鍋爐風機噪聲的危害及其防治對策初探
來(lai)源(yuan)：廣州紫科生物環保技(ji)術有限公(gong)司 閱讀：2854 更新時間：2008-06-06 16:41目前在很多(duo)企(qi)業，受工(gong)業生產和供(gong)暖需求，鍋(guo)爐的(de)安裝、使用非常普及(ji)。但(dan)很多(duo)鍋(guo)爐由于存在選址欠佳(jia)和風機性能不良等因(yin)(yin)素，鍋(guo)爐噪(zao)聲(sheng)影響周圍居民安靜(jing)的(de)工(gong)作、生活環(huan)境(jing)，損害人民身(shen)體健康，常常引發擾民事件，產生糾紛。經統(tong)計，2004年我(wo)區(qu)因(yin)(yin)噪(zao)聲(sheng)引發的(de)信訪案(an)件占(zhan)環(huan)境(jing)信訪案(an)件的(de)30%。因(yin)(yin)此，鍋(guo)爐風機噪(zao)聲(sheng)治理日益重要。
1、 環境噪聲污染的(de)危害
噪(zao)(zao)聲(sheng)(sheng)對人(ren)(ren)體(ti)(ti)的(de)影(ying)響(xiang)和(he)危害一般可(ke)分為勞(lao)動保護(hu)和(he)環境(jing)保護(hu)兩方面，前面指危害人(ren)(ren)的(de)身體(ti)(ti)健康(kang)，導致各種疾病的(de)發(fa)(fa)生(sheng)，后者指干(gan)(gan)擾(rao)環境(jing)安靜，影(ying)響(xiang)人(ren)(ren)們正常的(de)工作和(he)生(sheng)活。噪(zao)(zao)聲(sheng)(sheng)對人(ren)(ren)體(ti)(ti)健康(kang)危害主要表(biao)現在：損傷聽力，造成噪(zao)(zao)聲(sheng)(sheng)性耳(er)聾；導致大腦皮層興奮和(he)平衡(heng)失(shi)調，腦血(xue)管功(gong)能損害，導致神經衰弱；損傷心血(xue)管系統，引發(fa)(fa)消(xiao)化系統失(shi)調，影(ying)響(xiang)內分泌；干(gan)(gan)擾(rao)人(ren)(ren)們正常的(de)生(sheng)活、休息、語言(yan)交談(tan)和(he)日常的(de)工作學習，分散(san)注意力，降低工作效(xiao)率。
2、 噪聲(sheng)治理的(de)基本原理
形成(cheng)(cheng)噪(zao)(zao)聲污染(ran)主要是三個因素，即：聲源、傳播(bo)媒介和接(jie)收體。只有這三者(zhe)(zhe)同時存在(zai)，才(cai)能對聽(ting)者(zhe)(zhe)形成(cheng)(cheng)干擾。從這三方(fang)面入手，通(tong)過降(jiang)低聲源、限制(zhi)噪(zao)(zao)聲傳播(bo)、阻斷(duan)噪(zao)(zao)聲的接(jie)收等手段(duan)，來(lai)達(da)到控(kong)制(zhi)噪(zao)(zao)聲的目的，在(zai)具體的噪(zao)(zao)聲控(kong)制(zhi)技(ji)術(shu)上，可采(cai)用吸聲、隔聲和消聲三種措施。
2.1吸聲
當(dang)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)入射(she)到(dao)物體(ti)表(biao)(biao)面(mian)時(shi)，部(bu)分聲(sheng)(sheng)(sheng)(sheng)(sheng)能(neng)(neng)(neng)要(yao)被物體(ti)吸(xi)(xi)收(shou)轉(zhuan)化(hua)為其(qi)他(ta)形式的(de)(de)(de)(de)能(neng)(neng)(neng)量(liang)，稱為吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)。材(cai)(cai)料(liao)的(de)(de)(de)(de)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)性能(neng)(neng)(neng)用吸(xi)(xi)收(shou)系(xi)數(shu)(shu)來表(biao)(biao)示(shi)，吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)系(xi)數(shu)(shu)越大，則(ze)表(biao)(biao)示(shi)材(cai)(cai)料(liao)的(de)(de)(de)(de)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)性能(neng)(neng)(neng)越好。