Air-assisted feed feeding nozzle

Abstract

The invention provides an air-assisted feed feeding nozzle, and belongs to the technical field of feed equipment. The air-assisted feed feeding nozzle comprises an inlet section, a throat pipe and an expansion section which are coaxially and sequentially connected in the airflow direction; the ratio of the diameter D2 of the throat pipe to the diameter D3 of the outlet of the expansion section is greater than or equal to 0.3 and less than or equal to 0.5, and the divergence angle beta of the expansion section is 12-15 degrees. The inlet diameter D1 of the inlet section ranges from 44 mm to 48 mm, a convergence taper angle alpha is formed in the inlet section, and the angle range of the convergence taper angle alpha ranges from 18 degrees to 25 degrees. The throat pipe has an axial length L1, and the ratio of the axial length L1 to the diameter D2 of the throat pipe is larger than or equal to 0.8 and smaller than or equal to 1.5. The invention has the beneficial effects that through optimization of main parameters such as the throat diameter ratio, the divergence angle and the like, the advantages of long range and wide coverage for small-particle-size feed can be realized under the conditions of low air pressure and low air volume, and meanwhile, the nozzle has the characteristics of high wear resistance and blockage prevention, the maintenance frequency and the replacement cost are effectively reduced, and the service life of the nozzle is prolonged. The urgent requirements of modern aquaculture on accurate, efficient and energy-saving feeding are met.

Description

Technical Field

[0001] This invention relates to the field of feed equipment technology, and in particular to a pneumatic feed dispensing nozzle. Background Technology

[0002] In the aquaculture industry, pneumatic feed delivery systems have gradually become standard equipment in large-scale farms due to their advantages such as high efficiency, uniform distribution, and significant reduction in labor intensity. The core component of this system is the feeding nozzle, and its performance directly determines the feeding effect and system operating efficiency.

[0003] However, the commonly used pneumatic feed nozzles on the market still have a series of unresolved technical problems in practical applications: First, to achieve sufficient feeding range, traditional nozzles usually reduce the throat diameter or increase the fan power, relying on high air pressure and large air volume for delivery. This not only increases fan energy consumption, resulting in high operating costs, but also makes it difficult to optimize the entire system in terms of noise, size, and cost. Second, there is a problem of easy clogging, especially when feeding small-diameter or powdery feed with a particle size of less than 1.2mm. Often, due to unreasonable internal flow channel design of the nozzle, such as improper angle of the contraction or expansion section, eddies or local low-pressure areas are easily generated, causing feed particles to accumulate and stick together, eventually clogging the flow channel. This not only interrupts the continuous feeding process and affects the normal feeding of farmed animals, but also increases the operational burden due to frequent cleaning and maintenance. Finally, since existing nozzles often lack consideration for the synergistic effect of key parameters such as expansion angle and throat diameter ratio during design, if a small expansion angle is used in pursuit of excessive range, the coverage area will be too narrow; conversely, if an excessively large expansion angle is used in order to expand coverage, it is easy to cause the airflow to separate prematurely in the expansion section, resulting in a sharp loss of kinetic energy and a significant reduction in range, which will affect the overall growth uniformity of the aquaculture population.

[0004] Therefore, there is an urgent need for a feeding nozzle that can operate stably under low wind pressure and energy consumption, effectively prevent feed blockage, and balance range and coverage width to meet the pressing needs of modern aquaculture for precise, efficient, and energy-saving feeding. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and provides a pneumatic feed nozzle that achieves multiple advantages such as low energy consumption, high performance, long range, and wide coverage.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: A pneumatic feed nozzle includes an inlet section, a throat, and an expansion section coaxially connected in sequence along the airflow direction; the ratio of the diameter D2 of the throat to the outlet diameter D3 of the expansion section satisfies: 0.3≤D2 / D3≤0.5, and the expansion angle β of the expansion section is 12° to 15°.

[0007] Furthermore, the inlet diameter D1 of the inlet section is 44mm to 48mm, and the inlet section forms a converging cone angle α, the angle range of which is 18° to 25°; the throat has an axial length L1, and the ratio of the axial length L1 to the throat diameter D2 satisfies: 0.8≤L1 / D2≤1.5.

