HU211421B - Method and apparatus for mixing at least two materials, mainly fluids - Google Patents

Abstract

Two or more liq. components are spun and directed onto a stationary grid of radial blades. The liquids are cut, divided and form vortices which promote mixing. The process is repeated several times by recycling. - The equipment comprises a driver carrying an energy transmitting wheel, in the form of a pump impeller, on its shaft. A hydrodynamic grid with stationary blades is located opposite the wheel. The grid is contained in a housing which extends over the wheel and is attached to the drive unit. The housing is provided with one or more end suction connections and a top discharge connection located in the plane of the impeller.

Description

the rod is held in a spiral forced flow, in particular by slicing the material blocks, and in particular by flow into stationary and rotary or rotary and stationary paths, to create material separations and eddies. Further, according to the invention, the rotor (7) is provided with an annular groove (9) on the front face (17) of the mixing chamber (15). This is divided by the blades (10) of the mixing shear element into channels at least approximately radial. In the housing part defining the mixing space (15) on the opposite side of the rotor (7), another annular groove (12) is formed, which is divided into at least approximately radial channels (14) by blades (13) which also act as correct mixing elements. The inlet region of the channels of the rotor (7) is located in the outlet area of the channels (14) of the housing (1) and the inlet region of the channels (14) of the rotor (7).

The present invention relates to a process and apparatus for mixing two or more substances, for example two or more liquids.

The mixing of bi- or multi-component fluids meets the continuous technological needs of the food and chemical industry. The general principle of mixing is to move the base fluid to such an extent that there is maximum miscibility of one or more components to be mixed.

For example, DEPS 2 655 901 discloses a blending process which has been proposed to create a fuel-water emulsion for a better combustion of the fuel blend. In this mixing mode, fuel and water are forced out of the inlet section by centrifugal force outwardly in radial passages and then rammed over a cylindrical wall section. The fluid flow is subjected to shear in the gap between the outer casing of the rotor and the housing wall. Finally, the mixture is introduced into a turbulent flow along a portion of the circumference of the rotor, and finally the emulsion is led directly to the outlet formed at the outlet.

In order to carry out the above process, the cited document proposes an apparatus having essentially the same design as the mixing machines of DEOS 3 342 304 and US 4 175 873. Their common feature is that they operate on the principle of a centrifugal pump. In this type of mixing machine, the inlet in the rotating impeller is coaxial with the axis for the materials to be mixed, which pass in a single radial flow through the rotating impeller and enter the collecting space from which the mixed medium can be drained.

This near radial centrifugal fluid flow is interrupted, for example, by interlocking toothed gratings (see DE 3 342 304) and by pins (see US 4 175 873), resulting in turbulence and shear they are intended to achieve sufficient mixing of the components by mechanical impact. The fluid particle entering the impeller leading edge thus moves away from the inlet, i.e., outwardly in a substantially radial flow, while undergoing forced paths in passageways such as channels between diffuser or confusional radial elements (DE 2 655 901). It should be noted, however, that in conventional solutions, the fluid portions only perform a centrifugal flow once, thereby substantially completing the mixing process. Flows of this type are known in the literature as "centrifugal flow".

Practical experience has shown that impact elements such as pins, combs, wreaths, etc., are placed in the radial flow path. they cause fluid particle separations which lead to a substantially uncontrolled mixing process and, under certain pressure conditions, can lead to cavitation flows which damage both the medium and the mixer itself. The efficiency of such a mixing method is hardly possible in the case of possible, that is to say, delicate quality requirements, on the other hand it essentially lacks the necessary material protection and has unclear flow effects.

It is an object of the present invention to overcome the drawbacks outlined above, that is, to provide an improved mixing method which is universally applicable and provides much more efficient and economical mixing than conventional solutions.

The present invention is based on the discovery that the present invention can be accomplished by interrupting the conventional mechanical mixing principle with hydrodynamic mixing as it is more efficient in providing high turbulence and collisions, and also allows the material flow to be reduced to a smaller amount of material. stirring.

