Combined cavitation generator for livestock and poultry breeding wastewater treatment

Abstract

The present invention discloses a combined cavitation generator for livestock and poultry breeding wastewater treatment, comprising a rotor, a stator, a cutter and a gasket. The rotor comprises a front cover plate, a rear cover plate and blades. The partial inner surface of the front cover plate has a first annular protrusion, and a plurality of grooves and blind holes are arranged alternately along the circumference of the first annular protrusion; the rear cover plate is cut at a position opposite to the first annular protrusion and connected to the stator at this position, and the inner surface of the stator has a second annular protrusion opposite to the first annular protrusion; the blades are located downstream of the annular protrusion; the gasket is located between the rotor rear cover plate and the stator; the cutter is located upstream of the annular protrusion, fixed to the center of the rear cover plate, and rotates with the rotor during operation. The present invention can effectively avoid the blockage problem caused by suspended matter in livestock and poultry breeding wastewater, and effectively degrade organic matter in the wastewater under the action of multiple types of combined cavitation, which can promote the harmless treatment of livestock and poultry breeding wastewater.

Description

Technical Field

[0001] The present invention relates to the field of organic wastewater treatment, and in particular to a combined cavitation generator for livestock and poultry breeding wastewater treatment. Background Art

[0002] my country is the world's largest livestock and poultry producer, with total livestock production increasing annually. This results in a significant amount of wastewater discharged from livestock and poultry. The 2020 "Second National Pollution Source Census Bulletin" shows that livestock and poultry farming accounts for 51%, 56%, and 94% of agricultural emissions of ammonia nitrogen (NH4+-N), total phosphorus (TP), and chemical oxygen demand (COD), respectively, representing over half of all agricultural emissions. Livestock and poultry wastewater contains significant amounts of antibiotics, pathogens, parasites, hormones, heavy metals, and macromolecular organic matter. If not promptly treated, it can seriously impact water, soil, and the atmosphere. Currently, physical, chemical, and biological methods are commonly used to treat livestock and poultry wastewater. Experience has shown that these methods often suffer from low efficiency, poor results, and the risk of secondary pollution. Consequently, researchers are exploring new, environmentally friendly wastewater treatment methods. Hydraulic cavitation technology utilizes the intense mechanical, thermal, and chemical effects associated with cavitation collapse to degrade pollutants in wastewater without any pollution, making it a highly promising wastewater treatment method.

[0003] Cavitation generators, devices used to generate cavitation, have been gradually adopted in the field of livestock and poultry wastewater treatment. Orifice plates and Venturi tubes were initially used in livestock and poultry wastewater treatment due to their simple structure and strong cavitation intensity. However, they also suffer from significant problems such as high pressure loss, high energy consumption, and susceptibility to clogging. These shortcomings hinder their large-scale application in livestock and poultry wastewater treatment. Emerging rotary cavitators have, to some extent, addressed the shortcomings of orifice plates and Venturi tubes, promoting green treatment of livestock and poultry wastewater.

[0004] Chinese invention patent application number 202310556856.6 discloses a centrifugal cavitation generator, which has a hollow box with a through-hole unit on the outside of the impeller. Cavitation occurs when the fluid passes through the through-hole unit. However, when the sewage contains suspended matter, the through-hole unit is easily blocked and the cavitation is restricted. At the same time, since the impeller is placed upstream of the through-hole unit, the pressure downstream of the through-hole unit recovers slowly, which not only leads to low cavitation collapse intensity, but also causes the cavitator to have poor sewage transportation capacity, and has to be equipped with other power equipment for fluid transportation, so it needs to be improved. Summary of the Invention

[0005] In response to the above-mentioned defects, the present invention provides a combined cavitation generator for livestock and poultry breeding wastewater treatment, which can not only effectively reduce blockage, but also produce multiple types of combined cavitations to promote the effective degradation of organic matter. In addition, the cavitation generator also has the function of a water pump, which can transport sewage while treating sewage, thereby promoting the application of hydraulic cavitation technology in the field of livestock and poultry wastewater treatment.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] A combined cavitation generator for livestock and poultry breeding wastewater treatment includes a rotor, a stator, a cutter and a gasket, the rotor includes a front cover plate, a rear cover plate and blades, the front cover plate and the rear cover plate are connected in parallel, an annular through hole is provided on the rear cover plate, and the stator is connected in the annular through hole, a protrusion assembly is provided on the rotor, the protrusion assembly includes a first annular protrusion provided on the inner surface of the front cover plate, and a second annular protrusion provided on the inner surface of the stator, the first annular protrusion and the second annular protrusion are arranged opposite to each other, and a plurality of first grooves and a plurality of first blind holes are alternately provided on the first annular protrusion and along its circumference, the blades are located downstream of the protrusion assembly, the cutter is located upstream of the protrusion assembly, the cutter rotates with the rotor, and the gasket is located between the rear cover plate and the stator, and is used to adjust the gap between the first annular protrusion and the second annular protrusion.

