Online passivation and corrosion prevention device for aluminum pipe

Abstract

The utility model discloses an on-line passivation anti-corrosion device for an aluminum pipe, which comprises a cooling tank and is characterized in that a liquid input port and a liquid output port are respectively arranged at two ends of the cooling tank in the length direction, and the liquid input port and the liquid output port are externally connected with a passivation liquid system and a single cooling system which are arranged in parallel; the flowing direction of the passivation solution is opposite to the moving direction of the aluminum pipe; a self-cooling mechanism is arranged in the passivation solution system; and a plurality of ultrasonic vibration plates are arranged in the cooling tank. Under the conditions of the same production line length and the same line speed, the passivation reaction time is prolonged, thorough reaction of passivation liquid and the surface of the aluminum pipe is guaranteed, and the corrosion resistance of the aluminum pipe is improved; the temperature of the passivation solution is controlled in real time to realize continuous production; production conditions can be changed according to actual order conditions of workshops, and equipment utilization rate is improved.

Description

Technical Field

[0001] The utility model relates to the anti-corrosion technology of heat exchange aluminum tubes, in particular to an on-line passivation anti-corrosion device for aluminum tubes. Background Art

[0002] Metallic aluminum has many excellent properties, such as low density, high plasticity, easy strengthening, good electrical conductivity, corrosion resistance, easy recycling, weldability, easy surface treatment, etc. However, some properties of aluminum are not very ideal, such as surface properties like hardness, wear resistance, corrosion resistance, etc., which need to be improved and enhanced through surface treatment.

[0003] In order to reduce the economic losses caused by the corrosion damage of aluminum and improve the service life of aluminum products, currently, methods such as anodic oxidation, coating treatment, dipping paint treatment, and adding heat shrinkable tubes are mainly used to improve the corrosion resistance of aluminum tubes. Among them, on-line anti-corrosion of aluminum tubes is relatively difficult.

[0004] The existing extrusion production of aluminum tubes mainly follows the following technological steps: feeding → straightening wheel adjustment → alkali washing → rinsing → extrusion → cooling → passivation → curing → wire drawing → finished product inspection → packaging, etc. To achieve on-line anti-corrosion, it needs to be completed after the passivation step. However, adding a passivation link requires adjusting the production line sequence and length, which has a great impact on the normal production of aluminum tubes. For example, a continuous extrusion aluminum tube on-line passivation device set in Patent Publication No. CN101638779A is connected to the outlet of the formed aluminum tube of a continuous extruder. As a continuous operation system, it consists of a cooling water tank, a water-liquid separator, a passivation tank, and an infrared aluminum tube surface curing device in sequence; the passivation tank is connected to a passivation liquid treatment device, and under the action of a booster pump, the passivation liquid automatically circulates between the passivation tank and the passivation liquid treatment device; among them, the passivation liquid treatment device is provided with an indirect heating device and an automatic temperature control device. The passivation process of this device must be completed within 3 - 5 seconds, and it is only applicable to special passivation liquids and their process conditions; moreover, the cooling tank and the passivation tank of this device are separate. Since the temperature of the extruded aluminum tube is relatively high, in a limited liquid, the longer the production time, the higher the temperature. Therefore, it is also impossible to ensure long-term continuous production unless a sufficiently long cooling tank is configured, which is not practical. Summary of the Invention

[0005] The purpose of the utility model is to solve the above problems, and provide an on-line passivation anti-corrosion device for aluminum tubes, which has the characteristics of ensuring a complete passivation process, guaranteeing the passivation temperature, improving the anti-corrosion performance of aluminum tubes, and being easy to operate under the condition of the original production line cooling tank length or the shortest cooling tank length.

[0006] The above technical problems of the present utility model are mainly solved by the following technical solutions: An on-line passivation and anti-corrosion device for aluminum pipes, including a cooling tank, characterized in that a liquid inlet and a liquid outlet are respectively arranged at both ends of the cooling tank in the length direction, and the liquid inlet and the liquid outlet are externally connected to a passivation liquid system and a single cooling system arranged in parallel; the flow direction of the passivation liquid is opposite to the moving direction of the aluminum pipe; the passivation liquid system has its own cooling mechanism; several ultrasonic vibrating plates are arranged in the cooling tank.

[0007] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, the passivation liquid system includes a passivation tank, the passivation liquid is sent into a chiller by a water pump, the chiller reaches the liquid inlet through a third valve, and the liquid outlet reaches the passivation tank through a second valve, thereby forming a passivation cooling circulation route.

[0008] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, the liquid outlet and the liquid inlet are respectively connected to the single cooling system through a first valve and a fourth valve.

