Straightliner Filter ™

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Straightliner Filter ™

Businesses are currently striving to lessen the impact of their energy usage on the environment and reduce their energy demands and costs. Pumping energy usage is vast for pumping fluids in the industrial processes used by Petrochemical, Food and Beverage, Chemical and Marine industries. Filtration systems are employed by these industries to separate, clean and recycle their fluids. Placement of a filter into a pumping system causes turbulence and increases the resistance: the pressure drop, across the filter which then requires the pump to increase its output and use more energy. Decreasing the pressure drop across the filter would lessen the pumping energy required and increase the filtration system’s efficiency.

Our Directors realised that the fluid flow through conventional conical filters, made with a perforated plate support and woven wire mesh (as shown on left), is non-laminar with the fluid entering, turning through an angle to pass through the filter before turning again to continue along the conduit. This may increase turbulence and decrease the efficiency of flow through the filter and thus increase the pressure drop across the filter. They came up with the idea that if the filter holes were in alignment with the direction of flow there would be a decrease in the pressure drop across the filter and so less energy would be required for pumping.

Our experienced and highly trained staff were invited to try and build, by conventional subtractive manufacturing methods, a conical Filter that had holes in the direction of flow. The benefits of this customised conical filter were not as great as expected. Inspiration was sought and delivered by the innovative potential of Additive Manufacturing (AM) and its capability to create products, layer by layer, that cannot be made by conventional manufacturing techniques. The Directors set out to design a holes-in-line conical filter that could then be produced using AM. After overcoming extensive teething hurdles in the prototype design and the AM manufacturing strategy Croft was able to produce an inline plastic conical filter (white filter on left). Croft then used Selective Laser Melting AM to manufacture the AM filter design in stainless steel 316L (as in photo). This exciting novel style AM filter has the potential of producing a smaller pressure drop as the innovative inline hole design (AM) appeared to allow a more laminar flow through the filter compared to the conventional design (CON). The AM filter and the CON filter were then tested on our testing rig (as shown) and the pressure drop across the filters recorded in response to increasing flow rates.

We were delighted to find that for the filters shown, the pressure drop for increasing flow rates for the AM filter was less than the pressure drop present with increasing flow rates for the CON filter (see Graph). The decrease in pressure drop with rising flow rates reflects a decreased in required level of pumping, thus saving energy. Croft is delighted to report this exciting new development that shows a novel design, produced by a revolutionary manufacturing technique can result in the manufacture of customised filters that can deliver savings in energy costs as well as delivering effective filtration.
This powerful new manufacturing tool expands our capabilities as problem solvers but also provides an opportunity for delivering to our customers more energy efficient filters allowing them and Croft to lower our carbon footprint.

Skills

Posted on

February 5, 2019

Skills

Posted on

February 5, 2019