GN Provides Green Way for Hydro Excavation Companies to Save Green

HOUSTON, Sept. 1, 2021 /PRNewswire-PRWeb/ -- Compared to traditional digging and excavating, the Hydrovac Excavation process is a much faster, safer and more environment friendly digging process as it uses pressurized injecting water to dig out the aggregates, sands, soils. Hydrovac excavation works by injecting high pressure water into the ground through a hose connected with a vacuum unit. When the liquefying soil becomes a mixed slurry, then it is vacuumed out by a powerful pumping system into a hydrovac truck.

Hydrovac excavation minimizes disruptions and possible damages to nearby facilities or infrastructures. Any soil type even from frozen ground, hydrovac excavation can perform successfully.

More and more contractors are using hydrovac excavation, but how to effectively treat those hydrovac mixed slurry? Most hydrovac waste is dumped into a legal mud pit, where hydrovac contractors pay a high rate to awaste management company to dispose of the waste. Furthermore, trucks must drive long miles which is time consuming and costly. Suffered by increasing rate, contractors are realizing the importance of treating the spoils themselves instead of handle them to liquid waste treating company.

Canada and US have the world largest hydroexcavation trucks; GN Solids Control has been providing new technology hydrovac slurry dewatering systems to many hydroexcavation crews. With different cities have strict environment protection rules, these customized slurry dewatering system becomes more and more popular. A dewatering system can treat from 10 hydrovac truck loads to 100 truck loads every day. Waste turns into treasure，and reduces the volume of the waste discharged to the nature largely.

A hydrovac truck can carry slurry with max. 60-70% solids, by using hydrovac waste slurry dewatering system, it can be recovered up to 85% materials which are all sell-able aggregates, sands and silts, and water can be reused to flush the hydrovac truck or recycle in the whole treating system.

This dewatering system is a proven green way to save green. When hydrovac trucks come with waste, they climbed in a inclined ramp where two trucks can drump at the same time to a big catch hopper waiting in a line.

Open wire mesh fixed on the top of the hopper to hold the big stones or strays etc falling off and through the automatic gate valve. High pressure flushing nozzles around the hopper to keep the hopper from blocking.

GN Solids Control has utilized many technologies in oil and gas drilling mud separating, mining slurry and HDD slurry treating process. Slurry falls into coarse shaker first, which is equipped with 10 or 12 pcs long screen panels to allow the slurry have enough time to stay above. All big particles, like gravels, pebbles or aggregates are removed, then transferred by a belt conveyor.

A VFD submersible pump feed the slurry fell through the coarse shaker into a double deck fine shaker. By using large mesh screens on the upper deck and small mesh ones on the bottom deck, fine shaker treat the slurry twice and remove sands out.

Desilter uses multiple 4 inch cyclones to treat the liquid from fine shaker. Feed by another submersible pump, destiler can recover most of the solids larger than 25 microns. A ViST (vacuum screen) unit can be provided as an optional reinforce separation unit, to recover over 10-15% solids.

Many elaborate works have been done to keep this dewatering systems running smoothly and continuously. As the key treating equipment, decanter centrifuge runs at a high rotating speed to eliminate solids larger than 2-5 microns. Centrifuge bowl and screw propeller both rotate at the same direction but with a differential speed, due to the density difference, solids are forced to the outer inside ring of the bowl and pushed out from the solids discharge port where tungsten carbide inserts are used to protect them from long time wearing, and liquid leave in the center before thrusting to the drain outlet. To have a better treating performance, a chemical dosing unit may be used.

To meet hydroexcavation contractors, this system should be designed in a compact modular structure, easy and fast to connect and relocate. Working parameters also need to be changed easily in a centralized control system, and alarms are monitored from HMI screen. Here is a hydrovac slurry dewatering video.

Overall, GN new technology hydrovac slurry treatment systems empower greater control of the waste, providing a more sustainable approach to processing waste slurry and reduce disposal costs.

Media Contact

Thomas Meng, GN Solids Control, +1 (713) 878-0880, [email protected]

Bruce Dong, GN Separation and Conveying, +86-137-3150-0403, [email protected]

Twitter, Facebook

SOURCE GN Solids Control