消防排煙風機在使用過程中可(ke)以(yi)達到(dao)很好的排(pai)煙(yan)效果,在發生火災時可(ke)以(yi)達到(dao)一定的排(pai)煙(yan)目的,可(ke)以(yi)及時將煙(yan)霧排(pai)出室內。風機的長期使用難免會出現(xian)一些噪音。以(yi)下幾種方案可(ke)以(yi)減少消防排(pai)煙(yan)風機的異常響(xiang)應。
消聲方案:消防排煙風機消聲(sheng)(sheng)是(shi)將多孔吸聲(sheng)(sheng)材(cai)料固定在(zai)氣(qi)流通道(dao)內(nei)壁,或(huo)以一定方(fang)式固定在(zai)管(guan)道(dao)上,以降低氣(qi)動噪聲(sheng)(sheng),降噪一般可以達到(dao)10-50分(fen)貝。這種處理(li)方(fang)法比較簡單,但(dan)是(shi)消音器(qi)的效果不是(shi)很明顯(xian)。
隔聲(sheng)(sheng)(sheng)(sheng)方案:隔聲(sheng)(sheng)(sheng)(sheng)法關(guan)閉噪聲(sheng)(sheng)(sheng)(sheng)源,用(yong)隔音罩(zhao)將噪聲(sheng)(sheng)(sheng)(sheng)控制在小范圍(wei)內。當聲(sheng)(sheng)(sheng)(sheng)波輻射屏蔽罩(zhao)時(shi),由于(yu)界面特性的阻抗變化,入射聲(sheng)(sheng)(sheng)(sheng)一(yi)(yi)部分(fen)(fen)被(bei)(bei)反射,一(yi)(yi)部分(fen)(fen)被(bei)(bei)吸收,一(yi)(yi)部分(fen)(fen)聲(sheng)(sheng)(sheng)(sheng)音繼續通過屏蔽罩(zhao)。材(cai)料的隔聲(sheng)(sheng)(sheng)(sheng)功能(neng)可以(yi)用(yong)傳(chuan)聲(sheng)(sheng)(sheng)(sheng)系(xi)數來表示。傳(chuan)聲(sheng)(sheng)(sheng)(sheng)系(xi)數越低,傳(chuan)遞的聲(sheng)(sheng)(sheng)(sheng)能(neng)越低,材(cai)料的隔音性能(neng)越好。
吸(xi)音(yin)方案(an):吸(xi)音(yin)材(cai)(cai)料內部有許多相互交叉(cha)的小孔。聲(sheng)(sheng)(sheng)(sheng)波(bo)撞擊(ji)這些材(cai)(cai)料的表面,通過孔進入的空氣通過這些小孔移動(dong)。由于抗(kang)碰(peng)撞和粘性(xing)(xing)(xing)運動(dong),孔壁和纖(xian)維表面附近(jin)的空氣難以(yi)運動(dong),因此聲(sheng)(sheng)(sheng)(sheng)能轉化為熱能消(xiao)耗掉。材(cai)(cai)料的吸(xi)聲(sheng)(sheng)(sheng)(sheng)性(xing)(xing)(xing)能用吸(xi)聲(sheng)(sheng)(sheng)(sheng)系數表示,吸(xi)聲(sheng)(sheng)(sheng)(sheng)系數越高,材(cai)(cai)料的吸(xi)聲(sheng)(sheng)(sheng)(sheng)性(xing)(xing)(xing)能越好。材(cai)(cai)料的吸(xi)聲(sheng)(sheng)(sheng)(sheng)性(xing)(xing)(xing)能與(yu)聲(sheng)(sheng)(sheng)(sheng)波(bo)的性(xing)(xing)(xing)質、結構和入射角以(yi)及聲(sheng)(sheng)(sheng)(sheng)波(bo)的頻率(lv)有關。