低流速传热管自动清洗强化齿型扭带研究

Research on the Twisted Strip with Teeth to Enhance Self-cleaning Ability of Heat Transfer Tubes at Low Flowing Velocity

现有的塑料扭带不能用于低流速传热设备的自动清洗.为此研制了一种强化自动清洗力矩的斜齿扭带.其原理是在扭带表面上以一定间距排列不对称斜齿,被导向的传热流体对扭带的不对称反作用力形成一个旋转力矩.与现有光滑无齿的自转扭带相比,斜齿型扭带自转清洗力矩增大了277%、传热系数提高了22.8%～30.7%,对于6m长传热管、4管程的设备、0.5m/s流速时的阻力在15000Pa左右,具有广阔的应用前景.

The present smooth twisted strip without teeth can not be used to self-clean away foul for heat exchangers at low flowing velocity.The authors develop a new kind of twisted strip with oblique teeth, which can enhance the force moment of self-cleaning. The principle is that there are dissymmetrical oblique teeth distributed evenly on both surfaces of strip and the heat transfer flowing fluid led by the strip has a dissymmetrical reacting force on the strip, thus the force moment of self-rotation is formed. The overall operation moment is increased by 277% and the heat transfer coefficient is increased by 22.8%～30.7% over the smooth twisted strip. For a heat exchanger of 6m heat transfer tubes and 4 tube circuits, the flowing resistance is about 15 000 Pa at the flowing velocity of 0.5 m/s. Therefore, this new technique has a good application prospect