A nozzle for an internal sandblasting machine for seamless steel pipes

Abstract

The utility model discloses a seamless steel tube inner sand blasting machine shower nozzle, including the shower nozzle body, the shower nozzle body end is provided with the spray bar, and the inside of shower nozzle body is provided with the sand inlet air channel, one side of sand inlet air channel is provided with the elbow air channel, and one side of elbow air channel is provided with the injection air channel, be provided with the cooling channel on the shower nozzle body. This seamless steel tube inner sand blasting machine shower nozzle, cooling channel is helical distribution, can increase the contact area of cooling medium and shower nozzle body in the same space obviously, makes cooling medium have more sufficient time to absorb the heat that shower nozzle body produces because of high -speed sand particle friction, and the wider channel can avoid vortex to produce, and airflow and sand particle complete the steering more steadily, and the inside diameter of elbow air channel expands, can reduce the impact and vibration that the elastic sand produces to the inner wall, reduce the wear and tear to the sand outlet, guarantee the wear and tear of sand pressure stable improvement quality, reduce the cost of consumables, and the sand outlet of shower nozzle has no obvious wear and tear and the inner surface of steel pipe has no oxide skin residue.

Description

Technical Field

[0001] This utility model relates to the field of sandblasting machines, specifically a sandblasting nozzle for a seamless steel pipe. Background Technology

[0002] Sandblasting technology uses compressed air to propel abrasive particles at high speed onto the inner surface of a workpiece, achieving the effect of removing oxide scale. In seamless steel pipe manufacturing, internal wall sandblasting is a key process for removing oxide scale, directly affecting the corrosion resistance of the steel pipe and the adhesion of subsequent coatings. The nozzle structure on the market, as shown in the instruction manual... Figure 1 As shown: a zoom-type sandblasting method is adopted; according to Zhang Bin's article "Research and Application of Automatic Sandblasting and Rust Removal Device for Oil and Gas Pipelines" (2008), the air-sand mixture can obtain a very high exit velocity during sandblasting, so that the sand particles have greater kinetic energy. However, in actual use: relying solely on the sand-distributing head at the sand outlet will cause uneven sandblasting; due to vibration and the impact angle of the steel sand, the loose sand-distributing head will have a deviation of 5 to 10 degrees and will continue to shift, resulting in oxide scale residue after sandblasting, which affects the service life of the nozzle; therefore, a seamless steel pipe internal sandblasting nozzle is needed to solve the above problems. Utility Model Content

[0003] The purpose of this utility model is to provide a nozzle for a seamless steel pipe internal sandblasting machine to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, a seamless steel pipe internal sandblasting machine nozzle is provided, including a nozzle body, a spray bar at the end of the nozzle body, a sand inlet air passage inside the nozzle body, a bend air passage on one side of the sand inlet air passage, and a jet air passage on one side of the bend air passage. A cooling channel is provided on the nozzle body.

[0005] Furthermore, the turning air passage is located between the jet air passage and the sand inlet air passage, and a booster seat is fixedly installed inside the sand inlet air passage. The booster seat has a booster air passage inside, and the booster air passage is conical.

[0006] Furthermore, the inner diameter of the bend air passage is larger than the inner diameter of the sand inlet air passage, and the angle between the bend air passage and the jet air passage is 145 degrees.

[0007] Furthermore, the inner wall of the jet air passage is provided with guide grooves, and the guide grooves are distributed in a spiral shape.

[0008] Furthermore, the cooling channel is spiral-shaped, and the nozzle body is equipped with an outlet and an inlet, with the outlet located at one end of the cooling channel and the inlet located at the other end of the cooling channel; the flow direction of the medium inside the cooling channel is opposite to the sandblasting direction.

[0009] Furthermore, the nozzle body is generally L-shaped, and multiple sets of force-bearing seats are provided on the outer circumference of the nozzle body end, with the distance between adjacent sets of force-bearing seats being consistent.

[0010] Compared with the prior art, the beneficial effects of this utility model are: 1. This design, by using a bend air passage with an inner diameter larger than the sand inlet air passage, reduces local flow velocity by increasing the flow space, thereby reducing the impact of sand particles on the bend's inner wall, lowering the wear rate, and extending the service life of the spray bar. Simultaneously, the wider channel prevents eddy currents, allowing the airflow and sand particles to complete the turning more smoothly. The enlarged inner diameter of the bend air passage reduces the impact and vibration of the sand pellets on the inner wall, reducing wear on the sand outlet, ensuring stable sand output pressure, improving quality, and reducing consumable costs. There is no obvious wear at the spray nozzle's sand outlet, and no oxide scale residue remains on the inner surface of the steel pipe. 2. This solution guides the airflow and sand particles along a spiral trajectory through a spiral guide groove, allowing the sand particles to gain tangential rotational speed while advancing axially. When the rotating sand particles are sprayed onto the workpiece surface, they will form a sweeping impact, avoiding local over-treatment or under-treatment caused by spraying in one direction. It is especially suitable for complex structural parts such as curved surfaces and grooves. 3. This solution uses a spiral distribution of cooling channels, which can significantly increase the contact area between the cooling medium and the nozzle body in the same space, while extending the flow path of the medium in the channel. This allows the cooling medium more time to absorb the heat generated by the friction of high-speed sand particles in the nozzle body, improving heat exchange efficiency and quickly reducing the temperature of the nozzle body, thus avoiding the degradation of material properties caused by local overheating. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a sandblasting machine nozzle in the prior art; Figure 2 This is a front view schematic diagram of the structure of this utility model; Figure 3 This is a front view of the structure of this utility model; Figure 4 This is a rear view of the structure of this utility model; Figure 5 This is a side view of the structure of this utility model; Figure 6 This is a three-dimensional view of the structure of this utility model.

