CN107915475A - 一种梯度孔高温过滤陶瓷管及其制备方法 - Google Patents

一种梯度孔高温过滤陶瓷管及其制备方法 Download PDF

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CN107915475A
CN107915475A CN201711065578.5A CN201711065578A CN107915475A CN 107915475 A CN107915475 A CN 107915475A CN 201711065578 A CN201711065578 A CN 201711065578A CN 107915475 A CN107915475 A CN 107915475A
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CN107915475B (zh
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徐晓虹
吴建锋
张亚祥
范静
刘星
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Wuhan University of Technology WUT
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Abstract

本发明涉及一种梯度孔高温过滤陶瓷管及其制备方法，所述陶瓷管由内到外由管状支撑体、过渡层及分离膜层组成，并且管状支撑体、过渡层及分离膜层显气孔率和气孔孔径呈梯度分布，显气孔率依次递增，气孔孔径依次递减。本发明提供的梯度孔高温过滤陶瓷管具有使用寿命长、孔径可控、过滤精度高、抗热震性好的优点，对大气环境保护和节约能源具有重要意义。

Description

一种梯度孔高温过滤陶瓷管及其制备方法
技术领域
本发明属于陶瓷技术领域，具体涉及一种用于高温烟气过滤除尘的梯度孔高温过滤陶瓷管及其制备方法。
背景技术
高温陶瓷过滤是一种先进的热气体净化技术，广泛应用于化工、石油、冶金、电力等行业。与常规的旋风除尘、静电除尘等技术相比，该技术更适合去除高温(800℃以上)和腐蚀性工业气体中的粉尘。该技术要求核心陶瓷过滤材料具有优良的热稳定性，除尘效率高、耐腐蚀性能好的优点，能适应极高的工作温度，其除尘机理是当含尘气流通过时，陶瓷过滤管通过惯性碰撞、拦截、扩散作用将粉尘阻挡在其外壁，达到气固分离的目的。
目前，常见的陶瓷过滤材料多为莫来石、氧化铝和碳化硅材质，如美国发明专利《CERAMIC FILTER ELEMENT》(US20110058990A1)公布了一种以碳化硅、莫来石等为原料制备用于高温烟气除尘陶瓷过滤管的方法。《PERMEABILITY AND HIGH TEMPERATURESTRENGTH OF POROUS MULLITE-ALUMINA CERAMICS FOR HOT GAS FILTRATION》一文中介绍了一种氧化铝-莫来石复合多孔陶瓷过滤元件，其显气孔率为43～62％，气孔孔径6～13.8μm，但该过滤管为单层结构，极细粉尘穿过表面后，易造成过滤管污染和堵塞。美国发明专利《CERAMIC FILTER ELEMENT AND METHOD FOR MANUFACTURING A CERAMIC FILTERELEMENT》(US20140346104A1)介绍了一种以莫来石为主要原料制备高温烟气除尘陶瓷过滤管的方法，莫来石陶瓷管机械强度高，但是抗热震性能较差。中国发明专利《碳化硅高温陶瓷过滤管及其制备方法》(CN 101920142B)公开了一种以50～600μm碳化硅骨料为主要原料制备的碳化硅高温陶瓷过滤管，虽然该过滤管的抗热震性能较好，但其为单层结构，平均孔径较大，为40-120μm，因此其对于PM2.5的过滤效果较差；中国发明专利《一种梯度孔隙纯质碳化硅膜管及其制备方法》(CN102633531A)介绍了一种由支撑体层和表面膜层构成的碳化硅质陶瓷过滤管，该过滤管需要在真空、氩气或其它惰性气体保护下烧成，烧成温度高达1500～2400℃，成本极高，且碳化硅颗粒存在高温氧化的缺陷，颗粒粉化后的残渣容易堵塞表面膜层和支撑体层。
