Method of dry cleaning inside wall of flared tube

Abstract

This invention discloses a dry cleaning method for stains on the inner wall of a flared tube. The method involves inserting a cleaning needle, longer than the flared end, into the flared end of the tube. The front end of the cleaning needle forms a seal with the tapered hole created during the flaring process. A cleaning space is provided between the flared inner hole of the tube and the outer diameter of the matching cleaning needle. An injection hole is provided along the axial direction of the cleaning needle, and a jet nozzle is provided laterally at the bottom of the injection hole, leading to the cleaning space. The airflow injected from the injection hole into the cleaning space flows backward along the inner wall of the flared inner hole, blowing away the stains adhering to it. This method solves a series of problems associated with traditional technologies such as water-based cleaning agents and solvent cleaning, including complex production processes, wastewater and VOC emissions, low production efficiency, and high costs. The method cleans stains effectively, eliminates concerns about rust, is non-toxic and harmless, ensures safe operation, is simple in process, has high production efficiency, and produces reliable product quality.

Description

Technical Field

[0001] This invention relates to refrigerator heat exchange tube manufacturing technology, and in particular to a dry cleaning method for stains on the inner wall of a flared tube. Background Technology

[0002] During the manufacturing of refrigerator heat exchanger tubes, the ends need to be flared. During this flaring process, carbon deposits are generated due to the use of flaring fluid and temperature increases. Residual flaring oil also adheres to the inner wall of the tube, forming stains. If these stains are not cleaned properly, they will affect subsequent brazing processes, causing serious quality problems in the finished product.

[0003] For stains on the inner walls of small-diameter pipes, the existing cleaning methods mainly include the following:

[0004] One method involves solvent cleaning followed by drying. After flaring the opening, the container is placed in an organic solvent cleaning tank for cleaning, and then allowed to air dry. The disadvantage of this method is that the use of organic solvents is not only harmful to human health but also generates significant VOC emissions.

[0005] The second method involves water-based ultrasonic cleaning → water washing (repeated water washing) → passivation → water washing → drying. The disadvantages of this method are: a long process route, low efficiency, and the generation of a large amount of wastewater, increasing environmental pressure; high production costs and energy consumption, hindering energy conservation and emission reduction; a potential quality hazard due to the possibility of the inner wall of the pipe not being completely dried, easily causing ice blockage in the refrigerator; and the possibility of rusting during drying. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems and provide a dry cleaning method for stains on the inner wall of a flared pipe. It uses compressed air to flush the volatile flaring liquid, carbonized substances generated during flaring, and flaring oil and other adhering stains on the inner wall of the pipe under reverse high pressure. It has the characteristics of simple process, no VOC emission, low cost, high operation efficiency and stable quality.

[0007] The above-mentioned technical problems of the present invention are mainly solved by the following technical solution: a dry cleaning method for stains on the inner wall of a flared tube, characterized in that: a cleaning needle with a length greater than the flaring length is inserted into the flared end of the processing tube, the front end of the cleaning needle forms a seal with the tapered hole formed by the flaring process, a cleaning space is left between the flared inner hole of the processing tube and the outer diameter of the cleaning needle that cooperates with it, an injection hole is provided along the axial direction of the cleaning needle, compressed air is injected into the injection hole, and a jet hole is provided laterally at the bottom end of the injection hole leading to the cleaning space.

[0008] The cross-section of the injection hole is larger than the cross-section of the gap formed between the outer diameter of the cleaning needle and the flared inner hole of the processing tube.

[0009] The airflow injected from the injection hole into the cleaning space is pushed out in the opposite direction along the inner wall of the flared forming bore of the processing tube, blowing away the stains adhering to the inner wall of the flared forming bore of the processing tube.

[0010] In the aforementioned dry cleaning method for stains on the inner wall of a flared tube, preferably, the airflow injected from the injection hole into the gap space formed by the outer diameter of the cleaning needle and the inner hole of the flared tube is a turbulent or spiral airflow.

[0011] In the aforementioned dry cleaning method for stains on the inner wall of a flared tube, preferably, the compressed air injected into the injection hole is a pulsed airflow.

