Abstract:
An apparatus, method, and composition provide a long-term, solid cartridge made of cleaning agents mixed at an equilibrium concentration with a solubility limiting agent for controlling an equilibrium concentration of the composition in a solvent, such as water, for example. In use, the cleaning agents are dissolved only to a predetermined concentration needed for a single dose of a cleaning appliance, such as a clothes washing machine, for example. The apparatus may be configured to cyclically expose the solid cartridge to the solvent. A dosing amount of the solvent dissolves a pre-determined concentration of cleaning agents, controlled by the solubility limiting agent. The apparatus discharges the dose of cleaning agent to a cleaning appliance, and readies itself again by dissolving a dose of cleaning agent from a surface of the solid cartridge into the solvent. An equilibrium concentration of sodium bicarbonate with amorphous silica provides the cleaning agent and solubility control, with additional sodium sesquicarbonate for alkalinity control and zeolite for scavenging hard water ions. The putty-like mixture may be cast, cured, and cooled to form a solid, monolithic charge in a desirable shape for controlling surface area.

Description:
This is a division of application Ser. No. 09/437,532 filed Nov. 10, 1999 now U.S. Pat. No. 6,403,501. 
    
    
     BACKGROUND OF THE INVENTION 
     1. The Field of the Invention 
     The present invention relates to cleaning systems, and, more specifically, methods, apparatus, and compositions for cleaning with water, including compositions and dispensers for controlling concentrations of cleaning agents delivered into water. 
     2. The Relevant Technology 
     Chemical cleaning agents, in one form or another, have long been used to remove dirt, oil, and particulate matter from a wide variety of articles. Cleaning improves the visual and tactile impression of an article, kills potentially harmful microbes, removes particles that interfere with breathing and vision, and may even extend the life of the article being cleaned. Things such as cookware, homes, automobiles, clothing, and the human body itself stand to benefit from the development of enhanced cleaning agents. Although the present invention contemplates cleaning systems useful for cleaning a wide variety of articles, it is particularly well-adapted for cleaning clothes, as in a washing machine. 
     Soaps and detergents are two of the most common cleaning agents presently used. While they are often used interchangeably, the words “soap” and “detergent” actually denote different classes of compounds. 
     Soaps are made by a process of saponification wherein a fatty acid reacts with abase to yield the salt of the fatty acid, i.e., a soap. Soap probably has its origin in reacting animal fats, or lard, with alkaline salts, such as wood ash. Today, they are largely synthesized from animal fats and plant oils. Molecules of soap owe their cleaning capacity to their amphiphilic structure, which includes a hydrophobic portion consisting of a long hydrocarbon chain, and a hydrophilic portion composed of an ionic group at one end of the hydrocarbon chain. Because of the hydrocarbon chain, a molecule of soap is not truly soluble in water. Numerous molecules of soap will suspend in water as micelles, or clusters of molecules with long hydrocarbon chains in the inner portions of the cluster, and ionic, water soluble ends facing the polar water. 
     Because these micelles form hydrophobic centers, they are able to dissolve other non-polar substances, like oils. Once the non-polar, oily dirt is dissolved within the micelles of soap, the ionic surfaces of the micelle repel each other, suspending the oil droplets and preventing them from coalescing. In this fashion, dirt and oil become trapped within the water soluble micelles, and wash away with the water. 
     A primary disadvantage of soaps is that they form insoluble salts (precipitates) with ions found in hard water. These salts, usually formed when Ca++ and Mg++ ions react with the carboxylate ends of soap molecules, precipitate out of solution as bathtub rings, grits, and other deposits. Water softeners that exchange Ca++ and Mg++ ions for more soluble Na+ ions can alleviate most of this problem. 
     Most laundry products and many household cleansers actually contain detergents, not soaps. A detergent is a compound with a hydrophobic hydrocarbon chain plus a sulfonate or sulfate ionic end (whereas soaps have carboxylic ends). Because detergents also have an amphiphilic structure, they also form micelles and clean in the same fashion as soaps. However, detergents have the advantage that most metal alkylsulfonates and sulfates are water-soluble. Therefore, detergents do not precipitate out of solution with metal ions found in water. As a result, detergents are not inhibited by hard water. In addition, detergents can be synthesized with continuous chain alkyl groups, which are more easily broken down, or biodegraded, into smaller organic molecules by the microorganisms in septic tanks and sewage treatment plants. 
     A drawback of most detergents is that they contain additives that take much longer to biodegrade. Some components containing phosphates must be treated in plants. Phosphates therefore promote algae growth, chocking bodies of water and streams. Another disadvantage of detergents is that they can leave behind an undersireable residue even after thorough rinsing. 
     Detergents are currently used in many household appliances, such as dishwashers and washing machines. Presently, a user must measure out a dose of detergent to add to the cleaning appliance before every cleaning cycle. Conventional packaging and use of detergents creates messy clutter, consumes time, and typically results in a waste of detergent from overdosing. In addition, most washing machines for clothing use a separate rinsing cycle in order to remove the residue. Thus, additional time, water, and heat energy are required to complete the washing process. 
