US1572419A

US1572419A - Centrifugal separator

Info

Publication number: US1572419A
Application number: US457652A
Authority: US
Inventors: Birchall William
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-04-01
Filing date: 1921-04-01
Publication date: 1926-02-09
Anticipated expiration: 1943-02-09

Description

1921 3 Sheets-Sheet 1 W BIRCHALL CENTRIFUGAL SEPARATOR Filed April 1,

Feb. 9 1926.

[A VENTOR ATTORNEY.

Feb. 9 1926.

W. BIRCHALL GENTRIFUGAL SEPARATOR Filed April 1, 1921 3 Sheets-Sheet 2 kW I Patented Feb. 9, 1926.

UNITED STATES WILLIAM BIRCI-IALL, OF ASHBOURNE, PENNSYLVANIA.

GENTRIFUGAL smmrmron.

Application filed April 1, 1921. Serial No. 457,652.

To all, whom it may concern Be it known that I. WILLIAM BIRCHALL, a citizen of the United States, and a resident of Ashbourne, in the county of Montgomery and State of Pennsylvania, have invented an Improvement in Centrifugal Separators, of which the following is a specification.

M invention relates to apparatus for separating liquids and solids from each other and also to improvements in the method of effecting such separation, and it has for its general object to effect a more eflioient and a more economical separation than has been possible by the use of apparatus and methods heretofore known and of which I am aware.

.A further object is to provide an apparatus which may be operated continuously, thus avoiding the necessity for interruptions and delays due to the deficiencies of apparatus as heretofore constructed.

It is also an object of my invention to provide an apparatus in which the parts are compactly related and arrangedso that it will occupy a relatively small space thereby economizing ground or floor space in the factory or plant where the apparatus may be in' use.

A further object of my invention is to provide means whereby the solid material which collects upon the inside surface of the outer wall structure of the apparatus may be continuously dislodged within a certain predetermined period after the same has first been deposited upon such surface.

Other objects and advantages of my invention will appear in the detailed description thereof which follows or will be apparent from such description.

In order that the principle of the invention may be more readily understood and its practical advantages from an economical standpoint more fully appreciated, reference may be had to the accompanying drawings in which I have illustrated certain me chanical embodiments of apparatus embodying the said invention. It will be understood, however, that various changes in the details of construction and in the arrangements of parts may be made within the scope of the claims appended hereto without departing from the said invention.

In the drawing:

Fig. 1 is a vertical longitudinal sectional view of an apparatus constructed in accordance with and embodying my invention, the said view being taken on the dash and dot line 1-1 of Fig. 2;

Fig. 2 is a transverse sectional view taken on the dash and dot line 22 of Fig. 1;

Fig. 3 is a view taken on the dash and dot line 3-3 of Fig. 1 showing a transverse sectional and a top plan view of the apparatus;

Fig. 4 is a vertical sectional View taken on the dash and dot line 4-4 of Figs. 2 and 3, the said view showing portions of the mechanism in elevation;

Fig. 5 is a transverse sectional view showing a slight modification of the structure; and

Fig. 6 is a transverse sectional view show ing still another modification of the construction.

Referring to the drawings, 1 designates the central hubportion of a spider having radially extending spokes or arms 2. The said hub is provided with an upward extension 3 provided with a drive pulley 1 intermediate its ends, and a gear 5 at its upper end. The spider arms 2 support at their outer ends a rim 8 having an upwardly extending flange 10 to which is secured the upper ends of curved plates 11 by means of bolts and nuts 12. There are four of these plates as shown in Fig. 2, and the opposite vertical edges of each terminate in inwardly extending flanges 13, best shown in Fig. 2 of the drawings. The upper ends of the said flanges abut the lower side of the rim 8. The "opposite lower ends of the curved plates 11 are secured to a downwardly extending annular flange 15 secured to a rim carried upon the outer ends of radial spokes 16 of a spider having a central hub 17. The lower ends of the curved plates 11 are secured to the annular flange 15 by means of nuts and bolts 18, and the lower ends of the inwardly extending flanges 13 abut aga'nst the upper side of the rim carried at the outer ends of the radial spokes 16.

