More Productive Painting
Electrostatic separation cuts costs, energy use, environmental impact.
Continuous improvements in efficiency and quality, reduced energy consumption, minimized emissions—these are the metrics by which the success of automotive and other high-volume paint shops are measured.
Paint system supplier Eisenmann Corporation (Crystal Lake, IL) says its newly developed electrostatic separation system for paint overspray can help painters achieve their productivity and conservation goals by reducing waste, cutting operating costs and minimizing environmental impact.
The E-Scrub system directs air in the spray booth so that surplus paint mist (overspray) produced during painting is routed via funnel-shaped run-off surfaces known as flood sheets into a new electrostatic separation system. Part of the overspray is immediately bound using a separating agent on the flood sheets, while the bulk of the paint material continues through the electrostatic separation portion of the system.
The separation process begins in “separating modules” at the bottom of the flood sheets. The high-voltage modules are fitted with positively charged separating plates which are also rinsed with separating agent in a circulating system. High-voltage wires also run horizontally between the separating plates inside the module. Paint particles in the circulating air stream become negatively charged as they pass near the high-voltage wires and are attracted by the positively charged separating plates. They are then bound by the separating agent and discharged into a bottom-mounted collecting pan. According to Eisenmann, the chemical composition of the separating agent causes bound paint particles to combine in the collecting pan and form solid agglomerates, which can then be removed and disposed of without difficulty.
The company says electrostatic charging of paint overspray particles and binding of overspray in the separating agent maximizes collection efficiency, enabling the system to meet stringent air quality requirements. The German clean air regulation “Technical Instructions on Air Quality Control” (commonly known as TA Luft), for example, permits maximum dust emissions of 3 mg/m3. According to Eisenmann, the E-Scrub system can cut emissions to well below the regulation, to 0.3 mg/m3.
The system operates with 95% recirculated air. Eisenmann says this results in energy savings of up to 78% compared with conventional wet scrubber technology, as well as an 87% reduction in water usage and considerably reduced chemicals usage. The electrostatic system switches on and off in accordance with production, yielding further energy savings.
Electrostatic paint overspray separation improves paint quality by eliminating complex mechanical filtration systems and ensuring constant flow rates without pressure fluctuations, Eisenmann says. The system is also said to be considerably quieter and easier to service than mechanical systems, with fewer components than conventional wet scrubber systems. It can be retrofitted quickly and simply in existing paint plants.
Related Content
-
EPA Readying Fall Nationwide PFAS Survey of Metal Finishing Industry to Inform New Water Discharge Rule
NASF continues discussions with US EPA on the agency’s plans for a nationwide survey of the metal finishing industry on its use of PFAS. NASF plans to review the draft survey and provide feedback to the agency prior to its distribution. Surveys will likely go to a wide range of job shop and captive operations and are scheduled to be sent out in the fall.
-
NASF/AESF Foundation Research Project #121: Development of a Sustainability Metrics System and a Technical Solution Method for Sustainable Metal Finishing - 15th Quarterly Report
This NASF-AESF Foundation research project report covers the twelfth quarter of project work (October-December 2023) at Wayne State University in Detroit. In this period, our main effort focused on the development of a set of Digital Twins (DTs) using the Physics-Informed Neural Network (PINN) technology with application on parts rinsing simulation.
-
NASF/AESF Foundation Research Project #122: Electrochemical Approaches to Treatment of PFAS in Plating Wastewater - 5th Quarterly Report
This paper covers a research grant at the University of Georgia - Griffin on developing electrochemical approaches to remove PFASs present in plating wastewaters, under the direction of Professor Qingguo (Jack) Huang. This fifth quarter report assessed eight PFAAs most commonly found in wastewaters, by electro-oxidation with a Ti4O7 anode across a range of anodic potentials in solutions of different compositions and at varying operating conditions.