What is claimed is:
1. A process for cracking and further treating hydrocarbons, said process comprising:
contacting a first hydrocarbon feed stream with catalyst to yield cracked hydrocarbons and spent catalyst;
separating said spent catalyst from said cracked hydrocarbons in a separator section;
regenerating at least a portion of said spent catalyst to provide regenerated catalyst; and
contacting a second hydrocarbon feed stream with regenerated catalyst in a reaction zone under flow conditions including a superficial vapor velocity of greater than or equal to 0.6 ms (1.8 fts) and a slip ratio of greater than or equal to 2.5 to yield upgraded hydrocarbons and spent catalyst.
2. The process of claim 1 wherein the density in the reaction zone is 48 to 320 kgm3 (3.0 to 20 lbft3).
3. The process of claim 1 wherein the superficial vapor velocity in the reaction zone is 1.3 to 3.7 ms (4 to 12 fts).
4. The process of claim 1 wherein the mixture of catalyst and vapor in the reaction zone is homogeneous.
5. The process of claim 1 further comprising separating said upgraded hydrocarbons from said spent catalyst in a second separator that is distinct from the first separator; and regenerating a portion of said spent catalyst in said regenerator.
6. The process of claim 5 wherein said spent catalyst is stripped before it is regenerated.
7. The process of claim 1 wherein naphtha has the greatest concentration in said second hydrocarbon feed stream.
8. The process of claim 1 wherein said second hydrocarbon feed stream is derived from said cracked hydrocarbons.
9. A process for treating a hydrocarbon stream including at least a portion of effluent from an FCC reactor, said process comprising:
contacting said hydrocarbon stream with catalyst in a reaction zone under conditions that promote homogeneous mixing of catalyst and hydrocarbons and a slip ratio of greater than or equal to 3.0 to yield an upgraded hydrocarbon stream and spent catalyst.
10. The process of claim 9 further comprising: separating said spent catalyst from said cracked hydrocarbons in a separator section and regenerating at least a portion of said spent catalyst to provide regenerated catalyst.
11. The process of claim 9 wherein conditions in said reaction zone further include a superficial vapor velocity of greater than or equal to 0.6 ms (1.8 fts).
12. The process of claim 9 wherein the density in the reaction zone is 48 to 320 kgm3 (3.0 to 20 lbft3).
13. The process of claim 9 wherein the superficial vapor velocity in the reaction zone is 1.3 to 3.7 ms (4 to 12 fts).
14. An apparatus for the contacting of hydrocarbons with catalyst, said apparatus comprising:
a reactor vessel including at least one reactor communicating with said reactor vessel, a diluent nozzle communicating with said reactor vessel and a feed nozzle communicating with said reactor at a first end of said reactor and a second end of said reactor having a reduced cross-sectional area relative to said reactor, and
a separator vessel including a transport conduit communicating with said second end of said reactor, said transport conduit having a discharge opening communicating with said separator vessel.
15. The apparatus of claim 14 wherein said reactor vessel includes a plurality of reactors and each reactor communicates with said transport conduit through an outlet conduit.
16. The apparatus of claim 15 wherein the transport conduit has cross-sectional area that is smaller than the aggregate cross-sectional area of said plurality of reactors.
17. The apparatus of claim 14 wherein said separator vessel includes a stripping section surrounding said transport conduit.
18. The apparatus of claim 14 wherein said discharge opening is on the end of a swirl tube.
19. The apparatus of claim 14 wherein said separator vessel communicates with an external cyclone.
20. The apparatus of claim 14 wherein said apparatus is incorporated into an FCC reactor.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for digital transmission using an amplitude modulation (AM) transmitter comprising:
operating an output stage of the AM transmitter in a linear mode;
correcting a supply voltage of the output stage in the linear mode as a function of an instantaneous drive so as to improve an efficiency, the correcting being performed by:
operating a modulator of the AM transmitter as a switched-mode power supply unit so as to deliver a corrected supply voltage to the output stage; and
scanning an envelope of a complex modulated data signal so as to control the correcting, a time constant during the scanning of the envelope enabling an immediate following of a rise in the envelope; and
delaying, after the scanning, the complex modulated data signal so as to perform the correcting during the delaying so as to prevent an overdriving of the output stage.
2. The method as recited in claim 1 wherein the overdriving is a short-duration overdriving.
3. The method as recited in claim 1 wherein the time constant during the scanning is equal for a rise and a decay of the envelope.
4. The method as recited in claim 1 wherein the modulator is at least one of a pulse duration modulator and a pulse step modulator.