By Michael P. Mormino and Douglas M. Horner
‘Go green’ efforts have recently become a major public initiative as a ‘new’ idea. Yet many water treatment dealers have experienced firsthand the negative impact water contamination has had on the environment for years. Their professional insights and expertise have led many to be proactive in demanding green water treatment solutions that will help the environment and in turn, benefit their customers.
Manufacturers and distributors have been responsive to these requests, engineering a multitude of products, systems and techniques that purport to reduce environmental impact and lower energy consumption.
One of the most efficient green products is the full plate distributor vessel, currently the only one of its kind in the industry for residential and light commercial applications. It achieves optimal backwashing and cleaning action of medias by utilizing a high-flow, lift-and-bed fluidization that creates a scrubbing action and distributes water throughout the bed.
A brief history
The water treatment industry in the early 1950s almost exclusively utilized steel pressure vessels to build their systems. In 1954, Structural Fibers was incorporated and Jim Horner began development work on fiberglass reinforced products (FRPs). His effort eventually found application in the water treatment industry as seamless, fiberglass-reinforced pressure vessels, which signaled the end of the residential steel vessel market. Culligan was the last high-volume steel manufacturer, well known for their triple-hull tanks.
By the late ‘60s and early ‘70s, the FRP-style vessels dominated the world residential water treatment market. Other companies, such as Apex and Park International, joined the field of manufacturers. During this time, engineering advances in manufacturing technologies led the industry’s move toward blow mold and wind style pressure vessels.
Advances in winding technologies enabled the development of larger commercial pressure vessels with both threaded and flanged openings. Commercial fabricated steel pressure vessels have utilized elaborate distribution systems to carefully control the flow of water in and out of the vessels. Their higher flow rates required carefully controlling the flow (through the vessels and the media) to ensure effective and complete water treatment.
Commercial steel vessels had an advantage, in that sophisticated distribution systems could be readily fabricated inside the vessel prior to final dome assembly. FRP, blow mold and wind seamless composite vessels all required that internal distribution components fit through the vessels end fittings. These ranged in size from 2.5 inches (residential standard) to a maximum of six inches for commercial vessels. This limited both the design and the effectiveness of the distribution systems. Washed pea gravel and garnet, filled around and above the distributors, was one method used to improve their effectiveness.
In the 1980s, Brunner Corp. introduced a residential pressure vessel composed of multiple tank liner components that allowed for the installation of a flat plate style distributor in the bottom dome of the vessel. Many today remember vividly the plant tour that Lance Fitzgerald conducted introducing this revolutionary concept. The plate was injection molded and was comprised of a polymer mesh cloth adhered to the plate assembly, which was then glued into the bottom dome assembly. This style of distributor did not require gravel under-bedding to achieve the same flow and softener capacity effectiveness.
In the 1990s, Hague Quality Water International developed and introduced a multi-part injection molded pressure vessel that advanced the plate distributor concept to the next level by including both a bottom plate and the new concept of mid-plates that would allow non-mixed multi-media beds to be contained in a single vessel. This plate assembly also utilized the molded plate with a mesh screen as the separation device.
Recently, another significant advancement of the bottom plate concept was introduced. Advances in computer aided three-dimensional design and precision CNC tooling has allowed for the bottom plate to be molded complete as a one-piece unit. Precise, uniform molded with 10-thousandths (0.010”) wide slots in a specific concentric grid pattern, it allows the designer to specifically control the flow of water through the plate more effectively than with a random gravel bed and cone style distributor. (Figure 1)The slot grid pattern is carefully molded, much like true fractal distributors, previously only available in fabricated commercial vessels.
Increased bed capacities achieved via uniform influent flow can be achieved alleviating the premature break through caused by channeling. Heavy filtration medias can now be backwashed at rates that are more consistent and in line with the flow rates of the majority of residential wells and homes, creating further system design options.
This new full plate distributor design has greater than 1.5 times the open area of a standard cone style distributor, decreasing pressure drop across the system. (Figure 2). The flow slots are specifically aligned and angled to more effectively and consistently fluidize the media bed during backwash and regeneration, utilizing a self-cleaning nozzle design. Initial testing has shown that backwash flow rates can be reduced by a minimum of 30 percent over cone and gravel style distribution systems.
With advances in composite pressure vessel manufacturing, the limitations on access to the internals of a residential or light commercial vessel are no longer defined by the openings of the vessel. Now, everything can be integrally placed inside the vessel prior to final fabrication and winding, allowing for a distributor plate design that can maximize flow and design characteristics. Bottom and mid-plate distributors can now be designed at the factory and consistently located to the customer’s specific needs, while medias can still be easily removed for re-bedding (Figure 3).
“The results are fantastic especially from the action standpoint,” said Issa Al-Kharusy of KDF Fluid Treatment, Inc. “Compared to standard basket distributors with under-bedding, in which fluidization tends to be non-uniform and concentrated around the basket, a full distributor plate vessel bed is completely fluidized at much lower flow rates and there is uniformity of fluidization when you check the entire cross section of the bed, creating a scrubbing action that starts at the plate and expands out.” (Figure 4).
Results like these allow for a lower flow rate and shorter backwash cycles, which reduces wasted water discharge in the backwash mode of filters and conditioners. Translating KDF’s findings, backwash rate can be reduced in this system design from 13 gpm/min to seven gpm/min, conserving thousands of gallons of water annually per system.
Mike Trammell of Watts Water Quality Products, Inc. described the company’s independent third-party testing of the device. “Using a full plate distributor tank, we have been able to increase the salt efficiency by nearly 80 percent over the generally accepted industry standard for conditioning systems. It’s unique features allow us to employ assembly and operational techniques that were previously unavailable to independent OEM’s. The average salt efficiency of a standard unit with gravel under-bedding is 3,333 grains per pound. We have been able to consistently achieve almost 6,000 grains per pound, reducing the amount of salt discharged to the environment – all gained through this system design.”
Water and salt savings will be realized in filter and water conditioners through required flow rate reductions (Figure 5), efficiencies gained through universal plate distribution.
With the current studies between NOWRA and WQA, water savings regulations are being watched in all states. With a new tank technology that improves on current designs and creates a ‘Wow!’ effect, a full plate distributor vessel can enable dealers to take the next step and rewrite the book of water treatment.
About the authors
Corresponding author Michael P. Mormino is Vice President of Sales & Marketing of ENPRESS LLC, located just outside of Cleveland, OH. Mormino has a bachelor’s degree in marketing and an MBA in entrepreneurship from Case Western Reserve University. He can be reached at [email protected] or by telephone at 440-510-0108 x108. Co-author Douglas M. Horner, Principal of ENPRESS LLC, is the son of the late James A. Horner, the founder of Structural Fibers.
About the company
ENPRESS® LLC is a worldwide leading manufacturer of composite pressure vessels for use in water treatment. ENPRESS® tanks are manufactured with an industry-exclusive liner design and formulation that offer superior benefits and features and is 100 percent ‘Made in the USA’. For more information about the Vortech® – the full plate distributor discussed in this article, or any other products offered by ENPRESS®, visit www.enpress.com of call 1.866.859.9274.