US2200202A - Centrifugal machine for the separation of solid and liquid materials - Google Patents

Description

y ,1 0- c. E. HARVEY 2.200.202

CENTRIFUGAL MACHINE FOR THE SEPARATION OF SOLID AND LIQUID MATERIAL Filed July 17, 1937 4 Sheets-Sheet l 411T ff @T Z1 k 4 F 50 5/ 50 J2 J5 5% i I A5 l l 2L. If}! as 6- H I /0 27 ll' 4 25 I' 75 0 f i0 ll K I 22 F" 5, '4 Flfia I q 1 C. E. HARVEY May 7, 1940.

CENTRIFUGAL MACHINE FOR THE SEPARATION 0F SOLID AND LIQUID MATERIAL Filed July 17, 1937 4 Sheets-*Sheet 2 y 7, 1940. I c. E. HARVEY 2,200,202

CENTRIFUGAL MACHINE FOR THE SEPARATION OF SOLID AND LIQUID MATERIAL Filed July 17, 1937 4 Sheets-Sheet 3 iL-27 N y 7, 1940. c. E. HARVEY 2.200.202

CENTRIFUGAL MACHINE FOR THE SEPARATION OF SOLID AND LIQUID MATERIAL Filed July 17, 1937 4 Sheets-Sheet 4 Patented May 7, 1940 RATION OF SOLID AND RIALS LIQUID MATE- Cecil Ernest Harvey, Hornchurch, England Application July 1'7, 1937, Serial No. 154,302 In Great Britain July 25, 1936 4 Claims.

This invention concerns improvements in and relating to centrifugal machines for separating solid and liquid materials fromeach other. It is a particular object of the invention to provide a centrifugal machine which is especially adapted for the continuous separation of solids such as coal-dust, crushed grain and the like from liquids such as water, or for the treatment of materials such as sewage, and which will effectively replace known apparatus comprising settling ponds, slurry towers, dewatering sieves and so forth.

I According to the invention, a centrifugal machine for separating solid and liquid materials from each other-comprises a vertically disposed rotor with a conical wall which increases in diameter in the downward direction, discharge means for heavier solid material disposed around the periphery of the rotor at the largest'diameter thereof, means for feeding the solid and liquid materials into the upper end of the rotor, a lip extending inwardly from the wall of the rotor beneath said discharge means to provide a central opening for the discharge of liquid in a downward direction, valve-means controlling the discharge means, and means for actuating said valve-means during the operation of the rotor.

For example, the valve means may comprise a plurality of rotary star valves driven continuously from the rotating rotor of the machine.

The valve-means may be connected with the interior of the rotor by ducts extending tangentially of the periphery thereof.

'In conjunction with the valve-means, there may also be provided means for permitting the separate expulsion or escape from the solid material about to' be discharged of further liquid separated therefrom.

The invention will be clearly understood from the following description, given by wayof example, of machines constructed in accordance therewith. reference being had to the accompanying drawings, in which:

Fig. 1 is a vertical section of a complete appa ratus, the valve casings being shown in elevation, i

Fig. 2 is a section taken on the line A-B of Fig. 1,

Fig. 3 is a section taken on the line C-D of Fig. 1,

Fig. 4 is a detail view showing a valve casing and associated parts in vertical section with the valve in elevation,

Fig. 5 is a detail elevational view of the valvecasing taken from the right of Fig, 4 with the (o1. eas -20 deflecting means for the liquid escaping from the casing removed,

Fig. 6 is a section taken on the line E-F of Fig. 4, and

Fig. 7 is a fragmentary view, mainly in vertical. section, of the rotor of an apparatus according. to the invention, illustrating a modification.

Referring firstly to Fig. 1, the apparatus comprises an outer housing l with upper and lower transverse frame-members Zand 3. Upon the lower frame-member 3 is secured a plate 4 carrying a central thrust bearing 5 in which is rotatably mounted the lower end of a vertical shaft 6, the upper end of which passes through a journal bearing 7 carried on the upper frame-member 2 to receive a drive from any suitable means, illustrated as comprising a pulley 8 and belt 9. Al-

\ ternatively the shaft 6 may be directly coupled to an electric motor mounted on the cover la of the outer housing I.

