FI69766B - FOERFARANDE OCH ANORDNING FOER MATNING AV ETT SPOLNINGSMEDIUM TILL VIRVELSEPARATORER - Google Patents

Description

69766

A method and apparatus for feeding a rinsing medium to vortex separators. -Förfarande. och anordning för matning av ett spcl ningsmedinm account virvel-scparatorer.

The present invention relates to a method and apparatus for feeding a rinsing medium to vortex separators in which two or more parallel vortices are connected in pairs to each other through an opening as the vortices rotate in opposite directions, whereby the vortices are caused to collide and support each other.

The term "medium" as used in this specification is intended to include powdered and fibrous flowing solids, flowing liquids, liquid droplets and gases, and various mixtures thereof. Accordingly, the term "particle" is intended to include solid particles, liquid droplets, liquid molecules, gas molecules and gas atoms, and gas bubbles.

The term "rinsing medium" as used herein is intended to include all media except those that are primarily intended to be distinguished from one another. The rinsing medium can thus mean, for example, a diluent or a medium which produces a chemical or biological effect.

Several vortex separators are already known, in which the rinsing medium is introduced into the outer part of the vortex. For example, U.S. Patent No. 2 S29,771 discloses a vortex separator which primarily seeks to separate coarse and fine solid particles in an aqueous slurry. In this example, dilution water is used as the rinsing medium, which is led tangentially from the tubes to the cyclone cone. U.S. Patent 3,337,050 seeks to distinguish primarily good pulp fibers as well as impurity particles in an aqueous slurry. In this case, the dilution water acting as a rinsing medium is led tangentially to a separate rinsing chamber. The conduction of dilution water to the cone is disclosed in FI patent 31045. The conduction of dilution water through a porous cone wall is disclosed in GB patent 1,177,176.

The introduction of a diluent into the outer part of the separating vortex from a diluent vortex of 2,697,600 is known from U.S. Patent 3,754,655.

A pneumatic classifier for separating coarse and fine particles is disclosed in U.S. Patent 2,767,840. The flushing medium is then air which is tangentially introduced into the vortex chamber.

The introduction of flotation into the vortex chamber by means of rinsing air from small slits is disclosed in GB Patent 1,005,479. In this case, the primary aim is to separate the mineral particles from one another.

Belgian patent publication 894 830 discloses a solution in which adjacent separating vortices support each other without a partition wall. The same publication discloses the conduction of a mixture to be separated between vortices. Finnish patent application 830199 presents the principle of vortex series separation.

A disadvantage of the known flushing solutions is the complexity and high cost of the structure, since each vortex chamber needs its own conduit connections and channels for conducting the flushing medium. Also, the rinsing medium is not evenly distributed in the outer portions of the evenly separating vortex into a thin layer. In addition, a disadvantage of the known solutions is that the local supply of the rinsing medium in a relatively thick layer creates disturbances to the separating vortex as turbulence. In known solutions, the rinsing medium is usually led in the vicinity of the wall, where friction slows down the rotation, whereby disturbing speed differences between the rinsing medium and the separating vortex are easily created. It is as if the rinsing medium has to be forcibly pumped at a higher speed into the slow outer part of the separating vortex. The friction of the wall generates a small disturbing turbulence, which in turn breaks the thin film of the rinsing medium, causing some of the rinsing medium to escape too quickly in turbulent vortices towards the center of the separating vortex without performing the desired rinsing function.

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Due to the cumbersome construction of the rinsing medium supply lines, the rinsing medium is most often only applied to a small part of the total height of the separating vortex, whereby the rinsing effect remains local and inefficient. With known solutions, it is not possible to vary the thickness of the rinsing layer at different points in the vortex.

The object of the present invention is to reduce the above-mentioned drawbacks and is achieved by the method according to the invention by feeding the rinsing medium between the vortices at a point where the vortices rest against each other.

The devices for carrying out the method according to the invention are set out in the claims below.

The invention can be applied to a wide variety of separation tasks using vortex separation. According to the invention, the rinsing medium can, in addition to the actual vortex separation, also perform other process tasks, e.g. physically, chemically or biologically.

The invention is illustrated by the following figures.

Figure 1 shows a conical vortex separator pair according to the invention, in which the rinsing medium is passed between the cones.

Figure 2 shows a pair of vortex separators according to the invention, in which the rinsing medium is passed between the cylinders.

Figure 3 shows a schematic cross-sectional view at III-III in Figures 1 and 2.

Figure 4 shows a vortex separator with four vortices, which includes one rinsing medium inlet pipe.

Figure 5 shows in principle a section along the line V-V in Figure 4.

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Figure 6 shows a section of a vortex series separator according to the invention.

Figure 7 shows a section along the line VII-VII in Figure 6.

