合成膜电阻片喷涂过程的雾化仿真（英文）

Simulation of atomization uniformity in the synthetic film potentiometer spraying process

合成膜电阻片是合成膜电位计中的关键零部件,其电阻的线性度直接决定了电位计的精度。喷涂电阻液是合成膜电阻片制造过程中的关键工序,因为喷涂的均匀性对电阻片的电阻线性度有至关重要的影响。影响喷涂均匀性的因素主要有电阻液本身的均匀性、电阻液雾化的均匀性、喷枪与电阻片相对运动速度的均匀性以及喷涂室流场的分布特性等。对电阻液雾化进行了分析,利用有限元仿真,得到了雾化气体压力、电阻液流量以及喷涂距离对电阻液雾化均匀性的影响规律。对于口径0.5 mm的喷枪,当电阻液流量恒定,雾化压力从0.2 MPa增加到0.4 MPa时,雾化均匀区间从距离喷嘴260 mm处变到距离喷嘴150 mm处;当雾化压力恒定,电阻液流量从1.89×10^(-5)kg/s增加到4.89×10^(-5)kg/s时,雾化均匀区间从距离喷嘴130 mm处变大到距离喷嘴200 mm处。这些仿真结果将为电阻液喷涂工艺提供一定的参考。

Synthetic film resistor is the key component of synthetic film potentiometer,and the linearity of synthetic film resistor directly determines the accuracy of the potentiometer. Spraying is the key machining process of synthetic film potentiometer manufacturing because spraying uniformity has crucial influence on the linearity of resistance. Factors that affect the spraying uniformity are the uniformity of atomization,the uniformity of relative speed between spray gun and synthetic film resistorand the distribution characteristics of the spray chamber flow field,etc. In this paper,the atomization of toluene was analyzed,and how air pressure,mass flow rate of toluene and spray distance influence the atomization uniformity was obtained. For the spray gun with nozzle diameter of0. 5 mm,when the flow rate of toluene is constant and air pressure gets increased from 0. 2 MPa to 0. 4 MPa,the distance between the uniform atomization area and nozzle is in the range from 260 mm to 150 mm. When the air pressure is constant,mass flow rate of toluene gets increased from 1. 89 × 10^-5kg / s to 4. 89 × 10^-5kg / s,the distance between uniform atomization area and nozzle is in the range from 130 mm to 200 mm.