Impeller and powder-liquid mixing equipment

Abstract

The present application relates to an impeller and a powder-liquid mixing device. The impeller includes a plurality of blades arranged in sequence around the axial direction of the impeller. Each blade includes a leading edge, a low-pressure surface, a trailing edge, and a high-pressure surface connected in sequence from head to tail to form its circumferential surface. The low-pressure surface is an arc surface convex outward, and the leading edge smoothly connects the low-pressure surface and the high-pressure surface. The thickness of the blade increases first and then decreases from the leading edge to the trailing edge. The chord line of the blade is inclined to the axial direction of the impeller. The technical solution of the present application helps to improve the dispersion effect of powder in liquid and improve the quality of slurry.

Description

Technical Field

[0001] The present application relates to the field of pulping technology, and in particular to an impeller and a powder-liquid mixing device. Background Art

[0002] The pulping process is a process of conveying powder and liquid into a powder-liquid mixing device for mixing and dispersing to obtain a homogeneous slurry. It is widely used in fields such as lithium battery slurry. In some powder-liquid mixing equipment, an impeller is used to pressurize the powder and liquid and mix and disperse the powder and liquid. If the powder is not dispersed well in the liquid, it will easily form large particle agglomerates in the slurry, resulting in poor slurry quality. Therefore, it is necessary to improve the dispersion effect of the impeller. Utility Model Content

[0003] Based on this, the present application provides an impeller and powder mixing equipment, which can improve the powder-liquid mixing effect and improve the slurry quality.

[0004] An impeller comprising:

[0005] A plurality of blades are arranged in sequence and spaced apart in the axial direction around the impeller;

[0006] Each of the blades comprises a leading edge, a low-pressure surface, a trailing edge and a high-pressure surface which are connected in sequence from head to tail to form its blade circumference; the low-pressure surface is an outwardly convex arc surface, and the leading edge smoothly connects the low-pressure surface and the high-pressure surface; the thickness of the blade increases first and then decreases from the leading edge to the trailing edge;

[0007] The chord line of the blade is inclined with respect to the axial direction of the impeller.

[0008] In some embodiments, the projections of the blade sections perpendicular to the extension direction of the blade along the extension direction coincide with each other.

[0009] In some embodiments, the angle between the chord line of the blade and a reference plane perpendicular to the axial direction satisfies: 5°≤θ<90°.

[0010] In some embodiments, the leading edge is in an arc structure that is convex away from the trailing edge, and a radius R1 of the leading edge satisfies: 1 mm ≤ R1 ≤ 10 mm.

[0011] In some embodiments, the trailing edge is in an arc structure that is convex away from the leading edge, and the radius R2 of the trailing edge satisfies: 1mm≤R2≤10mm; or,

[0012] In some embodiments, the trailing edge is pointed.

[0013] In some embodiments, the maximum thickness s of the blade is 3 mm to 20 mm; the maximum thickness s refers to the maximum dimension between the low pressure surface and the high pressure surface in the blade profile section of the blade in a direction perpendicular to the chord line.

[0014] In some embodiments, the chord length a of the blade is 6 to 12 times the maximum thickness s of the blade; the chord length a refers to the length of the chord of the blade.

[0015] In some embodiments, a chord line of each of the blades is located between the high pressure surface and the low pressure surface, and a maximum distance between the chord line and the high pressure surface is smaller than a maximum distance between the chord line and the low pressure surface.

[0016] In some embodiments, the high pressure surface is arranged in a plane.

[0017] In some embodiments, the low pressure surface is a smooth curved surface.

[0018] In some embodiments, the impeller includes a hub with the axial direction of the impeller as the central axis, and the plurality of blades are sequentially spaced and arranged on the outer annular surface of the hub around the axial direction;

[0019] The outer ring surface of the wheel hub is a cylindrical surface.

[0020] A powder-liquid mixing device comprises a mixing chamber and the impeller described in the above embodiment, wherein the impeller is arranged in the mixing chamber.

