車間排風(fēng)系統(tǒng)設(shè)計(jì)說(shuō)明書(shū)

年5月29日車間排風(fēng)系統(tǒng)設(shè)計(jì)說(shuō)明書(shū)文檔僅供參考某車間局部排風(fēng)系統(tǒng)設(shè)計(jì)說(shuō)明書(shū)車間大小:長(zhǎng)*寬*高=30m*10m*6m1#,2#,3#3個(gè)浸漆槽(散發(fā)有機(jī)溶劑)槽面尺寸:0.5m*1m,0.5m*0.5m,1.0m*2.0m槽面高:0.9m溫度:20°C壓力:1標(biāo)準(zhǔn)大氣壓在槽上方設(shè)計(jì)外部吸氣罩,罩口至槽面距離H=0.5m.計(jì)算排風(fēng)罩尺寸及排風(fēng)量選型所需要運(yùn)用公式:(1).罩口尺寸:罩長(zhǎng)邊A=槽長(zhǎng)邊+0.4*h*2罩短邊B=槽短邊+0.4*h*2(2).罩口周長(zhǎng):P=罩長(zhǎng)邊*2+罩短邊*2(3).排風(fēng)量:L=KPH(4).當(dāng)量直徑:D=2*a*b/(a+b)(5).實(shí)際流速:v=排風(fēng)量/矩形風(fēng)管尺寸(6).△P=R*(7).動(dòng)壓=ρ**/2(8).Z=動(dòng)壓*∑ξ(9).Rl+Z=△P+Z根據(jù)書(shū)表3-3取邊緣控制點(diǎn)的控制風(fēng)速=0.4m/s分別計(jì)算各槽的排風(fēng)罩尺寸及排風(fēng)量1#:罩口尺寸:長(zhǎng)邊A=1+0.4*0.5*2=1.4m短邊B=0.5+0.4*0.5*2=0.9m罩口周長(zhǎng):P=1.4*2+0.9*2=4.6m排風(fēng)量:L=KPH=1.4*4.6*0.5*0.4=1.288m/s=4600m/h2#:罩口尺寸:長(zhǎng)邊A=0.5+0.4*0.5*2=0.9m短邊B=0.5+0.4*0.5*2=0.9m罩口周長(zhǎng):P=0.9*2+0.9*2=3.6m排風(fēng)量:L=KPH=1.4*3.6*0.5*0.4=1.008m/s=3600m/h3#:罩口尺寸:長(zhǎng)邊A=2.0+0.4*0.5*2=2.4m短邊B=1.0+0.4*0.5*2=1.4m罩口周長(zhǎng):P=2.4*2+1.4*2=7.6m排風(fēng)量:L=KPH=1.4*7.6*0.5*0.4=2.128m/s=7700m/h根據(jù)排風(fēng)量設(shè)計(jì)通風(fēng)管道對(duì)各管段進(jìn)行編號(hào),標(biāo)出管段長(zhǎng)度和各排風(fēng)點(diǎn)的排風(fēng)量(m/s)2．選定最不利環(huán)路,本系統(tǒng)選擇1-3-5-風(fēng)機(jī)-6為最不利環(huán)路。3．根據(jù)各管段的風(fēng)量及選定的流速,確定最不利環(huán)路上各管段的斷面尺寸和單位長(zhǎng)度摩擦阻力。根據(jù)書(shū)表6-2,風(fēng)管內(nèi)最小風(fēng)速為,干管10m/s,支管5m/s管段1根據(jù)L=4600m/h(1.288m/s),v=10m/s由附錄6查出管徑和單位長(zhǎng)度摩擦阻力。所選管徑應(yīng)盡量符合附錄8的通風(fēng)管道統(tǒng)一規(guī)格。D=350mmR=3.1Pa/mS=192325取矩形風(fēng)管尺寸400*320當(dāng)量直徑D=350實(shí)際流速v=10.06同理可查得其它管段的管徑及單位長(zhǎng)度摩擦阻力并確定矩形風(fēng)管尺寸,當(dāng)量直徑,及實(shí)際流速(見(jiàn)表1-1)。