US1882390A - Centrifugal machine - Google Patents

Description

Oct. 11, 1932. v w, MaclsAAC 1,882,390

CENTR IFUGAL MACHINE Filed March 2l, 1930 3 Sheets-Sheet l Oct. 11, 1932. v W, MaclsAAC 1,882,390

CENTRIFUGAL MACHINE Filed March 21. 1930 5 Sheets-Sheet 2 Oct. 1l, 1932. v. w. MaclsAAc CENTRIFUGAL MACHINE Filed-March 2l, 1930 3 Sheets-Sheet 3 Patented Oct. 11, 193 2 VERNON WESLEY MACISAAG, l' MONTREAL, QUEBEC, CANADA CENTBIFUGAL MACHINE Application med march 21, 1930. serial no. 437,755.

The invention relates to centrifugal machines as described in the present specification and illustrated in the accompanying drawings that form part of the same.

f, The invention consists essentially of the novel means employed of utilizing the kinetic energy of the liquid passing through the machine.

The objects of the invention are to reduce the power customarily necessary to be applied to the machine for the purpose of maintaining the speed of the bowl and for the continual acceleration of the inflowing liquid .to the high velocities necessary for effective development of centrifugal forces therein by usefully reclaiming and directing much of the kinetic energy of the liquid moving at high velocity from the working section or sedimentation section of the machine and of the liquid entering the machine, heretofore ordinarily wasted; and thereby to supplement the usual means of applying power to cause rotation of the bowl and its contents in whole or in part by energy derived from the inflowing liquid to be treated or separated and outilowing liquid after treatment, the energy being supplied to the inflowing liquid either by gravity, by pump or other means of causing pressures and velocity; to cause the separator to act dynamically as a hydraulic turbine within which is provided a section or sections whereby high circumferential velocities are obtainable with slight turbulence and controllable radial thickness for the purpose of centrifugally subsiding desired particles from the mass; to so arrange the structure of the rotating parts that the above objects may be attained without diminishing the effectiveness of the machine as centrifugal separator or classifier; and generally to provide a novel and eilicient means of operating centrifugal machines whereby power may be saved and the means of applying it simplified and cheapened.

In the drawings, Figure 1 is a vertical sectional view showing a rotatable bowl broken away intermediately and constructed for operation in a continuously flowing stream.

Figure 2 is a plan view of the feed end of the machine, showing the stationary inlet member broken away to disclose the spouting passages.

Figure 3 is a plan view at the dischargeend of the machine, disclosing the outlet passages to the recovery impeller.

Figure 4 is a vertical sectional view of a modification of the machine showing a contracted discharge opening with the recovery impellers feature as a supplementary fea-V ture, in maintaining the momentum of the machine.

Figure 5 is a vertical sectional view showing a simple form of turbine containing a separator chamber.

Figure 6 is another modification of the machine showing the application of the recovery impellers to a machine containing a perforated separator drum.

Figure 7 is a diagrammatic view showing the application of a pump in driving a plurality of bowls.

Figure 8 is aplan view of the interior of the cover .showing a turbine feature of the bowl shown in Figure 4. Figure 9 is a plan view partially in section of the outside of the cover showing a turbine feature with a form of the invention shown in Figure 4.

Figure 10 is a plan view of the inlet and partially in section showing the inlet end of the machine illustrated in Figure 4.

Figure 11 is a plan view of the inlet turbine and spouting member of Figure 6J Like numerals of reference indlcate corresponding parts in the various figures. S5

Referring to the drawings, the bowl, indicated by the numeral- 15 is in itself a rotor forming the turbine having the impellers 16 at the feed end and the recovery impellers 17 at the discharge end andV intermediatcly forming the centrifugal chamber of the separator, in which the heavier material is deposited on the inner wall surface by means of the centrifugal force developed in the rotation of the bowl.

This bowl at its lower end communicates with the intake 18 forming a scroll chamber 19 constituting the path to the turbine driving impellers 16 through the spouting passages 20 in said scroll chamber, the divisions 21 forming guiding surfaces as the infiowing fluid impinges on the impellers 16.

The impinging of the liquid on the yturbine impellers 16 tends to set the bowl 15 in motion, and the result is the separation of the heavier particles which are deposited on the wall of the bowl in the customary manner in centrifugal machines.