[0008] Furthermore, the center line of the protrusion assembly coincides with the rotation axis of the rotor, and the leading edge surface and the trailing edge surface of the protrusion assembly are both cylindrical surfaces, and the inner surface of the protrusion assembly is perpendicular to the rotation axis of the rotor.

[0009] Furthermore, the protrusion assembly is located at δ=D1 / D out =0.45~0.85, wherein D1 is the diameter of the leading edge surface of the protruding component, in mm, D out is the outer diameter of the rotor, in mm;

[0010] The radial length of the protrusion assembly is L=0.2-0.5 (D out -D in ), where D in is the inlet diameter of the rotor, in mm.

[0011] Furthermore, the blade is adjacent to the rear edge of the protruding component, the blade is curved, the wrap angle θ1 of the blade is 45-90°, and the number of the blades z1 is 5-7.

[0012] Furthermore, the center lines of the first grooves and the first blind holes are perpendicular to the surface of the protruding component, and the number of the first grooves and the first blind holes is n1=1~3z1, wherein z1 is the number of the blades.

[0013] Furthermore, the first groove passes through the first annular protrusion, the diffusion angle α of the first groove is 20° to 60°, and the effective depth H of the first groove is g =0.4b~0.6b, where b is the outlet width of the rotor, in mm;

[0014] The diffusion angle of the first blind hole is β=20°~60°, the shape of the first blind hole includes cylindrical, hemispherical, rectangular and conical, and the characteristic width D of the first blind hole is b =0.5L~0.8L, in mm, the characteristic depth H of the first blind hole b =0.5D b ~1.5D b , unit is mm.

[0015] Furthermore, the stator is provided with second grooves and second blind holes, and the number of the second grooves and the second blind holes are equal to the number of the first grooves and the first blind holes, and the shapes are the same and the arrangement is completely consistent;

[0016] The outer diameter D2 of the stator is greater than or equal to 1.1 (D1+2L), in mm. The outer edge of the stator is fixedly connected to the inner wall of the volute by screws. When the cavitation generator is working, the stator is fixed.

[0017] Furthermore, the gasket is divided into two parts, one part is located at the front edge of the annular protrusion of the stator, and the other part is located at the rear edge of the annular protrusion of the stator, and the number of gaskets in both places is n2.

[0018] Furthermore, a gap is provided between the rotor and the stator, and the width W of the gap is adjusted by the gasket and satisfies the expression:

[0019]

[0020] Where W is the width of the gap, in mm, and Q is the flow rate, in m 3 / s, P1 is the inlet pressure of the cavitation generator, the unit is Pa, P v is the saturated vapor pressure of sewage, in Pa, and ρ is the density of sewage, in kg / m 3 , k is the loss coefficient, which is related to the cavitator structure and ranges from 0.2 to 0.35.

[0021] Furthermore, the tool includes a blade, the axial distance S between the blade and the inner surface of the first annular protrusion is 3~5W, in mm, the outer diameter D3 of the blade is 0.75~0.9D1, in mm, the blade is curved, the wrap angle θ2 of the blade is 45~90°, and the number of the blades z2 is 2~4.

[0022] By means of the above technical solution, the beneficial effects of the present invention are as follows:

[0023] 1. The combined cavitation generator for livestock and poultry farming wastewater treatment of the present invention cuts and crushes suspended matter in the wastewater before cavitation occurs, which can not only reduce blockage caused by suspended matter in the wastewater, but also reduce the molecular weight of organic matter in the wastewater, facilitating subsequent cavitation degradation;

[0024] 2. The combined cavitation generator for livestock and poultry wastewater treatment described in the present invention generates various types of cavitation when wastewater passes through the gaps between the annular protrusions, resulting from the interaction between the rotor and the stator. Some cavitation bubbles collapse near the gaps, releasing energy, while the majority of cavitation bubbles collapse in a concentrated manner downstream of the annular protrusions, releasing even more energy. Each time the wastewater passes through the cavitation generator, it is degraded multiple times, thereby improving wastewater treatment efficiency.