[0009] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, a temperature sensing device is provided in the passivation cooling circulation route.

[0010] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, in the passivation cooling circulation route, the passivation liquid circulation and the coolant circulation are separated from each other.

[0011] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, the several ultrasonic vibrating plates are laid on the bottom of the cooling tank without fixation, and the wiring of the ultrasonic vibrating plates is led out by a material of the same quality as the ultrasonic vibrating plates.

[0012] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, an air knife is provided at the aluminum pipe outlet part on the cooling tank, and the air knife blows towards the inner side of the cooling tank.

[0013] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, overflow tanks are respectively provided at the aluminum pipe inlet and outlet parts of the cooling tank, and a liquid return port is provided at the bottom of the overflow tank.

[0014] In the above-mentioned on-line passivation and anti-corrosion device for aluminum pipes, preferably, the aluminum pipe inlet and outlet on the cooling tank are U-shaped notch openings, the width of the U-shaped notch opening is greater than the diameter of the aluminum pipe, and a movable impact limiting plate is provided at the U-shaped notch opening part.

[0015] Based on the cooling tank, this technical solution utilizes two independent hydraulic system working lengths set along the entire length of the cooling tank, namely the passivation liquid system and the single cooling system arranged in parallel. The passivation liquid system is equipped with its own cooling device, which not only ensures the passivation process temperature of the passivation liquid but also provides cooling for the aluminum tube. The flow direction of the passivation liquid is opposite to the moving direction of the aluminum tube. On the one hand, it is conducive to the full contact between the aluminum tube and the passivation liquid. On the other hand, the liquid inlet is the passivation liquid coming out of the chiller, which has the lowest temperature, while the liquid outlet is the contact part with the extruded aluminum tube, which has the highest temperature. This is conducive to the progress of the passivation reaction.

[0016] Several ultrasonic vibration plates are installed in the cooling tank of this device. The ultrasonic vibration plates are directly laid on the bottom of the cooling tank without the need for installation. Their wiring can be led out using stainless steel pipes of the same material without additional holes being drilled in the cooling tank, avoiding leakage caused by the hole-making process. Since the temperature of the extruded aluminum tube is relatively high, generally reaching 500 °C, when it comes into contact with the normal-temperature passivation liquid, it is easy to form a circle of bubbles on the surface of the aluminum tube, preventing the full contact between the passivation liquid and the aluminum tube. The use of the ultrasonic device will break and shake off the surface bubbles, making the passivation reaction complete and sufficient.

[0017] In this solution, the chiller directly circulates to cool the passivation liquid and reduce its temperature. Due to the limited size of the passivation tank and the excessively high temperature of the extruded aluminum tube, the simple circulation of the passivation liquid in the cooling tank (passivation tank) is insufficient to solve the problem of the rapidly rising temperature. The excessively high temperature directly affects the passivation effect. Therefore, the setting of the chiller in this device effectively controls the reaction temperature. The temperature of the passivation liquid can be monitored in real time through a temperature sensing device, and the working state of the chiller can be adjusted in a timely manner.

[0018] An air knife is installed at the aluminum tube outlet part of the cooling tank of this device. After the aluminum tube reacts chemically with the passivation liquid and moves out of the cooling tank, there is still a small amount of passivation liquid adhering to the surface of the aluminum tube, which affects the subsequent winding of the aluminum tube. The air knife can blow away the excess passivation liquid, avoiding waste of the passivation liquid and reducing the impact on the subsequent winding and packing operations of the aluminum tube.

[0019] This technical solution completely changes the general passivation process that requires processes such as alkali etching, neutralization, and removal of grease and oxides on the surface of the aluminum tube. The entire operation process is that the aluminum tube is directly extruded, and in this state, the surface is relatively clean and directly undergoes passivation, thus reducing at least three or more reaction procedures in the existing technology, greatly reducing the overall length of the production line and improving production efficiency.

[0020] Overflow tanks are installed at both the aluminum tube inlet and outlet parts of the cooling tank of this device to collect the overflow liquid in a timely manner for recycling. The movable impact limiting plate at the U-shaped groove opening can reduce the overflow liquid, providing all-round wetting liquid conditions for the aluminum tube. It can be removed when starting to pull the tube, without affecting the starting operation.

[0021] Therefore, compared with the prior art, the beneficial effects of the present utility model are as follows:

[0022] There is no need to distinguish or separately set a cooling tank and a passivation tank. After the aluminum tube is extruded, it directly reacts with the passivation liquid in the cooling tank, cooling down while passivating. Under the condition of the same production line length and the same line speed, the passivation reaction time can be increased, and the anti-corrosion performance of the aluminum tube can be improved.

