化工离心泵机械密封失效原因探讨

探究化工离心泵机械密封失效原因,对化工离心泵运行过程中常见机封失效问题进行深入解读,重点阐述腐蚀导致的密封失效.基于此,梳理应对化工离心泵机械密封失效的对策,从防腐蚀、防摩擦、人为因素、确保安装精度等视角解决化工离心泵机械密封失效,为化工生产提供有力保障.     

氢氯化反应器的失效分析及改进

由于生产负荷增加,导致四川鸿鹤精细化工有限责任公司氢氯化反应器酸腐蚀失效,介绍了该设备失效形态,分析认为该设备失效原因主要有:原料气特性的改变,气体分布器能力不足,设备本身设计制作质量的欠缺,提出了相应的改进措施.经改进后,设备运行稳定,且能满足生产负荷需求.     

浅析原料气过滤分离器快开盲板唇形圈失效原因

针对某高含硫气田原料气过滤器快开盲板唇形圈多次失效泄漏,通过对唇形圈进行外观检查、红外光谱分析、硬度测试、NACE标准测试和模拟工况测试,结合实际生产操作,分析失效原因,得出制造缺陷是导致唇形圈泄漏的主要因素,材质的不适应性和频繁升降压操作促进了失效.     

鸭儿峡油田抽油杆失效机理与治理对策研究

鸭儿峡油田部分油井杆柱失效状况频发,致使油田井下作业频繁,严重影响了油田正常生产。统计发现失效原因主要为偏磨失效、腐蚀失效、疲劳损伤导致的抽油杆断脱。结合对91口杆柱失效井的分析发现造成偏磨的主要原因有杆柱中和点较高、井眼轨迹变化复杂、生产参数不合理等;引起腐蚀的主要原因是地层水对抽油杆腐蚀情况加剧。结合生产实际,提出了管杆柱底部集中加重、优化杆柱结构使中和点下移、偏磨段连续扶正、确定合理生产参数减少惯性载荷等综合配套防治技术。现场应用表明提出的方法可有效改善鸭儿峡油田杆柱失效现象。     

石墨压力容器研究进展

石墨压力容器具有耐高温、高导热及耐酸碱腐蚀等特点,常应用于特定化工产品的生产、贮存及运输.石墨压力容器属于特种设备,一旦其在使用过程中失效,将会产生严重后果.基于相关的研究现状,从石墨压力容器的制造、失效及应用三个方面综述了石墨压力容器的研究进展.     

反应器进料泵机械密封失效分析及改进

通过对聚乙烯装置反应器进料泵机械密封失效过程的讲述,对失效的原因进行了分析.结合反应器进料泵的工作条件,根据机械密封和干气密封的自身特点,提出对反应器进料泵机械密封的改进措施,为今后装置的稳定生产奠定了基础.     

RFCC装置外取热器管束失效分析与预防

介绍了600kt/a重油催化裂化(RFCC)装置气控式外取热器的结构特点,并结合外取热器在生产应用中出现的问题,从结构设计、设备制造、运行工况方面分析失效原因,提出了预防失效的措施.     

从套管弯曲角度认识电泵机组失效原因及预防措施

本文针对套管弯曲对电泵生产造成的影响进行了分析,结合作业生产现场实例,分别从以下两个方面阐述了电泵机组失效原因和预防措施。弯曲套管造成电泵机组失效机理分析;弯曲套管造成电泵机组失效的两种基本类型。     

液硫泵的失效分析

为保证液硫泵的正常运转、整套硫磺回收装置的平稳生产,通过对液硫泵进行事故树分析,得出液硫泵失效原因。结合现场液硫泵的使用实际,从泵体失效、轴承失效和密封失效等三个方面分析原因,并提出了相应的优化措施。     

橡胶密封件常见失效形式分析

密封失效是造成非计划停车的主要原因,分析橡胶密封件的失效问题对于机械设备的防漏、治漏,提高设备利用率和生产效率有重要的意义。本文总结了橡胶密封件在使用中常见的失效形式,分析了失效形成的原因,给出了相应的解决办法,为橡胶密封件的可靠使用提供了有益的参考。     

THE DESIGN AND OPTIMIZATION OF AN INDUSTRIAL DRYER FOR SULTANA RAISINS

A mathematical model of a tunnel dryer for sultana grapes is presented and applied for the determination of size and optimal operating conditions of the dryer. The optimum condition is given by the minimization of heat consumption, expressed as the ratio of thermal load to production, with some constraints regarding the production rate of the dryer and the maximum permissible air temperature. The optimization variables are temperature and humidity of the drying air, and product loading thickness on the trays. The optimum condition requires the operation of the dryer on the maximum permissible air humidity, which corresponds to a high degree of recirculation of exhaust air. This can be accomplished using automatic control of fresh air and humid air inlet and exhaust dampers along the length of the dryer, during the entire drying cycle.     

