中温井式电阻炉设计

z-1-目录一、设计任务1、专业课程设计题目·················································12、专业课程设计任务及设计技术要求···································1二、炉型的选择······················································1三、炉膛尺寸的确定··················································11、炉膛有效尺寸（排料法）·······································11.1确定炉膛内径D······································11.2确定炉膛有效高度H·······································21.3炉口直径的确定·············································21.4炉口高度的确定··········································3四、炉体结构设计················································31、炉壁设计··················································32、炉底的设计···················································53、炉盖的设计···················································64、炉壳的设计···················································7五、电阻炉功率的确定················································71、炉衬材料蓄热量Q蓄7········································82、加热工件的有效热量Q件·····································93、工件夹具吸热量Q夹·········································104、通过炉衬的散热损失Q散······································105、开启炉门的辐射热损失Q辐···································126、炉子开启时溢气的热损失Q溢··································127、其它散热Q它···········································138、电阻炉热损失总和Q总···································139、计算功率及安装功率··········································13六、技术经济指标计算···············································131、电阻炉热效率················································13z-2-2、电阻炉的空载功率············································143、空炉升温时间················································14七、功率分配与接线方法·············································141、功率分配····················································142、供电电压与接线方法··········································14八、电热元件的设计·················································151、I区························································152、II区··············································163.电热元件引出棒及其套管的设计与选择···························184.热电偶及其保护套管的设计与选择·······························18参考书目·······················································19z-1-一、设计任务1、专业课程设计题目：《中温井式电阻炉设计》2、专业课程设计任务及设计技术要求：1、φ90×1000中碳钢调质用炉.2、每炉装16根3、画出总装图4、画出炉衬图5、画出炉壳图（手工）6、画出电热元件图7、写出设计说明书二、炉型的选择因为工件材料为φ90×1000中碳钢调质用炉对于中碳钢调质最高温度为[870+(30~50)]℃，所以选择中温炉（上限950℃）即可，同时工件为圆棒长轴类工件，因而选择井式炉，并且无需大批量生产、工艺多变，则选择周期式作业。综上所述，选择周期式中温井式电阻炉，最高使用温度950℃。三、炉膛尺寸的确定1、炉膛有效尺寸（排料法）1.1确定炉膛内径D工件尺寸为φ90×1000,装炉量为16根，对长轴类工件，工件间隙要大于或等于工件直径；工件与料筐的间隙取100~200mm。