Acid-washing method for internal surfaces of metal capillary tubes

Abstract

The invention discloses an acid-washing method for internal surfaces of metal capillary tubes, which comprises the following steps of: 1, the trimming and fixing of tubes to be acid-washed; 2, tube insertion; and 3, acid washing, wherein in the trimming and fixing of the tubes to be acid-washed, bottom ends of a plurality of upright metal capillary tubes to be acid-washed are aligned, and lower parts of the upright metal capillary tubes to be acid-washed are hooped tightly by a sealing washer 1 to form an upright metal capillary tube bundle; in the process of tube insertion, the sealing washer 1 is ensured to be always fixed to the lower part of the metal capillary tube bundle, and the peripheral outer wall of the metal capillary tube bundle is always in close contact with the inner wall of a vertical acid-washing cylinder; and in the acid washing process, after the plurality of metal capillary tubes to be acid-washed are immersed into acid-washing liquid completely, the acid-washing process of the internal surfaces of the metal capillary tubes to be acid-washed is completed by the conventional acid-washing method. The acid-washing method has the advantages of novel and reasonabledesign, low invested cost, simple acid-washing steps, convenient realization, good acid-washing effect and capability of realizing the acid-washing process of the metal capillary tubes of which the inner diameters are less than or equal to 2 millimeters simply and conveniently and realizing the acid-washing process of the internal surfaces of the plurality of metal capillary tubes at one time simultaneously.

Description

technical field [0001] The invention relates to a method for surface treatment of metal pipes, in particular to a method for pickling the inner surface of metal capillary pipes. Background technique [0002] Metal pipes generally need to undergo surface pickling during the production process or before the finished product leaves the factory. The pickling process in the pipe processing process is usually arranged before and after intermediate heat treatment (or annealing). Among them, the main purpose of pickling before heat treatment is to remove the oxide layer generated during processing, and at the same time play a role in degreasing; pickling after heat treatment is mainly used to remove the oxide layer generated in the heat treatment stage to avoid the presence of oxidation inclusions in subsequent processing Which affects the performance of the pipe. The finished pickling is generally bright pickling, the purpose is to improve the surface quality of the pipe. [0003...

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Problems solved by technology

[0003] For pipes with an inner diameter of more than 2mm, the effect of surface tension is slight, and the acid liquid can flow smoothly in the pipe to realize the pickling process; but when the inner diameter of the pipe is less than 2mm, the effect of surface tension of the liquid is significantly enhanced, and it is difficult for the acid liquid to flow in the pipe , or cannot flow into the inside of the pipe, the reason is that when the acid liquid comes into contact with the gas inside the pipe, a surface layer will be formed, and the molecules in the surface layer of the liquid are sparser than the inside of the liquid, so they are subject to the force directed to the inside of the liquid, making The surface of the liquid has a tendency to shrink; at the same time, affected by the cohesive force between the liquid molecules, the liquid surface automatically shrinks, so that the acid liquid minimizes its surface area and does not flow into the capillary tube, making pickling impossible.

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