[0021] In the above-mentioned impeller and powder-liquid mixing equipment, during the rotation of the impeller, the slurry flows from the leading edge of each impeller blade along the high-pressure surface and the low-pressure surface at different flow rates, so that a pressure difference is formed between the high-pressure surface and the low-pressure surface. Under the action of the pressure difference, after the slurry flows out along the high-pressure surface and the low-pressure surface, a turbulent vortex area of ​​the Karman vortex street effect can be formed at the tail of the blade. The formation of the turbulent vortex area can accelerate the dispersion of the powder in the slurry, promote the full mixing of the slurry, and help improve the quality of the slurry. In addition, the blades are subjected to an upward lifting force under the action of the pressure difference and the slurry resistance, which is conducive to increasing the service life of the blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0023] Figure 1 Schematic diagram of the axial side of the impeller of some embodiments.

[0024] Figure 2 for Figure 1 A schematic front view of the impeller is shown.

[0025] Figure 3 Schematic diagram of blade profile cross section of some embodiments.

[0026] Figure 4 for Figure 3 Schematic diagram of the flow field distribution of the blade shown.

[0027] Figure 5 for Figure 3 The force diagram of the blade during operation is shown.

[0028] Figure 6 for Figure 3 Schematic diagram of the blade parameters shown.

[0029] Figure 7 Schematic diagrams of blade sections of blades in other embodiments.

[0030] The reference numerals in the specific implementation manner are as follows:

[0031] 10. Impeller; 11. Blade; 11a. Blade root; 11b. Blade tip; 11c. Blade circumference; c1. Leading edge; c2. Low-pressure surface; c3. Trailing edge; c4. High-pressure surface; x. Chord; 12. Hub; Z. Axial direction; 12a. Shaft hole; 12b. Outer annular surface; M. Blade section; Q. Turbulent vortex area; L. Flow channel. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships, if any, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] In addition, if present, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, if any, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] In the present application, if it appears, unless otherwise clearly specified and limited, a first feature “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature “above”, “above” and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature “below”, “below” and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] It should be noted that, if present, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0038] The embodiment of the present application provides an impeller 10 and a powder-liquid mixing device, which can improve the powder-liquid mixing effect and improve the slurry quality. First, the impeller 10 is introduced.

[0039] According to some embodiments, please refer to Figure 1 , Figure 2 and Figure 3The impeller 10 provided in the embodiment of the present application comprises a plurality of blades 11 arranged in sequence in the axial direction Z of the impeller 10, each blade 11 comprises a leading edge c1, a low pressure surface c2, a trailing edge c3 and a high pressure surface c4 which are connected in sequence from head to tail to form its circumferential surface 11c, the low pressure surface c2 is an arc surface convex outward, the leading edge c1 smoothly connects the low pressure surface c2 and the high pressure surface c4, and the thickness of the blade 11 increases first and then decreases from the leading edge c1 to the trailing edge c3. The chord line x of the blade 11 is arranged to be inclined with respect to the axial direction Z of the impeller 10.

[0040] It can be understood that the impeller 10 includes a hub 12 with its axial direction Z as the central axis, and a plurality of blades 11 are arranged in sequence and spaced around the axial direction Z of the impeller 10 on the hub 12. A flow channel L is formed between adjacent blades 11, which is used to guide the material (powder and / or liquid) to flow from one end of the hub 12 in the axial direction Z to the other end. The drainage direction of the flow channel L between each adjacent blade 11 is the same. The hub 12 can be cylindrical, frustum-conical, etc., and has an outer annular surface 12b arranged around the axial direction Z, and the blades 11 are arranged on the outer annular surface 12b. In addition, an axial hole 12a is arranged at the center of the hub 12, and the axial hole 12a is used to install the hub 12 on the drive shaft, and drive the impeller 10 to rotate through the drive shaft. The axial hole 12a can be a round hole, a square hole, a special-shaped hole, etc.

[0041] It should be noted that the blade 11 includes a blade root end 11a, a blade tip 11b, and a blade circumferential surface 11c connected between the blade root end 11a and the blade tip 11b. The blade root end 11a is connected to the hub 12. In the embodiment of the present application, the extension direction of the blade 11 refers to the direction from the blade root end 11a to the blade tip 11b. The blade circumferential surface 11c of the blade 11 is formed by connecting the leading edge c1, the low-pressure surface c2, the trailing edge c3 and the high-pressure surface c4 in sequence. It is easy to understand that the drainage direction of the flow channel L formed by the blade 11 is from its leading edge c1 along its blade circumferential surface 11c to the trailing edge c3. At this time, the blade shape of the blade 11 is a strip structure with a large front end and a small tail end, which can fit the flow characteristics of the slurry, and the surface has a smooth arc transition, so that the material flows rapidly along its surface.