[0023] The temperature of the passivation liquid is continuously controlled in real time through a chiller, a temperature sensing device, etc., to achieve continuous production.

[0024] The passivation liquid circulation is separated from the external single cooling system (water circulation). When passivation and anti-corrosion are not required, the water circulation is connected through a logic valve, forming an aluminum tube production line. The production status can be changed according to the actual order situation in the workshop, greatly improving the utilization rate of hardware such as equipment.

[0025] The application of the ultrasonic vibration plate effectively removes the bubbles on the surface of the aluminum tube during the passivation process, ensuring a thorough reaction between the passivation liquid and the surface of the aluminum tube.

[0026] It meets the requirements of the continuous flow production line for the forming and passivation of aluminum tubes, and there is basically no waste of the passivation liquid. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of a system of the present utility model.

[0028] Figure 2 It is a schematic partial structural diagram of a cooling tank of the present utility model.

[0029] Figure 3 It is Figure 2 The schematic structural diagram in the A-A direction of

[0030] In the figure: 1 - cooling tank, 101 - overflow tank, 102 - U-shaped notch, 103 - movable impact limiting plate, 104 - return port, 2 - ultrasonic vibration plate, 3 - air knife, 4 - passivation tank, 5 - water pump, 6 - chiller, 7 - first valve, 8 - second valve, 9 - third valve, 10 - fourth valve, 11 - aluminum tube. Detailed Embodiments

[0031] The technical solutions of the present utility model will be further specifically described below through embodiments and in conjunction with the drawings.

[0032] See Figure 1 、 Figure 2, in this embodiment, an on-line passivation and anti-corrosion device for aluminum pipes includes a cooling tank 1. The cooling tank 1 stores a certain amount of liquid. Overflow tanks 101 are respectively arranged at both ends of the inlet and outlet of the aluminum pipe 11, and a liquid return port 104 is arranged at the bottom of the overflow tank. The inlet and outlet of the aluminum pipe 11 on the cooling tank 1 are U-shaped notches 102. The width of the U-shaped notch 102 is set according to the layout of the production line to be greater than the diameter of the aluminum pipe 11 of this production line. A movable impact limiting plate 103 is arranged at the U-shaped notch 102. The width of the movable impact limiting plate 103 is greater than the width of the U-shaped notch 102. The top of the movable impact limiting plate 103 is directly buckled on the top of the wall plate of the cooling tank 1 where the U-shaped notch 102 is located. As Figure 3 shown, it can be taken off by simply pulling it upwards.

[0033] A liquid inlet and a liquid outlet are respectively arranged at both ends of the cooling tank 1 in the length direction. An external passivation liquid system and a single cooling system arranged in parallel are connected through the liquid inlet and the liquid outlet.

[0034] The single cooling system is arranged in a conventional manner and will not be elaborated here.

[0035] Taking the passivation liquid system as an example, the liquid inlet is arranged at the tail end of the cooling tank 1, that is, at the output end of the aluminum pipe 11 based on the moving direction of the aluminum pipe 11. The liquid outlet is arranged at the head of the cooling tank 1, that is, at the end of the cooling tank 1 towards the aluminum pipe extruder. Thus, the flowing direction of the passivation liquid is opposite to the moving direction of the aluminum pipe 11.

[0036] The passivation liquid system has its own cooling mechanism. The cooling mechanism includes a chiller 6. Specifically, the passivation liquid system includes a passivation tank 4 for storing and filtering the passivation liquid. The passivation liquid is sent to the chiller 6 by a water pump 5. The chiller 6 reaches the liquid inlet through a third valve 9. The liquid outlet returns to the passivation tank through a second valve 8. Thus, a passivation cooling circulation route is formed. In this passivation cooling circulation route, the chiller 6 controls the temperature of the passivation liquid in real time through a temperature sensing device. The pipelines in the chiller 6 and the water pump 5 are both made of acid and alkali resistant materials to be applicable to passivation liquids of different properties and models.

[0037] In this passivation cooling circulation route, the circulation of the passivation liquid is separated from the coolant circulation of the chiller 6.

[0038] At the same time, the liquid outlet and the liquid inlet are also respectively connected to an independent single cooling system through a first valve 7 and a fourth valve 10.

[0039] There are also 4 ultrasonic vibrating plates 2 arranged in the cooling tank. The ultrasonic vibrating plates 2 are made of 316 stainless steel. The 4 ultrasonic vibrating plates 2 are laid on the bottom of the cooling tank without fixation, that is, they are naturally placed on the bottom surface of the cooling tank 1. The wiring of the ultrasonic vibrating plates 2 is led out by a stainless steel pipe made of the same material as the ultrasonic vibrating plates, which is 316 stainless steel.