发明内容
本发明所要解决的技术问题是针对现有技术中存在的上述不足，提供一种使用寿命长、孔径可控、过滤精度高、抗热震性好的梯度孔高温过滤陶瓷管及其制备方法。
为解决上述技术问题，本发明提供的技术方案是：
提供一种梯度孔高温过滤陶瓷管，所述陶瓷管由内到外由管状支撑体、过渡层及分离膜层组成，并且管状支撑体、过渡层及分离膜层显气孔率和气孔孔径呈梯度分布，显气孔率依次递增，气孔孔径依次递减。
按上述方案，所述管状支撑体、过渡层及分离膜层显气孔率分别为28～38％、36～41％、40～44％，气孔孔径分别为12～45μm、10～16μm、2～8μm，厚度分别为10～20mm、200～500μm、150～200μm。
按上述方案，所述管状支撑体的原料由以下质量份的组分组成：煅烧铝矾土颗粒40～60份，陶瓷结合剂20～50份，造孔剂20～40份；
其中煅烧铝矾土颗粒级配及质量百分比为：1～0.425mm，30～50％；0.425～0.18mm，30～50％；0.18～0.125mm，10～20％；
所述陶瓷结合剂原料及质量百分比例为：高岭土40～50％，滑石40～50％，工业氧化铝10～20％；
所述造孔剂为木炭粉、石墨、碳化硅中的一种或多种按任意比例的混合物。
按上述方案，所述过渡层所用原料包括以下质量份的组分：莫来石纤维(100～200μm)50～80份，煅烧铝矾土粉末10～25份，合成堇青石粉末10～25份，木炭粉5～15份，石墨粉5～10份，硼砂2～8份，熔块5～15份，废玻璃粉5～10份，CMC(羧甲基纤维素)3～5份，STTP(三聚磷酸钠)2～5份；
所述煅烧铝矾土粉末粒径为54～63μm，所述合成堇青石粉末过200～325目筛得到。
按上述方案，所述分离膜层包括以下质量份的组分：莫来石纤维10～40份，煅烧铝矾土粉末30～50份，合成堇青石粉末30～50份，木炭粉5～15份，石墨粉5～10份，硼砂2～8份，熔块5～15份，废玻璃粉5～10份，CMC 3～5份，STTP 2～5份；
所述煅烧铝矾土粉末粒径为44～54μm，所述合成堇青石粉末过200～325目筛得到。
本发明还提供上述梯度孔高温过滤陶瓷管的制备方法，其步骤如下：
1)制备管状支撑体：
a.配料：将煅烧铝矾土颗粒、陶瓷结合剂和造孔剂按比例称取备用；
b.混料与陈腐：将陶瓷结合剂和造孔剂在球磨机中混合球磨1～2h，得到混合粉料，将煅烧铝矾土粗、中、细颗粒表面喷涂PVA溶液后与混合粉料混合搅拌均匀，陈腐24～48h得到混合料；
c.制备陶瓷管坯体：将步骤b陈腐好的混合料利用挤出机挤出得到陶瓷管坯体；
d.制备管状支撑体：将步骤c所得陶瓷管坯体放置于恒温箱中干燥，然后放入高温窑炉中烧结得到管状支撑体；
2)制备梯度孔高温过滤陶瓷管：将过渡层的原料分别加水配制成陶瓷纤维料浆，将分离膜层的原料分别加水配制成分离膜层料浆，在步骤1)所得管状支撑体表面先均匀涂覆一层陶瓷纤维料浆，放入烘箱干燥后再在其上均匀涂覆一层分离膜层料浆，放入烘箱干燥后放入高温窑炉中烧结得到梯度孔高温过滤陶瓷管。
按上述方案，步骤1)b所述PVA溶液添加量为混合料质量的5～10％，PVA溶液质量浓度为2～5％。
按上述方案，步骤1)d所述烧结工艺条件为：以3～5℃/min的速率升温至1300～1360℃，保温1～3h。
优选的是，步骤1)c陶瓷管坯体外径为40～100mm，内径为20～60mm，长度为1000～3000mm。
按上述方案，步骤2)所述陶瓷纤维料浆含水量为30～40％；所述分离膜层料浆含水量为30～40％。
按上述方案，步骤2)所述烧结工艺条件为：以3～5℃/min的速率升温至1080～1120℃，保温1～3h。
本发明通过设计三层结构，使各层的孔隙率、孔径和厚度呈梯度分布，从而赋予过滤管高的过滤效率；通过配方组成设计实现过滤管相组成中莫来石和堇青石的比例调配，从而使过滤管具有优良的抗热震性能和耐腐蚀性能。
