounted at the ends of rods 19 of pistons- 8! operating in cylinders of the cylinder block l6, and means are providedto controllably move said pistons and there-.

fore the shoes 2| toward and away from the treatment aone'or gap.

In the treatment of sulphite pulp, for example, this being one of many uses for which a mill embodying my improvements may be employed, feed pressures of from 5 to 35 pounds have been used with hydraulic pressures of from 30 to pounds per square inch applied to the shoes through the pistons and thence to the stuff under treatment in the treatment zone, these figures being illustrative and in no sense intended as limitations.

For most emcient operation, apparatus of the kind described will preferably be supplied with stuff by feed mechanisms capable of delivering the material into feed chamber 23 at a substans tially constant pressure. Means are also provided for adjusting such devices to feed stuif substantially constantly at different pressures within a suitably wide range. These controls relate particularly to the mill capacity or rate of throughput. So far as the feed pressure is regulatable over a wide range, the mill capacity is widely flexible and capable of satisfying different volume demands; and so far as the controls maintain a given pressure substantially constant, the capacity or throughput remains substantially uniform. In the refining, finishing or wetting of wood pulp, for example, these features are especially important, both in actual production and in their relation to economy in plant equipment.

I have found that by employing my apparatus hereinabove described in the preparation of paper stock, I have produced an intermediate product having novel properties which present material advantages in paper manufacture and the like. For example, the described treatment permits the refining, wetting, or finishing of pulp to be carried to any desired degree without cutting or reducing the fiber length, which means that hydration or wetting may be effected independently of cutting. If for any given paper machine or paper product, more cutting is needed to facilitate sheet formation after the stock has reached approximately the desired degree of wetting, this can be done by a relatively short treatment in a Jordan or other cutting machine, or the required amount of a shorter fibered pulp may be added to the run either before or after the wetting or finishing treatment.

Furthermore, my improved apparatus produces a completely defibered pulp, i. e. a finished pulp practically free of fish eyes, slivers, lumps, or other defects, as the necessary result of practically any degree of finishing treatment sufficient or suitable for paper making purposes. Pulp defects of this kind, according to known paper mill practice, are avoided or disposed of only by long and most exacting and consequently expensive beater or equivalent treatment. Some other advantages among many residing in the defibering capabilities of my apparatus are that the pulp may be finished with less prolonged previous cooking and, under proper conditions, broke may be refinished after a simple breaker treatment instead of rerouting it through heaters or other time and power consuming devices.

Numerous other advantages and beneficial results in the operation of my above described apparatus, including substantial economies in time and power, will be clearly apparent to the skilled paper maker.

I claim:- a

1. In stufl treatment apparatus, the combination of a rotor, a feed chamber opening upon a segment of the peripheral surface of the rotor, and a stator mounted to form a stufl treatment zone with said peripheral surface and having a tapered nose extending into the ieed chamber and overlying a portion of the stud treatment zone.

2. In material treating apparatus, the combination of a casing arranged to define a rotor chamber and a treating compartment having an opening connecting it with the rotor chamber, a rotor supported in the rotor chamber with its 15 periphery extending across and closing said opening, a stator in said treating compartment cooperating with the peripheral surface of said rotor through said opening to form a treatment zone, said compartment having an inlet port for admitting material thereto at the inlet end of said zone, an outlet port positioned to discharge obstructing material from said inlet end of said zone, and a nozzle for directing water against said material to facilitate its discharge through said port.

3. In material treating apparatus, the combination of a rotor, a stator cooperating with the

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