[0025] 3. The combined cavitation generator for livestock and poultry wastewater treatment described in the present invention has blades arranged downstream of the cavitation generation area, which can quickly increase the wastewater pressure. On the one hand, it promotes the high-intensity collapse of cavitation bubbles, and on the other hand, it ensures that the wastewater can be transported to a distant place, reducing the use of other power equipment.

[0026] 4. The combined cavitation generator for livestock and poultry breeding wastewater treatment described in the present invention fully considers the actual application scenarios and can achieve cavitation without frequent adjustment of the speed and pressure. In addition, the width of the gap can be controlled by adjusting the number of gaskets, thereby changing the cavitation intensity to meet the treatment needs of wastewater of different concentrations, and has strong adaptability.

[0027] In order to make the above and other objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1Schematic diagram of the three-dimensional structure of the combined cavitation generator of the present invention;

[0030] Figure 2 Schematic diagram of the three-dimensional structure of the rotor of the combined cavitation generator of the present invention;

[0031] Figure 3 A radial cross-sectional view of the rotor of the combined cavitation generator of the present invention;

[0032] Figure 4 A cross-sectional view of the rotor of the combined cavitation generator of the present invention along the axial direction;

[0033] Figure 5 This is a schematic diagram of the three-dimensional structure of the stator of the combined cavitation generator of the present invention;

[0034] Figure 6 This is a cross-sectional view of the stator of the combined cavitation generator of the present invention;

[0035] Figure 7 A schematic diagram of the three-dimensional structure of a tool of the combined cavitation generator of the present invention;

[0036] Figure 8 A plan view of a tool of the combined cavitation generator according to the present invention;

[0037] Figure 9 This is a cross-sectional view of the combined cavitation generator of the present invention.

[0038] The figure marks of the above drawings are: 1. rotor; 2. stator; 3. tool; 4. gasket; 11. front cover plate; 12. rear cover plate; 13. blade; 14. first groove; 15. first blind hole; 21. second groove; 22. second blind hole; 31. blade. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] It should be noted that, in the description of the present invention, the terms "first," "second," etc., are used solely for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0041] Example: Combination Figure 1-9As shown, this embodiment discloses a combined cavitation generator for livestock and poultry breeding wastewater treatment, including a rotor 1, a stator 2, a cutter 3 and a gasket 4. The rotor includes a front cover plate 11, a rear cover plate 12 and blades 13. The front cover plate 11 and the rear cover plate 12 are connected in parallel. The local inner surface of the front cover plate 11 has a first annular protrusion, and a plurality of grooves 14 and blind holes 15 are evenly and alternately arranged on the first annular protrusion and along its circumference; the rear cover plate 12 is cut at a position opposite to the first annular protrusion of the front cover plate 11 and connected to the stator 2 at this position. The local inner surface of the stator 2 has a second annular protrusion with a similar structure to the first annular protrusion; the blade 13 is located downstream of the annular protrusion; the gasket 4 is located between the rear cover plate 12 and the stator 2 to adjust the gap between the annular protrusions of the rotor 1 and the stator 2.

[0042] The gasket 4 is divided into two parts, one located at the leading edge of the annular protrusion of the stator 2, and the other located at the trailing edge of the annular protrusion of the stator 2. There are eight gaskets in both locations. The cutter 3 is located upstream of the annular protrusion and fixed to the center of the rear cover plate 12. It rotates with the rotor 1 during operation.

[0043] like Figures 2 to 6 As shown, the center line of the annular protrusion coincides with the rotation axis of the rotor 1, and the leading edge surface and the trailing edge surface of the annular protrusion are both cylindrical surfaces. The inner surface of the annular protrusion is perpendicular to the rotation axis of the rotor 1. The annular protrusion is located at δ = D1 / D out =0.55, where D1 is the diameter of the front edge of the annular protrusion, in mm, and D out The outer diameter of the rotor 1 is in mm. The radial length of the annular protrusion should not be too long, otherwise it will easily cause the length of the downstream blade 13 to be too short, which will affect the effective collapse of the cavitation bubble and the ability of the cavitator to transport sewage. The effective length L of the annular protrusion is determined by the flow channel size of the rotor 1. The effective length L = 0.2 (D out -D in )=20mm, where D in is the inlet diameter of the rotor 1, in mm.