[0008] Furthermore, the axial length L1 of the throat and the throat diameter D2 satisfy the following relationship: L1 = 1.2 × D2; and / or, The length L2 of the expansion segment is determined according to the following formula: L2=(D3-D2) / (2×tan(β / 2)).

[0009] Furthermore, the inner wall of the throat is provided with a wear-resistant insert; the wear-resistant insert is made of tungsten carbide and its surface Vickers hardness HV≥1800.

[0010] Furthermore, the wear-resistant insert has a microporous air film structure inside, and the microporous air film structure is connected to an external auxiliary air source.

[0011] Furthermore, the inner wall of the expansion section is provided with a spiral guide groove; or, the inner wall of the expansion section is detachably equipped with an angle-adjustable guide plate.

[0012] Furthermore, the body of the nozzle is made of fiber-reinforced engineering plastic.

[0013] Furthermore, the fiber-reinforced engineering plastic is glass fiber reinforced nylon.

[0014] Furthermore, the glass fiber in the glass fiber reinforced nylon has a mass fraction of 15% to 30%.

[0015] Furthermore, the inner wall of the inlet section is provided with an inlet chamfer; the nozzle is connected to the feeding pipeline via a quick-release clamp.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The pneumatic feed nozzle of this invention achieves a balance between low energy consumption and high performance through optimization of key parameters such as throat diameter ratio and expansion angle. Under low air pressure and low air volume conditions, it achieves the advantages of long range and wide coverage for small-particle feed. At the same time, it has high wear resistance and anti-clogging characteristics, effectively reducing maintenance frequency and replacement costs, and meeting the urgent needs of modern aquaculture for precise, efficient and energy-saving feeding. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and are used together with the embodiments of the invention to explain the invention. They do not constitute a limitation of the invention. In the drawings: Figure 1 This invention relates to a three-dimensional pneumatic feed dispensing nozzle. Figure 1 ; Figure 2 This invention relates to a three-dimensional pneumatic feed dispensing nozzle. Figure 2 ; Figure 3 This is a cross-sectional view of the middle section of the air-assisted feed nozzle described in this invention; Figure 4 This is a top-view plan view of the particles in the projection area, verified by CFD simulation.

[0018] In the diagram: 1. Inlet section; 101. Inlet chamfer; 2. Throat; 3. Expansion section. Detailed Implementation

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] like Figures 1 to 3 As shown, the present invention provides a pneumatic feed nozzle, which achieves the effect of long-range, wide coverage and anti-clogging feeding of small-particle feed under low wind pressure conditions through the coordinated design and parameter optimization of the three-part structure of inlet section 1, throat 2 and expansion section 3.

[0021] Specifically, this pneumatic feed nozzle includes an inlet section 1, a throat 2, and an expansion section 3 connected coaxially in sequence along the airflow direction. The inlet section 1 is used to connect to the feeding pipeline and guide the airflow and feed particles to enter smoothly. In one preferred embodiment, the inlet diameter of the inlet section 1 is designed to be 44mm to 48mm, with an optimal value of 46mm. Verification has shown that this size design can reduce the inlet flow velocity to 6-8m / s, effectively reducing inlet pressure loss.

[0022] The inlet section 1 has a converging cone angle α, which is in the range of 18° to 25°, preferably 20°. Verification has shown that this angle range effectively balances the smoothness of airflow acceleration with the compactness of the overall structure, avoiding airflow separation due to an excessively large angle or a lengthy structure due to an excessively small angle.

[0023] To further facilitate installation, the inner wall of the end of the inlet section 1 is also machined with an inlet chamfer 101. The inlet chamfer 101 effectively guides the feeding pipe to be inserted quickly and accurately. In this embodiment, the nozzle is connected to the feeding pipe through a quick-release clamp. Compared with the traditional threaded connection, this design can shorten the installation time and reduce manufacturing costs.

[0024] The throat 2 is the acceleration zone of the nozzle. In this embodiment, the ratio of the diameter D2 of the throat 2 to the outlet diameter D3 of the expansion section 3 satisfies: 0.3 ≤ throat 2 diameter D2 / outlet diameter D3 ≤ 0.5. This throat diameter ratio is the basis for achieving a high throat velocity at low airflow rates.

