Investigations on increasing safe gas volumetric flow rate through a water trap flame arrester

In the process industries, safety problems may arise when combustible gases are transported through pipes. Therefore, it is necessary to prevent propagation of flame fronts into or through systems, in order to avoid undesired explosions and flashbacks into the production plant. Safety devices which are used in such cases are the flame arresters, e.g. water trap flame arresters. There is a maximum gas flow rate through a water trap flame arrester below which a flashback is unlikely to occur. Based on investigations of the explosion behaviour of bubbles in suspensions of glass spheres, experiments were carried out in a water trap flame arrester of industrial demensions. It is shown that the safe gas volumetric flow rate through a water trap flame arrester can be increased by up to 30% for H₂/air mixtures when glass spheres are added to the liquid in the flame arrester.     

Biologische Abluftreinigung

Biological purification of exhaust gases. The biological purification of exhaust typically employs microorganisms to transform undesired components, particularly those with pronounced odours into innocuous products. Since the activity of these organisms is localized in water, the odiferous substances must be transferred from the air to water. Oxygen must also be supplied to the water for product transformation. Large scale plant for biological purification of waste air from agricultural and industrial operations were introduced in Europe in the early 1960's. Since then this new technology has undergone remarkable developments. The principal plant types are biofilters, dripping units, and bioscrubbing units. In compost production and agriculture there is a current preference for biofilters and drip units, while biofilters and bioscrubbers are preferred in industry. Such plant already largely satisfy demands on purification performance and reliability. Further development in the direction of even higher performance and more compact plant is expected.     

Die verbrennungstechnische Entsorgung eines Chemiebetriebes

Incineration of waste from a chemical facility. Waste from chemical plants includes solids, liquids, gases – all of which require disposal. Solid and liquid wastes can be readily incinerated or deposited in a central plant. Gas purification is the final step of the process, performed at a limited distance from the production plant. If several substances having different properties are involved then thermal waste air purification is appropriate. This paper considers the design concepts of such a thermal waste air purification unit.     

Aufgabenstellung und Konzeptfindung bei einer thermischen Abluftreinigung

Task definition and concept development for a thermal waste air purification system . The present report demonstrates how the properties of waste air and the boundary conditions of the task lead to direct, compelling consequences for the concept, the realization, and the operation of a thermal waste air purification unit. The design of the individual functional groups is always a result of the job criteria and possible influences of other functional groups. The better the adaptation of the plant concept to the demands of the task, the more smoothly the finished plant will run. Very high availability and reliable waste gas quality represent the principal environmentally relevant objectives of such thermal waste gas purification plant. Thermal waste gas/exhaust air purification is presently the most universal procedure for optimum, environmentally appropriate purification.     

Computational Fluid Dynamics Modeling of Combustion of Synthetic Fuel of Thermochemical Heat Recuperation Systems

CFD modeling of the combustion of synthetic fuel formed in the systems of thermochemical recuperation of waste flue gas heat due to steam methane reforming was performed using the ANSYS Fluent software. Scientific justification and validation of the physicomathematical approaches involved the ANSYS Fluent for the problems of modeling the combustion of multicomponent hydrogen-containing gas mixtures. Numerical results were validated against experimental data. A visual comparison of the flame contours obtained by burning syngas at Reynolds numbers of 600, 800, and 1000 was performed. In all cases there is obvious convergence of the results. Change in the temperature of the fuel–air mixture at the entrance to the combustion chamber was found to have no significant effect on the temperature of the combustion products. The obtained results are of practical importance for the design of burner units of high-temperature plants with thermochemical heat recuperation.     

Systematische, überbetriebliche Entsorgung von Abgas- und Abluftströmen aus chemischen Produktionsbetrieben (Ein Beitrag zum Umweltschutz)

Systematic, inter-factory disposal of waste gas and waste air streams from chemical production plants. (A contribution to environmental protection.) Increasing demands upon environmental protection and increasingly stringent legislation necessitated, at the end of the 1960's and the beginning of the 1970's, development of a new technology for the disposal of waste gas and waste air streams from production plants. The special conditions of the Dormagen works of Bayer AG led to a process resulting in the separation of the single waste air streams and their thermal combustion in central combustion plants and power stations. After a development period of several years and the extension of the plants, a standard was reached which permits the operation of even difficult production processes without problems as to waste air.     

