Valve for Bentonite Slurry Handling System

What is Bentonite?

Bentonite is absorbent aluminium phyllosilicate clay. The main uses of bentonite are in drilling mud and as a binder, purifier, absorbent, and carrier for fertilizers or pesticides.

Bentonite slurry is one of the most common excavation fluids used in constructing a diaphragm wall. Bentonite clay (in powder form) and water are combined in a colloidal mixer and clay particles bond to each other and set to form a gel when left to stand for a period of time.

An original equipment manufacturer have been installing Pinch Valves onto their slurry handling equipment for many years.

The bentonite slurry mixer is designed exclusively for producing and temporarily storing a flowable slurry containing suspended solid material, using water and various powdered solid materials.

The tank is intended exclusively for holding and intermediate storage of a flowable, water-based slurry containing suspended solid material.

Pinch Valve used within this application: VF125.03X.31.30LA

VF model, DN125, air operated, aluminium body, aluminium flanges PN10/16 with mild steel bushings, natural rubber sleeve.

Description of the mixing process

The batch mixing system is driven electrically. Water is fed into the running mixer from the water tank. The solid materials are fed into the mixer via the solid material filler necks using screw conveyors. The mixer stands on a weighing device. Feeding of the solid materials and water is controlled via weight measurement.

On completion of all dosing procedures, the fed components are mixed for the specified mixing time as entered. The mixture is continuously internally recirculation pumped during dosing of the solid material and during the mixing procedure. After this, the slurry is then pumped into the slurry tank.

The bentonite slurry is temporarily stored in the slurry tank, where an agitator counteracts sedimentation and removes solid deposits. The slurry can be supplied through the shut-off valve at the slurry outlet to a connected pipe or hose.

How the Pinch Valves for bentonite slurry aid with this application

The AKO Pinch Valves installed on this equipment are for use mainly in piling. The slurry is used to prevent the sides collapsing into the excavation while it is being dug, until it is filled with concrete. One Pinch Valve for bentonite slurry allows it to circulate in the mixer, while the other allows the slurry out into the holding tank once it is mixed.

After many years of this slurry handling equipment being exported to companies around the world, and working successfully with Pinch Valves used in the slurry line for draining, the OEM continue to order more Pinch Valves when building more of the same equipment.

The 100% full bore, no dead spots and the Pinch Valve’s self cleaning rubber sleeve, are just some of the advantages which allow this system to perform smoothly. The fact that the rubber sleeve opens and closes in the same elliptical shape every time means that it lasts longer. In turn, this also means less maintenance and less cost.