The Dynaflo concept is the result of extensive researches carried out since the late '70's on OVER's pilot plant. The flow coming from the computer designed tapered header passes through a first perforated plate into a mixing/equalizing chamber that optimizes the stock pressure and fiber suspension just before the turbulence generator, which is the core of the DYNAFLO concept: the stainless steel Dynaflo tubes present a conical cross section, transitioning gradually from round to rectangular.
After a high acceleration at the inlet orifice, a gradual diffusion of the stock flow along the Dynaflo tubes weakens the large-scale turbulence, while sustaining the small-scale turbulence, thanks to the many boundary layers generated by the friction with the tube walls. Each tubes row has an optimum velocity range: by multiplying the tubes row, a broad range of flow rates can be accommodated, giving this headbox design the greatest adaptability to all operating conditions. The configuration of the tubes row ensures a negligible residual wake signature on the stock jet. This concept, after 30 years from its birth, still gives one of the best sheet formation made on today's hydraulic headboxes.
Dynaflo-FL: Headbox with Lamellas
The DYNAFLO-FL is available also in a multilayer layout, which permits the use of two or three different stock characteristics and quality to produce multilayer paper with one forming section.
The edge flow control is another important optional for this headbox, indeed a special system is designed to modify locally the flow on the edges, from 60% up to 160% of the nominal flow, thus permitting an optimal fibre distribution on the entire paper width.
The Dynaflo construction, entirely in solid stainless steel, with thorough finish and electropolishing of all the surfaces in contact with the stock, guarantees a safe and trouble-free operations for many years.
The different sizes of the Dynaflo-F cover a range from 2 to 18 m3/m.