材(cai)(cai)料(liao)的(de)(de)(de)(de)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)性能(neng)(neng)(neng)與材(cai)(cai)料(liao)的(de)(de)(de)(de)性質、結構和(he)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)的(de)(de)(de)(de)入射(she)角度(du)及聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)的(de)(de)(de)(de)頻率有關(guan)。多(duo)(duo)孔(kong)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)材(cai)(cai)料(liao)的(de)(de)(de)(de)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)機(ji)理是(shi)：材(cai)(cai)料(liao)內(nei)(nei)部(bu)有無(wu)數(shu)(shu)細小的(de)(de)(de)(de)相互貫(guan)通的(de)(de)(de)(de)孔(kong)洞(dong)，當(dang)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)入射(she)到(dao)這些材(cai)(cai)料(liao)的(de)(de)(de)(de)表(biao)(biao)面(mian)，進(jin)而入射(she)到(dao)這些細小的(de)(de)(de)(de)孔(kong)隙內(nei)(nei)時(shi)，要(yao)引(yin)起(qi)孔(kong)隙內(nei)(nei)的(de)(de)(de)(de)空氣運動，緊靠孔(kong)壁(bi)和(he)纖維表(biao)(biao)面(mian)的(de)(de)(de)(de)空氣，因摩擦(ca)和(he)粘滯運動阻力而不易運動，使聲(sheng)(sheng)(sheng)(sheng)(sheng)能(neng)(neng)(neng)轉(zhuan)化(hua)為熱能(neng)(neng)(neng)而消耗掉。故性能(neng)(neng)(neng)良(liang)好的(de)(de)(de)(de)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)材(cai)(cai)料(liao)要(yao)多(duo)(duo)孔(kong)，孔(kong)與孔(kong)之間互相貫(guan)通，并且貫(guan)通的(de)(de)(de)(de)孔(kong)洞(dong)要(yao)與外界連通，使聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)能(neng)(neng)(neng)進(jin)入材(cai)(cai)料(liao)內(nei)(nei)部(bu)。如(ru)對應1000赫茲(zi)聲(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)(bo)，10cm厚(hou)的(de)(de)(de)(de)超細玻(bo)璃(li)棉(mian)的(de)(de)(de)(de)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)系(xi)數(shu)(shu)是(shi)0.87。
2.2隔聲
隔(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)所采用(yong)(yong)的方法是(shi)將噪聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)源封(feng)閉起來(lai)，使噪聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)控制在一個小的空(kong)間內，這種隔(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)結構稱為隔(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)罩。在聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)遇到屏蔽(bi)物時，由于界面特性(xing)阻抗(kang)的改變，入(ru)射(she)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)能(neng)(neng)的一部(bu)分(fen)被(bei)反射(she)，一部(bu)分(fen)被(bei)吸(xi)收，一部(bu)分(fen)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)能(neng)(neng)透進屏蔽(bi)物繼續傳(chuan)播。材(cai)料的隔(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)性(xing)能(neng)(neng)可用(yong)(yong)透聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)系數來(lai)表(biao)示。透聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)系數越小，表(biao)示透進去(qu)的聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)能(neng)(neng)越少，材(cai)料的隔(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)性(xing)能(neng)(neng)越好。材(cai)料的隔(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)性(xing)能(neng)(neng)與隔(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)體的結構、性(xing)質和(he)入(ru)射(she)聲(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)波(bo)的頻(pin)率有關。
2.3消聲
消(xiao)聲(sheng)是將多(duo)孔吸(xi)聲(sheng)材料(liao)固定(ding)在氣(qi)流通道內(nei)壁，或按一定(ding)方式固定(ding)在管道中，以達到削弱空氣(qi)動力性(xing)噪(zao)聲(sheng)的(de)目的(de)，消(xiao)聲(sheng)量一般可達到10—50分貝。
3、 風機噪(zao)聲治理技術
鍋爐(lu)(lu)房的(de)鼓(gu)風(feng)(feng)(feng)機(ji)(ji)和引風(feng)(feng)(feng)機(ji)(ji)噪聲(sheng)(sheng)一般在(zai)(zai)(zai)90分貝左(zuo)(zuo)右，因(yin)輸送(song)的(de)鍋爐(lu)(lu)煙氣(qi)(qi)(qi)溫度高(gao)達(da)180℃，采用(yong)封閉隔(ge)(ge)(ge)聲(sheng)(sheng)會導致散熱(re)不(bu)良，電(dian)機(ji)(ji)溫度過高(gao)，甚至燒(shao)毀(hui)電(dian)機(ji)(ji)。因(yin)此，在(zai)(zai)(zai)工(gong)藝上將(jiang)風(feng)(feng)(feng)機(ji)(ji)降(jiang)(jiang)(jiang)噪和節能兩(liang)方面結(jie)合起來。經(jing)實踐，鍋爐(lu)(lu)風(feng)(feng)(feng)機(ji)(ji)節能降(jiang)(jiang)(jiang)噪綜合治理方案為：對(dui)鍋爐(lu)(lu)房的(de)工(gong)藝布(bu)置保持不(bu)變，將(jiang)鼓(gu)風(feng)(feng)(feng)機(ji)(ji)、引風(feng)(feng)(feng)機(ji)(ji)分別置在(zai)(zai)(zai)隔(ge)(ge)(ge)聲(sheng)(sheng)室(shi)(shi)(shi)(shi)內(nei)，用(yong)通風(feng)(feng)(feng)管將(jiang)它(ta)們與主機(ji)(ji)相(xiang)連接(jie)，在(zai)(zai)(zai)隔(ge)(ge)(ge)聲(sheng)(sheng)室(shi)(shi)(shi)(shi)頂上或墻面上開(kai)設進(jin)氣(qi)(qi)(qi)口(kou)，并安裝(zhuang)消聲(sheng)(sheng)器(qi)供機(ji)(ji)房進(jin)風(feng)(feng)(feng)使用(yong)。平面布(bu)置時(shi)將(jiang)鼓(gu)風(feng)(feng)(feng)機(ji)(ji)靠(kao)近(jin)鍋爐(lu)(lu)房一側，進(jin)風(feng)(feng)(feng)口(kou)在(zai)(zai)(zai)上風(feng)(feng)(feng)側，電(dian)機(ji)(ji)置于(yu)氣(qi)(qi)(qi)流(liu)通道(dao)中(zhong)間。鍋爐(lu)(lu)運行時(shi)，由(you)于(yu)鼓(gu)風(feng)(feng)(feng)機(ji)(ji)在(zai)(zai)(zai)隔(ge)(ge)(ge)聲(sheng)(sheng)室(shi)(shi)(shi)(shi)內(nei)產生負壓，大(da)量的(de)室(shi)(shi)(shi)(shi)外新鮮空(kong)(kong)氣(qi)(qi)(qi)就會自動進(jin)入隔(ge)(ge)(ge)聲(sheng)(sheng)室(shi)(shi)(shi)(shi)，首(shou)先和引風(feng)(feng)(feng)機(ji)(ji)電(dian)機(ji)(ji)進(jin)行熱(re)交換，使之冷卻降(jiang)(jiang)(jiang)溫，室(shi)(shi)(shi)(shi)內(nei)溫度保持50℃左(zuo)(zuo)右。