Patent Publication Number: US-2005121057-A1

Title: System for Disinfecting Shopping Carts

Description:
FIELD OF THE INVENTION  
      The present invention is directed to shopping carts and, in particular, to the disinfection of shopping carts.  
     BACKGROUND OF THE INVENTION  
      Presently, shopping carts are rarely disinfected. Consequently, a shopping cart can present a health risk to a shopper using the shopping cart. To elaborate, organisms that present health risks can be transferred to a shopping cart from leaking meat and poultry packages, poorly fitting baby diapers, a shopper&#39;s hand or nose, and the like. These organisms can then be transmitted from the shopping cart to a shopper that subsequently uses the cart.  
      To address the health risk associated with the transfer of an organism from a shopping cart to a shopper, various systems for cleaning or disinfecting shopping carts have been devised. Many of these systems include a cleaning or disinfecting station and a transport device for moving shopping carts through the station. One system includes a mobile trailer that supports a cleaning or disinfecting station and a transport device. Another system comprises a treatment station that has multiple treatment zones and a transport system for moving the carts through the treatment zones.  
     SUMMARY OF THE INVENTION  
      The present invention provides a system for disinfecting shopping carts that may be contaminated with an organism that presents a health risk to shoppers that utilize the carts.  
      In one embodiment, the system comprises a treatment station for applying a disinfectant to a shopping cart and a conveyor system for transporting shopping carts relative to the treatment station at two different speeds to facilitate a nesting operation. To elaborate, in many instances it is desirable to provide a string of nested shopping carts to the system for processing. However, it is also desirable that the shopping carts be “un-nested” or separated from one another so that those surfaces of the carts in a string of nested shopping carts that would not be sufficiently exposed for receiving the disinfecting treatment are exposed in time to receive the disinfecting treatment. In one embodiment, the conveyor system comprises two conveyors that operate at different speeds to facilitate the “unnesting” of a shopping cart from a string of nested shopping carts. To elaborate, the conveyor system comprises a first conveyor for moving a string of nested shopping carts at a first speed and a second conveyor for moving a shopping cart at a second speed that is greater than the first speed. Initially, a string of shopping carts is placed on the first conveyor. When the lead shopping cart of the string of nested shopping carts is transferred from the first conveyor to the second conveyor, the difference in speeds of the two conveyors causes a force to be applied the lead cart that separates the lead shopping cart from the following shopping cart.  
      In other instances, it is desirable to create a string of nested shopping carts from carts that have been treated. Consequently, in another embodiment of the system, the conveyor system comprises two conveyors that operate at different speeds to facilitate the “nesting” of one treated shopping cart with another treated shopping cart. More specifically, the conveyor system comprises a first conveyor for moving an “un-nested” and treated shopping cart at a first speed and a second conveyor for moving another treated shopping cart at a second speed that is less than the first speed. In operation, the first and second conveyors are used to form a string of nested shopping carts. To elaborate, assume that a first shopping cart is on the first conveyor and a second shopping cart is on the second conveyor. When the first cart is transferred from the first conveyor to the second conveyor, the difference in speeds of the two conveyors forces the first cart towards the second cart such that the first cart nests with the second cart.  
      In yet other instances, it is desirable to: (a) “un-nest” a string of nested shopping carts so that those surfaces of the carts in the string of nested shopping carts that would not be sufficiently exposed for receiving the disinfecting treatment are exposed in time to receive the disinfecting treatment; and (b) create a string of nested shopping carts from carts that have been treated. In one embodiment, two conveyors are utilized, one conveyor being a high speed conveyor and the other conveyor being a low speed conveyor that extends beyond the ends of the low speed conveyor. The conveyors are situated so as that a shopping cart is: (a) initially engaged by the low speed conveyor; (b) then transitioned from the low-speed conveyor to the high speed conveyor to facilitate separation of the shopping cart from a string of nested shopping carts and thereby expose surfaces of the shopping cart in time to receive the disinfecting treatment; and (c) then transitioned from the high speed conveyor back to the low speed conveyor to nest the shopping cart with any previously treated shopping cart that is being transported by the low speed conveyor. In yet a further embodiment, three conveyors are utilized, two low speed conveyors that are separated from one another and a high-speed conveyor that extends between the two low speed conveyors. In this embodiment, one of the low speed conveyors and the high speed conveyor are used to facilitate the “unnesting” of a lead shopping cart in a string of shopping carts. The high speed conveyor is also used in conjunction with the other low speed conveyor to facilitate the “nesting” of one treated shopping cart with another treated shopping cart. In another embodiment of the system, the conveyor system comprises four conveyors, two conveyors for un-nesting a string of nested shopping carts and the other two conveyors for forming a string of nested carts.  
      Another embodiment of a system for disinfecting shopping carts comprises a modular treatment station and a transport system for moving a shopping cart relative to the treatment station. The treatment station defines an entry for receiving a shopping cart, an exit for providing a treated cart, and a pathway extending between the entry and the exit and along which a shopping cart travels during operation of the system. The treatment station is comprised of first and second modular units that each define a portion of the pathway and that each have a ground engagement surface. The modularity of the first and second modular units arises from the relationship of the ground structure of each of the modular units to the pathway defining structure of each of the modular units. To elaborate, these relationships are such that when the ground structures of both of the modular units are in contact with a flat surface, the portions of the pathway defined by the two units can be readily aligned with one another, thereby facilitating the joining of one unit to another. The modularity feature allows modular units that perform different functions to be designed and then readily combined with one another to realize a treatment station with the desired features for a particular application.  
      In another embodiment, modular units that have a symmetrical interface structure are employed to realize a treatment station. The symmetrical interface structure allows the modules to be concatenated with one another in a number of different sequences. For example, if a first modular unit is adapted to apply a liquid disinfectant to a shopping cart and a second modular unit is adapted to dry a shopping cart after a liquid disinfectant has been applied to the shopping cart, the symmetrical interface structure of each of the modules allows a functional treatment station to be realized in which the left-to-right order of the modules from a given view point is first module second module or second module first module. Stated differently, the symmetry characteristic of each of the modules allows: (a) a treatment station to be realized that, when the station is viewed from the side, receives shopping carts from the right hand side of the treatment station; or (b) a treatment station to be realized that, when the station is viewed from the same side, receives shopping carts from the left hand side of the treatment station.  
      A further embodiment of the system comprises a treatment station for applying a disinfectant to a shopping cart that comprises a molded structure and a transport system for moving a shopping cart relative to the treatment station. In one embodiment, the molded structure forms two or more elements of the treatment station and thereby reduces the number of components that would otherwise be required to realize the station. For example, in one embodiment, the molded structure comprises a single-piece enclosure that defines at least a portion of the pathway along which a shopping cart travels during operation of the system and a reservoir for holding the liquid disinfectant that is applied to the shopping carts. In another embodiment, the molded section forms an element that is less susceptible to damage or vandalism. For example, in one embodiment, the molded structure forms an air nozzle that is less susceptible to damage or vandalism than, for instance, metal nozzles that are attached to a supporting structure via a threaded coupling mechanism.  