Figure 8 shows in principle the flow field and the distribution of the rinsing medium in the vortex pair.

Figure 9 shows a sectional view of a vortex series separator according to the invention.

Figure 10 shows a sectional view of an embodiment of a vortex series separator according to the invention.

It is a central object of the present invention to simplify and streamline the supply of rinsing medium to the vortex separators. According to the invention, the piping can be considerably reduced, whereby the manufacture of the devices is facilitated and the price is reduced. This, in turn, makes it possible to use rinsing media on a larger scale than before in vortex separation, which can improve the resolution in many cases quite a lot.

By guiding the rinsing medium between the vortices, the layer of rinsing medium to be fed is further divided into two parts, whereby the layer thickness of the rinsing medium is made very small, if desired. This, in turn, allows reasonable amounts of rinsing medium to surround even the entire separating vortex at full height. In this way, a mattress of rinsing medium is formed in the layer of slow movement in the vicinity of the walls, which in a way lubricates the actual separating vortex on all sides. In this way, the separable medium particles cannot get stuck in the walls, which would impair the separation result. Due to the reduced friction, the speed in the actual separating vortex is made high.

According to the invention, the rinsing medium is caused to pass 69766 evenly and relatively slowly from the outer parts of the separating vortex towards the central parts, whereby the desired particles are entrained with the rinsing medium into the central parts of the vortex.

By making the rinsing medium feed height high, the rinsing medium feed can accelerate the actual separating vortex without detrimental speed differences at different elevation levels.

The arrangement according to the invention also allows the rinsing medium to enter the vortex at exactly the same speed at which the outer parts of the separating vortices move. When the parallel separating vortices collide gently with one another at the feed point according to the invention, they create a suction effect which naturally regulates the inflow of the rinsing medium. The suction effect also reduces the required pumping energy.

Getting the rinsing medium into a thin and wide layer promotes contact between the vortex and the rinsing medium. In this case, e.g. desired e.g. physical, chemical or biological events between the rinsing medium and the vortex. Examples of such applications are wastewater aeration, flotation, and flue gas scrubber application in vortex separators.

According to the invention, the layer thickness of the rinsing medium can be easily controlled at different height levels of the vortices simply by making the width of the rinsing medium supply channel vary at different height levels in the vortices.

With the arrangement according to the invention, even large amounts of rinsing medium can be fed to the vortices if desired. For example, strong dilution greatly improves the separation result.

With the arrangement according to the invention, the flows between the different vortex chambers can be controlled. Likewise, the ability of the various 6 69766 particles to move from one vortex chamber to another can be controlled.

The following figures show by way of example some embodiments of the invention and illustrate the operation of the invention. In reality, a large number of different embodiments can be found for the invention. The shapes and dimensions of the devices according to the invention are selected according to the respective application. The choice can be made through experimental studies and theoretical examination in different situations.

The names of the parts shown in the figures are 1. the wall of the vortex chamber 2. the general direction of movement of the vortex 12. the tangential feed channel for the medium to be distributed 13. the light component discharge pipe 14. the axial discharge pipe of the heavy component 39. the flow divider to separate the different vortices. vortex chamber cover 68. vortex chamber bottom 70. heavy component tangential discharge passage 71. heavy component principal trajectory 80. rinsing medium supply passage to vortex chambers 81. rinsing medium inlet pipe 90. interface between different vortex modes

Figure 1 shows a rinsing medium supply arrangement according to the invention, in which the rinsing medium supply channel 80 is guided between two conical vortex chambers 1. In the case of Fig. 1, the flushing medium is introduced only into the lower part of the conical vortex chambers 1, where, for example, the thickening generally tends to be strongest. The actual mixture to be separated is passed to the wider end of the cones in this case along the tangential feed channel 12 also between the conical vortex chambers 1. In the case of Figure 1, channels 80 and 12 are parallel.

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Figure 2 shows a rinsing medium supply arrangement according to the invention, in which the rinsing medium supply channel 80 is guided between cylindrical vortex chambers 1. In this case, the rinsing medium supply channel 80 is immediately below the mixture supply channel 12 to be separated. In this case, the mixture to be separated, when it enters the helical motion path, drifts after one full revolution at the supply channel 80 of the rinsing medium, whereby the rinsing medium covers the vortex 2 from the outside. The same is repeated in several turns when the height of the rinsing medium supply channel 80 is a multiple of the height of the mixture feed channel 12 to be separated, which determines the pitch of the helical thread. Thus, with each round, the rinsing medium is added to the outer part of the vortex 2, which enhances the desired effect.

