It seems mundane, but filtration, the mechanical or physical process used to separate solids from fluids or gases, is a critical technology which permeates modern manufacturing methods.
It's fairly simple; place a medium through which only fluids can pass in the path of a gas or liquid's flow to remove fine, unwanted or dangerous particle solids. It's crucially important in chemistry for the separation of materials of different chemical composition, and it's widely used as one of the unit operations in chemical engineering.
In filtration, a multilayer lattice holds back particles too large to follow the complex channels of a simpler filter.
Now a team of researchers at Lancaster University led by Neil Burns, Bhavani Vijayakumar, Allan Rennie and Louise Geekie have arrived at a chemical free technology for removing particles during fluid flow using additive manufacturing techniques to fine-tune the filters themselves.
Burns, a founder and co-director at Croft Filters and Croft Additive Manufacturing, has more than 25 years of experience developing and delivering high quality filtration solutions to a range of industries and he's part of the Science and Technology Facilities Council CERN Business Incubation Centre aimed at bridging the gap between science and industry.
The team says they've pushed the efficiency of filters and strainers forward through the use of direct fabrication and additive manufacturing (AM) technologies.
By replacing the conventional manufacturing technique of punching, rolling and seam-welding, they say improvements in filter support geometries have resulted for specific applications by optimizing fluid flow. It's this flexibility in design via AM technology and selective laser melting which has improved flow and lowered pressure drop in design simulations,
The researchers say that by creating geometrically optimized, conical, in-line filter supports for existing filtration and pumping systems, efficiency gains and a reduction of raw materials used in the manufacturing process may reduce the energy consumption by 57% and create material savings of up to 53%.
Subtractive manufacturing has been the standard method of producing complex filtration products, but Burns says AM technology will improve operational efficiencies and reduce the need for tooling by manufacturing the item in a single step directly from CAD data.
As a result of the research, Croft Filters manufactured stainless steel 316 filters which were designed to remove contaminants found in pipelines. The same technology was used to create wedge wire filters and Burns says they're integral to a number of high performance filtration applications in the oil and gas industries. Such filters require V-shaped bars to be welded to end-caps and a machined-threaded end.
Working with Burns, Croft simplified the process using a Realizer SLM-250 metal 3D printing machine. By doing away with the labor-intensive method of joining separate components together, Burns says designers now have the option to change the size of the filtration area and the aperture size, with a wide variety of fittings and ends available.