Exploiting metal additive manufacturing to deliver Innovation in wedge wire filter media designs

N. Burns*, M. Burns, Croft Filters Limited; D. Travis, L. Geekie, Croft Additive Manufacturing Limited, UK

Industrial filters are employed to remove particulates from fluids to prevent contamination or damage to downstream industrial processes. Wedge wire filter media are considered to be highly dependable filtration media that deliver precision filtering. Wedge wire filters have strength and can withstand high operational pressures. They are also not susceptible to clogging and so are easy to maintain. As a result they are widely employed across a range of industries including water management, hydroelectric, food & beverage and manufacturing.

Wedge wire screens can be flat panels, curved screens, segments as well as cylinders: slotted tube filters. Traditionally, wedge wire filter media are manufactured using conventional processes where the wedge profiles are resistance welded to supports to form the overall shape.

Wedge profiles are cut to length before welding to support profiles for wedge screens where as for some wedge wire cylinders a single wedge wire is wound round the supports, maintaining a constant distance to deliver the correct filtration level (Figure 2). Both of these methods require tooling and lead time can be 4-6 weeks.

Figure 2; Conventional wedge wire cylinder filter, where wedge wire is a single wire (left). Metal AM wedge wire cylinder, produced as a single part

AM technology has the capability to produce complex shapes, some of which cannot be manufactured conventionally, prototypes, tooling and multi-parts as single parts. We have previously utilised AM technology to deliver innovative filtration media designs. Wedge wire cylinder filters are produced as a single unit without tooling (Figure 2) and this AM design can be adapted to suit different size slots, wedge profile and end fitting type. The design freedom of layer by layer manufacturing provides the opportunity for the wedge wire to be shaped in a form not usually produced in current manufacturing processes.

Here we will develop AM wedge wire designs for a self-cleaning wedge wire filter for water catchment in river flow. The first challenge is to design a self cleaning shape that also can withstand water pressure and turbulence and river debris. The second challenge is produce the wedge wire filter to have the required slot size for effective filtration....

Session: F6 - Filter Media - Advanced Manufacturing Methods
Day: 15 March 2018
Time: 09:00 - 10:15 h

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