     It would be a great advancement in the art to provide a novel cleaning system that uses a novel non-detergent composition of cleaner that leaves no residue and therefore, requires no rinsing cycle. Another improvement in the art would be to provide a cleaning agent that is completely biodegradable. Still another improvement would be if this cleaning agent were made from all natural materials. It would also be a great advancement in the art to provide a new method for making a non-detergent cleaning agent. It would be another advancement in the art to provide a cleaning agent that cleans better than the detergents presently on the market. Furthermore, it would be an improvement in the art to simplify the cleaning process and ameliorate the resultant mess with improved, preferably measurement-free or automatic, dosing over many cleaning cycles. 
     OBJECTS AND BRIEF SUMMARY OF THE INVENTION 
     In accordance with the invention as embodied and broadly described herein, an apparatus, composition, and method are disclosed, in suitable detail to enable one of ordinary skill in the art to make and use the invention. In certain embodiments, an apparatus for dispensing cleaning agents in accordance with the present invention includes a vessel comprising a cavity with a cartridge support for mounting a replaceable cartridge. 
     In one embodiment, the cartridge comprises a novel composition of cleaning agent for cleaning, and solubility control component for controlling the equilibrium concentration of the cleaning composition in solution, further described below. A water source supplies water into the cavity, and a water feed conveys water from the cavity to a cleaning appliance such as a brush, wand, dishwasher, or washing machine for clothing. The apparatus provides a cleaning agent solution in water to the cleaning appliance. 
     In one embodiment, the inner cavity (and hence the cartridge) of the canister is flooded with water from a water source. The cartridge then dissolves to an equilibrium concentration within the vessel, thus forming a cleaning solution comprising a cleaning agent and a solubility control component to control the concentration of the cleaning agent. The vessel is then purged of the solution, which enters the water feed to be carried into a cleaning appliance. 
     Enough cleaning solution should be delivered to the feed, to bring the cleaning composition to cleaning concentration when diluted in the washing appliance. Cleaning concentration is the amount of cleaning composition necessary to clean those items serviced by (e.g. placed within) the cleaning appliance during a wash cycle. In particular, a cleaning concentration for a washing machine is that concentration needed to clean a load of clothing. The amount of cleaning composition delivered to the feed is controlled by the amount of cleaning solution and the cleaning solution&#39;s equilibrium concentration. Therefore, the vessel should be configured to receive a predetermined amount of solution, and the solubility control in the cartridge should be configured to dissolve a predetermined equilibrium concentration of cleaning composition in the vessel. 
     As explained, a composition of cleaner in accordance with the present invention may include a mixture of a cleaning agent and a solubility control agent in a solid state. In some embodiments, the mixture may also comprise an additional alkalinity agent and a water softener. The principal cleaning agent is preferably a gas-releasing compound, e.g. sodium bicarbonate. Gas-releasing compounds clean by reacting with acids (soils) and by mechanical microscrubbing as they yield carbon dioxide. The solubility control agent is preferably a material resistant to dissolving in water, e.g., amorphous silica. These compounds control solubility by dissolving only an equilibrium concentration of composition in solution. 
     The alkalinity agent is preferably a basic compound found in nature, e.g., sodium sesquicarbonate (which actually contains sodium bicarbonate and sodium carbonate in a substantially 1:1 ratio). The alkalinity agent prevents the cleaning agent from releasing carbon dioxide too quickly by increasing the pH of the solution. The water softener is preferably a naturally occurring material capable of solvating hard water ions, e.g., natural zeolite. The water softener prevents hard ions from reacting with other components to form insoluble salts. 
     The composition of cleaner may be formulated and cured into various shapes; however, a cylindrical cartridge with an annular cross section is presently preferred. The annular shaped cylinder has an advantage over other shapes in that, as it dissolves, it retains approximately the same surface area, and hence the same dissolution rate. This is because the annular shape yields an interior surface that increases in area at approximately the same rate as that of the exterior surface decreases. 
     The amount of solubility control component in the composition determines the equilibrium concentration of the composition in a solution, e.g., water. Therefore, the amount of solubility control component should be sufficient to yield a predetermined equilibrium concentration of composition. Similarly, the amount of cleaning agent should be sufficient to provide a predetermined amount of gas in solution. The amount of alkalinity agent should be sufficient to provide a predetermined pH in solution. The amount of water softener should be sufficient to soften household water in solution. 
     In certain embodiments, a method for making a composition of cleaner in a solid state may include providing a solvent, providing a gas-releasing agent, and providing a solubility control component. The method may also include providing an alkalinity agent. The fabrication process may typically include applying energy, mixing, and testing the composition for an equilibrium concentration. Completion of the process may include casting the composition in a shape selected to control surface area, cooling the composition, and curing the composition. 
     In other embodiments, a method for using an apparatus for delivering solvated cleaning agents to a cleaning appliance may include providing a dispensing apparatus, shutting off a water supply, opening the dispensing apparatus, installing a shaped block of a cleaning agent, and closing dispensing apparatus. Thereafter, the method may include turning water supply on, running wash cycles, and selectively dissolving a portion of the cleaning agent at a controlled rate with each fill cycle. 
     In certain embodiments of the present invention, a method for delivering cleaning solution to a cleaning appliance may include flooding a dispensing apparatus with a solvent, dissolving a portion of a hardened charge of cleaning agent, equilibrating a solution of cleaning agent, and flushing the dispensing apparatus. The method may include delivering a cleaning agent solution to a cleaning appliance, cleaning through basic reactions and gas release, and draining waste from the cleaning appliance. 
