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發布時(shi)間:2021-12-08 11:06:29 人氣:140538 來源(yuan):
分析大冶機械密封泄漏原因,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,找出大冶機械密封泄漏原因,以此為依據,選擇正確的大冶機械密封。下面是大冶機械密封常見的泄漏現象及原因分析
1. 機械磨損
大冶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,導致大冶機械密封泄漏。這種大冶機械密封泄漏可根據大冶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,說明大冶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。如果大冶機械密封副磨損痕跡很深,則有可能(neng)是傳動軸(zhou)轉動時密封副出(chu)現分(fen)離,有大(da)顆粒(li)物質嵌(qian)入軟質碳(tan)端(duan)面(mian),此時可用硬(ying)質材料作為密封副材料。
2. 由(you)熱(re)損傷引起的密封(feng)泄漏
機械產生(sheng)過大的熱量往(wang)往(wang)造成機械密封副(fu)變(bian)形、熱裂(lie)或皰疤(ba),引起泄漏(lou)。
熱裂主要(yao)是(shi)機(ji)(ji)(ji)械密封(feng)(feng)在(zai)(zai)干摩擦或(huo)冷(leng)卻系統(tong)發生中斷(duan)等情況下,造(zao)成機(ji)(ji)(ji)械密封(feng)(feng)在(zai)(zai)短時間內(nei)承受超負荷(he)熱量而出現密封(feng)(feng)環表面徑向(xiang)裂紋。由于(yu)熱裂往往引起密封(feng)(feng)環磨損(sun)加(jia)劇,造(zao)成大(da)量的(de)(de)泄漏,所以(yi)在(zai)(zai)設(she)計機(ji)(ji)(ji)械密封(feng)(feng)時要(yao)充分考慮機(ji)(ji)(ji)械材(cai)料的(de)(de)物(wu)理性(xing)質(zhi),并(bing)要(yao)根據機(ji)(ji)(ji)械材(cai)質(zhi)設(she)定(ding)特定(ding)的(de)(de)運轉條(tiao)件。皰疤主要(yao)是(shi)由于(yu)碳石墨導致(zhi)粘結(jie)劑(ji)被擠出,出現密封(feng)(feng)泄漏。由于(yu)介(jie)質(zhi)的(de)(de)潤滑性(xing)、操作溫(wen)度(du)(du)、線速度(du)(du)、配對材(cai)料組合等因素的(de)(de)影響都會使機(ji)(ji)(ji)械密封(feng)(feng)產生大(da)量熱能,所以(yi)為了使機(ji)(ji)(ji)械密封(feng)(feng)摩擦熱能及時散發,改變端面面積(ji)比、減(jian)少(shao)載荷(he)、靜止(zhi)型密封(feng)(feng)并(bing)加(jia)導流(liu)套都能較好地改善密封(feng)(feng)的(de)(de)散熱條(tiao)件,保證機(ji)(ji)(ji)械密封(feng)(feng)的(de)(de)正常運行(xing)。
3. 由腐蝕引起的密封泄漏
機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)的(de)(de)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)是(shi)(shi)(shi)引起機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)泄漏最主(zhu)要(yao)原(yuan)因之一,一般有(you)化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)和電(dian)(dian)(dian)化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)。化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)主(zhu)要(yao)是(shi)(shi)(shi)由于機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)長時(shi)間與腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)性(xing)(xing)介質(zhi)(zhi)接觸(chu)引起的(de)(de)。這種(zhong)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)對(dui)(dui)(dui)機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)影響較(jiao)大(da),甚(shen)至會(hui)導致(zhi)機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)金屬晶界的(de)(de)破(po)壞或(huo)斷裂。電(dian)(dian)(dian)化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)主(zhu)要(yao)是(shi)(shi)(shi)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)環兩種(zhong)金屬在(zai)電(dian)(dian)(dian)介質(zhi)(zhi)溶液(ye)中產生電(dian)(dian)(dian)位差,導致(zhi)機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)產生電(dian)(dian)(dian)池(chi)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)。