USRE22519E - Processing apparatus - Google Patents

Description

July 18, 1944. 5. DE H. MILLER ETA]. 22519 PROCESSING APPARATUS Original Filed Dec. '6, 1939 3 Sheets-Sheet l 5 12 FIE .l 23 I f 17 INVENTQRS ATTORNEYS JI-III y 1944- B. DE H. MILLER ETAL I Re. 22,519

PROCESSING APPARATUS I Original Filed Dec. 6. 1959 5 Sheets-Sheet 2 ////////K/ZI W/AAEV/Ai'EQ/flli R INVENTOR? ATTQRNEYS 1 1944. B. E MILLER ETAL Re. 22,519

PROCESSING APPARATUS 3 Sheets-Sheet 3 Original Filed Dec.

AT TORNEYS "an Reiuued July 18, 1944 PBQCESSING APPARATUS Bruce De Haven Miller and Henry .W. Bevarly,

Louisville, Ky llllml'l to The Gll'llllil' Corporation, Louil'flle, 81., a corporation of Del- No. 2,281,944, dated May s, 1942, serial No. 307,778, December a, 1939. Application reireissue May 1, 194:, Serial No. 485,400

21 Claims.

The present invention relates to an apparatus for processing liquids or semi-plastic materials, and is particularly useful in the preparation of ,paraflines, soaps. waxes, oils, fats, lard, margarine,

greases, ice cream and the like.

"One object of the present invention is to provide a new and improved apparatus of the character described for effecting efllcient and uniform change .in temperature and intimate uniform intermixing oragitation of the material processed therein.

' Another object is the character described, in which the material being processed is caused to take a .zigzag path back and forth between two heat transfer surfaces.

As a feature of the present invention, the processing apparatus is provided with internal and external drums forming an annular processing chamber therebetween, and a ported hollow shaft in said chamber carrying scrapers arranged to scrape films or layers of material from the surfaces of both drums, and directit in and out through the ports in said shaft and alternately against said surfaces. with this construction, a uniform processing of the material takes place, and none of it is permitted to short circuit through the apparatus as is the case with some types of continuous processing apparatus, or to collect in regions remote from the heat transfer surfaces.

The apparatus is provided with means whereby a suitable fluid-of the desired temperature can be applied to the outer surface of the outer drum and to the inner surface of the inner drum, so

' that the temperature of the material in the annular chamber may be held constant or changed to the desired extent. The scrapers acting on the opposed surfaces of v the heat transfer walls of the drums continuously remove iilmsor layers of the material tending to adhere to said walls and thereby'maintain emcient heat transfer as well as thoroughly agitating the material in said chamber, and prevent stratification of different constituents of a mixture, if said constituents have markedly different specific gravities.

As a further feature of the invention there is provided a novel, simple and effective means for applying a volatile refrigerant to the walls of the drums.

to provide an apparatus of of apparatus embodying the present invention,

and shows the ported shaft extending between inner and outer drums, and carrying scrapers,

Fig. 2 shows an end portion of the assembly of Fig. 1, the outer drum being in longitudinal section and the other parts in side elevation,

Fig. 3 is a perspective of the ported shaft without the scrapers,

Fig. 4 is a development of the shaft of Figs. 1, 2 and 3,

Fig. 5 is a longitudinal section through another form of ported shaft embodying the present invention, and shown without the scrapers,

Fig. 6 is a transverse section taken on line i6 of Fig. 5, and showing the inner and outer drums in dot and dash lines.

Fig. 7 is a transverse section taken on line 1-1 of Fig. 5, but showing the scrapers mounted in position, and showing the inner and outer drums in dot and-dash lines.

Fig. 8 is a transverse end section taken on line 8-8 of Fig. 5.

Fig. 9 is a longitudinal section through a com- ,plete machine, portions being broken away to show therein a ported shaft of the type shown in Figs. 5 to 8', and

Figs. 10 and 11 are transverse sections taken on lines lit-Ill and ll-ll of Fig. 9 respectively.

Referring to'Flgs. 1 to 4, the apparatus comprises a pair of stationary concentric cylindrical drums l0 and ii, forming an annular chamber i2 therebetween for the material to be processed, and treated internally and externally respectively by suitable temperature changing medium. Extending in this processing chamber i2 concentrio with the drums I0 and II is a hollow agitator or mutator shaft II, carrying on its outer side a pair of diametrically opposed sets of scrapers ll, which engage the inner surface of the outer drum ii, and on its inner side a pair of diametrically opposed sets of scrapers l5, substantially in quadrant relationship with said scrapers II, and

. engaging the outer surface of the inner drum I0.

