Patent Application
20150000351
1. Technical Field
The present invention relates generally to a dry cleaning machine utilizing a refrigeration system for the dry cycle of the dry cleaning machine.
2. Background
The first dry cleaning machines were no more than washer extractors that used a dry cleaning solvent in place of water and a separate steam heated and water cooled dryer. These machines did not recover the evaporated solvent during the dry cycle and just release it to the atmosphere, which had significant environmental consequences.
The next version of dry cleaning machines had a system vaporizing the solvent and passing the evaporated solvent over a cooling coil to recover the solvent so that a good portion of the evaporated solvent would be condensed back into the washer.
The next step in the evolution of cry cleaning technology was to conduct the dry cycle in the same machine that was used as the washer extractor. This system was sufficient when perchlorethylene solvents (“perc”) were used, but there was still a great loss of solvent to the atmosphere.
In order to improve the solvent recovery, a refrigeration unit was added to the machines where the refrigeration unit is used to cool down the solvent vapors and allow higher solvent recovery. This system worked fairly well until federal and local agencies determined that “perc” fumes were hazardous and began phasing out these machines.
The alternative solvents that came to the market were basically hydrocarbon solvents or their blends, which took longer to clean and were much harder to dry. The industry tried to use the same drying techniques that were in place at the time but the length of time needed for washing and drying was greater.
Another conventional dry cleaning machine uses an air cooled, heat pump drying system with a higher efficiency but has its drawbacks. The machine tends to be overheated because the air cooling cannot cooled with high ambient temperatures in the dry cleaning plants and the heat pumps tend to take a long time to build up to running temperature making the drying cycle longer.
Also, conventional dry cleaning machines are adopted to use only one kind of solvent within the machines although different kinds of solvents may be required depending on the load. For example, commonly used hydrocarbon based solvents are good for garments having leather or metal beads or losing its color easily.
However, stained garments often require a stronger solvent. In order to change the solvent, the existing solvent need to be manually purged out from the solvent tank and other parts of the machine to prevent the solvents from being mixed. During the solvent exchange process, the operator can be exposed to the harmful solvent fume. Due to inconvenience involved in the manual exchange of the solvent with a single dry cleaning system, often two separate dry cleaning machines are used for different solvents-one for stronger solvent and the other for a weaker solvent.
Accordingly, a new dry cleaning machine solving drawbacks of conventional dry cleaning machines is desirable.
According to one embodiment of the invention, a dry cleaning machine with washing and drying cycles has a rotary drum holding clothing or likes, a first solvent tank for storing a first solvent, a second solvent tank storing a second solvent, a first water separator operationally connected to the first solvent tank, a second water separator operationally connected to the second solvent tank, and a solvent recovery system operationally connected to the first and second water separators and the rotary drum.
The solvent recovery system includes a refrigeration system containing a first heat exchange system, a second heat exchange system, a refrigeration tank storing a refrigerant, and a fan for cooling the refrigerant.
The washing cycle uses one solvent from either the first or second solvent tank at a time and the drying cycle uses heated air to evaporate the solvent used in the washing cycle. The dry cleaning machine is configured on that the first and second solvents can be independently used within the same machine for different washing cycles without need of manual exchange of the solvents or system purge.
Thus, in this embodiment, the first heat exchange system heats air to be used for the drying cycle, the second heat exchange system cools and condenses the solvent evaporated by the heated air. The condensed solvent passes through the first water separator where water is separated and is then collected in the first solvent tank if the condensed solvent is the first solvent. The condensed solvent goes through the second water separator and is collected in the second solvent tank if the condensed solvent is the second solvent.
In another embodiment according to the invention, a dry cleaning machine having a washing cycle and drying cycle includes a rotary drum, a first solvent tank for storing a first solvent, a first water separator operationally connected to the first solvent tank, a second solvent tank for storing a second solvent, a second water separator operationally connected to the second solvent tank, a first solvent recovery system operationally connected to the first water separator and the rotary drum, a second solvent recovery system operationally connected to the second water separator and the rotary drum, and a refrigeration system wherein the refrigeration system comprises a first heat exchange system, a second heat exchange system, a third heat exchange system, a fourth exchange system, a refrigerant tank for storing a refrigerant, and a fan for cooling the refrigerant.