[0040] In the passivation liquid system of this embodiment, the self-cooling mechanism keeps the temperature of the passivation liquid input to the liquid input port at room temperature, such as 40 ± 5 °C.

[0041] Furthermore, an air knife 3 is provided at the outlet of the aluminum pipe 11 on the cooling tank 1, and the air knife blows towards the inner side of the cooling tank 1.

[0042] During operation, it is passivated online; close the first valve 7 and the fourth valve 10, open the second valve 8 and the third valve 9, and turn on the water pump 5 in the passivation tank 4 to make the passivation liquid circulate in the passivation liquid system. The temperature of the passivation liquid is controlled in real time by the temperature sensing device to be 40 °C, and the passivation liquid in the cooling tank 1 is kept higher than the upper part of the semi-circle at the bottom of the U-shaped notch 102, that is, the position where the aluminum pipe 11 is located, so that the aluminum pipe 11 can be completely submerged in the passivation liquid. The aluminum pipe is extruded from the extruder and fixed to the traction device, and the uniform motion is carried out for the operation of cooling and passivating while moving. When the aluminum pipe 11 finishes passivation and leaves the outlet of the cooling tank 1, the surface of the aluminum pipe 11 is purged by the air knife 3 to blow the small amount of liquid adhering to the surface of the aluminum pipe 11 back into the cooling tank 1 or the overflow tank 101.

[0043] Single online cooling: Close the second valve 8 and the third valve 9, open the first valve 7 and the fourth valve 10, and connect to the conventional circulating water single cooling system. Of course, first empty and clean the different liquids in the cooling tank 1.

[0044] The above embodiments are descriptions of the present invention, not limitations of the present invention. Although the present invention is described in combination 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 those equivalent modifications and substitutions belong to the protection scope of the technical solutions of the present invention.

Claims

1. An on-line passivation and anti-corrosion device for aluminum pipes, including a cooling tank (1), characterized in that The liquid inlet and the liquid outlet are respectively arranged at both ends of the cooling tank in the length direction. The liquid inlet and the liquid outlet are externally connected to a passivation liquid system and a single cooling system arranged in parallel; the flow direction of the passivation liquid is opposite to the moving direction of the aluminum pipe (11); the passivation liquid system has its own cooling mechanism; several ultrasonic vibrating plates (2) are arranged in the cooling tank.

2. The on-line passivation and anti-corrosion device for aluminum tubes according to claim 1, characterized in that, The passivation liquid system includes a passivation tank (4). The passivation liquid is sent into a chiller (6) by a water pump (5). The chiller reaches the liquid inlet through a third valve (9). The liquid outlet reaches the passivation tank through a second valve (8), thereby forming a passivation cooling circulation route.

3. An on-line passivation and anti-corrosion device for aluminum tubes according to claim 1 or 2, characterized in that, The liquid outlet and the liquid inlet are respectively connected to the single cooling system through a first valve (7) and a fourth valve (10).

4. An on-line passivation and anti-corrosion device for aluminum tubes according to claim 2, characterized in that, A temperature sensing device is arranged in the passivation cooling circulation route.

5. An on-line passivation and anti-corrosion device for aluminum tubes according to claim 2 or 4, characterized in that, In the passivation cooling circulation route, the passivation liquid circulation and the coolant circulation are separated from each other.

6. An on-line passivation and anti-corrosion device for aluminum tubes according to claim 1, characterized in that, The several ultrasonic vibrating plates (2) are laid on the bottom of the cooling tank (1) without fixation, and the wiring of the ultrasonic vibrating plates is led out by a material of the same quality as the ultrasonic vibrating plates.

7. An on-line passivation and anti-corrosion device for aluminum tubes according to claim 1, characterized in that, An air knife (3) is arranged at the outlet part of the aluminum pipe (11) on the cooling tank (1), and the air knife blows towards the inner side of the cooling tank.

8. An on-line passivation and anti-corrosion device for aluminum tubes according to claim 1, characterized in that, Overflow tanks (101) are respectively arranged at the inlet and outlet parts of the aluminum pipe (11) on the cooling tank (1), and liquid return ports (104) are arranged at the bottoms of the overflow tanks.

9. An on-line passivation and anti-corrosion device for aluminum tubes according to claim 1 or 8, characterized in that, The inlet and outlet of the aluminum pipe (11) on the cooling tank (1) are U-shaped notch openings (102). The width of the U-shaped notch opening is greater than the diameter of the aluminum pipe. A movable impact limiting plate (103) is arranged at the U-shaped notch opening part.

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