White Technologies, Inc.

We Make Cake Outta Your Milkshake


Choosing the Vacuum Sludge Dewatering Bed

When you need to manage sludge, it's important to make sure you're taking full advantage of the best system for the job. At White Technologies, Inc., we give clients access to the innovative vacuum sludge dewatering bed. This improvement over traditional methods helps you avoid pitfalls like:

  • 3- to 4-Day Waits Between Operating Cycles

  • Large Required Areas (Move Space) to Process Solids Load

  • Low 8-10% Solid Production

  • Risk of Plate Damage

  • Periodic Removal of Plates to Clean Solids Buildup

  • Climate Dependency

  • Labor-Intensive Cake Removal

  • Loss of Sand During Cake Removal

  • Compacted and Plugged Sand

  • Undesirable Public Appearance and Odor

  • Limited Value for Large Plants

Instead, you get superior performance driven by smart design and an emphasis on simplicity. Some advantages to utilizing our approach include:

  • Results Compliant with the Paint Filter Test

  • A Complete Cycle That Typically Takes Less Than 24 Hours

  • Less Land Space Use

  • Few Moving Parts, Low Maintenance

  • Overall Lower Operating Costs

Choosing the Vacuum Sludge Dewatering Bed

  • Sludge is spread on the media plates through sludge inlet line discharge ports controlled via valves. Prior to this discharge, polymer is injected into the sludge and rapidly mixed at the polymer/sludge blender. Gravity dewatering begins as the bed is filling. The clear liquid, separated from the flocculated solids, flows down through the porous media and through the support plenum as it exits the bed structure.

  • After the bed is filled to the maximum liquid level, the conditioned sludge feed is shut off. The vacuum pump starts, creating a vacuum in the plenum and media and causing a uniform pressure on top of the cake. Motorized filtrate drain valves, automatically controlled by level sensors, discharge the filtrate from the plenum of the VSDB. Typically, filtrate-suspended solids are less than 30 mg/l, indicating very high solids capture in the dewatered sludge.

  • As the sludge continues to consolidate and shrink, the resulting cake will start to crack. This will continue until the bed is uniformly cracked, and the vacuum gradually lost. As the plenum area loses vacuum, the pumps shut down.

  • The stop-gates can now be removed to allow a front-end loader access to the bed to remove the dewatered sludge. The surface is then washed down with high-pressure, low-volume water. This wash-down water is discharged to the sewer or directed back to the head of the plant.

  • Following cleaning, the stop-gates are placed back into position, and the facility is ready for another dewatering cycle. A complete dewatering cycle is typically 24 hours. Click here for in-depth information about our biosolid study, which we use to inform our processes.