The washing cycle uses either the first solvent or the second solvent at a time and the drying cycle uses heated air to evaporate the first or second solvent used in the washing cycle.
The first heat exchange system heats air to be used for the drying cycle when the first solvent is used in the washing cycle, the second heat exchange system cools and condenses the first solvent evaporated by the air heated by the first heat exchange system, the third heat exchange system heats air to be used for the dry cycle when the second solvent is used for the washing cycle, and the fourth heat exchange system cools and condenses the second solvent evaporated by the air heated by the third heat exchange system. The first or second solvent passes through respectively the first or second water separator and is collected in respectively the first or second solvent tank.
The dry cleaning machine is capable operating with the first solvent and the second solvent independently and separately so that potential contamination of one solvent with the other is minimized.
In another embodiment according to the invention, a dry cleaning machine having a washing cycle and drying cycle includes a rotary drum, a first solvent tank for storing a first solvent, a first water separator operationally connected to the first solvent tank, a second solvent tank for storing a second solvent, a second water separator operationally connected to the second solvent tank, a third solvent tank for storing a third solvent, a third water separator operationally connected to the third solvent tank, a first solvent recovery system operationally connected to the first and second water separators and the rotary drum, a second solvent recovery system operationally connected to the third water separator and the rotary drum and a refrigeration system wherein the refrigeration system comprises a first heat exchange system, a second heat exchange system, a third heat exchange system, a fourth exchange system, a refrigerant tank for storing a refrigerant, and a fan for cooling the refrigerant. The washing cycle may use one of the first, second and third solvents at a time, and the drying cycle may use heated air to evaporate the solvent used in the washing cycle.
The first heat exchange system heats air to be used for the drying cycle when the first or second solvent is used in the washing cycle, the second heat exchange system cools and condenses the solvent evaporated by the air heated by the first heat exchange system, the third heat exchange system heats air to be used for the dry cycle when the third solvent is used in the washing cycle, and the fourth heat exchange system cools and condenses the third solvent evaporated by the air heated by the third heat exchange system.
The condensed first, second or third solvent passes through respectively the first, second or third water separator and is collected in respectively the first, second or third solvent tank, creating independent and separate solvent circulations with the machine.
In an embodiment, the dry cleaning machine can have a heat booster which can used to heat the air to be used for the drying cycle. The heat energy for the heat booster can be supplied by using steam received from an external boiler. However, other embodiment according to the present invention can have a separate internal heater to supply the heat to the heat booster. The internal heater could be an electrical heater or a small boiler.
In an embodiment, the dry cleaning machine has a refrigerant cooling system, which cools the refrigerant tank when the tank reaches at a preset temperature in order to prevent the machine from shutting down. The refrigerant cooling system can be configured to be turned off when the tank reaches at another preset temperature. The temperature of the refrigerant tank means a temperature measured at the tank or a temperature of the refrigerant exited from the tank.
The preset temperature may be about 70-100° F., preferably 80-90° F. The refrigerant cooling system may include a coolant tank storing a coolant, which is used to cool the refrigerant tank.
The coolant may be cooled by the refrigeration system when the fan provides sufficient cooling for the refrigerant.
The accompanying drawings illustrate preferred embodiments without showing many components or structures commonly used in conventional dry cleaning machines and can readily understood by one of skill in the art in absence of such components or structures.
In
When the first solvent stored in the solvent tank 601 is selected, the pump 701 transfers the solvent from the solvent tank through the filter section 201 where the solvent is filtered out impurities including color dyes.
The locations of the pumps shown in the figures are illustration purpose only, and one of skill in the art would easily optimize the locations for better or proper operations of the dry cleaning machine.
