The Storm King® Overflow with Swirl-Cleanse™ Screen is an advanced hydrodynamic vortex separator with self-cleansing, non-powered screen designed to effectively capture a wide range of sewer solids.   The system is ideal for satellite treatment at overflow sites and has been shown to save municipalities up to 50% on overall project costs when compared to conventional solutions.

The Storm King^® with Swirl-Cleanse™ is an advanced hydrodynamic vortex separator that incorporates a unique, self-cleansing, non-powered screening device. Designed as the ultimate CSO treatment device, the Storm King^® with Swirl-Cleanse™ does it all, from the screening and removal of gross solids and floatables greater than 6 mm in two directions to the removal of sediments, settleable solids and associated pollutants (eg. TSS, BOD and COD).

The Storm King^® with Swirl-Cleanse™ is ideal for satellite treatment within the collection system. Installing units at the source reduces the need for increasing conveyance capacity and makes this device an economically viable solution.

Applications

• New and retrofit CSO facilities.
• Swirl-Cleanse™ can be retrofit to existing Storm King^® Overflows.
• Remote treatment sites.
• Floatables control for CSOs and collection systems.
• Mixing for disinfection.
• Primary treatment equivalency.

Advantages

• No moving parts or power requirement.
• Self-activating and self-cleansing.
• Low headloss.
• 100% removal of 6mm in 2 direction solids including floatables, gross solids and neutrally buoyant material.
• Removes up to 95% of grit and sediments.
• Small footprint.
• Low capital and life cycle costs.
• Minimal maintenance.

Flow is introduced into the Storm King^® via a tangentially positioned inlet causing a rotational flow path around the dip plate.

As the flow spirals down the wall of the chamber  solids settle out by gravitational and rotational forces (red arrow).

Settleable solids collect in the base as the centre cone directs flow up and around the centre of the shaft into the inside of the dip plate cylinder (dark blue arrow).  The upward flow  rotates at a slower velocity then the outer downward flow.  The resulting ‘shear’ zone scrubs out the finer particles.

The flow then passes down through the Swirl-Cleanse™ screen which captures all floatables and neutrally buoyant material greater than 6 mm.  The air regulated siphon provides an effective backwash mechanism to prevent the screen from blinding.  Screened effluent is discharged into a receiving watercourse (light blue arrow).

The collected screenings and settleable solids are pumped or gravity fed from the base of the unit to the sewage treatment plant (brown arrow).

Typical Design Loading Rate: 25 to 100 l/s/m².

Frequently Asked Questions

Q. What is a Storm King^® Overflow?

A Storm King^® Overflow is a hydrodynamic separator used for removing settleable solids from wastewater. As the flow within the unit is dynamic (moving) the unit requires far less volume than a conventional passive device to obtain the same removal performance. This is because of drag forces set up within the unit due to the flow patterns set up which are themselves dictated by the unit geometry.

Q. Does a Storm King^® Overflow control the flow rate as well as providing solids removal?

No, it doesn’t. Hydro-Brake^® Flow Controls are typically used to control the pass-on flow rate to treatment. If a gravitational system is unobtainable then a pump can be used to control the pass-on flow to treatment as an alternative to the Hydro-Brake^®.

Q. What performance can a hydrodynamic separator achieve?

The performance efficiency of a hydrodynamic separator depends on the physical size of the unit itself (and consequently retention time) and on the settleability of the incoming sewage. Purely neutrally buoyant material cannot be removed by gravitational forces alone. A hydrodynamic separator typically achieves the same removal performance as a primary sedimentation tank in a quarter of the plan area. Higher loading rates can be used when less efficient performance is required, e.g. at a treatment works where grits and silts are desired to be removed but where it is beneficial for finer faecal material to pass forward to further downstream treatment processes. Conversely, chemicals can be added to enhance solids separation.

Q. What dictates the size of a Storm King^® Overflow?

The required diameter of a Storm King^® Overflow is a function of the peak design inflow rate, design removal performance and the available depth. Within defined design limits, unit diameter can be increased to counter-act the effect of limited available depth.