Purge/sampling system for a vessel, the corresponding vessel and cleaning method using said purge/sampling system

1. A purge and/or sampling system for a vessel, comprising a purge and/or sampling line equipped with a connector adapted to be connected to the vessel, a first and a second flow regulation systems mounted in series on the purge and/or sampling line, wherein at least one injection line is connected to the purge and/or sampling line between the first and the second flow regulation systems, said injection line being connected to a source of cleaning fluid and at least one flow regulation device to control the flow of cleaning fluid through the injection line and the purge and/or sampling line, and wherein the first and second flow regulation systems each comprise at least two control valves in series.

2. Method for the hydroconversion of heavy residues, comprising hydroconverting the heavy residues in at least one hydroconversion reactor, wherein a purge and/or sampling system according to claim 1 is connected to the bottom of the hydroconversion reactor.

3. The method for the hydroconversion of heavy residues according to claim 2 , wherein the heavy residues comprise conventional vacuum distillation residue (VR) or vacuum visbroken residues (VVR).

4. The method for the hydroconversion of heavy residues according to claim 2 , wherein the purge and/or sampling system is cleaned.

5. The purge and/or sampling system according to claim 1 , wherein said injection line comprises at least one check valve to impede the cleaning fluid to flow toward the source of cleaning fluid.

6. The purge and/or sampling system according to claim 5 , wherein the at least one check valve(s) of the injection line are air operating valves.

7. The purge and/or sampling system according to claim 5 , wherein the at least two check valve(s) of the injection line are made in corrosion resistant metal.

8. The purge and/or sampling system according to claim 5 , wherein the at least one check valve includes at least two check valves, in series.

9. The purge and/or sampling system according to claim 8 , wherein the at least two check valves of the injection line are valves of different technology.

10. The purge and/or sampling system according to claim 1 , wherein the at least two control valves in series of the first and second flow regulation systems are valves of different technology.

11. The purge and/or sampling system according to claim 1 , wherein the control valves in series of the first and second flow regulation systems are two-way control valves.

12. The purge and/or sampling system according to claim 1 , wherein the control valves in series of the first and second flow regulation systems are air operating valves.

13. The purge and/or sampling system according to claim 1 , wherein the control valves in series of the first and second flow regulation systems are made in corrosion resistant metal.

14. Hydroconversion reactor of a refinery process comprising a purge and/or sampling system according to claim 1 , wherein the system is connected to the bottom of the reactor.

15. The hydroconversion reactor according to claim 14 , wherein said reactor is a hydrocarbon processing slurry reactor or a reactor intended to contain solids.

16. Method for cleaning the purge and/or sampling system according to claim 1 , the purge and/or sampling system being connected to the bottom of a vessel, wherein the method comprises providing the system of claim 1 , and then:

(i) injecting a cleaning fluid via the injection line and the purge and/or sampling line,

(ii) opening the first flow regulation system to allow said cleaning fluid to pass through said first regulation system for a sufficient period of time to clean said first flow regulation system and closing said first flow regulation system, wherein a separate or simultaneous opening of the valves in series of first flow regulation system is performed,

(iii) opening the second flow regulation system to allow said cleaning fluid to pass through said second regulation system for a sufficient period of time to clean said second flow regulation system and closing said second flow regulation system, wherein a separate or simultaneous opening of the valves in series of second flow regulation system is performed.

17. The method for cleaning the purge and/or sampling system according to claim 16 , wherein the cleaning fluid is pressurized at a pressure higher or equal to the internal pressure of the vessel before opening said first flow regulation system when internal pressure of the vessel is higher than atmospheric pressure, and the first regulation system controls the flow issued from or entering the vessel, and step (ii) is performed while the second flow regulation system is closed.

18. The method for cleaning the purge and/or sampling system according to claim 16 , wherein internal pressure of said vessel is atmospheric pressure, and steps (ii) and (iii) are performed simultaneously.

19. The method for cleaning the purge and/or sampling system according to claim 16 , wherein steps (i) to (iii) are repeated in the following sequences:

a sequence (B) wherein at least a one run of steps (i) to (iii) is performed using a liquid as cleaning fluid, and

a sequence (C) wherein at least one run of steps (i) to (iii) is performed using a gas as cleaning fluid.

20. The method for cleaning the purge and/or sampling system according to claim 16 , wherein said method is performed during or after use of the vessel in a hydroconversion process.

21. The method for cleaning the purge and/or sampling system according to claim 16 , wherein said method is performed during or after use of the vessel in a slurry hydroconversion process or in a process in which the vessel contains solids.

22. The method for cleaning the purge and/or sampling system according to claim 16 , wherein for cleaning the vessel the cleaning fluid is a gas chosen among H 2 , N 2 , Ar, He, CO 2 , CO, fuel gas, and C1 to C4 hydrocarbons alone or in combination.

23. The method for cleaning the purge and/or sampling system according to claim 16 , wherein for purging the vessel the cleaning fluid is a liquid chosen among gas oils; naphthas; C5 to C20 hydrocarbons alone or in combination; mineral oils; paraffins; vegetal or animal oils; crude oils and distillation products thereof.

24. The method for cleaning the purge and/or sampling system according to claim 23 , wherein said gas oils are selected from VGO (Vacuum Gas Oil), LCO (Light Cycle Oil), HCO (Heavy Cycle Oil), and distillate.

25. The method for cleaning the purge and/or sampling system according to claim 23 , wherein said crude oils comprise shale oils.