The shaft I3 is provided with a series of ports so arranged with respect to the scrapers i4 and faces as said shaft is rotated. "'For that purpose,

Various other objects, features and advantages of the invention will be apparent from the following description, and from an inspection of the accompanying drawings, in which:

Fig. 1 is a transverse section through one form 66 the shaft it has a plurality of ports 2|), 2|, 22 and 23, arranged in longitudinal rows corresponding in number to the sets of scrapers, four of such rows A, B, C and D being shown equally spaced circumferentially of the shaft by longitudinal webs ll. Each longitudinal row comprises a plurality of ports, three being shown of rectangular elongated form arranged end to end and separated by circumferential webs I8 and I9. In order to prevent the material from quiescently collecting in the processing chamber I2 adjacent each comprises a port 22 similar to the ports 2|,

and two successive longer ports 23 similar to the ports 20. With this construction, the outer ends of the parts near the ends of the shaft I3 are in circumferential alignment, while the webs I3 between the ports of the two rows' A and B are staggered withfrespect to the webs I9 between the ports of the two rows C and D.

The outer scrapers I4 are shown mounted adjacent to the alternate port rows B and D inposition to direct the flow of the material scraped by said scrapers from the inner surface of theouter drum II radially inwardly through the ports of said rows and .towards the outer surface of the inner drum III. For so mounting the outer scrapers I4, the webs I! over the port rows B and D have threaded or otherwise secured thereto a series of screw pins 28 provided with heads 29, and the scrapers I4 have elongated slots 39 with enlarged sections to fit loosely, over said heads 29, and'reduced sections for snugly engaging said heads 29 upon endwise slide movement of the scrapers. The loose mounting of these scrapers I4 permits them to swing outwardly into engagement with the inner surface of the outer drum by the centrifugal action on said scrapers.

Each set of scrapers It comprises a plurality of blades arranged end to end with adjacent ends of successive blades extending almost to the center of the circumferential webs I8 or I9, and almost abutting as shown in Fig. 2, so that substantially the full length of the inner surface of the outer drum II is acted upon by these blades.

The inside scrapers I5-are supported adjacent to the alternate port rows A and C in position to direct the flow of material scraped by said scrapers from the outer surface of the inner drum I 9 radially outwardly through said ports of said rows and towards the inner surface of the outer drum II. For that purpose, the scrapers are supported on screw pins 33, threaded in alternate longitudinal webs I 1 of the shaft I3 between port rows A and D and between rows B and C, and

provided at their inner ends with flange heads 35. The scraper blades I5 have transversely elongated slots with portions large enough to pass over the flange heads and with portions smaller than said heads to retain said scrapers,

and are just slightly shorter than the corresponding ports adjacent to which they are mounted, so

that these blades can be easily mounted from.

drum II 'is directed by their camming action radially inwardly through the adjacent port and towards the outer surface of the inner drum I 9,

as shown in Fig. 1. As the next successive inner scraper blades I5 move along the region of the inner drum II) toward which the previously scraped material from the outerdrum II has been directed, they scrape that material and direct it radially outwardly by their camming action through the corresponding ports adjacent said blades and towards'said outer drum. In this manner, the material 'zig-zags in the annular chamber I! in and out of the ports and between the two refrigerated drums Ill and II, so that it is efficiently and uniformly acted upon by a temperature changing medium and effectively agis tated and worked. The material as it zig-zags circumferentially in the annular space I2 is simi" aneously moved by its pressure lengthwise of the apparatus to a suitable outlet as will be further described. During this flow lengthwise of the apparatus, the material is not short circuited along a path between the two refrigerated surfaces, but passes as described through the ports, which ofler the least resistance to the flow of said material. Certain features of the invention are also adaptable for uses in batch apparatus as well as in apparatus in which the material being treated is continuously passed through the chamber.

Although the inner blades I5 do not extend 1 across their corresponding circumferential webs the outside of the shaft I3 by slipp li uthem through said ports to the inside of said shaft, and then over the screw pins 33. Lateral movement of the blades I5 will then bring the reduced portions of the elongated slots thereon around the pins 33.