Figure 3 illustrates the flow situation at the rinsing medium supply pipe 80 in the devices of the previous figures. The vortices 2 rotate in opposite directions so that at the opening 40 the direction of movement of the different vortices is the same. The rinsing medium is fed from the channel 80 between the vortices 2 at the opening 40. If the rinsing medium supply channel 80 is directed slightly obliquely against the vortex shaft, e.g. from above, a movement component in the direction of the vortex axis is obtained for the rinsing medium. In this way, the movements in the outer parts of the vortices 2 in the direction of the vortex axis can be emphasized and intensified if desired. This is advantageous, e.g., in guiding the coarse fraction towards the tip 14 of the cyclone cone in the outer vortex. By orienting the rinsing medium supply channel 80, the ratio between axial movements and rotational movements can be adjusted as desired. Without special measures, the helical-helical movement in the cyclone cone usually tends to turn too early into an internal vortex towards the outlet pipe 13. The separation result is then often incomplete. This problem can be reduced by a supply flow of rinsing medium having a motion component in the direction of the vortex axis.

Figure 4 shows a rinsing medium inlet pipe 81 69766 in a separator comprising four vortices 2 according to an embodiment. According to Figure 4, only one rinsing medium supply pipe 81 is required, although there are four vortices. This shows the simplicity of the structure.

Figure 5 is a sectional view of the device shown in Figure 4. The rinsing medium supply pipe 81 is shaped inside the device in the shape of a flow divider 39 in cross section. By making two slits in the tube 81 as rinsing medium supply channels 80, it has been possible to form a fairly simple rinsing medium supply arrangement. The flow divider 39 can consist of e.g. two corner profiles with gaps 80 between them. The distance between the halves of the flow divider 39 can be made adjustable e.g. by a screw, whereby the width of the channels 80, i.e. the layer thickness of the rinsing medium, can be adjusted. The flow divider 39 can also be formed, for example, from two halves of a circular tube with gaps 80 between them. The extent of the channels 80 in the direction of the vortex axes is freely selectable. Often, the channels 80 can be extended over the entire cylinder height.

Figures 6 and 7 show a vortex series separator, where successive vortices 2 rest on each other. According to the invention, rinsing medium is fed to some of the abutment areas 40 from the channels 80. In the case shown in Fig. 6, the rinsing medium inlet pipe 81 is parallel to the vortex axis and has a longitudinal slit forming the rinsing medium supply duct 80. . It is preferable to supply the rinsing medium in particular in the vicinity of the cover 47 or the base 68, where the friction of the cover 47 and the base 68 slows down the vortex movement, whereby even the heavy component can easily enter the light component outlet pipe 13. The abundant amount of rinsing medium at this point reduces said malfunction. The rinsing medium supply channel 80 can therefore be placed, for example, in the vicinity of the lid 47 or the base 68. The channel 80 can be made to increase in width towards the cover 9 69766 47 or the bottom 68, whereby the flow rates of the rinsing medium increase at these points. The amount of flushing medium supply in the channels 80 can be controlled by changing the pressure levels in the pipes 81, e.g. by means of control valves. By varying the amount of rinsing medium and the feed rate, the operation of the entire vortex separator can be controlled. By directing a large amount of rinsing medium to the end of the series, the transport of small or light particles to the end can be effectively limited when the 2.2 ... transverse jets of rinsing medium break the path from them. Larger and heavier particles, on the other hand, can more easily pass through jets of rinsing medium.

Figure 8 shows how the flow from the rinsing medium supply duct 80 is further divided into two parts, which can be very thin. Figure 8 also shows how the interlocking vortices 2.2 constrict in the vicinity of the opening 40 when the interface of the vortices 2 is flat and the inner parts of the vortices 2.2 are circular. The constriction causes a strong increase in velocity at the orifice 40, which lowers the pressure and creates a suction effect in the channel 80. This suction effect facilitates the supply of the rinsing medium to the vortices 2 and tends to adjust the velocity itself.

Figure 9 shows a wider vortex series separator than Figures 6 and 7. A portion of the flow dividers 39 act as double-sided flushing medium supply channels, with the portion 80 being single-sided. The feed direction of the rinsing medium is always shown in the figures downstream of the vortices, but it is also possible to feed the rinsing medium between the vortices 2 against their direction of movement. In this case, however, the feed rate must be very low so that the vortex movement is not stopped. With this special arrangement, local turbulence can be generated, for example, to break the dense network formed by the paper fibers. The rinsing medium supply channel 80 can be filled with a porous material so that the rinsing medium can, if desired, be finely divided and gently swirled 2. The supply channel 80 can be replaced, if desired, by separate supply pipes which can be placed one on top of the other. If these supply pipes are provided with nozzles, the rinsing medium can be fed at a very high speed and caused to disperse, for example, into a fine mist. In this case, for example, sulfur dioxide (SC2) can be removed from the flue gases by means of a neutralizing mist curtain sprayed between the vortices 2, 2. The mist may consist of, for example, lime sludge droplets.