The bowl 15 is shown as flaring outwardly to form a collecting recess 22 and may or may not have relief pockets from said recess aS. explained more particularly hereinafter, the inturned flange or rim 23 completing the recess 22 and supporting the impellers 17 which are covered in by the ring 24.

The liquid discharges continuously through the passages 25 and is suitably directed to a storage or other receptacle thus by adding this recovery turbine feature recovering energy customarily lost in the ordinary dis- 'j charge of the liquid from a centrifugal maiso chine.

The wall of the bowl 15 may be cylindrical or tapered and is inturned at the inlet end 26. The intake member 18 is rigidly supported by a fixed frame 27 extending from the outer'wall 28 of the scroll chamber 19, the inner wall 29 extending toward the impellers 16.

The turbinefeature carrying the impellers 16 is formed of the flanged ring 30 having upstanding annular flange 31 and the outstanding annular flange 32 forming a recess 33 into which inturned end 26 of the bowl extends, the bowl being 'bolted to the flange 32, thus rigidly securing thel turbine ring and impellers to the bowl.

The bowl 15 is mounted on they main shaft 34 which is journalled in suitable bearings and keyed to the collars or'hubs 34 and 35 from which the radial arms 36 extend to the upper flange 23 of the bowl and are fixed thereto and the arms 37 extend to the turbine ring 30 and are fixed thereto, respectively.

The bowl may be installed to sit vertically, lie horizontally or slope in an intermediate position according to the circumstances of use and it is to be noted that the separating chamber or bowl under all conditions constitutes the momentum member of a driven turbine. In Figures 4, 8 and 9 and 10, the shape of the bowl is changed with consequent changes and additions to meet the different shape.

The bowl 40 is of frusto-conical shape having the inturned outer wall 41 forming a central discharge opening 42 of lesser diameter than the outside measurement of the inner shell 53.

The side wall 44 tapers from the wall 4'1 to the inner wall 43 consequently the thickness of the liquid ringvmust depend on the distance from the edge of the discharge openl ing 42 to the inner surface of the side wall 44 and this would not be practical in accom- .plishing the objects of this invention owing The shell 53 extends from a tubular'mount- A ing 54 keyed to the shaft 45 and slidable thereon and held to the adjusted position by the set screw 55 and having the orifice 56 or orifices to permit a reinforcing wall of liquid to form behind or inside the shell duri-ng the 'operation of the machine.

The shell 53 is of frusto-conical shape corresponding approximately to the bowl in form, but of smaller dimensions, consequent- 'ly forming an annular passage 57 from the inlet end to the discharge end, which assures the reduction in depth of the liquid treated and serves to direct the liquid or lighter material in its path 57 towards the outlet that must be along the inner surfaceof the outer end wall 41.

The impellers 58 project from the inner wall surface of the wall 41 and extend in radial directions to slightly beyond the edge of the discharge opening 42 and are covered in by the ring 59 thus forming an inner recovery turbine feature directly in the path of the discharge.

The thickened wall 60 insures a flat surface in a plane at right angles to the axis of the machine and the impellers'61 project outwardly and across said flat surface in a semispiral direction, thereby forming the outlet passages 62 for the liquid and impact surfaces against which the liquid impinges on its way out and contributing the outer recovery turbine feature for the acceleration of the rotation of the machine at an expenditure of energy of the leaving liquid that otherwise would be wasted. j

The intake 62 encircles the hub 47 and is in the form of a scroll casing 63 having the spouting passages 64 between the curved divisions 65, but this partitioning 'of the scroll chamber is not essential.

The flanged ring 50 extends outwardly to enclose the inwardly extending flange 66 from the scroll casing 63, consequently the passage through to the inlet 51 is guarded and in this intermediate passage the impellers 67 are introduced and these impellers 67 project from the hub 47 and may be the primary driving turbine feature of the machine.

It must be understood that in connection with the primary driving turbine feature and the recovery driving turbine features that one or the other of the features may be omitted, in fact many changes may be made in regard from the spirit of the invention, which amongst other things is to benefit by the skin friction of the llquid on the bowl either in entering or in utilizing the energy accumulating from the high circumferential velocities of the liquid in the machine.