- In the operation of the device shown in Figs. 1

to 4, the material as itis scraped by the outer blades I4 from the inner periphery of the outer I8 and I9, the staggering of circumferentially alternate webs causes the inner blades of one longitudinal set to overlap the inner blades of the other longitudinal set. In this manner, although one set of inner blades I5 does not scrape the material at the region of the inner drum I0 opposite itsv corresponding webs I8 and I9, the other diametrically opposite set of inner blades l5 will pass over said region and scrape the material therefrom, so that the entire periphcry of "said inner drum is scraped during each revolution of the shaft I3.

In a similar manner, the overlapping 'of the outer blades ll of the two longitudinal sets prevents accumulation of unscraped material on th surface of the outer drum II opposite the por: tion of the webs I8 and I9 between the adjacent ends of said blades.

'I'hestaggering ofthe ports as described prevents collection of material between the circumferential webs I8 and I9 and the two drums III and II, since the area closed by one web is opened by a circumferentially succeeding alternate port.

Figs. 5 to 9 show the broad idea of the invention of Figs. 1 to 4 as applied to a commercial form of machine, in which the ported agitator shaft I3a is built to more effectively withstand the torsion stresses thereof to which it is subjetcedduring rotation thereof. In this construction, theagitator shaft I3a comprises two diametrically opposed inner circular arc sections II and I2, and two diametrically opposed outer circular arc sections "and 44, overlapping said =-inner sections at their sides as shown in Fig. '7,

and rigidly secured thereto by any suitable means as for instance welding at 45 to form a rigid tubular unit. The inner arc section 4| is provided with a series of rectangular notches 46 along one side thereof, three of these being shown separated by webs l1, and the other inner arc section 42 t is provided along one side with. a corresponding number of rectangular notches 4B,

staggered with respect to the notches 44 and. separated by webs 49. Similarly,.the outer are sections 43 and 44 are provided with rectangular notches 50 and respectively staggered with respect to each other, the notches 5| being sepa-- rated by webs 52 and the notches 5| by .webs 53.

The notches 4B, 48, 50 and II are dimensioned to form ports in the shaft Ila, corresponding and similar to the ports in the construction of Figs.

- ment with the inner surface of the outer drum II by the action of leaf springs 56, and are retained against circumferential displacement by pins 51 fixed to the webs 41 and 49 of the inner shaft sections 4| and 42, and extending loosely through holes in said blades I411.

The inner scraper blades l5a are. narrower than the scraper blades l4a, but are similarly retained in V-shaped seats 58 in the unnotched longitudinal edges of the inner shaft sections 4| and 42, and similarly urged against the outer surface of the inner drum III by leaf springs BI), and are retained against circumferential displacement by pins 6| fixed to the webs 52 and 53 and extending loosely into said blades.

The shaft I3a has secured at one end thereof as by welding a head plate 10,. provided with a plurality of outlets ll. A solid shaft 12 secured to this head plate ID as for instance by welding serves to transmit the drive power to the shaft Ila. At the other end, the shaft l3a is internally lined with suitable anti-friction metal 13 such as Babbitt metal for bearing purposes.

Fig. 9 shows the application of the ported agitator shaft of the present invention to a continuous freezer. In this construction, one end of the freezer is closed by a plate 15, having inlet openings 16 through which the material to be processed is delivered into the processing chamber II; This plate 15 also has an inlet opening 11 near its lower side for delivering a suitable refrigerant such as ammonia into the inner drum Ill, and an outlet I8 near the upper side of said plate for said refrigerant. In the interior of the refrigerated drum III is a hollow member 80 hav- 'ing a circular portion 8| to confine the passage of the refrigerant close to the peripheral wall of said drum, and having a channel 83 on its upper sid tapering downwardly towards the outlet 18 to facilitate gravitational flow of the liquid or condensed refrigerant towards said outlet 18.

The outer drum ii is jacketed with a cylinder, 85, which forms an annular space 86 with said drum for the refrigerant such as ammonia, and which is desirably covered with suitable heat insulating material 81. The space 86 has an inlet 88 near its middle, and two outlets 89 respectively adjacent its opposite ends for the refrigerant.

