- 學位論文
流體化床焚化爐中以間歇式進料探討燃料大小之燃燒行為
The Effect of Fuel Size on the Combustion Behavior in a Fluidized Bed Incinerator with Intermittent Feeding System
摘要
中文摘要 一般大型焚化爐都以連續進料燃燒，鮮少使用間歇式進料燃燒。而在處理特殊的有害廢棄物，如感染性事業廢棄物(即為醫療廢棄物)，係因具危害性，而不可進行切割、破碎等處理，則必須採取間歇式進料於焚化爐內燃燒，以防有害物質外漏釀成災害，因此本研究選用此方法進行實驗。 本研究於一總高4.6 m，燃燒室為0.8 m × 0.4 m，乾舷區內徑0.75 m之渦旋式流體化床焚化爐(Vortexing Fluidized Bed Incineration, VFBI)中以不同粒徑之橡膠球( 29、59、94mm)進行研究，採取間歇式進料，模擬不同大小廢棄物於間歇式進料流體化床焚化爐中對其燃燒行為之影響。並藉由改變操作參數如：橡膠粒徑、投料時間間隔、床下計量氧比與過量氧比，探討操作參數對於爐內溫度分佈與氣態污染物NOX跟CO的關係，以瞭解爐內之燃燒情形。 結果顯示，爐內溫度會隨進料時間點改變而呈現週期變化，最高溫度會因為橡膠粒徑之關係出現於飛濺區或乾舷區。在爐出口CO濃度會隨著投入橡膠粒徑增大而減小，主要是由於粒徑較小之橡膠去揮發時間較短，因此投入時產生大量揮發物至乾舷區；投料時間間隔增加時CO濃度也會有增加之趨勢。爐出口NOX濃度在投料時間間隔較小時會隨著粒徑增加而有所增加。
並列摘要
Abstract It always uses continuous feeding in incinerator. In infectious wastes(or medical waste) combustion which is usually enwrapped in package to prevent hazardous material emitting to the environment. Intermittent batch feeding is applied for this kind feeding material. In this study, all the experiments were carried out in a pilot scale vortexing fluidized bed incineration of 4.6 m in height and 0.75 m I.D.. The intermittent feeding was used in this investigation. The different size rubber (ø 29、59、94 mm) were used as feeding material to simulate the waste, also silica sand was employed as the bed material. The effects of various operating conditions on mean bed temperature, mean freeboard temperature, mean CO and NOx emissions were investigated. The operating parameters including rubber diameter, interval time of feeding, under bed stoichiometric oxygen ratio, excess oxygen ratio were studied. The experimental results show that the highest temperature of the incinerator takes place in splash zone or freeboard zone by used the different size rubber. The CO emission will increase with rubber diameter or interval time of feeding increasing due to the smaller rubber burning time is short and release a large amount of volatile. The NOx emission increase rubber diameter increasing in the smaller interval time of feeding.