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發布(bu)時間:2022-01-10 11:33:20 人(ren)氣(qi):125751 來(lai)源:
在對碭山機械密封泄漏原因進行分析時,要根據實踐經驗、現場觀察并借助儀器測量,弄清楚密封元件與密封性能之間的內在聯系,全方位檢查密封環、傳動件、加載彈性元件、輔助密封圈、防轉機構、緊固螺釘、底座、軸套、密封腔體以及密封系統等部位,綜合分析,找出碭山機械密封泄漏原因,以此為依據,選擇正確的碭山機械密封。
1.機械磨損
碭山機械密封泄漏中較為常見的就是機械磨損,機械磨損導致密封副端面產生分離,造成密封泄漏。機械磨損還會破壞密封副的正常配合關系,使傳動軸轉動時引起密封元件發生軸向位移和擺動,導致碭山機械密封泄漏。這種碭山機械密封泄漏可根據碭山機械密封副磨損痕跡的具體情況進行準確判斷。如果密封磨損痕跡均勻而產生泄漏,說明碭山機械密封泄漏的出現是由其他部位引起的。此時需要檢測其他部位而非密封本身。如果密封副沒有磨損痕跡而出現泄漏,說明可能是動環相對于靜環不旋轉或者出現打滑,可以對防轉銷或底座進行檢測,確定是否是防轉銷脫落了或者底座的孔徑與密封件的外徑不相匹配所致。如果碭山機械密封副磨損痕跡很深,則有(you)可(ke)能是傳(chuan)動(dong)軸轉動(dong)時(shi)密(mi)封(feng)副出現分離,有(you)大顆粒(li)物質嵌入軟質碳端面(mian),此時(shi)可(ke)用硬(ying)質材(cai)料(liao)作為(wei)密(mi)封(feng)副材(cai)料(liao)。
2.由熱損傷引起的密封泄(xie)漏
機械產生過大的熱量往往造成碭山機械密封副變形、熱裂或(huo)皰疤,引起(qi)泄漏。
熱(re)(re)裂主(zhu)要(yao)是機(ji)(ji)械(xie)(xie)密封(feng)(feng)(feng)在(zai)干摩擦(ca)或冷卻系統發生中斷(duan)等(deng)情(qing)況下,造成機(ji)(ji)械(xie)(xie)密封(feng)(feng)(feng)在(zai)短(duan)時(shi)間(jian)內承受超(chao)負(fu)荷熱(re)(re)量(liang)而出(chu)現(xian)密封(feng)(feng)(feng)環表面(mian)徑向裂紋。由(you)于熱(re)(re)裂往(wang)往(wang)引(yin)起密封(feng)(feng)(feng)環磨損加(jia)劇,造成大(da)(da)量(liang)的泄漏,所以(yi)在(zai)設計(ji)機(ji)(ji)械(xie)(xie)密封(feng)(feng)(feng)時(shi)要(yao)充分考慮機(ji)(ji)械(xie)(xie)材(cai)料(liao)(liao)的物(wu)理(li)性(xing)質,并(bing)要(yao)根據機(ji)(ji)械(xie)(xie)材(cai)質設定特定的運轉條件。皰疤主(zhu)要(yao)是由(you)于碳石墨導(dao)致粘結劑(ji)被擠出(chu),出(chu)現(xian)密封(feng)(feng)(feng)泄漏。由(you)于介質的潤滑性(xing)、操作溫度、線(xian)速(su)度、配(pei)對材(cai)料(liao)(liao)組合等(deng)因素的影(ying)響都(dou)會(hui)使(shi)機(ji)(ji)械(xie)(xie)密封(feng)(feng)(feng)產生大(da)(da)量(liang)熱(re)(re)能,所以(yi)為了使(shi)機(ji)(ji)械(xie)(xie)密封(feng)(feng)(feng)摩擦(ca)熱(re)(re)能及(ji)時(shi)散(san)(san)發,改變端面(mian)面(mian)積(ji)比、減少載荷、靜止型密封(feng)(feng)(feng)并(bing)加(jia)導(dao)流(liu)套都(dou)能較好(hao)地改善密封(feng)(feng)(feng)的散(san)(san)熱(re)(re)條件,保證機(ji)(ji)械(xie)(xie)密封(feng)(feng)(feng)的正常運行。
3.由腐蝕(shi)引起的密(mi)封泄漏(lou)
機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)的(de)(de)(de)(de)腐(fu)(fu)蝕(shi)(shi)(shi)(shi)是(shi)(shi)(shi)引起(qi)(qi)機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)泄漏最主(zhu)要(yao)原因(yin)之一,一般有化學腐(fu)(fu)蝕(shi)(shi)(shi)(shi)和電(dian)(dian)(dian)化學腐(fu)(fu)蝕(shi)(shi)(shi)(shi)。化學腐(fu)(fu)蝕(shi)(shi)(shi)(shi)主(zhu)要(yao)是(shi)(shi)(shi)由于機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)長時間(jian)與腐(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)介(jie)(jie)質(zhi)接觸引起(qi)(qi)的(de)(de)(de)(de)。這(zhe)種(zhong)(zhong)腐(fu)(fu)蝕(shi)(shi)(shi)(shi)對機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)影響較大(da),甚至會(hui)導(dao)致機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)金屬(shu)晶界的(de)(de)(de)(de)破(po)壞或(huo)斷裂。電(dian)(dian)(dian)化學腐(fu)(fu)蝕(shi)(shi)(shi)(shi)主(zhu)要(yao)是(shi)(shi)(shi)密(mi)(mi)(mi)封(feng)(feng)(feng)環兩種(zhong)(zhong)金屬(shu)在(zai)電(dian)(dian)(dian)介(jie)(jie)質(zhi)溶液(ye)中產(chan)生(sheng)電(dian)(dian)(dian)位差,導(dao)致機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)產(chan)生(sheng)電(dian)(dian)(dian)池腐(fu)(fu)蝕(shi)(shi)(shi)(shi)。