[0042] The chord line x of the impeller 10 refers to the straight line segment between the leading edge c1 end point and the trailing edge c3 end point on the blade section M perpendicular to the extension direction of the blade 11. The chord line x of the blade 11 is inclined relative to the axial direction Z of the impeller 10, that is, the blade 11 is inclined relative to the axial direction Z of the impeller 10.

[0043] When the impeller 10 rotates, the high-pressure surface c4 hinders the flow of the slurry, so that the flow velocity of the slurry along the high-pressure surface c4 is smaller. Based on the Bernoulli effect (the greater the flow velocity, the smaller the pressure), the pressure on the high-pressure surface c4 of the blade 11 is greater than the pressure on its low-pressure surface c2, and there is a certain pressure difference between the high-pressure surface c4 and the low-pressure surface c2.

[0044] Moreover, since the low-pressure surface c2 is an arc surface convex toward the high-pressure surface c4, and the thickness of the blade 11 increases first and then decreases from the leading edge c1 to the trailing edge c3, the flow rate of the slurry flowing through the low-pressure surface c2 can be greater than the flow rate through the high-pressure surface c4. Based on the Bernoulli effect, the pressure difference between the low-pressure surface c2 and the high-pressure surface c1 can be further increased.

[0045] Thus, during the rotation of the impeller 10, the slurry is divided from the leading edge c1 of each blade 11 of the impeller 10 and flows along the high pressure surface c4 and the low pressure surface c2 at different flow rates, so that a pressure difference is formed between the high pressure surface c4 and the low pressure surface c2. Under the action of the pressure difference, after the slurry flows out along the high pressure surface c4 and the low pressure surface c2, a turbulent vortex area Q (such as the Karman vortex street effect) of the Karman vortex street effect can be formed at the tail of the blade 11. Figure 4 As shown in Figure 2, the formation of the turbulent vortex region Q can accelerate the dispersion of the powder in the slurry, promote the full mixing of the slurry, and help improve the slurry quality. Figure 5 As shown, the blade 11 is subjected to a lifting force (Ftotal) under the combined effect of the pressure difference (forming an upward lifting force Frise) and the slurry resistance (Fresistance), which can increase the service life of the blade 11.

[0046] In some embodiments, the projections of the blade sections M of the blade 11 perpendicular to its extension direction along the extension direction coincide with each other. The blade section M of the blade 11 is a cross section perpendicular to its extension direction. The projections of the blade sections M of the blade 11 along the extension direction of the blade 11 coincide with each other, which firstly indicates that the cross-sectional shapes of the blade sections M of the blade 11 are the same, and secondly indicates that the blade 11 extends from its blade root end 11a to its blade tip end 11b along a straight line. Compared with some blade 11 structures that twist themselves, the processing difficulty of the blade 11 in this embodiment can be greatly reduced, and the processing cost can be reduced.

[0047] In some embodiments, reference Figure 6 , the angle θ between the chord line x of the blade 11 and the reference plane perpendicular to the axial direction Z satisfies: 5°≤θ<90°. In practical applications, the axial direction Z of the impeller 10 is set vertically, and the angle θ can be regarded as the angle between the chord line x of the blade 11 and the horizontal plane. Furthermore, the angle θ can be selected between 15° and 60°, and specifically can be selected as 15°, 20°, 30°, 35°, 42°, 60° and any value between adjacent values. When the angle θ is within the above range, the impeller 10 has a better dispersion effect on the powder, and the slurry is mixed more evenly.

[0048] In some embodiments, reference Figure 3, the leading edge c1 is an arc structure protruding away from the trailing edge c3, and the radius R1 of the leading edge c1 satisfies: 1mm≤R1≤10mm. Specifically, the optional values ​​of radius R1 are 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc. Understandably, the maximum thickness of the blade 11 at the leading edge c1 reaches 2R1. When R1 is within the above range, the thickness at the leading edge c1 is relatively large, and the arc-shaped leading edge c1 can make the front end of the blade 11 evenly compressed, thereby improving the overall strength of the blade 11 and the service life of the blade 11.