     These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the manner in which the above-recited and other advantages and objects of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of apparatus and methods possible in accordance with the invention, which are, therefore, not to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
     FIG. 1 is a perspective view of a cleaning appliance provided with an apparatus in accordance with the invention; 
     FIG. 2 is a perspective view of a cleaning appliance having a built-in vessel and control in accordance with the invention; 
     FIG. 3 is a perspective view of an apparatus in accordance with the invention; 
     FIG. 4 is a partially-cutaway perspective view of one embodiment of the apparatus of FIG. 3; 
     FIG. 5 is a side elevation section view of one embodiment of the apparatus of FIG. 3; 
     FIG. 6 is a perspective view of the fill and purge system suitable for the apparatus of FIG. 3; 
     FIG. 7 is a cutaway perspective view of an alternative embodiment of the apparatus of the invention; 
     FIG. 8 is a schematic diagram of a method for connecting a cleaning apparatus to an apparatus suitable for the invention; 
     FIG. 9 is a schematic diagram of a method for using a cleaning system in accordance with the invention; 
     FIG. 10 is a schematic diagram of a method for carrying out a wash cycle according to the invention; 
     FIG. 11 is a perspective view of a replaceable cartridge in accordance with the invention; 
     FIG. 12 is a schematic diagram of components that may form a composition suitable for the present invention; 
     FIG. 13 is a schematic diagram of one embodiment of a composition according to the invention, including the components shown in FIG. 12; 
     FIG. 14 is a schematic diagram of steps that may form a cleaning process according to the invention; 
     FIG. 15 is a schematic diagram of one embodiment of a cleaning process according to the invention, including the steps shown in FIG. 14; 
     FIG. 16 is a schematic diagram of steps that may be used to make a cartridge according to the invention; 
     FIG. 17 is a schematic diagram of one embodiment of a process of making a cartridge according to the invention, including the steps shown in FIG. 16; and 
     FIG. 18 is a pictorial process diagram of steps that may be used to make a cartridge according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The presently preferred embodiments of the present invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus, system, and method of the present invention, as represented in FIGS. 1 through 18, is not intended to limit the scope of the invention, as claimed, but is merely representative of presently preferred embodiments of the invention. 
     Those of ordinary skill in the art will, of course, appreciate that various modifications to the details of the figures may easily be made without departing from the essential characteristics of the invention. Thus, the following description of the figures is intended only as an example, and simply illustrates one presently preferred embodiment that is consistent with the invention as claimed. 
     Referring to FIG. 1, the present invention relates to an apparatus  10  for delivering cleaning compositions  11  in solvated form, that may be disposed between a water supply  12  and water feed  14 . In one preferred embodiment, the water feed  14  leads to a cleaning appliance  16  (e.g., a washing machine). The apparatus  10  may deliver a cleaning solution  17  of cleaning agent to a cleaning chamber  18  of the cleaning appliance  16 . 
     The apparatus  10  may be mounted to any suitable surface, such as a wall  19  near the cleaning appliance  16 , by a mount  20 , as shown in FIG.  1 . Those skilled in the art will appreciate that the mount  20  may take various forms, including a bracket system, a mount arm, a shelf, and various other forms capable of fixing the apparatus  10  to a surface. The water supply  12  preferably provides comparatively unheated water. A separate line  21  may convey heated water to the cleaning appliance  16 . 
     The water supply  12  and water feed  14  may also have valves  22 ( a ) and  22 ( b ) connected to allow a user to turn a water flow on and off. The valves  22 ( a ) and  22 ( b ) may take various forms known in the art, including ball valves, sliding spool valves, solenoid valves, and any other type of valve with a manual or electronic control whereby a user may control a flow of water flowing through the apparatus  10 . In particular, the valve  22 ( a ) may be situated on the water supply  12  to control flows into the apparatus  10 , and the valve  22 ( b ) may be positioned on the water feed  14  to control flows from the apparatus  10  to the cleaning appliance  16 . 
     In an alternative embodiment of the invention, best illustrated in FIG. 2, the apparatus  10  may be contained within the cleaning appliance  16 . A water mixer  24  combines flows from a line  21  conveying heated water and a line  25  supplying cold water. The apparatus  10  is preferably positioned downstream from the water mixer  24 , as depicted in FIG. 2, but may also be positioned on the line  21  or the line  25 . As with the previously described embodiment, the water feed  14  conveys solvated water from the apparatus  10  to the cleaning chamber  18 . The cleaning appliance  16  may have a hatch  26  to allow access to the apparatus  10 . Numerous other plumbing configurations, including a bypass system, could also be used according to methods known in the art. 
     Referring to FIGS. 3 and 4, one possible embodiment of the apparatus  10  of the present invention has a vessel  27  for containing water in an interior cavity  28  thereof. The vessel  27  may take any shape that maintains an interior cavity  28  to accommodate a cartridge  30  of solidified cleaning composition  11 . However, a cylindrical shape with an annular cross section is presently preferred. The vessel  27  may be constructed out of any air and water tight material, including metals, plastics, ceramics, composites, etc. The apparatus  10  further has an inlet port  32  formed in the vessel  27  to permit the ingress of water from a water supply  12  to the interior cavity  28 , and an outlet port  34  formed in the vessel  27  for flushing water from the interior cavity  28  into a water feed  14 . Thus, water flows into and out of the vessel  27  in the direction of the arrows shown in FIG.  4 . 
