Burner Testing – Oil Burner Operation
If a pilot is provided (usually one is not), run these tests with the gas burner off. If a pilot is not provided, as is usually the case, run these tests with the gas at the minimum gas bypass pressure. The temperature of the fuel oil should be controlled to simulate the specified viscosity.
1. Move from maximum to minimum heat release maintaining the design draft and 3% oxygen in the flue gas, adjusting the steam pressure according to the atomizer design. If the gas burner is being used as a pilot, the oil rate should be such that the combined heat release does not exceed the maximum heat release. Develop the capacity curve for oil with the heat release measured by a meter on the oil flow rate. Estimate the size of the flame core and the extent of visible wisps of flame. At several points, vary the steam pressure up and down to see if atomization is improved.
2. At design draft, establish the minimum heat release below which 3% oxygen cannot be maintained in the flue gas.
3. At design draft and with the air registers set for 3% oxygen at normal heat release, increase the oil pressure until the flame becomes unstable or the stack becomes smoky. Repeat with the air registers full open and at maximum draft. Estimate the flame size at these conditions. This helps set the maximum oil pressure.
4. At design draft, establish the minimum oil pressure below which the atomizer does not work properly or below which the flame is unstable. This helps set the minimum oil pressure.
5. At design draft and maximum heat release, close and reopen the oil valve to simulate control valve closing and reopening. The burner should reignite easily.
6. At design draft and normal heat release with the air registers adjusted for 3% oxygen, open the oil valve to the maximum oil pressure and then close it to the normal pressure. The flame should not go out.
7. If the refinery steam supply system is such that pressure excursions are possible, simulate these excursions at the various conditions above. These tests help set the maximum steam pressure.
8. If the minimum oil pressure tests above were run with the gas burner acting as a pilot, they may be repeated on 100% oil.
9. Long time tests (24 hours) should be carried out to check for coke buildup on the tip or tile and to check for atomizer plugging.