Home - Aeration & Mixing Systems - Aerated Grit Chambers

Spiral-Flow Type Grit Chambers

• Multiple, Isolated Assembly Design
• Variable Airflow Control Flexibility
• All 304/316 SS Modular Assemblies
• Non-clogging, Impact Resistant Tideflex Coarse Bubble Diffusers
• High Grade, Stainless Steel Victaulic Brand Components
• Low Profile Installation

Design Considerations for Aerated Grit Chambers

    Inducing a spiral roll perpendicular through a rectangular chamber utilizes centrifugal froce to remove heavy grit particles from raw wastewater. These grit particles also have attached organic particles that need to be separated from the grit - otherwise they become an odor and vector problem for the containment and storage of removed grit. Generating spiral rolls of the grit particles will result in washing of the organics but the correct roll velocity must be applied for the application specific gravity of the particles (typically 65 mesh [0.20 mm] or larger). Too high of a velocity will result in carry-over or flow-through of the grit particles. Too low of a velocity will result in insufficient washing of the organics from the grit particles. Airflow adjustment methods should be incorporated into the aeration system design for field adjustment and fine tuning of the roll velocities for optimal removal.

    The air diffuser discharge elevation or emittance point should be located above the settling and collection area to prevent re-suspension of particles. Vertical baffles can be utilized to maximize the vertical momentum produced by the rising air curtain and reduce short circuiting of particles across the roll loop.

    Accumulated grit within the collection zone can be removed mechanically with chain and bucket conveyors or screw conveyors. An allowance for periodic grit accumulation and storage should be provided in the collection area during periods when the grit containers are removed, dumped, and replaced as the mechanical conveyors will be shut down during these maintenance periods. These grit levels can also accumulate above the air diffuser level - therefore, non-clogging diffusers should be utilized (no open pore type).

The Tideflex Aeration Assemblies

    The Tideflex Coarse Bubble Diffuser is a heavy duty elastomer duckbill check valve that will prevent the entrance of grit particles into the aeration manifold when the airflow is off and the grit blanket builds above the diffusers. The durable, thick elastomer exterior is excellent at resisting the abrasive effects of grit particles. The Tideflex Aeration Assemblies are modular and easily assembled in the field utilizing Victaulic® Brand rigid couplings and fittings. These assemblies are available in either 304SS or 316SS.

    All support and mounting brackets are provided with the assemblies. Utilizing individual assemblies staggered along the length of the grit chamber, each equipped with an isolation/throttling valve, provides the flexibility for variable airflow adjustment along the length of the grit chamber for field optimization of grit particle washing and removal.

US Patent No. 6,016,839 / 6,193,220 / 6,372,140 / 6,702,263
Canada Patent No. 2,366,252 / 2,385,902; United Kingdom Patent No. 2,326,603