     In one embodiment of the present invention, best illustrated in FIG. 4, the vessel  27  includes a support  36 . The support  36  may be any structure that supports a cartridge  30  of solidified cleaning composition  11 , including an interior wall  38  of the vessel  27  itself. However, in the presently preferred embodiment, the support  36  is a separate structure attached to the interior wall  38  of the vessel  27  such that it spans a cross section of the vessel  27 . The cartridge  30  may then rest on the support  36  when the vessel  27  is in the upright position, as illustrated in FIG.  3 . The support  36  may be configured to accommodate cartridges of different sizes and shapes. 
     Preferably, the support  36  is water permeable, and may be composed of a simple mesh to allow water to flow freely between the inlet and outlet ports  32  and  34  and the cartridge  30  while maintaining a separation therebetween. When the cartridge  30  is immersed in water, a cleaning solution  17  is formed and retained within the interior cavity  28 . 
     Flows through the inlet port  32  and outlet port  34  may converge in a mixing tube  40 . The mixing tube  40  may run through the interior cavity  28  and may also be U-shaped to connect the water supply  12  with the water feed  14  through the inlet and outlet ports  32  and  34 , respectively. Water may be conveyed through the inlet port  32  via an inlet fitting  42 , disposed on the outside of the vessel  27  with a fastener  43  to connect the water supply  12 . Although the fastener  43  may take any form selected to couple the inlet fitting  42  to the water supply  12 , threads  43  on the inlet fitting  42 , for engagement with similar threads on the water supply  12 , are preferable. The outlet port  34  may have an outlet fitting  44 , disposed on the outside of the vessel  27 , with a fastener  46  that may also take the form of threads  46 . It will be readily appreciated by those skilled in the art that the inlet fitting  42  and outlet fitting  44  may take any form adapted to connect a water supply  12  and a water feed  14 , respectively, and such forms are within the scope of the present invention. 
     Referring now to FIGS. 5 and 6, and according to one embodiment of the present invention, the vessel  27  may have a bottom cap  48  with a base  50  and an annular wall  52 . The base  50  may be circular in shape and may be unitary with the annular wall  52 , which may extend perpendicular to the base  50  to fit into the interior cavity  28  of the vessel  27 . The annular wall  52  preferably includes threads  54 ( a ) to engage similar threads  54 ( b ) on the interior wall  38  of the vessel  27 . A user may affix the bottom cap  48  to the vessel  27  by twisting or screwing the threads  54 ( a ) and  54 ( b ) into an interlocking position, best illustrated in FIG.  5 . Other methods for affixing the bottom cap  48  to the vessel  27 , including latches, friction fittings, separate fasteners, and others, are known in the art. 
     The bottom cap  48  may form a water-tight seal with the vessel  27  when the wall  52  engages an o-ring  56 , held in place by a lip  58  disposed on the interior wall  38  of the vessel  27 . As shown in FIG. 6, the mixing tube  40  may extend through the base  50  of the bottom cap  48  and into the interior cavity  28 , to permit easy connection and disconnection of the water supply  12  and the water feed  14 . 
     In one preferred embodiment, the inlet port  32  has an intake system  74  connected to the mixing tube  40  for delivering water from the mixing tube  40  into the interior cavity  28 . This intake system  74  may take various forms, but a simple bent tube, hereinafter a separation tube  74 , as illustrated in FIG. 6, is presently preferred. As water runs through the mixing tube  40  from the water supply  12  to the feed  14 , the separation tube  74  diverts some water into the interior cavity  28 . If the mixing tube  40  and the separation tube  74  are unobstructed, the vessel  27  may fill completely with water. Alternatively, as illustrated in FIG. 6, a valve  76 , such as a check valve in the separation tube  74 , may limit flow into the interior cavity  28 . The valve  76  may also be positioned within the mixing tube  40 . In one embodiment, a valve  76  may be configured to allow only a predetermined amount of water to enter the interior cavity  28 , by means such as a flow control valve, or a metering valve, for example. 
     As shown in FIG. 6, the mixing tube  40  also has a delivery system  78  connected to the mixing tube  40  for delivering water from the interior cavity  28  back into the mixing tube  40 . The delivery system  78  may take various forms, but a siphon tube  78  is presently preferred. As water flows through the mixing tube  40  from the water supply  12  to the feed  14 , it encounters the siphon tube  78 , which decreases the cross-sectional area of the mixing tube  40 . The result is a venturi effect. An area of comparatively low pressure water forms about the siphon tube  78  to draw water out of the interior cavity  28  and into the mixing tube  40 . In this embodiment, the outlet port  34  is passive. 
     If the mixing tube  40  and the siphon tube  78  are unobstructed, the vessel  27  is continuously flushed as water circulates through the mixing tube  40 . However, in the embodiment illustrated in FIG. 6, a valve  80 , such as a check valve in the siphon tube  78 , may limit flow out of the interior cavity  28 . The valve  80  may also be positioned within the mixing tube  40 . The valve  80  may be configured to allow only a predetermined amount of water to leave the interior cavity  28 , such as a flow control valve, or a metering valve by way of example. 
