Abstract In order to investigate the movement characteristics of bypass pigs, experimental variables of pressure fluctuation, average and instantaneous pig velocity and pig generated liquid volume were studied by a large experimental pigging system with horizontal, up-and-down, riser pipeline structures. Results obtained in this study show that there are multiple peaks at pressure fluctuation curves and each peak represents a pig pause state. Compared with conventional pigs, bypass pigs which eliminate the significant fluctuation of peak pressure have better adaptability for the variations of liquid loading. Differential pressure at the front and rear ends of the pig, which is self-regulated until a force balance is achieved, is independent of bypass fraction, but hinges on the resistance force. The average pig velocities decrease linearly with the increase of bypass fraction. The instantaneous pig velocities are generally low and less sensitive to the variations of gas flow rates at the bottom of the riser pipe, while it is much higher and exhibits the most obvious downtrend as bypass fraction increases at the top of the riser. When increasing bypass fraction, the duration of terminal liquid outflow is prolonged, indicating bypass pigging is conducive to reducing the pig generated liquid volume.

中文翻译：

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绕道猪运动特性的实验研究

摘要 为了研究旁路清管器的运动特性，采用水平、上下、立管管道结构的大型实验清管器系统研究了压力波动、平均和瞬时清管器速度以及清管器产生的液体体积等实验变量。本研究结果表明，压力波动曲线上有多个峰，每个峰代表一个猪的停顿状态。与常规清管器相比，消除了峰值压力显着波动的旁路清管器对液体负荷的变化具有更好的适应性。清管器前端和后端的压差是自我调节的，直到达到力平衡，与旁路分数无关，但取决于阻力。平均清管速度随着旁路分数的增加而线性下降。瞬时清管器速度通常较低，对立管底部气体流速的变化不太敏感，而随着立管顶部旁通分数的增加，瞬时清管器速度要高得多，并表现出最明显的下降趋势。当增加旁路分数时，终端液体流出的持续时间延长，说明旁路清管有利于减少清管器产生的液体量。