Situated inwardly of the curved plates 11 are foraminous plates 20 and inwardly of the latter and in contact therewith and secured thereto are sheets of fabric 22, such as canvas. The foraminous or perforated plate 20 and the sheet of fabric 22 of each segment or section are clamped between

curved metal bands

24 and 26, the former being located upon the outside of the fou i T raminous sheet 20 and the latter upon the inside of the sheet of fabric 22. The said

bands

24 and 26 and the foraminous plate 20 .and fabric sheet 22 are secured together by means of screws 27 located at intervals.

In the construction as shown there are two sets or couples of these bands arranged between the opposite upper and lower ends of the foraminous sheet 20 and the canvas sheet 22. The upper and lower ends of the fabric sheets 22 of the segments or sections are secured to curved bars or parts 30, being clamped between the inner curved sides of the latter and the clamping strips 31 by means of screws 32. The lower side of the upper part 30 is inclined upwardly and outwardly while the upper side of the lower part 30 is inclined outwardly and downwardly. The said parts 30 are secured to the curved segmental plates 11 by means-of screw bolts '33, the latter extending through slightly elongated openings in said plates. The u per and lower ends of the foraminous p lates 20 are secured in any suitable manner, preferably by welding, to the parts 37, the curvature of which corresponds to the curvature .of the plates 11 and 20. The said parts 37 are secured in like manner to the plates 11 a short distance from the per and lower ends thereof, as shown. e opposite edges of the foraminous plates of the respective segments or sections are secured, preferabl by welding, to the inner edge portions of the inwardly extended flanges 13 upon the opposite vertical edges of the plates 11. The upper side of the upper part 37 is inclined inwardly and downwardly and is adapted to contact with the oppositely inclined under surface of the upper part 30 while the lower side of the lower part 37 is inclined inwardly and upwardly and is adapted to contact with the oppositely inclined upper surface of the lower part 30. ,The innersides of the clamping strips 31 of the respective segmental sections rest against the outer sides of the shoulders 40 upon the inner edge portions of the rims carried by the

spokes

2 and 16 of the spider structures. The opposite vertical edge portions of the fabric sheets are bent outwardly, as indicated at 41, aroundthe outer sides of the inwardly extending flanges 13 of the respective curved segmental lates 11 and are clamped be tween the anges of the adjacent opposing edges of such plates. The spaces between the outer plates 11 and the foraminous plates 20 are divided into relatively, narrow compartments or spaces by the vertically arranged narrow metal strips 45, the outer edges of which are connected to the inner sides of the plates 11 and the inner edges thereof to theouter sides of the plates 20, such connection to the two plates being elfected preferably by welding. The inner edges of said strips 45 are rovided with notches 46 in which the meta bands 24 are seated, the said bands and strips being con- I nected preferably by welding.

In assembling the parts of any one of the segments of the apparatus, the plates 11 and 20 and the metal strips 45 and band 24 are first secured together in the manner as above described, and thereafter the canvas sheet 22 is placed in position and is clamped and held against the foraminous sheet by the retaining bands 26. The upper and lower ends of the fabric sheet 22 may then be clamped between the clamping plates or strips 31 and the inner edges of the upper and lower parts 30 by means of the screws 32. The said parts 30 are then placed in position upon the outer sides of the parts 37 and are drawn outwardly and tightly against the upper and lower sides 0 the parts 37 b of the wed ging action diie to the inclined surfaces of the said

parts

30 and 37 the fabric is stretched longitudinally.

The metal strips 45, previousl referred to, form a foundation for the oraminous plates 20 and the fabric lining sheets 22 secured thereto. They insure a true radial surface and also insure the necessary spaced relation between the foraminous plates 20 and the outside plates 11 for receiving and collecting the liquid which passes through the fabric lining. These strips also reinforce the structure comprising the plates 11 and 20 and revent distortion thereof due to the centri ugal force developed when the apparatus is operated.

The cylindrical structure comprising the outer plates 11, the foraminous the porous sheets 22, etc., may be efined or regarded broadly as separating means; that is, the means for separating the solid and liquid content of a mixture of solids and liquids which has been deposited upon the inside surfaces of the porous sheets by the delivery means.

It will be observed that the s ider structures comprising the spokes 2 an the spokes 16 are connectedand bound together by means of the plates 11 in the manner as heretofore described, so that when power is applied to the wheel or pulley 4, rotation of both the said spider structures is effected together with the segmental structures comprising the outer plates 11, the inner spaced foraminous plates 20, the fabric sheets 22, and the other parts of the structure, heretofore referred to, associated with and binding together the parts particularly mentioned.

