The Next Generation Density Current Baffle
Stamford Baffle 2.0® offers an unprecedented improvement in clarifier performance in terms of reduced TSS and increased hydraulic capacity. Computer modeling predictions developed during NEFCO’s CFD study indicated that Stamford Baffle 2.0® would reduce effluent solids by 30%
to 50% over the original Stamford Baffle, as shown in the figure below. Actual field results at a recent installation confirmed that Stamford Baffle 2.0® reduced total suspended solids by nearly 80% and enabled that treatment plant to achieve a 35% increase in overall hydraulic capacity.
Stamford Baffle 2.0® features a 30° inclination angle as measured down from the horizontal and a greater horizontal projection from the clarifier wall, calculated as a function of the clarifier diameter. The shallow angle increases the baffle-to-blanket distance and deflects the density currents on a more horizontal trajectory (without increasing solids buildup on the baffle), while the increased projection of the baffle intercepts a greater volume of solids rising toward the launder.
Stamford Baffle 2.0® retains all of the features that made the
original NEFCO Stamford Baffle the best selling baffle system in the
world.
Stamford Baffle 2.0® is comprised of individual baffle sections or "modules". Each module combines the baffle panel, the baffle bracket, the vents and the mounting and stiffening flanges in a one-piece molded fiberglass unit eight feet long that offers a number of advantages:
- The one-piece, modular design cuts installation time in half. The
individual baffle modules align easily and require fewer fasteners.
- The integrally molded bracket and other reinforcements means one bracket per panel.
Some baffles require two brackets per panel and others attempt to
cantilever their baffle from the tank wall without benefit of
support brackets.
- The vents are
molded into the baffle's horizontal mounting flange.
All other baffles have holes cut in the laminate and sealed - a
secondary operation that creates the possibility of water intrusion
and de-lamination.
The baffle modules are attached to the tank wall or the corner of the inboard launder with stainless steel anchors. Mounting holes are factory drilled and sealed. Adjacent modules fasten together at a molded recess that forms a ship-lapped joint. Sections of the baffle may be cut as required to fit around piping and other obstructions. The baffle's laminate features a tough, corrosion-resistant and uv-suppressed fiberglass resin specifically formulated for use in industrial and municipal waste treatment applications.
The Stamford Baffle 2.0® Baffle System is readily converted to NEFCO’s new Dual Surface Baffle. This dual surface configuration is designed for larger clarifiers operating at very high flows, including combined sewer configurations.
Patent Applied For
NEFCO's Dual Surface Density Current Baffle was developed through the company’s CFD Baffle Study. This baffle is designed for larger clarifiers operating at very high flow, and has the potential to reduce effluent solids by as much as 80%.
As a part of its CFD Baffle Design Study, NEFCO engineers began to explore alternative baffle configurations that might further improve baffle performance. These new configurations were inspired by the predicted flow patterns of the density currents around the baffle.
The study showed that:
- The Dual Surface Baffle has the potential to reduce clarifier effluent solids to a far greater extent than the Stamford Density Current Baffle.
- The performance of this baffle improves as a function of clarifier size.
- The performance of this baffle improves with increased effluent flow.
The Dual Surface Baffle has a wedge-shaped configuration with identical upper and lower surfaces. The upper surface is identical to the Stamford Baffle 2.0® design, using the 30° inclination angle and the same algorithm to determine the baffle’s horizontal projection based on clarifier diameter. The lower surface is a mirror image of the upper and is inclined back to the clarifier wall. The configuration of the baffle allows the lower portion to be retrofitted to any existing NEFCO Stamford Baffle, upgrading it to the Dual Surface configuration.
The basic design of the Dual Surface Baffle is shown below. The baffle is wedge-shaped, with identical upper and lower surfaces that fasten to the tank wall. The inclination angle and horizontal projection of the Dual Surface Baffle are identical to those of the Stamford Baffle 2.0®. The upper surface of the baffle includes the integrally molded vents of Stamford Baffle 2.0®.
The Dual Surface Baffle is comprised of individual upper and lower baffle sections or "modules." Each module combines the baffle panel, the baffle bracket (upper panel only), the vents and the mounting and stiffening flanges in a one-piece molded fiberglass unit eight feet long. The vents in the upper section are the standard, integrally molded vents found in Stamford Baffle 2.0®. The lower section features large rectangular openings formed as a part of the baffle mounting flanges. These openings serve to inhibit solids from collecting inside the baffle, and provide a convenient means of cleaning the baffle periodically, if necessary.
The Dual Surface Baffle modules are attached to the tank wall with stainless steel anchors. This baffle is not intended for use in clarifiers with inboard launders. Mounting holes are factory drilled and sealed. Adjacent modules fasten together at a molded recess that forms a ship-lapped joint. Sections of the baffle may be cut as required to fit around piping and other obstructions. The baffle's laminate features a tough, corrosion-resistant and uv-suppressed fiberglass resin specifically formulated for use in industrial and municipal waste treatment applications.
Patent Nos: 7556157 & 7726494
Photos
The Stamford Baffle 2.0®
