靜電(dian)是指(zhi)工業靜電(dian),即(ji)在生產、儲運過程中在物料、裝置、人體(ti)、器(qi)材和(he)構(gou)筑(zhu)物上產生和(he)積累起(qi)來的靜電(dian)。
兩種不(bu)同性質的物(wu)(wu)(wu)體(ti)相(xiang)互摩(mo)擦,緊密(mi)接觸(chu)或(huo)迅速剝離都(dou)會產(chan)生(sheng)靜(jing)(jing)(jing)電(dian),其是一個物(wu)(wu)(wu)體(ti)失去電(dian)子帶(dai)有(you)正電(dian)荷(he)(he),另一個物(wu)(wu)(wu)體(ti)得到電(dian)子帶(dai)負電(dian)荷(he)(he)。如(ru)(ru)果該物(wu)(wu)(wu)體(ti)與大地絕緣,則電(dian)荷(he)(he)無法泄漏,停留在(zai)(zai)物(wu)(wu)(wu)體(ti)的內(nei)部或(huo)表(biao)面而呈相(xiang)對靜(jing)(jing)(jing)止狀態,這種電(dian)荷(he)(he)就(jiu)稱靜(jing)(jing)(jing)電(dian)。可燃(ran)化(hua)工物(wu)(wu)(wu)料、油品等(deng)在(zai)(zai)收發、輸轉(zhuan)、灌裝過(guo)程中(zhong),物(wu)(wu)(wu)料分子之(zhi)(zhi)間(jian)和其他(ta)物(wu)(wu)(wu)質之(zhi)(zhi)間(jian)的摩(mo)擦,會產(chan)生(sheng)靜(jing)(jing)(jing)電(dian),其電(dian)壓隨著(zhu)(zhu)摩(mo)擦的加(jia)劇而增大,如(ru)(ru)不(bu)及時導除,當(dang)電(dian)壓增高(gao)到一定程度時,就(jiu)會在(zai)(zai)兩帶(dai)電(dian)體(ti)之(zhi)(zhi)間(jian)閃(shan)火(即靜(jing)(jing)(jing)電(dian)放(fang)電(dian))而引起油品爆炸著(zhu)(zhu)火。靜(jing)(jing)(jing)電(dian)電(dian)壓越(yue)高(gao)越(yue)容易放(fang)電(dian)。
電(dian)壓(ya)(ya)的(de)高(gao)(gao)(gao)低或(huo)靜(jing)電(dian)電(dian)荷量(liang)大(da)小主要(yao)與下(xia)列(lie)因素有關:管道(dao)內介(jie)質流(liu)速(su)越快,摩擦越劇烈,產(chan)生靜(jing)電(dian)電(dian)壓(ya)(ya)越高(gao)(gao)(gao);空(kong)氣(qi)越干燥(zao),靜(jing)電(dian)越不容易從空(kong)氣(qi)中消除,電(dian)壓(ya)(ya)越容易升高(gao)(gao)(gao);管道(dao)內壁越粗糙,油(you)(you)品(pin)流(liu)經(jing)的(de)彎頭閥門越多(duo),產(chan)生靜(jing)電(dian)電(dian)壓(ya)(ya)越高(gao)(gao)(gao);油(you)(you)品(pin)含水(shui)時,比不含水(shui)分(fen)產(chan)生的(de)電(dian)壓(ya)(ya)高(gao)(gao)(gao)幾(ji)(ji)倍(bei)到(dao)幾(ji)(ji)十(shi)倍(bei);非金屬(shu)管道(dao),如橡膠、塑料等管道(dao)比金屬(shu)管道(dao)更(geng)(geng)容易產(chan)生靜(jing)電(dian);管道(dao)上(shang)濾(lv)網其(qi)柵網越密,產(chan)生靜(jing)電(dian)電(dian)壓(ya)(ya)越高(gao)(gao)(gao)。綢氈過濾(lv)網產(chan)生的(de)靜(jing)電(dian)電(dian)壓(ya)(ya)更(geng)(geng)高(gao)(gao)(gao);空(kong)氣(qi)的(de)溫(wen)度較高(gao)(gao)(gao)(22~40℃),空(kong)氣(qi)的(de)相(xiang)對濕度在(zai)13%~24%時,極易產(chan)生靜(jing)電(dian);在(zai)相(xiang)同(tong)條件(jian)下(xia),輕質燃料油(you)(you)比潤滑油(you)(you)易產(chan)生靜(jing)電(dian)。
靜(jing)(jing)電(dian)(dian)的(de)危害有(you)三種:一是(shi)可(ke)(ke)能(neng)(neng)引起(qi)爆炸(zha)和(he)火災,靜(jing)(jing)電(dian)(dian)的(de)能(neng)(neng)量雖然(ran)不大,但(dan)因其電(dian)(dian)壓很高且易放電(dian)(dian)出現(xian)靜(jing)(jing)電(dian)(dian)火花;二是(shi)可(ke)(ke)能(neng)(neng)產(chan)(chan)生電(dian)(dian)擊,靜(jing)(jing)電(dian)(dian)產(chan)(chan)生的(de)電(dian)(dian)擊雖然(ran)不會(hui)致人死亡,但(dan)是(shi)往往會(hui)導(dao)致二次事故,因此也要加(jia)以(yi)防范;三是(shi)可(ke)(ke)能(neng)(neng)影響生產(chan)(chan),在生產(chan)(chan)中,靜(jing)(jing)電(dian)(dian)有(you)可(ke)(ke)能(neng)(neng)會(hui)影響儀器設備(bei)的(de)正常運行或降低(di)產(chan)(chan)品的(de)質量。此外(wai),靜(jing)(jing)電(dian)(dian)還會(hui)引起(qi)電(dian)(dian)子自動元件的(de)誤操作。