不管是(shi)(shi)(shi)化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)還是(shi)(shi)(shi)電(dian)(dian)(dian)化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)對(dui)(dui)(dui)機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)都有(you)很大(da)的(de)(de)影響,所以(yi)在(zai)機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)材料(liao)選取(qu)上(shang)要(yao)考慮密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)元(yuan)件的(de)(de)精(jing)密(mi)(mi)(mi)(mi)(mi)性(xing)(xing),選擇比主(zhu)機(ji)(ji)更耐腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)的(de)(de)材料(liao)。機(ji)(ji)械(xie)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)速度(du)的(de)(de)快(kuai)(kuai)慢與壓(ya)力(li)、溫度(du)和滑動(dong)速度(du)都有(you)密(mi)(mi)(mi)(mi)(mi)切(qie)的(de)(de)關系。當(dang)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)元(yuan)件所承受的(de)(de)壓(ya)力(li)增大(da)、溫度(du)升高、滑動(dong)速度(du)加快(kuai)(kuai)時(shi),密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)元(yuan)件的(de)(de)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)速度(du)也(ye)會(hui)加快(kuai)(kuai)。針(zhen)對(dui)(dui)(dui)這些因素,采(cai)取(qu)雙端面(mian)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)可以(yi)減(jian)少密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)元(yuan)件的(de)(de)零件與腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)性(xing)(xing)介質(zhi)(zhi)的(de)(de)接觸(chu),從而(er)減(jian)輕腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)性(xing)(xing)介質(zhi)(zhi)對(dui)(dui)(dui)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)元(yuan)件的(de)(de)腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)。密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)環材料(liao)的(de)(de)選取(qu)可以(yi)采(cai)用奧氏體不銹鋼,并在(zai)1 050℃下進行熱(re)處(chu)理,防止晶間腐(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)(shi)。
4. 由密封零件失效引起的密封泄漏
機械的輔(fu)助密(mi)(mi)封(feng)圈(quan)(quan)(quan)對機械密(mi)(mi)封(feng)有著至關重要(yao)的作用,輔(fu)助密(mi)(mi)封(feng)圈(quan)(quan)(quan)一(yi)般(ban)選用合(he)(he)(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)O形(xing)(xing)圈(quan)(quan)(quan)。合(he)(he)(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)O形(xing)(xing)圈(quan)(quan)(quan)一(yi)旦出現老化(hua)、永(yong)久性變(bian)形(xing)(xing)、扭(niu)曲及擠出損傷(shang)等(deng)情況(kuang)時(shi),會(hui)使機械密(mi)(mi)封(feng)出現泄漏。因此合(he)(he)(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)O形(xing)(xing)圈(quan)(quan)(quan)的材質選取(qu)要(yao)充(chong)分考(kao)慮(lv)其安全使用溫(wen)度,增加合(he)(he)(he)(he)成(cheng)橡(xiang)(xiang)膠(jiao)O形(xing)(xing)圈(quan)(quan)(quan)的截面,用橡(xiang)(xiang)膠(jiao)包覆聚四氟乙烯(xi)等(deng)復合(he)(he)(he)(he)材料作為密(mi)(mi)封(feng)圈(quan)(quan)(quan)的材料,提高(gao)材料的硬度。在(zai)(zai)密(mi)(mi)封(feng)圈(quan)(quan)(quan)安裝時(shi),要(yao)在(zai)(zai)密(mi)(mi)封(feng)槽內涂上(shang)潤滑脂。除了密(mi)(mi)封(feng)圈(quan)(quan)(quan)外(wai),彈簧、傳(chuan)動(dong)(dong)銷等(deng)零部件(jian)如發生變(bian)形(xing)(xing)、斷裂、腐蝕等(deng)也會(hui)導(dao)致密(mi)(mi)封(feng)泄漏。在(zai)(zai)機械密(mi)(mi)封(feng)運(yun)行時(shi),也要(yao)考(kao)慮(lv)彈簧、傳(chuan)動(dong)(dong)銷等(deng)零部件(jian)的狀態,確(que)保彈簧、傳(chuan)動(dong)(dong)銷等(deng)零部件(jian)沒有磨損或(huo)者變(bian)形(xing)(xing),使機械密(mi)(mi)封(feng)正常運(yun)行。