     As shown in FIG. 5, the vessel  27  may also have a top cap  60 , which may be removable to allow access to the interior cavity  28 . The top cap  60  has a base  62  that is substantially circular with an annular wall  64  running perpendicular to the base  62  near its outer circumference. The inner portion of the wall  64  has threads  66 ( a ) that engage similar threads  66 ( b ) on the outer wall of the vessel  27 . A user may affix the top cap  60  to the vessel  27  by twisting or screwing the threads  66 ( a ) and  66 ( b ) together into an interlocking position. As with the bottom cap  48 , numerous methods for affixing the top cap  60  to the vessel  27  are within the scope of the present invention, including latches, friction fittings, separate fasteners, etc. The top cap  60  forms a water tight seal with the vessel  27  when the wall of the vessel  27  engages an o-ring  68 , held in place by a lip  70  disposed along the inner circumference of the base  62 . 
     Referring to FIG. 7, in an alternative embodiment, the inlet port  32  and the outlet port  34  of the vessel  27  may be configured with a flow-through design. In this embodiment, the inlet and outlet ports  32  and  34  are disposed on opposite ends of the vessel  27 , with the interior cavity  28  between the inlet and outlet ports  32  and  34 . The cartridge  30  may be held within the vessel  27  by separators  71 ( a ) and  71 ( b ) that are water permeable and preferably constructed of a mesh material. The separator  71 ( a ) separates the cartridge  30  from the inlet port  32 . The separator  71 ( b ), in turn, separates the cartridge  30  from the outlet port  34 . 
     Referring to FIG. 8, one method of connecting the apparatus  10  to the cleaning appliance  16  is shown. This method applies to several different cleaning processes. Although the apparatus  10  may be configured in several different ways for use with this method, the following descriptions for FIGS. 8,  9 , and  10  relate directly to the exemplary embodiments described in connection with FIGS.  1  and  3 - 6 . 
     In a typical cleaning appliance  16  of the type used to wash clothing, the water supply  12  and the heated water line  21  connect directly to the cleaning appliance  16 . Thus, in a first step  84 , a user may be required to restrict the flow of water through the water supply  12  by closing the valve  22 ( a ) before disconnecting the water supply  12  from the cleaning appliance  16 . Then, in a second step  86 , a user may disconnect the water supply  12  from the cleaning appliance  16 . A user then connects the water supply  12  to the apparatus  10  via the inlet fitting  42  in a third step  88 . Then, in a fourth step  90 , a user connects the water feed  14  to the vessel  27  via the outlet fitting  44  and to the cleaning appliance  16 . In a fifth step  92 , a user may open the valve  22 ( a ) to turn the water back on. 
     Referring to FIG. 9, a method for using the apparatus  10 , after connection to a cleaning appliance  16  through the steps described above, is disclosed. In a first step  94 , a user shuts off the water supply by closing the valve  22 ( a ). A user then opens the vessel  27 , by removing the top cap  60 , in a second step  96 . In a third step  98 , the cartridge  30  is placed in the interior cavity  28  of the vessel  27 . In a fourth step  100 , a user closes the vessel  27  by replacing the top cap  60 . A user may then turn the water supply on again, in a fifth step  102 , by turning on valve  22 ( a ). After the cartridge  30  has become depleted through use, a user may repeat steps  94 - 102  to install a new cartridge  30  for further washing. 
     FIG. 10 shows a possible washing cycle that incorporates the apparatus  10 . After the water supply  12  has been turned on in the step designated  102  above, a first step  112  occurs, wherein the interior cavity  28 , and hence the cartridge  30 , of the vessel  27  is flooded with water from the water supply  12 . Water from the water supply  12  enters the mixing tube  40  and is diverted through the separation tube  74  to reach the interior cavity  28 . The valve  76  restricts flow through the separation tube  74  after a predetermined amount of water is delivered into the interior cavity  28 . Since the portion of the cartridge  30  that dissolves is directly related to the amount of water in the cavity  28 , limiting the inflow of water ensures that approximately the same amount of cleaning composition  11  is dissolved every time the vessel  27  is flooded. In one embodiment, the valve  76  is configured to allow about 0.68 quarts into the interior cavity  28 . 
     Once the interior cavity  28  has flooded with water, a portion of the cartridge  30  (comprised of a cleaning composition  11 ) dissolves in the water in a second step  114 . The cartridge  30  stops dissolving when the concentration of cleaner in the water reaches a predetermined equilibrium. As a result, a cleaning solution  17  is formed by a cleaning composition  11  dissolved in water. In one embodiment, the predetermined equilibrium concentration of the cartridge  30  is from 0.001% to 1% cleaning composition  11 , by weight in water. Even more preferred is an equilibrium concentration from 0.01% to 0.2% cleaning composition  11  by weight. An equilibrium concentration of about 0.12% cleaning composition  11  is most preferred. 
     The time it takes for the cartridge  30  to reach equilibrium concentration depends on the type of cleaning composition  11 , and the configuration of the cartridge  30 . Cartridges with more surface area will reach equilibrium more quickly than those with less surface area. In one presently preferred embodiment, the cartridge is cylindrical with an annular cross section. The annular shape is beneficial because, as the cartridge dissolves, it retains approximately the same overall surface area. The inner surface area increases at approximately the same rate as the exterior surface area decreases. In one presently preferred embodiment, the cartridge is configured to reach equilibrium concentration in approximately 17 minutes. 