      Yet another embodiment of the system comprises a treatment station that employs a low-pressure pump that is used to move disinfectant from a reservoir to an application structure that dispenses the disinfectant onto a shopping cart during operation of the system and a transport system for moving shopping carts relative to the treatment station. In one embodiment, the low-pressure pump comprises a centrifugal pump that is located, during operation of the system, at substantially the same elevation as the reservoir. This orientation of the centrifugal pump relative to the reservoir facilitates a “gravity drain” design for the system in which the disinfectant in the circuit formed by the reservoir, pump, and application structure, during operation of the system, is drawn back to the reservoir by gravity after the pump is deactivated. This “gravity drain” facilitates use of the system in cold weather applications. To elaborate, the gravity drain characteristic allows disinfectant to drain back to the reservoir when the centrifugal pump is inoperative. A heater located in the reservoir then keeps the disinfectant from freezing. In contrast, if there was not a gravity drain and a significant amount of disinfectant remained in the circuit after the pump was deactivated, the entire circuit would need to be heated to prevent the disinfectant from freezing in the circuit and rendering the system inoperative. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIGS. 1A-1D  respectively illustrate front, back, entry, and exit side views of an embodiment of a shopping cart treatment system that is configured for a right-hand cart-entry;  
       FIG. 2  is a cross-sectional view of the floor path and portions of the conveyor system associated with the transport system of the embodiment of the system illustrated in  FIGS. 1A-1D ;  
       FIGS. 3A-3C  respectively illustrate top, side and enlarged side, free body diagrams of elements of the conveyor system associated with the shopping cart treatment system shown in  FIGS. 1A-1D ;  
       FIGS. 4A-4B  illustrate the operation of the staging bar assembly associated with the conveyor system shown in  FIGS. 2A-2B ;  
       FIGS. 5A-5C  respectively illustrate a pair of modular units separated from one another and a baffle, the pair of modular units joined to one another with a baffle interposed between the units, and an alternative embodiment of a baffle;  
       FIGS. 6A-6B  illustrate the use of symmetrical and modular units to realize treatment systems that are respectively capable of receiving untreated shopping carts from the right-hand side and the left-hand side;  
       FIGS. 7A-7B  respectively are lateral and longitudinal cross-sectional views of an embodiment of a disinfectant solution delivery system suitable for use in a shopping cart treatment station;  
       FIGS. 8A-8B  respectively are lateral and longitudinal cross-sectional views of another embodiment of a disinfectant solution delivery system suitable for use in a shopping cart treatment station;  
       FIG. 9  is a longitudinal cross-sectional view of a treatment station comprises of a recycling liquid disinfectant delivery system, a non-recycling liquid disinfectant delivery stations, and a drying system;  
       FIGS. 10A-10B  respectively are lateral and longitudinal cross-sectional views of a dryer delivery system suitable for use in a shopping cart treatment station;  
       FIG. 11  is a longitudinal cross-sectional view of a treatment station comprised of a liquid disinfectant delivery system and a dryer system;  
       FIG. 12  illustrates an embodiment of a wheeled container for use in removing spent liquid disinfectant from a liquid disinfectant delivery system and providing unused liquid disinfectant to the system;  
       FIG. 13  illustrates an embodiment of a brush system for removing particles from the wheels of shopping carts that is suitable for use with a shopping cart disinfecting system. 
    
    
     DETAILED DESCRIPTION  
      The present invention is directed to a system for disinfecting shopping carts. Generally, the system is comprised of a treatment station for applying a disinfecting treatment to a shopping cart and a transport system for moving a shopping cart relative to the treatment station.  
       FIGS. 1A-1D  illustrate an embodiment of a system for disinfecting shopping carts, hereinafter referred to as system  20 . The system  20  comprises a treatment station  22  for applying a disinfecting treatment to a shopping cart and a transport system  24  for moving a shopping cart relative to the treatment station.  
      The treatment station  22  defines an entry threshold  28 A, exit threshold  30 B, and a pathway  30  that extends between the entry threshold  28 A and exit threshold  28 B and through which the shopping carts pass during treatment.  
      The transport system  24  is capable of: (a) receiving a single shopping cart and moving the shopping cart over the pathway  30  defined by the treatment station  22 ; (b) receiving multiple shopping carts that are sufficiently separated from one another so that no further separation is needed to sufficiently expose the surfaces of the cart to the disinfecting treatment provided by the treatment station  22  and moving each of the shopping carts over the pathway  30  defined by the treatment station  22 ; (c) receiving a string of nested shopping carts, separating the nested shopping carts from one another so that the surfaces of each of the shopping carts that would not otherwise be sufficiently exposed for receiving a disinfecting treatment are sufficiently exposed in time to receive the disinfecting treatment, nesting treated shopping carts with one another, and moving each of the shopping carts over the pathway  30  defined by the treatment station  22 . It should be appreciated that when the term “nested” or a similar term is used with respect to shopping carts that have not been treated, the term means that the shopping carts are not sufficiently separated from one another so that the surfaces of each of the shopping carts is sufficiently exposed for receiving a disinfecting treatment. Consequently, nested shopping carts may or may not be in physical contact with one another. Concomitantly, the term “un-nesting” means that the untreated shopping carts are separated from one another such that the surfaces of each shopping cart are sufficiently exposed for receiving a disinfecting treatment. It should also be appreciated that when the term “nesting” or similar term is used with respect to treated shopping carts, the term means that the carts are sufficiently close to one another that the surfaces of each of the shopping carts are not sufficiently exposed for receiving a disinfecting treatment.  
      The transport system  24  comprises a floor structure  36  that defines the path over which a shopping cart travels during processing by the system  20  and a conveyor system  38  for moving a shopping cart over at least a portion of the floor structure  36 . The floor structure  36  extends from a first floor end  40 A to a second floor end  40 B. Further, the floor structure  36  comprises an incline section  42 A up which a shopping cart is moved prior to treatment, a decline section  42 B down which a shopping cart rolls after treatment, and a raised section  42 C that extends between the incline section  42 A and decline section  42 B. With reference to  FIG. 2 , the floor structure  36  comprises a bottom surface  44  that engages wheels associated with a shopping cart and a pair of side rails  46 A,  46 B that serve to guide a shopping cart over the floor structure  36 . Associated with the bottom surface  44  are a pair of raised platforms  45 A,  45 B that support the rear wheels of a shopping cart when the shopping cart has been engaged by the conveyor system  36  to assure that the axes of the front and rear wheels remain in a substantially level plane that facilitates nesting operations.  