Thus, in order to solve the problem, we have started from the method mentioned in the introduction, whereby a flow of material containing the material components entering the mixing space is forced to flow radially outwards using a centrifugal force, whereupon the material stream is sheared and optionally also through a spill. The process of the present invention is that, once entering the annular mixing space, the liquid stream is slit-sheared into relatively small blocks of material, these outlets are rotated outwardly through rotated and preferably completely separated forced paths, and then and then force them

Again, it is recycled to one of the rotated forced paths, and by performing these operations cyclically, the fluid blocks are kept in a spiral forced flow. in the meantime, particularly during passages between stationary and rotary and rotary and stationary paths, the material blocks are sliced and material separations and eddies are formed.

The process according to the invention can be carried out by means of a device having a rotatably mounted rotor in the housing, the housing having a central inlet and a circumferential outlet and a mixing space therebetween which is partially bounded by the rotor and a rotor extending into the mixing space. and the housing is provided with a mixing-shear element that cooperates with them. The essence of the proposed apparatus is that the rotor is provided with an annular groove in the front of the mixing space, which is divided by the blades acting as mixing shear elements into at least approximately radial channels which act as guides for forced flows. In the housing part defining the mixing space on the opposite side of the rotor, another annular groove is formed, which is also divided into channels by the blades, which also serve as a correct mixing shear element. The inlet region of the rotor ducts is located in the outlet area of the housing ducts, and the outlet area of the rotor ducts is located in the inlet area of the housing ducts.

According to a further feature of the present invention, it is expedient to have an embodiment in which the housing is provided with a collection space behind the rotor, which communicates with the outlet.

It is also desirable if the rotor annular groove and the housing annular groove together form a torus-shaped mixing space in which the blades are radially arranged. This simplifies the manufacturing process.

Preferably, the rotor, for example, can be provided with at least one orifice in the vicinity of the center of rotation to allow the already blended mixture to flow from the mixing chamber to the collecting chamber.

The invention will be described in more detail with reference to the accompanying drawings, in which an exemplary embodiment of the apparatus according to the invention is shown. In the drawing :, the

Figure 1 is a partially sectioned view of a drive motor assembly of the device of the present invention; the

Figure 2 is a detail view of the solution of Figure 1 in a relatively larger scale cross-section; the

Figure 3 is a side sectional view taken along line III-III in Figure 2.

Figure 1 illustrates an exemplary embodiment of an apparatus for carrying out the process of the invention for hydrodynamic mixing of liquids. The device has a housing 1 which is secured to the flange 3 of the drive motor 2 by screwing. The drive motor 2 in this case is an electric motor whose speed can be advantageously controlled.

The housing 1 is provided with an inlet 4, which in this case is arranged in the same axis as the shaft 5 of the drive motor 2. The inlet 4 is for continuous addition of a larger amount of the liquids to be mixed.

Inside the housing 6, the rotor 7 is rotatably arranged, the central hub 8 of which is mounted on the shaft 5 of the drive motor 2. The meridian section of the disk-like rotor 7 is in this case provided with a half-toroidal annular groove 9 provided in this case with radial vanes 10 (Figures 2 and 3). The blades 10 are bordered on both sides by radial channels 11 which are slightly widened towards the outer periphery in Figure 3.

In the case opposite the rotor 7, the housing 1 in this case also has a half-toroidal annular groove 12 provided with blades 13 similar to the blades 10 (not shown separately). These vanes 13 are in this case also radial, so that each of the two adjacent vanes 13 defines a radial and outwardly extending channel 14 on either side. The annular groove 9 of the rotor 7 and the annular groove 12 of the housing 1 formed mirror-symmetrically together form a torus-shaped mixing space 15, which will be discussed in more detail below.

In the embodiment shown in FIG. 2, it is particularly evident that an adjustable clearance 19 is provided between the rotor 7 front face perpendicular to the center of rotation 16 and the parallel housing face 18 of the housing 1 through which the mixing space 15 passes. with the inlet 4 of the housing 1 (Fig. 2). The inner space of the housing 1 behind the rotor 7 is formed as a collecting space 20, from which, through the outlet 21, the mixed liquid mixture can be continuously discharged.

The housing 1 is formed by the annular groove 12 with blades 13 as a stationary hydrodynamic lattice, the function of which, however, is discussed in more detail below.

As shown in Figure 1, a fluid-tight bearing 23 is provided between the hub 8 of the rotor 7 and the cover 22 of the housing 1 in this case. Furthermore, in Fig. 1, the housing 1 is provided with additional inlets 24 and 25, which in this case are spaced radially from the central inlet 4. Through the additional inlets 24 and 25, additional liquid components may be added to the mixing chamber 15. (These are omitted in the Figure 2 version).

