Method and system for deriming cryogenic heat exchangers

1. A method of removing buildup in a heat exchanger, the method comprising:

a. closing a first inlet valve of pumping vessel, wherein the first inlet valve controls a supply of a solvent into the pumping vessel, wherein the pumping vessel is a positive displacement pumping vessel, wherein the solvent is liquid petroleum gas;

b. closing a first exit valve of the pumping vessel, wherein the first exit valve controls a supply of a solvent exiting the pumping vessel;

c. closing a second inlet valve of the pumping vessel, wherein the second inlet valve controls a supply of a method gas into the pumping vessel, wherein the method gas is capable of existing with the solvent without negatively impacting the integrity of the solvent, wherein the method gas is a high pressure method gas;

d. continuously opening and closing a second exit valve to maintain pressure within the pumping vessel, wherein the second exit valve controls a supply of the method gas exiting the pumping vessel;

e. opening the first inlet valve to introduce the solvent into the pumping vessel, wherein the pumping vessel includes a pumping vessel housing forming a pumping vessel chamber and a moveable float located within the pumping vessel chamber, wherein the moveable float is attached to the pumping vessel chamber by a mechanical linkage;

f. engaging the moveable float by continuously introducing solvent into the pumping vessel chamber until the solvent reaches a predetermined level, wherein upon reaching the predetermined level the mechanical linkage of the moveable float engages to close the first inlet valve, to close the second exit valve, and to open the second inlet valve;

g. opening the first exit valve of the pumping vessel to discharge the solvent, wherein the discharged solvent is injected into the heat exchanger, wherein the solvent is injected into the heat exchanger at a variable rate;

h. closing the first exit valve of the pumping vessel; and

i. closing the second inlet valve of the pumping vessel.

2. The method according to claim 1 , wherein the pumping vessel is a blowcase.

3. The method according to claim 1 , wherein the pumping vessel is a steam condensate pumping vessel.

4. The method according to claim 1 , wherein the pumping vessel is a pressure powered pumping vessel.

5. The method according to claim 1 , wherein the first inlet valve is a needle valve.

6. The method according to claim 1 , wherein the first exit valve is a needle valve.

7. The method according to claim 1 , wherein the second inlet valve is a needle valve.

8. The method according to claim 1 , wherein the second inlet valve is a needle valve.

9. A method of removing buildup in a heat exchanger, the method comprising:

a. closing a first inlet valve of pumping vessel, wherein the first inlet valve controls a supply of a solvent into the pumping vessel;

b. closing a first exit valve of the pumping vessel, wherein the first exit valve controls a supply of a solvent exiting the pumping vessel;

c. closing a second inlet valve of the pumping vessel, wherein the second inlet valve controls a supply of a method gas into the pumping vessel;

d. continuously opening and closing a second exit valve to maintain pressure within the pumping vessel, wherein the second exit valve controls a supply of the method gas exiting the pumping vessel;

e. opening the first inlet valve to introduce the solvent into the pumping vessel, wherein the pumping vessel includes a pumping vessel housing forming a pumping vessel chamber and a moveable float located within the pumping vessel chamber, wherein the moveable float is attached to the pumping vessel chamber by a mechanical linkage;

f. engaging the moveable float by introducing solvent into the pumping vessel chamber until the solvent reaches a predetermined level, wherein upon reaching the predetermined level the mechanical linkage of the moveable float engages to close the first inlet valve, to close the second exit valve, and to open the second inlet valve;

g. opening the first exit valve of the pumping vessel to discharge the solvent, wherein the discharged solvent is injected into the heat exchanger;

h. closing the first exit valve of the pumping vessel; and

i. closing the second inlet valve of the pumping vessel.

10. The method according to claim 9 , wherein the pumping vessel is a positive displacement pumping vessel.

11. The method according to claim 10 , wherein the pumping vessel is a blowcase.

12. The method according to claim 10 , wherein the pumping vessel is a steam condensate pumping vessel.

13. The method according to claim 10 , wherein the pumping vessel is a pressure powered pumping vessel.

14. The method according to claim 9 , wherein the solvent is liquid petroleum gas.

15. The method according to claim 9 , wherein the solvent is a liquefied gas including approximately 0.1 to 80 volume percent or higher methane, ethane, propane, butane, pentane, hexane or combinations thereof.

16. The method according to claim 9 , wherein the solvent is injected at a variable rate.

17. The method according to claim 16 , wherein the solvent is injected continuously into the heat exchanger.

18. The method according to claim 16 , wherein the solvent is injected intermittently into the heat exchanger.

19. The method according to claim 9 , wherein the method gas is capable of coexisting with the solvent without negatively impacting the integrity of the solvent.

20. The method according to claim 19 wherein the method gas is a high pressure method gas.

21. The method according to claim 9 , wherein the first inlet valve is a needle valve.

22. The method according to claim 9 , wherein the first exit valve is a needle valve.

23. The method according to claim 9 , wherein the second inlet valve is a needle valve.

24. The method according to claim 9 , wherein the second inlet valve is a needle valve.