US2138468A

US2138468A - Centrifugal separator

Info

Publication number: US2138468A
Application number: US69291A
Authority: US
Inventors: Arthur U Ayres
Original assignee: Sharples Specialty Co
Current assignee: Sharples Specialty Co
Priority date: 1936-03-17
Filing date: 1936-03-17
Publication date: 1938-11-29
Anticipated expiration: 1955-11-29

Description

' Nov. 29, 1938.

A. u. AYRES GENTRIFUGAL SEPARATOR Filed March 17, 1956 Kii mu mmllllm IIIIIHIIIHH" I H l 2 Sheets-Sheet 1 INVENTOR. ARTHURU.AYRES BY Q ATTORNEY.

Nov. 29, 1938. A, U, AYRES' v 2,138,468

CENTRIFUGAL SEPARATOR Filed March 17, 1936 2 Sheets-Sheet 2 INVENTOR.

ARTHURU.AYIZES 1 16.5 BY W a, W

ATTORNEY.

Patented Nov. 29, 1%38 nnirnn stares anger Parent tripe CENTRHFUGAL SEIPAKEA'EQE Application War-ch 17, 1936, Serial No. 69,291

6 (Claims.

The present invention pertains to the type of centrifugal separator adapted to discharge continuously two liquid efiluents. Examples of separating operations which may be accomplished by the use of the centrifugal separator oi the invention are the concentration of emulsions such as cream and latex, the separation of immiscible liquids from each other, or the simultaneous separation of solid impurities from a 9 mixture of liquids or an emulsion while effecting separating or concentrating operations upon such liquids or emulsion.

One object of the invention has been to provide a centrifugal separator capable of concen- 3 trating emulsions without substantial coagulation of the dispersed phase of such emulsions.

In the concentration of latex, for example, it is important that the concentrating operation be carried on in such a manner as to avoid the coag- D ulation of latex particles and an object of the invention has been to provide a centrifugal separator which avoids agitation of the latex in such a manner as to efiect undesired coagulation.

A second object of the invention has been to provide improved flushing means by which the interior of a centrifugal rotor may be conveniently flushed out at desired intervals in such a manner as to effect a thorough cleaning thereof and displacement and recovery of concentrated 3; material.

A still further object of the invention has been to provide a centrifugal separator of improved design adapted to efiect simultaneous concentration of an emulsion or searation of immis- 5 cible liquids and removal of solid impurities from the desired effluents.

Other objects and the manner in which they have been attained will be evident upon a reading of the sub-joined specification in the light of the attached drawings, in which:

Figure 1 is a central longitudinal section of the centrifugal rotor of the invention illustrating certain of the parts in sideelevation,

Fig. 2 is an enlarged central longitudinal section through the lower part of the rotor illustrated in Fig. l,

Fig. 3 is an enlarged central longitudinal section through the top portion of the rotor of Fig. 1, the accelerator member being omitted from i this figure for the purpose of clarity of illustration,

Fig. 4 is a central transverse section taken on the line 4-4 of Fig. 2,

Fig. 5 is a transverse section taken on the line 5-5 of Fig. 2,

(GE. Eg -=27) Fig. 6 is a detailed perspective view illustrating the construction of a spacer member located in the upper end of the centrifugal rotor of the invention. The accelerator member which is located within this spacer member during the operation of the machine is omitted from this view,

Fig. 7 is a detailed cross-section taken on the line ll of Fig. 2, and

Fig. 8 is a central transverse section taken on the line t-& of Fig. l. w

In the particular form of the invention illustrated in the drawings, the centrifugal rotor i8 is provided with an inlet feed boss H which is surrounded by a conventional drag mechanism H2. The drag mechanism is secured in position on a base it which also carries a feed nozzle it through which the material to be treated is passed to the centrifugal-rotor. An auxiliary feed nozzle i5 is also secured to the base it and surrounds the feed nozzle i 1. The feed nozzle 29 M is provided, at a point above the upper end of the nozzle it, with a head it which is adapted to be impinged by liquid fed through the nozzle i5 and to deflect that liquid against the inner circumference of the boss it.

The lower end ll. of the rotor is provided with an annular flange it extending longitudinally interiorly of the rotor. I The upper end of the flange 08 forms a seat for a flange 2d of a feed liquid directing member it having a conical base portion. The flange it is cut away at spaced points, as illustrated at 2B, in orderto afford egress from the space between the member i9 and the bottom' portion of the bowl for liquid passing upwardly through that space.

A cylinder 22 is provided with a lower flange 23 adapted to be seated upon the flange it, This cylinder is held in position centrally within the rotor by means of a plurality of U-shaped spacer members 2a which occupy the space between the cylinder and the walls of the rotor. A transverse partition or cover 25 is secured in place at the upper end of the cylinder and provided with a depending flange 26 which surrounds the cylinder at its upper end. A plurality of spaced openings 27 are formed in this cover and a conical spreader member it is formed at the center of the cover. It is to be noted that the cylinder 22 is relatively short and that the main body of the centrifu al separator lies above that cylinder.