查附錄7,確定各管段的局部阻力系數(shù)管段1設(shè)備密閉罩ξ=1.0對(duì)應(yīng)接管動(dòng)壓90彎頭(R/D=1.5)1個(gè)ξ=0.17直流三通(1-3)根據(jù)F+F>FF/F=(444/444)=1L/L=3600/8300=0.434查得ξ=0.16∑ξ=1.0+0.17+0.16=1.33管段2設(shè)備密閉罩ξ=1.0對(duì)應(yīng)接管動(dòng)壓90彎頭(R/D=1.5)1個(gè)ξ=0.1760彎頭(R/D=1.5)1個(gè)ξ=0.15合流三通(2-3)ξ=0.32∑ξ=1.0+0.17+0.15+0.32=1.64管段3F+F>Fа=30F/F=(615/615)=1L/L=7700/16000=0.481ξ=0.33(4)管段4設(shè)備密閉罩ξ=1.0對(duì)應(yīng)接管動(dòng)壓90彎頭(R/D=1.5)1個(gè)ξ=0.1760彎頭(R/D=1.5)1個(gè)ξ=0.15合流三通ξ=0.25∑ξ=1.0+0.17+0.15+0.25=1.57(5)管段5風(fēng)機(jī)進(jìn)口漸擴(kuò)管近似選出一臺(tái)風(fēng)機(jī),風(fēng)機(jī)進(jìn)口直徑D=700mmL=400mmF/F=(700/615)=1.14Tanа=1/2((700-615)/400)=0.11а=6.06ξ=0.02(6)管段6風(fēng)機(jī)出口漸擴(kuò)管風(fēng)機(jī)出口尺寸600*600D=615F/F=(800*500)/(600*600)=1.11ξ=0帶擴(kuò)散管的傘形風(fēng)帽(h/D=0.5)ξ=0.60∑ξ=0.60管段編號(hào)no流量L(m/s)管長(zhǎng)L(m)處選風(fēng)速V(m/s)當(dāng)量直徑D(mm)矩形風(fēng)管尺寸M(mm)實(shí)際流速v(m/s)11.2881010350400*32010.0621.00845444500*4005.0432.30610444500*40011.4842.1345615800*5005.3254.42410615800*50011.0664.42410615800*50011.06單位長(zhǎng)度摩擦阻力R(pa/m)摩擦阻力△P(pa)動(dòng)壓P(pa)局部阻力系數(shù)∑ξ局部阻力Z(pa)管段阻力R+Z(pa)3.13160.721.3380.76111.80.522.615.241.6425.027.61.910.479.070.3326.136.50.321.616.981.5726.728.31.35.273.390.021.476.671.35.273.390.6044.0349.23表1-15．對(duì)并聯(lián)管路進(jìn)行阻力平衡匯合點(diǎn)A△P=111.8△P=27.6(△P-△P)/△P=(111.8-27.6)/111.8=76%>10%為了是管段1,2達(dá)到阻力平衡,改變管段2的管徑,增大其阻力D=D(△P/△P)=444(27.6/111.8)=324.12mm根據(jù)通風(fēng)管道統(tǒng)一規(guī)格。取D=330mmP=27.6(444/330)=29.5pa(△P-△P)/△P=(111.8-236.5)/111.8=67.4%此時(shí)仍處于不平衡狀態(tài),如繼續(xù)減小管徑,取D=320mm其對(duì)應(yīng)的阻力為28.1pa,同樣處于不平衡狀態(tài),因此決定取D=330mm,在運(yùn)行時(shí)再輔以閥門調(diào)節(jié),消除不平衡匯合點(diǎn)BP+△P=111.8+36.5=148.3paP=28.3pa((△P+△P)-△P)/(△P+△P)=80.9%不符合要求,需要加閥門調(diào)節(jié)6．計(jì)算系統(tǒng)的總阻力△P=∑(Rl+Z)=111.8+27.6+36.5+28.3+6.7=210.9pa7.選擇風(fēng)機(jī)風(fēng)機(jī)風(fēng)量L=1.15L=1.15*16000=18400m/h風(fēng)機(jī)風(fēng)壓P=1.15△P=1.15*