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Performances of high density polyethylene (HDPE) plastic particles heated in a microwave chamber were detailed and the effects of chamber volume (100 ml, 150 ml, and 200 ml), feeding load (10 g, 20 g, and 30 g), and microwave power (500 W, 700 W, and 900 W) were investigated. The results showed that the temperatures of HDPE plastic particles increased to 220.2 °C, 288.3 °C and 352.3 °C during the sixty minutes for the 100 ml, 150 ml and 200 ml chamber volumes, and the average heating rates were 3.36 °C/min, 4.49 °C/min and 5.5 °C/min, respectively. The temperatures of HDPE plastic particles increased to 150.8 °C, 155.4 °C and 220.2 °C for the 10 g, 20 g and 30 g feeding loads, and the average heating rates were 2.22 °C/min, 2.29 °C/min and 3.36 °C/min, respectively. The temperatures of HDPE plastic particles increased to 161.5 °C, 192.8 °C and 220.2 °C for the 500 W, 700 W and 900 W microwave powers, and the average heating rates were 2.38 °C/min, 2.89 °C/min and 3.36 °C/min, respectively. Equations were proposed to estimate the temperatures, and the relative errors were mainly between −16.46% and 16.03%.

Microwave heating performances of low density polyethylene (LDPE) plastic particles as affected by microwave power (500, 700, and 900 W), feeding load (10, 20, and 30 g), and chamber volume (100, 150, and 200 ml) were investigated and detailed in this study. The results showed that the temperatures of LDPE plastic particles increased to 159.8, 259.1 and 314.4 oC during the sixty minutes for the 500, 700 and 900 W microwave powers, and the average heating rates were 2.34, 3.96 and 4.89 oC/min, respectively. The temperatures of LDPE plastic particles increased to 140.8, 278.7 and 314.4 oC for the 10, 20 and 30 g feeding loads, and the average heating rates were 2.03, 4.28 and 4.89 oC/min, respectively. The temperatures of LDPE plastic particles increased to 314.4, 238.9 and 184.8 oC for the 100, 150 and 200 ml chamber volumes, and the average heating rates were 4.89, 3.68 and 2.76 oC/min, respectively. Equations were proposed to estimate the temperatures, and the relative errors were mainly between − 18.04% and 9.10%.

A fluidized bed system was demonstrated and the fluidization performances of silicon carbide in the fluidized bed system were experimentally studied as to facilitate the further application of microwave-assisted fluidized bed. The results show that the smaller silicon carbide particles (0.25–1 mm) have better fluidization performances than larger ones (1–1.5, 1.5–2, 2–2.5 and 2.5–3 mm) due to the fact that the smaller particles are nearly spherical whereas the larger particles are irregular in shape (long and branched), and larger particles tend to form channels in fluidization. Fluidization velocity is too high, large bubbles will be generated to affect the uniformity of fluidized particles. The loading of fluidized particles should match that of the fluidized bed, and too low loading amount wastes the space of the fluidized bed, while too high loading amount will also produce large bubbles. For the fluidized bed system developed in this study, the suggested fluidization parameters were: (a) silicon carbide particle size of 0.25–1 mm, (b) fluidization velocity of 0.47–-0.71 m/s, and (c) silicon carbide particle loading of 40–50 g.

Fluidization is an effective method to better help the transfer and conversion of fuel particles. In this study, intensification of the fluidization performances of polypropylene was experimentally investigated by using microwave absorbent. The fluidization performances of polypropylene (PP) were initially presented and the effects of microwave absorbent (SiC) particle size, mass ratio of SiC to PP, and fluidization velocity on the co-fluidization performances were studied and presented. The results showed that the PP load significantly increased the initial bed height whereas slightly increased the critical fluidization velocity and bed expansion ratio. Adding microwave absorbent (SiC) can effectively improve the fluidization performance of PP particles. The smaller SiC particles (0.25−1 mm) had better fluidization performances than the larger ones (1–1.5 mm and 1.5−2 mm). The mass ratio of silicon carbide to polypropylene decreased the critical fluidization velocity. Fluidization velocity significantly affected the co-fluidization performance. For the co-fluidization of polypropylene and silicon carbide in the designed fluidized bed, the recommended fluidization parameters were: (a) the particle size of silicon carbide of 0.25–1 mm, (b) the mass ratio of silicon carbide to polypropylene of 3:2, and (c) the fluidization velocity of 0.66 m/s.

Field investigations have demonstrated that the wear life of a carbon slider of a pantograph in a high-speed train of the 250 km/h speed class is very short. In this study, several experimental tests were performed on a high-speed test machine to understand the mechanisms of the serious wear of the slider against the wire under electric current. The experiments on the high-speed railway were carried out at electric currents of 200, 300, 400, and 500 A, sliding speeds of 100, 150, 200, and 250 km/h, and normal loads of 60, 80, 100, and 120 N. The friction coefficient, wear volume, arc electric current, arc electric voltage drop, and temperature increase of the carbon slider were recorded and analyzed. The experimental results demonstrated that the wear volume of the slider increased with the electric current and that arc melting and thermally enhanced wear were the dominant mechanisms causing the serious wear of the slider.