By means of this arrangement when the refrigerating apparatus is not operating in a. hooded condition, inlet 88 may have liquid refrigerant supplied thereto preferably at such a point as to cause the cold liquid refrigerant to fall first upon the uppermost side of the drum H and then to drain do'wnwardlyaround the sides of the drum. At the same time the liquid and gaseous refrigerant flows toward both ends of the apparatus toward the two outlets $9 in such to the fact that the contraction apathaswillchlllthedmm ll inauniform manner.

Heretofore, it has been found that in a refrigerating apparatus of this type wherein a revolving shaft with scrapers requiring a very small clearance is used, much less operating difllculties are encountered when the apparatus is disposed vertically than when disposed ho n'tally due a vertical cylinder in contact with cold refrigerant results in a' uniform distortion whereas a horizontal cylinder undergoes a non-uniform distortion.

By means of the central inlet for the refrigerant and the two outlets near the ends of the horizontal cylinder it is now found that much less distortion due to temperature differentials results and that a more satisfactory operation of the working parts of the structure is obtained. The ported agitator shaft Ha extending in the processing chamber II is journalled at one end on the inlet end of the inner drum Ill, and at the other end of the drive shaft 12 affixed to said agitator shaft is journalledin anti-friction bearings 9|, and is driven from a suitable source of power through a transmission including a pulley or gear-.92 on said drive shaft 12.

A receiving chamber 94 communicates with the outlet end of the processing chamber 12 through the outlet openings]! in the head plate, and has an outlet nozzle for discharge of the processed material.

In the operation of the apparatus, the material to be processed is delivered under pressure into the left hand end of the processing chamber I! (Fig. 9) through the inlets I6 and simultaneously at diametrically opposite sides of the ported shaft I311, and is discharged at theother end at diametrically opposite sides of said shaft. The material during its passage through the processing chamber 12 increases in viscosity, but the provision of the drive at the outlet end of said shaft effectively resists the greater torsion of the shaft at this end resulting from this increased viscosity 'of the material. The hollow shaft construction is advantageous in providing the strength necessary to keep the blades in alignclaim as new and desire to secure by Letters Patent is:- a

1'. An apparatus for processing fiowable material com-prising inner and outer drums defining therebetween an annular chamber for the material to be treated, a hollow shaft in said chamber encircling said inner drum, and having a pair of ports circumferentially spaced thereon, scrapers each having an edge abutting against the wall of said shaft within a corresponding one of said ports whereby the scraper may swing radially in respect to said wall and be readily removable therefrom, one of said scrapers being outside of said, shaft for scraping the material from the inner surface of the outer drum and directing it radially inwardly through the corresponding port toward the inner drum, and the other of said scrapers being inside of said shaft for'scraping the material froin the outer surface of the inner drum and directing; it ra-' dlally outwardly through the corresponding port toward the outer. drum.

2. An apparatus for processing flowable material comprising inner and outer drums defining therebetween an annular chamber for the material to be processed, a hollow shaft insaid chamber encircling said inner drum, having a plurality of ports throughsaid shaft, the ports being arranged in rows lengthwise of the shaft and said rows being circumferentially spaced thereon, and scrapers mounted on said shaft ad jacent to each of said rows for scraping the material from the opposed surfaces of said drums and directing it through the adjacent ports, each of said scrapers being relatively movable in respect to said shaft.

3. An apparatus for processingflowable material comprising inner and outer drums defining therebetween an, annular chamber for the material to be processed, a hollow shaft in said chamber encircling said inner drum, and having a plurality of ports circumferentially spaced thereon, and scrapers separate from and loosely mounted on said shaft adjacent to said ports for scraping the material from the opposed surfaces of said drums and directing it through the adjacent ports.

4. An apparatus for processing flowable mate, rial comprising inner and outer drums defining therebetween an annular chamber for the material to be processed, a hollow shaft in said chamber encircling said inner drum and having four rows of ports through the wall of said shaft. said ports being arranged in rows lengthwise of the shaft and said rows being circu'rnferentially spaced thereon, a pair of scrapers mounted substantially diametrically on said shaft adjacent to alternate rows of ports respectively for scraping the material from the inner surface of the outer drum, and directing it radially inwardly through said latter ports towards the inner drum, and a second pair of scrapers mounted substantially diametrically on said shaft adjacent to the other two rows of ports respectivel for scraping the material from the, outer surface of said inner drum, and directing it radially outwardly through said latter ports towards the outer drum, the ports of two adjacent rows being similarly spaced and positioned and the ports of the other two rows being offset axially in respect to 'the ports of the two first mentioned rows.

