Coke drum quench process
AssigneeChevron U.S.A. Inc.
InventorsDale William Wilborn, Eileen Imelda Love, Mark Anthony Alvarado
Life of this patent
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Abstract
Processes for quenching coke in a coke drum of a delayed coker unit that more thoroughly cool the coke, eliminate hot spots in the coke bed, and remove residual hydrocarbons from the coke prior to venting the coke drum may comprise a ramp quench phase and a pressure quench phase after the ramp quench phase. During the ramp quench phase, the coke drum internal pressure may rise to a maximum pressure level and then fall to a transitional pressure level. At least one control valve may be actuated at the transitional pressure level to increase the coke drum internal pressure from the transitional pressure level to a pulsed pressure level of the pressure quench phase.
Claims23
A process for quenching coke in a coke drum of a delayed coker unit, the process comprising:
- a) feeding quench water to the coke drum during an initial quench phase of the quenching process at an initial quench rate;
- b) after step a), increasing the rate of feeding the quench water to the coke drum during a ramp quench phase of the quenching process to attain a maximum ramp quench rate, wherein during the ramp quench phase the coke drum internal pressure increases to a maximum pressure level and thereafter the coke drum internal pressure decreases to a transitional pressure level;
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- c) at the time of the transitional pressure level, actuating at least one control valve in a blowdown system that receives overhead vapors from the coke drum, whereby the coke drum internal pressure increases from the transitional pressure level to a pulsed pressure level.
A process for quenching coke in a coke drum of a delayed coker unit, the process comprising:
- a) feeding quench water to the coke drum during an initial quench phase;
- b) increasing the rate of feeding the quench water to the coke drum during a ramp quench phase subsequent to the initial quench phase, wherein during the ramp quench phase the coke drum internal pressure increases to a maximum pressure level and thereafter the coke drum internal pressure decreases to a transitional pressure level;
- c) while the coke drum internal pressure is at the transitional pressure level, actuating at least one control valve, in a blowdown system that receives overhead vapors from the coke drum, to effect an increase in the coke drum internal pressure to a pulsed pressure level greater than the transitional pressure level;
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- d) after step c), actuating the at least one control valve to effect a decrease in the coke drum internal pressure from the pulsed pressure level to a vent pressure level.
A process for quenching coke in a coke drum of a delayed coker unit having a blowdown system, the process comprising:
- a) feeding quench water to the coke drum to effect cooling of the coke;
- b) during step a), removing a first portion of hydrocarbon vapors from the coke drum to the blowdown system until a first flow of hydrocarbon vapors from the coke drum has decreased;
- c) during step a), actuating at least one control valve in the blowdown system to effect an increase in coke drum internal pressure;
- d) releasing a second portion of hydrocarbon vapors from the coke via the increase in coke drum internal pressure;
- e) after step c), actuating the at least one control valve to effect a decrease in coke drum internal pressure;
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- f) recovering the second portion of hydrocarbon vapors from the coke drum.
Dependencies are inferred from the claim text.