CN201997406U - Cavitation water jet nozzle - Google Patents

Abstract

The utility model is a cavitation water jet nozzle, which solves the problem that the existing nozzles cannot adapt to the cavitation water jet flushing of high-speed railway catenary insulators. Between the front nozzle (1) and _the rear nozzle (4) there are connected water inlet cavity Q ₁ , air inlet cavity Q ₂ and cavitation cavity Q ₃ . The axes of the chemical cavity Q ₃ form an included angle, and the water inlet cavity Q ₁ has a first cylinder, a first cone, and a second cylinder, the diameter of the first cylinder D ₁ : 10-15mm, and the length L ₁ : 5-7mm , taper angle β ₁ of the first cone: 30-35°, diameter d ₁ of the second cylinder: 1.8-2.5mm, length L ₂ : 5-7mm, the cavitation cavity Q ₃ has a third cylinder, the second Cone and fourth cylinder, diameter D ₃ of the third cylinder: 18-25mm, length L ₃ : 33-40mm, taper angle β ₂ of the second cone: 30-35°, diameter d ₃ of the fourth cylinder: 5-7mm, length L ₄ : 6-9mm, air inlet diameter D ₃ of air inlet cavity Q ₃ ≥ 4mm, gas outlet diameter d ₂ : 1-2mm, air outlet axis of air inlet cavity Q ₂ is away from the first cone Top distance L ₅ : 15-18mm.

Description

Cavitation water jet nozzle

Technical field:

The utility model relates to a cavitation water jet nozzle for flushing catenary insulators of high-speed rail.

Background technique:

In industrially developed countries, high-pressure water jet cleaning technology has become the mainstream cleaning technology, especially in the heat exchange equipment cleaning and pipeline cleaning of petrochemical enterprises, more than 80% of them use high-pressure water jet cleaning. With the application of high-pressure water jet cleaning technology The breadth and depth of the water jet have been continuously improved, and the high-pressure water jet technology has shown a momentum of rapid development. It has shifted from simply increasing the jet pressure of the water jet in the past to studying and improving the overall impact effect of the water jet (such as erosion effect, jet impact energy, etc.), Many new jets, such as pulse jet, cavitation jet, ultra-high pressure jet and abrasive jet, have appeared one after another, giving full play to the advantages of high-pressure water jet cleaning. Cavitation water jet is a new high-efficiency jet technology with high efficiency, environmental protection and low cost. Studies have shown that under the same pump pressure, the impact pressure of the cavitation jet is 8.6-124 times that of the continuous jet. Using this method, it can be cleaned, rusted, etc., and the injection pressure can be reduced by 1-2 levels under the same level as the high-pressure water jet. The so-called cavitation jet is to artificially generate many cavities in the water jet stream, and use the strong impact force produced by the rupture of the cavities to enhance the effect of the jet. Since the cavitation water jet can produce a large number of cavitation bubbles during the formation process, when these cavitation bubbles reach the high-pressure zone and collapse, they will generate a huge compression wave or micro-jet flow on the nearby solid surface, causing the surface to break, that is, the cavitation effect. . Although this kind of cavitation effect has always been avoided in hydraulic machinery due to cavitation and noise hazards, if it is fully utilized for its strong action on solids, its usable value can be realized in engineering. The impact crushing ability of cavitating jet is also significantly higher than that of non-cavitating jet in theory, and it has great application potential in surface cleaning, rock crushing, material cutting, etc. The basic principle of cavitating jet is simply that in liquid jet Induce cavitation and make the cavity grow. When the jet containing these cavities hits the object, the cavity will be broken on the surface of the object and its vicinity. Because the energy generated when the cavity breaks is highly concentrated, it is confined to many very Small area, resulting in extremely high impact pressure and stress concentration in many local areas on the surface of the object, causing rapid damage to the surface of the object. Under the same pump pressure and flow rate conditions, the partial pressure amplification effect of the cavitating jet makes the cleaning and cutting effect much better than that of the non-cavitating jet.

The key to affecting the cavitation flushing effect of catenary insulators is the structure of the cavitation nozzle within a certain spray distance range, and the liquid flow parameters are also closely related to the flushing performance. Because too strong cavitation will damage the surface of the object to be washed, causing cavitation damage or other damage, and too weak cavitation will not achieve a good washing effect; domestic and foreign studies have also shown that the excitation of external conditions can also make the jet flow produce Cavitation, the more common acoustic cavitation, electromagnetic dynamic cavitation and aerated cavitation. However, the existing air-entrained cavitation nozzles do not have a good flushing effect on the insulators, or have cavitation damage.

Utility model content:

The purpose of the utility model is to provide a cavitation water jet nozzle which saves water, has low cleaning cost and has a good flushing effect on the catenary insulator of the high-speed rail.