Organische Spurenschadstoffe in Brennräumen von Anlagen zur thermischen Entsorgung

Organic trace pollutants in combustion chambers of thermal waste disposal plant. Alongside carbon monoxide, nitrogen oxides, and residual hydrocarbons are “conventional” pollutants from combustion processes, thermal disposal of chlorinated hydrocarbons by combustion may also give rise to organic trace pollutants, such as polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF). Recent advances in our understanding of the kinetics of thermal degradation (pyrolytic, oxidative) in conjunction with information about the degree of backmixing and the residence time characteristics of combustion chambers permit estimation of the influence of temperature, residence time, and oxygen concentration on the formation and degradation of trace pollutants in reals combustion chambers. With conservative assumptions, the maximum parameters required (temperature, residence time) for certain destruction can be obtained. Comparison of the required profile with actual behaviour in combustion chambers demonstrates that the combustion systems used almost exclusively for industrial residue disposal, consisting of a rotary furnace and afterburner chamber, are suitable for disposal of chlorinated wastes providing “normal” operating conditions are maintained.     

Environmental concerns with vinyl medical devices

More and more jurisdictions generate increasingly strict air quality regulations that, almost without exception, include limitations on vinyl chloride. Processors frequently express concerns about their ability to meet environmental and occupational safety VCM limits. To address these concerns, the paper traces residual VCM levels through various stages of conversion from raw PVC resin to finished product storage. Another environmental concern often raised involves the reusability of molded or extruded vinyl devices. While plant regrind is routinely fed back into virgin production and its effect on physical properties is well known, solid waste management considerations increasingly involve postsale reuse of devices, an area not well explored. This paper looks at the reprocessing following long-time storage of devices, not only on physical performance but also on thermal and radiolytic (gamma sterilization) stability.     

Safety Problems in Ozonation Plants

In water treatment plants equipped with large–scale ozonation facilities, specific safety measures must be constantly reviewed and tested. Safety of employees : in high concentrations, ozone becomes a poisonous gas. This requires adequate means for detection of ozone in traces in the ambient air. ventilation and destruction. individual protection Safety of plant and equipment : ozonation has become an essential phase in the treatment process and ozonators must be fitted with safety devices for the detection and rapid control of hazardous conditions.

Experience shows that the measures taken to ensure the safety of employees also improve safety for plant and equipment, and vice versa. The solutions applied demand extra effort at the design stage of the plant, but in return, they result in notable improvements in operating conditions and costs.     

硫酸生产企业的安全评价

强调对硫酸生产企业进行安全评价的重要性和必要性。从介绍安全评价的基本概念入手,对硫酸生产企业的危险及有害因素进行分析和辨识。以一套200 kt/a硫磺制酸装置为例,介绍3种安全评价方法。应用“化工厂危险程度分级”方法得出结论:该硫磺制酸装置的固有危险等级属三级,如果工厂安全管理等级为Ⅱ级,则实际危险等级为中度,通过加强工厂安全管理等级可降低工厂实际危险等级。应用“作业条件危险性评价法”得出结论:硫磺制酸装置除转化单元为“稍有危险”单元外,其它单元都是“可能危险”单元。应用“安全检查表”的检查结果可确定工厂安全管理等级并提出相应的改进措施。     

