隨著現代窯爐技術(shu)的(de)發展，高(gao)溫窯爐設備的大型化、高效化等技術革新，對爐內(nei)耐火材(cai)料的性能和壽(shou)命(ming)提出了(le)更(geng)高的要求。特別(bie)是對窯爐爐頂耐火材料的要求越來越高，當(dang)下窯(yao)爐頂部結(jie)構，多采用(yong)兩種(zhong)(zhong)砌筑(zhu)方式，一種(zhong)(zhong)使用(yong)楔形耐(nai)火磚對拱砌筑(zhu)，一種(zhong)(zhong)采用(yong)耐(nai)火澆注(zhu)料整體預制澆注(zhu)，整(zheng)體(ti)澆注(zhu)料(liao)的(de)(de)爐頂(ding)，因(yin)澆注(zhu)料(liao)性質的(de)(de)限制，內襯材料(liao)很(hen)容易(yi)剝落甚(shen)至(zhi)大塊坍(tan)塌，影響耐材整(zheng)體(ti)壽命。同時(shi)澆注(zhu)的(de)(de)內襯材料(liao)施工條件要(yao)求高，需要(yao)烘烤才能脫模，相對施工用(yong)時(shi)長，也會影響整(zheng)體(ti)的(de)(de)砌筑施工進度。采用(yong)耐火磚的(de)(de)結構(gou)(gou)，往(wang)往(wang)容易(yi)出現砌筑結構(gou)(gou)不(bu)合理(li)，整(zheng)體(ti)拱頂(ding)受力(li)不(bu)均勻，出現局部掉磚或坍(tan)塌的(de)(de)情況(kuang)，其中(zhong)比如常見的梭式窯拱形頂存在的一些問(wen)題。

一：梭式窯拱形頂耐火(huo)磚(zhuan)承受的應力變化

梭式窯(yao)作為一種(zhong)間(jian)歇(xie)式窯(yao)爐，具有生(sheng)產靈活、操作方便(bian)等特點(dian)，得到(dao)廣泛(fan)應用(yong)；梭式窯(yao)一般最高(gao)使用(yong)溫度可(ke)達1650℃-1750℃之間(jian)，升溫(wen)時(shi)拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)受(shou)熱(re)向窯(yao)體側墻兩(liang)端膨脹(zhang)(zhang)，拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)中(zhong)(zhong)心(xin)磚(zhuan)(zhuan)會承受(shou)來自左右兩(liang)邊拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)的(de)擠壓(ya)(ya)，形成(cheng)(cheng)擠壓(ya)(ya)應力(li)，把(ba)中(zhong)(zhong)心(xin)磚(zhuan)(zhuan)頂(ding)(ding)(ding)起(qi)進入上部(bu)保溫(wen)層(ceng)；停窯(yao)降(jiang)溫(wen)時(shi)，拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)向窯(yao)體兩(liang)端收(shou)縮(suo)(suo)，拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)中(zhong)(zhong)心(xin)磚(zhuan)(zhuan)受(shou)重力(li)下(xia)落，同時(shi)還會受(shou)到左右兩(liang)邊拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)的(de)牽拉作(zuo)用(yong)，形成(cheng)(cheng)拉應力(li)；梭(suo)式窯(yao)間(jian)歇操作(zuo)較(jiao)為頻繁，拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)中(zhong)(zhong)心(xin)磚(zhuan)(zhuan)長期(qi)處在熱(re)脹(zhang)(zhang)冷縮(suo)(suo)狀(zhuang)態下(xia)，壓(ya)(ya)應力(li)和拉應力(li)反(fan)復作(zuo)用(yong)，中(zhong)(zhong)心(xin)磚(zhuan)(zhuan)反(fan)復被頂(ding)(ding)(ding)起(qi)、下(xia)落，應力(li)累積到一定程度，出現裂縫直(zhi)至斷裂，造成(cheng)(cheng)拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)脫落，所以拱(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)中(zhong)(zhong)心(xin)磚(zhuan)(zhuan)要具有更高抗壓(ya)(ya)和抗拉的(de)性能。