As shown in Figure 1, the housing 1 is also provided with a shielding unit 26, which may be, for example, a known heat shield fuse and / or a pressure relief device for releasing at the required maximum pressure.

As can be seen in Figure 2, the rotor 7 in this case is provided with a through hole 27 near the hub 8, which connects the mixing space 15 to the collecting space 20 behind the rotor 7. This orifice 27 may also be omitted, since through the above-mentioned spacing 19, the passage from the mixing space 15 to the collection space 20 can be carried out by itself.

In embodiments where the agitator of the present invention is also required to provide a certain transport height for returning the stream of the already mixed liquid mixture continuously discharged through the outlet 21, the rear portion of the rotor 7 is

EN 211 421 B can be provided with a suitable 28 shovels (Fig. 2). The blade 28 also has an additional mixing effect in the collecting space 20, so that the rotor 7 also acts as a pump impeller for the mixed and transported liquid mixture (the back blade is indicated by a thin score line in Figure 1).

1-3. The operation of the apparatus according to Figs.

In view of the fact that the hydrodynamic mixing apparatus according to the invention is in this case a continuous operation, the liquids to be mixed are introduced into the apparatus as a continuous flow through the inlet 4. In the present case, the outer diameter of the rotor 7 was selected to be 400 mm, the radius R of the profile of the semicircular grooves 9 and 12 was selected to be 60 mm and the rotor speed was set to 1500 rpm. THE

In Fig. 2, following the fluid flow path, the leading edge of the rotor 7 is 29, the leading edge 30, the leading edge 12 of the housing 1 is marked 31, and the leading edge 32 is designated 32.

Thus, the fluid column to be mixed enters through the inlet 4 into a disc-shaped passage 33, from where it flows outwardly under the action of the centrifugal force exerted by the rotating rotor 7. At the inlets 29, the blades 10 of the rotating rotor 7 are "sliced", i.e. subdivided into small pieces of liquid, by the fluid stream to be mixed. Each fluid column in the conduit 11 will first conduct a centrifugal flow in the direction indicated by arrows 34 and 35 in FIG. At the outlet edge 30 of the conduit 11, after a short axial flow, the outlet fluid passes into the channel 14 of the annular abutment 12 of the housing 1 facing the blades 13 and in the directions 36 and 37 in FIG. performs a forced flow towards the centerline. At its exit edges 32, said fluid block exits from channel 14 and enters another opposing channel 11 of rotor 7 and continues the centrifugal flow indicated by arrows 34 and 35, as mentioned above. Each fluid column thus flows in a spiral flow in the meridian section through the channels 11 and 14 of the torus-shaped mixing space 15. The axis of this special helical forced flow of fluid blocks is the center of division of the entire toroidal mixing chamber 15.

It is emphasized that since there is a relative rotation between the stationary blade of the housing 1 and the rotated rotor 7 during operation, the liquid end is subjected to multiple shredding, shearing at the leading edges 29 and 31. Thus, the fluid column in the mixing chamber 15 not only carries a single radial flow, as in conventional solutions, but also performs a specific, relatively long, helical forced flow in the mixing chamber 15, thereby providing original hydrodynamic mixing. The fluid column is thus subdivided into small pieces of liquid by the blades 10 and 13, and by repeatedly and repeatedly crushing them, and by turbulent mixing of the fluid elements, through the resulting fluid separation and collisions, we have found experimentally impressive mixing to meet the .

From the mixing space 15 through the gap 19 and through the orifice 27, the already blended mixture enters the collection space 20, from where it is discharged through the outlet 21 to the destination or storage site. In the collecting space 20, the shovel 28 optionally provides post-mixing and, optionally, a delivery conveyor height.

Thus, in the hydrodynamic mixing method according to the invention, the angular momentum of the fluid column fed to the mixing chamber 15 is suddenly increased by the centrifugal flow of sliced liquid blocks along arrows 34 and 35 in the channel 11 of the rotor 7 as working spaces. The outer mantle of 11 channels. The fluid column then enters the stationary channel 14 of the housing 1 with a short axial flow, whereby the centrifugal flow follows the shape of the channel 14 in the direction of arrows 36 and 37, and then re-enters another channel 11 of the rotor 7 as mentioned above. However, it should be emphasized that in the case of transitions, the liquid molecule that passes from the stationary channel 14 is never returned to the same channel 11 of the rotor 7, since the rotor 7 has since turned. Thus, molecules crossing from stationary channels 14 enter into the opposite channel 11 together at the portion of the agitators 15 near the centerline 16. Thus, each material molecule traverses a helical path defined by a toaoid centerline as an axis and, depending on the number of blades and revolutions, passes hundreds of times from the rotor channels 11 to the housing 14, forming newer or newer material molecules. liquid columns.

