Abstract
An impeller assembly for a solid-liquid mixing device, which includes an impeller body, multiple mixing blades which are evenly distributed on the inner side of the impeller body and extended outwards from the shaft of the impeller body, and at least two baffle plates being disposed on the outer side of the impeller body along a radial direction thereof outwards and disposed in the circumferential direction of the impeller body. At least one pair of adjacent two baffle plates satisfies following conditions: curves projected by two opposite surfaces of each of adjacent baffle plates on a cross section of the impeller at any height are smooth curves, and at least one of the curves is not fully included in a circle with the center of the shaft as its center.
Claims
1. An impeller assembly for a solid-liquid mixing device, the impeller assembly comprising an impeller body, a plurality of mixing blades which are evenly distributed being located on an inner side of the impeller body and extended outwards from the shaft of the impeller body, and at least two baffle plates being disposed on an outer side of the impeller body along a radial direction of the impeller body outwards and disposed in a circumferential direction of the impeller body, wherein one of every adjacent two baffle plates is fixedly connected to a cavity of the mixing device, an other of the every adjacent two baffle plates is fixedly connected to the impeller body, and at least one pair of adjacent two baffle plates satisfies following conditions: curves projected by two opposite surfaces of each of adjacent baffle plates on a cross section of the impeller at any height are smooth curves, and at least one of the curves is not fully included in a circle with a center of the shaft as its center.
2. The impeller assembly according to claim 1, wherein the curves corresponding to the two opposite surfaces of the adjacent baffle plates on the cross section at any height are of corrugated structures which fluctuate periodically along the circumferential direction of the impeller body.
3. The impeller assembly according to claim 1, wherein gaps between top ends of the baffle plates and corresponding surfaces of the cavity or the impeller body, and a gap between every adjacent two baffle plates form a bent passage configured for a suspension to flow from the inner side of the impeller body to the outer side of the impeller body.
4. The impeller assembly according to claim 3, wherein sizes of the gaps at the top ends of the baffle plates are 1-10 mm.
5. The impeller assembly according to claim 3, wherein a minimum size of the gap between the every adjacent two baffle plates is 1-5 mm.
6. The impeller assembly according to claim 3, wherein a plurality of through holes or a plurality of through grooves are formed in baffle plates, and the through holes or through grooves, the gaps at the top ends of the baffle plates and the gap between the every adjacent two baffle plates form a bent passage configured for a suspension to flow from the inner side of the impeller body to the outer side of the impeller body.
7. The impeller assembly according to claim 6, wherein a diameter of each of the through holes or a width of each of the through grooves in the baffle plates is 1-5 mm.
8. The impeller assembly according to claim 6, wherein a cross section of at least one of the adjacent baffle plates at a predetermined height thereof is of a structure formed by arranging a plurality of circles, ellipses or other closed smooth curves along the circumferential direction of the impeller body at predetermined intervals.
9. The impeller assembly according to claim 1, further comprising a plurality of discharging blades disposed on an outer side of an outermost one of the baffle plates substantially along the radial direction of the impeller body, and the plurality of discharging blades are fixedly connected with the impeller body and rotate synchronously with the impeller body.
10. A solid-liquid mixing device, comprising the impeller assembly according to claim 1.
11. A solid-liquid mixing device, comprising the impeller assembly according to claim 2.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1a is a schematic diagram of a flow passage of a structure with a stator and a rotor according to the prior art;
[0022] FIG. 1B is a simulation schematic diagram of a flow field of a structure with a stator and a rotor after being simplified according to the prior art;
[0023] FIG. 2a is a schematic diagram of a flow passage of a structure with a stator and a rotor according to the present disclosure;
[0024] FIG. 2b is a simulation schematic diagram of a flow field of a structure with a stator and a rotor after being simplified according to the present disclosure;
[0025] FIG. 3a is a schematic diagram of an impeller assembly according to an embodiment of the present disclosure;
[0026] FIG. 3b is a cross sectional view of the impeller assembly according to the embodiment of the present disclosure;
[0027] FIG. 4a is another schematic diagram of an impeller assembly according to an embodiment of the present disclosure;
[0028] FIG. 4b is another cross sectional view of the impeller assembly according to the embodiment of the present disclosure;
[0029] FIG. 4c is a schematic diagram of a bent flow passage of a mixing device according to an embodiment of the present disclosure;
[0030] FIG. 5a is yet another schematic diagram of an impeller assembly according to an embodiment of the present disclosure;
[0031] FIG. 5b is yet another cross sectional view of the impeller assembly according to the embodiment of the present disclosure;
[0032] FIG. 6a is yet another schematic diagram of an impeller assembly according to an embodiment of the present disclosure;
[0033] FIG. 6b is yet another cross sectional view of the impeller assembly according to the embodiment of the present disclosure;
[0034] FIG. 7a is yet another schematic diagram of an impeller assembly according to an embodiment of the present disclosure; and
[0035] FIG. 7b is yet another cross sectional view of the impeller assembly according to the embodiment of the present disclosure.
