一、爆破(po)片概述

  爆破片(pian)的作(zuo)用(yong)是在(zai)設(she)備或(huo)管(guan)道壓(ya)(ya)力(li)突然(ran)升高(gao)尚未引起爆炸前，由于爆破片(pian)兩側壓(ya)(ya)力(li)差達到預定溫度下的預定值時(shi)，即先行破裂，排出設(she)備或(huo)管(guan)道內的高(gao)壓(ya)(ya)介(jie)質。因此爆破片(pian)是防止設(she)備或(huo)管(guan)道破裂的一種安(an)全泄放(fang)裝置。爆破片(pian)安(an)全裝置具(ju)有結(jie)構簡單、靈敏、準確、無泄漏、泄放(fang)能(neng)力(li)強等優點。能(neng)夠在(zai)黏稠、高(gao)溫、低溫、腐蝕的環境下可靠地工作(zuo)，還是超高(gao)壓(ya)(ya)容器(qi)的理想安(an)全裝置。

 爆破(po)片典型圖見(jian)圖6.3.24。

二、爆(bao)破片的(de)分類

  按照結構(gou)型(xing)式(shi)來分類，爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)主(zhu)要(yao)有(you)三種，即平板(ban)型(xing)、正(zheng)拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)和反拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)。平板(ban)型(xing)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)的(de)綜合(he)性(xing)能(neng)較(jiao)差(cha)，主(zhu)要(yao)用于(yu)(yu)低壓(ya)(ya)和超(chao)低壓(ya)(ya)工況，尤其(qi)是大型(xing)料倉。正(zheng)拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)和反拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)的(de)應用場合(he)較(jiao)多。對于(yu)(yu)傳(chuan)統(tong)的(de)正(zheng)拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)，其(qi)工作(zuo)原理是利用材料的(de)拉(la)伸強(qiang)度(du)來控制(zhi)爆(bao)(bao)(bao)破(po)(po)(po)(po)壓(ya)(ya)力，爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)的(de)拱(gong)(gong)(gong)(gong)(gong)(gong)出方向(xiang)與壓(ya)(ya)力作(zuo)用方向(xiang)一致。在使用中(zhong)(zhong)發現，所(suo)有(you)的(de)正(zheng)拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)都存在相同的(de)局(ju)限(xian)：爆(bao)(bao)(bao)破(po)(po)(po)(po)時，爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)碎片(pian)(pian)(pian)會進入泄放(fang)管道；由于(yu)(yu)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)的(de)中(zhong)(zhong)心(xin)厚度(du)被(bei)有(you)意(yi)減(jian)弱，易于(yu)(yu)因疲勞而提(ti)前爆(bao)(bao)(bao)破(po)(po)(po)(po)；操作(zuo)壓(ya)(ya)力不能(neng)超(chao)過(guo)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)最(zui)小(xiao)爆(bao)(bao)(bao)破(po)(po)(po)(po)壓(ya)(ya)力的(de)65％，由此導(dao)致了反拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)的(de)出現。這種爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)利用材料的(de)抗壓(ya)(ya)強(qiang)度(du)來控制(zhi)其(qi)爆(bao)(bao)(bao)破(po)(po)(po)(po)壓(ya)(ya)力，較(jiao)之(zhi)(zhi)傳(chuan)統(tong)的(de)正(zheng)拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)，其(qi)具有(you)抗疲勞性(xing)能(neng)優良、爆(bao)(bao)(bao)破(po)(po)(po)(po)時不產生(sheng)碎片(pian)(pian)(pian)且操作(zuo)壓(ya)(ya)力可達(da)其(qi)最(zui)小(xiao)爆(bao)(bao)(bao)破(po)(po)(po)(po)壓(ya)(ya)力90％以(yi)上的(de)優點。細分之(zhi)(zhi)下，反拱(gong)(gong)(gong)(gong)(gong)(gong)型(xing)爆(bao)(bao)(bao)破(po)(po)(po)(po)片(pian)(pian)(pian)包括反拱(gong)(gong)(gong)(gong)(gong)(gong)刻槽型(xing)、反拱(gong)(gong)(gong)(gong)(gong)(gong)腭齒型(xing)以(yi)及反拱(gong)(gong)(gong)(gong)(gong)(gong)刀架(jia)型(xing)等。

三、爆破片的特點

爆(bao)破片與安全(quan)閥比較，具有(you)結(jie)構簡單、靈敏、可靠(kao)、經濟、無泄漏、適用性強(qiang)等優越性，但也有(you)其局限(xian)性，其特點如(ru)下：

（1）密(mi)封性能(neng)好(hao)，在設備正常工作壓力下能(neng)保持嚴密(mi)不漏。

（2）泄壓(ya)反應迅速，爆破片(pian)的動作(zuo)一般在2～10ms內完成，而安全(quan)閥則(ze)因為機械滯后作(zuo)用，全(quan)部動作(zuo)時間(jian)要高1～2個(ge)數(shu)量級。

