InvisiHead Seawater Intake-Outfall Systems

Seawater Intake System Brochure

The InvisiHead is an omni-directional intake system fitted to the upstream end of the intake system pipeline located at a certain depth some distance into the sea from the shoreline. It provides super slow approach velocity that makes the intake system “Hydraulically Invisible” to suspended matter therefore it does not draw in debris that could otherwise cause clogging of the water intake. The low entrance velocity leads to lower pipeline head losses. Inferior designs of the upstream inlet of intake pipelines can lead to creating high negative pressure at and around the inlet (Intake Mouth), which will result in the suction of sand, fish, seaweed and other debris.

 
Functions of the InvisiHead

The InvisiHead works as a water intake system to address problems associated with:

• Sea Sand & Grass
• Zebra Mussel
• Fish & Larvae
• Trash & Debris

The InvisiHead works also as an offshore submarine outfall system providing many benefits:

• It diffuses the effluent in such a manner that does not allow it to rise up to the surface and be waved back to shore
• The dispersed effluent mixes with the ambient deep water and in a short time it assumes physical and chemical properties similar to those of the surrounding seawater thus the effluent remains below the surface
• The InvisiHead works as an efficient heat transfer system when used as a power plant cooling water outfall

 
Applications of the InvisiHead

The InvisiHead has many applications as a water intake and outfall; it could be used for various industrial processes such as:

• Thermal power plants
• Water treatment plants
• Wastewater treatment plants
• Water desalination plants
• Pulp and paper plants
• Petrochemical plants

 The InvisiHead

 
The InvisiHead Seawater Intake velocity cap – a patented omni directional intake head system – adds to the performance of the offshore system. It is fitted to the upstream end of seawater intake system pipelines located some distance into the sea from the shoreline. Entrance velocity is lower than  0.091 m/s (< 0.3 fps).  The approach velocity is extremely slow <0.002 m/s (< 0.007 fps) at 5 meters away – the InvisiHead intake head becomes hydraulically invisible to suspended matter. In other words, the intake head does not act as a sink point and therefore does not suck in debris. Floor sand, silt, and tiny larvae (< 20 umg) remain undisturbed by the lower flow streamlines taking off from the sea floor. The super slow entrance velocities also lead to lower head losses and lower level draw down at the pump intake basin; the head loss at the InvisiHead is at a negligibly low 0.0017 mm.

The InvisiHead entrance section is hydraulically fine-tuned in lab to optimize system hydraulics. The entrance dimensions are not arbitrarily selected but hydraulically calculated in a multi-dimensional approach. Each dimension is a function of the steady flow velocity. Eddies through this approach are totally eliminated.

The InvisiHead System is supplied with a built-in anti biofouling dispensing system to be connected with an onshore disinfectant source through HDPE or PVC hose. The system is designed so that 100% of the disinfectant dispensed remains in the water flowing into the intake pipeline and none flows outside of the system.

The InvisiHead is a key component in the intake system.

• Low approach velocity 0.0027 m/s (0.009 fps) max. at 5 meters away
• Low entrance velocity 0.091 m/s (0.3 fps) max
• Negligible head loss at 0.17 mm
• Maximizes pumping efficiency
• Component form for assembly at site
• Variable flow phases to promote head loss reduction that results in:
  – smaller pipelines
  – shallower intake basin
  – less debris inflow
  – the elimination of the need for backwash
  – further reduce debris inflow
  – perform self-cleansing
• Stainless steel construction
• Built-in anti biofouling chemical dispensing system
• No screens are used at any stage of the InvisiHead
• Adaptability for use in industrial effluent outlets and outfalls
• Can be retrofitted to existing systems
• Immune to oil spills
• Low initial cost
• Lower O&M costs
• Less debris present in the cooling water including sand hence lower potential for erosion of heat exchanger tubes and pump vanes
• Drastic reduction of chemical consumption including chlorine due to the oxidizable material load reduction
• Drastic reduction of entrained air in the cooling water and less oxygen would be present in the water, hence lower potential for corrosion and lower frequency for air evacuation process
• Marine life preservation
• Maintenance costs are much lower, no traveling or fixed screens are included, and therefore, no longer deferential pressure activation mechanism is required, no backwash at all
• Higher cooling efficiency since the water brought in from deep locations is cooler than the beach water
• Storms have no negative effect on the system
• The standard outfall channel is replaced by a much more efficient diffusing system that ensures adequate mixing and efficient heat dispersion. The heat plume does not reach the surface and it is confined to the area close to the point source eliminating any adverse effects on the environment
• Robust and stable under all weather conditions
• Especially fit for use in hurricane regions
• Meets and exceeds world-wide environmental requirements

The InvisiHead Seawater Intake velocity cap is the ultimate in intake head systems.