WO1983003596A1

WO1983003596A1 - Method and apparatus for the separation of constituents from a mixture

Info

Publication number: WO1983003596A1
Application number: PCT/FR1983/000069
Authority: WO
Inventors: Robert Jean Perron
Original assignee: Robert Jean Perron
Priority date: 1982-04-14
Filing date: 1983-04-14
Publication date: 1983-10-27
Also published as: DE3340213C2; DE3340213T1; NL8320104A; JPS59500704A; JPH0432705B2; SE8306892D0; SE8306892L

Abstract

Liquid mixture purification by double centrifugal action in the presence of ultrasons. The apparatus comprises a vat (111), a centrifugation means (117) and a ultrasound generator (118) arranged at the center thereof. The centrifugation means consists in a body (117) wherein are arranged at least one inlet conduit (113a) of the liquid to be processed, a plurality of centrifugation channels (117b) which are vertically spaced apart and connecting the vat (111) including said body with the central cavity (124) for collecting the clarified liquid, a plurality of channels (113c) connecting the inlets conduits (113a) with an intermediary point of the centrifugation channels (117b), said central cavity (124) communicating with an outlet conduit (114) for the clarified liquid. Application to separation process for separating constituents from a mixture; purification; cleaning.

Description

METHOD AND APPARATUS FOR SEPARATING THE CONSTITUENTS OF A MIXTURE.

The invention relates to a process for separating the constituents of a liquid mixture, in particular with a view to solving numerous problems of clarification, concentration and industrial pollution. The invention also relates to an apparatus for carrying out this process.

It is frequent that an industrial process leads to the rejection of heterogeneous mixtures, most of the time formed of water extremely charged with solid particles of all kinds, sludge, fibers, etc. The cost of known purification installations often exceeds means of small industries, so that the rivers and the oceans receive daily more and more important quantities of. such waste water.

It is known to use centrifugal force to separate constituents of different densities from an essentially liquid mixture (skimming of milk for example). However, when high quality separation is required, it is necessary to considerably increase the speed of rotation of the centrifuge device. This type of process therefore ceases to be used beyond certain limits, when the disadvantages (difficulties of mechanical implementation and high energy consumption), outweigh the performances.

Furthermore, it is known to clean complex mechanical structures (watch movement for example) by applying ultra vibrations to them. sound. A migration of the impurities towards the outside of the structure is then observed. This process has so far not been successfully applied to liquid mixtures. On the contrary, the formation of an emulsion in the mixture is observed, in other words the opposite of the desired effect.

The invention provides an extremely high degree of separation in a heterogeneous liquid mixture. According to the invention, this result is obtained by the surprising effects of the combination of a centrifugation action and an ultrasound treatment.

More specifically, the invention therefore relates to a process for separating the constituents of a relatively liquid mixture, characterized in that it consists in simultaneously subjecting said mixture to the action of a centiflégation and to the action of a wave. ultrasonic to recover a clarified liquid substantially in the center of the centrifuge field and / or a relatively pasty product outside of it.

The invention also relates to any separation device for a relatively liquid mixture of the type comprising a tank into which said mixture is introduced and a clarified liquid outlet, characterized in that it comprises, in combination, a means of centrifuging said mixture and an emitter of ultrasound.

The combination of these two treatment methods has resulted in the following results:

Centrifugation prevents any emulsion; the ultrasonic treatment therefore resumes in a liquid medium at least the efficiency which it was known for cleaning mechanical structures. In the presence of ultrasound the centrifugation speed can be kept within a reasonable range. To obtain a comparable clarification of the liquid mixture, using only centrifugation, machines rotating four to five times faster than in the case of the invention should be designed. The consumption of additional energy to power the ultrasonic generator is unrelated to that which would be required to drive a centrifuge designed to operate at such speeds. In addition, the investment difference between the high speed centrifuge formula and the solution according to the invention is also considerable, in favor of the latter. A high speed centrifuge indeed requires special bearings and bearings and, in general, a reinforced mechanical infrastructure.

