US2098608A - Apparatus for the purification of miscellaneous liquid mixtures - Google Patents

Description

Nov. 9, 1937. A. BERGES 2,093,608

APPARATUS FOR THE PURIFICATION OF MISCELLANEOUS LIQUID MIXTURES Filed March 12. 1956 I INVENTIJR ANDRE 35mm Patented Nov. 9, 1937 UNITED STATES APPARATUS FOR THE PURIFICATION OF MISCELLANEOUS LIQUID MIXTURES Andre Bergen, L 1, M69

Application March 12, 1936, Serial No. 88,535 In France March 14, 1935 Claims.

The present invention has for its object a device for the continuous purification and classification of miscellaneous liquid mixtures and in particular for paper pulp'.

Purifying devices for paper. pulp are known in which there is merely centrifugal extraction of the heavy impurities of the pulp. In these arrangements the paper pulp passes tangentially into a fixed conical receiver where it receives a gyratory movement. "An adjustable opening allows continuous discharge of the impurities at the upper periphery of the receiver. The pulp leaves by a central tube. Apparatus of this type allow neither the extraction of the light impurities nor the proper classification of the material which is treated therein.

Other arrangements comprise a fixed cylindrical sieve on the interior surface of which is projected the pulp, which is axially delivered, whilst being thrown back from the conical deflecting surfacw. Diluting water is similarly separated and projected on the sieve by the same means. These apparatus are merely sifters and not classifiers. In addition they cause the undesirable dilution of the pulp due to the water thus introduced.

In addition rotating sifters are known in which conical members, which rotate with the sieve, form ballie plates which distribute the mass to be treated over the entire sifting surface, which is likewise conical under the effect of centrifugal force. The axle which supports these cones is hollow and perforated with holes through which the washing water can be intermittently introduced into the device. As in the previous cases this device can only provide two varieties of product; that which is retained inside the sieve and that which can pass through it. Neither works by gravity. 7

The purifying and classifying apparatus forming the object of the invention is essentially characterised by several hollow cones, open at the bottom, which are disposed in series inside a fixed and closed receiver below the pulp exit pipe coaxially to the receiver and fixed to a discharge pipe which is provided with openings which discharge into the interior of the said cones. This apparatus is primarily intended to rid various liquid materials, and in particular paper pulp, not only of the heavy impurities but also light impurities by continuous centrifuging and not by sifting. In the same way it can also serve to classify these materials in their order of density.

The material to be treated, which comes at .high speed tangentially to the interior wall of the fixed receiver fills it completely at regular intervals and all the exits for the material start from the centre of the receiver.

The special arrangements of cones is intended to create from the periphery of the mass occupying the receiver, to the centre of the same, a descending current the eifect'ofwhich adds to that of the weight in order to cause the deposit of the heavy impurities at the lower part of the said receiver from whence they are evacuated by a special passage.

Moreover these cones prevent the central turbulence, (typhoon effect) due to the high speed of the liquid, from forming between the base of the apparatus and the upper exit of the purified mass.

It is thus possible to increase the speed of circulation of the material in the apparatus (up to or beyond 30 m/s instead of approximately 5 m/s in the normal apparatus) in order to multiply the efiects of the centrifugal force, and therefore the differences in density and to obtain in this manner in addition to a better delivery in the apparatus, all other things being equal, a more eflicient separation and classification.

The attached drawing shows by way of example one form of construction of a static and continuous purifying apparatus for paper pulp, constructed according to the invention.

Fig. 1 is a vertical section of the apparatus,

Fig. 2 is a part section on the line A-A of Fi l.

The apparatus is formed of a fixed metal container comprising a cylindrical portion l and on its upper and lower extremities truncated parts 2 and 3. The part 2 is surmounted by a cylindrical portion 4 of small diameter on which is fixed the tangential delivery opening 5 of the pulp to be purified.

Inside the cylinder 4 is disposed a truncated portion 6 connected to a pipe and is intended to collect and discharge the liquid charged with light impurities. A pipe 8 disposed about the vertical axis of the apparatus and reaching down to the cylindrical part I serves to collect the purified pulp.

The truncated part 3 terminates at this lower end in a discharge pipe 9. This device can be operated continuously (tube connected to 'decantation boat) or intermittently (chamber connected to the boat for collecting the heavy material). A series of cones i0, H, l2, I3 is disposed along the axis of the apparatus in the parts I and 3. These cones are mounted on a tube l4 connected to another tube l5 which discharges outside the apparatus. Holes I6 connect the interior of the cones with the interior .of the tube l4.

The method of operation of the apparatus is as follows:- P

The pulp to be purified is carried along by means of a pump (not shown) and is delivered at 5 at a high speed in the region of 20-40 metres per second. This tangential delivery of the pulp i parts a rapid rotating movement to the liquid inside the container l-2-3-4. Under the effect of centrifugal force the heavy materials are thrown on the wall l-2 from whence they descend along the wall 3 to 9 where they are discharged.