经测试，本发明的高温过滤陶瓷管支撑体、过渡层和分离膜层的显气孔率分别≥28％、≥36、≥41％，气孔孔径分别≤45μm、≤16μm、≤8μm；过滤陶瓷管抗折强度≥15.8MPa，1000℃～室温抗热震循环10次不裂，耐酸碱腐蚀性能优良(酸、碱腐蚀质量损失均小于1％)，达到国家标准(GB/T 32978-2016)的要求。该陶瓷过滤管对冶金、电力等行业烟气除尘效率达到99.5％。
本发明的有益效果在于：
1.使用寿命长。本发明提供的陶瓷过滤管为多级梯度孔结构，含尘气体从分离膜层流经支撑体时，较大粒径粉尘被阻挡在分离膜层之外，即使极细微粒穿过分离膜层，也会被过渡层或支撑体捕集，因此进行反吹清灰时，微粒极易脱离过滤管，清洗再生性能好，在800～1000℃的温度下可运行1800～2000h。
2.孔径可控，过滤精度高。本发明采用三种不同粒径的骨料堆积成孔，调整颗粒级配即可控制过滤管孔径，可针对不同行业或过滤要求，合理搭配陶瓷管支撑体、纤维过渡层和分离膜层的孔径，可用于高温烟气中PM2.5的过滤。
3.抗热震性好。本发明的过滤管支撑体、纤维过渡层、分离膜层的热膨胀系数成梯度分布，表面层受到过渡层的压应力，过渡层受到支撑体层的压应力，当过滤管处于急冷急热环境时，表面压应力将抵消部分张应力，从而避免过滤管热震破坏；同时，本发明采用莫来石和堇青石相结合的相组成，进一步保证过滤管具有优良的抗热震性能。
附图说明
图1为本发明实施例1所制备的梯度孔高温过滤陶瓷管断面的SEM图片。
具体实施方式
为使本领域技术人员更好地理解本发明的技术方案，下面结合附图对本发明作进一步详细描述。
实施例1
1)制备过滤管支撑体：
a.原料球磨：将煅烧铝矾土颗粒用球磨机球磨，每隔2h筛分一次，所需颗粒粒径为：1～0.425mm，0.425～0.18mm，0.18～0.125mm；将陶瓷结合剂和造孔剂分别用球磨机球磨1h，过250目筛；
b.混料与陈腐：按各原料所占质量百分比：煅烧铝矾土颗粒50％；陶瓷结合剂30％；外加造孔剂20％，称取原料，将陶瓷结合剂和造孔剂放入球磨机中混合1h，得到混合粉料；将煅烧铝矾土粗、中、细颗粒表面喷涂PVA溶液(质量百分浓度3％)，与上述混合粉料混合搅拌均匀，得到混合料，陈腐24h；PVA的添加量为混合料质量的5％；
所述煅烧铝矾土颗粒级配及质量百分比为：1～0.425mm，30％；0.425～0.18mm，50％；0.18～0.125mm，20％。所述陶瓷结合剂及其质量百分比为：高岭土40％，滑石40％，工业氧化铝20％。所述造孔剂为木炭粉和石墨的混合物，各占50％；
c.制备陶瓷管坯体：将b中陈腐好的混合料利用挤出机挤出外径为80mm，内径为50mm，长度为1000mm的陶瓷管坯体。挤出力为5MPa；
d.坯体干燥与烧成：将陶瓷管坯体放置于90℃恒温箱中干燥12h，干燥后放入梭式窑中以3℃/min的升温速率升至1300℃，保温1h，得到陶瓷过滤管支撑体；
2)制备梯度孔高温过滤陶瓷管：
在陶瓷过滤管支撑体表面均匀涂覆一层陶瓷纤维料浆，得到陶瓷纤维过渡层，放入烘箱中经90℃干燥12h，再在其上均匀涂覆一层分离膜层料浆，膜层厚度150μm，放入烘箱中经100℃干燥15h后放入梭式窑中以3℃/min的升温速率升至1080℃，保温2h，得到梯度孔高温过滤陶瓷管；
所述陶瓷纤维过渡层料浆所用原料及质量百分比分别为：莫来石纤维(100～200μm)50％、煅烧铝矾土颗粒25％、合成堇青石25％、木炭粉10％(外加)、石墨5％(外加)、硼砂5％(外加)、熔块5％(外加)、废玻璃粉5％(外加)、CMC 3％(外加)、STTP 2％(外加)，料浆含水量为总质量的30％。其中煅烧铝矾土颗粒粒径为54～63μm，合成堇青石过200目筛；
所述分离膜层料浆所用原料及质量百分比分别为：莫来石纤维20％、煅烧铝矾土颗粒40％、合成堇青石40％、木炭粉5％(外加)、石墨10％(外加)、硼砂3％(外加)、熔块10％(外加)、废玻璃粉5％(外加)、CMC 3％(外加)、STTP2％(外加)，料浆含水量为总质量的35％。其中煅烧铝矾土颗粒粒径为44～54μm，合成堇青石过200目筛。