     Once the cartridge  30  reaches equilibrium concentration, the cleaning solution  17  leaves the interior cavity  28  and enters the water feed  14  via the siphon tube  78  in a third step  118 . The valve  80  allows only a predetermined amount of cleaning solution  17  to be delivered into the water feed  14 . In a fourth step  120 , the water feed  14  leads to a cleaning chamber  18  of a cleaning appliance  16 , wherein the cleaning solution  17  is diluted by excess water to a concentration suitable for cleaning. 
     The concentration of cleaning composition  11  used for cleaning may be any concentration that cleans the items within the cleaning chamber  18 . In particular, cleaning concentration for a cleaning appliance  16  for washing clothing is that concentration needed to clean a load of clothing. However, a cleaning solution  17  that is diluted to a cleaning concentration from 0.0001% to 0.01% cleaning composition  11  by weight is presently preferred. Even more preferred is a cleaning concentration from 0.0014% to 0.002% cleaning composition  11  by weight. A cleaning concentration of about 0.0017% cleaning composition  11  by weight is most preferred. 
     Enough cleaning solution  17  should be delivered to the water feed  14 , such that the cleaning composition  11  is at cleaning concentration when diluted into the cleaning appliance  16 . The amount of cleaning composition  11  delivered to the water feed  14  is determined by the amount of cleaning solution  17  and the equilibrium concentration of the cleaning solution  17 . Therefore, the vessel  27  should be configured to receive a predetermined amount of solvent (e.g., water), and the cleaning composition  11  in the cartridge  30  should be configured to dissolve a predetermined equilibrium concentration of cleaning composition  11  in the vessel  27 . 
     Once the cleaning solution  17  has been delivered to the cleaning appliance  16 , a fifth step  122  occurs, wherein items to be cleaned are exposed to the cleaning solution  17 . This sixth step  122  may involve a number of different process steps, depending on the type of item to be cleaned. For example, items may be immersed in the cleaning solution  17 , lightly sprinkled with the cleaning solution  17 , exposed to cleaning solution  17  in gaseous form, stirred or tumbled through the cleaning solution  17 , exposed to other, additional agents, or any combination of these or other cleaning processes known in the art. In a sixth step  124 , the cleaning appliance  16  drains the cleaning solution  17 , together with removed impurities, from the cleaned items. 
     Referring to FIG. 11, the cartridge  30  is shown in greater detail. The cleaning composition  11  relates generally to any composition of cleaner. As shown in FIG. 11, the cleaning composition  11  may include a mixture of different agents evenly dispersed throughout the cartridge  30  in a solid or semi-solid form. The cartridge  30  need not be unitary, but may be made up of cleaning composition  11  in powder or granular form. However, the cartridge  30  is preferably unitary and configured to remain firmly in place within the vessel  27 . In one presently preferred embodiment, the cartridge  30  is cylindrical with an annular cross section, so that the time required for the cleaning composition  11  to dissolve remains relatively constant over multiple cycles of use. 
     Referring to FIG. 12, the cleaning composition  11  may include a gas-releasing agent  128  that is water soluble, and a solubility control agent  130  that is only slightly water soluble. The gas-releasing agent  128  provides cleaning action. However, if the gas-releasing agent  128  is permitted to freely dissolve, the resulting cleaning solution  17  will have an unknown or uncontrolled concentration of gas-releasing agent  128 . Thus, it is desirable to add a solubility control agent  130  to the cleaning composition  11  to control its equilibrium concentration, and hence, the concentration of gas-releasing agent  128  in the cleaning solution  17 . 
     The cleaning composition  11  may be further enhanced through the addition of an alkalinity agent  132  and a softener  134 . The alkalinity agent  132  controls the pH of the cleaning composition  11 , and therefore the pH of the resultant cleaning solution  17 . The pH of the cleaning solution  17  must remain within a certain range because the pH controls the rate at which the gas-releasing agent  128  reacts. The gas-releasing agent  128  or the solubility control agent  130  may be configured to control the pH of the cleaning solution  17 , but a separate alkalinity agent  132  is presently preferred. The softener  134  prevents the formation of a residue on the items to be cleaned by solvating hard water ions. The gas-releasing agent  128 , the solubility control agent  130 , or the alkalinity agent  132  may be configured to solvate hard water ions, but a separate softener  134  is preferable. 
     Referring now to FIG. 13, an exemplary embodiment of the cleaning composition  11  is shown. The gas-releasing agent  128  should not release gas in the solid state cleaning composition  11 , but it should be able to release gas in a cleaning solution  17  of the cleaning composition  11  at ambient temperature. The gas-releasing agent  128  need not react with other agents, but may simply decompose at ambient temperature to release gas. Those gas-releasing compounds that are both found in nature and biodegradable are preferred. In some embodiments, the gas-releasing agent  128  is a carbonate or bicarbonate. Sodium bicarbonate  136  (NaHCO 3 ), for example, is occurs in nature and is completely biodegradable. Alternatively, sodium carbonate (Na 2 CO 3 ) may act as the gas-releasing agent  128 . However, numerous other gas-releasing agents are known to those skilled in the art, and all are within the scope of the present invention. 
     The solubility control agent  130  should be either water insoluble or only slightly water soluble. Numerous compounds may serve this function, including but not limited to hydrophobic compounds. Those solubility control agents that are both found in nature and biodegradable are preferred. Amorphous silica  138  (H 2 SiO 3 ) is presently preferred because it occurs in nature and is completely biodegradable. 
