How to clean cast aluminum heater?
Machining often leaves some metal scraps in the tube shell, and a lot of dust will accumulate in the tube that has been stored for a long time. If they are not removed, the capillary channel will be blocked.
The remaining water in the aluminum or stainless steel tube shell can react chemically with the tube wall to generate non-condensable gas, which not only corrodes the tube shell, but also blocks the condensing section, making the heat pipe unable to operate normally.
In addition, cleaning is also necessary for the welding of parts, and the quality of the weld is closely related to the cleanliness of the surface of the parts.
The cleaning process generally consists of oil removal, oxide film removal, washing and drying. Solvents (alcohol, carbon tetrachloride, etc.) can be used for degreasing, or chemical degreasing (such as sodium hydroxide solution) can be used. The removal of the oxide film depends on the material. For aluminum and aluminum alloy, lye can be used, and for copper, copper alloy and stainless steel, acid corrosion can be used. Then rinse with clean water, dry and save. Here, we give the cleaning process of aluminum and aluminum alloy, copper and copper alloy and stainless steel. Of course, other suitable processes can also be used.
It should be pointed out that the time should not be too long for both pickling and alkaline cleaning to prevent excessive corrosion, especially for axial grooved pipes and spiral grooved pipes. Excessive corrosion will widen the channel and reduce the capillary force.
The frequently used copper mesh has a small metal wire diameter, which is not suitable for cleaning in acid. Can be used after soaking in solvent to remove oil. The inside of the sintered die is already very clean and does not need to be cleaned. If cleaning is necessary, it can be immersed in a solvent and then baked for a long time to volatilize all the solvent remaining in the tube core.
In addition, both lye and acid are corrosive to different degrees and will emit harmful gases during cleaning. For example, when copper reacts with acid, grade gas is released. When vertical gas escapes through acid liquid, acid mist is formed. Therefore, cleaning should be carried out in an environment with good ventilation equipment.