[0044] The blades 13 are adjacent to the trailing edge of the annular protrusion. The blades 13 are curved with a wrap angle θ1 of 50°, which can provide pressure energy for the cavitation flow to a greater extent, promote cavitation collapse and sewage transportation, and the number of blades 13 z1 is 6.

[0045] The center lines of the grooves 14 and blind holes 15 are perpendicular to the surface of the annular protrusion, and the number of the two is equal, n1 = z1 = 6, where z1 is the number of blades 13; the grooves 14 pass through the annular protrusion, with a diffusion angle α = 20° and an effective depth H g=0.5b=3mm, where b is the outlet width of the rotor 1, in mm; the diffusion angle of the annular convex area where the blind hole 15 is located is β=40°, the shape of the blind hole 15 is cylindrical, and the characteristic width D of the blind hole 15 is b =0.8L=16mm, characteristic depth H of blind hole 15 b =0.8D b =12.8mm; the position of the annular protrusion on the stator 2 is the same as that on the rotor 1, and a second groove 21 and a second blind hole 22 are provided on the stator 2. The number of the second grooves 21 and the second blind holes 22 are equal to the number of the first grooves 11 and the first blind holes 12 on the rotor 1, and the shapes are the same and the arrangement is completely consistent.

[0046] The outer diameter D2 of the stator 2 is 160 mm. The outer edge of the stator 2 is fixed to the inner wall of the volute by screws. When the cavitation generator is working, the stator 2 is fixed. A gap is opened between the rotor 1 and the stator 2. The width W of the gap is adjusted by a gasket and satisfies the expression:

[0047]

[0048] Where W is the width of the gap, which is 3 mm, and Q is the flow rate, in m 3 / s, P1 is the inlet pressure of the cavitation generator, the unit is Pa, P v is the saturated vapor pressure of sewage, in Pa, and ρ is the density of sewage, in kg / m 3 , k is the loss coefficient, which is related to the cavitator structure and has a value of 0.2.

[0049] like Figure 7 、 Figure 8 As shown, the number z2 of blades 31 on the tool 3 is 3, and the tool 3 has a smaller number of blades 31 to prevent suspended matter from being entangled on the blades 31. The distance S=3W=9mm between the blade 31 and the inner surface of the first annular protrusion, the outer diameter D3=0.85D1=85mm of the blade 31, the shape is curved, and the wrap angle θ2 of the blade 31 is 45°.

[0050] Working principle:

[0051] Livestock and poultry wastewater contains a large amount of suspended matter, such as hair and fibers, which can easily clog the cavitator. Therefore, in the present invention, a blade is used to pre-treat the wastewater, reducing the molecular weight of the suspended matter and minimizing the chance of cavitator clogging. When the pre-treated wastewater passes through the gap between the annular protrusions of the rotor and stator, the flow velocity surges and the pressure decreases. Shear cavitation occurs at the leading edge of the annular protrusion, facing the groove water flow, and separation cavitation occurs at the trailing edge of the annular protrusion, facing the groove water flow. Stable vortices form within the blind hole, generating vortex cavitation. Within the gap, localized high-pressure areas exist where cavitation bubbles collapse, releasing energy and achieving a primary treatment of the incoming wastewater. Due to the lower overall pressure within the gap, the degree of cavitation collapse in these areas is low, releasing less energy and achieving a poor pollutant removal effect. However, under the action of the blades, the pressure downstream of the annular protrusion recovers rapidly, creating a large area of ​​high pressure where cavitation bubbles collapse to a high degree, releasing a large amount of energy and achieving a secondary treatment of the wastewater. Simultaneously, the pressurizing effect of the blades allows the wastewater to be transported to a distant location. The present invention utilizes the combined action of multiple types of cavitation to achieve degradation of pollutants in sewage in multiple areas of the cavitator, thereby improving sewage treatment efficiency.

