WAUKESHA, Wis., Jan. 17, 2003 – USFilter recently received a key patent for its DualAir® diffuser assembly and hollow rivet attachment.  U.S. Patent No. 6,464,211, issued Oct. 15, 2002, describes an innovative design for attaching 9-in. membrane disc diffusers to an air distribution pipe.

Developed by USFilter’s Envirex Products, the DualAir® fine-bubble diffuser system is used to aerate wastewater inside a treatment tank.  The system consists of two diffuser bases connected by a curved saddle that fits over conventional PVC air distribution piping.  This allows twice as many saddles to be mounted to a given length of pipe, compared to conventional single-pod diffuser designs.

The DualAir® diffuser saddle is secured to the aeration pipe by a pair of hollow core rivets with internal threads.  Each hollow rivet serves as a regulating orifice, helping to ensure uniform air distribution to all of the diffusers on the distribution pipe network.

Conventional diffusers are permanently glued to the air distribution pipes, and are typically attached at a single, small area at the top of the pipe.  For this reason, the joints are more likely to break when excessive torque is applied to loosen a threaded retaining ring during membrane replacement, especially in cold weather.

 With the DualAir® fine-bubble diffuser system, the two-rivet connection between the diffuser assembly and the distribution pipe grips the pipe over a large area, much like an “eagle claw,” reducing the possibility of damage when torque is applied during maintenance.  

This increased flexibility in mounting the diffuser assembly to the distribution pipe network also simplifies the task of mounting numerous diffuser assemblies along the length of a distribution pipe when submerged in a treatment tank, and further minimizes the cost associated with installing, cleaning and/or replacing the diffuser assembly.