Refrigerant mixture for a mixture-throttling process

• US 6,513,338 B1
• Filed: 11/07/2000
• Issued: 02/04/2003
• Est. Priority Date: 05/12/1998
• Status: Expired due to Fees

• Current Assignee: Messer Griesheim GmbH
• Original Assignee: Messer Griesheim GmbH
• Inventors: Alexeev, Alexander, Quack, Hans
• Primary Examiner(s): Doerrler, William C.
• Assistant Examiner(s): SHULMAN, MARK S
• Application Number:
  US09/674,949
• Time in Patent Office: 819 Days
• Field of Search: 626/12, 626/13, 62/84, 626/23
• US Class Current: 62/84
• CPC Class Codes: C09K 2205/132 containing nitrogen
• CPC Class Codes: C09K 5/042 comprising compounds containing carbon and hydrogen only
• CPC Class Codes: F25B 43/02 for separating lubricants from the refrigerant
• CPC Class Codes: F25B 9/006 the refrigerant containing more than one component F25B9/004 takes precedence
• CPC Class Codes: F25B 9/02 using Joule-Thompson effect; using vortex effect
• CPC Class Codes: F25J 1/0052 by vaporising a liquid refrigerant stream
• CPC Class Codes: F25J 1/0092 Mixtures of hydrocarbons comprising possibly also minor amounts of nitrogen
• CPC Class Codes: F25J 1/025 Details related to the refrigerant production or treatment, e.g. make-up supply from feed gas itself

Abstract

A refrigerant mixture for a mixture throttle process contains from 0.06 mol/mol to 0.20 mol/mol propane, from 0.26 mol/mol to 0.36 mol/mol nitrogen and from 0.20 mol/mol to 0.38 mol/mol methane, the remainder being ethane.

Claims

1. A process for refrigeration in the 90 to 110 K temperature range, characterized in that a refrigerant mixture is compressed using an oil-lubricated compressor, then cooled to ambient temperature and then oil is removed from the refrigerant mixture before the refrigerant is fed to a Joule Thomson heat exchanger, and in which the refrigerant mixture is additionally cooled after it has been cooled to ambient temperature and before it enters the Joule Thomson heat exchanger, where as refrigerant mixture a mixture is used containing from 0.06 mol/mol to 0.20 mol/mol propane, from 0.26 mol/mol to 0.36 mol/mol nitrogen and from 0.20 mol/mol to 0.38 mol/mol methane, the remainder being ethane.

2. Process according to claim 1, characterized in that the refrigerant mixture contains the following proportions

nitrogen

from:

Z_N2=1.07 Z_C3H8+(0.022P_h−

0.14)mol/mol

to;

Z_N2=1.23 Z_C3H8+(0.022P_h−

0.14)mol/mol

propane

from;

Z_C3H8=0.27−

P_h/100±

0.02 (high pressure in bar)

methane

from;

Z_CH4=(2.2−

0.07P_h) Z_C3H8+(P_h−

2)/100 mol/mol

to;

Z_CH4=(2.8−

0.1P_h) Z_C3H8+(P_h−

1)/100 mol/mol

the remainder being ethane.

3. Process according to claim 2, characterized in that the refrigerant mixture has a temperature of from 233 to 243 K before entering the Joule Thomson heat exchanger.

4. Refrigerant mixture according to claim 3, characterized in that the refrigerant mixture has a pressure of from 1 to 3 bar before it is compressed, and in that the refrigerant mixture has a pressure of from 10 to 28 bar.

5. Process according to claim 1, characterized in that, in the process, the refrigerant mixture is additionally cooled after it has been cooled to ambient temperature and before the oil is removed.

6. Process according to claim 1, characterized in that, in the process, the refrigerant mixture is additionally cooled after the oil has been removed and before entering the Joule Thomson heat exchanger.

7. Process according to claim 6, characterized in that, in the process, predominantly liquid oil components are removed from the refrigerant mixture after the refrigerant mixture has been cooled to ambient temperature.

8. Process according to claim 7, characterized in that, in the process, after the predominantly liquid oil component has been removed from the refrigerant mixture, the predominantly vapor oil component is then removed from the refrigerant mixture.

9. Process according to claim 1, characterized in that, in the process, predominantly liquid oil components are removed from the refrigerant mixture after the refrigerant mixture has been cooled to ambient temperature.

10. Process according to claim 4, characterized in that the refrigerant mixture has a pressure from 1.5 to 2.5 bar before it is compressed.

11. Process according to claim 10, characterized in that the refrigerant mixture has a pressure from 1.6 to 1.8 bar before it is compressed.

12. Process according to claim 4, characterized in that the refrigerant mixture has a pressure from 12 to 18 bar after it is compressed.

13. Process according to claim 12, characterized in that the refrigerant mixture has a pressure from 14 to 16 bar after it is compressed.

14. Process according to claim 1, characterized in that the refrigerant mixture has a temperature of from 233 to 243K before entering the Joule Thomson heat exchanger.

15. Process according to claim 1, characterized in that the refrigerant mixture has a pressure of from 1 to 3 bar before it is compressed, and in that the refrigerant mixture has a pressure of from 10 to 28 bar after it is compressed.

16. Process according to claim 15, characterized in that the refrigerant mixture has a pressure from 1.5 to 2.5 bar before it is compressed.

17. Process according to claim 16, characterized in that the refrigerant mixture has a pressure from 1.6 to 1.8 bar before it is compressed.

18. Process according to claim 15, characterized in that the refrigerant mixture has a pressure from 12 to 18 bar after it is compressed.

19. Process according to claim 18, characterized in that the refrigerant mixture has a pressure from 14 to 16 bar after it is compressed.