基于数值模拟的马蹄焰玻璃窑蓄热室热效率研究

蓄热室是马蹄焰玻璃窑余热回收、能源循环再利用的重要设备,它对于降低玻璃窑炉整体能耗有着重要的作用。热效率低的蓄热室不但会造成大量的能源浪费,还可能会减少玻璃窑炉的使用寿命,提高蓄热室的热效率已经成为了玻璃产业亟待解决的问题。为了研究蓄热室参数对热效率的影响规律,首先运用计算流体力学理论和多孔介质模型建立了蓄热室的数值仿真模型,然后结合热平衡分析和气体热力学性质变化规律,建立蓄热室热效率模型,最后运用Fluent对不同参数下蓄热室内部温度场与速度场进行仿真,同时从温度场中采集热效率计算数据并分析各参数对蓄热室热效率的影响规律。结果表明：在保证燃料燃烧充分的前提下,减小助燃空气进口速度、格子体孔隙率、格子砖当量直径有利于增大空气与格子体的传热量,提高蓄热室的热效率,而烟道口进口面积在0.9～1 m²时蓄热室的热效率较高。     

ARGG催化裂化装置辅助燃烧室存在的问题及解决方式

介绍了辅助燃烧室的作用,辅助燃烧室容易出现的问题和异常情况下主风机停机主要处理步骤,了解主风机因各种事故造成停机出现的问题,通过对齐化集团炼油厂催化车间ARCG重油裂解装置辅助燃烧室的改造,解决了因催化剂倒流塞满辅助燃烧室,主风恢复时因阻力过大,不能及时恢复生产,避免了生产停车的事故的发生.     

铁雄冶金硫膏和脱硫废液的制酸实践

介绍了山东铁雄冶金科技集团有限公司硫膏和脱硫废液原有处理工艺状况及存在问题。技术改造后采用富氧燃烧高温裂解及二转二吸干法制酸工艺,将硫膏和脱硫废液制成硫酸产品。该30 kt/a硫膏和脱硫废液制酸装置包括预处理、净化、干吸、转化、尾气处理等工序,装置投产后运行稳定,SO2总转化率大于99.85%,制酸尾气流量7800~8000 m3/h,外排尾气ρ(SO2)<200 mg/m3,硫酸雾(ρ)小于5 mg/m3。净化副产w(H2SO4)2%~4%稀酸2.2~2.6 t/h,在硫铵工序全部回收利用。硫膏和脱硫废液制酸既无害化处理了焦化副产硫膏和脱硫废液,又回收了硫资源,具有良好的经济效益和社会效益。     

Der Entwicklungsstand der Hochtemperatur-Verbrennung und Rauchgasreinigungstechnik — dargestellt an zwei laufenden Bauvorhaben

State of development of high-temperature combustion and flue gas purification — illustrated for two current construction projects. The state of the art in rotary furnace combustion plant is described with the aid of two current construction projects for a chemical plant and for a publicly accessible plant. The concepts of the plant are adapted to the waste material to be disposed of, the energy utilisation system, and disposal of the residual materials. Data for the chemical plant indicate higher concentrations and fluctuations in the flue gas constituents. Flue gas scrubbing is accomplished here by quenching, passage, through two rotary scrubbers, and wet electrofiltration. Scrubber liquid is passed to a company purification plant. In the other case, no waste water may occur. A two-field electrofilter and a two-stage milk of lime washer are employed. Washing liquid is passed to a waste water treatment unit with vacuum evaporation. Special process engineering measures are necessary to maintain pure gas values even in cases of pronounced concentration fluctuations. Household and special waste incineration are discussed increasingly from the viewpoint of NO_x reduction. Possible developments of SCR processes up to use of activated charcoal final purification stages are considered.     

脱硫废液制酸装置电除雾器着火事故分析

介绍了某焦化企业脱硫废液和硫泡沫制酸装置净化工序电除雾器着火的经过和后果,从可燃物和引火源两方面对该着火事故进行了原因分析,并从工艺控制、设备管理和生产操作等方面提出了生产建议。由于原料硫浆在焚烧炉内燃烧不完全,导致大量硫磺及含硫盐类后移进入净化工序,积存在设备及管道内的硫磺粉在电除雾器电场内遭遇火花被引燃而发生着火事故。通过改善原料燃烧效果、增加焚烧炉操作温度监控、设备设置联锁保护和报警装置、及时清理升华硫以及观察稀酸颜色判断焚烧操作状况等措施,实现了制酸装置电除雾器的稳定安全运行。     