The utility model is achieved in that:

The utility model of the cavitation water jet nozzle, the front nozzle 1 is connected with the gun barrel 7, there is a water inlet Q ₁ connected between the front nozzle 1 and the rear nozzle 4, the gas inlet Q ₂ and the cavitation chamber Q ₃ , the water The inlet cavity Q ₁ is coaxial with the cavitation cavity Q ₃ , the air outlet axis of the gas inlet cavity Q ₂ on the air nozzle is at an angle with the axis of the cavitation cavity Q ₃ , and the cavity of the water inlet cavity Q ₁ has successively from the inlet The first cylinder, the first cone, the second cylinder, the diameter D ₁ of the first cylinder: 10-15mm, the length L ₁ : 5-7mm, the taper angle β ₁ of the first cone: 30-35°, The diameter of the second cylinder d ₁ : 1.8-2.5mm, the length L ₂ : 5-7mm, the cavitation chamber Q ₃ has the third cylinder, the second cone and the fourth cylinder in sequence from the water inlet to the water outlet, and the third cylinder Cylinder diameter D ₃ : 18-25mm, length L ₃ : 33-40mm, taper angle β ₂ of the second cone: 30-35°, fourth cylinder diameter d ₃ : 2-7mm, length L ₄ : 6- 9mm, the gas inlet diameter D ₂ of the gas inlet cavity Q ₂ ≥ 4mm, the gas outlet diameter d ₂ : 1-2mm, the distance L ₅ between the gas outlet axis of the gas inlet cavity Q ₂ and the top of the first cone: 15-18mm.

The gas inlet axis of the gas inlet cavity _Q2 is coaxial or perpendicular to the gas outlet axis.

The inlet pressure P ₁ of the water inlet Q ₁ : 0.4-1.6MPa, the inlet pressure P ₂ of the air inlet Q ₂ : 0.2-0.8MPa.

Front nozzle 1, rear nozzle 4 and gas nozzle 2 are separate elements, and the two ends of front nozzle 1 are threadedly connected with gun barrel 7 and rear nozzle 4 respectively, and there is a seal at the joint, and gas nozzle 2 is welded or threaded with front nozzle 1.

The annular air duct of the air inlet coaxial with the water inlet is arranged on the front nozzle 1 to communicate with the built-in gas nozzle 9, and the built-in gas nozzle 9 is located between the front nozzle 1 and the rear nozzle 4, and has an air outlet.

The key to affecting the cavitation flushing effect of catenary insulators lies in the structure of the cavitation nozzle within a certain spray distance range, and the liquid flow parameters will also affect the flushing effect. Too strong cavitation will damage the surface of the object to be washed to cause cavitation or other damage, and too weak cavitation will not achieve a good washing effect; the utility model has the advantages of simple structure, low manufacturing cost and convenient use. Cavitation is generated by passing water flow, and cavitation is stimulated by doping gas. It can be used for the flushing of targets within a certain range of stroke distance, and is matched with the flushing of catenary insulators of high-speed railways. It has the characteristics of water saving and good flushing effect, and will not cause cavitation or other damage to insulators. The cleaning speed is fast and the cleaning cost is low.

Description of drawings:

Fig. 1 is one of structure drawing of the present utility model.

Fig. 2 is the second structural diagram of the utility model.

Fig. 3 is the third structural diagram of the utility model.

Detailed ways:

The utility model is made up of front nozzle 1, rear nozzle 4, gas nozzle 2 or built-in gas nozzle 9, seal, gun barrel 7, and front nozzle 1 is fixedly connected with gun barrel 7 to form water inlet mouth Q1. The front part of the water inlet mouth is cylindrical, the middle part is conical, and there is an orifice d1, and the pressure water flow is passed into the gun barrel 7, and the direction of the water flow is X; Air, air flow direction Y, air inlet Q2 has a throttle hole d2, the rear nozzle 4 is fixedly connected with the front nozzle 1 to form a cavitation chamber Q3, the front section is cylindrical, the middle part is conical, and there is a throttle hole d3, There is a seal between the joint surfaces of each component, which is used to prevent the fluid in the water inlet cavity Q1, the air inlet cavity Q2, and the cavitation cavity Q3 from leaking out at the joint parts of the components. The main parameters are D1, D2, D3; d1, d2, d3; L1, L2, L3, L4, L5; β1, β2, water pressure P1, air pressure P2, the parameters are: D1: 13mm, D2≥4mm, D3: 20mm; d1: 2.21mm, _d2 : 1.5mm., d3: 6mm; L1: 6mm, L2: 6mm, L3: 38mm, L4: 7mm, L5: 17mm; β1: 33°, β2: 32; P1 : 1.0MPa, P2: 0.5MPa

Under the premise of ensuring the above main parameters, the utility model can change the local structure without changing the flushing effect, thereby deriving other structures, and these derived local structures are also within the scope of protection of this patent. The gas nozzle 2 is welded on the front nozzle 1 as shown in Fig. 2 . A built-in air nozzle 9 is added between the front nozzle 1 and the rear nozzle 4 of the structure shown in Figure 3. Through the built-in air nozzle 9, the air flow is allowed to enter the ring-shaped air inlet cavity Q ₂ in the axial direction, so that the water pipe and the air pipe can be coaxial. Nested joins.