50 designates a central shaft which, except at its lower end, is hollow; The said shaft extends through openings in the hubs 1 and 17 and is supported atits lower end upon ball bearings 51 supported in a boxthe screw bolts 33. By reason lates 20,

like holder or support 52 which is in turn supported u on beams 53, of any suitable character, on y portions of which are shown in the drawings. A sleeve 54 of Babbitt or other suitable packing metal is situated within the holder 52 and surrounds a small portion of the shaft 50 adjacent its lower end. It may be noted that the lower end of the hub 17 rests=upon the upper edges of the box-like support 52 and of the sleeve .54 from which it is apparent that the structure comprising the parts secured to and carried at the upper and lower spider structures previously referred to, is supported upon. the said support 52.

1 In the structure as shown in Figs. 1 and 2. I have provided a plurality of arms 56 having distributing passageways extending therethrough for conveying the mixture of solids and water from the hollow shaft 50 to the outer cylindrical portion of the apparatus comprising the fabric sheets 22 and the parts to which they are attached. The

mixture of solids and water is'supplied to the hollow shaft 50 in any suitable manner as by means of a tank or reservoir, not shown, from which it is delivered by gravity, or it may be supplied by means of a force pump or other suitable means, not shown.

As shown in these figures of the drawings, there are three groups, 60, 61 and 62, of these arms arranged at angles of 120, apart. The arms of the respective groups are arranged one above the other. Upon reference to Fig. 1 of the drawings, it will be noted that each arm of each roup, 60, 61 and 62, comprises three sets 0 passageways 64, each of which is in registry or alinement I with openings 65 in the hollow shaft ing flanges 71 which are secured together to clamp the said head portions rigidly to the hollow shaft 50 by means of nuts and bolts 72, as best shown in Fig. 2 of the drawings.

By reference to Fig. 20f the drawings it will be observed that the outer end portions of the passageways or of the walls forming the passageways 64 are curved rearwardly; that is, in a direction the reverse .of that in which the. revolving parts of the apparatus are rotated as will be hereinafterdescribed. The forward walls of the said pas-' sageways terminate at a point adjacent the inner cylindrical surface formed by the fabric sheets 22, as indicated at in'Fig. 2; whereas the opposite rear walls of the said passageways are curved and extended rearwardly, as indicated at 81, the outer surfaces of said curved apron-like portions 81 being situated adjacent to but not in contact with the inner cylindrical surface formed by the said fabric sheets. The rear ends of these apron-like portions 8.1 terminate .in lines or planes, extending diagonally of the width thereof, as indicated at 83 in Fig. 1 of the drawings, and downwardly and forwardly, also as indicated. The purpose of terminating the rear ends of the said apronlike portions 81 along diagonal lines as indicated is to cause the solid material which is deposited upon the inner surfaces of the fabric sheets 22 to have a tendency to move upwardly as the said aprons travel thereover and in contact therewith.

The portion of the shaft 50 above the upper end of the extension 3 of the hub 1 is supported in a tubular bearing 85 constituting a portion of a structure which supports certain gear mechanism by means of which the said shaft is driven and which will now be described. The gear 5 is in engagement with a pinion 87 which in turn engages a gear 90 secured to the lower end of a. shaft 91 journaled in abearing 92. Upon the upper end of the said shaft a gear 93 is secured which is in engagement with an intermediate gear 94 which in turn engages a gear 95 which is secured by means of clamping bolts 96 to the shaft 50. The structure comprising the

bearings

85 and 92 is supported upon the I-beams 97, but the supports of the latter are not shown.

The relation of the gears just described is such that the shaft 50 and the distributing arms carried thereby and through which the passageways 64 extends rotate with greater speed than does the surrounding structure comprising the

parts

11, 20 and 22. Both of these parts of the structure; that is to say, the shaft 50 and the parts carried thereby, and the upper and lower spider structures and the parts carried thereby, rotate in the same direction, anticlockwise, as indicated by the arrow 99, in Fig. 2. By reason of the fact that the shaft 50 and the parts carried thereby rotate .at greater speed than the surrounding parts comprising the inclosing

cylindrical portions

11, 20 and 22, it is apparent that there will be relative movement between the apron-like portions 83 and the adjacent cylindrical canvas sheets or lining of the cylindrical surrounding structure. Thedi mensional relation of the gears may be varied so as to change the relative speed of movement of the arms 56 and the. outer cylindrical structure comprising the fabric sheets 22 and the plates 11 and 20.