炉膛的有效高度150~250mm排料法如图所示则：根据几何关系，每根工件最小距离取90mm，则可以计算出D=2×90×d=890mmz-2-D效=d+2×100—200=1100又因炉壁内径比料筐大200~300mm故取：D砌=1500mm查表得可用砌墙砖为BSL·427·467(A=168,B=190.8,R=765,r=675)型轻质粘土扇形砖。由该砖围成的炉体的弧长为：S=D=3.14×1500=4710mm砖的块数为：4710÷168=28.04块，取整后N=28对D进行修正得：D砌=28×168÷3.14=1500mm，取D砌=1500mm1.2确定炉膛有效高度H由经验公式可以得知，井式炉炉膛有效高度H应为所加热元件（或者料筐）的长度的基础上加0.1~0.3m。H效=1000+200=1200mmH=H效+250=1450mm由于电阻炉采用三相供电，放置电热元件的搁砖应为3n层，H砌=3n×(65+2)+67,n=6.88.取整后取n=7再将n=7代入上式，得H砌=1474mm选用代号为SND-427-09的扇形搁砖每层搁砖数目为N=D砌÷50=94.2，取整为94块。搁砖总数n=94×21=1976块1.3炉口直径的确定D效=110mm，由于炉口用斜行楔形砖8SL.427.498故有，D效=74×N将D效=1100mm代入，得N=46.7，取整后N=47，再将N=47代回上式，则得到D炉口=1107mm。扇形砖选择8SL。427.077D炉口=166×N得D=20.8取=21D效=1100mmD砌=1500mm砖的块数:N=22修正后：D砌=1500mm搁砖21层H砌=1474mm每层搁砖数目：N=94搁砖总数n=1976块到D炉口=1107mm。z-3-1.4炉口高度的确定按一般的设计原则，炉口可由斜行楔形砖和2层直行砖堆砌而成。故H炉口=（65+2）×3+32=233mm四、炉体结构设计炉体包括炉壁、炉底、炉盖、炉壳几部分。炉体通常用耐火层和保温层构成，尺寸与炉膛砌筑尺寸有关。设计时应满足下列要求：（1）确定砌体的厚度尺寸要满足强度要求，并应与耐火砖、隔热保温砖的尺寸相吻合；（2）为了减少热损失和缩短升温时间，在满足强度要求的前提下，应尽量选用轻质耐火材料；（3）耐火、隔热保温材料的使用温度不能超过允许温度，否则会降低使用寿命；（4）要保证炉壳表面温升小于60℃，否则会增大热损失，使环境温度升高，导致劳动条件恶化。1、炉壁设计炉壁厚度可采用计算方法确定，下图为井式炉炉壁二层结构，第Ⅰ层为耐火层，其厚度一般为90mm，采用轻质粘土砖RNG-0.6；第Ⅱ层为B级硅藻土砖+耐火纤维，其厚度取标准砖115mm，第Ⅲ层为保温层，采用B级硅藻土砖架构中间填充矿渣棉，其厚度设计为xmm。在稳定传热时，对各炉衬热流密度相同。根据课本的公式结合查表，可得：N=21H炉口=233mmz-4-两层炉寸q=(t3-t0)，由设计参考书温升50℃，则炉壁温度60℃，室温20℃是αƩ=12.17W/(m2*0C)所以q=12.17×40=486.8W/(m2*0C)RNG-0.6型轻质粘土砖：1密度31600kgm；热导率310.1650.1910twmC均；比热容31C0.8360.26310tgKJKC均。硅酸铝纤维密度ρ2=120kg/m3；热导率λ2=0.032+0.21×（10—3t均）*2W/(m*0C)；比热容C2=1.1KJ/（kg*0C）。由2221111111111[2(0.5)tbbttqSb代入数据得：)50.64109.0950165.0194.05.0(194.02165.00.001×0.2319501010165.023322t=820℃λm=0.032+0.21×{（820+50）／2×1000}*2=0.0727w／m.℃S2=1／486.6×0.0727×(820-60)=113.5mm取S2=115mm190SmmS2=1150t=20℃t3=60℃1t=950℃2t=820℃z-5-2、炉底的设计炉底结构通常是在炉底壳部的钢板上用珍珠岩砖或硅藻土砖砌成方格子，各格子中填充蛭石粉。然后，在平铺二层重质粘土砖。炉底砖的厚度尺寸可参照炉壁的厚度尺寸，一般为230~690mm。由于要承受炉内工件的压力，且装出炉有冲击的作用。故炉底板要求又较高强度。由底至上，第一层为膨胀蛭石粉和硅藻土砖复合层，第二层，第三层为重粘土砖。结构：厚度∕mm材料：砌砖型号：Ⅰ115膨胀蛭石粉+硅藻土砖B级BSL·427·280Ⅱ67重粘土砖RNG-1.3BSL·427·013Ⅲ67重粘土砖RNG-1.3BSL·427·0133、炉盖的设计炉顶的结构有平顶、拱顶和悬顶三种。当炉子的宽度为600~3000mm时，可采用拱顶，拱角可用60°和90°，其中使用最多的是60°，这种拱顶称为标准t3=60℃S2=115z-6-拱顶。拱顶是炉子最容易损坏的部位，拱顶受热时耐火砖发生膨胀，造成砌拱顶时，为了减少拱顶向两侧的压力，应尽量采用轻质的楔形砖与标准直角砖混合砌筑。设计条件：炉膛温度950℃，壳体温度60℃，室温20℃。上层采用普通硅酸铝纤维，下层用轻质粘土砖。结构厚度(mm)材料型号第一层180普通硅酸铝纤维第二层115轻质粘土砖RNG-0.6BS·427·444、炉壳的设计炉壳的尺寸取决于炉子砌体的尺寸，炉子的砌体包在炉壳之内。炉体框架要承受砌体和工件的重量以及工作时所产生的其它附加外力。因此，框架要有足够用的强度，框架和炉壳一般通过焊接成型，构成整个整体，以保证强度和密封性的要求。炉壳一般用3~5mm的Q235钢板，炉底用6~8mm的厚板，井式炉炉壳圈一般用6.3或7号角钢制作。综上所述，炉壳采用5mm厚的Q235钢板，炉底选用8mm厚的钢板，炉壳圈炉盖结构图第一层第二层z-7-选用三根7号角钢均匀分布，两根7号角钢横向分布，炉底五根槽钢通过焊接而成。五、电阻炉功率的确定电阻炉的功率大小与炉膛容积、炉子结构、炉子所要求的生产率和升温时间等因素