共查询到19条相似文献,搜索用时 125 毫秒
1.
针对现有窑法磷酸工艺中磷矿还原率低、热质传递差、结圈堵料等问题,将流态化技术应用于磷矿的还原反应。通过对布风板压降、操作弹性、流化质量、高温流态化还原磷矿反应的研究,考察了4种布风板的性能,并与固定床的热模实验结果进行了比较。实验结果表明:随着气速的增加,直孔布风板的压降以二次函数的形式增长,斜孔布风板则呈现一次函数的关系,且斜孔布风板的阻力损失与床层压降均高于直孔布风板;对于圆面斜孔布风板,曲线压力波动最小,流化质量最好;斜孔布风板的磷矿还原率均高于直孔布风板,说明斜孔孔道有利于磷矿的还原反应;在硅钙摩尔比为3.0、反应温度1 300℃时,圆面斜孔布风板的还原率可达98.26%,且流化床还原磷矿较固定床好。 相似文献
2.
一种用于振动流化床的布风板 总被引:3,自引:0,他引:3
介绍一种用于振动流化床的布风板结构,并对布风板的使用情况作出了分析,根据实际使用要求设计了一种适用于微小颗粒的振动流化床复合型布风板,使用效果良好。 相似文献
3.
4.
1概述
我公司有UG-75/5.3型循环流化床锅炉1台和DG-38/5.3型循环流化床锅炉3台,其布风装置都是水冷布风型,由水冷风室、水冷布风板、风帽和排渣管组成。在锅炉运行中,布风装置经常出现以下故障:风帽磨损快,使用寿命短;布风板易变形,造成布风板上的耐火浇注料剥层脱落,甚至将水冷布风板的水冷壁管拉裂等。公司技术人员在研究了两种循环流化床锅炉的布风装置结构、锅炉运行参数并结合多次检修经验后认为,导致循环流化床锅炉布风装置在锅炉运行中出现以上故障的原因是风帽结构的影响、排渣管结构的影响以及锅炉运行参数的影响。针对以上影响因素,公司作了相应的改进,效果很好。[第一段] 相似文献
5.
6.
提高循环流化床锅炉运行性能的实用技术 总被引:1,自引:0,他引:1
本文针对氮肥厂的工况和燃料特性,研制开发了新循环流化床系列锅炉。该锅炉采用了低倍率循环燃烧技术,蝶形布风板,埋管受热面高位置,中温惯性分离器、L型直吹阀组成返料系统、低烟速防磨、高温炉膛护墙以及旋转切问二次风等技术。 相似文献
7.
李汉廷 《全国造气技术通讯》2005,13(4):25-25
近几年零星的读到不少关于炉箅在布风中的作用的论述,总的印象是:好像炉箅的布风决定着造气炉的命运。甚至有人说:他们设计的炉箅布风效果好得到达巅峰,无可复加了。什么高效炉箅,专用炉箅,样样具有,自我吹,相互捧,比比皆是。炉箅的作用真的这么大吗?我带着这个问题,仔仔细细,反反复复, 相似文献
8.
9.
循环流化床(CFB)锅炉大型化发展的必然结果是炉膛截面尺寸和并联回路的增加,流化床锅炉炉内燃烧和传热过程很大程度上取决于炉内气固流动特性,因此横向气固流动均匀性对锅炉的安全运行具有重要影响。笔者从静态和动态2个方面分析了大型CFB锅炉气固流动横向非均匀性问题。静态非均匀性问题包括布风均匀性和并联回路引起的气固流量沿截面的偏差以及各回路流量分配偏差,在稳定运行条件下不随时间变化。分离器的阻力特性是分离器的重要特性参数,在相同气相流量下,固体颗粒浓度对分离器压降的影响是非单调的,分离器压降随固体颗粒浓度的增加先减小后缓慢增加,理论上并联回路控制方程的解存在多值性,因此多回路并联条件下各分离器循环流率存在偏差。CFB锅炉炉内悬吊屏影响颗粒局部浓度分布,进而影响各分离器固体颗粒循环流率的分配。分离器出口烟道的形式对分离器气固两相的流量分配存在不容忽视的影响。在布风均匀性方面,两侧进风和后墙进风方式均会引起风室不同程度的布风不均。大型CFB锅炉在低负荷运行过程中,存在炉膛两侧床压大幅长周期波动的现象,该现象即为动态气固流动横向非均匀性问题,其产生的主要原因是大截面的布风系统,一次风降低导致的布风失稳以及多回路并联的不均匀性。横向波动数学模型主要是基于气固两相流系统横向波动固有频率的假设,当扰动接近系统固有频率时,会产生较大幅度的横向波动。目前动态非均匀性问题还缺少实验室尺度的深入系统研究,相关机理仍较模糊,是气固流动非均匀性问题的主要研究方向,同时布风不均和密相区气固流动的耦合作用还有待进一步研究。 相似文献
10.
垃圾焚烧管式布风流化床的冷态实验 总被引:3,自引:1,他引:3
在床截面为300mm×300mm、床高为4. 4m的管式布风流化床实验台上,分别对宽筛分下不同颗粒粒度、不同床层高度、不同截面流速、布风的均匀性以及非平衡布风时颗粒流化特性进行实验研究,为未来垃圾衍生燃料的流化燃烧实验提供基础数据。管式布风流化床的开孔方向与夹角大小对床层压降变化影响明显,向下开孔角度越小,动能消耗越大,但床层稳定性能好。随着料层高度增加,各布风管间的布风更趋于平衡,流化的稳定与均匀性能也越好。管组压降失衡时,床层压降不平衡明显增加,波动幅度增大,不稳定性明显高于正常流化状态。 相似文献
11.
