FI64293B - FOERFARANDE OCH ANORDNING FOER SEPARERING AV ETT MEDIUM I COMPONENT MED OLIKA PARTIKELMASSOR MED HJAELP AV EN FOERAENDERLIG VIRVEL - Google Patents

Description

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A method and apparatus for separating a medium from components having different particle masses by means of a variable vortex. - Förfarande och anordning för separering av ett medium i komplenter med olika partikelmassor med 5 hjälp av en föränderlig virvel.

The present invention relates to a method and apparatus for separating a medium 10 into components of different particle masses by centrifugal force in free vortex separation devices, e.g. cyclones, so that higher mass particles become enriched in

The term "medium" as used herein is intended to include powdered and fibrous solids, flowing liquids, liquid droplets, gases, and various mixtures thereof. Accordingly, the term "particle" is intended to include solid particles, liquid droplets, liquid molecules, and gas molecules. The term "separation space" is intended to include various vortex chambers as well as other separation spaces in which centrifugal force separates the fluid in motion. The term "helical flow tube" means a flow tube in which particles travel along a helical or near-helical path.

A large number of vortex separators of various shapes are already known, in which the separation space is formed by cylindrical or conical parts. Cyclone separators are discussed, for example, in K. Rietema: "Cyclones in Industry". In known vortex separators, the trajectory of the particles to be separated has been sought to be as homogeneous as possible in the separation space. In general, the shape of the vortex chamber in axial section is rectilinear. Various helical troughs or protrusions have sometimes been made in the vortex chambers to remove or feed the particles. Finnish Patent No. 43,587 provides an example of this. Many designs have also been used to direct particles from the feed section to the vortex chamber. Even in these cases, the vortex chamber 5 itself has a flat shape in the axial direction. The vortex is circular.

A disadvantage of known vortex separators is their poor separation efficiency. In particular, this applies to the removal of fine dust from the gas and to the separation of gases from gas mixtures when it is difficult for particles of different masses to cross each other. As the particles cross in the separation directions, they collide with each other.

The object of the present invention is to improve the separation efficiency of the vortex separators and to obtain a better result by allowing the vortex of the particles to be separated in the separation space to periodically expand alternately in the axial direction and alternately in the radial direction and simultaneously shrink in one of said directions.

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

The invention is illustrated by the following figures.

Figure 1 shows an axial section of a cyclone according to the invention.

Fig. 2 shows in principle the deformation of the particulate mass to be separated in the cyclone according to Fig. 1 at different stages of the rotational movement.

Figure 3 shows a section along the line III-III in Figure 1.

Figure 4 shows a side view of the cyclone of Figure 1 in a smaller size.

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Figure 5 shows an alternative axial section in a cyclone according to the invention.

Figure 6 shows a third alternative axial section in a cyclone according to the invention.

Figure 7 shows a fourth alternative axial section in a cyclone according to the invention.

Figure 8 shows an axial section of a cyclone according to the invention along the line VIII-VIII in Figure 10.

Fig. 10 shows a section along the line X-X in Figs. 15 and 9.

Figure 11 shows a side view of a pair of cyclones according to the invention, in which the vortex chambers are connected to each other.

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Figure 12 shows a side view of another pair of cyclones according to the invention, in which the vortex chambers are connected to each other.

Figure 13 shows an axial section of a cyclone according to the invention, the vortex chamber of which rotates about a center.

Fig. 14 shows a second axial section of the cyclone of Fig. 13 along the line XIV-XIV in Fig. 15.

Figure 15 shows a section along the line XV-XV in Figures 13 and 14.

Figure 16 shows a side view of a helical flow tube according to the invention.

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Fig. 17 shows a section along the line XVII-XVII in Fig. 16.

Fig. 18 shows a section along the line XVIII-XVIII in Figures 17 and 19.

Fig. 19 shows an alternative section along the line XVII-XVII in Fig. 16.

Figure 20 shows an axial section of a helical flow tube according to the invention made to rotate about a hub.

Fig. 21 shows a section along the line XXI-XXI in Fig. 20.

