Masayoshi Kimoto

New Estimation Method of Particle Size Distribution by Anisokinetic Sampling.

固気二相流中の粒径分布の測定は, 粉体プロセスの性能管理, 排煙中の粒子状物質の性状評価などにおいて, 極めて重要な操作である.従来の測定法では, 等速吸引によりサンプリングを行い, その後, 複雑な分級器を用いて粒径分布が計測されていた.本論文は, 非等速吸引による濃度測定誤差が粒子径によって異なることを粒径分布測定に利用する技術について検討したものである.非等速吸引の際の流速比 (主流流速の吸引流速に対する比率) が, 測定濃度と直線関係を持つことから容易に真濃度が求められ, また当然, 流速比は濃度比 (測定濃度の真濃度に対する比率) とも直線関係を持ち, その傾きは粒径分布によって異なる.本技術は, この概念を粒径分布測定に応用したもので, フライアッシュ, 灯油燃焼ばいじんなどについて測定した結果, 従来法と良い一致を示し, 十分な測定精度を有していることが明らかになった.

NOX reduction by multi stage air injection on pulverized coal combustion.

In order to reduce NOx and the ignition loss generated by the pulverized coal combustion, the optimum two stage combustion method and the multistage air injection method is investigated at the pulverized coal combustion test facility (standard load: 6.54 × 105 kcal/hr).The location of the air injection for the two stage combustion is suitable at the case of distance position from the burner for the NOx reduction, but suitable at the case of near the burner for the ignition loss reduction. So, the location of the air injection has the optimum point. However the optimum air injection point is used, if the air rate for two stage combustion is very high, the regeneration of NOx by the recombustion at the two stage air injection point is occured. The air rate for the two stage combustion has the upper limit.The multi-stage air injection method devide the air injection point for the two stage combustion to control the re-combustion at the case of the high air rate for the two stage combustion, and the regeneration of NOx. So, the NOx reduction rate of the multi-stage air injection method is larger than that of the two stage combustion . The air injection point and the distribution of the air injection rate for the multi-stage air injection method have the optimum values similar with the two stage combustion for both of the simultaneous reduction of NOx and ignition loss.If the injection point and the distribution of the injection air rate are optimized NOx and the ignition loss emission are lowered than that of the two stage combustion.