US3077272A

US3077272A - Cell feeder

Info

Publication number: US3077272A
Application number: US856759A
Authority: US
Inventors: Reinhall Rolf Bertil
Original assignee: Defibrator AB
Current assignee: Valmet AB
Priority date: 1958-12-11
Filing date: 1959-12-02
Publication date: 1963-02-12
Anticipated expiration: 1980-02-12

Description

Feb. 12, 1963 R. B. REINHALL 3,077,272

CELL FEEDER Filed Dec. 2, 1959 3 Sheets-Sheet 1 INVEN TOR.

Feb. 12, 1963 R. B. REINHALL 3, 7

CELLFEEDER Filed Dec. 2, 1959 3 Sheets-Sheet 3 Fig.3

INVEN TOR.

BY Q j m Q 6.4.2,, & QWMW v United States Patent 3,677,272 CELL FEEDER Rolf Ber-til Reinhaii, Lidingo, Sweden, assignor to Alitiebolaget Befibrator, Stockholm, Sweden, a corporation of Sweden Fiied Dec. 2, 1959, der. No. 856,759 Cliaims priority, appiication Sweden Dec. 11, 1958 7 Claims. (6i. 2i4'--17) This invention relates to a feeder apparatus.

More particularly this invention relates to a cell feeder intended for feeding materials to a desired place at a predetermined rate.

Still more particularly this invention relates to a cell feeder for feeding solid material at a predetermined rate and of the kind comprising a driven rotor mounted in a casing and provided with one or more pockets or chambers adapted during rotation of the rotor to communicate alternately with at least one inlet and at least one outlet in the casing and to convey material therebetween.

The cell feeder is in general intended for the transport of wood chips, straw, bagasse or similar cellulose-containing stuff between places subjected to different pressures. One important field of use of the invention comprises cookers or similar apparatus for cellulose-containing stuff within which a steam pressure of, for example, between 6 and 12 kgs. per square centimeter prevails, the stuff being introduced into the cooker by means of the cell feeder. Obviously, the reverse case may apply, that is, feeding from a place under high pressure to a place under a lower pressure.

Cell feeders of this kind are subjected to relatively great wear of the sealing surfaces arranged between the rotor and the surrounding casing and in order to compensate for such wear these surfaces have been made of conical form so as to aliow subsequent adjustment to be made by axial displacement of the rotor. The wear causes unequally distributed grooves or cavities to be formed in the surfaces and such cavities naturally remain after the adjustment and as a result a varying free space remains between the surfaces which to a high degree destroys the efiect of the adjustment.

Bushes have also been employed when the sealing surfaces were of cylindrical form, but this arrangement does not allow any compensation for wear. In such a case the only possibility of adjustment of the rotor consists in the displacement of th rotor to a more or less eccentric position with respect to the surrounding cylindrical surface of the casing, in such manner as to provide play between the surfaces which is less at the high pressure side than at the lower pressure side, for example. This adjustment does not constitute any real solution of the problem of leakage and moreover the free space between the surfaces attains a wedge shape in a peripheral direction thereby providing a danger of stufibecoming jammed between the surfaces.

One main feature of the invention is to eliminate the drawback inherent to the cell feeders hitherto known by providing a cell feeder of the kind referred to which permit compensation for wear in an easy and reliable manner.

According to one main feature of the present invention a cell feeder of the kind set forth includes jaws mounted on parts of the casing located between the inlets and outlets, and formed on their side facing the rotor to conform to the shape of the rotor and being adapted to be displaced radially relatively to the rotor. With such a construction the jaws may be adjusted without necessitating any disassembly of the feeder so as to maintain the free space between said jaws and the rotor at a size favorable from the view of minimizing leakage.

According to another main feature of the invention the 3,@77,Z?Z Patented Feb. 12, 1963 ice the outlet.

Further objects, features and advantages of the invention will become apparent from the following description, considered in connection with the accompanying drawings, which form part of this specification and in which:

FIG. 1 shows a longitudinal section taken along the line I--I of FIG. 2 through a cell feeder constructed according to the invention.

FIG. 2 shows a transverse section along the line II-II of FIG. 1.

FIG. 3 is a plan view of part of the cell feeder shown partly in section along the line III-III of FIG. 2 and on a larger scale.

FIG. 4 shows part of a cell feeder constructed according to a modified embodiment in section similar to that shown in FIG. 1.

FIG. 5 shows a section through part. of a cell feeder constructed according to a further modified embodiment.

-In the various figures the same reference numerals are used to denote equivalent parts.

Referring to FIGS. 1 to 3, reference numeral 10 denotes a casing enclosing a rotor 12 provided with journals 14 mounted in bearings 16, which in turn are supported by head rings 18 and 2% The outer rings denoted by 20 are secured by means of bolts 22 to the casing and by means of bolts 24 to the inner ring 18 which latter has an outer diameter slightly less than the diameter of the cylindrical outer face 26 of the rotor 12. The rotor 12 is caused to rotate by means of a power source (not shown) such as an electric motor associated with one or other of the journals 14.