The invention will be better understood and other advantages thereof will appear better in the light of the description which follows of two embodiments of a separator apparatus according to the invention, description given by way of example not limiting and made with reference to the accompanying drawing, in which: - Figure 1 is an elevational view in section of a first embodiment of the separator;

- Figure 2 is a section along II-II of Figure 1;

- Figure 3 is an elevational side view in section of a second embodiment of one invention;

- Figure 4 is a section along lines 1I-II of Figure 3.

Referring to Figure 1, the device separated teur comprises a tank 11 integral with a fixed frame 12, an inlet pipe 13 for the mixture to be treated which opens into the tank at the top thereof, an outlet for clarified liquid 14, extended by a pipe d discharge 15 and a relatively pasty product outlet 16 arranged at the bottom of the tank 11. The orifice 13a of the conduit 13 which opens into the tank will be called the inlet for the mixture to be treated. The tank 11 contains a centrifugation means 17 and an ultrasound emitter 18. They are arranged on an evacuation path towards the outlet 14. In fact, the centrifugation means has the form of a thick disc axially integral with a drive shaft 20 kept mobile in rotation by two rolling bearings 21 and 22 axially aligned and fixed relative to the tank 11. A part 20a of this shaft is hollow to form a conduit for discharging the clarified liquid, from the center of the disc forming the centrifugation means 17 up to the outlet 14. This disc has several radial recesses 23 opening into the tank and communicating internally with a central cavity 24. The hollow part 20a, forming a conduit, of the shaft 20 surmounts the centrifugation means and opens into this cavity 24. The latter houses the ultrasonic transmitter 18, which is held in position by a pole 25 which axially passes through said hollow part 20a and q ui contains the electrical wires supplying the transmitter. The shaft 20 is rotated by a motor (not shown) via a pulley 26-belt system 27. A deflector 28, in the form of a shield, is arranged horizontally between the centrifugation means and the inlet. 13a for mixing. It defines, with a curved internal guide wall 29, of the tank 11, a flow path for the mixture towards the radial recesses 23. The mixture to be treated is injected under pressure through the inlet 13a by means of a pump 30 delivering into the conduit 13. The outlet 16 of relatively pasty product opens into an extractor device 31 with Archimedes screw, actuated on command by an electric motor 32. A maneuverable closure means 33 (movable valve, adjustable restriction, etc.) is placed at a point on the evacuation path of said pasty product. In the example shown, this means is placed at the outlet of the extractor device 31. It makes it possible to maintain a certain pressure inside the tank, in particular to allow it to be filled at the start of operation.

The operation is as follows. The mixture to be treated is injected under slight pressure into the tank 11, by the action of the pump 30, until sufficient filling of the tank. The centrifugation means 17 is then rotated and the ultrasonic transmitter 18 is supplied. By adjusting the flow rate of the pump and the position of the shutter means 33, it is possible to cause a controlled flow of liquid through the outlet 14, since the latter can go back up through the conduit 20 by crossing the radial conduits 23 and the central cavity 24 in which it is subjected simultaneously to centrifugal force and to the action of ultrasound.

The lower the flow rate, the more the liquid comes out. During this time, a relatively more pasty residue accumulates at the bottom of the tank 11. It is removed from time to time by using the extractor device.

FIG. 3 represents another embodiment of the device, the structure of which makes it possible to significantly increase the performance of the device both with regard to the flow rate and with regard to the quality of treatment, without significantly increasing its bulk.

Referring to Figure 3, the apparatus shown comprises a substantially cylindrical tank 111 defined by a bottom forming support 112a, resting on the ground by suitable feet, a cylindrical side wall 112b and a flat cover 112c Inside the tank 111, axially aligned with it, is arranged a centrifuge means 117 with axial symmetry, constituted by a body provided with frustoconical fins 117a. A cylindrical interior cavity 124 extends coaxially by means of centrifugation 117, and a plurality of horizontal radial channels 117b extending between said cavity 124 and the tank 111, arranged in stars with six regular branches superimposed on each other in the body 117 of the centrifugation means, the ends on the tank side of the channels 117b opening at the outer radial ends of said fins. As many fins are provided as stars with six conduits, and these are seven in number in the present example.