      With continuing reference to  FIG. 2 , the conveyor system  38 , in addition to moving a shopping cart over at least a portion of the floor structure, facilitates: (a) the separation of nested shopping carts from one another so that the surfaces of each shopping cart are sufficiently exposed in time to receive the disinfecting treatment; and (b) the nesting of treated shopping carts with one another. The separation of nested shopping carts and nesting of treated shopping carts is facilitated by using two conveyor belts that, during operation, move at different speeds. To elaborate, the separation of nested shopping carts is facilitated by causing the lead shopping cart of a group of nested shopping carts to transition from the slower of the two conveyor belts to the faster of the first two conveyor belts. The difference in the speed facilitates the separation of the lead shopping cart from the following shopping cart. The nesting of treated shopping carts is facilitated by causing a shopping cart to transition from the faster of the two conveyor belts to the slower of the two conveyor belts. If another shopping cart is already on the slower of the first and second conveyor belts, the difference in speed forces the shopping cart that is transitioning from the faster conveyor belt to the slower conveyor belt to nest with the shopping cart that is already on the slower conveyor belt.  
      With continuing reference to  FIG. 2  and reference to  FIGS. 3A-3C , the conveyor system  38  comprises: (a) first and second conveyor belt systems  48 A,  48 B; (b) a drive system  50  for transmitting power to the first and second conveyor belt system  48 A,  48 B so that a belt associated with the first convey belt system  48 A moves at a first speed and a belt associated with the second conveyor belt system  48 B moves at a second speed that is greater than the first speed; and (c) a housing  52  for supporting elements of the first and second conveyor belt systems  48 A,  48 B.  
      The first conveyor belt system  48 A comprises a pair of grooved pulleys  54 A,  54 B and a belt  56  that extends between the pulleys  54 A,  54 B and is used to engage a shopping cart. Similarly, the second conveyor  48 B comprises a pair of grooved pulleys  58 A,  58 B and a belt  60  that extends between the pulleys  58 A,  58 B and is used to engage a shopping cart. Tensioning of each of the belts  56 ,  60  is accomplished with an idler pulley (not shown). As shown in  FIG. 3A , the first conveyor belt system  48 A extends from a first end that is defined by the grooved pulley  54 A to a second end that is defined by the grooved pulley  54 B. Similarly, the second conveyor belt system  48 B extends from a first end that is defined by the grooved pulley  58 A to a second end that is defined by the grooved pulley  58 B. Further, the first and second ends of the second conveyor belt system  48 B are located between the first and second ends of the first conveyor belt system  48 A.  
      The drive system  50  comprises: (a) an electric motor  62  that is used to provide the power that is used to drive the first and second conveyor belt systems  48 A,  48 B; (b) a two-groove pulley  64  that is operatively attached to the drive shaft of the electric motor  62 ; (c) a first drive belt  66  for transmitting power from the electric motor  62  to the pulley  54 A of the first conveyor belt system  48 A to drive the belt  56  at the first speed; and (d) a second drive belt  68  for transmitting power from the electric motor  62  to the pulley  58 A of the second conveyor belt system  48 B to drive the belt  60  at the second speed. The electric motor  62 , two-groove pulley  64 , first drive belt  66  and second drive belt  66  operate so that the pulleys  54 A,  58 A each rotate in a counter-clockwise direction. As a consequence, the belt  56  and the belt  60  each rotate in a counter-clockwise direction. Further, any shopping cart engaged by the belt  56  will be driven away from the first floor end  40 A and towards the second floor end  40 B. Likewise, any shopping cart engaged by the belt  60  will be driven away from the first floor end  40 A and towards the second floor end  40 B. Other drive systems for moving two conveyor belts at different speeds are feasible. For example, in another embodiment, two electric motors are utilized, one to drive the first conveyor belt system  48 A and the other to drive the second conveyor belt system  48 B. In another embodiment, the drive shaft of an electric motor is coupled to a pulley of a conveyor belt system without the use of a belt or chain.  
      The housing  52  provides mounting surfaces for the pulleys associated with the first and second conveyor belt systems  48 A,  48 B. In addition, the housing  52  also supports first and second low-friction surfaces  70 A,  70 B on which the belts  56 ,  60  respectively ride. The pulleys associated with the first and second conveyor systems  48 A,  48 B and the first and second low-friction surfaces  70 A,  70 B are mounted to the housing  52  such that when the system  20  is operational, the belt  60  is a greater distance from the bottom surface  44  than the belt  56 . In the illustrated embodiment, the pulleys  54 A,  54 B,  58 A and  58 B are all substantially the same size. Further, the pulleys  54 A,  54 B,  58 A,  58 B are mounted to the housing  52  such that when the system  20  is operational, the axes of rotation of the pulleys  58 A,  58 B are a greater distance from the bottom surface  44  than the axes of rotation of the pulleys  54 A,  54 B. Moreover, the low-friction surfaces  70 A,  70 B are of substantially the same thickness. As a consequence, a shim  72  is located between the housing  52  and the second low-friction surface  70 B to assure that the belt  60  is supported at the noted greater distance. Other approaches for positioning the belt  60  at a greater distance from the bottom surface  44  than the belt  56  are feasible. For instance, in one embodiment, pulleys of different diameters and low-friction surfaces of different thickness are employed.  
      Based on the foregoing, it should be appreciated that a shopping cart being moved by the conveyor system  38  will move in a direction away from the pulley  54 A and towards the pulley  54 B. Further, in moving in this direction, the shopping cart will be subjected to: (a) a transition from the belt  54  to the belt  60  at a point adjacent to the pulley  58 A; and (b) a transition from the belt  60  to the belt  54  at a point adjacent to the pulley  58 B. When a string of nested shopping carts is being processed by the system  20 , the transition adjacent to the pulley  58 A results in a force being applied to a lead shopping cart in the string of nested shopping carts that facilitates separation of the lead shopping cart from the following shopping cart. There is also a slight rotation of the lead shopping cart at the transition adjacent to the pulley  58 A due to the difference in heights of the belts  54 ,  60  that also facilitates the separation of the lead shopping cart from the following shopping cart. Separation of nested shopping carts is desirable so that the surfaces of each of the nested shopping carts that may not otherwise be sufficiently exposed for receiving the disinfecting treatment are sufficiently exposed in time to receive the disinfecting treatment. Consequently, the transition point adjacent to the pulley  58 A is located relative to the treatment station  22  so that nested shopping carts are separated from one another such that the surfaces of each of the nested shopping carts that may not otherwise be sufficiently exposed for receiving the disinfecting treatment are sufficiently exposed in time to receive the disinfecting treatment. The nesting of treated shopping carts is also desirable. Consequently, the transition point adjacent to the pulley  58 B is located relative to the treatment station  22  so that a treated shopping cart is forced to nest with any previously treated shopping cart that is being transported by the conveyor system  38 .  