The cylindrical surface 2.6 of the rotor is formed with pockets or chambers 28, the number of which in the embodiment shown is three and which during rotation of the rotor are alternately broug .t into communication with an inlet opening 30 and with an outlet opening 32 provided in the casing 10. The upper opening 3% may communicate with a supply hopper for wood chips or the like which thus fall down into the chamber 28 when these are located opposite the opening 3%. The rotor rotates clockwise as viewed in PEG. 2 and the chip material is conveyed to the lower opening 32 which communicates with a cooker within which prevails, for example, a relatively high steam pressure. The capacity of the cell feeder depends inter alia on the speed of rotation of the rotor which may, for example, amount to 20 revolutions per minute.

Between the two

openings

36 and 32 the casing it is formed adjacent the rotor periphery with. preferably rectangular cavities 34 which contain jaws as. The cavities 34 are sealed by plates 38, secured by means of bolts 40 to the casing It). The jaws are adjustable within the cavities 34 in a radial direction. The cylindrical inner surfaces 42 of the jaws 3d, which conform to the surface 26 of the rotor, may be arranged with free play relatively to the rotor, said play being in size of the order of 0.05 to 0.1 mm. The jaws 36 are adjusted and fixed in a desired predetermined position in the embodiment shown in FIGS. 1 to 3 by means of threaded sleeves 4'4 and screws 46 in threaded engagement with the plate 33 and'the jaw 36, respectively.

Provided adjacent the cylindrical surface 26 of the rotor and located at each end thereof axially beyond the jaws "36 are packings 48 inserted into annular grooves formed between the rotor and the casing 10. The packings are under pressure exerted by annular glands or the like St) which are pressed inwardly by screw bolts 52 in threaded engagement with the head rings 20. By means of the glands and the bolts the packings are held pressed against the base of the grooves in order to prevent leakage along this path from the high pressure side to the low pressure side of the feeder. Renewal of a packing may be effected without removing any member other than the ring 20, by unscrewing the

bolts

22 and 24. Oil is supplied to the stuffing box containing the packing from a pressure oiler (not shown) through pipes 54.

The rotor 12 formed on its outer surface 26 with a layer of hard metal may be arranged with an inter'space or play of 2.0 mm, for example, with respect to the cylindrical surface of the casing. This interspace is thus substantially larger than the play between the rotor and the jaws 36 and exceeds the value of any deflection of theroto'r due to the effect of the higher pressure acting from below.

The jaws 36 are fitted with sealing members or packings 56 arranged along three of the. sides of therectangular cavities. The fourth side, located adjacent the inlet 30, is thus without such sealing member. The sealing members 56 are tightened by means of screws 58 acting on glands 60. It is advantageous to cause the packings 48 and the sealing members 56 to contact with another at their parts located'adjacent the section line III-III shown in FIG. 2 as illustrated on FIG. 3.

The jaws 36 are provided with drainage slots 62 located preferably adjacent the central transverse plane of the rotor and varying in function depending on the direction of rotation of the rotor; On that side where the pockets 28 with their content of chip material are moving downwardly, the slots 62 act to drain off the steam or gas leaking in an upward direction between the jaw'and the rotor from the pressure vessel connected to the outlet 32. Thus this steam or gas is prevented from penetrating upwardly to the inlet opening 30 where it would tend to disturb the feeding operation.

On that side where the pockets 28 are moving upwardly, the slot or slots 62 drain off that amountof gas or steam present in said pockets after their communication with the lower outlet has been interrupted. The steam or gas escapes through outlets 64- mounted on the plates 38 and may then pass to a centrifugal separator for separation of any feed stuff entrained with the steam or gas.

The cell feeder operates in the following manner: Stuff or material such as wood chips is supplied to the inlet opening of the feeder through a hopper 65 (FIG. 2) from a storage bin (not shown). Between the bin and the opening 39 may be arranged a feeder device having a vibrator (not shown) in its base. The chips fall down into the particular pocket 28, which at that moment lies below the opening 30, and are conveyed by the rotor towards the outlet 32 where the higher pressure prevails. During the rotation of the rotor any excess material is scraped off by the jaw on that side where the filled pocket is moving downwardly. It is preferred to adjust this jaw so as to cause it to lie nearer the rotor at its upper part thus avoiding any wedging action by possibly entrained material between the rotor and the jaw. Such adjustment is attained by means of the

screw elements

44 and 46 which can be threadably operated to produce wedgeshaped spacing between each jaw and the rotor, with such spacing increasing in size in the direction of rotation of the rotor.

The opening or outlet 32 in the illustrated embodiment communicates with a cooker wherein a relatively high pressure prevails. The slots 62 separate off steam or gas leaking out upwardly on the side where the stuff is being fed downwardly. On the side where the empty pocket moves upwardly the pocket is entirely cut off from the outlet 32 before it comes into communication with a slot 62 thus causing the volume of steam or gas present in the pocket to expand and to escape through the outlet 64. In this case the minimum spacing of the rotor from the jaw should be located at the lower edge of the jaw.

