An Investigation on Thermal Recycling of Recycled Plastic Resin (Effects of Auxiliary Rate and Median Diameter of PET-Resin Powder on In-Furnace Combustion)

Yamakita³

2008

JEE

Self Cite

To burn PET-resin powder as an alternative or additional fuel and to realize effective thermal recycling of a great deal of wasted and recycled PET-resin, some practical studies have been made on the physical aspects of PET-powder combustion in the industrial burner. The results showed that a large amount of PET-powder up to about 80 % is exhausted without burn-up in the open atmospheric operation, whereas PET-powder is perfectly consumed in the high temperature in-furnace operation. Understanding of the relationship between the heating time and the unburnt rate of PET-powder is therefore necessary to get an important knowledge to reduce the amount of unburnt PET-powder. In this paper, the behavior of particle diameter is first modeled according to those experimentally measured, a particle-size histogram of PET-powder is then transformed into a particle-number profile by stepping the particle diameter at 0.01 µm intervals, and simple numerical prediction of the unburnt rate in the PET-powder combustion is finally attempted by introducing the parcel approximation. The results give good quantitative agreement between the unburnt rates of PET-powder measured experimentally and those predicted.

Section: Analytical Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Investigation on Thermal Recycling of Recycled Plastic Resin (Numerical Prediction of Unburnt Rate in PET-Resin Powder Combustion)

Yamakita³

2008

JEE

Self Cite

“…To certify the possibility and applicability of thermal recycling of wasted Polyethylene terephthalate resin powder, which is abbreviated to PET-powder in the following, overall infurnace combustion characteristics of the propane-fueled industrial burner have been experimentally examined in the model furnace, when PET-powder was supplied as an additional fuel (1)(2)(3) . The results proved that, when PET-powder having a mass median diameter of d m ≤ 185 µm was supplied at a replacement rate of α ≤ 30 %, (1) a spatially uniform high temperature field necessary for effective sintering process could be realized, (2) all the PET particles supplied were perfectly consumed and finally disappeared within the furnace due to perfect thermal decomposition and vaporization under high temperature circumstances, and (3) the flexible adjustability of reducing circumstances required in the final stage of sintering process was certified.…”

Section: Introductionmentioning

confidence: 99%

An Investigation on Thermal Recycling of Recycled Plastic Resin (Some Experimental Approaches for Reducing Unburnt Particle Emission in the Recycled PET-Resin Powder Combustion)

Yamakita³

et al. 2008

JEE

Self Cite

The possibility and applicability of thermal recycling of waste PET-resin have been investigated in the open atmospheric operation by supplying PET-resin powder as an auxiliary or additional fuel to the proposed twin-fuelled burner. In the preceding experiments, flow characteristics and burning processes of PET-particles in the proposed burner were investigated using PIV/PTV measurements. Appearances of flying PET-particles were optically observed and analyzed by using the doublepulsed laser, and the particle diameter was evaluated as an equivalent diameter. According to the results, some of the key factors for reducing the unburnt rate of PET-particles were clarified. In this paper, by taking these factors into consideration, an experimental attempt to reduce unburnt particle emission in the PET-resin powder combustion is carried out by varying the diameter of PET-powder supply pipe. The results specify that the increase in the dispersion degree of PET-particles reduces certainly the unburnt rate of PET-powder.

“…The preceding experimental investigations (1)(2)(3)(4)(5)(6)(7)(8)(9) have emphasized the necessity of fundamental investigations, such as high-speed and magnifying tracking of a series of processes of heating, melting, decomposing, gasifying, igniting and burning of micro plastic particles flying through a laminar premixed flame front. The latter can simulate the real situation which plastic particles experience during their passage through the combustion zone in the industrial burner.…”

Section: Introductionmentioning

confidence: 99%

Magnifying and Tracking Observation of Micro PET Particles Passing through a Plane Premixed Flame Front

Tomatsu

et al. 2007

JTST

Self Cite

In order to observe detailed behavior of micro plastic particles under rapid heating, a fundamental investigation is made by introducing two ingenious devices; one is the construction of a plane laminar premixed burner exhibiting extremely excellent two-dimensionality, the other is the construction of a magnifying particle-tracking system composed of a pair of rotating plane mirrors and a fixed high-speed video camera. Taking account of the flow patterns obtained using a PIV/PTV system, a series of heating processes from melting to burning of micro PET particles passing through a laminar flame sheet is optically observed. It is found that the proposed high-speed and magnifying tracking system can realize a wide straight range of particle tracking up to 50 mm and clarify many interesting facts concerning the ignition and burning processes of micro PET particles.