Model Tests for Anti-Crystallization Measures of Highway Tunnel Drainage Pipe

Abstract:

In order to explore the crystallization behavior and differences in the drainage pipe， this paper， in combination with field research and the crystallization blockage theory conducted physical model tests to explore the crystallization law in the drainage pipe of six drainage pipe materials， nano-coating and silica phosphorus crystal scale inhibitor. The results show that the flow rate is the dominating factor in pipe improvement， At a small flow rate， there is little difference in improvement between different materials and nano-coating， thus the crystallization amount are very large. When it comes to the high flow rate， the crystallization of each condition is pretty low， and the order of crystallization amount from small to large is nano-coating， polytetrafluoroethylene （PTFE）， polyethylene （PE）， polypropylene （PPR）， double-wall corrugated pipe （HDPE）， polyvinyl chloride （PVC）， steel pipe and silicon phosphorus crystal. The material with a low surface energy and a large contact angle has a certain preventive effect on crystallization under the high flow rate condition. Gravity deposition dominates the crystalline material under the low flow rate condition and promotes heterogeneous nucleation， while deposition under the high flow rate condition is closely related to the material properties of the pipe， and the exfoliation effect is absolutely dominant.

Key words:tunnel engineering;drainage pipe material;flow rate;drainage pipe deposition mechanism