Research and application of the integrated system for small-diameter reverse circulation dredging equipment

Abstract:

During the 14th Five-Year Plan period， a large number of small-diameter PVC groundwater monitoring wells have been deployed nationwide to monitor the environmental quality of groundwater in unconfined aquifers， as part of efforts targeting the "dual-source" inventory and groundwater environmental monitoring. The bottoms and inner walls of these groundwater monitoring wells often become clogged due to sediment and impurity deposition. This paper focuses on the challenges of maintaining and clearing silt in small-diameter groundwater monitoring wells. A portable equipment integrated with air lift reverse circulation dredging technology was designed and developed， and the system composition and technical principles of the portable dredging equipment were elaborated. Simulation analysis results based on a simplified Euler''s three-phase flow model and statistical data on the dredging effectiveness of the equipment system for monitoring wells of different depths and various types of sediment indicated that the developed system significantly improves dredging efficiency for wells of varying depths. The sedimentation rate in monitoring wells is significantly correlated with the properties of soil particles in the groundwater. The predicted outcomes from numerical simulations are generally consistent with the measured data from engineering practices in terms of overall trends， with actual engineering results outperforming the predictions. This integrated equipment system addresses the challenges of maintaining and dredging small-diameter groundwater monitoring wells in the ecological and environmental sector， significantly extends the service life of monitoring wells， and delivers notable economic benefits.