The lighter materials remain in suspension in the liquid but although acted on to a certain extent by a centrifugal force they do not quite reach the wall of the apparatus. They are collected by the cone 6 and are continuously discharged by the pipe 1. They are conducted to a decantation boat not shown, the liquid regained after the deposit of the impurities returns to manufacture.

Purifiedpulp is collected by means of the pipe 8 in the centre of the apparatus. It is supplied direct for manufacture.

The superposed cones ,lll, Ii, I2, I 3 which are disposed at the lower part of the fixed container I along its axis prevent the heavy material from being carried along by the current created by the discharge tube 8 for the purified pulp. Pipe i4--|5 serves at the same time to support the cones ill-43 and to ensure the clearing of the said cones and the discharge of a small portion of the paper pulp.

If the liquid or fluid movement in the cylindrical portion situated below the opening of the' pipe 8 is examined from a theoretical point of view it may be seen that its molecules are acted upon by three forces.

(a) By a centrifugal force C which classes them in order of density W V2 C-?X'I (this force is comparatively large compared with the two others since V is large).

(b) By the force f due to the movement of the liquid created by the discharge of the pipe 8.

(c) By the action of the weight 1).

If a descending movement is imparted to the centre of the liquid a new force P will at the same time be created and will add to that of the weight p. This descending movement results from the efi'ect oi the pipe I4i5 and that of the openings which are provided on this pipe, inside the cones, and at a higher level than that of their edge. The pipe l4, l can also be directed towards the lower part as well as the upper part. In this case it is placed concentrically to the pipe 8. Only the cones need to retain the position indicated. The tendency of the heavy materials to separate which is due to p and C will be increased in proportion to this new force P.

At no moment in the course of their descending movement can the heavy particles be acted upon by the force opposed to the two forces p, P.

The apparatus described above is merely indicated as an example of construction of the invention. It may comprise any desired variation in construction as well as any suitable modifications as may be required for the purification of the liquid mixture.

It is obvious that this apparatus as described may be applied to any separation of miscellaneous liquids in addition to paper pulp.

I claim:

1. A device for the continuous purification and classification of heterogeneous liquid mixtures, comprising a fixed closed receptacle of circular cross-section, an inlet conduit arranged tangentially to said receptacle and adapted to maintain the receptacle filled with the liquid mixture under pressure, an upper central conduit for upwardly discharging part of the liquid mixture, a lower central conduit, having its upper end below the lower end of the upper central conduit, for downwardly discharging another part of the liquid mixture, said lower conduit having lateral openings therein traversed by the part of the liquid discharged through the lower conduit, and a plu rality of superposed hollow cones mounted on the lower conduit adjacent the openings.

2. A device for the continuous purification and classification of heterogeneous liquid mixtures, comprising a fixed closed receptacle of circular cross-section, an inlet conduit arranged tangentially to said receptacle and adapted to maintain the receptacle filled with the liquid mixture under pressure, an upper central conduit for upwardly discharging part of the liquid mixture, a lower central conduit, having its upper end below the lower end oi the upper central conduit, for downwardly discharging another part 01 the liquid mixture, said lower conduit having lateral openings therein traversed by the part oi! the liquid discharged through the lower conduit, and a plurality of superposed upwardly-pointing hollow cones mounted on the lower conduit, the openings 01' said lower conduit being above the lower edges of the associated cones.

3. A device for the continuous purification and classification of heterogeneous liquid mixtures, comprising a fixed closed receptacle of circular cross-section, an inlet conduit arranged tangentially to said receptacle and adapted to maintain the receptacle filled with the liquid mixture under pressure, an upper central conduit for upwardly discharging part of the liquid mixture, a fixed lower central conduit closed at its upper end, axially arranged in the receptacle and having at its lower end an outlet outside the receptacle, said lower conduit having its upper end below the lower end of the upper conduit and having superposed inlet openings in the side walls, and upwardly directed conical baifles disposed with their lower edges at lower levels than the adjacent inlet openings.

4. A device according to claim 3, in which the top of the lower conduit is closed by the uppermost conical baille the point of which is located below the inlet of the upper conduit.

5. A device for the continuous purification and classification of heterogeneous liquid mixtures, comprising a fixed closed receptacle of circular cross-section, an inlet conduit arranged tangentially to said receptacle and adapted to maintain the receptacle filled with the liquid mixture under pressure, an upper central conduit for upwardly discharging part of the liquid mixture, a fixed lower central conduit closed at its upper end, axially arranged in the receptacle and having at its lower end an outlet outside the receptacle, said lower conduit having its upper end below the lower end of the upper conduit and having superposed inlet openings in the side walls, and upwardly directed conical bafiles disposed with their lower edges at lower levels than the adjacent inlet openings and spaced from the wall of the receptacle by distance greater than the maxim diameter of the cones.

ANDRE BERGES.

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