Figure 10 shows an arrangement in which the rinsing medium supply channels 80 are inclined with respect to the interface 90 between the different vortex states. In the vortex series separator, the amount of flow flowing from the vortex 2 to the next can then be easily controlled by controlling the flow of the rinsing medium. The operation of the device can be emphasized at the beginning or end. The solution according to Figure 10 is advantageous, e.g. in pneumatic classifiers, when forming air barriers for small particles.

By controlling the feed rate and amount of rinsing medium, the classification limits of the device can be easily changed between different fractions. The oblique position of the rinsing medium supply channels 80 with respect to the interfaces 90 between the different vortex states is advantageous, because then the compression of the flow to the end of the vortex series 2,2 ... can be effectively prevented. Channel 80 is shown in the figures as a caricature wide. Often only very narrow slits 80 are needed.

The large double-sided contact surface enhances, for example, the heat transfer between the medium to be separated and the rinsing medium. Thus, the rinsing medium can be used to recover heat from the mixture to be separated or to cool the mixture to be separated. Chemical reactions are also facilitated by two-way contact.

Sudden changes in velocity due to constriction (cf. Fig. 8) cause particles of different masses to have different accelerations, which also facilitates contact due to mutual velocity differences.

Claims (20)

A method for feeding a rinsing medium to vortex separators, wherein two or more parallel vortices (2) are connected in pairs to each other via an opening (40) with the vortices (2) rotating in opposite directions, said vortices being caused to collide and support each other, characterized by that the rinsing medium is fed between the vortices (2) at a point where the vortices rest against each other. Method according to Claim 1, characterized in that the transfer jet of the rinsing medium is used to control the movement of the particles from one vortex to another. Method according to Claim 1, characterized in that the rinsing medium is fed between the vortices (2,2) parallel to the vortex flow. Method according to Claim 1 or 2, characterized in that the rinsing medium is fed between the vortices (2,2) tangentially against the vortex flow. Method according to one of Claims 1 to 4, characterized in that the width of the supply channel (80) is adjusted. Method according to one of Claims 1 to 5, characterized in that the pressure of the rinsing medium supply pipe (81) is adjusted. Method according to one of Claims 1 to 6, characterized in that the supply flow of the rinsing medium is controlled in a direction which forms an angle (α) with the interface (90) between the vortex states (40). A method according to any one of claims 1 to 7. i2 69766 characterized in that a vortex axis movement component is applied to the supply flow of the rinsing medium. A vortex separator for carrying out the method according to any one of claims 1 to 8, comprising two or more parallel vortex spaces delimited by walls (1; 39) which are connected in pairs between the vortex spaces by means of an opening (40) in the wall, that the vortex spaces are partially nested, the separable medium supply channel (12) and the separated component discharge channels (14, 70; 13), characterized in that the rinsing medium supply channel (80) opens at the edge of the opening (40) between the vortex spaces at the adjacent vortex spaces. Vortex separator according to Claim 9, characterized in that the rinsing medium supply channel (80) is slit-like. Vortex separator according to Claim 9 or 10, characterized in that the rinsing medium supply pipe (81) simultaneously acts as a flow divider (39) between the vortices (2). 11 Claims 69766 Vortex separator according to Claim 11, characterized in that the rinsing medium supply pipe (81) is formed by a hollow flow distributor (39) between the vortices, which has a longitudinal gap at the opening (40) between the vortex spaces. Vortex separator according to Claim 11 or 12, characterized in that in the series separator the rinsing medium supply pipe (81) and the rinsing medium supply jet opening therefrom together form a flow divider between the vortices. 69766 Vortex separator according to one of Claims 9 to 11, characterized in that the rinsing medium is arranged to be fed from nozzle tubes. Vortex separator according to one of Claims 9 to 14, characterized in that the rinsing medium supply channel (80) or the nozzles are directed at an angle (α) to the interface (90) between the vortex spaces. Vortex separator according to one of Claims 9 to 15, characterized in that the direction and / or the size of the flow opening of the rinsing medium supply channel (80) or of the supply nozzles are adjustable. Vortex separator according to one of Claims 9 to 16, characterized in that the supply pipe (81) is provided with means for adjusting the supply pressure of the rinsing medium. Vortex separator according to one of Claims 9 to 17, characterized in that the rinsing medium supply channel (80) is the entire height of the vortex space. Vortex separator according to one of Claims 9 to 18, characterized in that the connection point between the rinsing channel (80) of the rinsing medium and the opening (40) between the vortex spaces is of porous material. Vortex separator according to one of Claims 9 to 19, characterized in that the cross-sectional area of the outflow opening of the rinsing medium supply channel (80) increases towards the vortex chamber cover (47) or the vortex chamber bottom (68). 14 Patent krav 69766