| 摘要 |
PURPOSE:To form a passivation film on the inside surface of a stainless steel pipe, etc., uniformly by subjecting the heated passivating fluid fed into a pipeline constituting body which is to be treated and consists of a stainless steel pipe, etc., to intermediate heating to prevent the temp. drop thereof. CONSTITUTION:The passivating fluid formed by adjusting the steam from a steam generator 6 and the pressurized air from an air compressor 7 to about 100:2 by the weight of air and water flowmeters 11, 12 and a control device 4 respectively is heated to about 310 deg.C by a heater 5 of a boiler 13 and is fed into the pipeline constituting body 1 which is to be treated and consists of the stainless steel pipe 2 and piping parts 3. The passivating fluid is further heated by an intermediate heater 8 in the mid-way of the body 1 and the temp. of the down flow in proximity thereto is measured by a thermometer 14. The intermediate heating quantity is adjusted by the control device 4 in accordance with the measured value, by which the temp. in the longitudinal direction of the pipeline is made uniform. If a narrow part N exists in said body, a dummy pipe 15 is preferably provided by branching the pipeline to make uniform the Raynolds number in each part of the body 1 and to decrease the uneven flow rate of the passivating fluid.
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