      With reference to  FIGS. 4A-4B , the conveyor system  38  further comprises a staging bar assembly  76  that allows an operator to: (a) position one or more shopping carts over the belt  56  of the first conveyor system  48 A but prevent the one of more shopping carts from coming into contact with the belt  56 ; and (b) bring one or more shopping carts that have been positioned over the belt  56  but prevented from coming into contact with the belt  56  into contact with the belt  56 . Typically, the staging bar assembly  76  is used to facilitate batch processing of shopping carts by initially allowing a number of shopping carts to be positioned over but separated from then belt  56  and then allowing all of these shopping carts to be brought into contact with the belt  56  at substantially the same time.  
      The staging bar assembly  76  comprises a staging bar  78  with a first end  80  that is pivotally attached to the floor structure  36 , a second end  82 , an upper surface  84  for engaging one or more shopping carts, and a hook  86  for engaging a surface associated with one shopping cart. The staging bar assembly  76  further comprises an actuator  86  that allows an operator to rotate the staging bar  78  between a position at which the staging bar  78  prevents a cart or carts from contacting the belt  56  and a position at which the staging bar  78  allows a cart or carts to contact the belt  56 . The actuator  86  can be either a manual device or a device that employs electrical, hydraulic and/or pneumatic componentry.  FIG. 4A  illustrates the staging bar  78  in the position that prevents one or more shopping carts that are in contact with the upper surface  84  of the staging bar  78  from coming into contact with the belt  56 . In this position, the upper surface  84  prevents the surface of a shopping cart that would otherwise come into contact with the belt  56  from contacting the belt  56 . In this position, the hook  86  also prevents the shopping cart that is located closest to the hook  86  from coming into contact with the belt  56  by sliding off of the second end  82  of the staging bar  76 . As a consequence, any other carts that are engaged by the staging bar  78  are also prevented from coming into contact with the belt  56  by sliding off of the second end  82  of the staging bar  76 . In  FIG. 4B , the staging bar  78  is in the position that allows shopping carts to engage the belt  56 . Other staging bar assemblies are feasible. For instance, a staging bar assembly with a staging bar that is linearly translated, rather than rotated, is feasible. Also feasible is a staging bar assembly that does not prevent a shopping cart or carts from coming into contact with the belt  56  but prevents any carts from being moved by the belt  56 .  
      The conveyor system  38  is capable of being used in several different ways. For example, the conveyor system  38  is capable of being used to: (a) receive a single shopping cart and move the shopping cart through the processing station  22 ; (b) receive multiple shopping carts that are sufficiently separated from one another on the conveyor system so that no “un-nesting” is needed and post treatment nesting may not be possible, and simultaneously move the shopping carts relative to the processing station  22 ; (c) receive a string of nested shopping carts, “un-nest” the shopping carts so that surfaces of each of the shopping carts that would not otherwise be sufficiently exposed for receiving the disinfecting treatment are exposed in time to receive the treatment, nest the treated shopping carts, and simultaneously move the shopping carts relative to the processing station  22 . With respect to any of these ways of using the conveyor system  38 , the staging bar assembly  76  may or may not be utilized. However, the staging bar assembly  76  is most likely to be used when the conveyor system  38  is used to process a sting of nested shopping carts when the string of nested shopping carts is built up over time.  
      It should be appreciated that other conveyor systems that are capable of “un-nesting” and nesting operations and that utilize belts that move at different speeds are feasible. For instance, a conveyor system that utilizes a high-speed conveyor belt located between two, low speed conveyor belts is feasible. The belts can overlap with one another and have elevational differences that facilitate the transfer of a shopping cart from one belt to another, as in the conveyor system  38 . Alternatively, the belts can be placed end-to-end. In this case, elevational differences between the belts are unnecessary. Further, if necessary to prevent a shopping cart from getting stuck in the “valley” between the ends of the end-to-end conveyor belts, a rod or bar can be positioned in the “valley.” Another approach to address the “valley” between conveyors positioned end-to-end is for the second conveyor belt (i.e., the belt to which a cart is being transition) to have a “bumpy” surface that can engage the crossbar of a shopping cart that is positioned in the “valley” and thereby facilitate the transition of the shopping cart from the first conveyor belt to the second conveyor belt. Yet another approach for addressing the “valley” between end-to-end conveyors is have the first conveyor positioned so that it slopes downward towards the second conveyor. Yet a further alternative to the placement of the belts overlaps two of the three belts and situates two of the three belts end-to-end. Also feasible is a conveyor system that utilizes a first pair of conveyors (one high speed and the other low speed) to facilitate “un-nesting” and a second pair of conveyors (one high speed and the other low speed) to facilitate nesting. Again, overlapping, end-to-end and combinations of overlapping and end-to-end belts are feasible.  
      It should also be appreciated that although the conveyor system  36  is capable of both “un-nesting” and nesting operations, certain applications may only require a conveyor system that is capable of facilitating one of the “unnesting” and nesting operations. For example, a conveyor system that is only capable of “un-nesting” untreated shopping carts would be appropriate when the user does not want the treated carts to be nested or the treated carts are nested in some other manner (e.g., by gravity). Similarly, a conveyor system that is only capable of “nesting” treated shopping carts would be appropriate when the carts are fed into the conveyor system such that the untreated carts are separated from one another by a distance that makes further separation unnecessary. In either case, a conveyor system that employs two belts that move at different speeds can be employed to achieve the desired nesting related function, i.e., “un-nesting” or nesting. The belts can be disposed end-to-end or overlap. If the belts overlap, the end points of the conveyor belt systems can be adjusted relative to those shown in  FIG. 3A  so that the conveyor belt systems are no longer than needed to accomplish the “un-nesting” or nesting operation.  
      It should be further appreciated that a conveyor system that uses belts that move at different speeds to perform nesting and/or un-nesting operations is not limited to any particular treatment station but can be used with many different types of treatment stations.  
      With reference to  FIGS. 1A-1B , the treatment station  22  is comprised of three modular units  100 A- 100 C. The modular units  100 A- 100 B are for use in applying a liquid disinfectant to a shopping cart. The modular unit  100 C is for use in blowing warm air onto a shopping cart to which a liquid disinfectant has been applied to dry the shopping cart. The modularity of the units  100 A- 100 C is realized by designing each of the units  100 A- 100 C such that each unit defines a portion of the pathway  30  and that the portion of the pathway that each unit defines can be readily aligned with a portion of the pathway defined by another unit. The ability to readily align the portions of the pathway defined by each of the units is achieved at least in part by, when two units are positioned on a reference surface, defining an end of the portion of the pathway defined by one unit and an end of the portion of the pathway defined by the other unit so that the ends are capable of being juxtaposed so as to form a greater portion of the pathway. In the illustrated embodiment, the ability to readily align the portions of the pathway is achieved by defining an end of a portion of the pathway defined by one unit and an end of the portion of the pathway defined by the other unit so that when the units are situated on a flat surface, the ends are capable of being brought together to form a greater portion of the pathway. This is illustrated with respect to  FIGS. 5A-5B , which shows first and second modular units  102 A,  102 B. The first and second modular units  102 A,  102 B respectively comprise first and second pathway defining surfaces  104 A,  104 B and first and second flat, ground contact surfaces  106 A,  106 B. The first pathway defining surface  104 A comprises first and second ends  108 A,  108 B and the second pathway defining surface  104 B comprises first and second ends  110 A,  110 B. As shown in  FIG. 5B , when the first and second modular units  102 A,  102 B are brought together such that the first and ground contact surfaces  106 A,  106 B are co-planar, the second end  108 B of the first modular unit  102 A and the first end  110 A of the second modular unit  102 B are capable of being aligned so as to form a greater portion of the pathway than was defined by either unit separately. Typically, the modular units  102 A,  102 B will not be positioned on a perfectly flat surface. To address this possibility, each of the units comprises adjustable legs (not shown) that are associated with the ground contact surfaces  106 A,  106 B. The first and second modular units  102 A,  102 B also respectively comprises first and second outer surfaces  112 A,  112 B that are substantially identical to one another. As a consequence, when the first and second units  102 A,  102 B are brought together, as shown in  FIG. 5B , the first and second outer surfaces  112 A,  112 B form a larger outer surface that has the same shape as the first and second outer surfaces  112 A,  112 B. 