LIST OF THE REFERENCE CHARACTERS
[0036] 10 impeller assembly; 101 impeller body; 102 mixing blade; 103 baffle plate; 1031 corrugated structure; 1032 through groove; 1033 flange; 104 discharging blade; and 105 cavity.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0037] In order to make the objectives, principles, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described hereinbelow with reference to the attached figures and embodiments thereof.
[0038] It should be understood that the specific embodiments described herein are used to explain the present disclosure, but the present disclosure may be implemented otherwise than as described herein, and those skilled in the art may make similar generalization without departing from the connotation of the present disclosure. Therefore, the present disclosure is not to be limited by the specific embodiments disclosed below.
[0039] The present disclosure can be applied to various mixing devices equipped with impeller assemblies, and particularly can be applied to the mixing device for solid-liquid mixing. The device of the present disclosure is specifically disposed in a cavity of the mixing device.
[0040] FIG. 3a is a schematic diagram of an impeller assembly 10 provided by the present disclosure. Referring to FIG. 3a, the impeller assembly 10 includes an impeller body 101, multiple mixing blades 102 which are evenly distributed are located on an inner side of the impeller body 101 and extending outwards form a shaft of the impeller body, and inner and outer baffle plates 103 is disposed on an outer side of the impeller body 101 along a radial direction of the impeller body outwards and disposed in a circumferential direction of the impeller body. The inner baffle plate of the two baffle plates 103 is configured to be fixedly connected to a cavity 105 of the mixing device, and inner and outer surfaces of the inner baffle plate are both provided with corrugated structures 1031 which fluctuate periodically along the circumferential direction of the inner baffle plate. The outer baffle plate is fixedly connected to the impeller body 101, and an inner surface of the outer baffle plate is provided with a corrugated structure 1031 which fluctuate periodically along the circumferential direction of the outer baffle plate. It should be understood that for the same baffle plate 103, a side of the baffle plate 103 which is close to the impeller body 101 is the inner surface, and a side of the baffle plate 103 which is away from the impeller body 101 is the outer surface. When the outer baffle plate rotates synchronously along with the impeller body 101, the inner baffle plate and the outer baffle plate move relatively, and curves corresponding to two opposite surfaces of each of the inner and outer baffle plates on a cross section at any height (i.e., a whole height) are continuous corrugated curves. As shown in a simulation schematic diagram of a flow field in FIG. 2b, the corrugated surfaces on each baffle plate 103 guide the suspension between the baffle plates 103 to continuously change the speed direction of the suspension when the suspension flows in the gap defined by the baffle plate. However, a relatively uniform velocity gradient is still maintained. So, under the relative movement of the inner and outer baffle plates, on one hand, uniform strong shear force is generated for the suspension in the flow passage, the suspension is repeatedly sheared, rubbed and extruded, the size of the gap defined between the opposite surfaces of the corrugated structures 1031 is continuously and uniformly changed, namely continuously decreased, continuously increased and then continuously decreased periodically changed. In this way, the average gap between the baffle plates 103 is effectively increases, so that the volume of the dispersion area is increased, vortexes and “dead zones” do not exist, the retention time of the suspension in the flow passage is prolonged, and the dispersion effect is more sufficient. On the other hand, a flow passage with continuously changing width is formed in the corrugated fluctuant surface, so that the speed of the suspension is continuously changed when the suspension flows in the flow passage, which makes the static pressure of the fluid change continuously. When the static pressure is instantly reduced to be low enough, cavitation is caused, multiple microbubbles are generated, and strong impact is caused to particle agglomerates in the suspension, so that the dispersion effect is improved.
[0041] It should be understood that in the embodiment of FIG. 3a and FIG. 3b, the inner baffle plate can also be fixedly connected with the impeller body 101, that is, only one of the inner and outer baffle plates is required to be fixed with the impeller body 101, so that one of the baffle plates is kept movable, and the other is kept static, which is in the protection scope of the present disclosure.
[0042] Optionally, in order to ensure that the suspension is subjected to high shear strength in the flow passage formed by the gaps, a minimum size of the gap between the adjacent inner and outer baffle plates is 1-5 mm.