The material, comprising a mixture of liquids and solids, having been thoroughly intermixed and being in a semi-liquid or a plastic condition, is delivered to the apparatus through the hollow shaft 50. The said shaft with the distributing arms 56 having the passageways 64 therethrough and the surrounding structure of the apparatus being rotated in the manner indicated, the mixture is caused by centrifugal action to flow outwardly through the passageways 65, into and through the passageways 64 and is delivered or discharged from the latter against the fabric sheets 22. The liquid content thereof escapes from the mixture through the porous fabric and sheets 22 and through suflicient period of time to permit a greater or less proportion of the water content of the mass to separate therefrom and flow outwardly through the fabric sheets 22 and the foraminous sheets 20. The solid content, by such partial separation of the water, is thereby rendered sufficiently stiff that it will not run or fall down the inside surfaces of the fabric sheets, thus permitting the removal of the remainder of the water content or at least all that it is possible toremcve by centrifugal force. The inside relatively narrow curved bands 26 and the lower strip or band 31 being respectively situated. at the lower edge of the arms containing the passageways of the respective groups employed in the construction as shown in Figs. 1 and 2, act as supports and aid in preventlng the material, when in relatively soft condition as when it first lodges'against the inside surfaces of the fabric sheets 22, from falling or sliding down the inside surfaces of said sheets.

Situated in front of and supported by each group of arms containing the distributmg passageways 64, I have provided means for removing the solid material, which has been deposited upon the inside surfaces of the fabric sheets by the first preceding arm of the series. The means provided for this purpose comprises a plurality of scrapers I each including a plurality of spirally arranged scraping blades 110 secured to a central core portion 111 which in turn is secured to a shaft 112 thelower end of which The is supported in a socket 115 formed in the upper side of a bracket 116 projecting forwardly from the lowermost of the arms of the respective groups of arms. The intermediate portion of the shaft 112 extends through and is supported by brackets 117 and 118 secured to the lower outer edge portions of the intermediate and topmost of the arms 56, while the upper end of the said shaft extends through and is supported by Fa bracket 120 projecting forwardly from the upper edge of the topmost of the said arms One of these scraping devices is associated with and supported by each groupof

arms

60, 61 and 62.

The upper end of the shaft 112 is provided with a pinion 125 which engages a spur gear 126 which is carried upon the under side of the spokes 2 of the uppermostof the two spiders heretofore referred to.

It has already been pointed out that the speed. of rotation or movement of the arms 56 carried by the shaft 50 is greater than that of the spokes 2 upon the outer end porions of which the spur gear 126 is carried. It follows, therefore, that the speed of revolution or movement of the pinions 125 is greater than that ofthe spur gear with which they are engaged, and that consequently the said pinions 125, inaddit-icn to their bodily movement around the axis of the shaft 50, are also independently rotated in an anti-clockwise direction about the r respective axes.

The outer edges of the spiral blades 110 are situated adjacent but not quite in contact with the inside surfaces of the fabric sheets 22 and as thev rotate they scrape off or remove the solid material which has' been deposited upon the inside surfaces of said sheets and from which the water has been removed by centrifugal force. Each scraper 'removes the material which has been deposited from the passageways through the arms immediately preceding and in front of the same. The material thus removed descends by gravity and falls between the spokes 16 and passes into the upper end of a receptacle .130, only a portion of which is shown. I

In Fig. 5 I have shown a construction similar to that shown in Figs. 1 and 2 with the exception that only one group of arms 56 is shown which group is designated 135. The apron-like portion 136 extending rearwardly from the outer end of the rear wall inside surfaces of the fabric sheets for a longer period than is necessary where such material is less soft. By holding the softer material in place for alonger period a. sufficient quantity of water is removed therefrom to render the same sufficiently stiff to hold its form or shape upon the inside surfaces of the fabric sheets as the latter rotate. The scraper structure indicated at 137 in this figure is the same as that shown in Figs. 1 to 4 inclusive.

