Flexkleen® Nozzles

FlexKleen® hydraulic nozzles are suitable for both heavy industrial waste applications and light-duty water treatment. They can be used in any type of pressure or gravity filter, including those with steel or concrete underdrains.
  • Suitable for industrial waste applications, municipal water treatment and wastewater treatment
  • Can be used with sand, anthracite and granular activated carbon media

Headloss in filter media systems is unavoidable. Traditional methods of controlling headloss are prone to clogging, jetting or uneven distribution of backwash, which leads to a loss of filter material and requires frequent cleaning intervals. EWT™ FlexKleen® Mark III nozzles are engineered to maintain clear orifice openings, minimizing the headloss necessary for process requirements.

The simple, yet effective design is easy to install. Current nozzles easily replace older models. The improved FlexKleen nozzle heads are injection molded from strong, chemically resistant ABS plastic, suitable for use in single or dual filters, although other plastics are available for special applications. The FlexKleen® Mark III nozzle has NSF 61 approval.

  • The nozzles are designed to provide the correct headloss
  • Easily replaces previous nozzles
  • Durable materials and design
  • One nozzle, many applications
  • Incorporates a tail piece for air distribution during the air scour step

EWT™ FlexKleen® nozzles are designed to carry out four basic functions.

Elimination of Internal Pressure Balanced Feed Distributors – The pressure drop created by the nozzle (up to 20-psi) balances the collection of filtrate during the filtration cycle, eliminating the need for a header and lateral type filter inlet distributor.

Elimination of Gravel Layers – Vertical ribs in the nozzle head prevent filter media from passing into the plenum chamber. The slots widen towards the inside, presenting a sharp outer edge to the media. This allows the placement of sand directly onto the nozzles, eliminating gravel layers and their associated problems.

Uniform Distribution of Air Scour – Backwash air is metered evenly into all nozzle heads through air tubes. Multiple orifice sizes and elevations are optimized for low, medium or high-rate air scour requirements. A baffle ring extending down from inside the top of the nozzle directs the scouring force of the air in a radical pattern from each nozzle.

Uniform Distribution of Water Distribution – The pressure drop created in the nozzles ensure water backwashing is evenly distributed through the filter media. Water is discharged radially at a 15° angle above the filter floor. An internal cone directs and stabilizes flow inside the nozzle head.

Are the nozzles tapered or straight?

The nozzle openings are tapered, larger to smaller from the inside out. The smaller opening on the exterior ensures that filter media particles are held on the face of the nozzle and do not penetrate the opening. The increased opening downstream of the nozzle ensures that any particles small enough to pass through the opening will pass on through the nozzle and not clog the openings.

What is the headloss during backwash?

Headloss is typically 20 gpm/sf. The backwash rate is 24 inches of water column. Headloss curves identifying the headloss during a variety of flow rates are available when engineering design of a new filter project is complete.

What purpose does the tail piece serve?

The tail piece has a series of orifice holes space along the tube to ensure that the air for scouring filter media is distributed uniformly into the nozzle and filter bed.

Are tail pieces adjustable?

Yes. There is an Ovivo supplied tool that allows the contractor to adjust the orifice height during installation, ensuring uniform air distribution, even if the underdrain panels are not installed level.

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