经测试，本发明的高温陶瓷过滤管支撑体、过渡层和分离膜层的显气孔率分别为35％、38％和42％，平均孔径尺寸分别为30μm、16μm和5μm；陶瓷过滤管抗折强度为17.5MPa，1000℃～室温抗热震循环10次不裂，酸、碱腐蚀质量损失分别为0.98％和0.82％，达到国家标准(GB/T 32978-2016)的要求。该陶瓷过滤管对冶金、电力等行业烟气除尘效率为99.5％(通过自主研发的高温过滤除尘设备，模拟不同行业烟雾废气进行过滤试验，对过滤前后烟气中的固体颗粒进行分析对比，得到该数据)。结合抗热震实验估测本实施例所得梯度孔高温过滤陶瓷管在800～1000℃的温度下可运行1800～2000h。
如图1所示为本实施例所制备的梯度孔高温过滤陶瓷管断面的SEM图片，可以看出，过滤管断面分层较为明显，由外到内分别为分离膜层、过渡层和支撑体层。
实施例2
1)制备过滤管支撑体：
a.原料球磨：将煅烧铝矾土颗粒用球磨机球磨，每隔3h筛分一次，所需颗粒粒径为：1～0.425mm，0.425～0.18mm，0.18～0.125mm；将陶瓷结合剂和造孔剂分别用球磨机球磨1.5h，过200目筛；
b.混料与陈腐：按各原料所占质量百分比：煅烧铝矾土颗粒40％；陶瓷结合剂30％；外加造孔剂30％，称取原料，将陶瓷结合剂和造孔剂放入球磨机中混合2h，得到混合粉料；将煅烧铝矾土粗、中、细颗粒表面喷涂PVA溶液(质量百分浓度5％)，与上述混合粉料混合搅拌均匀，得到混合料，陈腐30h；PVA的添加量为混合料质量的8％；
所述煅烧铝矾土颗粒级配及质量百分比为：1～0.425mm，40％；0.425～0.18mm，40％；0.18～0.125mm，20％。所述陶瓷结合剂及其质量百分比为：高岭土50％，滑石40％，工业氧化铝10％。所述造孔剂为石墨和碳化硅的混合物，分别占70％和30％；
c.制备陶瓷管坯体：将b中陈腐好的混合料利用挤出机挤出外径为100mm，内径为70mm，长度为1500mm的陶瓷管坯体。挤出力为6MPa；
d.坯体干燥与烧成：将陶瓷管坯体放置于100℃恒温箱中干燥16h，干燥后放入梭式窑中以5℃/min的升温速率升至1340℃，保温1h，得到陶瓷过滤管支撑体；
2)制备梯度孔高温过滤陶瓷管：
在陶瓷过滤管支撑体表面均匀涂覆一层陶瓷纤维料浆，得到陶瓷纤维过渡层，放入烘箱中经100℃干燥15h，再在其上均匀涂覆一层分离膜层料浆，膜层厚度200μm，放入烘箱中经100℃干燥12h后放入梭式窑中以3℃/min的升温速率升至1100℃，保温2h，得到陶瓷过滤管；
所述陶瓷纤维过渡层料浆所用原料及质量百分比分别为：莫来石纤维60％、煅烧铝矾土颗粒25％、合成堇青石15％、木炭粉10％(外加)、石墨5％(外加)、硼砂4％(外加)、熔块10％(外加)、废玻璃粉5％(外加)、CMC5％(外加)、STTP2％(外加)，料浆含水量为总质量的40％。其中煅烧铝矾土颗粒粒径为54～63μm，合成堇青石过250目筛；
所述分离膜层料浆所用原料及质量百分比分别为：莫来石纤维30％、煅烧铝矾土颗粒30％、合成堇青石40％、木炭粉5％(外加)、石墨5％(外加)、硼砂5％(外加)、熔块15％(外加)、废玻璃粉5％(外加)、CMC3％(外加)、STTP2％(外加)，料浆含水量为总质量的36％。其中煅烧铝矾土颗粒粒径为44～54μm，合成堇青石过250目筛。
经测试，本发明的高温陶瓷过滤管支撑体、过渡层和分离膜层的显气孔率分别为26％、38％和40％，平均气孔孔径分别为22μm、15μm和4μm；陶瓷过滤管抗折强度为16MPa，1000℃～室温抗热震循环10次不裂，酸、碱腐蚀质量损失分别为0.94％和0.79％，达到国家标准(GB/T 32978-2016)的要求。该陶瓷过滤管对冶金、电力等行业烟气除尘效率为99.5％。

Claims (10)

1.一种梯度孔高温过滤陶瓷管，其特征在于：所述陶瓷管由内到外由管状支撑体、过渡层及分离膜层组成，并且管状支撑体、过渡层及分离膜层显气孔率和气孔孔径呈梯度分布，显气孔率依次递增，气孔孔径依次递减。
2.根据权利要求1所述的梯度孔高温过滤陶瓷管，其特征在于：所述管状支撑体、过渡层及分离膜层显气孔率分别为28～38％、36～41％、40～44％，气孔孔径分别为12～45μm、10～16μm、2～8μm，厚度分别为10～20mm、200～500μm、150～200μm。
