公开(公告)号：US5568777A

公开(公告)日：1996-10-29

申请号：US359800

申请日：1994-12-20

申请人： Bernard P. Breen ,  John P. Bionda, Jr. ,  James E. Gabrielson ,  Anthony Hallo

发明人： Bernard P. Breen ,  John P. Bionda, Jr. ,  James E. Gabrielson ,  Anthony Hallo

IPC分类号： F23D1/00 ,  F23C1/10

CPC分类号： F23D1/00 ,  F23D2201/10 ,  F23D2201/20

摘要： An improved pulverized coal burner that reduces the formation of nitrogen oxides. The coal burner includes fuel splitters that separate a mixture of primary air and coal into a plurality of streams while the mixture is discharged through a diffuser having a plurality of partially open areas and a plurality of blocked areas. After passing through the diffuser, the plurality of streams are discharged into a furnace to be burned. The plurality of partially open areas and blocked areas are created by removing sections of the diffuser and replacing the removed sections with fuel splitters. Creation of these discrete streams delays mixing with secondary air. Because primary air is supplied in sub-stoichiometric quantities, the coal in these split streams will be burned under fuel-rich conditions for the first 100 to 200 milliseconds of combustion, until the delayed mixing of secondary air occurs. Combustion in a fuel-rich environment retards formation of nitrogen oxides in two ways. First, nitrogen that is part of the volatile matter that is evolved during the early stages of combustion will tend to form molecular nitrogen rather than react with oxygen to form nitrogen oxides. Second, an oxygen deficiency will reduce formation of nitrogen oxides from atmospheric nitrogen.

摘要翻译： 一种改进的粉煤燃烧器，可减少氮氧化物的形成。 煤燃烧器包括燃料分配器，其将一次空气和煤的混合物分离成多个流，同时通过具有多个部分开放区域和多个阻塞区域的扩散器排出混合物。 在通过扩散器之后，将多个流排出到待燃烧的炉中。 通过去除扩散器的部分并且用燃料分离器代替去除的部分来产生多个部分开放区域和阻塞区域。 这些离散流的创建延迟了与二次空气的混合。 由于一次空气以亚化学计量的方式供应，这些分流中的煤将在富燃料条件下燃烧第一个100至200毫秒的燃烧，直到发生二次空气的延迟混合。 在富含燃料的环境中的燃烧有两种方式阻碍了氮氧化物的形成。 首先，作为在燃烧的早期阶段演化的挥发性物质的一部分的氮将倾向于形成分子氮而不是与氧反应形成氮氧化物。 第二，缺氧会减少氮氧化物从大气氮的形成。

公开(公告)号：US5546874A

公开(公告)日：1996-08-20

申请号：US362290

申请日：1994-12-22

申请人： Bernard P. Breen ,  John P. Bionda, Jr. ,  James E. Gabrielson ,  Roger W. Glickert ,  Anthony Hallo

发明人： Bernard P. Breen ,  John P. Bionda, Jr. ,  James E. Gabrielson ,  Roger W. Glickert ,  Anthony Hallo

IPC分类号： F23C5/00 ,  F23C1/10

CPC分类号： F23C5/00 ,  F23C2201/102 ,  F23C2900/05081

摘要： A method and apparatus for reducing the formation of nitrogen oxides during combustion in a roof-fired furnace is disclosed. By blocking at least some of the fuel nozzles associated with a roof-fired burner while leaving open the secondary air openings associated with the blocked fuel nozzles, reduction in NOX emissions from roof-fired furnaces is accomplished. This blocking results in the creation of a localized fuel-rich or just slightly fuel-lean environment near open fuel nozzles because part of the secondary air needed for combustion is being added at a location distant from where the initial combustion occurs. By creating a localized fuel-rich or slightly fuel-lean environment near the open fuel nozzles, the initial stages of combustion occur with little or no excess oxygen present. Because much of the fuel-bound nitrogen is liberated during the initial stages of combustion, it will preferentially react to form molecular nitrogen rather than nitrogen oxides because of the lack of available oxygen. Further, by the time all the secondary air is mixed with the pulverized coal to complete substantially the combustion, the flame temperature will have been sufficiently lowered by heat transfer to the boiler tubes that thermal formation of nitrogen oxides will be reduced. This invention works well in those roof-fired furnaces where individual burners are composed of multiple fuel nozzles and the fuel nozzles eject primary air and fuel between boiler tubes which form the furnace roof.

摘要翻译： 公开了一种用于在屋顶燃烧炉中燃烧期间减少氮氧化物形成的方法和装置。 通过阻挡与屋顶燃烧的燃烧器相关联的至少一些燃料喷嘴，同时打开与堵塞的燃料喷嘴相关联的二次空气开口，从而实现了屋顶燃烧炉的NO x排放的减少。 这种阻塞导致在打开的燃料喷嘴附近产生局部富燃料或仅略微贫燃环境，因为燃烧所需的二次空气的一部分被添加在远离初始燃烧发生的位置。 通过在敞开的燃料喷嘴附近产生局部的富含燃料或稍微贫燃的环境，燃烧的初始阶段几乎没有或没有过量的氧存在。 由于大部分燃料结合的氮在燃烧的初始阶段被释放，由于缺乏可用的氧，它将优先反应形成分子氮而不是氮氧化物。 此外，当所有的二次空气与粉煤混合以完全燃烧时，通过传递到锅炉管的火焰温度将被充分降低，氮氧化物的热形成将被减少。 本发明在那些屋顶燃烧炉中工作良好，其中单个燃烧器由多个燃料喷嘴组成，并且燃料喷嘴在形成炉顶的锅炉管之间喷射一次空气和燃料。

公开(公告)号：US5694869A

公开(公告)日：1997-12-09

申请号：US365853

申请日：1994-12-29

申请人： Bernard P. Breen ,  John P. Bionda, Jr. ,  James E. Gabrielson ,  Anthony Hallo ,  John M. Koltick, Jr.

发明人： Bernard P. Breen ,  John P. Bionda, Jr. ,  James E. Gabrielson ,  Anthony Hallo ,  John M. Koltick, Jr.

IPC分类号： F23C6/04 ,  F23J11/00

CPC分类号： F23C6/045 ,  F23C2201/10

摘要： An improved method and apparatus for supplying combustion air in a roof-fired furnace. Part of the combustion air, overfire air, enters through the roof of a roof-fired furnace at positions separate from the coal burners. The separated entry of overfire air ensures that the initial stages of combustion occur in a fuel-rich environment. A fuel-rich environment during the early stages of combustion favors the formation of molecular nitrogen and disfavors the formation of nitrogen oxides during combustion. The overfire air flows roughly parallel to the flow of combustion products emanating from the coal burners. The overfire air can be angled by vanes either slightly towards or slightly away from the combustion products, depending on how long combustion needs to be retarded in order to inhibit the formation of nitrogen oxides.

摘要翻译： 一种用于在屋顶燃烧炉中供应燃烧空气的改进方法和装置。 燃烧空气的一部分，超燃空气通过屋顶燃烧炉的屋顶进入与煤燃烧器分开的位置。 超燃空气的分离进入确保了燃料的初始阶段在富燃料环境中发生。 在燃烧早期阶段，富含燃料的环境有利于分子氮的形成，并且在燃烧过程中不利于氮氧化物的形成。 过火空气大致平行于从燃煤机发出的燃烧产物的流动。 过热空气可以通过稍微朝向或稍微远离燃烧产物的叶片成角度，这取决于为了抑制氮氧化物的形成而需要延迟燃烧。