不管是(shi)(shi)(shi)化學腐(fu)(fu)蝕(shi)(shi)(shi)(shi)還是(shi)(shi)(shi)電(dian)(dian)(dian)化學腐(fu)(fu)蝕(shi)(shi)(shi)(shi)對機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)都有很大(da)的(de)(de)(de)(de)影響,所以(yi)在(zai)機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)材料選取上要(yao)考慮密(mi)(mi)(mi)封(feng)(feng)(feng)元(yuan)(yuan)件(jian)(jian)的(de)(de)(de)(de)精密(mi)(mi)(mi)性(xing),選擇比(bi)主(zhu)機(ji)(ji)更耐腐(fu)(fu)蝕(shi)(shi)(shi)(shi)的(de)(de)(de)(de)材料。機(ji)(ji)械(xie)(xie)密(mi)(mi)(mi)封(feng)(feng)(feng)腐(fu)(fu)蝕(shi)(shi)(shi)(shi)速度(du)(du)(du)的(de)(de)(de)(de)快慢(man)與壓(ya)力、溫度(du)(du)(du)和滑(hua)動速度(du)(du)(du)都有密(mi)(mi)(mi)切的(de)(de)(de)(de)關系(xi)。當(dang)密(mi)(mi)(mi)封(feng)(feng)(feng)元(yuan)(yuan)件(jian)(jian)所承(cheng)受的(de)(de)(de)(de)壓(ya)力增大(da)、溫度(du)(du)(du)升高、滑(hua)動速度(du)(du)(du)加快時,密(mi)(mi)(mi)封(feng)(feng)(feng)元(yuan)(yuan)件(jian)(jian)的(de)(de)(de)(de)腐(fu)(fu)蝕(shi)(shi)(shi)(shi)速度(du)(du)(du)也會(hui)加快。針對這(zhe)些(xie)因(yin)素,采取雙端面密(mi)(mi)(mi)封(feng)(feng)(feng)可(ke)以(yi)減少密(mi)(mi)(mi)封(feng)(feng)(feng)元(yuan)(yuan)件(jian)(jian)的(de)(de)(de)(de)零(ling)件(jian)(jian)與腐(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)介(jie)(jie)質(zhi)的(de)(de)(de)(de)接觸,從(cong)而減輕(qing)腐(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)介(jie)(jie)質(zhi)對密(mi)(mi)(mi)封(feng)(feng)(feng)元(yuan)(yuan)件(jian)(jian)的(de)(de)(de)(de)腐(fu)(fu)蝕(shi)(shi)(shi)(shi)。密(mi)(mi)(mi)封(feng)(feng)(feng)環材料的(de)(de)(de)(de)選取可(ke)以(yi)采用奧(ao)氏體不銹鋼(gang),并在(zai)1 050℃下進行熱處理,防止晶間(jian)腐(fu)(fu)蝕(shi)(shi)(shi)(shi)。
4.由密(mi)封零(ling)件失(shi)效引起的密(mi)封泄漏
機(ji)械(xie)的輔助(zhu)密(mi)(mi)封(feng)(feng)(feng)圈(quan)對(dui)機(ji)械(xie)密(mi)(mi)封(feng)(feng)(feng)有著至關重(zhong)要(yao)(yao)的作用(yong),輔助(zhu)密(mi)(mi)封(feng)(feng)(feng)圈(quan)一般(ban)選用(yong)合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)O形(xing)(xing)圈(quan)。合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)O形(xing)(xing)圈(quan)一旦出(chu)現老化(hua)、永久性變形(xing)(xing)、扭曲及擠出(chu)損傷等情(qing)況時,會(hui)使機(ji)械(xie)密(mi)(mi)封(feng)(feng)(feng)出(chu)現泄(xie)漏。因此合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)O形(xing)(xing)圈(quan)的材質選取(qu)要(yao)(yao)充分考(kao)慮其安(an)全使用(yong)溫度,增加合(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)(jiao)O形(xing)(xing)圈(quan)的截面(mian),用(yong)橡(xiang)(xiang)膠(jiao)(jiao)包覆聚(ju)四氟乙烯等復合(he)(he)材料(liao)作為密(mi)(mi)封(feng)(feng)(feng)圈(quan)的材料(liao),提(ti)高材料(liao)的硬度。在(zai)密(mi)(mi)封(feng)(feng)(feng)圈(quan)安(an)裝時,要(yao)(yao)在(zai)密(mi)(mi)封(feng)(feng)(feng)槽內(nei)涂上潤滑脂。除(chu)了(le)密(mi)(mi)封(feng)(feng)(feng)圈(quan)外,彈簧(huang)、傳動銷(xiao)等零(ling)部件如發生變形(xing)(xing)、斷裂、腐蝕等也(ye)會(hui)導致密(mi)(mi)封(feng)(feng)(feng)泄(xie)漏。在(zai)機(ji)械(xie)密(mi)(mi)封(feng)(feng)(feng)運(yun)行時,也(ye)要(yao)(yao)考(kao)慮彈簧(huang)、傳動銷(xiao)等零(ling)部件的狀(zhuang)態,確(que)保彈簧(huang)、傳動銷(xiao)等零(ling)部件沒有磨(mo)損或(huo)者變形(xing)(xing),使機(ji)械(xie)密(mi)(mi)封(feng)(feng)(feng)正常運(yun)行。