In blast jet type burner oil is atomized by spraying it into the path of a high pressure steam jet or air jet, steam is used generally and compressed air is used in the start up. Steam is expanded in a convergent divergent nozzle where its pressure energy is converted into kinetic energy, resulting in a high velocity jet of steam, oil is sprayed on to this path and will get atomized.the nozzles are tangential to give a rotary motion to the atomized fuel so that a rotating cone of fine fuel particles is obtained. high turn down ratio of 20:1 is available. safety valves are provided to shut of steam and fuel when it is being removed.
Since very small needle lift is obtained in the test equipment result in an unequal pressure distribution in the cut off shaft resulting in a hard contact in a small area along with high frequency oscillations, low lubricity of test oil will increase the chance of seizure. Full lift and high lubricity of heavy oil eliminates this risk of seizure during normal operation.( Always open and clean slide type valves before testing as cold sticky heavy oil along with small clearances can cause restriction in the movement of the spindle).
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