Effect of cone angles of a hydrocyclone for the separation of waste plastics with low value of density difference.

The cone angle of a hydrocyclone is believed to be an important parameter to affect the separation performance. For the recycling of waste plastics, this paper focused on the study of the influence of cone angles on the separation of light dispersed plastics (PET) and heavy dispersed plastics (PVC) by experiments and numerical simulations. The cone angle was changed from 3° to 28° either at given length of the cylindrical section or at fixed total length of the hydrocyclone.

Study on the light medium separation of waste plastics with hydrocyclones.

The separation of waste plastics is an important part of solid waste recycling. Based on the density difference between high density polyethylene (HDPE) and polypropylene (PP), this paper used the experimental research and CFD numerical simulation to study the separation performance by using the light medium separation technology with hydrocyclones. Results showed that with the increase of feed flow rate, the pressure drop increased as a power function, the Newton efficiency peaked at the feed flow rate of 3.

Effect of the medium's density on the hydrocyclonic separation of waste plastics with different densities.

Hydrocyclones can be applied to recycle waste plastics with different densities through separating plastics based on their differences in densities. In the process, the medium density is one of key parameters and the value of the medium's density is not just the average of the density of two kinds of plastics separated. Based on the force analysis and establishing the equation of motion of particles in the hydrocyclone, a formula to calculate the optimum separation medium density has been deduced.