Chemical pump with shear dispersion impeller

Abstract

The chemical pump is of a semi-open type centrifugal pump structure and is composed of a plurality of blades and a disc, the blades are evenly arranged in the circumferential direction and fixed to the disc, the tail edges of the blades extend to the outer side of the disc, and cutting blades are arranged at the ends of the tail edges of the blades and fixed through positioning pins; each group of cutting blades consists of two blades which are parallel to each other up and down; and two cylinders are arranged between the two blades in each group. According to the method, the previous design mode of passive defense of microscopic aggregation is changed, and the design thought that latex microscopic aggregation is actively sheared to be dispersed in time so as to maintain dynamic stability of the latex microscopic aggregation is adopted; a streamline double-layer cutting blade and a double-cylinder structure are integrated, the synergistic effect of large-scale shearing and small-scale vortex street mixing is achieved, and the problem of uneven dispersion of viscous multiphase media is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chemical production equipment, and particularly relates to a chemical pump suitable for viscous multiphase medium. BACKGROUND

[0002] In chemical production, the emulsion polymerization method is a relatively common polymerization method, which is a processing method for dispersing monomers into emulsions for polymerization reaction through the action of emulsifiers. The system comprises four basic components of monomers, initiators, emulsifiers and water, and forms a colloidal emulsion composed of two or more phases of medium through mechanical stirring under different temperature conditions for reaction.

[0003] The colloidal emulsion, also known as latex, is a metastable state of kinetic stability and thermodynamic instability. Although the kinetic stability can ensure the dispersion stability of the system under the condition that the external conditions remain unchanged, the thermodynamic instability determines that the latex will inevitably aggregate, so it is very sensitive to external conditions, which increases the difficulty of transportation. Because the medium has high viscosity and strong sensitivity, the rotor pump is usually used for transportation, which can output stable flow without extrusion and shear to ensure the stability of the system. However, once the state stability is destroyed during the transportation process, the latex will micro-aggregate during the transportation process, and then the medium will be unevenly dispersed and the viscous aggregates will block the flow channel, which seriously affects the transportation efficiency and product quality.

[0004] In addition, the existing chemical pump impeller only has a transportation function and lacks a design of active shear dispersion for viscous aggregates, so it cannot meet the uniform transportation requirements of high-viscosity multiphase medium. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the present application provides a chemical pump with a shear dispersion impeller, which realizes the integration of "transportation + shear dispersion" through structural innovation, and the specific technical scheme is as follows: A chemical pump with a shear dispersion impeller, which adopts a semi-open centrifugal pump structure and is composed of a plurality of blades 1 and a disc 2. The plurality of blades 1 are uniformly arranged in the circumferential direction and fixed on the disc 2, the tail edge of the blade 1 extends to the outside of the disc 2, the tail edge end of the blade 1 is provided with a cutting blade 3, and the cutting blade 3 is fixed by a positioning pin; each group of the cutting blade 3 is composed of two upper and lower parallel blades 3-1, and two cylindrical bodies 3-2 are arranged between each group of two blades 3-1.

[0006] Preferably, the front half of the cutting blade 3 connected with the impeller is semicircular, and the rear half is crescent-shaped.

[0007] Further preferably, the outside streamline curve is consistent with the tail edge curve of the blade 1.

[0008] Preferably, the height of the entire impeller is 110 mm.

[0009] Preferably, the impeller diameter is 300mm.

[0010] Preferably, the maximum width of the blade 3-1 (i.e., the diameter of the semicircle) is 18 mm.

[0011] Preferably, the distance between the two parallel blades 3-1 is 15mm, and the thickness of each blade 3-1 is 3mm; Preferably, the diameter of the two cylinders 3-2 is 5~8mm, the included angle α along the impeller circumference is 30°, and the axial distance is 9~12mm.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: Structural Innovation: This invention changes the previous design approach of passively defending against micro-aggregates. Instead, it adopts a design concept that actively shears the micro-aggregates of latex to disperse them in a timely manner, thereby maintaining their dynamic stability. It integrates a streamlined double-layer cutting blade 3 with a double cylindrical structure to achieve the synergistic effect of "large-scale shearing + small-scale vortex mixing", effectively solving the problem of uneven dispersion of viscous multiphase media. Functional integration: The medium shearing and dispersion are completed simultaneously during the pump delivery process, eliminating the need for additional mixing equipment and reducing system complexity and cost; Efficiency Improvement: The turbulent disturbance of the double Karman vortex street significantly improves the uniformity of medium mixing, ensuring product quality while improving conveying efficiency. Attached Figure Description