[0049] In some embodiments, reference Figure 3 , the trailing edge c3 is an arc structure protruding away from the leading edge c1, and the radius R2 of the trailing edge c3 satisfies: 1mm≤R2≤10mm. Specifically, the optional values ​​of the radius R2 are 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc. Understandably, the maximum thickness of the blade 11 at the trailing edge c3 reaches 2R2. When R2 is within the above range, the thickness at the trailing edge c3 is relatively large, and the arc-shaped trailing edge c3 can make the tail end of the blade 11 evenly compressed, thereby improving the overall strength of the blade 11 and the service life of the blade 11.

[0050] Of course, in another embodiment, the leading edge c1 may be an elliptical structure, and the trailing edge c3 may be a sharp angle (eg Figure 7 shown).

[0051] In some embodiments, reference Figure 6 , the maximum thickness s of the blade 11 is 3mm to 20mm. It can be understood that the maximum thickness s of the blade 11 refers to the maximum dimension between the low-pressure surface c2 and the high-pressure surface c4 in the direction perpendicular to the chord x within the blade section M. In some examples, if the high-pressure surface c4 is a plane, the position corresponding to the maximum thickness s of the blade 11 is the convex point position of the low-pressure surface c2. Specifically, the maximum thickness s of the blade 11 can take values ​​of 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 16mm, etc. When the maximum thickness s of the blade 11 is within the above range, it helps to increase the overall thickness of the blade 11, thereby improving the strength of the blade 11 and the service life of the blade 11.

[0052] In some embodiments, reference Figure 6, the chord length a of the blade 11 is 6 to 12 times the maximum thickness s of the blade 11. It can be understood that the chord length a refers to the length of the chord x of the blade 11. The larger the maximum thickness s of the blade 11, the larger its chord length a. When the two satisfy the above relationship, the overall length of the blade 11 is larger, and under the condition of the same thickness of the blade 11, the low-pressure surface c2 of the blade 11 changes more smoothly from the curved convex point to the trailing edge c3, making it easier to realize the slurry flowing along the low-pressure surface c2 to the trailing edge c3 of the blade 11, so as to form a turbulent vortex area Q at the tail end of the blade 11, thereby improving the mixing effect of the slurry. Specifically, a can be 6 times, 7 times, 8 times, 9 times, 10 times, 11 times and 12 times the maximum thickness s.

[0053] In some embodiments, the chord line x of each blade 11 is located between the high pressure surface c4 and the low pressure surface c2, and the maximum distance between the chord line x and the high pressure surface c4 is smaller than the maximum distance between the chord line x and the low pressure surface c2.

[0054] On the blade section M, the chord line x of the blade 11 is located between the high-pressure surface c4 and the low-pressure surface c2. At this time, the high-pressure surface c4 of the blade 11 can be a plane or a curved surface that is convex to the low-pressure surface c2, so that the slurry on both sides flowing along the high-pressure surface c4 and the low-pressure surface c2 is more likely to form a turbulent vortex area Q at the tail end of the blade 11, and the powder is more fully dispersed.

[0055] The maximum distance between the chord line x and the high pressure surface c4 is the maximum distance between the high pressure surface c4 and the chord line x in the direction perpendicular to the chord line x. Similarly, the maximum distance between the chord line x and the low pressure surface c2 is the maximum distance between the high pressure surface c4 and the chord line x in the direction perpendicular to the chord line x. The low pressure surface c2 is a curved surface, and its maximum distance from the chord line x is the perpendicular distance from its convex point to the chord line x.

[0056] Since the maximum distance between the chord line x and the high-pressure surface c4 is smaller than the maximum distance between the chord line x and the low-pressure surface c2, when the high-pressure surface c4 is a convex curved surface, the curvature near the convex point is also smaller than the curvature of the convex point of the low-pressure surface c2. In this way, the flow rate of the slurry on the high-pressure surface c4 can be further made smaller than the flow rate on the low-pressure surface c2, making it easier to form a pressure difference between the high-pressure surface c4 and the low-pressure surface c2.