In operating upon some material it may be found necessary to sustain the same against the inside surfaces of the fabric sheets for a. longer period even than would be possible with the construction as shown in Fig. 5. To meet such a situation or con dition, I have provided the construction indicated in Fig. 6 in which the part 140, which performs the function of the aprons S1 and 136, extends entirely around the structure forming a cylindrical member, the external surface of which is situated adjacent to but not in contact with the inside surfaces of the fabric sheets. The forward end portion 140 of the member 140 is integral with the rear wall of the arm or arms 141 having passageways 142 therethrough, only one of which is shown. The opposite end of the part 140 is connected by an inwardly curved portion 145 to the forward wall 146 of the arm or arms adjacent the outer end thereof. At its outer end or edge the said forward wall is provided with a. forwardly projecting portion 147 which acts as a scraper to remove the solid material which has collected upon the inside surfaces of the fabric sheets. I have also provided a spiral conveyer structure 148 which is situated within the cylindrical space formed within the forward projection 143 and the connecting portion 145. The said conveyer structure 148 is supported and rotated in the same manner as shown in Figs. 1 to 4 inclusive and its structure is similar to that of the scrapers in the preceding figures of the drawing, except that the blades are arranged to force the solid material removed from the inside surfaces of the canvas sheets downwardly.

In order to prevent the formation of a vacuum between the layer of material deposited upon the inside surfaces of the fabric sheets 22 and the outside cylindrical surface of the part 140,Ihave provided passageways 150 which extend vertically through the part 140, which openings or holes are connected by means of slots 151 to the outer surface of the said part 140. These slots are inclined rearwardly as shown. As the part 140 is rotatedf air enters the openings 150 and the slots? connecting the same with the outer peripheral surface of the part or parts 140 and thus the formation of a vacuum between the outer peripheral surface of the said part 140 and the layer of material upon the inside surfaces of the fabric sheets 11 is prevented.

In both forms of construction shown in Figs 5 and 6 the circular double lines 11 are. intended to represent the position of the fabric sheets referred to and which are full shown and illustrated in Figs. 1, 2 and 4 of the drawings. v

As already stated, my invention is designed for the purpose of separating the solids and liquids from each other. It may be that the material which it is desired to secure or separate is contained in the liquid content of the mixture, as in the case of nitrates, particularly sodium nitrate of the Chilean deposits; or it may be that the material which it is desiredto secure is contained in the solid component of the mixture, such, for instance, as copper, gold, silver or other metal. In the former case the liquid which has been separated from the solid component of the mixture is treated in known manner to effect precipitation of the nitrate therefrom. In the latter case the great advantage of having removed the water from the mixture is that in the subsequent heat treatments according to known methods much less fuel would be required to effect separation of the mineral component than if the water or moisture had not been removed.

' Having thus described my invention, what I claim and desire to secure by Letters Patcut is:

1. In a centrifugal separator for separating solids and liquids, the combination of one or more radially extending arms, the said arm or arms having radial passageways extending therethrough, means for supplying a semiliquid mixture of solids and water to the said passageway or passageways, means for causing revolution of the said arm or arms to thereby force the said mixture outwardly in said arm or arms, a cylindrical means inclosing the outer end portion or portions of said arm or arms, the said arm or arms terminating in adjacent rela- Y tion to the inside surface of said means, and the said arm or arms being provided with an outwardly extending apron or aprons for supporting the said mixture in a layer against the inside surface of the said separating means.

2.- In a centrifugal separator, the combination of a hollow shaft, radially extending arms secured to the said shaft, the said arms being located vertically one above the other and having delivery passageways extending therethrough said passageways being in communication with the interior of the said shaft, means for causing revolution of the said shaft and the arms secured thereto, centrifugal separating means concentric with the said, shaft and inclosing the outer ends liquid material is delivered from the said shaft, means situated adjacent the outer end or ends of the said arm or arms against which the mixture is thrownfrom the said arm or arms, and means'carried by the said arm or arms for holding the said mixture.

for predetermined periods against the inside surface of the said separating means.

