24 Jan 2022

Blog Bite 1: Geotube® Dewatering - Getting it Right

By Norhisam Omar


Welcome to our blog space where we share our insights and experiences in civil engineering and geosynthetics. We feature bite-sized articles for quick and easy consumption

                                                                                                                                                                                                                                                                                    

In all engineering challenges, getting the basics right paves the foundation for an effective and efficient solution. Dewatering slurries using TenCate Geotube® dewatering systems can be straightforward if fundamental design principles, proper installation and application fundamentals are applied. Versatile in nature,  Geotube® dewatering systems performs at its optimum in industrial wastewater processing, mining and mineral processing, agriculture, municipal applications and more when the fundamentals are laid out correctly.

Let's explore 6 basic factors over 2 bite-sized articles that will help us get the job done right. 

        

#1. WHAT MAKES A GOOD DESIGN?

An effective Geotube® design starts with a precise assessment (or as accurately possible) of the sludge or slurry that is to be dewatered. This is followed by determining the type and size of Geotube® units required to contain the estimated dewatered solids volume. 

What needs to be looked at?

 

It is worth noting that industry players in industrial wastewater, agriculture, local councils and environmental dredging refer to volume and parts per million when referring to sludge and slurries while the mining industry refers to tons. 

 

#2. TUBE DESIGN and SELECTION

Ideally, Geotube® units should be sized to ensure they can accommodate the maximum delivered slurry volume.

It makes no sense to deposit slurry into a large number of small tubes if a lesser number of large tubes can be used. Unless there are specific circumstances such as space constraints where only small tube units can be accommodated, large units are more efficient and economically the best option.

What are the considerations?

  • Type of fabric
  • Circumference and length
  • Number of fill ports required

How do we achieve and determine the maximum fill heights of the tube?

  • By the type and composition of the slurry
  • Pump delivery rates and
  • Their best configuration within the dewatering pad space

When Geotube® units are proposed by suppliers or contractors, engineers should require calculations to support their submission. 

 

#3. POLYMER DOSING

Polymer dosing enhances the consolidation of fine particles in suspension within the tubes and the discharge of clearer effluent.

Polymer dosing of slurry just before delivery into the Geotube® unit feed pipes is a common requirement. However, not all slurries require dosing, and the cost-benefit of using polymer should be checked and not assumed it is a given requirement.

Additionally, it is important to understand that unlike mechanical plants which uses the agitation process, dewatering with Geotube® units is a passive process which requires less polymer as compared to mechanical plants. Polymer dose rates can be easily verified and adjusted by sampling dosed slurry before the flow enters the tubes.


           

That's all for now. We hope you have enjoyed our first bite.
Check out the next three vital factors of "Getting it Right" in Blog Bite #2

 

If you'd like to know more, feel free to connect with us or email us at info.asia@tencategeo.com 

TenCate Geosynthetics Asia
Send email +603-5192 8568