阅读说明：本技术 一种离心空化泵 (Centrifugal cavitation pump ) 是由 王勇 张国翔 李刚祥 吴璞 于 2020-06-02 设计创作，主要内容包括：本发明提供了一种离心空化泵,包括螺旋形蜗壳和离心转轮,所述离心转轮包括前盖板、直叶片和后盖板,所述前盖板和后盖板之间设有若干均布的直叶片,相邻所述直叶片的进口之间均布若干节流挡墙,且若干所述节流挡墙位于前盖板和后盖板之间；相邻的所述节流挡墙之间设有间隙。本发明可以有效控制下游的溃灭压力,从而达到既能输送有机污水又能控制溃灭强度的要求；这种离心空化泵能尽可能的减小能量损失,为空泡提供更多的溃灭能量。(The invention provides a centrifugal cavitation pump, which comprises a spiral volute and a centrifugal rotating wheel, wherein the centrifugal rotating wheel comprises a front cover plate, straight blades and a rear cover plate, a plurality of uniformly distributed straight blades are arranged between the front cover plate and the rear cover plate, a plurality of throttling retaining walls are uniformly distributed between inlets of adjacent straight blades, and the throttling retaining walls are positioned between the front cover plate and the rear cover plate; and a gap is formed between the adjacent throttling retaining walls. The invention can effectively control the downstream collapse pressure, thereby meeting the requirements of conveying organic sewage and controlling the collapse strength; the centrifugal cavitation pump can reduce energy loss as much as possible and provide more collapse energy for cavitation bubbles.)

1. A centrifugal cavitation pump comprises a spiral volute (1) and a centrifugal rotating wheel (2), wherein the centrifugal rotating wheel (2) comprises a front cover plate (3), straight blades (5) and a rear cover plate (6), and a plurality of uniformly distributed straight blades (5) are arranged between the front cover plate (3) and the rear cover plate (6), and the centrifugal cavitation pump is characterized in that a plurality of throttling retaining walls (4) are uniformly distributed between inlets of adjacent straight blades (5), and the throttling retaining walls (4) are positioned between the front cover plate (3) and the rear cover plate (6); and a gap is formed between the adjacent throttling retaining walls (4).

2. The centrifugal cavitation pump in accordance with claim 1, characterized in that the throttle retaining wall (4) is an isosceles triangle throttle retaining wall.

3. The centrifugal cavitation pump in accordance with claim 2, characterized in that any isosceles triangle-shaped flow-restricting wall is symmetrical along a radial line of the center of the centrifugal rotor (2).

4. The centrifugal cavitation pump as claimed in claim 2, wherein the isosceles triangular dams are uniformly arranged along the circumferential direction of the centrifugal rotor (2), and the contraction rate η ═ θ of the isosceles triangular dams₂/θ₁0.7 to 0.95, wherein θ₁Is the radian between the centers of two adjacent isosceles triangle throttle retaining walls, theta₂Is formed by two end points of the bottom edge of any isosceles triangle throttling retaining wallIn the arc of a circular arc.

5. The centrifugal cavitation pump of claim 2, characterized in that the isosceles triangle shaped throttle retaining wall near the straight vane (5) is smoothly connected with the straight vane (5); the bone line of the straight blade (5) is a ray passing through the middle point of the centrifugal rotating wheel (2); the straight blades (5) are uniformly distributed along the circumferential direction.

6. Centrifugal cavitation pump according to claim 2, characterized in that the number Z of straight blades (5)₁＝5～12。

7. The centrifugal cavitation pump of claim 2, wherein the number of isosceles triangular dams Z ₂＝nZ₁And n is a positive integer.

Technical Field

The invention relates to the field of sewage treatment, in particular to a centrifugal cavitation pump.

Background

The continuous development of industry and agriculture leads to more and more domestic sewage and industrial sewage to be directly discharged into rivers and lakes, and the eutrophication of water bodies can be caused when the sewage exceeds the upper limit of ecological self-purification capacity. Harmful microorganisms such as algae are easy to grow in the eutrophic water sources, and the existence of the harmful microorganisms can pose great threat to the drinking water health of human beings and the survival of aquatic organisms, so that the sterilization and algae removal work aiming at the eutrophication of the water body is urgent.