[0025] In one of the most preferred embodiments, the ratio of throat diameter D2 to outlet diameter D3 is 0.375. That is, throat diameter D2 is 15.0 mm and outlet diameter D3 is 40.0 mm. According to theoretical calculations, at an airflow of 45 m³ / h, the throat velocity of this design can reach approximately 42.4 m / s, which is much greater than the critical suspension velocity of 1.2 mm pellet feed, thus ensuring that the feed pellets are effectively carried and accelerated, fundamentally preventing blockage.

[0026] The throat 2 has a specific axial length L1, the ratio of which to the throat 2 diameter D2 satisfies: 0.8 ≤ throat 2 length L1 / throat 2 diameter D2 ≤ 1.5. This aspect ratio range ensures that the particles achieve sufficient and stable acceleration within the throat 2, while avoiding unnecessary pressure loss due to excessive length.

[0027] Furthermore, in one specific embodiment, the length and diameter of the throat 2 satisfy the following relationship: throat 2 length L1 = 1.2 × throat 2 diameter D2. That is, when the throat 2 diameter D2 is 15.0 mm and the throat 2 length L1 is 18.0 mm, this ratio has been proven to keep the pressure drop to a minimum while ensuring acceleration performance.

[0028] Given that the throat section 2 is subjected to the most severe erosion and wear from the feed pellets, this invention incorporates a wear-resistant insert on the inner wall of the throat section 2. This wear-resistant insert is preferably a ring-shaped structure made of tungsten carbide, fixed to the throat section 2 substrate by interference fit or adhesive. Its surface Vickers hardness is not less than 1800, and an ultra-hard tungsten carbide coating is preferred, thereby significantly improving the nozzle's wear resistance life.

[0029] As a further improvement, to achieve anti-clogging and drag reduction, a microporous gas film structure can be incorporated inside the wear-resistant insert. The microporous gas film structure is connected to an external auxiliary gas source through an internal flow channel. When a small amount of gas is introduced, a uniform gas film can be formed on the inner wall surface of the wear-resistant insert. This can further reduce the frictional resistance between particles and the wall surface and effectively prevent the adhesion of fine particles.

[0030] The expansion section 3 is used to convert the kinetic energy of the high-speed airflow and particles into range and control the coverage area. The expansion angle β of the expansion section 3 is set between 12° and 15°, and in this embodiment, β is 14°. This angle range is the critical diffusion angle to avoid airflow separation during expansion, maximizing the coverage width while ensuring range. The length L2 of the expansion section 3 is determined based on its geometry, specifically calculated using the formula L2=(D3-D2) / (2×tan(β / 2)). That is, when the outlet diameter D3 is 40.0 mm, the throat diameter D2 is 15.0 mm, and the expansion angle β is 14°, the length L2 of the expansion section 3 is approximately 101.9 mm.

[0031] To further optimize the uniformity of feed diffusion in the air, additional structures can be added to the inner wall of the expansion section 3. Specifically, spiral guide channels can be fabricated, or angle-adjustable guide vanes can be detachably installed. These structures can apply a tangential component to the gas-solid two-phase flow exiting the throat 2, thereby breaking the symmetrical flow field and making the feed particles more uniformly distributed in an elliptical or fan-shaped pattern within the projection area.

[0032] In this embodiment, the nozzle body is made of fiber-reinforced engineering plastic to achieve lightweight structure and cost control. Preferably, glass fiber reinforced nylon is used, wherein the mass fraction of glass fiber is 15% to 30%, and most preferably 20%. This material modification scheme can achieve weight reduction while ensuring structural strength and deformation resistance.

[0033] Table 1 below shows the design basis and verification standards for optimizing the main parameters of this feeding nozzle:

[0034] Table 1 Example Effects 1. Through simulation verification, the nozzle with the above-mentioned optimized parameters was validated under the conditions of an air volume of 45 m³ / h and conveying 1.2 mm pellet feed: Throat velocity: v2 = Q / A2 = (45 / 3600) / (π*(0.015 / 2)) 2 The velocity is approximately 42.4 m / s. Conclusion: This is much greater than the critical suspension velocity for 1.2 mm particles (21 m / s), indicating a reasonable design.

