工业通风与除尘课程设计

00×1.05=16511.04m3/hР管段1Р根据L1=1.456m3/s V1=13m/s,由《工业通风》附录9查出管径和单位长度摩擦阻力。所选管径应尽量符合附录11的通风管道统一规格。РD1=360mm,Rm1=5.5Pa/mР同理,管段2РD2=360mm,Rm2=5.5Pa/mР管段4РD4=500mm,Rm4=5Pa/mР管段6РD6=630mm,Rm6=3.5Pa/mР管段7РD7=670mm,Rm7=2.5Pa/mР管段8РD8=670mm,Rm7=2.5Pa/mР确定管道3及5的管径及比摩阻Р管段3及5与管段1相同,因此РD3=D5=D1=360mm,Rm3=Rm5=Rm1=5.5Pa/mР?(5)查《工业通风》【1】附录10,确定各管段的局部阻力系数。Р①管段1Р上吸气式集气罩ζ=0.25(ɑ=90˚)Р90°弯头(R/D=1.5):1个,ζ=0.17РΣζ=0.25+0.17=0.42 Р②管段2 v2F2Р直流三通(2→4) v4F4Р根据F2+F3≈F4 α=30° ɑРF3/F4=(360/500)2=0.5184РL3/L4=1.456/2.912=0.5 查得ζ13=0.53?Р③管段3 v3F3Р上吸气式集气罩ζ=0.25(ɑ=90˚)Р60°弯头(R/D=1.25):1个,ζ=0.15Р直流三通(3→4)Рζ34=0.14РΣζ=0.25+0.15+0.14=0.54Р④管段4Р直流三通(4→6)РF4+F5 ≈F6РF5/F6=(360/630)2=0.3265РL5/L6=2.912/4.368=0.67 v4F4 v6F6Р查得ζ46=-0.3Р⑤管段5Р上吸气式集气罩ζ=0.25(ɑ=90˚) v5F5Р60°弯头(R/D=1.5):1个,ζ=0.15Р直流三通(5→6)Рζ56=0.6РΣζ=0.25+0.15+0.6=1.0