Method for recycling foamed solvents

• US 4,849,027 A
• Filed: 04/16/1987
• Issued: 07/18/1989
• Est. Priority Date: 04/16/1987
• Status: Expired due to Term

• Current Assignee: Hydrochem Industrial Services, Inc. (Clean Harbors Incorporated)
• Original Assignee: Dowell Schlumberger Incorporated (Schlumberger NV)
• Inventors: Simmons, Bobby G.
• Primary Examiner(s): Sneed, H. M. S.
• Assistant Examiner(s): Cohen, Sharon T.
• Application Number:
  US07/040,544
• Time in Patent Office: 824 Days
• Field of Search: 134/4, 134/6, 134/7, 134/8, 134/10, 134/31, 134/36, 134/22.18, 134/22.19, 134/22.1, 134/21, 210/696, 210/153, 261/124, 261/DIG. 26, 261/21, 55/178
• US Class Current: 134/22.18
• CPC Class Codes: B08B 9/0804 Cleaning containers having tubular shape, e.g. casks, barrels, drums B08B9/20 take precedence
• CPC Class Codes: Y10S 261/26 Foam

Abstract

A method for using a foamed liquid for cleaning and/or inerting a vessel is described which allows for continuous recycling of the foam and its breakout liquid and gas components into regenerated foam which is continously directed back into the vessel.

Claims

1. A method for cleaning scale or foulant from a vessel with foam, comprising the steps of:

(a) providing a foam to said vessel; and

(b) providing a means for effecting continuous intimate contact between said foam and said scale or foulant, said means for effecting continuous intimate contact comprising a means for continuously removing and collecting break-out gas and dry foam from said vessel, a means for mixing said break-out gas and dry foam with a foamable liquid to continuously regenerate foam, and a means for returning said regenerated foam to said vessel.

2. A method according to claim 1, in which said means for continuously removing break-out gas and dry foam is a suction hose or pipe connected to an appropriate pump.

3. A method according to claim 1, wherein said means for mixing said break-out gas and dry foam with a foamable liquid and for continuously regenerating foam is a pump for directing said break-out gas and dry foam through a sparger submersed in said foamable liquid in said vessel.

4. A method according to claim 1, wherein said means for mixing said break-out gas and dry foam with a foamable liquid and for continuously regenerating foam comprises a compressible fluids pump.

5. A method according to claim 4, wherein said means for mixing said break-out gas and dry foam with a foamable liquid and for continuously regenerating foam further comprises a foam generator.

6. A method according to claim 1, wherein said foamable liquid is break-out liquid from the original foam.

7. A method for cleaning scale or foulant from a vessel with foam, comprising the steps of:

(a) mixing a foamable liquid and a gas to form a foamable mixture;

(b) directing said foamable mixture through a means for generating foam to form a foam;

(c) causing said foam to flow into a vessel to be cleaned;

(d) allowing said foam to react with said scale or foulant, said foam naturally breaking down into a break-out liquid and a break-out gas;

(e) continuously collecting said break-out liquid and said break-out gas as they are formed;

(f) continuously mixing said collected break-out gas and break-out liquid to form a mixture of said break-out liquid and break-out gas;

(g) directing said mixture of break-out liquid and break-out gas through a foam generator to form regenerated foam;

(h) directing said regenerated foam into said vessel.

8. A method according to claim 7, wherein said foam generator comprises a compressible fluids pump.

9. A method according to claim 7, wherein said foam generator comprises a compressible fluids pump and an additional foam generator which receives foam from said compressible fluids pump.

10. A method for cleaning scale or foulant from a vessel having an internal foam generator or sparger with foam, comprising the steps of:

(a) introducing a quantity of liquid into the vessel to be cleaned above the level of said sparger;

(b) pumping an effective amount of gas through said sparger to foam said liquid into a cleaning foam;

(c) allowing said cleaning foam to react with said scale or foulant, said foam naturally breaking down into a break-out liquid and a break-out gas;

(d) continuously collecting said break-out gas and repumping said gas through said sparger to regenerate foam.

11. A method for cleaning scale or foulant from a vessel with foam, comprising the steps of:

(a) pumping a foamable liquid into a vessel;

(b) pumping said foamable liquid from said vessel into a compressible fluids pump and thereby mixing said foamable liquid with air to form foam;

(c) pumping said foam into said vessel where said foam reacts with the scale or foulant and breaks down into break-out liquid and break-out gas;

(d) continuously collecting said break-out liquid and break-out gas from said vessel and pumping each through said compressible fluids pump to form a regenerated foam; and

(e) directing said regenerated foam into said vessel.

12. A method according to claim 11, wherein said foam generated by said compressible fluids pump is directed through a second foam generator to refine the foam before said foam is directed to said vessel.

13. A method for inerting a vessel with foam, comprising:

(a) introducing a fluid into said vessel;

(b) pumping said fluid from said vessel to a mixing area;

(c) mixing said fluid with an inert gas in said mixing area to form a foamable mixture;

(d) directing said foamable mixture through a foam generator to form inert foam;

(e) directing said inert foam into said vessel in an effective amount to displace undesirable vapors from said vessel;

(f) continuously pumping break-out liquid and break-out gas from said vessel;

(g) mixing said break-out liquid and break-out gas to form a foamable mixture;

(h) foaming said foamable mixture to form regenerated foam; and

(i) returning said regenerated foam to said vessel.

14. A method for inerting a vessel with foam, comprising:

(a) introducing an effective quantity of inert foam into a vessel to displace undesirable vapors from said vessel;

(b) continuously collecting break-out gas and break-out liquid from said vessel;

(c) mixing said break-out liquid and break-out gas to form a foamable mixture;

(d) foaming said foamable mixure to form regenerated foam; and

(e) returning said regenerated foam to said vessel.