Abrasive Water Jet Machining – The Review
Abrasive water jet machining (AWJM) is a relatively new machining technique. Abrasive Water Jet Machining is extensively used in many industrial applications. AWJM is a nonconventional machining process where material is removed by impact erosion of high pressure high velocity of water and entrained high velocity of grit abrasives on a work piece. There are so many process parameter affect quality of machined surface cut by AWJM. Important process parameters which mainly affect the quality of cutting are traverse speed, hydraulic pressure, stand of distance, abrasive flow rate and types of abrasive. Important quality parameters in AWJM are Material Removal Rate (MRR), Surface Roughness (SR), kerf width, tapering of kerf. This paper reviews the research work carried out so far in the area AWJM.
INVESTIGATION ON WATER JET ABRASIVE MACHINING DURING CUTTING OF CERAMIC TILE
In this paper, production of ceramic tiles by using waste raw material egg shells and sea shells additives was investigated. The egg shells and sea shells is regarded as a suitable raw material for ceramic tile production because of its physical properties and chemical composition. It’s provide high strength to the bonding of ceramic tile. Abrasive water jet cutting is a non-traditional machining method that offers a productive alternative to conventional techniques. It uses a fine jet of ultra-high pressure water and abrasive slurry to cut the target material by means of erosion. This thesis attempts to investigate kerf width and material removal rate in abrasive water jet machining of ceramic composite material tiles which is having wide applications in domestic, commercial and industrial construction work. Three different process parameters were undertaken for this study; water pressure, standoff distance and abrasive flow rate. Experiments were conducted Design of Experiment using Taguchi’s design analysis by MiniTab17. Keyword: AWJ, Taguchi, Water pressure, Standoff distance, Abrasive flow rate
Hydrogen-rich gas production from biomass air and oxygen/steam gasification in a downdraft gasifier
Biomass gasification is an important method to obtain renewable hydrogen. However, this technology still stagnates in a laboratory scale because of its high-energy consumption. In order to get maximum hydrogen yield and decrease energy consumption, this study applies a self-heated downdraft gasifier as the reactor and uses char as the catalyst to study the characteristics of hydrogen production from biomass gasification. Air and oxygen/steam are utilized as the gasifying agents. The experimental results indicate that compared to biomass air gasification, biomass oxygen/steam gasification improves hydrogen yield depending on the volume of downdraft gasifier, and also nearly doubles the heating value of fuel gas. The maximum lower heating value of fuel gas reaches 11.11MJ/Nm3 for biomass oxygen/steam gasification. Over the ranges of operating conditions examined, the maximum hydrogen yield reaches 45.16gH2/kg biomass. For biomass oxygen/steam gasification, the content of H2 and CO reaches 63.27–72.56%, while the content of H2 and CO gets to 52.19–63.31% for biomass air gasification. The ratio of H2/CO for biomass oxygen/steam gasification reaches 0.70–0.90, which is lower than that of biomass air gasification, 1.06–1.27. The experimental and comparison results prove that biomass oxygen/steam gasification in a downdraft gasifier is an effective, relatively low energy consumption technology for hydrogen-rich gas production.