The feed liquid directing member I9 is provided on the upper side of its conical surface with a plurality of radially extending blades or fins 28 and on the lower side of its conical surface with a plurality of radially extending blades or fins 3E9. The i'ins 28 extend radially inwardly toward the zone of the feed opening 29 in the lowermost part of the member 119 and are of relatively narrow width. The spaced fins til extend radially from the outer surface of the member is to the inner surface of the lower end it of the rotor and thus serve rapidly to bring liquiclentering this space up to the rotational speed of the rotor. The main body of the centrii'ugal separator is provided with an auxiliary structure consisting of a plurality of radially outwardly extending curved stratifying plates til which are secured together by means of centrally disposed rings 32. The auxiliary structure consisting of these curved plates and rings is held in a position spaced from the walls of the rotor by means of a novel spacer member consist ing of U-shaped longitudinal members 36 secured to circular transverse members 35. The U-shaped members 34 occupy the space between the circular members 35 and the wall of the rotor and serve to hold the entire spacer structure centered within the rotor. The innermost portions or bases of the lJ-shaped members are provided with longitudinally extending openings as illustrated in Figures 1, 3 and 6 of the drawings to afford provision for deposition of solids through said openings. The accelerator structure is held in position within the rotor by means of this spacer member. The spacer member is held longitudinally in position in the rotor by means of the depending flange 36 of the inside dam disc 3.! of the rotor, the lower ends of the members 34 being supported upon the cover 25. The lighter efliuent is discharge from the rotor through outlets $38 and theheavier efiluent through outlets 39 controlled by a conventional ring dam 40.

In the use of the centrifugal separator in the concentration of a latex emulsion, for example, the latex emulsion is fed through the nozzle M into contact with the conical spreader member 4i and flows down the walls of the cylinder 22. Latex which reaches the lower end of the preliminary feed section of the rotor formed by the cylinder 22 and directing member 89 comes into contact with the blades or fins 28 formed upon the inner portion of the base of the member 19 and is thus accelerated to the rotational speed of the rotor. This feature of construction prevents flow of the liquid inwardly through the feed opening 29, since liquid having the rotational velocity of the rotor is naturally held outwardly under the influence of centrifugal force and cannot therefore escape through. the opening 29. As the operation of the machine is continued, the wall of liquid within the cylinder 22 will form inwardly to the point at which it overflows through the openings 21 at its upper end. When this stage of operation is reached, a rotating liquid wall of substantial depth will have been formed within the feed cylinder 22. Liquid deflected by the spreader member 4| will be impelled into contact with this wall and gradually accelerated up to the speed of the wall by such contact; Only a small part of the liquid Within the preliminary feed section -of the rotor is positively accelerated to the speed of the rotor by the fins 28, the remainder of the liquid being accelerated by the liquid wall against which it impinges after delivery to the rotor and deflection by the spreader member 4|.

These features of operation have important advantages in connection with the treatment of a material, such for example, as late):. Thus, the

essence turbulence exists in this preliminary feed section to prevent concentration of latex in this section but this turbulence is insufiicient to cause coagulation. The partially clarified latex fed to the rotor is thus passed upwardly through the I openings 2? into the zone of the rotor occupied by the accelerator stratifying plates. The concentration of the latex occurs in this zone. It is to be noted that latex fed to this accelerator zone has already attained substantial rotational j velocity incident to its passage through the feed section. Latex passing through the openings 2'! does not therefore undergo a sudden acceleration upon reaching the longitudinal zone of the rotor occupied by the stratifying plates. This factor is of importance in avoiding coagulation of latex particles.

Latex passing through the main body of the rotor above the openings ill is subjected to a simultaneous concentrating and clarifying operation. The provision of the'spacer member 33 which avoids contact oi the stratifying plates 30 with the wall of the rotor is important in connection with the clarifying aspect of this operation, for the fact that the accelerator plates are spaced from the wall of the rotor afiords a substantial free space between the ac- The concentrated latex is. contiuuously discharged through the lighter efiiuent discharge outlets 38 while the dilute phase is discharged through the outlets 39 and over thering dam 40.

When it is desired to clean the accelerator structure to remove deposited solids, the feed of material to the rotor is discontinued and. a washing liquid, e. g., water, is passed through the annular space afforded between the feed nozzle i5 and the nozzle it. This washing liquid impinges against the head 66 formed upon the nozzle M and is deflected into contact with the inner wall of the boss ll of the rotor. The centrifugal force generated by the rotation of the rotor causes the washing liquid to cling to this surface and be projected upwardly into the space occupied by the radially extending blades 30. These blades bring the washing liquid up to the speed of the rotor and this liquid is impelled outwardly through the openings 2| between the flange 20 and the flange I8 under the influence of centrifugal force. Washing liquid impelled through the openings 2| flows upwardly through the space between the cylinder 22 and the wall of the rotor under the influence of centrifugal force and does not come into contact with the separating zone of the rotor until it passes the longitudinal zone of the rotor occupied by the cylinder 22. The feed of washing liquid is maintained at a rapid rate and this washing liquid passes inwardly through the spaces between the stratifying plates and is discharged from the rotor through the discharge outlet 39,. displacing concentrated material toward the center and through outlets 38.