[0043] Furthermore, optionally, in order to discharge the suspension after passing through the multiple baffle plates 103, the impeller assembly further includes multiple discharging blades 104 disposed on an outer side of the outermost one of the baffle plates substantially along the radial direction of the impeller body 101. The discharging blades 104 are fixedly connected with the impeller body 101 and rotate synchronously along with the impeller body 101. The mixing blades 102 on the impeller body 101 may extend horizontally a predetermined distance on a lower portion of the impeller body 101, as shown in FIG. 3a and FIG. 3b. The discharging blades 104 are integrated with portions of the mixing blades 102 which extend horizontally on the lower portion of the impeller body 101. With the fixed connection design, the suspension can be well stirred, guided and accelerated, and the suspension can be thrown out at a higher speed. The design that mixing blades 102 are integrated with the discharging blades 104 can simplify the overall construction of the impeller assembly 10.
[0044] It should be noted that the continuous corrugated curves shown in FIG. 3a and FIG. 3b are only of schematic illustration and should not limit the present disclosure, and that the design that curves corresponding to the two opposite surfaces of any pair baffle plates at any height are smooth curves is within the protection scope of the present disclosure.
[0045] FIG. 4a is a schematic diagram of an impeller assembly 10 provided by the embodiment of the present disclosure. Referring to FIG. 4a, the difference of the impeller assembly 10 from the impeller assembly shown in FIG. 3a is that the impeller body 101 can be truncated cone-shaped, so that the mixing of powder and liquid can be performed at an upper portion of the truncated cone-shaped body. The suspension formed by the powder and the liquid is driven by the mixing blades 102 to be continuously accelerated in the downward flowing process and finally reaches a dispersion area to be subjected to strong shear dispersion, so that wetting and dispersion of powder are facilitated. The gap shown in FIG. 4b is consistent with the gap in the embodiment shown in FIG. 3b.
[0046] Referring to a relative position of the impeller body 101 in the mixing device in FIG. 4c, gaps are between top ends of the baffle plates 103 and the corresponding surfaces of the cavity 105 or the impeller body 101, and the gaps at the top ends of the baffle plates 103 and a gap between the adjacent baffle plate 103 jointly form a bent passage configured for a suspension to flow from the inner side of the impeller body 101 to the outer side of the impeller body 101. The suspension is subjected to a strong shear effect when flowing in the bent passage. After passing through the bent flow passage, the suspension reaches a space defined by the outer baffle plate and the cavity, and is discharged under the action of the discharging blades 104.
[0047] Optionally, in order to ensure that the suspension can smoothly pass through the multiple baffle plates 103, the sizes of the gaps between the top ends of the baffle plates 103 and the corresponding surface of the cavity 105 or the impeller body 101 are 1-10 mm.
[0048] In other embodiments, multiple through holes or through grooves 1032 are formed in the surfaces of each of the inner and outer baffle plates. The through holes or through grooves 1032, the gaps between top ends of the baffle plates 103 and corresponding surfaces of the cavity 105 or the impeller body 101 and the gaps between the adjacent baffle plates 103 form a bent passage configured for a suspension to flow from the inner side of the impeller body 101 to the outer side of the impeller body 101. The larger the diameters of the through holes 1032 or the widths of the through grooves 1032, the easier the suspension passes through the multiple baffle plates, and the less the average retention time in the curved passage, thereby resulting in reduction of the dispersion effect. So, preferably, the diameter of each of the through holes 1032 or the width of each of the through grooves 1032 is 1-5 mm in order to achieve the dispersion effect while increasing the flow rate of the suspension.
[0049] FIG. 5a is another schematic diagram of the impeller assembly 10 provided by the present disclosure. Inner and outer baffle plates 103 are disposed on the outer side of the impeller body 101 along the radial direction of the impeller body 101 outwards and disposed in the circumferential direction of the impeller body 101. An inner surface of the outer baffle plate is provided with a corrugated structure 1031 which fluctuate periodically along the circumferential direction of the outer baffle plate. The outer baffle plate is fixedly connected with the impeller body 101. Referring to FIG. 5a, the heights of the through grooves 1032 in the surface of the inner baffle plate are close to the height of the outer baffle plate, and the inner baffle plate is disposed so that the cross sections of the inner baffle plate at most heights thereof are discontinuous curves formed by arranging circles at predetermined intervals. In this way, the corresponding curve on the cross section of the surface of the inner baffle plate is a discontinuous smooth curve. The baffle structure in the present embodiment can be understood to be a comb-shaped structure formed by arranging multiple identical cylinders at predetermined intervals, and the interval between cylinders of the comb-shaped structure is 1-5 mm. It should be understood that a surface of the comb-shaped structure is smooth, so that the speed loss is small when the suspension passes through the structure. The flow passage of the suspension is increased through the arrangement, so that the suspension passes through the inner baffle plate more smoothly, and the flow rate is improved. And the structure can guide the fluid to change the speed direction thereof evenly without forming vortexes or “dead zones”, and a good dispersion effect can still be maintained. It should be noted that an upper end of the inner baffle plate is a flange 1033, which is slightly higher than the outer baffle plate and is fixedly connected to the cavity 105 of the mixing device. Optionally, when the longitudinal heights of the through grooves 1032 are close to or even reach the heights of the whole baffle plates 103, the cross sections of the baffle plates 103 at most height thereof can be of comb-shaped structures formed by arranging multiple cylinders in the shape defined by ellipses or other closed smooth curves at predetermined intervals. The typical comb-shaped structures formed by an elliptic cylinder, a cone and the like are within the protection range of the present disclosure, as long as the smooth surfaces of the cylinders are guaranteed. Of course, the comb-shaped structure of the inner baffle plate can be fixedly connected with the impeller body 101, the outer baffle plate is fixedly connected with the cavity, and the inner baffle plate can be fixedly connected without the flange 1033.
