Systems and methods for on-line pigging and spalling of coker furnace outlets
View Patent ↗Systems and methods for safe on-line pigging decoking of a coker furnace tubes and which also permits on-line spalling operations.
1. A system for on-line pigging of a tube coil for a furnace being in a delayed coking system, which comprises:
a first pressurized steam source in fluid communication with the tube coil at a tube coil first end;
a main line in fluid communication with the tube coil at a tube coil second end and in fluid communication with an additional drum input line, the main line having a first isolation valve between the tube coil second end and the additional drum input line, the main line having a second isolation valve between the first isolation valve and the additional drum input line, the first isolation valve having a high pressure end positioned toward the second isolation valve and the second isolation valve having a high pressure end positioned toward the first isolation valve;
a third valve on a second line between a fourth valve and the main line, the fourth valve in fluid communication with the main line via the second line, the second line in fluid communication with the main line at a point between the tube coil second end and the first isolation valve;
a second pressurized steam source in fluid communication with the second line at a point between the third valve and the main line;
a third pressurized steam source in fluid communication with the fourth valve, a fifth valve in fluid communication with the second line at a point between the fourth valve and the third valve and in fluid communication with a vent;
a third line in fluid communication with the main line between the first isolation valve and the second isolation valve and in fluid communication with a sixth valve;
a fourth line in fluid communication with the sixth valve and a closed blowdown system header;
a seventh valve between the closed blowdown system header and the sixth valve; and
a fifth pressurized steam source in fluid communication with a eighth valve, the eighth valve in fluid communication with the fourth line between the sixth valve and the seventh valve.
2. The system of claim 1 , further comprising a ninth valve between the second pressurized steam source and second line.
3. The system of claim 2 , further comprising a flow controller between the second pressurized steam source and the ninth valve.
4. The system of claim 3 , further comprising a pressure controller between the third line and the fourth pressurized steam source.
5. The system of claim 4 , wherein the first isolation valve is a ball valve and the high pressure end is the spring-loaded seat end of the valve and the second isolation valve is a ball valve and the high pressure end is the spring-loaded seat end of the valve.
6. The system of claim 4 , wherein the flow controller comprises a flow orifice.
7. The system of claim 4 , wherein the seventh valve is a flow regulating valve.
8. The system of claim 4 , wherein the seventh valve is a globe valve.
9. The system of claim 4 , wherein the furnace includes a plurality of coils.
10. The system of claim 4 , wherein
the pressure controller comprises a flow meter and a pressure regulator, the flow meter in fluid communication with a flow indicator, the pressure regulator in fluid communication with a pressure indicator.
11. The system of claim 4 , wherein
the flow controller further comprises a flow indicator.
12. The system of claim 4 , wherein
the first isolation valve, the second isolation valve and the main line are capable of withstanding the several thermal transients and time at elevated temperature of 1250 F or so during an on-line spalling.