[0057] In some embodiments, the high pressure surface c4 is arranged in a plane. When the high pressure surface c4 is a plane, the processing difficulty of the blade 11 can be reduced, and the processing cost can be reduced.

[0058] In some embodiments, the low-pressure surface c2 is a smooth curved surface, which can reduce the flow resistance of the low-pressure surface c2 and make the slurry flow more smoothly.

[0059] In some embodiments, the outer annular surface 12b of the hub 12 is a cylindrical surface. When the outer annular surface 12b is a cylindrical surface, in combination with the Karman vortex effect of the blade 11, the turbulence at the root of the blade 11 can be increased, which is beneficial to the dispersion of the powder.

[0060] In addition, the embodiment of the present application further provides a powder-liquid mixing device, which includes a mixing chamber and the impeller 10 in the above embodiment, and the impeller 10 is arranged in the mixing chamber. The powder-liquid mixing device is used to mix powder and liquid to form slurry. Through the arrangement of the impeller 10 in the above embodiment, the dispersion degree of powder in liquid can be improved, and the mixing quality of slurry can be improved.

[0061] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An impeller (10), characterized in that: include: A plurality of blades (11) arranged in sequence and spaced apart in the axial direction (Z) around the impeller (10); Each blade (11) comprises a leading edge (c1), a low-pressure surface (c2), a trailing edge (c3) and a high-pressure surface (c4) which are connected in sequence from head to tail to form a blade circumferential surface (11c); the low-pressure surface (c2) is an outwardly convex arc surface, and the leading edge (c1) smoothly connects the low-pressure surface (c2) and the high-pressure surface (c4); the thickness of the blade (11) increases first and then decreases from the leading edge (c1) to the trailing edge (c3); The chord line (x) of the blade (11) is arranged to be inclined with respect to the axial direction (Z) of the impeller (10).

2. The impeller (10) according to claim 1, characterized in that: The projections of the blade sections (M) of the blade (11) perpendicular to the extension direction thereof along the extension direction coincide with each other.

3. The impeller (10) according to claim 1, characterized in that: The angle between the chord line (x) of the blade (11) and a reference plane perpendicular to the axial direction (Z) satisfies: 5°≤θ<90°.

4. The impeller (10) according to claim 1, characterized in that: The leading edge (c1) is in an arc structure that is convex away from the trailing edge (c3), and a radius R1 of the leading edge (c1) satisfies: 1mm≤R1≤10mm.

5. The impeller (10) according to claim 1, characterized in that: The trailing edge (c3) is in an arc structure that is convex away from the leading edge (c1), and the radius R2 of the trailing edge (c3) satisfies: 1mm≤R2≤10mm; or, The trailing edge (c3) is in a pointed shape.

6. The impeller (10) according to claim 1, characterized in that The maximum thickness s of the blade (11) is 3 mm to 20 mm; the maximum thickness s refers to the maximum dimension between the low pressure surface (c2) and the high pressure surface (c4) in the blade profile section (M) of the blade (11) in a direction perpendicular to the chord line (x).

7. The impeller (10) according to claim 1, characterized in that The chord length a of the blade (11) is 6 to 12 times the maximum thickness s of the blade (11); the chord length a refers to the length of the chord (x) of the blade (11).

8. The impeller (10) according to claim 1, characterized in that The chord line (x) of each blade (11) is located between the high-pressure surface (c4) and the low-pressure surface (c2), and the maximum distance between the chord line (x) and the high-pressure surface (c4) is smaller than the maximum distance between the chord line (x) and the low-pressure surface (c2).

9. The impeller (10) according to claim 1, characterized in that The high pressure surface (c4) is arranged in a plane.

10. The impeller (10) according to claim 1, characterized in that The low-pressure surface (c2) is a smooth curved surface.

11. The impeller (10) according to claim 1, characterized in that The impeller (10) comprises a hub (12) with the axial direction (Z) of the impeller (10) as the central axis, and the plurality of blades (11) are sequentially arranged at intervals on the outer annular surface (12b) of the hub (12) around the axial direction (Z); The outer annular surface (12b) of the wheel hub (12) is a cylindrical surface.

12. A powder-liquid mixing device, characterized in that: It comprises a mixing chamber and an impeller (10) as claimed in any one of claims 1 to 11, wherein the impeller (10) is arranged in the mixing chamber.

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