The drum 300 is operationally connected to the solvent recovery system 100 so that air heated in the solvent recovery system can circulate into the drum and the solvent evaporated from the drum by the heated air can circulate into the solvent recovery system where the solvent can be condensed and recovered.
The drum 300 optionally has a button trap 500, which trap heavy impurities such as buttons during the washing cycle.
The solvent recovery system is operationally and separately connected to two water separators, 401, 402 which are operationally connected to two solvent tanks 601, 602 respectively.
The solvent recovery system has a refrigeration system having two separate heat exchange systems—one for heating air for the drying cycle and the other for cooling and condensing the solvent evaporated during the drying cycle allowing recovery of the solvent. The refrigeration system is not illustrated in
While the two solvents stored in the solvent tanks 601 and 602 circulate within the dry cleaning machine through two separate routes, they still go through common components such as the rotary drum, the solvent recovery system, and the button trap. A small residual amount of one solvent from a dry cleaning cycle may become in contact with the other solvent from another a dry cleaning cycle.
Thus, this system is more suitable where a small amount of the solvents can be mixed without affecting operation of the dry cleaning machine or maintenance. For example, solvents with chemically the same solvent in different concentrations could be used. In a certain situation, two chemically different kinds of solvent may be also used because they may be chemically comparable or the amount of the first solvent that may contaminate the second solvent being used in a subsequent dry cleaning operation may not affect the dry cleaning operation or use of the solvent for another dry cleaning operation.
For some solvents, however, more complete segregation between their corresponding dry cleaning cycles may be desirable. A dry cleaning machine illustrated in
The dry cleaning machine in
The two solvent recovery systems may have two separate refrigeration systems but may share a single refrigeration system with extra heat exchange systems. For example, the refrigeration system can have a refrigeration tank, a fan but two separate sets of the heat exchange systems for two different solvents.
Alternatively, the refrigeration system can have only single set of the heat exchange system but the two solvent recovery systems may have two separate chambers separately positioned near the same set of the heat exchange systems so that the heating of air or condensing of the solvent caused by the same set of the heat exchange system. For example, the solvent recovery systems have coil shape chambers, which round around the same heat exchange system alternatively.
Accordingly, when an embodiment of the present invention is described in terms of multiple heat exchange systems for the same purpose, i.e., heating or cooling, such multiple heat exchange systems include physically a single heat exchange system or a less number of the heat exchange systems, providing the purported function the same multiple times as the number of the multiple heat exchange systems.
Different solvents are being used for dry cleaning machines. Hydro carbon base solvents and silicon base solvents are examples. However, many different solvents can be used. Use of different solvents do not affect the scope of the present invention.
In
The three solvent tank systems may have two separate refrigeration systems but may share a single refrigeration system with extra heat exchange systems as described with respect to
In reference to
The fan 9 alone may not be able to cool the refrigerant fast enough, causing the temperature of the refrigerant tank arises. When the temperature reaches at a critical temperature, the entire refrigeration system may shot down. In order to prevent the refrigerant tank temperature from rising over a critical temperature, a refrigerant cooler system may be provided around the refrigerant tank 1.
A refrigerant cooler system may use a coolant or the dry cleaning solvent to cool the tank. The coolant may be stored in a separate coolant tank 38, 38a. The coolant in
Water can be used as a coolant, which may be provided from an external water supply without a separate water tank.
The refrigerant cooling system may be configured to be turned on when a temperature reaches at a predetermined temperature. The predetermined temperature may be about between 70-100° F., preferably 80-90° F.
The heated air for the drying cycle can be further heated with an assistance of a heat booster 7. The heat energy required by the heat booster in heating the air may be supplied by an external source via steam as shown in
The dry cleaning machines illustrated in
The term “solvent” used herein means a single solvent or a mixture of two or more solvents. The term “different solvents” describes where the solvents are different in their concentrations, chemical compositions or both.
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
This non-provisional application claims priority under 35 U.S.C. §119(e) to U.S. provisional application No. 61/664750, entitled “A Dry Cleaning Machine” filed on Jun. 27, 2012, the contents of which are incorporated herein by reference.
