共查询到19条相似文献,搜索用时 436 毫秒
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B302Q球形耐硫变换催化剂于1984年开始研究,首先在中小型化肥厂中串低工艺中应用。最早的中串低工艺分炉内串低变和炉外串低变2种形式。1988年完成了国内第1个中型厂的中串低工艺改造,经理论和电脑模拟,下一步是串2个低变的中低低工艺和3个低变即全低变的工艺。比较后认为中低低本质上仍是中串低,决定下一个工作目标就是重点研究全低变工艺,而不是中低低工艺。该项工作于1989年开始工业试验,至今已有17年的历史,并已成功地在国内外200多套大小不同的装置中工业应用, 相似文献
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我公司变换系统原采用中温变换工艺,后因蒸汽消耗高和反应温度高,改为全低变工艺。全低变工艺于2008年6月投入运行后基本平稳,但2010年出现系统阻力增大的问题,影响了生产负荷提加及后工序生产。 相似文献
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该文介绍了以中中低低变换工艺对全低变工艺进行改造 ,克服了全低变工艺催化剂易失活、阻力上升快和设备腐蚀严重等缺点 ,改造后系统压差 0 0 5MPa ,吨氨蒸汽消耗 2 40kg以下 ,节能效果显著。 相似文献
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在目前的变换工艺中,全低变工艺是较为节能的工艺。利用夹点技术对全低变换热网络进行优化设计,得到的新网络流程不需要外供蒸汽。与第二换热网络相比,减少了设备台数,节省投资费用,目前使用的全低变工艺的能耗还可进一步降低。 相似文献
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主要介绍了天脊集团高平化工有限公司的全低变工艺及该工艺系统自开车以来的运行、改造情况,对变换炉出现的偏温现象及造成的原因进行了分析,提出了预防措施。 相似文献
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Alessandro Marchioni Roberto Tonelli Alessandro Andreani Gaia Francesca Cappiello Matteo Fermi Fabiana Trentacosti Ivana Castaniere Riccardo Fantini Luca Tabbì Dario Andrisani Filippo Gozzi Giulia Bruzzi Linda Manicardi Antonio Moretti Serena Baroncini Anna Valeria Samarelli Massimo Pinelli Giorgio De Santis Alessandro Stefani Daniele Marchioni Francesco Mattioli Enrico Clini 《International journal of molecular sciences》2022,23(5)
Laryngotracheal stenosis (LTS) is a complex and heterogeneous disease whose pathogenesis remains unclear. LTS is considered to be the result of aberrant wound-healing process that leads to fibrotic scarring, originating from different aetiology. Although iatrogenic aetiology is the main cause of subglottic or tracheal stenosis, also autoimmune and infectious diseases may be involved in causing LTS. Furthermore, fibrotic obstruction in the anatomic region under the glottis can also be diagnosed without apparent aetiology after a comprehensive workup; in this case, the pathological process is called idiopathic subglottic stenosis (iSGS). So far, the laryngotracheal scar resulting from airway injury due to different diseases was considered as inert tissue requiring surgical removal to restore airway patency. However, this assumption has recently been revised by regarding the tracheal scarring process as a fibroinflammatory event due to immunological alteration, similar to other fibrotic diseases. Recent acquisitions suggest that different factors, such as growth factors, cytokines, altered fibroblast function and genetic susceptibility, can all interact in a complex way leading to aberrant and fibrotic wound healing after an insult that acts as a trigger. However, also physiological derangement due to LTS could play a role in promoting dysregulated response to laryngo-tracheal mucosal injury, through biomechanical stress and mechanotransduction activation. The aim of this narrative review is to present the state-of-the-art knowledge regarding molecular mechanisms, as well as mechanical and physio-pathological features behind LTS. 相似文献
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本文通过国内第一套以重油为原料生产合成氨的装置中采用中、低变串联新工艺的生产实践,论述了在采用耐硫低变触媒的情况下,中、低变串联新工艺的实现,以及在设计条件下操作的可靠性与先进性,并对触媒运行情况作一介绍和小结. 相似文献
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一次等温CO变换是合并传统的中低和低变为一次变换工艺,总结介绍在泸县化肥厂的生产实践经验,CB-2催化剂的优良性能,一次变换炉结构优化及推广应用前景。 相似文献
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介绍了NB207型低温变换催化剂在改良三触媒流程中的升温还原及应用情况,该催化剂具有机械强度高,、活性稳定性好,低温活性好,还原容易的优点,与B205型催化剂相比,吨氨蒸耗量下降。 相似文献
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变换改为全低变后,变换出口CO含量不稳定、联醇进行负荷调整对造气调节合成氢氮比产生了较大的干扰作用,影响合成氨的稳定生产。本文利用高科技波谱规律分析方法进行调节,将全低变CO、联醇负荷输入微机系统,调节氢氮比,达到提高合成氨产量的目的。 相似文献
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《Journal of the European Ceramic Society》2022,42(2):383-391
Using spark plasma sintering (SPS), >98.5 % dense boron carbide (B4C) samples were made from commercially available and lab-synthesised powders made via a low temperature synthesis (LTS) process. The work showed that the LTS powder can be produced in batches of tens to hundreds of grams whilst maintaining a high purity material with lower levels of residual free carbon (20.6–21.3 wt.% C) than commercially available samples (22.4 wt.% C). The LTS material was seen to exhibit higher hardness values (37.8 GPa) than the commercial grade material (32.5 GPa) despite featuring a coarser average grain size (10.8 μm and 2.4 μm respectively). This is largely thought to be due to the influence of ZrO2 and AlB2 impurities introduced to the material during micronising milling of the powder after synthesis, as opposed to the influence of the materials lower carbon content. 相似文献
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介绍了国内刚开发的煤变压气化技术同已工业化的全低温变换技术配套制取原料气的新工艺在中小型氨厂,甲醇厂技改中的应用前景。 相似文献