          it should be appreciated that, while the treatment station  22  shown in  FIGS. 1A-1D  is comprised of the three modular units  100 A- 100 C, a treatment station comprised of two or more modular units is feasible. Additionally, modularity allows units that perform different functions to be designed and readily concatenated with other units to form a treatment station that meets the requirements for a particular application. Further, if desired, modules with “keyed” end surfaces that only allow modular units to be joined to one another in a specific sequence are feasible.        

      Further, while the first and second pathway defining surfaces  104 A,  104 B are shown as being closed-loop surfaces, it should be appreciated that modules with pathway defining surfaces that are not closed-loop surfaces are feasible. Stated differently, modules are feasible that when joined to one another do not form a tunnel-like pathway along which the shopping carts pass but form a pathway that is exposed to the environment. It should also be appreciated that a treatment station comprised of modular units is capable of being used with or adapted for use with a transport system other than a transport system that employs conveyors that move at different speeds.  
      The interface structures of at least two of the two or more modular units comprising a treatment station are symmetrical with respect to a lateral plane that is located midway between the ends of the modular units and that is substantially perpendicular to the direction in which shopping carts move along the pathway. As a consequence, the modular units have interface symmetry that allows the unit to be concatenated with one another in a number of different sequences. With reference to  FIG. 1B , the symmetry of the modular unit  100 C is described. Modular unit  100 C is comprised of first and second ends  116 A,  116 B and an interior surface that defines a portion of the pathway  30  (which are comparable to the first and second ends  108 A,  108 B and the first pathway defining surface  104 A of the first modular unit  102 A). The portion of the pathway  30  defined by the interior surface comprises a floor surface  118 . A lateral plane  120  is located midway between the first and second ends  116 A,  116 B and substantially perpendicular to a direction  122  in which shopping carts move along the pathway  30 . The end  116 A and the end  116 B are each capable of being readily aligned with other modular units and are symmetrical relative to the lateral plane  120 . Consequently, the modular unit  100 C is capable of taking different positions relative to other modular units in a treatment station. The other modular units  100 A,  100 B also have this symmetrical interface structure characteristic. As a consequence, these units are also capable of taking different positions relative to other modular units in a treatment station. For instance,  FIG. 6A  shows the treatment station  22  with a right-to-left sequence of modular units of modular unit  100 A, modular unit  100 B, and modular unit  100 C. With this right-to-left sequence of modular units, the treatment station  22  is set up to receive untreated shopping carts from the right-hand side.  FIG. 6B , in contrast, shows a treatment station  126  with a right-to-left sequence of modular unit of modular unit  100 C, modular unit  100 B, and modular unit  100 A. With this right-to-left sequence of modular units, the treatment station  126  is set up to receive untreated shopping carts from the left-hand side. As can be appreciated, the ability to create a treatment station that facilitates either right or left hand entry provides flexibility in locating a treatment system that employs modules with symmetrical interface structures. Again, it should be appreciated that, while the treatment station  22  shown in  FIGS. 1A-1D  is comprised of the three modular units  100 A- 100 C that each have the symmetrical interface characteristic, a treatment station comprised of two or more modular units is feasible.  
      One or more internal elements (i.e., a structure located between the ends of the module) of a module comprising a treatment station are also symmetric relative to a midlateral plane. Among these internal elements are those elements that if not symmetric relative to the plane would affect a shopping cart differently during operation of the system depending upon whether the cart entered the module unit through one end or the end of the module. In the case of the modular unit  100 C, which is used in drying carts that have been treated with a liquid disinfectant, the elements of the unit that are symmetric relative to the plane  120  are those elements that if not symmetric relative to the plane would affect a shopping cart differently during operation of the system depending upon whether the shopping cart entered the unit through the first end  116 A or the second end  116 B. One element of the modular unit  100 C that is symmetrically located is the group of nozzles that are used to disperse air onto treated shopping carts to dry the carts. If the group of nozzles was not symmetrically located relative to the plane, shopping carts would be engaged by the air stream projected by the nozzles at different times depending upon whether the cart entered the modular unit  1003  from the first end  116 A or the second end  116 B.  
      At least one of the modular units associated with a treatment station comprises a one-piece, molded plastic structure that comprises two or more elements needed to implement that function of the modular unit in a treatment station. For instance, a modular unit for use in applying a liquid disinfectant to a shopping cart may comprise a one-piece, molded plastic structure that comprises: (a) an enclosure that shields a shopping cart from wind, rain and other environmental factors that could adversely affect the application of a disinfectant to the cart; (b) a reservoir for holding the disinfectant that is to be applied to a cart; and (c) a structure for use in dispersing disinfectant onto a cart, such as a hanger that supports a manifold that is used to disperse disinfectant onto a cart. A modular unit for use in applying warm air to a shopping cart to dry the shopping cart after the application of a liquid disinfectant to the shopping cart may comprise a one-piece, molded plastic structure that comprises: (a) an enclosure that shields a shopping cart from wind, rain and other environmental factors that could adversely affect the application of air to the cart; and (b) one or more nozzles that are used to apply air to a cart. The use of a one-piece, molded plastic structure to realize two or more element reduces the part count of a module and, in some cases, renders the module less susceptible to vandalism.  