[0012] In the aforementioned dry cleaning method for stains on the inner wall of a flared tube, preferably, the jet holes horizontally provided at the bottom of the injection hole are evenly distributed around the circumference of the injection hole wall.

[0013] In the aforementioned dry cleaning method for stains on the inner wall of a flared tube, preferably, the air jets are symmetrically distributed around the injection hole wall, and the air jets form an acute angle with one diameter of the circle of the injection hole.

[0014] In the aforementioned dry cleaning method for stains on the inner wall of a flared tube, preferably, the cleaning needle includes a needle seat, a needle rod arranged coaxially with the needle seat, and a needle cone located at the front end of the cleaning needle; the outer diameter of the needle seat is larger than the outer diameter of the needle rod, the length of the needle rod is larger than the length of the flared inner hole of the processed tube, and the difference between the length of the needle rod and the length of the flared inner hole of the processed tube constitutes a sewage discharge area.

[0015] In the aforementioned dry cleaning method for stains on the inner wall of a flared tube, preferably, the airflow introduced into the injection hole is dry air with a humidity range of 1% to 5%.

[0016] In the aforementioned dry cleaning method for stains on the inner wall of a flared pipe, preferably, the sewage discharge area is sealed and collected to a sewage collection device.

[0017] In the aforementioned dry cleaning method for stains on the inner wall of a flared pipe, preferably, the cleaning space is maintained at 0.1 to 0.3 mm on one side.

[0018] This technical solution, based on the characteristics of refrigerator heat exchange tubes (condenser tubes) with short flared lengths and small orifices, designs a cleaning needle that mates with the inner hole of the flared end of the processed tube. An air cleaning needle is inserted into the steel tube, with its tapered head tightly gripping the inner wall of the tube. Utilizing the tapered orifice formed by the flaring process, the front end of the cleaning needle seals the original tube hole's starting point, creating a tiny space with the flared inner hole of the processed tube. This exposes all dirt within this small space. Compressed air is then supplied through the injection hole located in the central channel of the cleaning needle and via a jet nozzle at the bottom of the flared inner hole, spraying high-pressure air towards the wall of the flared inner hole. The compressed air then flows backward along the inner wall of the flared inner hole, and the shearing force generated by the high-pressure gas blows the dirt out of the tube, achieving the cleaning purpose.

[0019] The solution features a natural alignment and positioning between the needle tip and the tapered hole of the processing tube. It is simple to operate and follows the natural flow. Simply apply appropriate pressure along the end of the cleaning needle to meet the sealing requirements, preventing contaminated gas from entering the original tube hole. It also stabilizes the coaxiality of the cleaning needle and the processing tube, ensuring that all parts of the flared inner hole are thoroughly cleaned.

[0020] The design of the jet orifice can achieve the purging effect of turbulent or spiral airflow. Turbulent flow, also known as turbulent flow, occurs when the flow velocity increases significantly, making streamlines no longer clearly discernible. Many small vortices are formed in the flow field, and there is not only sliding but also mixing between adjacent flow layers, forming turbulent flow. This disordered and diffused airflow can thoroughly clean various stains adhering to the inner hole of the flared forming. Spiral airflow is an airflow with specific rotational characteristics. It moves in a spiral form and has a certain direction and rotational speed. This airflow form has a better shearing force on the inner wall surface of the cylindrical tube, just like polishing.

[0021] In addition, this solution also incorporates pulsed airflow and dry air applications to ensure successful cleaning of the inner hole during flaring and to keep the product surface dry, thus preventing rust.

[0022] This technical solution is particularly suitable for dry cleaning of the flared end of heat exchange tubes with a diameter of less than 5mm.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: by using the airflow purging dry cleaning method, the present invention completely solves a series of problems such as complex production processes, wastewater and VOC emissions, low production efficiency, and high costs of traditional technologies such as water-based cleaning agents and solvent cleaning. The stains are cleaned thoroughly, there is no concern about rust, it is non-toxic and harmless, the operation process is safe, the process is simple, the production efficiency is high, and the product quality is reliable. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an operational state structure according to the present invention.

[0025] Figure 2 This is a schematic diagram of a cleaning needle structure according to the present invention.