In the body 117 of the centrifugation means are further provided six cylindrical conduits 113a extending substantially over its entire axial length and distributed evenly at the periphery of the recessed edges of the fins. The conduits 113a communicate via channels 113c with the radial channels 117b and distribute the product to be treated to the different stages of the device. The six vertical conduits 113a communicate at their lower end with a central inlet conduit 113b, which itself communicates with a conduit 113 provided for the introduction of the mixture of heterogeneous liquid to be treated. The conduit 113 is connected to the outlet of a pump (not shown).

The inner cylindrical cavity 124 is connected at its upper end to a coaxial outlet conduit 114, which itself communicates with a conduit 115 provided for the outlet of the clarified liquid.

In addition, in the bottom wall of the tank 111 is formed an outlet orifice 116 for the pasty product. The outlet orifice 116 can, like the outlet orifice 16 (fig. 1) lead to extraction means with an Archimedes screw, and to operable shutter means.

The lower 113b and upper 114 ducts respectively define bearing shafts 120a, 120b of the centrifuge means 117, which are rotatably mounted in associated coaxial roller bearings, respectively 122, 121. The centrifuge means 117 is driven in rotation suitably around its axis by a pulley 126 and a belt 127, itself driven by an electric motor 128 fixed to the part of the lower support of the assembly 112a by a suitable frame or frame. Finally, in the cavity 124 is housed an ultrasonic transmitter 118 in the form of a bar.

The operation of the apparatus is as follows: the heterogeneous liquid to be treated is introduced under an appropriate pressure into the tank 111, by means of the pump mentioned above. For proper filling of the tank, the seven-stage centrifugation means 117 is rotated, and the ultrasonic transmitter 118 is powered. Under the action of pressure, the fluid rises through the conduits 113a and through the passages 113c it enters the body 117 where it is subjected to the combined action of centrifugation and ultrasound, which makes it possible to obtain a separation of high quality with a reasonable rotation speed. Under the effect of this combined action, the clarified liquid enters the cavity 124 through the channels 117b and its inherent pressure causes it to rise to the outlet conduit 114 from which it passes into the conduit 115. On the other hand , the pasty product obtained accumulates in the lower part of the tank 111, from which it is extracted at the outlet 116.

The apparatus according to the present invention makes it possible in particular to solve the following industrial problems:

- Purification of white water from paper factories. It is thus possible to retain the fibers (which form the pasty residue) before discharging the water into the river.

- Treatment, before rejection, of the blood of animals in slaughterhouses. You can extract the water of constitution and recover the rest in the form of a pasty concentrate. It should be noted that currently this blood is treated in evaporators, the cost of installation is very high and the operation energy expensive. In general, this installation provides a satisfactory solution to all the problems of treating waste water with low-cost means and small footprint. It is particularly suitable for pretreatment in major pollution control systems. It then reduces the overall cost.

Another interesting application relates to treatments using flocculants. Thanks to the apparatus of FIG. 1, the action of the flocculents is considerably accelerated and increased, thus allowing a substantial reduction in the quantities of flocculants required. To use the device with flocculent injection, it is necessary to complete the installation with a flocculants 35 and a circuit comprising a small pump 36 and an injection pipe 37 opening into the pipe 13.

The apparatus shown in FIG. 3 comprises a centrifugation means including several individual superimposed centrifugation units, formed of one piece or of a plurality of individual centrifugation units, making it possible to increase the flow rate of the apparatus in significant proportions and improve the quality of the treatment, without however significantly increasing its size. It can be used industrially in all the applications intended for this kind of device.

It can be used in particular when it is a question of treating without denaturing them by the addition of flocculents of products such as milk, blood, eonserie food products, drinks.

To this end, magnetic means such as permanent magnets or electromagnets (130 Fig. 3 and 4) can be added to the centrifugation means associated with the ultra-thin transmitter, for example located on the periphery of the cylindrical longitudinal wall of the tank, the magnetic field generated by these magnets having the effect of determining an internal tension of the product, from which results, under the effect of ultrasound, the separation of the constituents.

In the case of liquids including components in solution, in order to obtain a total separation, one could, under the same conditions, add to the apparatus microwave generating means (magnetrons), arranged at the periphery of the tank. to determine an overheating of the liquid to be treated, so as to determine, as a result of the increase in the density difference of the constituents which it causes, the required separation of the latter.