According to the theory of fluid mechanics, under the condition of constant temperature, if the small effect of surface tension when forming small bubbles is ignored, when the local absolute pressure of the liquid flow is reduced to the saturated vapor pressure at the current temperature, the liquid originally contained a small The gas bubbles (often referred to as gas nuclei) will expand rapidly, forming cavities containing water vapor or other gases inside the liquid flow, creating cavitation. In the utility model, the water flow direction X of a certain pressure continuously flows through the circular column part, the conical part and the orifice _d1 of the water inlet _Q1 . According to the flow law, the speed of the orifice increases sharply, and the cavitation Firstly, the solid inner wall surface of this shrinkage section is inoculated and enters the cavitation cavity Q ₃ , and then enters the low-pressure area, the pressure drops sharply, is lower than the saturated vapor pressure, and the cavitation develops and grows, inducing large bubbles, and in the low-pressure area Inner growth; the airflow of a certain pressure flows continuously along the Y direction through the cylindrical part of the air inlet _Q2 and the orifice _d2 , and the compressed air is introduced into the cavitation chamber _Q3 and mixed with water to form a two-phase flow, which can Enhance the effect of disturbance and cavitation, as the two-phase flow moves in the cavitation chamber Q ₃ , and in the cone and the orifice d ₃ , the pressure increases, and the cavitation shrinks and collapses. Therefore, the whole process of the cavitation phenomenon should include three stages: the gestation and initial birth of the cavitation, the development and growth, and the shrinkage and collapse. Each stage (or sub-process) in the whole process depends on the mechanism parameters of the nozzle and the change of water flow and air pressure. When the two-phase flow jet containing these cavities hits the object, the cavities are broken on the surface of the object and its vicinity. Since the energy generated when the cavities are broken is highly concentrated and confined to many very small areas, there are many bubbles on the surface of the object. The local area produces extremely high impact pressure and stress concentration, which quickly destroys the dirt on the surface of the washing object. The utility model can make the surface of the insulator well washed without damaging the insulator by providing reasonable nozzles and pressure parameters of water and air.

Claims (5)

1. The cavitation water jet nozzle is characterized in that the front nozzle (1) is connected to the gun barrel (7), and there is a water inlet mouth (Q ₁ ) connected between the front nozzle (1) and the rear nozzle (4). The inlet cavity (Q ₂ ) and the cavitation cavity (Q ₃ ), the water inlet cavity (Q ₁ ) is coaxial with the cavitation cavity (Q ₃ ), the air outlet axis of the air inlet cavity (Q ₂ ) on the air nozzle is in line with the air The axis of the chemical cavity (Q ₃ ) forms an included angle, and the cavity of the water inlet cavity (Q ₁ ) has a first cylinder, a first cone, and a second cylinder in sequence from the entrance, and the diameter of the first cylinder D ₁ : 10 -15mm, length L ₁ : 5-7mm, taper angle β ₁ of the first cone: 30-35°, diameter d ₁ of the second cylinder: 1.8-2.5mm, length L ₂ : 5-7mm, cavitation cavity (Q ₃ ) There is a third cylinder, a second cone and a fourth cylinder in sequence from the water inlet to the water outlet. The diameter of the third cylinder D ₃ : 18-25mm, the length L ₃ : 33-40mm, the second cone Taper angle β ₂ : 30-35°, fourth cylinder diameter d ₃ : 5-7mm, length L ₄ : 6-9mm, gas inlet diameter D ₂ of the gas inlet cavity (Q ₂ ) ≥ 4mm, gas outlet diameter d ₂ : 1-2mm, distance L ₅ between the air outlet axis of the air inlet cavity (Q ₂ ) and the top of the first cone: 15-18mm. 2. The cavitation water jet nozzle according to claim 1, characterized in that the air inlet axis of the air inlet cavity (Q ₂ ) is coaxial or perpendicular to the air outlet axis. 3. The cavitation water jet nozzle according to claim 1, characterized in that the inlet pressure P ₁ of the water inlet cavity (Q ₁ ): 0.4-1.2MPa, and the inlet pressure P ₂ of the air inlet cavity (Q ₂ ): 0.2 -0.8MPa. 4. The cavitation water jet nozzle according to claim 1, characterized in that the front nozzle (1), the rear nozzle (4) and the gas nozzle (2) are separate elements, and the two ends of the front nozzle (1) are respectively connected to the gun barrel (7) is threadedly connected with the rear nozzle (4), and a seal is arranged at the joint, and the gas nozzle (2) is welded or threaded with the front nozzle (1). 5. The cavitation water jet nozzle according to claim 1, characterized in that the front nozzle (1) has an annular air channel coaxial with the water inlet and has an air inlet to communicate with the built-in gas nozzle (9), and the built-in gas nozzle (9) Located between the front nozzle (1) and the rear nozzle (4), there is an air outlet. the

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