      Potentially associated with a modular unit is a component cabinet for housing certain components that are used in conjunction with the modular unit to provide a function associated with treating a shopping cart. With reference to  FIGS. 1A-1D , a first cabinet  130 A is associated with the modular units  100 A- 100 B and a second cabinet  130 B is associated with modular unit  100 C. Since the modular units  100 A,  100 B serve to facilitate the application of a liquid disinfectant to shopping carts, the first cabinet  130 A typically houses components that are used in the application of the liquid disinfectant. For instance, the first cabinet  130 A may house a pump that is used to move disinfectant from a reservoir to a dispersal system, a control system for controlling the operation of the pump and possibly controlling other elements of the system  20  (e.g., the transport system  24 ), and an operator interface that allows an operator to interact with the control system. The modular unit  100 C serves to facilitate the application of high-pressure air to shopping carts that have been treated with a liquid disinfectant to dry the carts. Consequently, the second cabinet  216 B houses components that are used in the application of high-pressure air to the carts. For instance, the second cabinet  216 B may house a heater-blower device, a control system for controlling the operation of the heater-blower device and possibly other elements of the system, and an operator interface that allows an operator to interact with the control system. It should be appreciated that a component cabinet can be associated with only one modular unit or with multiple modular units. Moreover, a component cabinet associated with one modular unit does not necessarily need to be attached to that modular unit. Further, if a cabinet is associated with a modular unit and attached to the modular unit, the cabinet is designed so as not to interfere with the modular features of the modular unit. Similarly, if a cabinet is associated with two or more modular units that are joined with one another or are to be joined with one another and the cabinet is to be attached to the joined modular units, the cabinet is designed so as not to interfere with any modular features of the joined modular units.  
      One or more modular units can be combined with components that are not integral to a modular unit and one or more enclosures to form a treatment system for use in a treatment station. A treatment station is comprised of one or more treatment systems. If a treatment station is comprised of two treatment systems, the systems can be modular and have symmetrical interfaces that allow the systems to be concatenated in different orders. For example, the treatment system  22  is comprised of: (a) a liquid disinfectant delivery system comprised of modular units  100 A- 100 B, enclosure  130 A, and related components; and (b) a drying station comprised of modular unit  100 C, enclosure  130 B, and related components. As shown in  FIGS. 6A-6B , these two systems each have interface symmetry that allows them to be concatenated in two different orders. It should be appreciated that a modular unit that lacks an enclosure and/or lack components other than the components provided by the modular unit may, in certain applications, constitute a treatment system.  
      The following describes a number of embodiments of systems that are suitable for use in a treatment station. Each system is comprised of at least one modular unit, an enclosure, and related components that are not integral to a modular unit. Each modular unit has interface symmetry. As a consequence, each system has interface symmetry. Further, each modular unit is comprised of a molded plastic structure that provides at least two components or elements relating to the function of the module.  
      With reference to  FIGS. 7A-7B , an embodiment of a liquid disinfectant delivery system  140  is described. The liquid disinfectant delivery system  140  is comprised of: (a) a modular unit  142  that is designed to facilitate the application of a liquid disinfectant to a shopping cart; (b) an cabinet  144  for housing components associated with applying a liquid disinfectant to a shopping cart; and (c) a closed-loop, liquid disinfectant transport system  146  for moving liquid disinfectant from a reservoir to a structure for dispersing disinfectant onto a shopping cart.  
      The modular unit  142  comprises a pathway defining surface  148  that defines a pathway  150 . The pathway of  150  of modular unit  142  is capable of being readily aligned with the pathway associated another modular unit (as exemplified in  FIGS. 5A-5B ) to form a greater portion of a pathway of a treatment station comprised of modular units, such as treatment station  22 . In this regard, the pathway defining surface  148  comprises first and second ends  152 A,  152 B that are symmetrical about a lateral plane  154  that is located midway between the first and second ends  152 A,  152 B. The modular unit  142  further comprises a substantially flat, ground contact surface  156 . When the substantially flat, ground contact surface  156  is co-planar with the substantially flat ground contact surface of another modular unit, at least one of the first and second ends  152 A,  152 B can be aligned with an end that is associated with the other modular unit.  
      The modular unit  142  comprises: (a) an enclosure  158  for shielding a shopping cart from environmental factors that could adversely affect the application of disinfectant to a shopping cart; (b) a reservoir  160  for holding the liquid disinfectant that is to be applied to a cart; and (c) a hanger  162  for supporting a perforated tube that is used to disperse the liquid disinfectant onto a shopping cart. The enclosure  158 , reservoir  160 , and hanger  162  are each symmetrical about the lateral plane  154 . Further, the modular unit  142  is a one-piece plastic structure that provides the enclosure  158 , reservoir  160  and hanger  162 .  
      The cabinet  144  houses components of the closed-loop, liquid disinfectant transport system  146  and is attached to the modular unit  142  at mounting points  164 A- 164 C.  
      The closed-loop, liquid disinfectant transport system  146  for moving liquid disinfectant from a reservoir to a structure for dispersing disinfectant onto a shopping cart is comprised of: (a) a filter  166  located in the space defined by the reservoir  160 ; (b) a suction tube  168  with a first end that is operatively attached to the filter  166  and a second end for operatively engaging a pump; (c) a low-pressure centrifugal pump  170  with an inlet for operatively engaging the second end of the suction tube  168  and an outlet for operatively engaging a spray tube; and (d) a spray tube  172  for dispersing liquid disinfectant onto a shopping cart and having one end operatively connected to the outlet of the pump  170  and a second end that is operatively connected to the hanger  162 . The pump  170  is substantially located within the cabinet  144 . Further, the inlet of the pump  170  is located adjacent to the ground contact surface  156  to assure that, during operation, the inlet is below the surface of the liquid disinfectant held in the reservoir  160 . In operation, the pump  170  pulls liquid disinfectant out of the reservoir  160  via the filter  166  and suction tube  168  and pushes the liquid disinfectant drawn out of the reservoir  160  through the spray tube  172 . The liquid disinfectant is discharged through rations  174  in the spray tube  172  and onto a shopping cart located between the first and second ends  152 A,  152 B. Liquid disinfectant that either does not engage a shopping cart or drips off of a shopping cart passes through holes in the floor structure and a hole  176  defined by the reservoir  160  to be returned to the reservoir  160  and reused. Consequently, the system  140  operates to recycle the disinfectant.  
      It should also be appreciated that the centrifugal pump  170  and the location of the inlet of the centrifugal pump  170  below the surface of the disinfectant facilitates self-draining of the system  140  when the system is not in operation. To elaborate, when the pump  170  is deactivated, gravity forces the disinfectant remaining in the spray tube  172  to drain back through the pump  170  and into the reservoir  160 . Some of the disinfectant remains in the pump  170 . As a consequence, the pump  170  is “primed” for subsequent operation. The self-draining feature is particularly beneficial in cold weather applications because the disinfectant is isolated to the reservoir  160  and the pump  170 , which has fairly intimate thermal contact with the disinfectant in the reservoir  160  via the suction tube  168 . Consequently, to prevent damage to the system  140 , it is only necessary to prevent freezing of the disinfectant present in the reservoir  160  and the pump  170 . If this were not the case, freezing would need to be prevented throughout the system. In some applications, the thermal mass of the liquid disinfectant is sufficient to keep the disinfectant in the reservoir  160  and the pump  170  from freezing. However, in other applications, it is necessary to heat the disinfectant. For such applications, the system  140  further comprises a heating element  178  for heating the disinfectant in the reservoir. If needed, a heat sink can be attached to the suction tube  168  to conduct heat from the reservoir to the pump  170 . The heating element  178  is also useful in applications in which freezing of the disinfectant is of little or no concern. In such applications, the heating element  178 , by keeping the disinfectant at or above a certain temperature, promotes the sanitizing action of the disinfectant applied to the cartsand reduces the time needed to dry a cart.  
