53 research outputs found
Surface Morphology and In Vitro Bioactivity of Biocompatible Hydroxyapatite Coatings on Medical Grade S31254 Steel by RF Magnetron Sputtering Deposition
DESIGN AND FINITE ELEMENT ANALYSIS OF FRP LPG CYLINDER
This paper entails the design and finite element analysis (FEA) of a LPG cylinder made of E-glass fiber, vinylester resin and HDPE plastic composite The liner of the cylinder is made of HDPE plastic (blow moulding grade) and wound with continuous fiber E-glass composite with vinyl-ester polymer matrix. The cylinder cover is also made of HDPE plastic. The LPG cylinder was designed and tested for burst pressure of 3 MPa. The thickness of the cylinder was established to be 3.5 mm (1.5 mm of liner and 2 mm of FRP composite layer) using Abaqus software based FEA. Various design concepts were worked out alongwith a financial viability analysis. A strong, light, rust proof and semi-transparent LPG cylinder was aimed to be designed in this paper focusing on the use in the South African context
Reduction of sulphur in crude tyre oil by gasliquid phase oxidative adsorption
This study investigates the reduction of sulphur compounds in crude tyre pyrolysis oil through gas-phase adsorption over molecular sieve. Crude tyre pyrolysis oil was distilled at 300° C using a bench scale distillation set-up consisting of an electric heating mantle, glass round bottom flask and water cooled glass condenser. The glass condenser bulb was filled with steel wool and molecular sieve pellets for effective oxidation and adsorption of sulphur compounds in the vapours prior to condensation. It was observed that gas-phase adsorption improves total sulphur capture by 19.6%. Reduction in sharp pungent smell of the condensed distilled light fractions is justified by 21.7% total sulphur removal of low boiling point mercaptans and sulphides during moisture removal stage. High boiling point and large molecular size sulphur compounds in the distilled fractions can be further reduced by 3.6% using liquid phase adsorption over activated carbon black
Effect of in-line post diesel filtration on engine exhaust emissions and fuel consumption
The work presented in this article investigated the effect of a Whale diesel filter on engine’s exhaust emissions, fuel consumption and performance. A stationary ADE 407T heavy duty diesel engine coupled to a hydraulic dynamometer was used to investigate the performance, fuel efficiency and emissions tests under controlled conditions in a laboratory
Pyrolitic tyre derived fuel : a review
This paper reviews the potential of using waste tyre pyrolitic fuel as an alternative energy taking into account its environmental impact and national regulations. The properties of tyre derived oil and its derivatives were evaluated as a potential alternative low cost fuel for various industrial applications. The benefit of pyrolysis versus landfill disposal of waste tyres while producing low cost fuel and other value add products remains a driving force for this initiative. The downstream challenges associated with combustion of high sulphur bearing fuels such as tyre pyrolitic fuels calls for more research to into purification and refining of these fuels. Environmental Legislations on permitting the fuel production facilities, blending of the fuel derivatives with existing commercial diesel need to be clearly defined and facilitated accordingly
Investigation of single pass filtration of tyre derived fuel-diesel blend
This research reports the experimental investigation of single pass filtration of tyre derived fuel and low sulphur diesel blend using a bench scale two stage micro-molecular filtration set-up. Crude tyre pyrolitic oil obtained from slow pyrolysis of waste tyres was distillated at 250ºC to recover the light to medium fraction from the oil. The distillate was characterized and blended with low sulphur diesel at a volume ratio of 1.5:1 for bench scale filtration tests. Optimum packing densities for both micro and molecular filter media were determined followed by single pass filtration to evaluate the contaminants removal efficiencies. It was observed that the selected packing density of 168kg/m3 and pattern for micro filter medium can remove up to 2.5μm particle size in the fuel. The 18% reduction in total sulphur in the fuel after filtration was an indication of liquid phase mass transfer (molecular filtration) on the active surface of the molecular sieves
Laser beam forming of 3 mm steel plate and the evolving properties
This paper reports the evolving properties of a 3 mm low carbon steel plate after Laser Beam Forming process (LBF) To achieve this objective, the chemical analyse material and the formed components were carried out and compared; thereafter both were characterized through microhardness profiling, microstructural evaluation and tensile testing. The chemical analyses showed an increase in the elemental concentration of the formed component when compared to the as received material; this can be attributed to the enhancement property of the LBF process. The Ultimate Tensile Strength (UTS) and the Vickers microhardness of the formed component shows an increase when compared to the as received material, this was attributed to strain hardening and grain refinement brought about by the LBF process. The microstructure of the as received steel consists of equiaxed ferrit and pearlite while that of the formed component exhibits elongated grains
Microstructures, hardness and bioactivity of hydroxyapatite coatings deposited by direct laser melting process
Hydroxyapatite (HAP) coatings on bioinert metals such as Ti–6Al–4V are necessary for biomedical applications. Together, HAP and Ti–6Al–4V are biocompatible and bioactive. The challenges of depositing HAP on Ti–6Al–4V with traditional thermal spraying techniques are well founded. In this paper, HAP was coated on Ti–6Al–4V using direct laser melting (DLM) process. This process, unlike the traditional coating processes, is able to achieve coatings with good metallurgical bonding and little dilution. The microstructural and mechanical properties, chemical composition and bio-activities of the produced coatings were studied with optical microscopy, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and Vickers hardness machine, and by immersion test in Hanks' solution. The results showed that the choice of the laser power has much influence on the evolving microstructure, the mechanical properties and the retainment of HAP on the surface of the coating. Also, the choice of laser power of 750Wled to no dilution. The microhardness results inferred a strong intermetallic– ceramic interfacial bonding; which meant that the 750 W coating could survive long in service. Also, the coating was softer at the surface and stronger in the heat affected zones. Hence, this process parameter setting can be considered as an optimal setting. The soak tests revealed that the surface of the coating had unmelted crystals of HAP. The CaP ratio conducted on the soaked coating was 2.00 which corresponded to tetra calcium phosphate. This coating seems attractive for metallic implant applications
Characterizing the effect of processing parameters on the porosity of laser deposited titanium alloy powder
Laser Metal Deposition (LMD) is an additive manufacturing technique that produces parts layer by layer directly from the Computer Aided Design (CAD) file. Highly customized parts with complex shapes such as medical implants can well be manufactured using the LMD process. LMD has been used to produce a wide range of patient specific (customized) parts. Porous parts are of particular importance as medical implants because they can potentially aid the healing process and proper integration of the implant with the body tissues. In this research porous samples of titanium alloy (Ti6Al4V) were produced using the LMD process. Spherical shaped Ti6Al4V powder of particle size ranging between 150 to 200 μm was used. The effect of laser power and scanning speed on the shape, size and degree of porosity of the deposited tracks was investigated. The results showed that as the laser power was increased and the scanning speed decreased, the degree of porosity was reduced. The size of the porosity was also found to reduce as the laser power was increased
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