[0012] The following numbers are labeled in the diagram: 100, Nozzle body; 200, Spray bar; 21, Sand inlet air passage; 22, Turning air passage; 23, Spray air passage; 231, Guide groove; 24, Pressure booster seat; 241, Pressure booster air passage; 25, Cooling passage; 251, Exhaust outlet; 252, Inlet; 26, Force bearing seat. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0014] Please see Figure 2-6 This utility model provides a seamless steel pipe internal sandblasting machine nozzle, including a nozzle body 100, a spray bar 200 at the end of the nozzle body 100, and a sand inlet air passage 21 is opened inside the nozzle body 100. A bend air passage 22 is opened on one side of the sand inlet air passage 21, and a jet air passage 23 is opened on one side of the bend air passage 22. A cooling channel 25 is provided on the nozzle body 100.

[0015] The nozzle body 100 is generally L-shaped, and multiple sets of force-bearing seats 26 are provided on the outer circumference of the end of the nozzle body 100, with the distance between two adjacent sets of force-bearing seats 26 being the same.

[0016] Working Principle: In actual use, high-speed sand particles enter the interior of the spray bar 200 from the nozzle body 100 through the sand inlet air passage 21, the turning air passage 22, and the jet air passage 23. The jet air passage 23, used for sand discharge, has an orifice diameter between 10mm and 14mm and a sand discharge angle of 45°. The enlarged inner diameter of the turning air passage 22 reduces the impact and vibration of the sand pellets on the inner wall, thereby improving the service life of the nozzle. By reducing the impact and vibration of the steel sand during sandblasting, the output pressure is kept stable, improving quality and reducing consumable costs. The nozzle body 100 uses an X60 steel pipe for internal sandblasting. After replacing the nozzle body 100, the air compressor pressure is 1.02 MPa during internal sandblasting and the jet pressure is 0.98 MPa during jetting, and both the output and jet pressures remain stable. After multiple sandblasting operations, there is no obvious wear at the nozzle outlet and no oxide scale residue on the inner surface of the steel pipe.

[0017] In a preferred embodiment, the turning air passage 22 is located between the jet air passage 23 and the sand inlet air passage 21, and a booster seat 24 is fixedly installed inside the sand inlet air passage 21. A booster air passage 241 is opened inside the booster seat 24, and the booster air passage 241 is conical.

[0018] like Figure 2-5As shown: The conical pressurizing air passage 241 utilizes the principle of contraction acceleration in fluid mechanics. When high-speed sand particles enter with the airflow, the cross-section of the air passage gradually narrows from wide to narrow, causing the airflow velocity to increase rapidly within the pressurizing seat 24. According to the Bernoulli effect, the cross-section contraction leads to increased flow velocity and enhanced kinetic energy. This can increase the initial kinetic energy of the sand particles by more than 30%, ensuring that the sand particles obtain sufficient impact force before entering the subsequent air passages, providing a stronger energy foundation for the final cleaning, roughening, and other operations sprayed onto the workpiece surface. At the same time, the conical structure can reduce the diffusion of sand particles during the sand inlet stage, making the sand particles move more concentrated along the axial direction and avoiding energy waste caused by dispersion. In a preferred embodiment, the inner diameter of the bend air passage 22 is larger than the inner diameter of the sand inlet air passage 21, and the angle between the bend air passage 22 and the jet air passage 23 is 145 degrees.

[0019] like Figure 2-5 As shown: The inner diameter of the turning air passage 22 is larger than that of the sand inlet air passage 21: This reduces resistance, lowers wear, and stabilizes the flow. Sand particles need to change their direction of motion at the turning air passage 22. If the inner diameter of the air passage is smaller than or equal to that of the sand inlet air passage 21, the high-speed sand particles will violently impact the inner wall of the turn due to centrifugal force, leading to increased local wear and easy formation of vortices, resulting in energy loss. The design of the inner diameter of the turning air passage 22 being larger than that of the sand inlet air passage 21 can reduce the local flow velocity by expanding the flow space, reduce the impact of sand particles on the inner wall of the turn, reduce the wear rate, and extend the service life of the spray bar 200. At the same time, the wider passage can avoid the generation of vortices, allowing the airflow and sand particles to complete the turning more smoothly, ensuring that the kinetic energy loss is controlled to a minimum, and providing a guarantee for the stable operation of the subsequent spray air passage 23.