THE DESIGN AND OPTIMIZATION OF AN INDUSTRIAL DRYER FOR SULTANA RAISINS

A mathematical model of a tunnel dryer for sultana grapes is presented and applied for the determination of size and optimal operating conditions of the dryer. The optimum condition is given by the minimization of heat consumption, expressed as the ratio of thermal load to production, with some constraints regarding the production rate of the dryer and the maximum permissible air temperature. The optimization variables are temperature and humidity of the drying air, and product loading thickness on the trays. The optimum condition requires the operation of the dryer on the maximum permissible air humidity, which corresponds to a high degree of recirculation of exhaust air. This can be accomplished using automatic control of fresh air and humid air inlet and exhaust dampers along the length of the dryer, during the entire drying cycle.     

Modeling and Optimization of a Tunnel Crape Dryer

A mathematical model of a tunnel dryer for the dehydration of grapes is presented and applied to the determination of optimal operating conditions of the dryer. The dryer is of semi-batch structure, operating with trucks and trays. The cycle period is determined by meeting appropriate quality specifications for the final product. The nominal conditions were evaluated bv suitably minimizing. the total fuel demand, expressed as fuel consumption to production capacity, under some constraints regarding the production rate of the dryer and the maximum permissible air temperature. An nominal air humidity value was evaluated suggesting a minimum cycle period value for the production capacity and fuel demand. The nominal conditions required operation of the dryer on the maximum permissible air temperature. The optimum operation was evaluated by maximizing the total profit resulting from the operation of the dryer. The optimization variables were temperature and humidity of the drying air stream. A charteristic case study of industrial grape was included to illustrate the effectiveness of the proposed approach.     

Modeling and Optimization of a Tunnel Crape Dryer

ABSTRACT

A mathematical model of a tunnel dryer for the dehydration of grapes is presented and applied to the determination of optimal operating conditions of the dryer. The dryer is of semi-batch structure, operating with trucks and trays. The cycle period is determined by meeting appropriate quality specifications for the final product. The nominal conditions were evaluated bv suitably minimizing. the total fuel demand, expressed as fuel consumption to production capacity, under some constraints regarding the production rate of the dryer and the maximum permissible air temperature. An nominal air humidity value was evaluated suggesting a minimum cycle period value for the production capacity and fuel demand. The nominal conditions required operation of the dryer on the maximum permissible air temperature. The optimum operation was evaluated by maximizing the total profit resulting from the operation of the dryer. The optimization variables were temperature and humidity of the drying air stream. A charteristic case study of industrial grape was included to illustrate the effectiveness of the proposed approach.     

Investigations on Drying of Salt Granules and the Air Distributing System of Fluidized Bed∗

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.     

5HJD-1玉米秸秆穿流干燥机的设计研究

介绍了玉米秸秆穿流干燥机的工艺流程、主要设计参数。生产能力为1t·h^-1，设计采用组合干燥工艺，保证干燥品质，节能显著，使秸秆一次降至最佳水分。     

Investigation of Air Flow Distribution in Small-Scale Food Products Dryer

Experimental and numerical investigations showed that the air flow velocity distribution between the shelves with identical inlet cross sections is nonuniform; in the gaps between the shelves located in the bottom part of the dryer the velocity is rather high and in the gaps between the shelves located in the middle and at the top of the dryer the velocity is low. A nonuniform air flow distribution causes unequal drying of the product; therefore, the position of shelves with the products must be periodically changed; that is, operation of the dryer is not optimal. It was revealed during numerical investigations that the use of variable inlet cross sections between the shelves gives more uniform air flow distribution. Numerically obtained air flow velocity distribution results between the shelves with the use of variable inlet cross sections were also justified experimentally.     

Optimization study of soybean intermittent drying in fixed-bed drying technology

Intermittent drying of materials is an alternative operation that aims at reducing energy consumption, improve the preservation of dried products or decrease effective drying time. Intermittent drying supplies the system with time-varying input air properties that are opposite to traditional operations, where air properties are constant at the dryer inlet. The major objective of this study is to establish the most satisfactory patterns of air temperature and velocity modulation at the dryer entrance to reduce energy consumption. This optimization study was based on a heterogeneous model for the drying of grains in fixed bed validated with experimental data. Intermittent and conventional operation experiments were conducted using equal energy consumption, and the influence of air temperature and velocity modulation on the drying rates related to the percentage of evaporated water were assessed. Results indicated that higher drying rates can be achieved under intermittent operation, and the validated model based on these results could reasonably predict temperature and moisture content profiles. Simulations pointed out that the best modulation patterns of air properties is a function of a variety of system conditions such as initial temperature and moisture content of both soybean and drying air. However, a tendency to reduce energy consumption was observed when the system operation is initially at high temperature and constantly at low velocity.     

循环流化床中C类颗粒连续干燥的研究

循环流化床(CFB)作为一种新兴反应器,其结构简单、气固接触效率高、处理量大,成为气固二相干燥应用研究的新方向.文中在自建的循环流化床(内径0.104 m×高2.35 m)内,以玉米淀粉(dp=8 μm,ρp=800 kg/m3)为C类颗粒,进行了连续干燥.实验初步研究了进料速率、进风温度及气速等操作参数对淀粉平均停留...