[0052] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0053] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0054] Specific embodiments are used in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A combined cavitation generator for livestock and poultry breeding wastewater treatment, characterized in that: The invention comprises a rotor (1), a stator (2), a cutter (3) and a gasket (4); the rotor (1) comprises a front cover plate (11), a rear cover plate (12) and blades (13); the front cover plate (11) and the rear cover plate (12) are connected in parallel; the rear cover plate (12) is provided with an annular through hole; the stator (2) is connected in the annular through hole; the rotor (1) is provided with a protrusion component, and the protrusion component is located at δ = D1 / D out =0.45~0.85, wherein D1 is the diameter of the leading edge surface of the protruding component, in mm, D out is the outer diameter of the rotor (1), in mm; the radial length of the protrusion assembly L=0.2-0.5 (D out -D in ), where D in is the inlet diameter of the rotor (1), in mm; the protrusion assembly comprises a first annular protrusion provided on the inner surface of the front cover plate (11), and a second annular protrusion provided on the inner surface of the stator (2); the first annular protrusion and the second annular protrusion are arranged opposite to each other, a plurality of first grooves (14) and a plurality of first blind holes (15) are alternately provided on the first annular protrusion and along its circumference, and a second groove (21) and a second blind hole (22) are provided on the second annular protrusion; the blade (13) is located downstream of the protrusion assembly and adjacent to the trailing edge of the protrusion assembly; the tool (3) is located upstream of the protrusion assembly and fixed at the center of the rear cover plate (12), and the tool (3) rotates with the rotor (1); the gasket (4) is located between the rear cover plate (12) and the stator (2) and is used to adjust the gap between the first annular protrusion and the second annular protrusion.

2. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 1, characterized in that: The center line of the protrusion assembly coincides with the rotation axis of the rotor (1), and the leading edge surface and the trailing edge surface of the protrusion assembly are both cylindrical surfaces, and the inner surface of the protrusion assembly is perpendicular to the rotation axis of the rotor (1).

3. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 1, characterized in that: The blades (13) are curved, the wrap angle θ1 of the blades (13) is 45-90 degrees, and the number z1 of the blades (13) is 5-7.

4. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 1, characterized in that: The center lines of the first groove (14) and the first blind hole (15) are both perpendicular to the surface of the protruding component, and the number of the first groove (14) and the first blind hole (15) is n1=1~3z1, where z1 is the number of the blades (13).

5. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 1, characterized in that: The first groove (14) passes through the first annular protrusion, the diffusion angle α of the first groove (14) is 20° to 60°, and the effective depth H of the first groove (14) is g =0.4b~0.6b, wherein b is the outlet width of the rotor (1), in mm; the diffusion angle of the first blind hole (15) is β=20°~60°, the shape of the first blind hole (15) includes cylindrical, hemispherical, rectangular and conical shapes, and the characteristic width D of the first blind hole (15) is b =0.5L~0.8L, in mm, the characteristic depth H of the first blind hole (15) b =0.5D b ~1.5D b , unit is mm.

6. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 1, characterized in that: The number of the second grooves (21) and the second blind holes (22) is equal to that of the first grooves (14) and the first blind holes (15), and the shapes are the same and the arrangement is completely consistent; the outer diameter D2 of the stator (2) is greater than or equal to 1.1 (D1+2L), in units of mm; the outer edge of the stator (2) is fixedly connected to the inner wall of the volute by screws; when the cavitation generator is working, the stator (2) is fixed.

7. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 1, characterized in that: The gasket (4) is divided into two parts, one part is located at the front edge of the annular protrusion of the stator (2), and the other part is located at the rear edge of the annular protrusion of the stator (2), and the number of gaskets in both places is n2.

8. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 1, characterized in that: The width W of the gap is adjusted by the spacer (4) and satisfies the expression: Where W is the width of the gap, in mm, and Q is the flow rate, in m 3 / s, P1 is the inlet pressure of the cavitation generator, the unit is Pa, P v is the saturated vapor pressure of sewage, in Pa, and ρ is the density of sewage, in kg / m 3 , k is the loss coefficient, which is related to the cavitator structure and ranges from 0.2 to 0.

35.

9. The combined cavitation generator for livestock and poultry breeding wastewater treatment according to claim 8, characterized in that: The tool (3) includes a blade (31), an axial distance S between the blade (31) and the inner surface of the first annular protrusion is 3 to 5W, in mm, an outer diameter D3 of the blade (31) is 0.75 to 0.9D1, in mm, the blade (31) is curved, a wrap angle θ2 of the blade (31) is 45 to 90°, and the number z2 of the blades (31) is 2 to 4.

Images