[0026] Figure 3 This is a schematic diagram of the flared end structure of the processing tube that needs to be cleaned according to the present invention.

[0027] In the diagram: 1-cleaning needle, 101-needle seat, 102-needle bar, 103-needle cone, 104-injection hole, 105-air jet hole, 2-processing tube, 201-flared inner hole, 202-conical hole, 203-original tube hole, 3-stain.

[0028] A-Discharge Zone. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0030] This embodiment describes a dry cleaning method for stains on the inner wall of a flared pipe, which is a dry cleaning method using a cleaning needle 1. Taking a refrigerator steel pipe as an example, the end of the pipe is oiled using conventional techniques, followed by a flaring process to obtain a semi-finished processed pipe 2. Figure 3 As shown, the tube includes the original tube hole 203 and the flared inner hole 201, which serves as the brazing mating part for the next process. Between the original tube hole 203 and the flared inner hole 201 is a tapered hole 202. Due to the characteristics of the flaring process, a small amount of oil stains will remain on the opening of the processed tube 2 (which will later form stain 3). As the flaring process is advanced, the oil stains gradually decrease until they disappear.

[0031] This embodiment also includes an air compressor, an air dryer, a clamping device for the processing tube 2, a fixing and pushing / removing mechanism for the cleaning needle 1, and an automated control system, etc., all of which are implemented using conventional technical means and will not be described in detail here.

[0032] The main hardware design object in this embodiment is the cleaning needle 1, such as... Figure 2 As shown, the device comprises a needle base 101 with the largest diameter, a needle bar 102 coaxially arranged with the needle base 101, and a needle cone 103 located at the foremost end of the cleaning needle 1. The outer diameter of the needle base 101 is larger than the outer diameter of the needle bar 102, and the length of the needle bar 102 is greater than the length of the flared inner hole 201 of the processing tube 2. An injection hole 104 is provided along the central axis of the cleaning needle 1, and compressed air is forced into the injection hole 104. The injection hole 104 reaches the needle cone 103. An air jet hole 105 is provided laterally at the bottom end of the injection hole 104, leading to the cleaning space.

[0033] Several important parameters for design:

[0034] First, the cross-section of the injection hole 104 is larger than the cross-section of the gap formed between the outer diameter of the cleaning needle 1 and the flared inner hole 201 of the processing tube 2. The purpose is to create a larger pressure difference and promote the generation of an air knife with shearing force. For the steel pipe of the refrigerator in this embodiment, a cleaning space is left between the flared inner hole 201 of the processing tube 2 and the outer diameter of the needle rod 102 of the cleaning needle 1 that matches it. This cleaning space only needs to be 0.1 to 0.3 mm on each side.

[0035] Secondly, the airflow injected from the injection hole 104 into the gap space formed by the outer diameter of the cleaning needle 1 and the flared inner hole 201 of the processing tube 2 is turbulent or spiral airflow.

[0036] The turbulence effect is generated by multiple jet holes 105 that are horizontally arranged at the bottom of the injection hole 104 and are evenly distributed around the wall of the injection hole.

[0037] To achieve the spiral airflow effect: Multiple jet holes 105 are symmetrically distributed around the wall of the injection hole 104, and the jet holes 105 form an acute angle with one of the diameters of the circle of the injection hole 104, such as 45 degrees.

[0038] Third, the compressed air injected into the injection hole 104 is a pulsed airflow, forming an intermittent airflow jet.

[0039] Fourth, the airflow into the injection hole is dry air with a humidity range of 1% to 5%. Using dry air keeps the surface being blew dry and prevents rust spots.

[0040] During cleaning, the processing tube 2 is fixed by a clamping device, and the cleaning needle 1 is fixed on the push-pull-out moving mechanism to maintain the coaxial position of the processing tube 2 and the cleaning needle 1. When batch processing of a single specification product, the push-pull-out moving mechanism does not need to be replaced.

[0041] See Figure 1 The cleaning needle 1 is gently pushed into the flared end of the processing tube 2, so that the needle cone 103 at the front end of the cleaning needle 1 and the cone hole 202 formed by the flaring process form a sealed fit. The outer diameter of the needle rod 102 of the cleaning needle 1 and the flared inner hole 201 of the processing tube 2 form a cleaning space. The difference between the length of the needle rod 102 and the length of the flared inner hole 201 forms the sewage discharge area A. The sewage discharge area A is sealed and collected to the sewage collection device.