' 5. An apparatus for processing flowable material comprising inner and outer drums defining therebetween an annular chamberfor the material to be processed, a hollow shaft in said chamber encircling said inner drum, and having a plurality of circumferentially spaced rows of ports extending lengthwise of said shaft, the ports of one pair of adjacent rows being staggered with respect to the ports of the next successive pair of adjacent rows, means on said shaft adjacent to one row of ports of each pair for scraping the material from the inner surface of the outer drum, and directing it radially inwardly through the ports of said latter row towards the inner drum, and means mounted on said shaft adjacent to the other port row of each pair for scraping the material from the outer surface of said inner drum, and directing it radially outwardly through the ports of said latter row towards the outer drum.

.6. An apparatus for processing flowable material comprising inner and outer drums defining therebetween an annular chamber for the material to be processed. a hollow shaft in said chamber encircling said inner drum, and having four ,means carried on, relatively movable in respect circumferentially spaced rows of ports extending lengthwise of said shaft, the ports of two alternate rows being staggered with respect to the ports of the other two rows, said ports serving as passageways for the zig-zag movement of the material between the surfaces of said drums, and means for scraping the material from said surfaces as said shaft rotates.

, 7. An apparatus for processing flowable material comprising inner and outer drums definingtherebetween an annular chamber for the material to be processed, a hollow shaft in said chamber encircling said inner drum, and having four circumferentially spaced rows of ports extending lengthwise of said shaft, the ports of two alternate rows 'being staggered with respect to the ports of the other two rows, a pair of scrapers mounted substantially diametrically on said shaft adjacent to alternate port rows respectively for scraping the material from the inner surface of the outer drum, and directing it radially inwardly through the ports of said latter'rows towards the inner drum, 9, second pair of scrapers mounted substantially diametrically of said shaft adjacent to the other two port rows respectively 1 ber made of one piece and encircling said inner drum, said shaft having ports through which the material flows between the opposed surfaces of said drums as the shaft rotates, and scraper to, and readily removable from said shaft for scraping the material from said surfaces as said shaftrotates.

9. An apparatus for processing flowable material comprising inner and outer drums defining therebetween an annular chamber for the material to be processed", a hollow shaft in said chamber encircling said inner drum, and comprising a plurality of circular arc sections mounted in overlapping relationship and secured together to form a rigid tubular unit, said sections having recesses defining ports through which the material flows between the opposed surfaces of said drums as said shaft rotates, and rotatable scraper means for scraping the material from said surfaces.

10. An apparatus for processing flowable material comprising inner and outer drums defining therebetween an annular chamber for the mate- 'rialto be processed, a hollowshaft in said chamber encircling said inner drum, and comprising a plurality of circular arc sections mounted in overlapping relationship and secured together to form a rigid tubular unit, said sections having recesses defining ports through which the material fiows between the opposed surfaces of said drums as the shaft rotates, some of said sections having recesses along their longitudinal edges, and scraper blades seated in said last mentioned recesses for scraping the material from said surfaces as said shaft rotates.

11. An apparatus for continuously processing flowable material, comprising inner andouter cylindrical drums defining therebetween an annular chamber for material to be processed, means for continuous flow of material through the chamber, a rotatable hollow shaft in said chamber encircling said inner drum, said shaft having a plurality of ports therethrough arranged circumferentially around the shaft and providing for flow of material inwardly and outwardly between said drums as said shaft rotates, and means carried-by said shaft for scraping material from both of said surfaces as said shaft rotates.

.12. An apparatus for continuously processing flowable material, comprising inner and outer cylindrical drums defining therebetween an annular chamber for material to be processed, means providing for subjecting the outer surface of said outer drum and the inner surface of said inner drum to temperature changing medium, means including an inlet and an outlet for said chamber providing for continuous flow of material through the chamber, a rotatable hollow shaft in said chamber encircling said inner drum, said shaft having a plurality of ports therethrough arranged circumferentially around the shaft, and means carried by said shaft and operative upon rotation of the shaft for scraping material from the inner surface of said outer drum and from the outer surface of said inner drum and effecting zig-zag movement of the material inwardly and outwardly between said drums through said ports as the material flows longitudinally through said chamber.