In Figure. 6 the construction shows an adaptation of this invention to the perforated drum t pe of centrifugal machine and in this form tlyie inner shell or liuid conductor 68 is supported by the radia arms 69 and 70 from the hubs 7l and 72 respectively, and this shell is reduced at the outer end 73 to form a primary driving turbine feature preferably having the impellers 74 in the path of the liquid delivered through the spouting member 75, in a nearly tangential direction as shown in Figure 11.

The perforated drum 76 extends at one end from the shell 68 and at the other end from the hub 72 and this drum 76 is surrounded by the casing 77 forming an annular dischar e chamber 78 closed at oneend 79 and lea ing to the annular discharge passage 80 projecting beyond both the perforated drum 76 and casing 77 in a direction at right angles to the axis of the drum and in this passage the impellers 81 are introduced thus orming a recovery turbine feature similar to Figures 3 and 9 through which the liquid must pass and in passing impinge on the impellers 81.

In Figure 5 a very simple form of bowl is shown and indicated by the numeral 82 having the inlet opening 83, through which the spouting member 84 is inserted and directed almost tangentially to the inner wall surface of the bowl 82, similarly to member in Figure 11, the wall of said bowl being inwardly flanged at the discharge end 85 to support the impellers 86 covered by the vring 87. The bowl 82 is supported by the radial arms from the hub 88 keyed to the shaft 89, thus the spouting member 84 may deliver liquid at considerable speed to the bowl to impart rotation thereto and this liquid is treated and finds exit through the passages 90 similar to passages 62 in Figure 9 and recovering energy to aid rotation.

The illustration in Figure 7 is for the purpose of showing the application of the invention to a multiple of machines these machines being indicated by the rotating bowls 91, 92 and 93 mounted on shafts journalled in the bearings 94 and having turbine features 95, 96 and 97 driven by running stream delivered from the pump 98 in the pipes 99,A 100 and 101 branching from the delivery pipe 102 of the pump.

Briefly it may be said that the operation of this invention is mainly concerned in the utilization of the energy gained from the liquid under pressure or high velocity whether from the original stream or from the velocity of the liquid by centrifugal action to an outwardly curved path as enter but reduction of circumferential velocity does, that is to say, in the first place when the liquid is pumped into the machine or when the liquid flows into the machine under an kind of pressure, the primary driving member of the centrifugal machine may be a turbine of any type, in other words, the whole machine becomes a water or liquid wheel driven by th'e flow and in passing through the turbine feature into the interior of the bowl, the liquid drives the machine and is then acted upon by centrifugal force and the heavier port-ion separated from the light portion or the solids from the liquid as the case may be.

YAgain the liquid portion, which is progressing at a very considerable speed, to the discharge due to the momentum of the large body, must seek an outlet, and this outlet is at the discharge end of the machine, therefore, the added force of the throw of the rapidlyA moving liquid is taken advantage of'and it is passed through impellers at the discharge end Where it impinges on the impact faces in passage and .eventually is delivered to the outside, thus much energy that might be otherwise wasted is recovered or as much of it as possible under the circumstances and the efhciency of the machine itself is in no wise altered, in fact if anything still greater eiiciency is secured by the employment of this recovery system.

rIhe impellers in the path of the discharging liquid are beyond the discharge opening and outside of the bowl, forming backwardly and outwardly curved passages through which liquid issuing from discharge opening passes as it is thrown centrifugally outward.

The backward direction of passage causes useful recovery of energy from the leaving liquid tending to aid rotation of the bowl by reactive pressure of the outflowing streams against the forward faces of passages.

This may further be explained by considering a particle of liquid leaving the discharge rim 60, from point O. Its direction of travel if unrestrained would approximate a line OA tangential to the circle of discharge and assuming unrestrained flight over a disc, the particle would trace a path relative to said disc of an involut-e curve from discharge circle as the curve OV while its absolute direction of flight is OA. However, by interposing in its path, deflecting surfaces as shown having a sharply backward direction, the absolute motion of said particle may be defiected from its initial line of flight OA OB being changed in direction and reduced in velocity by the reaction of said defiecting surfaces and thereby pressing them to forward rotation as in a turbine. Indeed this may be considered a final stage of a turbine.