[0042] External dry compressed air is injected into the clean space through injection hole 104 and jet hole 105. The airflow rushes out in the opposite direction along the wall of the flared inner hole 201 of the processing tube 2. The air knife shearing force formed by the high pressure gas blows away the dirt 3 adhering to the inner wall of the flared inner hole 201 of the processing tube 2.

[0043] Each processing tube 2 is continuously rinsed 3 times with pulsed airflow. After completion, the cleaning needle 1 is removed, and the processing tube 2 is taken out to proceed with the next workpiece operation.

[0044] The above embodiments are illustrative of the present invention and not intended to limit it. Although the present invention has been described in conjunction with preferred embodiments, it should be understood that the present invention is not limited to the preferred embodiments. Those skilled in the art can make various equivalent modifications and substitutions to the technical solutions of the present invention based on the teachings of the present invention. Therefore, the scope of the present invention should be defined by the claims, and all such equivalent modifications and substitutions fall within the protection scope of the present invention.

Claims

1. A dry cleaning method for stains on the inner wall of a flared pipe, characterized by: A cleaning needle (1) with a length greater than the flared length is inserted into the flared end of the processing tube (2). The front end of the cleaning needle forms a seal with the tapered hole (202) formed by the flaring process. The flared inner hole (201) of the processing tube and the outer diameter of the cleaning needle that matches it leave a cleaning space. An injection hole (104) is provided along the axial direction of the cleaning needle. Compressed air is pressed into the injection hole (104). A jet hole (105) is provided laterally at the bottom end of the injection hole to lead to the cleaning space. The cross-section of the injection hole is larger than the cross-section of the gap formed between the outer diameter of the cleaning needle and the inner hole of the flared processing tube. The airflow injected from the injection hole into the cleaning space is pushed out in the opposite direction along the inner wall of the flared forming of the processing tube, blowing away the stains (3) adhering to the inner wall of the flared forming of the processing tube.

2. The method for dry cleaning stains on the inner wall of a flared pipe according to claim 1, characterized in that, The airflow injected from the injection hole (104) into the gap space formed by the outer diameter of the cleaning needle and the flared inner hole (201) of the processing tube is turbulent or spiral airflow.

3. A dry cleaning method for stains on the inner wall of a flared pipe according to claim 1 or 2, characterized in that, The compressed air injected into the injection hole (104) is a pulsed airflow.

4. A dry cleaning method for stains on the inner wall of a flared pipe according to claim 1 or 2, characterized in that, The jet holes (105) provided laterally at the bottom end of the injection hole (104) are evenly distributed around the wall of the injection hole.

5. A dry cleaning method for stains on the inner wall of a flared pipe according to claim 1 or 2, characterized in that, The jet holes (105) are symmetrically distributed around the wall of the injection hole (104), and the jet holes form an acute angle with one of the diameters of the circle of the injection hole.

6. The method for dry cleaning stains on the inner wall of a flared pipe according to claim 1, characterized in that, The cleaning needle (1) includes a needle seat (101), a needle bar (102) arranged coaxially with the needle seat, and a needle cone (103) located at the front end of the cleaning needle; the outer diameter of the needle seat is larger than the outer diameter of the needle bar, the length of the needle bar is larger than the length of the flared inner hole (201) of the processing tube, and the difference between the length of the needle bar and the length of the flared inner hole of the processing tube constitutes the sewage discharge area (A).

7. A dry cleaning method for stains on the inner wall of a flared pipe according to claim 1, 2, or 6, characterized in that, The airflow introduced into the injection port is dry air with a humidity range of 1% to 5%.

8. A dry cleaning method for stains on the inner wall of a flared pipe according to claim 6, characterized in that, The sewage discharge area (A) is sealed and collected into the sewage collection device.

9. A dry cleaning method for stains on the inner wall of a flared pipe according to claim 1, characterized in that, The clean space is maintained at 0.1 to 0.3 mm on each side.

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