4:. In a centrifugal separator, the combination of a hollow shaft, a radially extending arm supported thereby, said arm having one or more passageways extending therethrough and being in communication with the interior of the said hollow shaft, means for causing revolution of the said shaft and the arm carried thereby, a cylindrical separating means inclosing the said arm, the outer end of which arm is situated in adjacent relation to the inside surface of the said separating means, means for causing revolution of the said separating means in the samedirection as but at a less speed than the speed of revolution of the said arm, and means situated in front of and moving with the said arm for effecting removal of the solid material deposited upon the inside surface of the said separating means.

- :5. In a centrifugal separator, the combination of a hollow shaft, a plurality of groups of radially extending hollow arms secured to and supportedupon the said shaft, means for causing revolution of the said shaft and the saidarms, a cylindrical separating means inclosing the said arms, the outer ends of the latter being situated in adjacent relation to the former and-the rear walls of said arms being extended and arranged in parallel relation to said se arating means, and means for causing revo ution of the said separating means in the same direction as but at a less speed than that of the said arms.

\ 6. In acentrifugal separator, the combination of a hollow shaft, aplurality of groups of radially extending arms secured to and supported upon said shaft, said arms each havin one or more distributing passageways exten ing therethrough, the said passageways communicating with the interior of the said hollow shaft for receiving the mixture to be separated, means for causing revolution of the said shaft and of the arms carried thereby, a cylindrical separating means inclosing the said arms, the outer ends of said arms terminating in adjacent relation to the inside surface of the said means, the mixture being adapted to be delivered against the said separating means, means for causing revolution of the said separating means in the same direction as but at a less speed than that of the revolution "of the said arms, and

means carried by the said arms for r'emov-* arms, the outer end or ends of the said armor arms terminating in adjacent relation to the said cylindrical means, and the said arm or arms having a rearwardly extending apron or aprons in adjacent relation to the inside of the said separating means for. holding the mixture delivered from the said passageway or passageways against the inside of the said separating. means, means for causing revolution of the said cylindrical means in the same direction as but at less speed than that of the revolution of the said arm or arms, and means for removing from the inside of the said separating means the solid material deposited thereon.

. 8. In a centrifugal se arator, the combination of a radially exten ing arm or arms, the said arm or arms having a passageway or passageways extending longitudinally therethrough through which the mixture of solids and liquids is adapted to be distributed, means for causing revolution of the said arm or arms, a cylindrical separating means inclosing the outer end portion or portions of said arm or arms, the-outer ends of said arm or arms being situated in adjacent relation to the said separating means, means for revolubly supporting the said cylindrical separating means, rotatable means carried by the said arm or arms situated in adjacent rela tion to the inside surface of the said separating means for removing therefrom the solid material deposited thereon, and means for causing rotation of the said rotatable means.

9. In a centrifugal separator, the combination of one or more radially extending arms,

the said arm or arms having passageways extending longitudinally therethrough for the delivery of-the mixture to be separated,

a shaft for supporting the said arm or arms, means" for causing revolution of the said shaft and the said arm or' arms carried thereby, a cylindrical separating means situated adjacent to and inclosin'g the outer end or ends of said arm or arms, and the said arm or arms having a rearwardly extending apron or aprons situated in adjacent relation to the inside surface of the said separating means, means for supporting the said cylindrical separating means, means for causing revolution of the said supporting means and of the said separating means in the same direction but at a less speed than that of the revolution of the said arm, a vertically disposed shaft or shafts supported upon the said arm or arms adjacent the outer end or ends thereof, said shaft or shafts being provided with spiral scraper blades for removing from the inside surface of the said separating means the solid component of the mixture deposited thereon, and means intermediate the said last mentioned shaft or shafts and the means for supporting the said separating means for causingrotation of the said shaft or shafts about its or their axis or axes.