      With reference to  FIGS. 8A-8B , another embodiment of a liquid disinfectant delivery system  180  is described. With the exception of the structure used in transporting disinfectant from a low-pressure centrifugal pump to a dispersal mechanism and the dispersal mechanism, the system  180  is substantially identical to the system  140 . As a consequence, elements of system  180  that are common to system  140  will bear the same reference numbers as the elements in system  140  and not be described further. The system  180  is comprised of: (a) a modular unit  182  that is designed to facilitate the application of a liquid disinfectant to a shopping cart; (b) a cabinet  144  for housing components associated with applying a liquid disinfectant to a shopping cart; and (c) a closed-loop, liquid disinfectant transport system  184  for moving liquid disinfectant from a reservoir to a structure for dispersing disinfectant onto a shopping cart.  
      The modular unit  182  comprises a reservoir  186  for receiving and storing disinfectant and a plurality of holes  188  for dispersing disinfectant from the reservoir  186  onto a shopping cart. The reservoir  186  and the holes  188  are symmetrical relative to the lateral plane  154 . Otherwise, the modular unit  182  is substantially identical to the modular unit  142  associated with the system  140 .  
      The cabinet  144  associated with the system  180  is substantially identical to the cabinet  144  associated with the system  140 .  
      The closed loop, liquid disinfectant transport system  184  comprises a delivery tube  190  for transporting liquid disinfect from the pump  170  to the reservoir  186 . Otherwise, the closed-loop transport system  184  is substantially identical to the system  146  associated with the system  140 . In operation, the pump  170  pulls liquid disinfectant out of the reservoir  160  via the filter  166  and suction tube  168  and pushes the liquid disinfectant drawn out of the reservoir  160  through the delivery tube  190  to the reservoir  186 . Liquid disinfectant stored in the reservoir  186  is discharged through holes  188  and onto a shopping cart located between the first and second ends  152 A,  152 B. Liquid disinfectant that either does not engage a shopping cart or drips off of a shopping cart passes through holes in the floor structure  36  and a hole  176  defined by the reservoir  160  to be returned to the reservoir  160  and reused. Consequently, the system  180  operates to recycle the disinfectant. The system  180  also provides self-draining and can include a heating element  178 .  
      With reference to  FIG. 9 , an embodiment of a non-recycling liquid disinfectant delivery system  196  is described. The liquid disinfectant delivery system  196  is comprised of: (a) first and second modular units  198 A,  198 B that are designed to facilitate the application of a liquid disinfectant to a shopping cart; (b) a cabinet (not shown) for housing components associated with applying a liquid disinfectant to a shopping cart; and (c) a closed-loop, liquid disinfectant transport system  200  for moving liquid disinfectant from a reservoir to a structure for dispersing disinfectant onto a shopping cart.  
      The first and second modular units  198 A,  198 B are each substantially identical to the modular unit  142 . A reservoir  202  associated with the first modular unit  198 A is used to hold unused liquid disinfectant. A reservoir  204  associated with the second modular unit  198 B is used to hold liquid disinfectant after the liquid disinfectant has been dispersed onto a shopping cart. The system  200  is used to pull unused liquid disinfectant from the reservoir  202  and push the disinfectant through a spray tube  206  that disperses the liquid disinfectant onto carts that are passing over the reservoir  204 . Liquid disinfectant that either does not engage a shopping cart or drips off of the shopping cart passes through holes in the floor structure  36  and a hole  208  defined by the reservoir  204  to be collected in the reservoir  204 . In other respects, the system  200  is substantially identical to the system  140  and will not be described further.  
      It should be appreciated that modular unit  182  could be used in place of either or both of first and second modular units  198 A,  198 B. Further, if modular unit  182  is used in place of modular unit  198 B, the system  200  is modified so as be substantially identical to the liquid disinfectant transport system  184 .  
      With reference to  FIGS. 10A-10B , an embodiment of a drying system  220  is described. The drying system  220  is comprised of: (a) a modular unit  222  that is designed to facilitate the application of warm air to a shopping cart that has been treated with a liquid disinfectant to dry the shopping cart; (b) a cabinet  224  for housing components associated with applying warm air to a shopping cart; and (c) heater-blower device  226  for producing moving warm air.  
      The modular unit  222  comprises a pathway defining surface  228  that defines a pathway  230 . The pathway of  230  of modular unit  222  is capable of being readily aligned with the pathway associated another modular unit (as exemplified in  FIGS. 5A-5B ) to form a greater portion of a pathway of a treatment station comprised of modular units, such as treatment station  22 . In this regard, the pathway defining surface  228  comprises first and second ends  232 A,  232 B that are symmetrical about a lateral plane  234  that is located midway between the first and second ends  232 A,  232 B. The modular unit  222  further comprises a substantially flat, ground contact surface  236 . When the substantially flat, ground contact surface  236  is co-planar with the substantially flat ground contact surface of another modular unit, at least one of the first and second ends  232 A,  232 B can be aligned with an end that is associated with the other modular unit.  
      The modular unit  222  comprises: (a) an enclosure  238  for shielding a shopping cart from environmental factors that could adversely affect the application of warm air to a shopping cart; (b) a plenum  240  for receiving warm air from the heater-blower device  226 ; and (c) a plurality of outlet nozzles  242  that receive warm air from the plenum  242  and direct the warm air onto a shopping cart. The plenum  242  assures that each of the nozzles  242  receives warm air at substantially the same pressure. The enclosure  238 , plenum  242 , and plurality of outlet nozzles  242  are each symmetrical about the lateral plane  234 . Further, the modular unit  222  is a one-piece plastic structure that provides the enclosure  238 , plenum  242 , and plurality of nozzles  242 .  
      The cabinet  224  houses components of the heater-blower device  226  and is attached to the modular unit  222  at mounting points  244 A- 244 C.  
      The heater-blower device  226  is comprised of a blower  246 , a heater  248 , and a duct  250  for directing heated and blown air into the plenum  240 . The blower  246  is comprised of an electric motor  252 , a fan  254 , and a fan belt  256  that couples the motor  252  to the fan  254 . In operation, the blower  246  drives air across the heater  248 , which heats the air, and through the duct  250  into the plenum  240 . The plenum  240  then provides the pressurized and warm air to the plurality of nozzles  242 , which direct the air onto any shopping cart that is in the passageway  230 .  
      It should be appreciated that other kinds of treatment systems are feasible. For instance a treatment system that irradiates a shopping cart with electromagnetic radiation, such as ultraviolet light, is feasible.  
