小型立式防爆起重電機

原(yuan)理：

防(fang)(fang)爆(bao)(bao)型電(dian)(dian)(dian)機(ji)的防(fang)(fang)爆(bao)(bao)原理在(zai)于：將電(dian)(dian)(dian)機(ji)的帶電(dian)(dian)(dian)部(bu)件放在(zai)特制(zhi)的外(wai)(wai)(wai)殼(ke)(ke)內，該外(wai)(wai)(wai)殼(ke)(ke)具(ju)備(bei)將殼(ke)(ke)內電(dian)(dian)(dian)氣部(bu)件產生(sheng)的火(huo)花和(he)電(dian)(dian)(dian)弧與(yu)殼(ke)(ke)外(wai)(wai)(wai)爆(bao)(bao)炸(zha)(zha)(zha)(zha)性混(hun)合(he)物(wu)隔分開的感化(hua)，并能(neng)承受進(jin)入殼(ke)(ke)內的爆(bao)(bao)炸(zha)(zha)(zha)(zha)性混(hun)合(he)物(wu)被(bei)殼(ke)(ke)內電(dian)(dian)(dian)氣設備(bei)的火(huo)花、電(dian)(dian)(dian)弧引爆(bao)(bao)時(shi)所產生(sheng)的爆(bao)(bao)炸(zha)(zha)(zha)(zha)壓力，而外(wai)(wai)(wai)殼(ke)(ke)不被(bei)損(sun)壞；同時(shi)能(neng)避免殼(ke)(ke)內爆(bao)(bao)炸(zha)(zha)(zha)(zha)生(sheng)成物(wu)向殼(ke)(ke)外(wai)(wai)(wai)爆(bao)(bao)炸(zha)(zha)(zha)(zha)性混(hun)合(he)物(wu)傳(chuan)爆(bao)(bao)，不會惹起殼(ke)(ke)外(wai)(wai)(wai)爆(bao)(bao)炸(zha)(zha)(zha)(zha)性混(hun)合(he)物(wu)熄滅和(he)爆(bao)(bao)炸(zha)(zha)(zha)(zha)。這類特別的外(wai)(wai)(wai)殼(ke)(ke)叫(jiao)“防(fang)(fang)爆(bao)(bao)外(wai)(wai)(wai)殼(ke)(ke)”。具(ju)備(bei)防(fang)(fang)爆(bao)(bao)外(wai)(wai)(wai)殼(ke)(ke)的電(dian)(dian)(dian)機(ji)稱為“防(fang)(fang)爆(bao)(bao)型電(dian)(dian)(dian)機(ji)”。防(fang)(fang)爆(bao)(bao)型電(dian)(dian)(dian)機(ji)的標記為“d”，為了完(wan)成防(fang)(fang)爆(bao)(bao)外(wai)(wai)(wai)殼(ke)(ke)耐爆(bao)(bao)和(he)防(fang)(fang)爆(bao)(bao)機(ji)能(neng)，對防(fang)(fang)爆(bao)(bao)外(wai)(wai)(wai)殼(ke)(ke)的外(wai)(wai)(wai)形、材質、容積、結構(gou)等均有特別的請求。

小型立式防爆起重電機

串聯(lian)電(dian)(dian)(dian)抗器在電(dian)(dian)(dian)機啟(qi)(qi)(qi)動時(shi)(shi)由(you)電(dian)(dian)(dian)抗器啟(qi)(qi)(qi)動，以限制和減少電(dian)(dian)(dian)機啟(qi)(qi)(qi)動時(shi)(shi)的(de)啟(qi)(qi)(qi)動電(dian)(dian)(dian)流和電(dian)(dian)(dian)壓(ya)(ya)降(jiang)。當電(dian)(dian)(dian)機穩(wen)定，電(dian)(dian)(dian)流達到一定值時(shi)(shi)，切除的(de)反應器成為電(dian)(dian)(dian)機的(de)直(zhi)接啟(qi)(qi)(qi)動方式。由(you)于啟(qi)(qi)(qi)動過(guo)程(cheng)中電(dian)(dian)(dian)機側電(dian)(dian)(dian)壓(ya)(ya)也降(jiang)低，容易導致啟(qi)(qi)(qi)動轉矩(ju)不足，啟(qi)(qi)(qi)動過(guo)程(cheng)中會(hui)有兩個沖(chong)擊過(guo)程(cheng)。

自耦變(bian)壓(ya)器的(de)(de)(de)啟動是指電(dian)動機(ji)(ji)啟動時采用自耦變(bian)壓(ya)器來降低(di)電(dian)機(ji)(ji)定(ding)(ding)子(zi)(zi)繞組(zu)(zu)(zu)的(de)(de)(de)啟動電(dian)壓(ya)。電(dian)機(ji)(ji)啟動后，電(dian)機(ji)(ji)與自耦變(bian)壓(ya)器分離，在滿(man)壓(ya)下(xia)正常運(yun)行。優點是可(ke)(ke)以(yi)根(gen)據(ju)允(yun)許的(de)(de)(de)啟動電(dian)流和所需(xu)的(de)(de)(de)啟動轉矩來選擇不(bu)同的(de)(de)(de)自耦變(bian)壓(ya)器分接，無論電(dian)機(ji)(ji)定(ding)(ding)子(zi)(zi)繞組(zu)(zu)(zu)的(de)(de)(de)定(ding)(ding)子(zi)(zi)繞組(zu)(zu)(zu)或電(dian)機(ji)(ji)定(ding)(ding)子(zi)(zi)繞組(zu)(zu)(zu)的(de)(de)(de)三角(jiao)形連接都可(ke)(ke)以(yi)使用。缺點是設備的(de)(de)(de)尺寸(cun)很(hen)大，而且成(cheng)本更貴。

可(ke)變電(dian)阻(zu)軟啟(qi)動(dong)(dong)包括熱電(dian)阻(zu)起動(dong)(dong)和液體電(dian)阻(zu)起動(dong)(dong)。主要是(shi)通(tong)過改變回路中的(de)(de)液體阻(zu)力來(lai)分(fen)擔局部壓降。隨著(zhu)啟(qi)動(dong)(dong)時(shi)間的(de)(de)延長，可(ke)變電(dian)阻(zu)上的(de)(de)壓降減小，防爆電(dian)機順利啟(qi)動(dong)(dong)。可(ke)變電(dian)阻(zu)啟(qi)動(dong)(dong)的(de)(de)啟(qi)動(dong)(dong)方式在啟(qi)動(dong)(dong)時(shi)較好，但(dan)不(bu)適合頻(pin)繁啟(qi)動(dong)(dong)。