Hi,
I am currently modelling a heavy oil system that uses a Return Flow atomizer. Basically a pump is used to pump oil to a gun. At the tip of the gun, the oil is swirled and either discharged through an orifice into the burner, or returned through an opening back to the pump inlet. Pump inlet pressure is controlled by a main flow valve. By varying the pump inlet pressure up and down, you also vary the pressure at the exit of the return line from the gun tip. Thus opening the main flow valve will result in increasing the pump inlet pressure which will cause the return pressure to increase in the burner tip, and less oil will return, while more will be discharged into the furnace.
The problem I have is in modeling the pressure flow relation for the return and for the discharge/spray into the furnace. Typically I would use the relation W = Cv * (DP * rho)^1/2, but this doesn't appear to be correct in this case. From a plot that I was given, it appears that the return flow is linear with return pressure, and I am not sure what relation I should use. I tried looking at some choked flow equations, but they didn't appear to fit. On top of that I am not sure if the inlet pressure to the gun is held constant, although I assume that it is kept fairly constant.
Does anyone know if the inlet pressure to the gun is held constant, and what relationship is between pressure and flow for both the discharge and the return flow
I have been banging my head on this for a week now, and would appreciate any input anyone could provide.
I am currently modelling a heavy oil system that uses a Return Flow atomizer. Basically a pump is used to pump oil to a gun. At the tip of the gun, the oil is swirled and either discharged through an orifice into the burner, or returned through an opening back to the pump inlet. Pump inlet pressure is controlled by a main flow valve. By varying the pump inlet pressure up and down, you also vary the pressure at the exit of the return line from the gun tip. Thus opening the main flow valve will result in increasing the pump inlet pressure which will cause the return pressure to increase in the burner tip, and less oil will return, while more will be discharged into the furnace.
The problem I have is in modeling the pressure flow relation for the return and for the discharge/spray into the furnace. Typically I would use the relation W = Cv * (DP * rho)^1/2, but this doesn't appear to be correct in this case. From a plot that I was given, it appears that the return flow is linear with return pressure, and I am not sure what relation I should use. I tried looking at some choked flow equations, but they didn't appear to fit. On top of that I am not sure if the inlet pressure to the gun is held constant, although I assume that it is kept fairly constant.
Does anyone know if the inlet pressure to the gun is held constant, and what relationship is between pressure and flow for both the discharge and the return flow
I have been banging my head on this for a week now, and would appreciate any input anyone could provide.