ABRASIVE WATER-JET CUTTING by MOSES DHILIP KUMAR

ABRASIVE WATER-JET CUTTING BY MOSES DHILIP KUMAR

               Abrasive water jet cutting is an extended version of water jet cutting; in which the water jet contains abrasive particles such as silicon carbide or aluminium oxide in order to increase the material removal rate above that of water jet machining. 

                                           

Almost any type of material ranging from hard brittle materials such as ceramics, metals and glass to extremely soft materials such as foam and rubbers can be cut by abrasive water jet cutting.

WORKING PRINCIPLE :        

          

  The narrow cutting stream and computer controlled movement enables this process to produce parts accurately and efficiently. This machining process is especially ideal for cutting materials that cannot be cut by laser or thermal cut. Metallic, non-metallic and advanced composite materials of various thicknesses can be cut by this process. This process is particularly suitable for heat sensitive materials that cannot be machined by processes that produce heat while machining. 

 

The schematic of abrasive water jet cutting is similar to water jet cutting apart from some more features underneath the jewel; namely abrasive, guard and mixing tube. In this process, high velocity water exiting the jewel creates a vacuum which sucks abrasive from the abrasive line, which mixes with the water in the mixing tube to form a high velocity beam of abrasives.                    Advantages of abrasive water jet cutting ·         In most of the cases, no secondary finishing required ·         No cutter induced distortion ·         Low cutting forces on work pieces ·         Limited tooling requirements ·         Little to no cutting burr ·         Typical finish 125-250 microns ·         Smaller kerf size reduces material wastage ·         No heat affected zone ·         Localities structural changes ·         No cutter induced metal contamination ·         Eliminates thermal distortion ·         No slag or cutting dross ·         Precise, multi plane cutting of contours, shapes, and bevels of any angle.

THANK YOU DEAR READERS

ALTERNATE FUELS – BIODIESEL BY MOSES DHILIP KUMAR

                                                  
                                                                                                        BY      MOSES DHILIP KUMAR

                                                        The Recent depletion and fluctuation in prices due to uncertain supplies for fossil fuel, make us to search renewable, safe and non-polluting sources of energy.  India is not self sufficient in petroleum and has to import about two third of its requirements. Presently Indian Government spend Rupees 90,000 crores for petroleum fuel and annual consumption is around 40 millions tons.

                                                           One of the solutions to the current oil crisis and toward off any future energy and economic crunch is to explore the feasibility of substitution of diesel with an alternative fuel which can be produced in our country on a massive scale to commercial utilization.  Indian Government, research institution and  automobile industries are taking interest on bio-diesel from various non-edible oil bearing trees like Jatropha, Karanji, Mahua & Neem.  

                                                     As India is short of edible oils even for human consumption and since the cost of edible oil is also very high, it is preferable to use non-edible oils.  Jatropha curcas is one of the prospective bio-diesel yielding crops.   This paper highlights our work on alternate fuels and the importance of choosing jatropha. It reduces pollution drastically in terms of sulphates and carbon mono-oxide. To start with, we reduced the viscosity problem faced to a large extent by carrying out the transesterification process in our chemistry laboratory. we also studied the cost factor involved in the usage of jatropha. Performance test was conducted on an electrical loaded diesel engine and a study on the emissions was made using  Exhaust Gas Analyser in our thermal laboratory.

                                                                      The pollution levels came down drastically and performance was better with various blends of jatropha and diesel.

PROBLEMS OF USING JATROPHA

     The major problem in using the raw jatropha oil will be choking of the filter and other parts of the engine. Further, due to its high viscosity, raw jatropha oil can cause a lot of trouble during cold seasons. Also, the following major problems could be faced.

Due to higher density of jatropha oil, the atomization in combustion becomes difficult.

Poor volatility accounts for improper vaporization and ignition incapability. This also cause thermal cracking resulting in heavy smoke emissions and carbon deposits in the engine. Also the durability of the engine will be affected

The presence of wax contents in the oil causes formation of gum in the combustion chamber

               The above mentioned difficulties cause fluctuation of load after some period of    operation and ultimately lead to breakdown of the engine. Hence it is difficult to use Jatropha oil without further processing as fuel in a direct injection engine. It either requires the oil to be processed further or some modifications should be made in the engine. The viscosity of oil was reduced by the trans esterification process.

 

dear readers experiments under process next post i will post all chemical process  stay with  me   

thanks for visit my site