t 13. An apparatus for processing fiowable material, comprising inner and outer cylindrical drums defining therebetween an annular chamber for material to be processed, a rotatable hollow shaft in said chamber encircling said inner drum, said shaft having a plurality of ports therethrough arranged circumferentially around the shaft, means carried by said shaft for scraping material from the inner surface of the outer drum and directing it inwardly through certain of said ports towards said inner drum, and ineans carried by said shaft for scraping material from the outer surface of said inner drum and directing it outwardly through other of said ports towards H said outer drum, said scraping means and ports beingarranged so as to cause zig-zag movement of material inwardly and outwardly between said drums and through said ports as said shaft is rotated. n

14. An apparatus for processing fiowable material, comprising inner and outer cylindrical drums defining therebetween an annularchamber for material to be processed, a rotatable hollow shaft in said chamber encircling said inner drum and having a plurality of ports therethrough, arranged in a plurality of rows extending longitudinally of the shaft and spaced circumferentially around the shaft, scrapers carried by said shaft adjacent certain of said rows of ports for scraping material from the inner surface of said outer drum and directing the material inwardly through the ports of said certain rows, and scrapers carried by said shaft adjacent other of said rows of ports for scraping material from the outer surface of said inner drum and directing the material outwardly through the ports of said other rows, said scrapers being located so as to effect zig-zag movement of material "inwardly and outwardly in thechamber between'said drums and through said ports as said shaft is rotated.

15. An apparatus for processing flowable material, comprising inner and outer cylindrical drums defining therebetween, an annular chamber for material to be processed, a hollow rotatable shaft in said chamber encircling said inner drum and having a plurality of ports therethrough, ar-

ranged in a plurality of rows extending longitudinally of the shaft and spaced circumferentially around the shaft, scrapers carried by said shaft adjacent to certain of said rows of ports for scrapingmaterial from the inner surface of said outer drum and directing the material inwardly' through the ports of said certain rows. and scrapers carried by said shaft adjacent other of said rows of ports for scraping material from the outer surface of said inner drum and directing the material outwardly through the ports of said other ows, said scrapers being located so as to effect zig-zag movement of material inwardly and outwardly between the walls of said drums through said ports as said shaft is rotated, and

the ports of some of said rows being staggered 17. A continuous freezer for flowable material comprising inner and outer refrigerated drums defining therebetween an annular chamber for the material to be refrigerated, an inlet at one end of said chamber and an outlet at the other end for the material to be refrigerated, a hollow shaft in said chamber encircling said inner drum, and having ports through which the material flows between the two refrigerated surfaces as the shaft rotates, a drive shaft secured to said hollow shaft at the outlet end of said chamber, and scraper means carried on said shaft for scraping the material from the refrigerated surfaces of said drums as said shaft rotates.

18. In a refrigerating apparatus, the combination comprising a cylindrical drum, a hollow member in said drum extending substantially the full length thereof, and having a channel along one side and a circular section along its remain ing side, the peripheral wall of said member being spaced-from the peripheral wall of said drum to form a; passageway, and said drum having a refrigerant inlet and outlet at one end for said passageway, said outlet being in alignment with one end of said channel.

19. In a refrigerating apparatus, the combination comprising a substantially horizontal cylinside, the peripheral wall of said member being spaced from the peripheral wall of said drum'to form a passageway, and said drum having a refrig erant inlet and outlet at one end for said passageway, said outlet being at the upper side of said drum in communication with one end of said channel, and said inlet being at thelower side of said drum, said channel having its crosssectional area progressively increased towards its,

outlet end.

20. An apparatus as recited in claim 19, characterized in that the longitudinal base of the channel inclines downwardly towards the outlet to provide for the gravitational flow of the refrigerant towards said outlet.

21, In a refrigerating apparatus, the combination including a horizontally disposed cylindrical casing, a path for refrigerant along the outer wall of said casing and including a refrigerant inlet disposed adjacent the middle thereof and refrigerant outlets disposed adjacent the two ends thereof, a second cylindrical casing disposed concentrically within said first casing and form ing an annular space therebetween through which material to be cooled may be passed, a refrigerant inlet and outlet connected to the interior of said second casing, and rotatable means located within said annular space.

BRUCE DE HAVEN MILLER. HENRY W. BEVARLY.

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