The main content of the invention is to cause the separable particle mass to periodically deform in the radial and axial directions during the rotational movement. In this case, a certain batch of particulate mass 20 is intervened into a smaller space in the axial direction by a sauna when it is allowed to expand in the radial direction and intervened into a smaller space in the radial direction while being allowed to expand in the axial direction. If the changes in the different directions are considered equal, the pressure of the particulate mass does not change substantially.

The shaping of the separable particulate mass into different shapes causes the particles to be repeatedly displaced relative to each other. The transition takes place alternately radially and alternately axially. The displacements of the particles take place in the vortex by volume elements, ie even in the smallest volume units. The magnitude of the particle shifts depends on the magnitude of the deformations.

When a volume of particles is compressed to a smaller size axially and the pulp is allowed to expand radially, the particles of different masses behave differently, while at the same time the centrifugal force acts. Outwardly from the center, particles with a higher mass tend to be the strongest due to the higher centrifugal force, while particles with a smaller mass are on the side of the center more often on average.

Similarly, when a volume of particles is compressed to a smaller size in the radial direction and allowed to expand axially, particles with a higher mass tend to remain on the outer circumferential side and particles with a smaller mass protrude more towards the center.

The transfer of the particles radially past each other in the radial direction is facilitated by the fact that the particles move abundantly also in the axial direction. At the same time, in axial motion, particles of different masses move radially in the desired directions. Lighter particles remain on the center side if trapped, and heavy particles on the outer circumference side if trapped.

By repeating the above-mentioned deformations at short intervals many times, the separation power can be increased to a high level.

In the process according to the invention, the particles to be separated are at the same time subjected to a radial oscillating motion. In this case, the inertial forces generated by the wave motion also contribute to the separation for their part.

30 In addition to the phenomena mentioned above, there is a normal centrifugal separation.

The dimensions and shapes of the devices according to the invention are determined on a case-by-case basis and can be determined experimentally or by theoretical calculations.

The following figures show by way of example some embodiments of the invention and illustrate 6 64293 embodiments of the invention. In reality, a large number of different embodiments can be found for the invention.

The names of the parts shown in the figures are 5 1. the surface delimiting the separation space on the outer circumferential side 2. the general diagonal path of the particles to be separated, i.e. the separating vortex 10. the separation space where the particles of different masses separate in the vortex, i.e. the vortex chamber 10 come to the separation space 13. axial outlet pipe for low mass particles after separation 15 14. axial outlet pipe for high mass particles after separation 18. tangential outlet pipe for high mass particles after separation 19. tangential outlet pipe for low mass particles 20. after separation the cross-sectional area of the particulate mass in the axial direction 35. the cross-sectional area of the particulate mass 25 corresponding to the number 34 in the second part of the duct chamber 36. the location of the wall of the dieshell chamber if the chamber were shaped cylindrical 43rd axial feed tube for separable particles 49. center of the separation space i.e. center of the vortex 30 62. groove in the direction of travel of the vortex 63. ridge in the direction of movement of the vortex 490. center of rotation of the separator

Figures 1 to 4 illustrate the operation of the invention. Figure 1 is an axial sectional view of a vortex chamber 10 of a cyclone according to the invention which is rectilinear at one edge and undulating at the other edge so as to form grooves 62 in the direction of movement 7 between is done evenly and gently. Figure 1 shows the position of the wall of the vortex chamber 10 with the dashed line 36 if the chamber were normally cylindrical. In this example, the cylindrical surface 36 would run from the center of the wavy portion so that the grooves 62 and ridges 63 are equally deep and high on different sides thereof. Fig. 2 shows some parts 34, 35 of the rotating particulate mass shown in diagonal line in Fig. 1 in larger size. The particle mass cutting surfaces 34, 35 shown in Figs. 1 and 2 show the shape of essentially the same particulate mass on different sides of the vortex chamber 10. The areas of the parts 34, 35 are 15 equal. Part 34 is flatter in the radial direction than part 35. Again, part 34 is on average longer in the axial direction than part 35. Figure 3 shows that the depth of the grooves 62 changes evenly as it moves along the circumference of the vortex chamber 10. Likewise, the height of the ridges 63 changes steadily.