[0035] Range and coverage area: Outlet velocity: v3 = v2 * (D2 / D3) 2 ≈42.4*(15 / 40) 2 ≈6.0m / s.

[0036] Range estimation: Using the ballistic-settlement correction model, the theoretical range is ≥4.0 meters at an installation height of 1.8-2.0m.

[0037] Coverage width: Based on a diffusion angle of 12°-14° and turbulent diffusion, the theoretical value of the end coverage width is ≥1.8 meters.

[0038] 2. CFD simulation verification: 1.2mm pelleted feed, 45m³ / h air volume Expected results: Flow field: throat velocity 42-43 m / s, outlet velocity 5.8-6.2 m / s, no obvious flow separation in expansion section 3.

[0039] Particle trajectory: range 3.9-4.3 meters, coverage width 1.7-2.0 meters.

[0040] Uniformity: Coefficient of variation (CV) of particle distribution <15%.

[0041] Pressure drop: 0.9-1.1 kPa for the nozzle body.

[0042] Landing point coverage map: as shown Figure 4 As shown, CFD post-processing can generate a top-down plan view, showing that the particles are uniformly distributed in an elliptical or fan-shaped pattern within the projection area.

[0043] Verification shows that the air-feeding nozzle of the present invention achieves a balance between low energy consumption and high performance through optimization of core parameters such as throat diameter ratio and expansion angle. Under low air pressure and low air volume conditions, it achieves the advantages of long range and wide coverage for small-particle feed, while also possessing high wear resistance and anti-clogging characteristics, effectively reducing maintenance frequency and replacement costs, and meeting the urgent needs of modern aquaculture for precise, efficient and energy-saving feeding.

[0044] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pneumatic feed dispensing nozzle, characterized in that, It includes an inlet section, a throat, and an expansion section connected coaxially in the airflow direction; the ratio of the diameter D2 of the throat to the outlet diameter D3 of the expansion section satisfies: 0.3≤D2 / D3≤0.5, and the expansion angle β of the expansion section is 12° to 15°.

2. The pneumatic feed dispensing nozzle according to claim 1, characterized in that, The inlet diameter D1 of the inlet section is 44mm to 48mm, and the inlet section forms a converging cone angle α, the angle range of which is 18° to 25°; the throat has an axial length L1, and the ratio of the axial length L1 to the throat diameter D2 satisfies: 0.8≤L1 / D2≤1.

5.

3. The pneumatic feed dispensing nozzle according to claim 1 or 2, characterized in that, The axial length L1 of the trachea and the trachea diameter D2 satisfy the following relationship: L1 = 1.2 × D2; and / or, The length L2 of the expansion segment is determined according to the following formula: L2=(D3-D2) / (2×tan(β / 2)).

4. The pneumatic feed dispensing nozzle according to claim 1, characterized in that, The inner wall of the throat is provided with a wear-resistant insert; the wear-resistant insert is made of tungsten carbide and its surface Vickers hardness HV≥1800.

5. The pneumatic feed dispensing nozzle according to claim 4, characterized in that, The wear-resistant insert has a microporous air film structure inside, and the microporous air film structure is connected to an external auxiliary air source.

6. The pneumatic feed dispensing nozzle according to claim 4, characterized in that, The inner wall of the expansion section is provided with a spiral guide groove; or, The inner wall of the expansion section is detachably fitted with an angle-adjustable guide vane.

7. The pneumatic feed dispensing nozzle according to claim 5, characterized in that, The nozzle body is made of fiber-reinforced engineering plastic.

8. The pneumatic feed dispensing nozzle according to claim 7, characterized in that, The fiber-reinforced engineering plastic is glass fiber reinforced nylon.

9. The pneumatic feed dispensing nozzle according to claim 8, characterized in that, The glass fiber reinforced nylon contains 15% to 30% glass fiber by mass.

10. The pneumatic feed dispensing nozzle according to claim 1, characterized in that, The inner wall of the inlet section is provided with an inlet chamfer; the nozzle is connected to the feeding pipeline via a quick-release clamp.

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