     The alkalinity agent  132  may be selected from, but is not limited to, a group consisting of alkali hydroxide, alkali hydride, alkali oxide, alkali carbonate, alkali bicarbonate, alkali phosphate, alkali borate, alkali salt of mineral acid, alkali amine, alkaloid, alkali cyanide, alkali metal, and alkali earth metal. Other alkalinity agents that tend to increase the pH of a neutral solution are familiar to those in the art, and are within the scope of the present invention. Those alkalinity agents that are both found in nature and biodegradable are preferred. Sodium sesquicarbonate  140 , which includes sodium bicarbonate and sodium carbonate in an approximately 1:1 ratio, is presently preferred because it occurs in nature and is completely biodegradable. 
     The softener  134  should preferably be selected to exchange soluble sodium or other ions for the insoluble calcium and magnesium ions. Those softeners that are both found in nature and biodegradable are preferred. A cleaning composition  11  wherein the softener  134  is natural zeolite  142  (Na 2 O.Al 2 O 3 .(SiO 2 ) x .(H 2 O) x ) is presently preferred because it occurs in nature and is completely biodegradable. 
     In one embodiment of the present invention, the cleaning composition  11  is intended to be dissolved in an apparatus for delivering solvated cleaning agents, wherein the cleaning composition  11  reaches equilibrium concentration before being flushed into a cleaning chamber and diluted to cleaning concentration. Therefore, the amount of each component in the cleaning composition  11  is preferably tailored to this purpose. 
     The amount of gas-releasing agent  128  in the cleaning composition  11  determines how much gas is released in a cleaning solution  17  of the cleaning composition  11  formed when the cleaning composition  11  dissolves in a solvent, e.g., water. Therefore, the gas-releasing agent  128  in the cleaning composition  11  should comprise an amount sufficient to release a predetermined amount of gas in a cleaning solution  17  of the cleaning composition  11 . A concentration of gas-releasing agent  128  from 20% to 60% by weight of the cleaning composition  11  is preferred. In one embodiment, the concentration of gas-releasing agent  128  is from 35% to 45% by weight. 
     The amount of solubility control agent  130  in the cleaning composition  11  determines the equilibrium concentration of the cleaning composition  11  in the cleaning solution  17 . Therefore, the amount of solubility control agent  130  in the cleaning composition  11  should be selected to yield a predetermined equilibrium concentration of cleaning composition  11  in the cleaning solution  17 . A concentration of solubility control agent from 5% to 35% by weight of the cleaning composition  11  is presently preferred. In one embodiment, the concentration of solubility control agent is about 20% by weight to yield an equilibrium concentration of the cleaning composition  11  that is approximately 0.12% by weight in water. The amount of alkalinity  132  agent in the cleaning composition  11  affects the pH of the cleaning solution  17 . Therefore, the cleaning composition  11  should include an amount of alkalinity agent  132  selected to provide a cleaning solution  17  with a predetermined pH. A concentration of alkalinity agent  132  from 1% to 10% by weight of the cleaning composition  11  is presently preferred. In one embodiment, the concentration of alkalinity agent  132  is about 3% by weight, providing a cleaning solution  17  with a pH of about 8.8 after dilution inside the cleaning appliance  16 . 
     The softener  134  in the cleaning composition  11  softens the cleaning solution  17  by scavenging residue-forming ions. Therefore, the softener  134  should comprise an amount of cleaning composition  11  sufficient to soften household water. A concentration of softener  134  from 1% to 20% by weight of the cleaning composition  11  is presently preferred. In one embodiment, the concentration of the softener  134  is about 8% by weight. 
     Water molecules may form complexes with these components and could be bound up within the cleaning composition  11  by virtue of the process of making the cleaning composition  11 . Water may comprise from 1 to 50% of the cleaning composition  11  by weight. Preferably, water comprises approximately 20% by weight of the cleaning composition  11 . 
     Referring to FIG. 14, after the items to be cleaned are exposed to the cleaning solution  17  in the fifth step  122  described in conjunction with FIG. 10, a number of processes occur. The basic cleaning solution  17  attacks the acids in dirt and oil. In a first reaction step  144 , the gas-releasing agent  128  reacts with dirt and oil. In a gas-releasing step  146 , gas is released. In a cleaning appliance  16  for washing clothing, dirt and oil would be dislodged from clothing in a removal step  148  due to reaction and the sudden release of gas. In a second reaction step  150 , the gas-releasing agent  128  continues to react with removed soils. 
     Simultaneously, in a scavenging step  152 , the softener  134  scavenges ions to prevent the buildup of residue on the articles to be cleaned. In addition, the alkalinity agent  154  keeps the pH of the cleaning solution  17  slightly basic. This serves two functions. First of all, it bridles the reaction of the gas-releasing agent  128  so that the gas evolves at a controlled rate and the cleaning solution  17  has time to become thoroughly intermixed with the articles to be cleaned. Second, the basic cleaning solution  17  reacts to neutralize acids in the soils. After the washing cycle is complete, the sixth step  124  described in conjunction with FIG. 10 occurs, wherein the cleaning solution  17  drains out of the cleaning appliance  16 . 
