Abstract: To solve the problem of non-uniform fouling removal and scale prevention in the heat exchanger tube with vibrating spiral-insert cleaning technology,a vibrating and reciprocating spiral-insert cleaning mechanism is put forward.It makes use of the hydrodynamic force to change the local flow resistance at the tube outlet periodically to cause velocity fluctuation in the tube,so that the vibratory spiral-insert in the tube scratches the fouling with axial reciprocating movement and the fouling on the inside wall can be removed uniformly.The flow characteristic of the baffle is obtained by experimental study.The computation formula for velocity in the tube with the effect of baffle and the computation method for the baffle opening,which makes the vibration spiral-insert produce an axial reciprocating stroke not less than a pitch,are obtained by theoretical analysis.The test proves that the fouling removal and prevention with the vibrating and reciprocating spiral-insert is more effective.Under the same experimental conditions,the heat transfer coefficient is increased by 60% and 20%,respectively,compared to empty tube and vibration spiral.Moreover,the scaling speed is reduced.

Key words: reciprocating spiral-insert, online fouling removal, hydrodynamic, flow characteristics, scale prevention

摘要： 针对换热管内振动螺旋线清洗技术所存在的防除垢不均匀问题,提出振动往复螺旋清洗机构。利用流体动力周期性改变管口局部流动阻力方式造成管内流速波动,从而引起换热管内振动螺旋对污垢的轴向往复刮擦,达到均匀清除管内壁污垢的目的。通过试验研究得到挡板机构的流量特性曲线,并理论分析推导得到该机构作用下管内流速的计算公式,以及使振动螺旋线产生不小于一个螺距的轴向往复行程时所对应的挡板开度的计算方法。进一步证明了振动往复螺旋的防除垢性能要比单纯的振动螺旋好,相同试验条件下其传热系数比光管和振动螺旋分别提高60%和20%,并延缓结垢速率;而无垢时两者的强化传热效果相当。

关键词: 往复螺旋线, 在线清洗, 流体动力, 流量特性, 防垢性能