Pipe jacking is a non-excavation construction technique used to cross sensitive areas such as roads, rivers, and buildings. During the construction process, lubricating slurry (bentonite-based or polymer-based) is injected to reduce friction, which generates wastewater containing solid particles. The solid content in the waste water typically ranges from 5% to 30%, depending on geological conditions such as clay, sand, gravel, or rock layers. The particle size can vary from fine clay particles to gravel larger than 50mm, and in complex geological conditions, large rock pieces may also be present. This waste water needs to be treated to minimize environmental impact.
Given the characteristics of the wastewater, a staged treatment process is required. The typical treatment flow includes: coarse screening shale shaker separation, further solid-liquid separation, and fine filtration/ centrifuge dewatering system which are optional based on the environmental regulations of each country.
Recently, GN Solids Control completed three GNTBM-360 Slurry Separation Plants for an overseas pipe jacking project. These three systems were designed specifically for the same client. The systems include a coarse screening shale shaker system and two-stage solid-liquid separation using desanders and desilter hydrau cyclones. In countries where wastewater discharge is not allowed, additional options like flocculation and dewatering centrifuge systems can be added to meet the regulatory requirements.
Horizontal slurry pumps were used to feed the desander and desilter hydrau cyclones.
The GNTBM-360 Slurry Separation Plant is designed to efficiently treat wastewater generated during pipe jacking operations. The system ensures the effective separation of solid particles from the slurry, allowing for the recycling of the treated water and minimizing the environmental impact of the project. By using advanced equipment such as desanders, desilters, and optional centrifuge systems, the system delivers reliable, high-performance waste treatment solutions for pipe jacking projects.
This tailored slurry separation system from GN Solids Control is an essential solution for ensuring environmental compliance and sustainability in sensitive construction projects that involve slurry-based operations.