The royal health doctor studied cavitation erosion of a stator-rotor type hydrodynamic cavitation generator. The rotor-stator cavitation generator is designed by cutting an impeller of a centrifugal pump, additionally installing a rotor rotating together with the impeller, and arranging a stator near a front cover plate. This results in three forms of cavitation from the relative rotor-stator motion, the cavitation occurring primarily near the rotor-stator interface. However, the inventor does not consider whether the outlet of the cavitation generator can generate enough pressure, and the pressure can smoothly discharge the sewage out of the cavitation generator on one hand, and on the other hand, the increase of the downstream pressure can improve the breaking energy of the cavitation bubbles, thereby achieving the purpose of strengthening the cavitation effect.

The korean scholars hynsoo Kim studied the number of cavitation bubbles and the cavitation collapse intensity of a new cavitation generator. The novel cavitation generator is composed of a shell and a rotating wheel, wherein 32 round holes are formed near the outer diameter of the rotating wheel, grooves with the same number as the round holes are formed in the corresponding positions of the two sides of the rotating wheel, the inlet is formed in one side of the rotating wheel, and liquid enters the other side of the rotating wheel through the round holes. Through the rotary motion of the runner, the sectional area between the round hole and the groove is periodically changed, and then cavitation is generated. The periodic change of the rotor causes the cavitation bubbles to periodically fall off, thereby increasing the collapse frequency of the cavitation bubbles. However, the flow direction of the liquid of the cavitation generator is changed in the circular hole from radial direction to axial direction and then from axial direction to radial direction, so that the flow loss of the liquid is increased, and the dissipated pressure energy can be converted into energy of cavitation bubbles for storage.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the centrifugal cavitation pump which can effectively control the downstream collapse pressure, thereby meeting the requirements of conveying organic sewage and controlling the collapse strength; the centrifugal cavitation pump can reduce energy loss as much as possible and provide more collapse energy for cavitation bubbles.

The present invention achieves the above-described object by the following technical means.

A centrifugal cavitation pump comprises a spiral volute and a centrifugal rotating wheel, wherein the centrifugal rotating wheel comprises a front cover plate, straight blades and a rear cover plate, a plurality of uniformly distributed straight blades are arranged between the front cover plate and the rear cover plate, a plurality of throttling retaining walls are uniformly distributed between inlets of adjacent straight blades, and the throttling retaining walls are positioned between the front cover plate and the rear cover plate; and a gap is formed between the adjacent throttling retaining walls.

Furthermore, the throttling retaining wall is an isosceles triangle throttling retaining wall.

Furthermore, any isosceles triangle throttling retaining wall is symmetrical along the radial line at the center of the centrifugal rotating wheel.

Furthermore, the isosceles triangle-shaped throttling retaining walls are uniformly distributed along the circumferential direction of the centrifugal rotating wheel, and the shrinkage rate eta of the isosceles triangle-shaped throttling retaining walls is equal to theta₂/θ₁0.7 to 0.95, wherein θ ₁Is the radian between the centers of two adjacent isosceles triangle throttle retaining walls, theta₂The radian of the arc where the two end points of the bottom edge of any isosceles triangle throttle retaining wall are located.

Further, the isosceles triangle throttling retaining wall close to the straight blade is smoothly connected with the straight blade; the bone line of the straight blade is a ray passing through the midpoint of the centrifugal runner; the straight blades are uniformly arranged along the circumferential direction.

Further, the number Z of the straight blades₁＝5～12。

Further, the number Z of the isosceles triangle throttle retaining walls₂＝nZ₁And n is a positive integer.

The invention has the beneficial effects that:

1. the centrifugal cavitation pump can control the downstream collapse pressure by changing the number and the length of the short blades and the rotating speed of the centrifugal rotating wheel at the cavitation downstream, thereby meeting the requirements of conveying organic sewage and controlling the collapse strength.

2. According to the centrifugal cavitation pump, the flow channel of the centrifugal cavitation pump is in accordance with the liquid flow rule, liquid is smoothly transited from the axial direction to the radial direction, and certain impact loss can be generated only near the isosceles triangle throttling retaining wall, so that energy loss is reduced as much as possible.

3. The centrifugal cavitation pump simulates the internal flow field of the centrifugal cavitation pump through CFX, and the result shows that: the straight blades can effectively improve the downstream bursting pressure and smoothly convey the organic wastewater; and the pressure drop in the whole flow passage is lower.

Drawings

Fig. 1 is a schematic structural diagram of a centrifugal cavitation pump according to the present invention.

FIG. 2 is an axial cross-sectional view of a centrifugal rotor according to the present invention.

Fig. 3 is a water body assembly diagram of the numerical simulation of the centrifugal cavitation pump according to the present invention.

