Protective gas on-line purging copper tube bright continuous annealing furnace

Abstract

The continuous copper tube bright annealing furnace features that there are air intake pipe and air exhaust pipe in the material rack; copper tube inner purging unit and inner air exhaust unit in the front chamber, heating chamber, water cooling chamber and forcing cooling chamber; that all the air intake pipes are communicated and so do the air exhaust pipes. The present invention may be used to produce bright copper tube with inner surface of superhigh cleanness. The annealing furnace also has the features of low manufacture cost, low air consumption, low power consumption, high production efficiency and continuous production.

Description

Technical field: [0001] The invention relates to annealing process equipment for nonferrous metal materials, in particular to a bright continuous annealing furnace with protective gas on-line purging copper tubes. Background technique: [0002] As we all know, in order to obtain different mechanical properties (soft state and semi-hard state) and have brighter inner and outer surfaces, copper tubes need to be annealed at different temperatures in an annealing furnace in a protective atmosphere or in a vacuum state. One of the existing bright annealing furnaces for copper tubes is a (vertical or horizontal) movable furnace with a seal. Then put the furnace into the heating furnace for heating, and then place the heated furnace outside for cooling treatment. After the room temperature is cooled, the furnace door is sealed and the copper tube is taken out. This kind of annealing furnace is The overall heating transfer heat and heating the copper tube consumes a lot of power, a...

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Problems solved by technology

One of the existing bright annealing furnaces for copper tubes is a (vertical or horizontal) movable furnace with a seal. Then put the furnace into the heating furnace for heating, and then place the heated furnace outside for cooling treatment. After the room temperature is cooled, the furnace door is sealed and the copper tube is taken out. This kind of annealing furnace is The overall heating transfer heat and heating the copper tube consumes a lot of power, and at the same time, the cooling time is long, the charging material is small, and continuous production is not possible, so the efficiency is low; Continuous bright annealing furnace with vacuum air lock chamber. The feeding area and the discharging area of ​​this kind of annealing furnace are two vacuum air lock chambers. , and then filled with protective gas, and separated by two furnace doors in the heating zone and cooling chamber to prevent the oxidation of copper tubes during the heating and cooling process

The sealing of the above-mentioned annealing furnace is very difficult, especially the front and rear two-stage furnace doors of the heating zone of the continuous annealing furnace manufactured abroad. The furnace door often opens and closes automatically under the condition of high temperature and airtightness in the furnace. The installation, production and maintenance of the sealed pressure mechanism are relatively difficult. At present, there is no self-made continuous bright annealing furnace with a vacuum lock chamber in China; the existing domestic bright annealing furnace with a furnace door is installed outside the furnace. The outer end of the feeding place adopts a heat-resistant 0-type rubber ring, which is easier to cool through the surrounding pressure mechanical seal and cooling water jacket, but it is often deformed and the seal is not tight. Therefore, a large amount of hydrogen (above 10%) is often injected for reduction Bright surface, but copper tubes often cause hydrogen embrittlement defects; In addition, in the past two years, due to the use of fluorine-free copper tubes in air conditioners and refrigerators, it is required to use coils with a large coil weight (150-300kg / coil), and the inner surface requires ultra-high cleaning. Degree less than 20mg / M 2 , it is difficult to extract the air in the coil tube that has been tightly rewound for thousands of meters and the inner diameter is only a few millimeters in a short time by means of vacuuming, and it is also difficult to rely on the protective gas pressure in the furnace cavity to make the coil The tube is filled with protective gas, resulting in partial oxidation and blackening of the tube after annealing, and the residual lubricating oil of the copper tube is heated and volatilized, and then pollutes the inner and outer surfaces of the copper tube

Therefore, in order to obtain a smooth inner surface in the above-mentioned annealing furnace, the manufacturer often cleans the coils one by one outside the furnace, removes oil and fills them with nitrogen. These are very difficult tasks, which increase costs and reduce production efficiency. At the same time, it is difficult to solve the emission of volatiles in the tube during the heating process, so it cannot meet the requirements of copper tubes with ultra-high cleanliness on the inner surface

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