[0050] It should be noted that the embodiment shown in FIG. 5a and FIG. 5b is not limited to the fact that the inner baffle plate must be the comb-shaped structure. The inner and outer baffle plates are only described with respect to the impeller body. Alternative embodiments may be provided in which the surface of the inner baffle plate is of a corrugated structure 1031, and the surface of the outer baffle surface is of a comb-shaped structure.
[0051] Besides the impeller assembly of the two baffle plates described above, in other embodiments, in the impeller assembly 10 provided in the present disclosure, more baffle plates are sequentially arranged in sequence on the outer side of the impeller body 101 along the radial direction of the impeller body 101 outwards and arranged in the circumferential direction of the impeller body 101. Referring to FIG. 6a, inner, middle and outer baffle plates are sequentially arranged on the outer side of the impeller body 101 along the radial direction of the impeller body 101 outwards and arranged in the circumferential direction of the impeller body 101. Where, the inner baffle plate and the outer baffle plate are fixedly connected with the cavity 105 of the mixing device and have smooth surfaces. The inner surface and the outer surface of the middle baffle plate are both provided with corrugated structures 1031 periodically fluctuating along the circumferential direction of the middle baffle plate. And the middle baffle plate is fixedly connected with the impeller body 101 and rotates synchronously with the impeller body 101. Gaps defined between the middle baffle plate and the inner baffle plate and between the middle baffle plate and the outer baffle plate are as shown in FIG. 6b. Obviously, the gap between the surface of the corrugated structure 1031 and the smooth surface is continuously and uniformly changed, so that the minimum gap can be kept to be small to maintain high shear strength. Gaps are formed between the inner surface of the middle baffle plate and the inner baffle plate and between the outer surface of the middle baffle plate and the outer baffle plate, so that the volume of the dispersion area between the baffle plates 103 is remarkably increased to ensure enough retention time, and a good dispersion effect is obtained. Preferably, the size of the minimum gap is 1-5 mm. When the gap between the two adjacent baffle plates 103 becomes smaller smoothly, the speed of the suspension in the flow passage is continuously changed, and the static pressure is continuously changed. When the static pressure is instantly reduced to be low enough, cavitation is caused, multiple microbubbles are generated, and strong impact is caused to particle agglomerates in the suspension, so that the dispersion effect is improved. It should be understood that when both the outer surface of the inner baffle plate and the inner surface of the outer baffle plate are provided with or partially provided with corrugated structures 1031, the effect described above is still achieved.
[0052] FIG. 7a is a schematic diagram of an impeller assembly 10 provided by an embodiment of the present disclosure. Referring to FIG. 7a, the difference from the embodiment as shown in FIG. 6a is that the middle baffle plate is the same as the inner baffle plate in the embodiment as shown in FIG. 5a and FIG. 5b. The inner and outer baffle plates are fixedly connected to the cavity 105 of the mixing device to remain stationary, and the middle baffle plate is fixedly connected to the impeller body and rotates synchronously with the impeller body, so that flow passages of the suspension is increased. FIG. 7b shows a flow passage of the suspension formed by the gaps among the three baffle plates in the embodiment, so that the gap between every two adjacent baffle plates is uniformly and continuously changed, the minimum gap can be kept minimum to maintain high shear strength, and the volume of the dispersion area can be significantly increased to ensure enough residence time, thereby obtaining a good dispersion effect. Moreover, the continuously changed width of the flow passage can also cause cavitation as well, multiple microbubbles are generated, and strong impact is caused to particle agglomerates in the suspension, so that the dispersion effect is improved.
[0053] The foregoing descriptions are merely exemplary embodiments of the present disclosure, but are not intended to limit the present disclosure. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure shall fall within the protection scope of the present disclosure.