（3）對(dui)黏稠性或粉末狀污(wu)物不敏感。即使氣體(ti)中(zhong)含有一定量的(de)污(wu)物也不致影響它的(de)正常動作(zuo)，不像(xiang)安(an)全閥(fa)那(nei)樣，容易黏結或堵塞。

（4）爆(bao)破元件（膜片(pian)）動作后不能復位(wei)，不但設備內介質全部流失(shi)，設備也得(de)中止運行。

（5）動作壓(ya)力不(bu)太穩定，爆破(po)片的爆破(po)壓(ya)力允許偏差(cha)(cha)一(yi)般(ban)都(dou)比(bi)安全閥(fa)的穩定壓(ya)力允許偏差(cha)(cha)大一(yi)些(xie)。

（6）爆破片的使(shi)用壽(shou)命(ming)較短，常(chang)因疲勞而早(zao)期失效。

四(si)、爆破片的適用(yong)場所

（1）獨立的壓力容器和／或壓力管道(dao)系統設(she)有安(an)全(quan)閥(fa)、爆破片(pian)裝置或這二者的組合裝置。

（2）滿足下列情況之一(yi)應優先選用爆破(po)片：

   ①. 壓力有(you)可能迅速上升的；

   ②. 泄放介質(zhi)含有(you)顆(ke)粒、易沉淀、易結晶(jing)、易聚合和介質(zhi)黏度較大；

   ③. 泄放介質有強腐蝕性，使(shi)用安全閥時(shi)其價值(zhi)很高；

   ④. 工(gong)藝介質十分(fen)昂貴或(huo)有劇毒，在(zai)工(gong)作過程(cheng)中不(bu)允許有任何泄漏，應(ying)與(yu)安全閥串聯使用；

   ⑤. 工(gong)作壓力很低或很高(gao)時，選(xuan)用安全閥則其制(zhi)造比較困難(nan)；

   ⑥. 當使用(yong)溫(wen)度較低而(er)影響安全閥工作特性(xing)時(shi)；

   ⑦. 需要較大泄放面積。

（3）對(dui)于一次性使用的(de)管路(lu)系統（如開車吹掃的(de)管路(lu)放空系統），爆(bao)破片的(de)破裂不影響操作和生產的(de)場合，設置爆(bao)破片。

（4）為(wei)減少爆(bao)破(po)片破(po)裂后的工藝介質的損(sun)失，可與安(an)全閥串聯使用。

（5）作為壓力(li)容器的附加安全(quan)設施，可(ke)與安全(quan)閥并(bing)聯使用(yong)，例如爆破片僅用(yong)于火(huo)災情況下(xia)的超壓泄(xie)放。

（6）為(wei)增加異常工(gong)況（如火災等）下的泄放面積，爆破片可并聯使用。

（7）爆(bao)破(po)片不(bu)適(shi)用于經常超壓和溫(wen)度波動很大的場合。

五(wu)、爆破片選用程序

（1）確定被保護(hu)設備或壓力管道系統是否需要設置爆破(po)片。

（2）根據工(gong)藝介質(zhi)和操(cao)作(zuo)條(tiao)件(jian)確定爆(bao)破(po)片(pian)的(de)形式及(ji)材料(liao)。

（3）根(gen)據(ju)被保護管(guan)道系(xi)統的最高壓力(li)及選用的爆破(po)片形式，按標準(zhun)規范確定爆破(po)片的最小(xiao)標定爆破(po)壓力(li)，設計(ji)爆破(po)壓力(li)。

（4）根(gen)據工藝條件、物理參數計算爆破片(pian)的安全泄放(fang)量，選定爆破片(pian)的泄放(fang)面積和(he)泄放(fang)口徑。

（5）填寫爆破(po)片裝置(zhi)規(gui)格書，提供給材料采購專業(ye)，作為訂貨的技(ji)術條件。

六、爆(bao)破片有關標準(zhun)規(gui)范(fan)

  HG/T 20570.3《工藝系統工程設計技(ji)術(shu)規定--爆破(po)片的設置和選用(yong)》

  GB 567《爆(bao)破片(pian)與(yu)爆(bao)破片(pian)裝置》

  GB 12353《拱(gong)型金屬(shu)爆破片裝置分類(lei)與安裝尺(chi)寸》

  GB/T 14566《正拱形金屬爆破(po)片(pian)型(xing)式與參(can)數》

  GB/T 14567《反拱形金屬爆破(po)片型式(shi)與參數》

  GB/T 14568《開(kai)縫形金屬爆破片型式與參數》

  GB/T 16181《爆(bao)破片裝置夾持器(qi)型(xing)式(shi)和外(wai)形(xing)尺寸》

七、安全閥與爆破片性能比較

  安全閥與爆破片(pian)性能比(bi)較見表(biao)6.3.13。