機械密封沖刷的(de)目(mu)的(de)是為了防止(zhi)雜質堆積，防止(zhi)氣囊(nang)形(xing)成，保持和(he)改善潤滑等(deng)，當沖刷液溫度較低時(shi)，兼有(you)冷卻作用。下面(mian)向大家解說機械密封的(de)沖刷技巧。　　

1、內沖刷　　

正沖刷：利用工作主機的被密封(feng)介質，由泵的出口(kou)端通過管(guan)路引入密封(feng)腔(qiang)。主要用于清潔流體(ti)。當(dang)溫度高或(huo)有雜(za)質時，可在(zai)機械密封(feng)管(guan)路上設置(zhi)冷卻器、過濾器等。　　

反(fan)沖(chong)刷(shua)(shua)(shua)：利用(yong)(yong)工作(zuo)主機(ji)的(de)被密(mi)(mi)封(feng)(feng)介(jie)質，由泵的(de)出口端(duan)引(yin)入密(mi)(mi)封(feng)(feng)腔，沖(chong)刷(shua)(shua)(shua)后通(tong)(tong)過(guo)管(guan)(guan)(guan)路流(liu)回(hui)(hui)泵進口。主要(yao)用(yong)(yong)于(yu)清潔流(liu)體。全沖(chong)刷(shua)(shua)(shua)是利用(yong)(yong)工作(zuo)主機(ji)的(de)被密(mi)(mi)封(feng)(feng)介(jie)質，由泵的(de)出口端(duan)通(tong)(tong)過(guo)管(guan)(guan)(guan)路引(yin)入密(mi)(mi)封(feng)(feng)腔，沖(chong)刷(shua)(shua)(shua)后再經管(guan)(guan)(guan)路流(liu)回(hui)(hui)泵進口。該方法在冷卻效果上較好。　　

2、外沖(chong)(chong)(chong)(chong)刷：引入外系統(tong)與被密封(feng)介質(zhi)相容的(de)(de)清(qing)(qing)潔流體(ti)至密封(feng)腔(qiang)進行沖(chong)(chong)(chong)(chong)刷。外沖(chong)(chong)(chong)(chong)刷液(ye)壓(ya)(ya)力應比被密封(feng)介質(zhi)大0.05-0.1MPA，合用于(yu)(yu)介質(zhi)為(wei)高溫或(huo)固(gu)體(ti)顆(ke)粒的(de)(de)場合。沖(chong)(chong)(chong)(chong)刷液(ye)的(de)(de)流量應保證(zheng)帶(dai)走熱(re)量，還需知足沖(chong)(chong)(chong)(chong)刷的(de)(de)需要(yao)，不(bu)會(hui)產生對密封(feng)件的(de)(de)沖(chong)(chong)(chong)(chong)蝕。為(wei)此，需控制(zhi)密封(feng)腔(qiang)的(de)(de)壓(ya)(ya)力和沖(chong)(chong)(chong)(chong)刷的(de)(de)流速，一(yi)般清(qing)(qing)潔沖(chong)(chong)(chong)(chong)刷液(ye)的(de)(de)流速應小于(yu)(yu)5M/S；含(han)有顆(ke)粒的(de)(de)漿狀液(ye)體(ti)須(xu)小于(yu)(yu)3M/S，為(wei)達到上述的(de)(de)流速值，沖(chong)(chong)(chong)(chong)刷液(ye)與密封(feng)腔(qiang)壓(ya)(ya)力的(de)(de)差(cha)值應≤0.5MPA，一(yi)般取0.05-0.1MPA，對雙端面機(ji)械密封(feng)可取0.1--0.2MP。沖(chong)(chong)(chong)(chong)刷液(ye)進入和排出密封(feng)腔(qiang)的(de)(de)孔口位置，應設(she)置在(zai)機(ji)械密封(feng)端面四周，且應在(zai)靠近動環側，為(wei)了防(fang)止石(shi)墨環被沖(chong)(chong)(chong)(chong)蝕或(huo)因冷卻不(bu)均引起溫差(cha)變形，以(yi)及(ji)雜質(zhi)堆積和結焦(jiao)等，可采用切向引入或(huo)多點(dian)沖(chong)(chong)(chong)(chong)刷。必要(yao)時，沖(chong)(chong)(chong)(chong)刷液(ye)可以(yi)是熱(re)水(shui)或(huo)蒸汽(qi)。