[0020] In a preferred embodiment, a guide groove 231 is provided on the inner wall of the jet passage 23, and the guide groove 231 is distributed in a spiral shape.

[0021] like Figure 2-5 As shown: Spiral guide groove 231 on the inner wall of the jet air passage 23: Optimizes trajectory, improves uniformity and coverage; The spiral guide groove 231 guides the passing airflow and sand particles along the spiral trajectory, so that the sand particles gain tangential rotational speed while advancing axially. When the rotating sand particle group is sprayed onto the workpiece surface, it will form a sweeping impact, avoiding local over-treatment or under-treatment caused by single-direction spraying. It is especially suitable for complex structural parts such as curved surfaces and grooves. The spiral motion makes the spray trajectory of the sand particles spread in a conical shape. Compared with straight spraying, the coverage area can be increased at the same distance, reducing the number of repetitive operations; The combination of tangential speed brought by rotation and axial impact force can form a composite effect similar to grinding and impact, which improves the removal efficiency of high hardness coatings and rust layers.

[0022] In a preferred embodiment, the cooling channel 25 is spiral-shaped, and the nozzle body 100 is respectively equipped with an outlet 251 and an inlet 252, with the outlet 251 located at one end of the cooling channel 25 and the inlet 252 located at the other end of the cooling channel 25; the flow direction of the medium inside the cooling channel 25 is opposite to the sandblasting direction.

[0023] like Figure 2 As shown: The cooling channels 25 are spirally distributed, which can significantly increase the contact area between the cooling medium and the nozzle body 100 in the same space, and at the same time extend the flow path of the medium in the channel; allowing the cooling medium more time to absorb the heat generated by the friction of high-speed sand particles in the nozzle body 100, improving the heat exchange efficiency, and quickly reducing the temperature of the nozzle body 100, avoiding the degradation of material properties caused by local overheating, such as thermal fatigue and deformation of metal nozzles; During sandblasting, high-speed sand particles move along the sand inlet channel 21, the turning channel 22, and the jet channel 23. The frictional heat gradually accumulates with the flow of sand particles, and the heat generation is most concentrated at the outlet end of the jet channel 23 because the sand particles have the greatest kinetic energy and the friction is the most intense. Meanwhile, the cooling medium flows in the opposite direction to the sandblasting direction, that is, it flows in from the cooling channel 25 area corresponding to the jet channel 23 and flows out to the area corresponding to the sand inlet channel 21, forming countercurrent heat exchange: the fresh cooling medium with a lower temperature first comes into contact with the area corresponding to the jet channel 23 where the heat generation is most concentrated, and quickly removes the core heat through the maximum temperature difference; the gradually heated medium continues to flow to the area corresponding to the sand inlet channel 21 where the heat generation is less, and absorbs the heat in this area using the remaining cooling capacity. This matches the cooling efficiency with the heat distribution, provides a cooling effect, and avoids local overheating caused by insufficient cooling at the outlet end of the jet channel 23. This protects the structural stability of the nozzle body 100 and prevents high temperature from affecting the kinetic energy of the sand particles, thus preventing the sand particles from softening and breaking due to high temperature.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A nozzle for a seamless steel pipe internal sandblasting machine, comprising a nozzle body (100), characterized in that: The nozzle body (100) is provided with a spray bar (200) at its end, and a sand inlet air passage (21) is provided inside the nozzle body (100). A bend air passage (22) is provided on one side of the sand inlet air passage (21), and a jet air passage (23) is provided on one side of the bend air passage (22). A cooling channel (25) is provided on the nozzle body (100).

2. The nozzle for a seamless steel pipe internal sandblasting machine according to claim 1, characterized in that: The turning air passage (22) is located between the jet air passage (23) and the sand inlet air passage (21), and a booster seat (24) is fixedly installed inside the sand inlet air passage (21). A booster air passage (241) is opened inside the booster seat (24), and the booster air passage (241) is conical.

3. The nozzle for a seamless steel pipe internal sandblasting machine according to claim 2, characterized in that: The inner diameter of the bend air passage (22) is larger than the inner diameter of the sand inlet air passage (21), and the angle between the bend air passage (22) and the jet air passage (23) is 145 degrees.

4. The nozzle for a seamless steel pipe internal sandblasting machine according to claim 3, characterized in that: The inner wall of the jet air passage (23) is provided with guide grooves (231), and the guide grooves (231) are distributed in a spiral shape.

5. The nozzle for a seamless steel pipe internal sandblasting machine according to claim 1, characterized in that: The cooling channel (25) is spiral-shaped. The nozzle body (100) is equipped with an outlet (251) and an inlet (252), with the outlet (251) located at one end of the cooling channel (25) and the inlet (252) located at the other end of the cooling channel (25). The flow direction of the medium inside the cooling channel (25) is opposite to the sandblasting direction.

6. The nozzle for a seamless steel pipe internal sandblasting machine according to claim 1, characterized in that: The nozzle body (100) is generally L-shaped, and multiple sets of force seats (26) are provided on the outer circumference of the nozzle body (100) end. The distance between two adjacent sets of force seats (26) is consistent.

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