It is understood that the invention is not limited to the embodiment described and illustrated, and that any modifications may be made to the shape and to the number of the constituent elements of the device without departing from the scope of the invention .

Claims

1. Method for separating the constituents of a relatively liquid mixture, characterized in that it consists in simultaneously subjecting said mixture to the action of centrifugation and to the action of an ultrasonic wave to recover a liquid clarified substantially at center of the centrifuge field and / or a relatively pasty product on the outside thereof.

2. Separator for a relatively liquid mixture of the kind comprising a tank (11) into which said mixture is introduced and a clarified liquid outlet (14), casctérisé in that it comprises in combination a means of centrifugation (17) of said mixture and an ultrasonic transmitter. (18).

3. Separator according to claim 2, characterized in that the centrifugation means (17) and / or the ultrasonic transmitter (18) are arranged on an evacuation path towards the outlet (14) of clarified liquid.

4. Apparatus sebn claim 1 or 2, characterized in that the ultrasonic transmitter is placed substantially in the center of the centrifugation means.

5. Separator according to one of claims 2 to 4, characterized in that said centrifuging means has there the form of a thick disc axially integral with a drive shaft (20), in that this disc comprises several radial recesses (23) opening into said tank and communicating internally with a central cavity (24), in that a part of said shaft (20a) is hollow and opens into this central cavity and in that said hollow part crosses the wall of the tank for materializing said clarified liquid outlet (14).

6. Separator according to one of claims 2 to 4, characterized in that the centrifugation means consists of a body (117) in which are formed at least one inlet conduit (113a) of the liquid to be treated, a plurality vertically spaced centrifuge channels (117b), communicating the tank (111) including said body with the central cavity (124) for collecting the clarified liquid, a plurality of channels (113c) interconnecting the inlet conduits (113a ) with an intermediate point of the centrifuge channels (117b), said central cavity (124) communicating with an outlet conduit (114) for the clarified liquid.

7. Separator according to claim 6, characterized in that the body (117) has fins, the centrifuge channels (117) extending between the outer edges of said fins and the central recovery cavity (124).

8. Separator according to claims 6 and 7, characterized in that the centrifuge channels (117b) are angularly distributed around the axis of the centrifuge means.

9. Separator according to claims 2 5 and 6, characterized in that the central cavity (24 fig.1 and 124 fig.3) includes the ultrasonic transmitter.

10.Separator according to claims 5 and 6, characterized in that a pasty product outlet (16 fig.1 and 116 fig.3) is arranged at the bottom of the tank (11 fig.1 and 111fig.3) and that this outlet leads into an extractor device with an Archimedes screw.

11. Apparatus according to claim 10, characterized in that an operable shutter means or the like is placed at a point in the path of evacuation of said pasty product, for example at the outlet of said extractor device.

12. Apparatus according to one of claims 2 to 5, 10 and 11, characterized in that a deflector means (28) is disposed between the centrifugation means and an inlet (13a) for said mixture, and in that this deflector defines with an internal guide wall (29) of the tank a flow path from said mixture to said centrifugation means.

13. Apparatus according to one of claims

2 to 12, characterized in that an injection pump for said mixture is placed upstream of the tank.

14. Apparatus according to one of claims

2 to 6 and 10 to 13, characterized in that it comprises means for injecting (36,37) flocculent into said tank.

15. Apparatus according to claim 6, characterized in that the body (117) constituting the centrifugation means is formed in one piece.

16. Apparatus according to claim 6, characterized in that the body (117) constituting the centrifugation means is formed by the superposition of a plurality of individual centrifugation units.

17. Apparatus according to claim 6, characterized in that magnetic means are arranged at the periphery of the longitudinal wall of the tank (111) so that the magnetic field generated determines an internal tension of the mixture to to treat, from which results under the effect of ultrasound the separation of the constituents to said mixture.

18. Apparatus according to claim 6, characterized in that microwave generating means (magnetrons) are arranged at the periphery of the cylindrical longitudinal wall of the tank to determine a heating of the molecules of the liquid mixture to be treated, from which results, due to the increased density difference of the constituents of the mixture, the required separation of the latter.