10. In a centrifugal separator, the combination of a plurality of groups of radially extending arms, each arm of each group being provided with a longitudinally extend ing passageway through which mixtures of solids and liquids are adapted to be delivered, a shaft upon which the said arms are supported, means for causing revolution of the said shaft and the said arms supported thereby, a cylindrical separating means inclosing the outer end portions of the said arms, the outer ends of the latterterminating in adjacent relation to the inside surface of the said separating means, and the material from the said passageways being adapted to be thrown against the said separating means, means for supporting the said cylindrical separating means, the said supporting means being providedv with a spur gear which is concentric .with the said shaft,i

means for causing revolution of the said support and the separating means'supported thereby in the same direction as but at a less speed than that of the revolution of the said arms, spiral scraping means supported near the outer ends of the said arms, the said scraping means being situated adjacent the inside surface of the said supporting means,

and gears having connection with the said scraping means and being in engagement with the said spur gear whereby rotation of the said spiral scrapers about their respective axesis effected to remove from the said separating means the solid component of the mixture deposited thereon. 11. In a. centrifugal separator for separating liquids and solids, the combination of one or more groups of radially extending arms, the said arms being provided with passageways extending longitudinally therethrough for the delivery of mixtures of solids and liquids, a hollow shaft to which the said arms are connected and upon which they are supported, the said mixtureto be separated being adapted to be delivered from the said shaft to the passageways through the said arms, means for causing revolutionof the said, shaft and the arms carried thereby, a cylindrical separating means inclosing the outer ends of the said arms which ends terminate in adjacent relation to the inside surface of the said separating means, means for supporting the said cylindrical separating means, said supporting means having a spur gear thereon concentric with the said hollow shaft, means for causing revolution of the said supporting means and the separating means carried thereby in the same direction as but at a slower speed than that of the revolution of the said arm, shafts secured to the said arms adjacent their outer ends, the said shafts being provided with scraper blades the outer edges of which are situated in adjacent relation to the inside surface of the said cylindrical separating means, pinions secured to the said scraper blades supporting shafts and being in engagement with the said spur gear whereby rotation of the said shafts together with the scraper blades carried thereby is effected about their respective axes to remove fromthe inside surface of the said separating means the solid com ponent of the mixture deposited thereon.

12. In a centrifugal separator, the combination of a distributing arm or arms having delivery passageways extending longitudinally therethrough, means for supplying a mixtureof solids and liquids to the said passageways and forcing the same therethrough, a cylindrical separating means inclosing the outer end portions of the said armor arms, the said mixture being adapted to be delivered against the inside surface of the said cylindrical separating means,-and the said separating means comprising a plurality of segmental sections each including an inner porous wall and an outer non-porous wall spaced therefrom to form a chamber within which the liquid component of the mixture is received and from which it is adapted to be discharged.

13. In a centrifugal separator, the combination of a hollow shaft, radially extending arms secured to and supported thereby, said arms having delivery passageways extending therethrough, said passageways being in communication with the interior of the said hollow shaft, revoluble spider structures' situated above and below the said arms, the said spider structures having central hub portions through which'the said hollow shaft extends, and the arms of said spider structures being provided with rim portions at their outer ends, a plurality of segmental sections of separating means detachably secured independently of each other to and supported upon the outer peripheral edges of the said rim portions, means for causing revolution of the said hollow shaft and of the arms supported an outer foraininous metal plate, an outside solid metal plate secured to and supported in spaced relation to the said foraminous sheet,'and strips secured to the said plates, the said strips extending longitudinally of the said plates and being situated in spaced relation to each other and operating to retain the said plates in spaced relation to each other, substantially as described.

15. A centrifugal separator, comprising a cylindrical separating means consisting of a plurality of segmental sections supported in edge to edge relation with respect to each other, each of the said sections comprising an inner porous wall and an outer solid nonporous wall, the said walls being situated in spaced relation to eachother to form chambers for the reception of the liquid component of the mixture which is adapted to be thrown against the inside surface of the said porous wall. 1

16. A centrifugal separator, comprising a revoluble cylindrical separating means, means for delivering a mixture of water and solids against the inside surface of the said separating means, and the said separating means comprising a plurality of. segmental sections supported in edge to edge relation with respect to each other, each of the said sections including an inner porous wall structure and an outer non-porous wall in.

spaced relation thereto, the spacing of the said walls forming chambers in which the liquid component of the mixture is received, and the outer walls of the said segmental sections being provided with openings adjacent their lower ends from which the said liquid is adapted to be discharged.

17. In a centrifugal separator, the combination of cylindrical separating means comprising a plurality of segmental sections arranged and supported edge to edge, means for delivering a mixture of solids and liquids against the inside surfaces of said sections, the said sections each comprising an inner porous wall and an outer non-porous wall, the said walls being separated a distance from each other, and vertically arranged metal strips arranged at intervals in the space between the said walls and secured at their opposite edges to the inner and outer walls to divide the said space into a plurality of chambers for receiving the liquid content of the said mixture.