[0013] Figure 1 This is a top view of the shearing and dispersing impeller of the chemical pump of the present invention; Figure 2 This is a three-dimensional structural schematic diagram of the shearing and dispersing impeller of the chemical pump of the present invention; Figure 3 This is a side view of the shearing and dispersing impeller of the chemical pump of the present invention; Figure 4 This is a schematic diagram showing the circumferential angle of the cylinder of the shearing and dispersing impeller of the chemical pump of the present invention. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0015] Example 1: like Figures 1-3The impeller shown in this embodiment is a shear impeller of a chemical pump. This impeller adopts a semi-open centrifugal pump structure. The overall height of the impeller is 110mm, consisting of four blades 1 and one disc 2. The four blades 1 are evenly arranged circumferentially and fixed on the disc 2. The diameter of the entire impeller is 300mm. The trailing edge of the blades 1 extends to the outside of the disc 2, and a cutting blade 3 is provided at the end of the trailing edge of the blades 1, fixed by a positioning pin. The inner and outer sides of the cutting blade 3 are both streamlined curves, intersecting at the tail and closed by rounded corners. The outer streamlined curve is consistent with the trailing edge curve of the blades 1. In this embodiment, the front half of the cutting blade 3 connecting to the impeller is semi-circular, and the rear half is crescent-shaped. The maximum width of the blade 3-1 (i.e., the diameter of the semi-circle) is 18mm. Each set of cutting blades 3 consists of two vertically parallel blades 3-1, with a spacing of 15 mm between them and a thickness of 3 mm for each blade 3-1. Two cylinders 3-2 are provided between the two blades 3-1 in each set. The diameter of the two cylinders 3-2 is 6 mm, the included angle α along the impeller circumference is 30°, and the axial spacing is 10 mm. The matching of these parameters is more conducive to the formation of the Karman vortex street.

[0016] In this embodiment, the shear impeller of the chemical pump is a cantilever pump structure. A bearing is provided behind the disc 2 to connect with the motor shaft. In addition to this embodiment, the blade 1 structure proposed in this invention can be configured as a multi-stage pump structure, a double-suction pump structure, etc.

[0017] When the impeller rotates at high speed, the streamlined cutting blade 3 exerts a strong shearing effect on the fluid in the impeller channel and volute region, which can break down and disperse large-scale viscous aggregates. At the same time, the double cylinders form a double Karman vortex street under the relative motion of the fluid, which generates secondary shearing on small-scale viscous aggregates and enhances the mixing of the medium through periodic turbulent disturbance, ultimately achieving uniform dispersion and transportation of chemical media, improving production efficiency and product quality.

[0018] When this impeller is used for conveying latex media, the rotation speed is 1450 r / min. Tests show that the dispersion uniformity of viscous aggregates in the medium is improved by 40% compared to conventional impellers, and the conveying efficiency remains above 90%, which can meet the high-efficiency homogeneous conveying requirements of chemical production.

Claims

1. A chemical pump with a shearing and dispersing impeller, characterized in that, The chemical pump adopts a semi-open centrifugal pump structure. Its impeller consists of multiple blades (1) and a disc (2). The multiple blades (1) are evenly arranged in the circumference and fixed on the disc (2). The trailing edge of the blades (1) extends to the outside of the disc (2). The trailing edge of the blades (1) is provided with a cutting blade (3), which is fixed by a positioning pin. Each set of the cutting blades (3) consists of two blades (3-1) that are parallel to each other. There are two cylinders (3-2) between the two blades (3-1) in each set.

2. The chemical pump with a shearing and dispersing impeller according to claim 1, characterized in that, The front half of the cutting blade (3) that connects with the impeller is semi-circular, and the rear half is crescent-shaped.

3. The chemical pump with a shearing and dispersing impeller according to claim 2, characterized in that, The streamlined curve on the outer side of the cutting blade (3) is consistent with the trailing edge curve of the blade (1).

4. The chemical pump with a shearing and dispersing impeller according to claim 3, characterized in that, The total height of the impeller is 110mm.

5. The chemical pump with a shearing and dispersing impeller according to claim 4, characterized in that, The impeller has a diameter of 300mm.

6. The chemical pump with a shearing and dispersing impeller according to claim 5, characterized in that, The maximum width of the cutting blade (3), i.e., the diameter of the semicircle, is 18 mm.

7. The chemical pump with a shear-dispersing impeller according to claim 6, characterized in that, The distance between the two parallel blades (3-1) is 15mm, and the thickness of each blade (3-1) is 3mm.

8. The chemical pump with a shear-dispersing impeller according to claim 7, characterized in that, The two cylinders (3-2) have a diameter of 5~8mm, an included angle α of 30° along the impeller circumference, and an axial distance of 9~12mm.

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