The rotor II; is of truncated conical shape and is mounted on the shaft 6 by means of upper and lower spiders H and i2. The upper spider II is secured to the'shaft 6 through the intermediary of a deflector member l3 having a conical deflector plate 13a at its upper end located just beneath the inlet to the rotor. The lower spider It supports the rotor through the intermediary of the bottom plate hi thereof, a central liqu1ddischarge opening Ma. being formed in the plate It around the shaft 6.

A fixed vertical charging duct I5 is provided coaxially with the shaft 6 to extend just within the open upper end of therotor NJ. The raw material, for instance the wash discharged from the stills of a whisky distillery, is introduced into the rotor through a funnel l6 and a sloping pipe ll which opens into the duct [5.

Extending tangentially from the portionof the rotor of largest diameter, in the example shown the lowest part, are four wide, slightly flaring, ducts I8 (see also Fig. 3) which are closed at the outer ends by rotary star-valves l9 working in valve-casings 2 (see Figs. 4 to 6). Each valve l9 has four pockets which successively pass slowly through the four following positions: (1) a position in which the pocket is open to receive solid material from the corresponding duct I 8; 2) a position in which the pocket, filled with. solid material, is closed by the wall of the valve-' housing 29. This wall is advantageously perforated or slotted, for example, as illustrated in Figs. 4, 5 and 6 where 2! indicates circumferentially extending outwardly flared slots, so as to allow of the separate expulsion by, the effect of the centrifugal force of liquid still being carried along with the solid material. This latter, however, is retained. An upwardly inclined spoutlike deflector 22 outside the valve-housing directs the expelled liquid into an annular trough 23 extending around the inside of the housing I and draining to an outlet 24 (see Fig. 1); (3) a position in which the pocket is open to discharge the solid material, through an aperture 25 in the valve-housing 20, against the inner surface of the inner wall of the trough 23 from which it drops to a hopper-shaped outlet 26 from the housing l; (4) a position in which the empty pocket is closed by a blank wall of the valvehousing 20. To avoid danger of jamming of solid particles between the vanes of the valve l9 and the housing 20, the vane-edges may be designed to cut or crush particles encountered and/or may be made slightly helical as indicated in Figs. 4 and 6. The discharge opening 25 is similarly shaped, as clearly shown in Fig. 5.

'As will be appreciated, the discharge-ducts i8 and valve-housings 2H, spaced equally around the rotor Ill, are carried round with the latter as it rotates at high speed. The valves l9 themselves are rotated continuously in their housings 579 through vertical spindles 2! driven by gearing which is mounted, for example, above a plate 23 supported by a cylindrical wall 29 from the upper part of the rotor It. The drive is obtained by the rolling of pinions fill, mounted on the plate 28, around a gear ring 3! fixed to the central charging duct l5. These pinions 36 are connected to the valve spindles 2'! by horizontal shafts 32 and worm and worm-wheel gearing 33 which provides a high degree of speed-reduction, for example; a ratio of D to 1.

In order to avoid the formation of stagnant pockets of solid material within the rotor it! between the outlet ducts l8, false vertical walls 34 are provided to extend from the bottom M to the sloping wall of the rotor (see Figs. 1 and 3) and provide between them tapering or hopperlike mouths to the said ducts it. A depending skirt or lip 35 is provided around the opening Ma in the bottom of the rotor ill to guide the liquid discharged from the latter into a collecting chamber 36 carried on the plate t in which is secured a discharge pipe 3? for conducting the liquid to the exterior of the housing 8.

The operation of the machine is as follows:

The rotor ill is set in rotation at a high speed in the direction of the arrow A in Fig. 2 and the raw material is fed in through the funnel l5,

' pipe l1 and duct E5. The material falling from the duct is thrown by the deflector plate 530. towards the drum-wall of the rotor It]. At this stage. separation of the solid and liquid components commences in known manner and continues as the material passes downwardly in the rotor. 'The separated solid material collects on the inside of the drum-wall of the rotor, the layer of solid material being thickest at the bottom on account of the conical shape of the rotor, and the separated liquid collects on the inside of the solid material. The layer of liquid builds up so that its inner periphery occupies the position indicated by the lines 38 in Fig. 1 and then continuously spills over the edge of the opening Me in the bottom M of the rotor to be guided by the skirt 35 into the collecting chamber 36.