二：梭式窯平面結構拱頂磚(zhuan)存(cun)在的缺陷

目前梭式(shi)窯(yao)(yao)一般采用(yong)氧(yang)化鋁(lv)空心(xin)球磚(zhuan)(zhuan)(zhuan)(zhuan)砌筑(zhu)(zhu)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)，具有(you)輕(qing)質高強的(de)(de)(de)作(zuo)用(yong)，但(dan)是現(xian)行的(de)(de)(de)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)結(jie)(jie)構(gou)由拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)和拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)(zhuan)(zhuan)兩(liang)部分(fen)組成(cheng)，拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)具有(you)傾斜支撐面為(wei)(wei)整體結(jie)(jie)構(gou)磚(zhuan)(zhuan)(zhuan)(zhuan)，其(qi)(qi)直接砌筑(zhu)(zhu)于窯(yao)(yao)體及兩(liang)側墻體上作(zuo)為(wei)(wei)對拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)(zhuan)(zhuan)的(de)(de)(de)支撐，拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)(zhuan)(zhuan)由多塊楔形(xing)平(ping)面磚(zhuan)(zhuan)(zhuan)(zhuan)砌筑(zhu)(zhu)成(cheng)橋拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)狀，其(qi)(qi)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)形(xing)的(de)(de)(de)兩(liang)端分(fen)別支撐于拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)傾斜支撐面上。這(zhe)種具有(you)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)形(xing)頂(ding)(ding)(ding)面的(de)(de)(de)砌筑(zhu)(zhu)方(fang)式(shi)，存在(zai)很大(da)(da)程度上拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)下滑(hua)風險，因為(wei)(wei)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)為(wei)(wei)整體結(jie)(jie)構(gou)磚(zhuan)(zhuan)(zhuan)(zhuan)，其(qi)(qi)直接砌筑(zhu)(zhu)在(zai)墻體磚(zhuan)(zhuan)(zhuan)(zhuan)面上，在(zai)水平(ping)方(fang)向上沒有(you)外(wai)(wai)力(li)對其(qi)(qi)進行防滑(hua)限定，其(qi)(qi)在(zai)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)形(xing)頂(ding)(ding)(ding)水平(ping)分(fen)力(li)作(zuo)用(yong)下有(you)被向外(wai)(wai)推(tui)移(yi)的(de)(de)(de)趨勢，加之拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)(zhuan)(zhuan)在(zai)高溫(wen)條(tiao)件(jian)下會因熱(re)而(er)產(chan)生膨(peng)脹(zhang)，這(zhe)就加劇(ju)了拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)(zhuan)(zhuan)對拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)的(de)(de)(de)擠壓(ya)，使(shi)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)所(suo)受的(de)(de)(de)水平(ping)推(tui)力(li)大(da)(da)為(wei)(wei)增加，當該水平(ping)推(tui)力(li)大(da)(da)于拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)所(suo)固有(you)的(de)(de)(de)靜摩擦阻力(li)時，拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)就會發(fa)生沿(yan)墻體磚(zhuan)(zhuan)(zhuan)(zhuan)面的(de)(de)(de)側滑(hua)而(er)導致(zhi)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)下沉開裂，這(zhe)樣(yang)不但(dan)窯(yao)(yao)爐(lu)內的(de)(de)(de)熱(re)量(liang)(liang)會大(da)(da)量(liang)(liang)散(san)失，致(zhi)使(shi)熱(re)損(sun)耗變(bian)大(da)(da)熱(re)效率變(bian)低(di)，而(er)且在(zai)拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)腳(jiao)(jiao)(jiao)磚(zhuan)(zhuan)(zhuan)(zhuan)側滑(hua)移(yi)量(liang)(liang)過大(da)(da)時，還(huan)會產(chan)生拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)(zhuan)(zhuan)掉落，嚴(yan)重(zhong)時還(huan)會發(fa)生拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)塌陷(xian)，嚴(yan)重(zhong)影響窯(yao)(yao)爐(lu)的(de)(de)(de)使(shi)用(yong)壽命和生產(chan)的(de)(de)(de)正常進行。因此這(zhe)種拱(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)頂(ding)(ding)(ding)磚(zhuan)(zhuan)(zhuan)(zhuan)的(de)(de)(de)平(ping)面結(jie)(jie)構(gou)顯然存在(zai)缺陷(xian)，不具有(you)抵抗水平(ping)推(tui)力(li)阻止其(qi)(qi)產(chan)生側滑(hua)的(de)(de)(de)能(neng)力(li)。

三：解決(jue)拱形頂耐火磚側滑、塌陷的辦法(fa)。

①解決高(gao)溫(wen)應力造成的破壞問題。將(jiang)拱頂(ding)中心磚(zhuan)(zhuan)采用重(zhong)質磚(zhuan)(zhuan)替(ti)代氧化鋁空心球磚(zhuan)(zhuan)，體密提高(gao)到2 .9kg/cm3以上，常(chang)溫耐壓強度(du)從10MPa提高到100MPa以上，高溫性能得(de)到較大(da)(da)改善，大(da)(da)大(da)(da)提高拱(gong)頂中心磚抗壓和(he)抗拉能力(li)，降低拱(gong)頂中心磚因應(ying)力(li)作(zuo)用產生斷裂。重質磚同樣(yang)為楔形磚上端(duan)(duan)較大(da)(da)、下端(duan)(duan)較小，大(da)(da)端(duan)(duan)與小端(duan)(duan)的厚度差不小于(yu)10mm，砌筑時重質磚(zhuan)與其相鄰的(de)一側拱頂磚(zhuan)之間(jian)干砌筑；鎖住兩塊磚(zhuan)的(de)大頭，保(bao)證不因重力影響而(er)掉落；兩磚(zhuan)下部之間(jian)留出(chu)縫隙(xi)，縫隙(xi)寬度(du)為1～2mm，拱(gong)頂中心形成一條縱向貫穿的干縫帶。

②解(jie)決拱(gong)(gong)頂磚(zhuan)側滑的(de)(de)辦法，將拱(gong)(gong)頂楔(xie)形磚(zhuan)的(de)(de)平面(mian)結構，改為用榫卯的(de)(de)連接方式，襯磚(zhuan)均通過半(ban)圓凸起和半(ban)圓凹槽咬合在一(yi)起，它能保證對拱(gong)(gong)頂維持良好的(de)(de)連接與(yu)密封(feng)，而且(qie)能結構穩定、壽命長(chang)。