Studies on High Density Polyethylene in the Far-field Region in Ultrasonic Welding of Plastics

Polyethylene (PE) is an extremely versatile plastic and has the largest sales turnover than other plastics. With new uses for PE, researchers continue to find innovative technologies to process and join the material. Ultrasonic welding is one such process that is rapidly emerging as a major joining process for thermoplastics because of its reliability, ease of operation, fastness, and economic feasibility. Amorphous polymers are ideal materials for ultrasonic welding, but semicrystalline polymers are difficult to weld in the far-field region. This paper deals with the far field welding of semicrystalline polymer/high-density polyethylene (HDPE). The temperature distribution has been modeled for varying lengths of the specimen using Ansys to predict the temperature spikes, which can be related to the performance of the joints achieved. Experimental work studied the temperature at the joint interface and the variation in tensile strength for different lengths of the specimen.     

Comparison of solvent performance for CO2 capture from coal-derived flue gas: A pilot scale study

The performance of a proprietary solvent (CAER-B2), an amine-carbonate blend, for the absorption of CO₂ from coal-derived flue gas is evaluated and compared with state-of-the-art 30 wt% monoethanolamine (MEA) under similar experimental conditions in a 0.1 MWth pilot plant. The evaluation was done by comparing the carbon capture efficiency, the overall mass transfer rates, and the energy of regeneration of the solvents. For similar carbon loadings of the solvents in the scrubber, comparable mass transfer rates were obtained. The rich loading obtained for the blend was 0.50 mol CO₂/mol amine compared to 0.44 mol CO₂/mol amine for MEA. The energy of regeneration for the blend was about 10% lower than that of 30 wt% MEA. At optimum conditions, the blend shows promise in reducing the energy penalty associated with using industry standard, MEA, as a solvent for CO₂ capture.     

The effect of scale and interfacial tension on liquid–liquid dispersion in in-line Silverson rotor–stator mixers

The effect of scale, processing conditions, interfacial tension and viscosity of the dispersed phase on power draw and drop size distributions in three in-line Silverson rotor–stator mixers was investigated with the aim to determine the most appropriate scaling up parameter. The largest mixer was a factory scale device, whilst the smallest was a laboratory scale mixer. All the mixers were geometrically similar and were fitted with double rotors and standard double emulsor stators. 1 wt.% silicone oils with viscosities of 9.4 mPa s and 339 mPa s in aqueous solutions of surfactant or ethanol were emulsified in single and multiple pass modes. The effect of rotor speed, flow rate, dispersed phase viscosity, interfacial tension and scale on drop size distributions was investigated.     

Internal configurations for a multi-product dividing wall column

This paper addresses possibilities and peculiarities associated with establishing the most beneficial internal configuration of a complex dividing wall column (DWC), using as a base case the separation of a multicomponent aromatics mixture into four or five product streams. As expected, the V_min-diagram method proved to be an appropriate tool in such a study, as a means for identifying and assessing promising configurations and at the same time to provide the necessary inputs and reliable initial guesses for detailed simulation-based determination of energy and stage requirements. A new, energy efficient two-top product configuration is introduced that appears to be an interesting option for a four-product DWC.     

Comparative Analysis of Energetic Properties of Ti6Al4V Titanium and EN-AW-2017A(PA6) Aluminum Alloy Surface Layers for an Adhesive Bonding Application

The purpose of this article is to present energetic properties of surface Ti6Al4V titanium as well as surface EN-AW-2017A(PA6) aluminum alloy layers. Values of surface free energy after selected mechanical operations and ozonation were compared. In addition, the influence of different values of ozone concentration on surface layer energetic activation was analyzed. Dispersive and polar components of surface free energy were of particular concern. Comparative evaluation of shearing strength of Ti6Al4V titanium and EN-AW-2017A(PA6) aluminum alloy single-lap adhesive bonded joints were presented. Results can be used as pro-ecological methods of titanium and aluminum alloys preparing for applications where adhesive phenomenon is important.     