Again returning to inlet the liquid to be centrifugally treated enters under pressure through the inlet and passing aroundthrough the scroll casing 63, which is fixed to the stationary frame of the machine, it is directed inwardly through spouting passages formed between divisions toward the impcller vanes mounted on hub against which vanes the liquid impinges imparting to them a reactive pressure tending torotate hub and shaft and all rotating members thereon mounted. As shown the spouting member comprising scroll casing and divisions between rings provides a plurality of spouting passages, but thls is not always necessary in certain cases.

The liquid entering between impeller vanes is deflected upwardly in the direction ofarrows indicating fiow and is finally centrifugall f thrown outward toward the shell and is discharged centrifugally outward over the edge of the inlet ring towards the wall of the bowl whence it passes along between bowl and inner shell towards the discharge being subjected in this annular section between bowl and shell to an increasing degree of centrifugal force which precipitates out heavier particles from the mixture and deposits them on the inner Wall of the bowl.

This section of the bowl may therefore be termed a sedimentation section. It is to be noted that in a liquid revolving with the bowl of the centrifugal machine the centrifugal forces are commonly from 300 to 500 times that of natural gravity, so that the liquid tends to press outwardly in a ring inside the bowl having an inner diameter approximating the diameter of central discharge opening. And in existing machines intended for the purification of pulp, the minimum thickness of the layer of liquid being treated is determined by the diameter of discharge opening.

Now for the purpose of this invention it is desirable to reduce the diameter of discharge to much less than the inner diameter of the layer of pulp being centrifugally treated at high velocities in thesedimentation section because since the kinetic energy of the liquid leaving the bowl varies as the square of its velocity therefore if it be made to leave at velocities approximating the rim speed of a small discharge opening asv compared with the high velocities near the outer bowl shell remarkable savings in power may be achieved by the recovery of energy as the liquid moves from the section of high velocity to the discharge rim of low velocity. To achieve this result and still be able to constrain the pulp being treated to the comparatively thin layer necessary in centrifugal apparatus, the inner shell is provided with means for adjusting and as before mentioned, the adjustability in the thickness of said layer is attained by` making both bowl and inner shell coneshaped with the inner shell movable endthe crushing pressure from without and v thereby permitting it to be light in construction.

As the liquid travelling at high circumferential linear velocity at the large diameter of bowl moves inwardly towards the discharge opening of less circumferential linear velocity it tends to be slowed up to some eX- tent by friction on the cover wall surface but the invention provides additional and more effective means of reducing this velocity by the provision of impeller vanes between which the outflow towards the discharge may take place restraining the liquid to a velocity approximating that of the discharge rim and reactively causing rotation of the bowl in its passage toward the discharge. This assembly of inner vanes in some instances need not be covered in with a ring.

What I claim is 1. In a centrifugal machine, frusto-conical bowl suitably mounted for rotation and having a feed inlet at one end and discharge at the other end, a frusto-conical inner shell commonly mounted with said outer bowl having an inner deflecting end in the way of the feed inlet, and means for driving said outer bowl.

2. In a centrifugal machine, a frusto-conical bowl suitably mounted on a shaft for rotation therewith and having a central feed inlet at one end and discharge opening at the other end, a frusto-conical shell forming an inner adjustable member slidable on said shaft mounted in respect to said outer casing, and having a bottom end in the way of said feed inlet opening, means for supporting said inner casing and distancing it from the bottom of said bowl and means for driving said shaft.

3. In a centrifugal machine, a frusto-conical bowl, an inner cone-shaped shell spaced 'from the wall of the outer bowl and from the bottom thereof and having a tubular iounting, a shaft for said bowl suitably mounted and carrying said shell and slidably keyed thereto, and a locking means holding,

said tubular mounting and fixedly determining the longitudinal position of said shell.

4. In centrifugal machines, a bowl having inlet and an outlet, and an inner rotary shell forming an annular passage between itself and the inner wall surface 0f the bowl and having a liquid passage into the shell, said shell carrying a defiector adapted to accelerate the How of the liquid in its flow to said annular passage.

5. In centrifugal machines, a bowl mounted on a shaft and having an inlet and an outlet, an intake discharging into said inlet and having a scroll chamber encircling said shaft and causing a swirl in the iniowing liquid adapted to impart motion to the bowl and means for recovering kinetic energy from the bowl discharge.

