| The heat transfer area of thin-walled inner-ribbed copper tube is two to three times of that of common tube which has no inner ribs, so it is widely used in the industries of refrigeration, air-condition etc. The traditional process of inner-ribbed copper tube includes the formations of tube and inner ribs which have the disadvantages of complicated process, huge investment in equipments, high consumption of energy, low finished product rate and difficulty to guarantee surface quality.Heated-mold continuous casting (O.C.C, Ohno continuous casting) is a new near-net-shape processing method and a revolution to traditional machining process. Inner-ribbed copper tube that has the ideal shape and dimensions can be casted directly from copper liquid through only one step.Success of casting thin-walled inner-ribbed copper tube by the vertical O.C.C equipment depends on whether the S+L interface can be kept in position. The location of S+L interface in the mold is determined by cooling distance, mold temperature, casting speed. Calculating results show that the temperature field of casting is linear from S+L interface to cooling point. It is reasonable to control the location of S+L interface by measuring the temperature of one point outside casting mold and adjusting cooling distance. The reaction speed is slow by measuring mold temperature with thermocouple and adjusting cooling distance by hand, so it can not meet the need of industrialization. Copper transfers heat well. The temperature records through computer serial communication show that it has a more rapid reaction speed to measure temperature by infrared thermometer than by thermocouple.It is very important to confirm the dummy ingot tube joint copper liquid very well before casting. When the setting value of mold temperature is 1080℃, the temperature inside mold is higher than it, the thin dummy ingot tube has melted before casting. So the melted copper liquid must fill the slot between outside mold... |
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