Dewatering Tubes are designed to replace expensive retention basins and to hasten the dewatering process.
Large tubes manufactured of high strength polyester or polypropylene geotextile fabric are hydraulically filled with a dredge or pump. The tubes can be filled with any material capable of being transported hydraulically. The filled geotextile tube assumes a cross section, which is circular on the edges and flattened on the top.
It is possible to fill the tubes to 70 – 80% of their circular diameter, though 50 – 60% is common. Tubes are filled via injection ports. Smaller pumped water filter bags typically have only one injection point whereas larger dewatering tubes have many more fill ports along the top centerline. These ports are used for both filling and for the relief of excess water.
After bulk dewatering occurs, self weight consolidation and confining pressure of the geotextile tube fabric itself continues the dewatering process. Extremely short dewatering time vs the typical retention pond is a result of this process. Also, the retention of odors, pollutants and very fine particles is a typical result of geotextile tube dewatering. Part of the efficient retention process occurs because of the physical properties of the tube fabric(s) and also from the filter cake that forms on the inside of the fabric sell, thus creating a two stage filter.
Brockton Equipment/ Spilldam’s spiral stitch technique used on it’s high strength geotextile tubes greatly improves the overall strength of the dewatering tube. This is accomplished by reducing the pressure on stitched seams and by increasing the circumference strength through the formation of a reinforcing spiral belt formed by the spiral stitching process.
Standard Dewatering bag: 15 ft x 15 ft with (1) injection port
Custom Dewatering Tubes can be manufactured up to 200 ft long by 30 ft diameter with multiple injection ports.