针对复合移动床反应器内固体颗粒运动,采用离散单元法模型(DEM)考察布料器分别为扇形开口和矩形开口时,布料器转速和开口对颗粒运动的影响,并基于文献结果论证了本文模型的准确性。模拟结果表明:①对于不同布料器,颗粒在移动床中呈现平推流和汇聚流两种流动形态。②随布料器转速及开口的增加,颗粒质量通量非线性增加。③随布料器转速的增加,下落床径向上颗粒分布更均匀;随布料器开口的增大,下落床径向上颗粒分布范围变大,颗粒分布更均匀;对下落床径向上颗粒分布,布料器扇形开口时分布呈U形、矩形开口时分布呈M形。④沿反应器轴向向下,颗粒分布有均匀化趋势;扇形开口布料器对颗粒分布的离散系数大于1,矩形开口布料器对颗粒分布的离散系数约为0.5。 相似文献
12.
Conditions of the stable performance of gas distributing plates were studied and the effect of plate geometry on gas holdup of uniformly aerated gas-liquid beds was investigated. The ratio of plate holes opened for gas passage was determined as a function of gas hole velocity and critical values of gas hole velocity corresponding to the onset of stable performance of distributing plates were obtained.
Two regimes of bubbling were observed under conditions of stable uniform gas distribution; the regions of their existence being determined by the values of gas flow velocity and distributing plate parameters. Considerable increase of gas holdup was observed in the region of “foam” bubbling compared to the “turbulent” bubbling regime commonly encountered in bubble column reactors. The character of the bed and hence its gas holdup value were affected by the geometry of distributing plates in the “foam” bubbling region while no such effect was observed under “turbulent” bubbling conditions. 相似文献
Two regimes of bubbling were observed under conditions of stable uniform gas distribution; the regions of their existence being determined by the values of gas flow velocity and distributing plate parameters. Considerable increase of gas holdup was observed in the region of “foam” bubbling compared to the “turbulent” bubbling regime commonly encountered in bubble column reactors. The character of the bed and hence its gas holdup value were affected by the geometry of distributing plates in the “foam” bubbling region while no such effect was observed under “turbulent” bubbling conditions. 相似文献
13.
Conditions of the stable performance of gas distributing plates were studied and the effect of plate geometry on gas holdup of uniformly aerated gas-liquid beds was investigated. The ratio of plate holes opened for gas passage was determined as a function of gas hole velocity and critical values of gas hole velocity corresponding to the onset of stable performance of distributing plates were obtained.
Two regimes of bubbling were observed under conditions of stable uniform gas distribution; the regions of their existence being determined by the values of gas flow velocity and distributing plate parameters. Considerable increase of gas holdup was observed in the region of “foam” bubbling compared to the “turbulent” bubbling regime commonly encountered in bubble column reactors. The character of the bed and hence its gas holdup value were affected by the geometry of distributing plates in the “foam” bubbling region while no such effect was observed under “turbulent” bubbling conditions. 相似文献
14.
In the present study, salt granules were dried in a fluidized-bed dryer and suitable technologic parameters of drying operation were obtained. The air distributing structure of fluidized bed dryer was studied and its pressure drop curve was measured. The results indicated that one layer of intertexture net below the air distributing board could produce good air distribution without increase of pressure drop. This kind of structure could also prevent the material from leaking. 相似文献
15.
16.
Seven distributors with different configurations are designed and optimized by constructal approach. Their flow distribution performance and energy dissipation are investigated and compared by computational fluid dynamics (CFD) simulation. The reliability of CFD simulation is verified by experiments on the distributor that has all distributing rectangle channels on a plate. The results show that the symmetry of the distributing channels has decisive influence on the performance of flow distribution. Increasing the generations of channel branching will improve the flow distribution uniformity, but on the other hand increase the energy dissipation. Among all the seven constructal distributors, the distributor that has dichotomy configuration, Y-type junctions and straight intercon-necting channels, is recommended for its better flow distribution performance and less energy dissipation. 相似文献
17.
18.
介绍新型"U"型板溶气气浮装置以及"U"型板的工作原理,重点分析"U"型板溶气气浮对生化污泥的浓缩效果。在不同的污泥负荷、溶气回流比、PAC以及PAM加药量的情况下,进行气浮中试试验,寻找最佳的试验工况。试验结果表明,当污泥负荷为57 kg/(m^2·h)、溶气回流比为35%、PAC加药量为30 mg/L、PAM加药量为8 mg/L时,气浮出泥的污泥含固率能稳定在5.55%左右,"U"型板溶气气浮对生化污泥的浓缩效果很好。这对实际生产中气浮工艺取代二沉池以及重力浓缩池提供了现实可行的指导意义。 相似文献
19.
介绍了微机监控系统在辽化芳烃空压站的应用,系统采用集散式控制系统,以方正微机为上位管理机,以西门子公司的S7—300型PLC为下位控制机,实现自动化控制和管理。 相似文献