In Fig. 1, the surface 1 delimiting the vortex chamber 10 on the outer circumferential side is grooved. Correspondingly, the surface 11 defining the separation space 10 on the inner circumferential side 10 can also be grooved. need not be located symmetrically with respect to the imaginary cylinder surface 36. The grooves 62 and ridges 63 may also be completely on the other side of the imaginary cylinder surface 36. Figure 4 shows a side view of the cyclone of Figures 1-3.

Figure 5 shows a cyclone with grooves 62 and ridges 63 55 with sharp edges. The shapes of the grooves 62 and the ridges 63 can be selected in a wide variety of ways.

Fig. 6 shows a case in which the ridges 63 always extend to the surface 11 delimiting the separation space 10 on the inner circumferential side at its highest point. Thus, the grooves 62 form partially tubular channels in the direction of travel of the vortex 2. The movement of the separable particles in the axial direction 5 takes place mainly at the smooth surface 1.

In Fig. 7, the flat surface 1 of the vortex chamber 10 changes at different points as the vortex 2 advances in the axial direction.

In the cyclone shown in Figures 8-10, the depth of the grooves 62 and the height of the ridges 63 change twice from one extreme value to another during one vortex revolution. Vortex separators can also be formed in which the corresponding changes occur 3, 4, 5, 6, etc. times. Sometimes a flat wall surface 1 is not necessarily required. In order to obtain the result according to the invention, it is sufficient that the depth of the grooves 62 changes.

In the guarantees shown in Figures 11 and 12, the vortex chambers 10 of the two cyclones 20 are brought into contact with each other so that the vortices 2 contact each other laterally at the deepest points of the grooves 62. This eliminates the abrasion resistance of the bottom wall of the groove 62, which facilitates the transport of separable particles from the bottom of the groove forward with the vortex 25 of the groove.

Figures 13 to 15 show an embodiment according to the invention, in which the vortex chamber 10 is made to rotate in the direction of movement of the vortex 2. This reduces the speed difference between the wall 1 of the vortex chamber 30 and the vortex 2 and the resulting turbulence. The absolute velocity of the vortex 2 is higher than the absolute velocity of the chamber wall 1, 62, 63. In the example of Figure 15, the bottoms of the grooves 62 and the ridges of the ridges 63 are elliptical.

Figures 16 to 19 show a helical flow tube according to the invention, the cross-section of which is alternately wider in the axial direction and alternately wider in the diagonal direction, forcing the flow vortex 2 to corresponding deformations. The tubes can be, for example, circular or elliptical in the axial direction.

Other forms are also possible. In the example of Figures 16 to 19, the cross-section of the pipe is rectangular, but other-shaped cross-sections of the pipe are also possible.

In the case shown in Figures 20 and 21, the helical flow tube is caused to rotate about a hub 490 in the flow direction of the wheel 10. This reduces the speed difference between the wall 1, 20 and the vortex 2 and the consequent abrasion resistance. The flow tube can be cast into some suitable mass to increase strength and balance.

Claims (10)

1. A method for separating a medium into components of different particle masses using the centrifugal force of devices operating in a free vortex flow, e.g. in cyclones such that the larger particles are enriched during the rotational movement in the outer peripheral portion of the separation space (10) and the smaller particles are enriched in the part of the separation space (10) which is closer to the center (49), , that the swirl (2) of the separable particles may periodically expand in the separation space (10), alternately in axial direction and alternately in radial direction, and at the same time shrink in one of said directions. Apparatus for realizing the method according to claim 1, characterized in that the wall of the separator space (10) of the vortex separator (10) is grooved in the direction of movement of the vortex (2) in the direction of movement of the vortex (2) and varies in depth or width in the different parts. of the perimeter of the separation space (10). 3. A vortex separator according to claim 2, characterized in that the depth of the groove flames (62) decreases to zero at any point of the circumference of the separating space (10). 4. A vortex separator according to claim 3, characterized in that the grooves (62) transmit into chambers (63) at some point of the circumference of the separating space (10). 5. A vortex separator according to any one of claims 2-4, characterized in that the depth of the grooves (62) is changed several times from one limit value to another along the circumference of the separation space (10).