It will be seen that the centrifugal separator of the invention affords provision for a rapid 7 7 comprising a centrifugal rotor divided by a transverse partition into a preliminary feed section comprising an inner chamber and'a subsidence section into which material is adapted to fiow from said feed section, said partition being provided with openings through which material may pass from said chamber to said subsidence section, an annular longitudinal wall secured to said transverse partition and extending toward the zone of feed of material to the rotor, said wall'being annularly spaced from the inner circumference of the main body of the centrifugal rotor and forming with said partition said inner chamber adapted to receive liquid before said liquid is passed into the main body of the centrifugal rotor, means for feeding a liquid material to be subjected to a centrifugal separating operation into said chamber, and means for feeding an auxiliary liquid into the space between said annular wall and the wall of the rotor, whereby to feed said auxiliary liquid around said chamber and into the main body of the rotor without passing said auxiliary liquid through said feed section. 7

2.1m a centrifugal separator, the combination comprising a centrifugal rotor divided by a transverse partition into a preliminary feed section comprising an inner chamber and a subsidence section into which material is adapted to flow from said feed section, said partition being provided with openings through which material may pass from said chamber to said subsidence section, an annular longitudinal wall secured to said transverse partition and extending toward the zone of feed ofmaterial to the rotor, said wall being annularly spaced from the inner circumference of the main body of the centrifugal rotor and forming with said partition said inner. chamber adapted to receive liquid before said liquid is passed into the main body of the centrif- 'uga1 rotor, means for feeding a liquid material to be subjected to a centrifugal separating operation into said chamber, and means for feeding an auidliary liquid intothe space between said annular wall and the wall of'the rotor and radially extending accelerator members occupying the space between the main body of the rotor and said chamber, whereby to accelerate auxiliary liquid fed into said space to the speed of the rotor.

3. In a centrifugal separator, the combination comprising a centrifugal rotor having separate discharge outlets for separated liquid efiluents, means for feeding a liquid material to be subjected to a centrifugal separating operation to said rotor, a preliminary feed section within said rotor into which said material is adapted to be injected by said feeding means, means for maintaining a peripheral wall of material in said preliminary feed section during rotation of said rotor, said preliminary feed section being adapted gradually to accelerate the material fed thereto without substantial stratification thereof, means longitudinally beyond said preliminary feed section and spaced from said rotor for facilitating stratification of material fed to the rotor, and a circumferential wall around said feed section extending longitudinally of the rotor and spaced from the wall of the rotor for introducing-said flushing liquid directly into the outer radial zone of the rotor at a point surrounding said stratifying means.-

4. In a centrifugal separator, the combination comprising a centrifugal rotor having separate discharge outlets for separated liquid efiiuents, means for feeding a. liquid material to be sub- -jected to a centrifugal separating operation to said rotor, a preliminary feed "section within said rotor into which said material is adapted to be injected by said feed means, means at the upper end of said preliminary feed section for maintaining a peripheral wall of material in said preliminary feed section during rotation of said rotor, said preliminary feed section being adapted gradually to accelerate the material fed thereto without substantial stratification thereof, a. stratifying insert longitudinally beyond said preliminary feed section, and means for guiding a flushing liquid around said feed section without contact with the material in said feed section for introducing said flushing liquid directly into the outer radial zone of the rotor at a point surrounding said stratifying insert.

' 5. In a centrifugal separator, the combination comprising a centrifugal rotor, means for feeding a liquid material to be subjected to a centrifugal separating operation to said rotor, a preliminary feed section within said rotor into which said material is adapted to be injected by said feed means, means at the upper end of said preliminary feed section for maintaining a pcripheral wall of material in said preliminary feed section during rotation of said rotor, said preliminary feed section being adapted gradually to accelerate the material fed thereto without substantial stratification thereof, a stratifying insert longitudinally beyond said preliminary feed section, and means for guiding a flushing liquid around said feed section without contact with the material in said feed section for introducing said flushing liquid directly into the .outer radial zone of the rotor at a point surrounding said stratifying insert.

6. In a centrifugal separator, the combination comprising a centrifugal rotor having therein a. preliminary feed section having a plain peripheral wall throughout the major portion of its length and a subsidence section into which material is'adapted to flow from said feed section, means at the upper end of said preliminary feed section for maintaining therein a wall of material during rotation of said rotor, a passage in the base of said preliminary feed section, means for injecting a liquid material to be subjected to a coming in contact with said fins is accelerated.

ARTHUR U. AYRES.