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.

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.

Abstract: The present invention provides methods and devices for freezing drops of liquid reagent solution in a cryogenic liquid. In one embodiment, the apparatus of the present invention comprises means for dispensing uniform, precisely measured drops of a liquid reagent and a rotatable carousel positioned below the dispensing means. The upper surface of the carousel has a plurality of trays each containing a cryogenic liquid, typically liquid nitrogen, for receiving the drops of liquid reagent. An alternative embodiment of the present invention comprises a tank comprising a cryogenic liquid for receiving the drops of liquid reagent. The tank has a heat source for slightly heating a portion of the cryogenic liquid such that a convection current in the cryogenic liquid is created. The convection currents in the cryogenic liquid provide mild agitation of the liquid and prevent aggregation of the frozen drops.