The embodiment shown in FIG. 4 differs from the preceding one mainly by the provision of a stationary sealing ring 66 located in a recess 68 formed on each end face of the rotor 12. The plane lateral face of the sealing ring is maintained with a suitably small spacing relatively to the plane surface 70 of the rotor by means of threaded sleeves 72 and lock screws 74. The sleeves 72 are threaded into the head ring 20. Disposed between the casing 10 and the sealing ring 66 are packings 76 which are tightened by annular glands 78 and screws 80. At the radially inner side of the sealing ring 66 are disposed annular packings 82 which are tightened by screws 84 through annular glands 86. Oil is supplied to these packings through a distributor ring 88. The packings 82 which differ from the. packings 76 by their disposition between members rotating relatively to one another, are subjected around the circumference of the rotor to the same or substantially the. same pressure difference. Since the packings 82 are located at a smaller radius than the. packings 48 in the preceding embodiment the peripheral speed is lower and thereby the life of the packings increased.

If desired the jaws 36 may be kept pressed against the rotor in the manner shown in FIG. 5. Arranged between the jaw 36 and a support 96 are cup springs 92 which are compressed by means of a threaded sleeve 94 threaded into the plate 38, the parts being locked by means of a bolt 96.

While several more or less specific embodiments of the invention have been described it is to be understood that this is for the purpose of illustration only and that the invention is to to be limited thereby but its scope is to be determined by the appended claims.

What I claim is:

l. A cell feeder for solid material comprising, a casing containing a driven rotor provided with pockets, the easing having an inlet and an outlet with which said pockets alternately communicate during rotation of the rotor, the casing being provided in its sides between the inlet and outlet with diametrically opposite openings of rectangular form, diametrically-opposite jaws mounted in said openings, the jaws conforming in rectangular shape to the openings and being adjustable therein toward the rotor in a manner to cause a small wedge-shaped spacing to appear between the face of each jaw and the rotor, each jaw having an arcuate face disposed toward the rotor, said arcuate faces facing toward one another with the rotor disposed between them, said arcuate faces having a surface area greater than one-half of the circumferential area of the rotor.

2. A cell feeder for interior super atmospheric pressure and preferably for solid material comprising, a driven rotor, a casing in which the rotor is mounted, said casing having an inlet and an outlet, said rotor being provided with pockets or chambers adapted during rotation of the rotor to communicate alternately with the inlet and the outlet, the casing having diametrically opposite separate recesses located between the inlet and the outlet, a jaw fitting into each of said recesses, the jaws being formed on their side facing the rotor with a surface conforming to the shape of the rotor, covers on the outside of the recesses over the jaws, screw means mounted in said covers and adapted to displace the jaws against the rotor to compensate for wear, the screw means being so positioned as to adjust each jaw in a manner to result in a small wedge-shaped spacing being formed between each jaw and the rotor increasing in the direction of rotation ofthe rotor.

3. A cell feeder according to claim 2 which includes packings adapted to be tightened from outside of the casing, said packings being disposed at each end around the circumference of the rotor, and additional packings arranged along a number of sides of the jaws and axially inwardly of said circumferential packings.

4. A cell feeder according to claim 2, in which the peripheral surface of the rotor is of cylindrical shape and is arranged with free play relatively to the casing, said play being larger than the greatest spacing between the rotor and the jaws.

5. A cell feeder according to claim 2, in which spring means are disposed between said screw means and the aw.

6. A cell feeder according to claim 2, which includes draining slots extending through the jaws for removal of gaseous medium or material penetrating between the jaws and the rotor or entrained with the pockets of the rotor, the covers each having an outlet for the transport of said medium or material out of the feeder.

7. A cell feeder according to claim 2 in which recesses formed in the ends of the rotor contain stationary sealing rings having a plane annular face adjustable towards and away from a corresponding surface formed on the rotor and sealed on their cylindrical inner and peripheral outer face with respect to the rotor and to the interspace between the rotor and casing, by means of packings which are adjustable from outside of the casing.

References Cited in the file of this patent UNITED STATES PATENTS 1,327,540 Fool rs Ian. 6, 1920 1,382,371 McClimon et a1. June 21, 1921 1,432,953 Berry Oct. 24, 1922 1,900,453 Morrow Mar. 7, 1933 FOREIGN PATENTS 338,413 Germany June 17, 1921 809,184 Germany July 23, 1951

Claims

1. A CELL FEEDER FOR SOLID MATERIAL COMPRISING, A CASING CONTAINING A DRIVEN ROTOR PROVIDED WITH POCKETS, THE CASING HAVING AN INLET AND AN OUTLET WITH WHICH SAID POCKETS ALTERNATELY COMMUNICATE DURING ROTATION OF THE ROTOR, THE CASING BEING PROVIDED IN ITS SIDES BETWEEN THE INLET AND OUTLET WITH DIAMETRICALLY OPPOSITE OPENINGS OF RECTANGULAR FORM, DIAMETRICALLY-OPPOSITE JAWS MOUNTED IN SAID OPENINGS, THE JAWS CONFORMING IN RECTANGULAR SHAPE TO THE OPENINGS AND BEING ADJUSTABLE THEREIN TOWARD THE ROTOR