乙烯装置裂解炉热效率影响因素分析及对策实施

乙烯装置裂解炉热效率是裂解炉的重要参数,同时与装置能耗有着十分密切的关系,提高裂解炉热效率是降低能耗的关键。本文以抚顺乙烯裂解炉装置为例,结合近几年实际运行数据对影响裂解炉热效率的主要因素进行了分析,并提出优化各项参数,在实际操作中切实可行的,提高热效率的办法。     

基于AMESIM的注塑机管道设计的节能研究

利用AMESIM软件对SZ-250A型注塑机合模系统进行了建模,通过对管道长度和直径设置不同参数进行了仿真和分析。通过对大小流量泵输出能耗的计算表明:随着管道长度的增大,注塑机能耗增大;随着管道直径的增大,注塑机能耗减小。并对注塑机在不同管道长度和直径下的压力损失和响应速度进行了分析。     

化工项目节能措施的初步设计

随着工业生产的发展,能源消耗日益增加。节能降耗,已经成为当今世界人们最关注的话题之一。如何优化节能设计,是项目建设必须认真考虑的问题。以化工建设项目为研究对象,从工艺、设备、建筑、供排水、暖通、供配电、总体布置和管理等几个方面,探讨在化工设计阶段实现节能降耗的问题。     

Thermodynamic Analysis of an Integrated SOFC,Solar ORC and Absorption Chiller for Tri‐generation Applications

Thermodynamic performance assessment of an integrated tri‐generation energy system for power, heating and cooling production is conducted through energy and exergy analyses. Sustainability assessment is performed and some parametric studies are undertaken to analyze the impact of system parameters and environmental conditions on the system performance. The tri–generation system consists of (a) an internal reforming tubular type solid oxide fuel cell (IR‐SOFC), which works at ambient pressure and fueled with syngas, (b) a combustor and a air heat exchanger, (c) a heat recovery and steam generation unit (HRSG), (d) a two‐ stage Organic Rankine cycle (ORC) driven by exhaust gases of SOFC, (e) parabolic trough solar collectors (PTSC), and (f) a lithium‐bromide absorption chiller (AC) cycle driven by exhaust gases from SOFC unit. The largest irreversibility occurs at the SOFC unit due to high temperature requirement for reactions. Fuel utilization factor, recirculation ratio, dead state conditions, and solar unit parameters have influential effects on the system efficiencies. Energy and exergy efficiencies of tri‐generation unit become 85.1% and 32.62%, respectively, for optimum SOFC stack and environmental conditions. The overall system energy and exergy efficiencies are 56.25% and 15.44% higher than that of conventional SOFC systems, respectively.     

A comprehensive model of functionals for three-dimensional non-isothermal steady flow with molecular and convective diffusion and a chemical reaction of arbitrary order

A mathematical model of diffusion-reaction, velocity and temperature functionals is developed using the calculus of variation and the concept of “local potential”. The diffusion-reaction functional, which involves both molecular and convective diffusion, describes the general case of three-dimensional steady-state diffusion of a single component with a chemical reaction of arbitrary order and complexity while the velocity and temperature functionals cover viscosity, pressure, convection and heat generation terms. The functionals have the feature of being minimum at the stationary state and can, therefore, be minimized and solved for velocity, temperature and concentration. An important feature of the present formulation for the diffusion-reaction problem is that the reaction term is linearized during the course of solution. Such linearization is inherent in the present formulation and makes the functional applicable to reactions of any type and complexity. Furthermore, the convective terms for both diffusion and heat transfer and the viscous and reaction generation terms in the energy equation are also linear and can be handled with relative ease in any numerical solution. The functionals are verified by yielding, upon minimization, the appropriate diffusion-reaction, momentum, continuity and energy equations as their Euler-Lagrange equations. Finally, the developed functionals are independent of the coordinate system and can be applied in any appropriate system of coordinates chosen for convenience.