該方案中(zhong)由(you)于(yu)隔(ge)(ge)(ge)聲(sheng)(sheng)室(shi)(shi)(shi)(shi)和進(jin)風(feng)(feng)(feng)消聲(sheng)(sheng)器(qi)的(de)降(jiang)(jiang)(jiang)噪能力都比較大(da)，降(jiang)(jiang)(jiang)噪的(de)效果容易實現。鼓(gu)風(feng)(feng)(feng)機(ji)(ji)將(jiang)預熱(re)的(de)空(kong)(kong)氣(qi)(qi)(qi)送(song)入鍋爐(lu)(lu)燃(ran)燒(shao)，回收利用(yong)能源(yuan)，具有一定的(de)經(jing)濟效益(yi)。
為保證治理(li)(li)(li)效果和(he)鍋(guo)爐設(she)(she)備正(zheng)常運行(xing)，在設(she)(she)計施工中，應根據具(ju)體要(yao)求(qiu)，考慮噪聲(sheng)(sheng)(sheng)的(de)(de)(de)聲(sheng)(sheng)(sheng)強、聲(sheng)(sheng)(sheng)頻等因素，對(dui)隔(ge)聲(sheng)(sheng)(sheng)、吸(xi)(xi)聲(sheng)(sheng)(sheng)和(he)通風散熱進(jin)行(xing)詳(xiang)細設(she)(she)計，做(zuo)好細部處理(li)(li)(li)。對(dui)隔(ge)聲(sheng)(sheng)(sheng)室(shi)的(de)(de)(de)大小厚度，吸(xi)(xi)聲(sheng)(sheng)(sheng)材料的(de)(de)(de)種類、厚度進(jin)行(xing)計算。進(jin)風消聲(sheng)(sheng)(sheng)器的(de)(de)(de)消聲(sheng)(sheng)(sheng)量一般選用(yong)25db（a）左(zuo)右。盡量減少噪聲(sheng)(sheng)(sheng)輻射面積，去掉不必要(yao)的(de)(de)(de)金屬板面。控制(zhi)板面的(de)(de)(de)振動，在聲(sheng)(sheng)(sheng)源與隔(ge)聲(sheng)(sheng)(sheng)罩及基礎(chu)之(zhi)間(jian)用(yong)軟(ruan)性材料連(lian)接(jie)。鼓風機的(de)(de)(de)連(lian)接(jie)管(guan)道(dao)和(he)薄壁鋼板煙囪是噪聲(sheng)(sheng)(sheng)治理(li)(li)(li)的(de)(de)(de)薄弱環節，在管(guan)壁外包扎5cm厚的(de)(de)(de)玻璃纖(xian)維棉(mian)，用(yong)鋼絲扎緊后，再用(yong)2cm厚的(de)(de)(de)鋼絲網水泥粉(fen)刷。將玻璃纖(xian)維棉(mian)固定(ding)在鋼板上，吸(xi)(xi)收隔(ge)聲(sheng)(sheng)(sheng)室(shi)內的(de)(de)(de)混響(xiang)噪聲(sheng)(sheng)(sheng)。
4、 降(jiang)噪和節能效果(guo)
4.1降噪效果
如(ru)果風(feng)機噪聲(sheng)(sheng)是90分(fen)貝(bei)，采(cai)用3mm鋼板的(de)隔聲(sheng)(sheng)罩，其理論隔聲(sheng)(sheng)量是32分(fen)貝(bei)。隔聲(sheng)(sheng)罩內襯(chen)10cm厚的(de)玻璃棉(mian)，其吸聲(sheng)(sheng)系數(shu)是0.87，在進(jin)氣管安裝消聲(sheng)(sheng)器，則實(shi)際隔聲(sheng)(sheng)量為
tl=32+10 log20.87=30分貝(bei)
故風機(ji)噪聲治理后達到：t=90-30=60分貝(bei)
聲(sheng)壓級和聲(sheng)強是反映聲(sheng)音(yin)的(de)客(ke)觀物理量(liang)，人(ren)體(ti)對噪聲(sheng)的(de)主觀感受用響度表示：n=2(n-40)/10(宋)
治理前(qian)的風機響度為：n1=2(90-40)/10=32(宋)
治理前的風機響度為：n2=2(60-40)/10=4(宋)
故治理前后響度(du)降低87.5%
4.2節能效果
機(ji)房內設(she)備的散熱(re)主要(yao)有三個方面：
①引風(feng)機與(yu)管道壁(bi)面的對流散(san)熱，
②引風機與管道壁面(mian)的輻射散熱，
③風機(ji)(ji)電機(ji)(ji)的散熱。根(gen)據通風工程原理，節能(neng)降噪系(xi)統(tong)還(huan)可以回收部分熱量。
經過實踐，采用鍋爐風(feng)機噪聲(sheng)節能(neng)降噪治理技術，既降低了(le)噪聲(sheng)污染(ran)，保障了(le)人民群眾的生活環境(jing)，又(you)回收利用了(le)能(neng)源(yuan)，達(da)到了(le)經濟、環境(jing)效益的統一(yi)。
