Noise Growth Mechanism and Sound Pressure Level on the Noise of Rice Transport Pipe in Rice-Drying and Storage Facility

1.总结了碾米机环境噪声声级的特点。碾米机噪声声级为76~90分贝(A)，全天等效声级为78~83分贝(A)。可以看出，全天的噪声暴露水平主要由碾米机工作所暴露的声能大小决定。本文总结了抛米器在大米输送管道中的噪声特性。大米输送管道的噪声水平主要是由大米与管壁之间的摩擦和碰撞引起的。流动稻谷的噪声谱主要由高频噪声构成。大米与大米输送管道材料之间的摩擦系数和噪声声级的特征总结如下。噪声水平随着摩擦系数的增大而增大。噪声水平随材料移动速度的增加而增加，但摩擦系数一般随移动速度的增加而减小。总结了大米与大米输送管道材料的碰撞能量和噪声水平的特点。噪声水平随着碰撞能量的增加而增加。大米与大米输送管道材料碰撞产生的噪声普遍高于摩擦产生的噪声。

1. The characteridtics of the environmental noise levels in the rice mill were summarized as follows. The noise levels in the rice mill were 76-90dB(A), and the equivalent sound levels during all over the day ranged from 78dB(A) to 83dB(A). It can be seen that noise exposure levels during all over the day were mostly determined by amounts of the sound energy exposed by rice mill works.2. The characteristics of the noise levels of the rice transport pipe by using the thrower were summarized as follows. The noise levels of the rice transport pipe were caused mainly friction and collision between rice and pipe wall. Noise spectrum of flowing rice were constituted mainly high frequency noise.3. The characteristics of the coefficient of friction and the noise levels between rice and materials of rice transport pipe were summarized as follows. The noise levels increased as the coefficient of friction were increased. The noise levels increased as the moving speed of the materials were increased, but the coefficient of friction generally decreased with an increase in the moving speed.4. The characteristics of the collision energy and the noise levels between rice and materials of the rice transport pipe were summarized as follows. The noise levels increased as the collision energy were increased. The noise levels arising the collision between rice and materials of the rice transport pipe were generally higher than that arising the friction.