The hydraulic separator Multidune: preliminary tests on fluid-dynamic features and plastic separation feasibility

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Growing environmental concerns and resource conservation needs drive plastic recycling innovation.
• The heterogeneity of plastic waste poses significant challenges to effective recycling processes.
• Traditional separation methods struggle with plastics exhibiting subtle property variations.

Purpose of the Study:

• To introduce and evaluate the Multidune separator, a novel device for plastic waste separation.
• To investigate the fluid dynamics within the Multidune separator for optimizing separation efficiency.
• To demonstrate the feasibility of separating mixed plastics using the developed apparatus.

Main Methods:

• The Multidune separator utilizes a unique configuration of semi-cylindrical tubes to create specific flow patterns.
• Particle Tracking Velocimetry (PTV) was employed to analyze the flow field and fluid dynamics.
• Eulerian analysis quantified fluid-dynamic features under varying hydraulic conditions.
• Preliminary tests on monomaterial and composite samples were conducted to determine optimal operating parameters.

Main Results:

• The Multidune separator effectively creates differential transport of low-specific-mass particles (near 1g/cm³).
• Fluid dynamics analysis revealed key features influencing particle separation within the device.
• Satisfactory separation results were achieved on composite plastic samples, validating the technology's feasibility.

Conclusions:

• The Multidune separator presents a promising advancement for the plastic recycling industry.
• The device's design facilitates the separation of mixed plastics, addressing a key recycling challenge.
• Further optimization and testing are expected to enhance the efficiency and applicability of this innovative separation technology.