Sicherheitsmaßnahmen bei der Lagerung chemischer Produkte. Neue Empfehlungen des Verbandes der Chemischen Industrie

Safety measures in the storage of chemical products. New recommendations from the Federation of the Chemical Industry. Accidents in the storage of chemical products are comparatively rare, but can have enormous consequences for the vicinity if large quantities of materials are involved. Hazards are presented by the possibility of combustion, explosion, and thermal decomposition of the products, by the spread of toxic substances, and by the generation of dangerous decomposition products or contaminated fire-extinguishing water in case of fire. This paper considers the safe storage of explosive substances and protective measures to prevent thermal decomposition, especially of fertilizers. It also reports on the determination of dangerous combustion products and on measures for preventive fire-fighting measures and retention of fire extinguishing water in the case of plant protection agents. New legislation and a number of proposals by the Federation of the Chemical Industry are described.     

Organische Synthese mit mikrostrukturierten Reaktoren

Organic Synthesis with Microstructured Reactors This article describes the chances microstructured reactors offer for chemical plant engineering. This suitability for chemical production is commonly regarded to be the key to the market penetration. Seen in the long term, there is potential that new plants can be equipped with microstructured reactors. Only economic balances, however, which draw up profitability, will open the door to the usage of chemical micro process engineering for plant construction. Main arguments for using microstructured reactors are thus enhanced conversion and selectivity, increased space‐time yields, waste reduction and more safety via small reactor volumes. Credit‐card sized reaction systems allow one to perform the screening of multi‐phase reactions. More prominent, similar screening is carried out for single‐step reactions. Moreover, safe processing with microstructured reactors in the explosive regime enlarges the traditional range of processing. The reaction guidance by microstructured reactors can further influence subsequent processing steps such as product purification and, in this way, can lower the energy costs of processes.     

催化燃烧技术处理石油化工企业含VOCs废气的工艺研究

石油化工企业工艺装置尾气及污水处理场逸散的废气均含有VOCs,其排放给区域空气质量和人体健康带来严重威胁。针对工艺尾气和污水处理场废气的特点,研究了催化燃烧工艺在处理这两类废气时工艺流程及控制方案。对工艺尾气采用碱洗—催化燃烧组合工艺,对污水处理场废气采用脱硫—均化—催化燃烧组合工艺。研究表明,针对上述两种废气,合理选择催化燃烧组合工艺及控制方案,能够有效处理废气中的VOCs组分,且处理后的气体烃类浓度均可达到国家有关标准。     

Anlagen zur Sondermüllverbrennung

Plant for incineration of hazardous waste . Owing to the growth in world population and increasing industrialization, a constant rise in the production of industrial waste is to be anticipated. Thermal conversion of the pollutants leads to products which meet the requirements of “T? Luft” (German technical regulation for air). The conditions required therefore, such as combustion temperature, excess air ratio, retention time, layout of the plant, are explained on the basis of examples. The individual components such as rotary kiln, burners, lances, container feed system, etc. are dealt with, as well as the gas cleaning, slag treatment, and heat recovery systems.     

Einsatz von Biowäschern in der chemischen Produktion

Use of bioscrubbers in the chemical industry. Bioscrubbers are an ecologically and economically interesting alternative to conventional processes like combustion, adsorption and absorption. A brief account of the microbiological and engineering fundamentals of bioscrubbers are given followed by a review of new developments illustrating improvements in process design. The field of application for bioscrubbers is continuously expanding. Two examples of the use of bioscrubbers are discussed. They demonstrate the feasibility of deodorization of slightly contaminated waste gas, as well as the purification of waste gas which is highly loaded with organic substances. The authors describe a new concept for reduction of local hold up of biosuspension at the bioscrubber by integrating the waste water plant as a superior reservoir for fresh biosuspension. The most important advantages of the new concept are as follows: No problems with shut-off time, a better safety in operation, and ready adaptation of the process to changing parameters.