Overview 

The Grit Snail® is a quiescent dewatering belt escalator that captures and dewaters the fine grit output from a HeadCell®, SlurryCup™ or TeaCup® grit removal system. Providing solids output with low water content, the Grit Snail® reduces solids handling and landfill costs.

Designed to handle very fine grit, the slow-moving belt pulls solids from clarifier water without agitating the water, thereby retaining even very fine particles. The belt operates within an abrasion-resistant belt housing and incorporates components with no metal-to-metal contact, in order to reduce wear. The variable frequency drive adjusts belt speed to match changing grit loads and the torque-limiting clutch protects the drive system and belt from mechanical overload.

Municipal wastewater plants with combined sewers or industrial loads require greater dewatering capacity; different sizes of Grit Snail® units or multiple Grit Snail® units can be configured to match any grit load.

Only Grit Snail®

  • Separates the grit washing and dewatering process to reduce turbulence
  • Uses a quiescent dewatering process in order to retain even the finest grit particles

Applications

  • Non-turbulent dewatering for clean, fine grit output from a HeadCell®, SlurryCup™ or TeaCup® system 

Watch a brief video demonstrating the Grit Snail®  here. Download the Grit Snail® brochure here.

 

Designed for

Coarse particles

Fine particles

Very fine particles

Benefits

Retain more, finer grit

Many conventional grit removal systems will combine washing and dewatering into a single process. Washing is a turbulent process, however, and dewatering should be performed under still conditions; combing these processes is why many types of systems fail to retain fine grit. The Grit Snail® is a quiescent system with a slow-moving belt that eliminates this kind of turbulence, meaning that it retains more, finer particles.

Reduce operating costs

When matched with a Hydro International separation and/or washing system such as the HeadCell®, SlurryCup™ or TeaCup®, the Grit Snail® retains fine grit and outputs material with very low volatile solids or residual moisture, cutting odor and making the output easier to handle and dispose of. Your treatment plant is the best way to treat water and organics - avoid paying the expense of landfilling water and organic content. 

How it works
  1. Grit-Snail-Cutaway-How-It-WorksGrit and fine abrasives are discharged by a grit washing unit into the Grit Snail® clarifier, where they settle onto the slow-moving stepped cleats.

  2. The captured solids are gently lifted out of the clarifier at between 1 and 5 feet per minute.

  3. Degritted water flows out of the clarifier via an overflow weir.

  4. Dewatering begins as the grit and fine abrasives are quiescently raised from the clarifier pool to retain fine grit.

  5. The dewatered abrasives are carried to the top of the Grit Snail®, where they are discharged into a disposal container for landfilling.

The slow-moving cleated belt gently escalates the grit from the clarifier, retaining fine grit, unlike turbulent dewatering systems which reintroduce captured grit back into the plant. The Grit Snail® is designed for durability and ease of maintenance, resulting in a very long product life and trouble-free operation.

 

Technical information

Performance characteristics            

  • Removes 95% of all grit 75 micron and larger at the design flow rate when used with a Hydro International washing system
  • Outputs 60% total solids and less than 15% volatile solids when used with a SlurryCup™ or TeaCup®

Capacity

  • Dewatering capacity from 1-10 yd3/hour of grit 

Size

  • Clarifier sizes from 48" to 96" square 
  • Belt widths range from 6" to 57.5" 

Design notes

  • 304 stainless steel construction standard; 316 stainless steel available 
  • NEMA 4X valves and stainless steel control panel
  • Variable frequency drive
  • Belt rinse system
  • Belt housing is lined with abrasion resistant urethane for long product life