3.根据权利要求1所述的梯度孔高温过滤陶瓷管，其特征在于：所述管状支撑体的原料由以下质量份的组分组成：煅烧铝矾土颗粒40～60份，陶瓷结合剂20～50份，造孔剂20～40份；
其中煅烧铝矾土颗粒级配及质量百分比为：1～0.425mm，30～50％；0.425～0.18mm，30～50％；0.18～0.125mm，10～20％；
所述陶瓷结合剂原料及质量百分比例为：高岭土40～50％，滑石40～50％，工业氧化铝10～20％；
所述造孔剂为木炭粉、石墨、碳化硅中的一种或多种按任意比例的混合物。
4.根据权利要求1所述的梯度孔高温过滤陶瓷管，其特征在于，所述过渡层所用原料包括以下质量份的组分：莫来石纤维50～80份，煅烧铝矾土粉末10～25份，合成堇青石粉末10～25份，木炭粉5～15份，石墨粉5～10份，硼砂2～8份，熔块5～15份，废玻璃粉5～10份，CMC3～5份，STTP 2～5份；
所述煅烧铝矾土粉末粒径为54～63μm，所述合成堇青石粉末过200～325目筛得到。
5.根据权利要求1所述的梯度孔高温过滤陶瓷管，其特征在于：所述分离膜层包括以下质量份的组分：莫来石纤维10～40份，煅烧铝矾土粉末30～50份，合成堇青石粉末30～50份，木炭粉5～15份，石墨粉5～10份，硼砂2～8份，熔块5～15份，废玻璃粉5～10份，CMC 3～5份，STTP 2～5份；
所述煅烧铝矾土粉末粒径为44～54μm，所述合成堇青石粉末过200～325目筛得到。
6.一种权利要求1-5任一所述的梯度孔高温过滤陶瓷管的制备方法，其特征在于步骤如下：
1)制备管状支撑体：
a.配料：将煅烧铝矾土颗粒、陶瓷结合剂和造孔剂按比例称取备用；
b.混料与陈腐：将陶瓷结合剂和造孔剂在球磨机中混合球磨1～2h，得到混合粉料，将煅烧铝矾土粗、中、细颗粒表面喷涂PVA溶液后与混合粉料混合搅拌均匀，陈腐24～48h得到混合料；
c.制备陶瓷管坯体：将步骤b陈腐好的混合料利用挤出机挤出得到陶瓷管坯体；
d.制备管状支撑体：将步骤c所得陶瓷管坯体放置于恒温箱中干燥，然后放入高温窑炉中烧结得到管状支撑体；
2)制备梯度孔高温过滤陶瓷管：将过渡层的原料分别加水配制成陶瓷纤维料浆，将分离膜层的原料分别加水配制成分离膜层料浆，在步骤1)所得管状支撑体表面先均匀涂覆一层陶瓷纤维料浆，放入烘箱干燥后再在其上均匀涂覆一层分离膜层料浆，放入烘箱干燥后放入高温窑炉中烧结得到梯度孔高温过滤陶瓷管。
7.根据权利要求6所述的制备方法，其特征在于步骤1)b所述PVA溶液添加量为混合料质量的5～10％，PVA溶液质量浓度为2～5％。
8.根据权利要求6所述的制备方法，其特征在于步骤1)d所述烧结工艺条件为：以3～5℃/min的速率升温至1300～1360℃，保温1～3h。
9.根据权利要求6所述的制备方法，其特征在于步骤2)所述陶瓷纤维料浆含水量为30～40％；所述分离膜层料浆含水量为30～40％。
10.根据权利要求6所述的制备方法，其特征在于步骤2)所述烧结工艺条件为：以3～5℃/min的速率升温至1080～1120℃，保温1～3h。
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CN111943707A (zh) * 2020-07-24 2020-11-17 武汉理工大学 用于莫来石质陶瓷管的粘结剂及其制备方法和应用方法
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CN115231936B (zh) * 2022-07-12 2023-11-17 山东工业陶瓷研究设计院有限公司 一种复合隔热材料及其制备方法
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CN115894072B (zh) * 2022-12-29 2024-03-08 江苏省宜兴非金属化工机械厂有限公司 一种耐腐蚀陶瓷过滤板及其制备方法

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