18. In a centrifugal separator, the combination of cylindrical separating means comprising a plurality of segmental sections arranged and supported edge to edge, means for delivering a mixture of solids and liquids against the inside surfaces of said sections,

the said sections each comprising an inner porous wall and an outer non-porous wall, the said walls being separated a distance from each other, vertically arranged metal strips arranged at intervals in the space besurrounding the lower portions of the outer I walls of said segments for receiving the liquid from the said chambers.

19. In a centrifugal separator, the combination of a revoluble separating means, revoluble means extending from the upper to the lower endof said separating means for delivering a mixture of solids and liquids to the inside surface of the said revoluble separating means, and means for causing the said separating means to revolve at a less speed than the speed of revolution of the said delivering means. Y

20. In a centrifugal separator, the combination of cylindrical revoluble separating means, revoluble means for delivering a mixture of solid and liquid substances to the inside surface of said cylindrical means, the

said delivering means terminating in adjacent relation to the inside surface of said separating means and having portions extended in parallel relation to said separating means, and means for causing the said separating means to revolve in the same direction as but at a less speed than that of the revolution, of the said delivering means.

21. In a centrifugal separator, the combination of revoluble cylindrical separating means, revoluble means for delivering mixtures of solids and liquids to the 1ns1de surface of said separating means, the said de- I livering means being provided with a rearwardlyextending a. ron structure situated adjacent andin para lel relation .to the inside surface of said separating means, and means for causing revolution of the said separating means in the same direction as but at a less speed than that of the revolution of the said delivering means.

22. In a centrifugal separator, the .comb1- nation of cylindrical separating means, means terminating adjacent the inside surface of said separating means for delivering a mixture of solids and liquids thereto, means for causing revolution of said delivery means means for causing revolution of said separating means in the same direction as but at less speed than that of the revolution of the said delivery means, means extending rearwardly from the outer end portion of the said delivery means and in parallel relation to the inside surface of the said separating means for retaining the said mixture against the said surface, and means for preventing the creation of a vacuum int rmediate the said separating means and the adjacent opposing surface of the said retaining means.

23. In a centrifugal separator, the combination of revoluble cylindrical separating means, revoluble delivery means terminating adjacent the inside surface of said separating means for delivering the mixture of solids and liquids to the said separatingmeans and having a curved extension extending rearwardly from the point of delivery of the material therefrom for pressing the solid content of the said material against the said separating means, and means situated at intervals upon the inside of said cylindrical separating means for preventing the mixture delivered to the said separating means from sliding downwardly.

24. In a centrifugal separator, the combination of revoluble cylindrical separating means, revoluble radial arms terminating at their outer ends adjacent the inside of said separating means, the said arms having passageways extending longitudinally therethrough for the passage of mixtures of solids and liquids, and the outer ends of the said arms and the said passageways curving rearwardly so as to deliver thesaid mixture'in a tangential direction with respect to the inside cylindrical surface of said separating means, the inner walls of" said arms extending beyond the forward walls and beyond the termination of said passageways, and means for supplying the said mixture to the said passageways, substantially as described.

25. In a centrifugal separator, the combination of rotatable separating means, r0- tatable means for supplying material to be separated to the inside surface of the said separating means, and independently rotaton, which means is supported upon and carried by said arm and means for causing rotation of said rotatable means.

27. In a centrifugal separator, the com; bination of revoluble arms having distributing passageways extending longitudinally therethrough, means for delivering a mixture of solids and liquids to the said passageways and forcing the same therethrough, rotatable separating means surrounding the outer ends of the said arms, said separating means comprising a plurality of segmental sections, and means for independently and detachably supporting said sections in edge to edge relation with respect to'each other.

28(In a centrifugal separator,the combination of rotatable separating means, rotatable means for supplying material to be separated to the inside surface of the said separating means, means supported upon the second named rotatable means for removing from the surface of said separator material which may be deposited thereon, the axis of said means being in parallel relation to the adjacent surface of the said sep arating means, and means for effecting rotation thereof.

In testimony that I claim the foregoin as my invention, I hax e hereunto subscribed my name.

WILLIAM BIRCHALL.