靜電是指工業靜電,即(ji)在生產、儲運(yun)過程中在物料、裝置、人(ren)體、器(qi)材和構筑物上產生和積累起來的靜電。
兩種(zhong)不同(tong)性(xing)質的(de)物(wu)體相互摩(mo)擦,緊密(mi)接觸或(huo)迅(xun)速(su)剝(bo)離都會(hui)產(chan)(chan)生靜(jing)(jing)(jing)電(dian)(dian)(dian)(dian),其(qi)是一(yi)(yi)個(ge)物(wu)體失去(qu)電(dian)(dian)(dian)(dian)子(zi)帶(dai)有正電(dian)(dian)(dian)(dian)荷(he),另一(yi)(yi)個(ge)物(wu)體得(de)到電(dian)(dian)(dian)(dian)子(zi)帶(dai)負電(dian)(dian)(dian)(dian)荷(he)。如(ru)果該(gai)物(wu)體與大(da)地絕(jue)緣(yuan),則電(dian)(dian)(dian)(dian)荷(he)無法泄漏,停留在物(wu)體的(de)內(nei)部(bu)或(huo)表面而(er)呈相對靜(jing)(jing)(jing)止(zhi)狀(zhuang)態(tai),這種(zhong)電(dian)(dian)(dian)(dian)荷(he)就稱靜(jing)(jing)(jing)電(dian)(dian)(dian)(dian)。可燃化工物(wu)料(liao)、油品(pin)等(deng)在收(shou)發(fa)、輸轉、灌(guan)裝過程中,物(wu)料(liao)分子(zi)之(zhi)(zhi)間(jian)和其(qi)他物(wu)質之(zhi)(zhi)間(jian)的(de)摩(mo)擦,會(hui)產(chan)(chan)生靜(jing)(jing)(jing)電(dian)(dian)(dian)(dian),其(qi)電(dian)(dian)(dian)(dian)壓(ya)隨(sui)著(zhu)摩(mo)擦的(de)加劇而(er)增(zeng)大(da),如(ru)不及時導除,當電(dian)(dian)(dian)(dian)壓(ya)增(zeng)高到一(yi)(yi)定程度時,就會(hui)在兩帶(dai)電(dian)(dian)(dian)(dian)體之(zhi)(zhi)間(jian)閃火(huo)(huo)(即靜(jing)(jing)(jing)電(dian)(dian)(dian)(dian)放電(dian)(dian)(dian)(dian))而(er)引起油品(pin)爆炸著(zhu)火(huo)(huo)。靜(jing)(jing)(jing)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)越(yue)高越(yue)容易放電(dian)(dian)(dian)(dian)。
電(dian)壓(ya)的(de)高低或靜(jing)電(dian)電(dian)荷量大(da)小主要與下列(lie)因素有關(guan):管(guan)道內(nei)介質(zhi)流(liu)速越(yue)(yue)快,摩擦越(yue)(yue)劇(ju)烈(lie),產(chan)(chan)生(sheng)靜(jing)電(dian)電(dian)壓(ya)越(yue)(yue)高;空氣越(yue)(yue)干燥,靜(jing)電(dian)越(yue)(yue)不(bu)容易(yi)從空氣中消除,電(dian)壓(ya)越(yue)(yue)容易(yi)升高;管(guan)道內(nei)壁越(yue)(yue)粗糙,油品(pin)流(liu)經(jing)的(de)彎頭閥門越(yue)(yue)多,產(chan)(chan)生(sheng)靜(jing)電(dian)電(dian)壓(ya)越(yue)(yue)高;油品(pin)含水(shui)時,比(bi)(bi)不(bu)含水(shui)分產(chan)(chan)生(sheng)的(de)電(dian)壓(ya)高幾(ji)倍(bei)到幾(ji)十(shi)倍(bei);非金屬(shu)(shu)管(guan)道,如(ru)橡膠、塑(su)料等管(guan)道比(bi)(bi)金屬(shu)(shu)管(guan)道更容易(yi)產(chan)(chan)生(sheng)靜(jing)電(dian);管(guan)道上(shang)濾網(wang)其柵網(wang)越(yue)(yue)密,產(chan)(chan)生(sheng)靜(jing)電(dian)電(dian)壓(ya)越(yue)(yue)高。綢(chou)氈過濾網(wang)產(chan)(chan)生(sheng)的(de)靜(jing)電(dian)電(dian)壓(ya)更高;空氣的(de)溫(wen)度較高(22~40℃),空氣的(de)相(xiang)對濕(shi)度在(zai)13%~24%時,極易(yi)產(chan)(chan)生(sheng)靜(jing)電(dian);在(zai)相(xiang)同(tong)條(tiao)件下,輕(qing)質(zhi)燃料油比(bi)(bi)潤滑油易(yi)產(chan)(chan)生(sheng)靜(jing)電(dian)。
靜(jing)電(dian)(dian)(dian)的(de)危害有三種:一是可能(neng)(neng)引起(qi)爆炸和(he)火災(zai),靜(jing)電(dian)(dian)(dian)的(de)能(neng)(neng)量(liang)雖(sui)然不大,但(dan)因其(qi)電(dian)(dian)(dian)壓很高且易放電(dian)(dian)(dian)出現靜(jing)電(dian)(dian)(dian)火花;二是可能(neng)(neng)產(chan)生(sheng)(sheng)電(dian)(dian)(dian)擊(ji),靜(jing)電(dian)(dian)(dian)產(chan)生(sheng)(sheng)的(de)電(dian)(dian)(dian)擊(ji)雖(sui)然不會致(zhi)(zhi)人死亡,但(dan)是往往會導(dao)致(zhi)(zhi)二次事(shi)故,因此(ci)也(ye)要加(jia)以(yi)防(fang)范(fan);三是可能(neng)(neng)影響(xiang)生(sheng)(sheng)產(chan),在生(sheng)(sheng)產(chan)中,靜(jing)電(dian)(dian)(dian)有可能(neng)(neng)會影響(xiang)儀器(qi)設備的(de)正常運行(xing)或降低產(chan)品的(de)質(zhi)量(liang)。此(ci)外(wai),靜(jing)電(dian)(dian)(dian)還會引起(qi)電(dian)(dian)(dian)子自動(dong)元件的(de)誤操作。