大型物於氣泡式流體化床焚化爐中之燃燒特性

The Characterization of Combustion for Large Objects in a Bubbling Bed Incinerator

古正彬(Jeng-Bin GU)

指導教授 ： 錢建嵩

中原大學/工學院/化學工程學系/碩士(2007年)

https://doi.org/10.6840/cycu200700730

摘要

一般焚化爐都以連續進料燃燒，鮮少使用間斷性進料燃燒。而在處理特殊的有害廢棄物，如軍事及醫療廢棄物，係因具危害性，而不可進行切割、破碎等處理，則必須採取批次或半批次進料於焚化爐內燃燒，以防有害物質外漏釀成災害。
本研究於一總高4.6 m，乾舷區內徑0.75 m，氣泡床區為0.8 m × 0.4 m之矩形氣泡式流體化床焚化爐(Bubbling Fluidized Bed Incineration, BFBI)中以大型木塊(ø 10.5 cm × 28 cm)進行研究，採取半批次(semi-batch)進料，模擬大型物燃燒之特性。操作變數包括：一次風量、床溫、進料頻率及靜床高，探討於半批次進料大型物下，操作變數對爐出口溫度、NOx及CO排放之影響。
研究結果顯示，由於木塊之揮發物含量高，爐內最高溫出現於飛濺區。出口NOx濃度並未受半批次進料影響，呈現高頻低振幅波動；出口CO濃度則隨著進料頻率呈現週期性變化。出口NOx及CO平均濃度皆隨一次風量增加而下降；改變床溫對出口NOx及CO平均濃度化影響不明顯。出口NOx之平均濃度隨靜床高產生先升後降的趨勢，於靜床高35 cm時，有一最大值。出口CO平均濃度隨著其排放濃度之平均振幅變大而增加。當每批次進料量越大時，出口平均溫度振幅越大，使得出口NOx濃度波動較明顯。本實驗之最佳操作參為:一次風量 = 3.7 Nm3/min、床溫 = 800℃、進料頻率= 1 batch/10min及靜床高 = 42 cm。

關鍵字

半批次進料 ； 氣泡式流體化床焚化爐 ； 大型物的燃燒

並列摘要

In this study, all the experiments were carried out in a pilot scale bubbling fluidized bed incineration of 0.75 m I.D. and 4.6 m in height. The semi-batch feeding was used in this investigation. The Woodblock (ø 10.5 cm × 28 cm) was used as feeding material, and silica sand was employed as the bed material.
The effects of various operating conditions on CO and NOx emissions at the outlet combustor temperature were investigated. The operating parameters studied included primary air, bed temperature, feeding cycle and static bed height.
The experimental results show that the highest temperature of the incinerator takes place in splashing zone. It can be attributed to the combustion of high volatile matter content of woodblock. In this study, the NOx emissions affected hardly by semi-batch feeding, and reveal the high frequency and low oscillation amplitude. The CO emissions present the periodic change, and decreases with the outlet combustor temperature. The mean CO emission is affected hardly by bed temperature. The CO and NOx emissions decrease with increasing the primary air. The mean CO emission increases with its emission oscillation amplitude. Original data of CO and NOx emissions reveal opposite tendency. The optimum operating condition for this of experiments is primary air of 3.7 Nm3/min, bed temperature of 800℃, feeding cycle of 10 min for a charge, and static bed height of 28 cm.

並列關鍵字

Bubbling fluidized bed incinerator ； combustion of large objects ； semi-batch feeding

參考文獻

楊宗翰，【廢液於渦旋式流體化床焚化爐中氧化亞氮排放之研究】，私立中原大學化學工程學系碩士論文，(2003)。

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