FIG. 4 is a cloud diagram of the distribution of cavitation bubble volume of the centrifugal cavitation pump according to the present invention.

In the figure:

1-a spiral volute; 2-centrifugal rotating wheel; 3-front cover plate; 4-throttling retaining wall; 5-straight blade; 6-rear cover plate.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

As shown in fig. 1 and 2, the centrifugal cavitation pump of the present invention includes a spiral volute 1 and a centrifugal rotor 2, and the spiral volute 1 and the centrifugal rotor 2 are coaxially assembled. The centrifugal rotating wheel 2 comprises a front cover plate 3, straight blades 5 and a rear cover plate 6, wherein a plurality of uniformly distributed straight blades 5 are arranged between the front cover plate 3 and the rear cover plate 6, a plurality of throttling retaining walls 4 are uniformly distributed between inlets of adjacent straight blades 5, and the throttling retaining walls 4 are positioned between the front cover plate 3 and the rear cover plate 6; and a gap is formed between the adjacent throttling retaining walls 4.

Any isosceles triangle throttling retaining wall is symmetrical along the radial line of the center of the centrifugal runner 2. The isosceles triangle throttling retaining walls are uniformly distributed along the circumferential direction of the centrifugal rotating wheel 2, and the shrinkage rate eta of the isosceles triangle throttling retaining walls is theta ₂/θ₁0.7 to 0.95, wherein θ₁Is the radian between the centers of two adjacent isosceles triangle throttle retaining walls, theta₂For any isosceles triangle throttling retaining wall bottom edgeThe radian of the arc where the two end points are located.

The isosceles triangle throttling retaining wall close to the straight blade 5 is smoothly connected with the straight blade 5; the bone line of the straight blade 5 is a ray passing through the midpoint of the centrifugal runner 2; the straight blades 5 are evenly arranged along the circumferential direction.

As shown in fig. 1, the straight blade 5 starts from the bottom edge of the isosceles triangle throttle retaining wall 4 and ends at the outlet of the centrifugal runner 2; the isosceles triangle throttling retaining wall 4 close to the straight blade 5 is smoothly connected with the straight blade 5; the bone line of the straight blade 5 is a ray passing through the midpoint of the centrifugal runner 2; the straight blades 5 are evenly arranged along the circumferential direction.

As shown in figure 3, in order to ensure the stability of the incoming flow and the accuracy of the simulation, a water inlet section and a water outlet section are respectively additionally arranged at an inlet and an outlet, and the lengths of the water inlet section and the water outlet section are four times of the pipe diameter. Simulating the number Z of straight blades 5 used₁6. The number Z of the simulated isosceles triangle throttle retaining walls 4₂36. The shrinkage η of the simulated example was 0.82.

The working principle is as follows: when the centrifugal rotating wheel rotates at a high speed, a low-pressure area is formed nearby due to the rotating motion of the straight blades, fluid flows from a suction port of the centrifugal rotating wheel to a water outlet, pressure drop is generated nearby the triangular retaining wall due to the reduction of an overflowing section, and flow separation is caused by sudden structural change nearby the tail edge of the triangular retaining wall, so that cavitation is generated; the high-speed rotation of the straight blade increases the pressure of the fluid, the pressure at the downstream of the triangular throttling retaining wall is recovered, the cavitation bubble is collapsed, and the energy is released. Due to the rotation motion of the centrifugal rotating wheel and the non-uniform structure of the spiral volute, the vacuoles generated by the triangular retaining wall can periodically fall off, and the falling frequency of the vacuoles is higher when the rotating speed is higher.

In the simulation, the rotating speed of the centrifugal rotating wheel 2 is 2950r/min, the inlet pressure is 0.1Mpa, and the flow rate is 65m³/h。

The total number of grids used for the simulation was 2.1 x 10⁶Selecting standard kappa turbulence model with convergence accuracy of 1 x 10^-4。

As shown in fig. 4, the strip-shaped gray ribbon behind the triangular throttle retaining wall 4 has the highest void volume content, the color of the strip-shaped gray ribbon is gray, and then the color is changed from gray to white, which means that the void volume fraction is smaller and smaller; the color then changes from white to black again and the void volume fraction continues to decrease until it reaches zero. From the post-processing results of CFX, it can be found that: the downstream of the bottom edge of the isosceles triangle throttle retaining wall 4 has the largest content of cavitation bubbles, and the cavitation bubble volume is reduced from the partition tongue of the spiral volute 1 along the flow direction.

The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.