6. In centrifugal machines, a cylindrical bowl suitably mounted and driven having aA feed end and a central discharge opening in the opposite end, an inner shell of greater diameter than said discharge opening and mounted to rotate with said bowl and forming an annular fiuid passage between said bowl and said shell and having a head for deliecting the incoming liquid-into the annular passage and means of recovering kinetic energy from the liquid adjacent to said discharge opening.

7 In centrifugal machines, a bowl suitably mounted on a rotatable shaft having means to impart rotary motion to said bowl and its contents from the power of incoming liquid and having an intermediate sedimentation section, an inner deflecting shell completing said sedimentation section and adapted to divert the fiow of incoming liquid into any annular ring between said shell and said bowl and to constitute a passage to a central discharge outlet between the shell and the bowl of less diameter than said shell and means of recovering kinetic energy from the liquid leaving said sedimentation section previous to passing said discharge outlet and after passing said discharge and to discharge said liquid from the rotating members at a velocity much less than its linear velocity within the said sedimentation sections.

8. In centrifugal machines, a bowl and a shell spaced to form an intermediate fluid wall directed to the outlet and turbine means 45 having impellers with surfaces receding from the direction of rotation and adapted to form discharge channels in the path of the tan'- gential fiow of the liquid for driving the bowl.

9. In centrifugal machines, a bowl having an inturned flange at the discharge end forming a head encircling the outlet opening, means for driving said bowl. and a shell spaced to form a restricted and shallow pas- 55 sage to the head of the bowl, turbine blades arranged in said outlet for supplementing the driving power.

10. In centrifugal machines, a bowl having an inturned liange at the discharge end form- 60 ing a head and a surface deflecting the discharge of liquid inwardly and a shell cooperating with thist deliecting surface and forming an annular shallow passage from the inlet to the head of the bowl, a turbine mountc5 ed on the inner wall surface of the head in the path of the outgoing fluid, and means for driving the bowl.

11. In centrifugal machines, a bowl suitably mounted for rotation and having an inturned flange at the discharge end, means for driving openings between the blade members supplementing the main driving means. '12. In centrifugal machines, a bowl tapering from an inturned discharge end to an inturned inlet end, a turbine element introduced 1n the path of the liquid liowing into said bowl, a turbine element introduced in the path of the liquid on the inner face of the-inturned discharge end anda turbine element introduced in the path of the liquid on the outer face of said inturned discharge end.

13. In centrifugal machines, a plurality of bowls suitably mounted for rotation and having inturned ends surrounding inlet openings, turbine elements introduced at said inlet ends, stationary inlet chambers encircling said turbine elements land inlet pipe lines leading to said inlet chambers, a feed pipe common to said pipe lines, and a pump connected to a source of supply and forcing iuid into said common feed pipe. i

14. In centrifugal machines, a bowl suitably mounted and driven and having an inturned head to a central discharge opening, means for recovering kinetic energy in the line of the discharge and means for constricting the fluid to a shallow body in passage from the starting end to the inturned head aforesaid.

15. In a centrifugal machine, a bowl suit-- ameterthan said discharge and constricting the Huid to a shallow annular layer within the bowl in passage from the starting end to the inturned head end aforesaid and inwardly projecting vanes mounted within the bowl on the inturned head and with said head constituting channels directing the How of fluid from the aforesaid shallow annular layer towards the discharge opening.

16. In a centrifugal machine, a bowl having an inwardly hanged rim portion forming an overflow member for the comparatively clear liquid, driving turbine blades at said rim, an inlet channel member closing the other end of said bowl and directing the inflow, and driving blades attached to said bowl at the inlet end and introduced in the path of the inflowing liquid.

17. In centrifugal machines, aperforated bowl open at one end suitably mounted for rotation and having a suitable inlet and an outer casing fixed in relation to said bowl and forming a discharge chamber having an annular outwardly extending discharge passage between turbine blades backwardly curved in respect to the direction of rotation to receive a kinetic push from the force of 5 {zhe loutfowing Huid to aid rotation of the Si ned at Montreal, Canada, this 13th day of lfarch 1930.

VERNON WESLEY MAOISAAC.

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