     Referring to FIG. 15, an exemplary cleaning process utilizing the exemplary cleaning concentration of FIG. 14 is shown. First, the sodium bicarbonate  136  and sodium sesquicarbonate  140  attack acids within the dirt and oils. The acid-base reactions have an emulsifying affect on the dirt and oils. Particularly, sodium bicarbonate  136  reacts with acids to generate carbon dioxide in an acid and base reaction: H + (aq)+NaHCO 3 (aq)→Na + (aq)+H 2 O+CO 2 (g). Most oils and dirts found in clothing are slightly acidic, and so the sodium bicarbonate  136  may react with these dirts and oils to produce carbon dioxide. This tiny explosion of gas, as it bubbles out of solution, dislodges the dirt from clothes and other materials, allowing it to be washed away. The reaction yields sodium ions in solution, or the sodium salts of the oils and dirts of the reaction, water and carbon dioxide. 
     In this embodiment, the byproducts of the cleaning process appear in nature, so there is no need for the extensive treatment of phosphates and other non-biodegradable materials, as required by presently available detergents. Some of the sodium carbonate may also react to form carbon dioxide gas according to the following equation: Na 2 CO 3 +2H + →2Na + +H 2 O+CO 2.  However, the alkalinity agent  132 , which may include sodium carbonate, is added primarily to increase the pH of the cleaning solution  17 . 
     The alkalinity agent  132  provides a mildly basic solution to prevent the sodium bicarbonate  136  from reacting with excess hydrogen ions (H+) in aqueous solution. Without the alkalinity agent  132 , CO 2  would bubble out of solution too quickly as the sodium bicarbonate  136  reacts with random hydrogen ions. With a slightly alkaline cleaning solution  17 , in one embodiment approximately 8.8 pH, the sodium bicarbonate  136  reacts at a controlled pace, and preferably with the acids in the dirts and oils. 
     The softener  134 , which may be natural zeolite  142 , exchanges sodium ions (Na+) for magnesium (Mg++) and calcium (Ca++) ions: Mg ++ +Ca ++ +zeolite→zeolite+4Na + . Sodium ions and sodium salts are readily water soluble and will not form precipitates. Without the softener, the Mg ++  and Ca ++  could react to form insoluble salts, precipitating out of solution and leaving a hard film behind, as shown by the following equations: NaHCO 3 +Mg ++ →MgCO 3 , and NaHCO 3 +Ca ++ →CaCO 3 . 
     Referring to FIG. 16, one possible method is shown for making the cleaning composition  11  in a solid state. Although FIG. 16 depicts a solvent, a gas releaser, a solubility control agent, an alkalinity agent, and a solubility control agent, the cleaning composition  11  may be manufactured without these components or with additional, unnamed agents. 
     In a solvent step  168 , a solvent for dissolving the other agents is provided. In a gas-releasing agent step  170 , a gas-releasing agent  128  is added to the solvent. In a softener step  172 , a softener  134  is added to the solvent. In a solubility control agent step  174 , a solubility control agent  130  is added to the solvent. In an alkalinity agent step  176 , an alkalinity agent  132  is added to the solvent. The steps  170  through  176  need not occur in the exact order described. In certain embodiments, steps  170  through  176  may occur simultaneously. 
     In a mixing step, the gas-releasing agent  128 , the softener  134 , the solubility control agent  130 , and the alkalinity agent  132  are mixed into the solvent and preferably dissolved therein, by a mixing process such as stirring. In a sealing step  180 , the entire solution is sealed within a suitable container. In a heating step  182 , the solution within the sealed container is brought to a high temperature. In a testing step,  184 , the solution is tested for an equilibrium concentration or azeotrope. In a cooling step  186 , the solution is cooled, but remains in a liquid or semi-liquid state. In a pouring step  188 , the solution is poured into a curing vessel of the appropriate size and shape to form a cartridge  30 . In a curing step  189 , the solution is allowed to cure over time. 
     Referring to FIG. 17, an exemplary embodiment of the method of FIG. 16 is shown. More specifically, the method of FIG. 17 may be directly employed to obtain the cleaning composition  11  embodied in FIG.  13 . In this illustrative method, the solvent is water. Enough water should be added to bring the mixture of components to a thick paste, such that they mix to an approximately homogenous consistency within a suitable vessel. In a water step  190 , a sodium bicarbonate step  192 , a natural zeolite step  194 , an amorphous silica step  196 , and a sodium sesquicarbonate step  198 , 29% water may be supplemented with 39% sodium bicarbonate  136 , 8% natural zeolite  142 , 21% amorphous silica  138 , and 3% sodium sesquicarbonate  140 . 
     In a mixing step  200 , the mixture may be stirred into solution. In a sealing step  202 , the solution may be sealed within an airtight container. In a heating step  204 , the solution may be heated to approximately 230° F. Testing for an equilibrium concentration or azeotrope may be performed in a testing step  206 . In a cooling step  208 , the solution may be permitted to cool to ambient temperature, while remaining in liquid or semi-liquid form. In a pouring step  210 , the solution may be poured into a curing vessel. In a curing step  212 , mixture may be permitted to cure to the solution, forming one or more properly shaped cartridges  30  of cleaning composition  11 . 
     Referring to FIG. 18, a method for making the cleaning composition  11  in a solid state, as described in connection with FIG. 16, is shown pictorially. The vessel used for mixing, heating, and cooling may be of a simple design. In the pouring step  188 , the solution may be poured into a mold with several indentations of the proper size and shape. As shown in FIG. 18, these indentations may be annular in shape to form a cartridge  30  with an annular cross section. After the curing step  189 , the cartridges  30  may be removed from the mold for use in the apparatus  10 . 
     The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.