Carbon dioxide dry cleaning system

• US 6,851,148 B2
• Filed: 08/30/2002
• Issued: 02/08/2005
• Est. Priority Date: 11/26/1997
• Status: Expired due to Term

• Current Assignee: Cool Clean Technologies, LLC
• Original Assignee: Chart Incorporated (Chart Industries Incorporated)
• Inventors: Svoboda, Charles, Turner, Jon R., Preston, A. Duane
• Primary Examiner(s): Stinson, Frankie L.
• Application Number:
  US10/231,559
• Publication Number:
  US 20030005523A1
• Time in Patent Office: 893 Days
• Field of Search: 68/18.R, 68/18.C, 682/07, 68/5.C, 815/8, 815/9, 134/105, 134/108
• US Class Current: 8/158
• CPC Class Codes: D06F 43/00 Dry-cleaning apparatus or methods using volatile solvents D06F9/00 - D06F41/00 take precedence
• CPC Class Codes: D06F 43/007 Dry cleaning methods
• CPC Class Codes: D06F 43/02 having one rotary cleaning receptacle only
• CPC Class Codes: D06F 43/08 Associated apparatus for handling and recovering the solvents
• CPC Class Codes: D06F 43/081 Reclaiming or recovering the solvent from a mixture of solvent and contaminants, e.g. by distilling
• CPC Class Codes: F17C 2205/013 Two or more vessels
• CPC Class Codes: F17C 2205/0146 with details of the manifold
• CPC Class Codes: F17C 2205/0326 electrically actuated
• CPC Class Codes: F17C 2205/035 Flow reducers
• CPC Class Codes: F17C 2221/013 Carbone dioxide
• CPC Class Codes: F17C 2223/0153 Liquefied gas, e.g. LPG, GPL
• CPC Class Codes: F17C 2223/035 High pressure (>10 bar)
• CPC Class Codes: F17C 2227/0135 Pumps
• CPC Class Codes: F17C 2227/0304 using an electric heater
• CPC Class Codes: F17C 2227/0346 by forced circulation, e.g. using a fan
• CPC Class Codes: F17C 2227/0355 in a closed loop
• CPC Class Codes: F17C 2227/0393 using a vaporiser
• CPC Class Codes: F17C 2250/032 using computers
• CPC Class Codes: F17C 2250/0408 Level of content in the vessel
• CPC Class Codes: F17C 2250/043 Pressure
• CPC Class Codes: F17C 2250/0434 : Pressure difference
• CPC Class Codes: F17C 2250/0439 : Temperature
• CPC Class Codes: F17C 2250/0452 : Concentration of a product
• CPC Class Codes: F17C 2250/0491 : Parameters measured at or inside the vessel
• CPC Class Codes: F17C 2250/0631 : Temperature
• CPC Class Codes: F17C 2260/032 : Avoiding freezing or defrosting
• CPC Class Codes: F17C 2260/038 : Detecting leaked fluid
• CPC Class Codes: F17C 2260/044 : Avoiding pollution or contamination
• CPC Class Codes: F17C 2270/0545 : Tools
• CPC Class Codes: F17C 7/02 : Discharging liquefied gases

Abstract

A carbon dioxide dry cleaning system features a pair of liquid carbon dioxide storage tanks in communication with a compressor. A sealed cleaning chamber contains the objects to be cleaned. By selectively pressurizing the storage tanks with the compressor, liquid carbon dioxide is made to flow to the cleaning chamber through cleaning nozzles so as to provide agitation of the objects being dry cleaned. Liquid carbon dioxide displaced from the cleaning chamber returns to the storage tanks. In an alternative embodiment, a single storage tank is pressurized via a compressor with gas from the cleaning chamber so that liquid solvent from the storage tank travels to the cleaning chamber through nozzles. The objects in the cleaning chamber are agitated by a rotating basket. After a prewash cycle, liquid solvent from the cleaning chamber is directed to a still. The liquid solvent in the still is boiled through a connection with the head space of the cleaning chamber. The still may be positioned within the storage tank and partially surrounded with a shroud for efficient heating of the still with gas from the cleaning chamber. During agitation, liquid solvent from the cleaning chamber may be heated and filtered.

Claims

1. A method for cleaning objects in a cleaning chamber with liquid solvent supplied by a storage tank having a head space above the liquid solvent and a liquid side comprising the steps of:

a) connecting the cleaning chamber and the head space of the storage tank;

b) connecting the liquid side of the storage tank to the cleaning chamber; and

c) pressurizing the head space of the storage tank with gas from the cleaning chamber so that the liquid solvent flows from the liquid side of the storage tank to the cleaning chamber.

2. The method of claim 1 further comprising the step of agitating the objects in the cleaning chamber.

3. The method of claim 1 further comprising the step of pressurizing the cleaning chamber to an intermediate pressure above atmospheric pressure but below that of the storage tank prior to step c) to avoid thermal shock during the filling of the chamber.

4. The method of claim 1 further comprising the steps of:

d) providing a still;

e) connecting the still to the cleaning chamber;

f) draining liquid solvent from the cleaning chamber to the still so that the still contains liquid solvent with a head space there above;

g) connecting the head space of the still and the cleaning chamber; and

h) transferring gas from the head space of said still to the cleaning chamber so that the liquid solvent in the still boils and vapor produced thereby is transferred to the cleaning chamber.

5. The method of claim 4 wherein step f) includes the substeps of connecting a head space of the cleaning chamber to the still, connecting a liquid side of the cleaning chamber to the still and pressurizing the head space of the cleaning chamber with gas from the still so that liquid from the liquid side of the cleaning chamber is forced into the still.

6. The method of claim 4 further comprising the step of heating the still.

7. The method of claim 1 further comprising the steps of:

d) connecting the head space of the storage tank to the cleaning chamber; and

e) withdrawing gas from the head space of the storage tank and transferring it to the cleaning chamber so that the liquid solvent in the storage tank boils and vapor produced thereby is transferred to the cleaning chamber so that liquid solvent in the cleaning chamber is warmed.

8. The method of claim 1 further comprising the steps of:

d) providing a filter;

e) withdrawing liquid solvent from the cleaning chamber;

f) directing the withdrawn liquid solvent through the filter; and

g) returning the filtered liquid solvent to the cleaning chamber.

9. The method of claim 1 further comprising the steps of:

d) withdrawing solvent gas from a head space of the cleaning chamber;

e) warming the solvent gas; and

f) returning the warmed solvent gas to the cleaning chamber so that the liquid solvent therein is warmed.