The solid material fills the hopper-like mouths to the ducts I8 and also the latter and is continuously removed by the action of the valves l9, as already described. The liquid expelled from the solid material through the slots 2!, during the passage of the solid material through the valve-housings 2f], is deflected by the elements-22 into the trough 23. This liquid may in some cases be returned to the funnel it as it may contain some fine particles of solid material in suspen- SlOn.

Should it be desired to separate Jvery fine solid particles from a liquid, however, it is advantageous to make use of the means illustrated in Fig.7, the action of which is to permit of a higher mean peripheral speed being imparted to the material as it travels through the rotor id.

Such means comprises one or more discs 39 (two are shown) secured on the shaft 6. These discs are disposed transversely within the rotor and increase in size in the downward direction, the lower (or lowermost) disc being of approximately the same diameter as the discharge opening Ma in the bottom of the rotor. This discharge opening is, however, larger than could be the case with the arrangement shown in Fig. l owing to the discs 39 causing the inner surface Ml of the liquid layer to assume a stepped formation.

An alternative to the use of such discs 39 is to rotate the rotor it at a higher speed but it is usually found that the speed of rotation of the valves 19 then becomes too high and necessitates an alteration in the speed-reduction gear. It is preferred therefore to provide a variable-speed gear, 'for example between the gear ring 35 and the duct 95 whereby the speed of rotation of the valves 59 may be varied relatively to the speed of rotation of the rotor 10. A suitable type of vari-' able-speed gear for this purpose is an'epicyclic gear.

When conditions require it, a'further percentage of liquid may be removed from the solid material discharged from the valve-housings by providing a slowly rotating circular table of perforated or foraminous material, e. g. wiregauze,

at such a location that it receives the solid material dropping from the inner wall of the trough 23. A fixed scraper or knife is provided to cooperate with the upper surface of the table and gradually feed the solid material outwardly across the same to discharge over the edge thereof on to a suitable conveyor. The liquid meanwhile drains through the table to be collected in a stationary tray or trough.

For some purposes, the machine may be modified to efiect a selectiveseparation of solid materials. In the separation of coal-dust, for example, the larger particles of coal are found to separate almost upon entering the rotor and tend to collect higher up its side. To take advantage of this effect, a ledge may be provided at an intermediate level in the rotor and the space above the said ledge may be provided with a separate set of discharge-ducts and valves. arrangement, it will be possible to separate solid material into two or even more components accoal from pyrites, shale or clay.

Although the ducts H? are each shown in Figs. 1 to 3 as extending in a direction opposite to that in which the rotor i0 is driven, these, ducts may if desired extend in the direction of rotation of the rotor. v

In some cases, especially where machines of large capacity are'concerned, the plate 28 may be constructed of a relatively smaller diameter and the drive from the worm and worm-wheel gearings 33 to the valves l9 would then comprise universally jointed shafts disposed overthe With this greater part of their length substantially parallel with the drum-wall of the rotor l0.

What I claim is:

l. A centrifugal machine for separating solid and liquid materials from each other, comprising a vertically disposed downwardly flaring conical drum-rotor, discharge ducts for separated solid material vextending tangentially outwardly from the periphery of the rotor at its maximum diameter, discharge valve means at the outer ends of the-said ducts, driving means operative for driving the said valve-means during operation of the machine, means for feeding the materials to be separated into the upper end of the rotor,

and a central opening in the bottom of the rotor for the discharge of separated liquid material.

2. A centrifugal machine according to claim 1, wherein the discharge ducts for the solid'material flare slightly towards the valve means.

3. A centrifugal machine for separating solid and liquid materials from each other, comprising a flaring vertically disposed rotor-drum, valveliquid material from the said drum, the valve housings being each formed with an outwardly aperturedwall-portion over which the solid material is traversed by the respective valve to permit of expulsion, under centrifugal force, of liquid still being carried along by the solid material.

4. A centrifugal machine according to claim 3, comprising also a wall positioned for the discharge against it of solid material discharged from the valve-housings, an outlet towhich the said material falls from the said wall, a deflector positioned for receiving liquid expelled by Way of the apertured wall-portions of the said housings, and a collecting trough positioned for receiving the deflected liquid.

CECIL ERNEST HARVEY.

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