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Show - 3 - a) the ori9inal furnace deaign (aee figure 2) b) a partially .adified deaign c) a cOlilpletely new furnace deaign. aa.ed on a thorough a.seasillent of the varioua conditione inve.ti9a ted, a final furnace de.ign configuration v.. ..l.cted which provided the highe.t degree of turbulence and aixing, both of which are neces aary for good combuatioo. (See figure 3.) Aa part of the incinerator mdlficatione, the following illlpOrtant de.iCJD con.iderationa wer. addreea~dl a) an illlprcwed pri.ary air distribution .y.te_ vaa install.d, b) the ' nozzle 48.iCJll and location of the secondary air .yet •• vere .elected, c) the configuration and poai tioning of the front and rear furnace -bull noee.- wer. 4eterain.d to optimize mixing, d) combu.tion gas reaidence ti .. vas incr .... d 30\ by enlarging the upper furnace chaaber. combaatlon air is. provided to the furnace at two locations, under the grates (pri-.ry 'air) and above the grate. (.eccmdary air). '!'b. priary air is drawn from the refuse pit area and i. .o4ulated continuoualy by .uti-blade dampera OIl the pri.ary air fan. Pri.ary air on the ~fied unit is distributed to 9 zan.a located beneath the grat .. , each fitted vith i.ndiridual .:>torized and flow-controlled 4a~ra. Pri-.ry air aupplied to the downatr __ end of the drying grate provide. the neceaaary combustion air requir.d for early ignition of the refuse. Air to the burning grate i. di.tributed into 6 hopp.r zonea of approximately the ..- aize. Bach of the hopper zones can auto_tic:ally control air flova and pr ... ures, through .eparate dueta fro. the pri.ary air header. Thi. f.ature prevent. exce •• i... a.J\lDta of cOillbuation air from bypaa.ing the large refuse pile. on the grate and reducea carryover of fin. _terial fro •• ections of the grate wher. the pile. are •• ll.r. The fini.hing grate air 1. .upplied through two hopper zones vith indiYidual damper. and en.ure. that all the refuae 18 burned prior to discharging into the aah pit. SecQlldary air is introduced into the furnace radiation chalilber by one •• ries of Dozzles at the front -bull noae- aDd another aeri.. at the rear -bull noee-. Air for the.e Dozzl •• i. al.o drawn from the refuse storage pit area by a fan. '!'he nozzles have ind! vidual -.nual dampers for control. purpo.es and to ensure that all provide equal flowa. To achi.ve the required air distribution between the front and r.ar Dozzl •• , a control damper is elliployed to adjust the di.tribution. Good control of air flova through theae nozzles is ililportant .ince they are used to reduce flue gas te~ratures and maintain the de.ired exceaa air level, while achieving sufficient mixing for completing co~uation. |