Thus, the hydrodynamic mixing system of the present invention becomes self-mixing, i.e., it does not require the flow disruption elements conventionally encompassed to achieve a satisfactory mixing effect.

The most important advantage of the present invention is therefore that the homogeneous mixture or mixture can be prepared economically and quickly by means of a relatively simple and reliable apparatus by means of hydrodynamic mixing. Given that the mixing efficiency can be varied within wide limits depending on the particular application, the present invention as a one-step apparatus is capable of much better mixing efficiency than even multi-stage variants of conventional solutions. For example, mixing quality control can be accomplished by proper control of the fluid flow through, the use of additional inlets 24, 25, or the density, shape and rotor speed of the blade.

Finally, it is emphasized that the mixing space 15 formed by the ring grooves 9 and 12 in the housing 1 and the rotor 7 does not necessarily have to be semi-circular, and may also consist of curved and / or polygonal sections, or a combination thereof. The blades 10 and 13 do not necessarily have to be radial, they may be inclined, bent, or even provided with a special surface profile. It is also noted that although in the exemplary embodiment shown in Fig. 4, the annular grooves 9 and 12 are filled to their full depth by the blades 10 and 13, however, they may be round or slab-shaped. Thus, many other embodiments and combinations of the apparatus of the present invention are possible within the scope of the claimed application, but the basic requirement for each of these is the hydrodynamic mixing mode described above. Optionally, the annular groove 12 (and its blades 13) facing the rotor 7 may be formed as another rotor mounted within the housing 1 and may have a rotation speed less than or greater than the rotor 7, i.e. relative rotation therebetween. The present invention can be used with similar advantages for mixing powdered, granular, flowable, paste-like, gaseous materials and liquids.

PATENT CLAIMS.

Claims (5)

PATENT CLAIMS. A process for mixing at least two materials, in particular liquids, by subjecting a material stream receiving material components entering the annular mixing chamber to a radially outward flow by centrifugal force, thereby subjecting the material stream to shear. and optionally bringing it into a turbulent flow and finally discharging the mixture or mixture through an outlet, characterized in that, upon entering the annular mixing space, the liquid stream is slit-sheared into material blocks, preferably completely separated by centrifugal flow, moving the outlets and moving the fluid blocks into stationary forced paths, where they are forced into a centripetal flow, and then the material blocks are returned to one of the rotating paths, and by performing these steps cyclically, and flow into stationary forced paths - we slice up the material blocks, and we get material separations and swirls etre. An apparatus for carrying out the process of claim 1, comprising a rotor-mounted rotor in the housing, the housing having a central inlet and a circumferential outlet, and associated mixing space, partially bounded by the rotor, and the housing is provided with mixing-shear elements extending into the mixing chamber and the housing having mixing-shearing elements cooperating therewith, characterized in that the rotor (7) is provided with an annular groove (9) on the front face (17) of the mixing chamber (15). blades (10) as shear members divide at least approximately into radially positioned passages (11) and further, in the housing portion defining the mixing space (15) opposite the rotor (7), a second annular groove (12) is also provided. blades (13) at least approximately radially positioned the rotor (7) channels (11) in the discharge area of the housing (1) channels (14), and the rotor (7) channels (11) in the discharge area of the housing (1) channels (14) ) in the inflow area. Apparatus according to claim 2, characterized in that a collecting space (20) is formed in the housing (1) behind the rotor (7), which is connected to the outlet (21). Apparatus according to claim 2 or 3, characterized in that the annular groove (9) of the rotor (7) and the annular groove (12) formed in the housing (1) together form a toroidal mixing space (15) and their blades (10 and 13, respectively) are radially arranged. 5. Apparatus according to any one of claims 1 to 3, characterized in that the rotor (7) is preferably provided with at least one orifice (27) in the vicinity of the center of rotation (16) which connects the mixing space (15) to the collecting vessel (20).