Anti Crystallization Blocking of Flocking Drainage Pipe Based on Natural Phenomenon




tunnel, pipe plugging by crystallization, flocking drainage pipe, three-dimensional flow field, crystal distribution


Crystalline pipe plugging of the tunnel drainage system was one of the causes of tunnel lining cracking and water leakage. Effective prevention of crystalline pipe plugging of tunnel drainage pipe was very important to ensure the safety and stability of lining structure during tunnel operation. Using the methods of field investigation, indoor model test and numerical simulation, a new flocking anti crystallization blocking technology was proposed. The crystallization law and anti-crystallization efficiency of the flocked drainage pipe at different flow rates, the three-dimensional flow field distribution characteristics and the crystal distribution law of flocking drainage pipe were studied. The results show that the maximum crystallization rate of nonflocked drainage pipe was 1.30 g/d. The maximum stable attachment amount of crystals in flocked drainage pipe was 18.13 g, and the maximum anti crystallization efficiency can reach 80 %. The flocked drainage pipe can preferentially select the villus with the length of 5 mm and 10 mm. The flow velocity at the top of flocked drainage pipe increased by 35 %. Crystals near the water inlet of flocked drainage pipe were mainly distributed on both sides, near the water outlet were mainly distributed in the middle and lower part of the drainage pipe, and were attached to the wall surface of the drainage pipe at the water outlet. Flocked parameters of flocked drainage pipe (flocking material, flocking length, flocking diameter, flocking longitudinal spacing and flocking circumferential spacing, etc.) also need a lot of experimental research, so that the research results can truly solve the practical engineering problems.