ESG Waterwise Technology Ltd

ESG Waterwise Technology Ltd

- Centrifugal System


How it works: Driven by the inlet pressure, the water or liquid with particles enters the top chamber at a tangent causing a rotation, and accelerates through the tangential slots/holes in the top section of the separator, down into the centre section of the separator, causing rapid rotation within the centre sector.

The rotation of the liquid forms a vortex in the centre of the separator. The centrifugal action forces the separation of heavy particles from the water. The separated particles accumulate in the bottom collection chamber where they are periodically purged. The cleaned water flows through the central vortex from the top of the cyclone.

The benefits

  • Continuous uninterrupted dirt seperation: No backwashing or cleaning cycle
  • Low Head loss: Fixed flow and pressure loss characteristics allow the unit to be easily integrated into the system at the design stage
  • Filters to less than 20 micron: Cyclones will filter down to less than 20 microns on a continuously recircluated system.
  • No filter or media: Removes the need to change filter elements or filter media
  • No downtime requirements: The unit is designed to operate continuously with no routine shutdowns. Purging of system performed during full operation
  • Small, compact: Easy to install
  • Does not harbour bacteria: No filter media or dead legs for bacteria such as Legionella to live
  • Available in a large range of sizes - 0.7 - 2,700m3/hr: Units to suit all applications
  • Available in a range of materials: Carbon Steel 304 and 316 Stainless Steel
  • Anti corrosion / abrasion specialised coatings: ATD Series allows application of specialised coatings such as Rilsan.

Cooling towers act as air scrubbers, collecting dust and debris from the air and water used in their normal operation. In built-up city environments or industrial locations, airborne typical dust levels of 15 to 200 mg/m3 are typical. A 2000 kW heat rejection cooling tower would accumulate 16 kg per day of solids at only 25% duty load.

This level of dirt loading, unless removed, would cause progressive fouling of heat exchangers, leading to fouling factors of 0.0001 or above. For heat exchangers designed with typical fouling factors of 0.00004, this would reduce heat exchange performance by 20 to 25%, increasing energy consumption by 8 to 12%.

The STC Series of cyclone filtration units are designed for sidestream filtration on cooling towers, evaporative condensers and open circuit systems, for removal of suspended solids and sludge.

A sidestream flow is drawn from the cooling tower sump and cleaned continuously by the filter before being returned to the sump. Suspended solids collected in the filter are purged to drain automatically using a timer controlled auto purge valve.

Filtration of cooling water reduces chemical treatment requirements of the cooling system by removing suspended solids, which harbour and encourage biological growth.

The problem

Dirt, debris, swarf, welding splatter and mill-scale are all incorporated into closed circuit water systems during construction. The complexity of pipework design in modern buildings means that it is often impossible to remove all this contamination by pre-commission cleaning and flushing.

Suspended solids and sludge continue to accumulate in systems during their working life due to corrosion, hard water, system modification etc. Corrosion of mild steel typically produces sediment volumes of 10 to 100 times the volume of the original metal removed.

Heating systems typically make up at 1.5 to 2.5% of the system volume per week. For a 10,000 litre volume system in a hard water area this will lead to more than 3 kg of solids per year accumulating in the system.

Closed circuit systems rarely fail due to corrosion and leakage most failures are due to accumulation of sediment causing blockages, poor heat distribution or dissipation, boiler failure and valve failure.

Typical problems caused by dirt and debris

New buildings

  • Difficulty in establishing and maintaining system balanceValves jamming and blocking
  • Noise
  • Pump seal failure

Existing buildings

  • Poor heat distribution
  • Blockages & lack of flow
  • Pump seal failure
  • Control valve failure
  • Noise
  • Boiler failure


  • Continuous filtration with no backwashing or flushing required.
  • Closed recovery system provides zero water loss, saving water chemicals and energy.
  • Suitable for a wide range of temperatures and pressures, including high temperature hot water and chilled water systems.
  • Easily installed to existing systems.
  • Independent of system operation and flow.

Compact packaged system for closed circuit systems

Compact sized unit complete with pump and controls provides a high flow filtration system with minimal space requirement.

The units are skid mounted which means they are readily manoeuvred into position with no site assembly or lifting equipment required.


The CSF Series units will remove metal oxides, precipitated hardness salts and other separable solids down to less than 20 micron on continuous re-circulation.

Closed Recovery Systems (CRS Units)

Used in conjunction with our CSF range of cyclone filtration systems, these units collect the filtered dirt from the filter purge discharge allowing purge fluid to be returned to the system thereby eliminating any water or fluid loss from the system. The filtered dirt is collected in re-usable fabric bags for disposal.

CRS closed recovery systems are recommended for systems where fluid loss from filter purge needs to be avoided such as: -

  • Brine systems
  • Glycol systems
  • Thermal fluid systems
  • Chemically treated systems
  • Medium and High Temperature hot water systems

Benefits of CRS units

  • Saves time
  • Saves energy
  • Saves chemicals
  • Saves money

Customer reviews

No reviews were found for Cobra Cyclones - Centrifugal System. Be the first to review!