      As should be appreciated, a treatment system can be combined with other treatment systems to form a treatment station, such as treatment station  22 . If a treatment station is comprised of two treatment systems, the systems can be modular and have symmetrical interfaces that allow the systems to be concatenated in different orders. For example, the treatment system  22  is comprised of: (a) a liquid disinfectant delivery system comprised of modular units  100 A- 100 B, enclosure  130 A, and related components; and (b) a drying station comprised of modular unit  100 C, enclosure  130 B and related components. As shown in  FIGS. 6A-6B , these two systems each have interface symmetry that allows them to be concatenated in two different orders. It should be appreciated that a modular unit that lacks an enclosure and/or lack components other than the components provided by the modular unit may, in certain applications, constitute a treatment system.  
      The following describes a number of embodiments of a treatment station comprised of two or more treatment systems. Each system is comprised of at least one modular unit, an enclosure, and related components that are not integral to a modular unit. Each modular unit has interface symmetry. As a consequence, each treatment system has interface symmetry.  
      With reference to  FIG. 11 , an embodiment of a treatment station  270  is described. The treatment station  270  is comprised of: (a) a liquid disinfectant delivery system  272  that is substantially identical to one of liquid disinfectant delivery systems  140 ,  180 ; and (b) a dryer system  274  that is substantially identical to the dryer system  220 .  
      With reference to  FIG. 1A , treatment station  22  is comprised of (a) a liquid disinfectant system  278  that is comprised of modular units  100 A,  100 B; and (b) a dryer system  274  that is substantially identical to dryer system  220 . The two modular units  100 A,  100 B and related components can implement a non-recycling disinfectant delivery system that is substantially identical to non-recycling disinfectant delivery system  196 . Alternatively, each of the modular units  100 A,  100 B can be substantially identical to one of liquid disinfectant delivery system  140 ,  180 . Such an implementation would allow a shopping cart to be treated with two different disinfectants.  
      With reference to  FIG. 9 , a treatment station  284  is described. Treatment station is comprised of: (a) a recycling liquid disinfectant delivery system  286  that is substantially identical to one of liquid disinfectant system  140 ,  180 ; (b) the non-recycling liquid disinfectant delivery system  196 ; and (c) a dryer system  288  that is substantially identical to the dryer system  220 .  
      As can be appreciated from the foregoing, treatment stations that have two or more recycling liquid disinfectant delivery systems and/or two or more non-recycling liquid disinfectant delivery systems are feasible. Further, treatment stations with two or more dryer systems are feasible. Typically, at least one of the dryer systems would be located between two liquid disinfectant delivery systems. If open, air-drying of treated shopping carts is feasible, a treatment station without a dryer system is also feasible.  
      With reference to  FIG. 5B , if the modular unit  112 A is for use in a liquid disinfectant delivery system that disperses a liquid disinfectant onto a cart and modular unit  112 B is for use in a dryer system that dries a shopping cart after a liquid disinfectant has been applied to the cart via modular unit  112 A, the operation of the dryer system may blow air through the modular unit  112 A that drives liquid disinfectant out of the modular unit  112 A before the liquid disinfectant can disinfect a cart. To prevent this from occurring, an embodiment of treatment station comprises a baffle  292  that is interposed between the modular unit  112 A and the modular unit  112 B. Alternatively, with reference to  FIG. 5C , a two-piece baffle  294  is employed.  
      The removal of used liquid disinfectant from a liquid delivery system and replenishment of the system with new liquid disinfectant is occasionally necessary. To facilitate removal of used liquid disinfectant from a recycling liquid disinfectant delivery system, a diverter valve is placed on the outlet side of the pump so that the liquid disinfectant can be diverted away from the dispersal device and into a suitable container. With reference to  FIG. 7A , the embodiment of a liquid disinfectant delivery system  140  comprises a diverter valve  298  that allows liquid disinfectant to be diverted from the spray tube  172  to a suitable container. With respect to the non-recycling liquid disinfectant delivery system  196  illustrated in  FIG. 9 , removal of used liquid disinfectant is accomplished using: (a) a first diverter valve, like diverter valve  298 , that is located on the outlet side of the pump; and (b) a second diverter valve that is located on the inlet side of the pump and allows the pump to be switched between pumping unused liquid disinfectant from reservoir  202  or used liquid disinfectant from reservoir  204  via appropriate tubing. By appropriately setting the first and second diverter valves, the used liquid disinfectant can be removed from reservoir  204 . With reference to  FIG. 12 , an embodiment of a container system  300  for transporting liquid disinfectant is described. The container system  300  is a comprised of a container body  302  for holding liquid disinfectant, a frame  304  that is attached to the container body  302 , a handle  306  that is attached to or part of the frame  304 , a pair of wheels  308  that are attached to the frame  304 , and a spigot  310  that allows the container body  302  to be drained. The container system  300  is sized to fit within the cabinet  144 . When spent disinfectant is to be removed from the system, the diverter valve  298  is actuated so that the spent disinfectant being pumped by the pump  170  flows into the container body  302 . The container system  300  is used to transport the spent liquid disinfectant to a suitable disposal site where the spigot  310  is opened and the container body  302  is emptied of the spent disinfectant. Typically, the container body  302  will then be cleaned, filled with new liquid disinfectant, and transported back to the system. Once at the system, the spigot is opened adjacent to the hole  176  and the new disinfectant is discharged into the reservoir  160  via the hole  176 .  
      Often the wheels of shopping carts pick up particles, such as rock pebbles, from the parking lot and similar area. The particles frequently damage the floor of the store. With reference to  FIG. 13 , an embodiment of a system for disinfecting shopping carts also comprises a brush system  314  for removing particles from the wheels of shopping carts is described. The brush system  314  is comprised of one or more brush surfaces that move transverse to the direction in which the carts are moving over the floor structure  36 . By having the brush surfaces move at an angle that is other than perpendicular to the direction in which the carts are moving, the brushes force the wheels to rotate so that most if not all of the floor contacting surface of each of the wheels is contacted by the brush.  
      With reference to  FIG. 6B , if desired, a fence structure  318  can be located adjacent to the second floor end  40 B to control and restrict the movement of treated shopping carts discharged from the treatment station  22 .  
      In certain applications, the shopping carts that are to be processed by a system for disinfecting shopping carts may be particularly dirty. For instance, shopping carts may become caked with mud when used to transport goods to automobiles located in dirt parking lots that become muddy after a rain or snow storm. In such situations, it is desirable to remove the mud or other debris from the shopping cart and to do so before subjecting the cart to a disinfecting treatment. For such applications, the system for disinfecting shopping carts further comprises a power wash system before the first disinfectant system. On embodiment of the power wash system comprises a reservoir, a hand held spray wand for use by an operator, and pressurization system to pressurize the water for the spray wand. In another embodiment, a power spray station positioned adjacent to the transport system is used to power wash carts as they move along the transport system. For cold weather applications, the water can be treated with anti-freeze.