Patent Publication Number: US-2020282959-A1

Title: High pressure chemical foamer for commercial car washing systems

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of U.S. provisional patent application No. 62/815,807, filed on Mar. 8, 2019, entitled “Two-Stage Eduction High Pressure Chemical Foamer for Commercial Car Washing”, the entirety of which is incorporated herein by reference in its entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to vehicle wash systems, and in particular, to chemical solution application and foam volumizing devices for use in vehicle wash systems, and more specifically, to chemical applicators and foamers for commercial carwashing systems. 
     BACKGROUND 
     According to the United States Census Bureau, over 100,000 car wash facilities are located in the United States with consumers spending approximately $5.8 billion. These facilities include tunnel type, where vehicles are pulled through a long narrow building on a conveyor so as to be exposed to various wash components for processing the vehicle exterior. Other facilities are of the self-service type, where the car is pulled into a wash bay, the customer remits payment at a payment station, and then manually washes the car using high pressure wands and brushes. Still other types of facilities include in-bay automatic washes (commonly found in conjunction with convenience stores) where payment is made at a payment station and, the vehicle is driven into and parked inside of a wash bay, and once in the wash bay, the wash unit moves back and forth over the vehicle to carry out various wash functions. 
     The above-described systems typically utilize one or more air compressors to generate foam for volumizing cleaning and conditioning chemicals for eventual application onto vehicles. The chemicals are volumized for several reasons. For example, when the chemicals, especially cleaning detergents, are volumized, they cause the chemical application to stick to the surface of the vehicle long enough for a thorough wash process to take place. Additionally, the foam expansion of the chemical provides the customer a clear visual display to verify that product has been applied to the vehicle. For these and other reasons, foaming chemicals is extremely important to the success of a carwash. 
     However, such air compressors are expensive to operate, are bulky (a typical size including an 80 gallon storage tank), and require motors to drive reciprocating piston pumps to compress the air. All of this equipment requires extra space in an equipment room, are costly to operate, expensive to repair, difficult to installs, and are noisy during operation. Furthermore, the resulting condensed water vapor generated during operation must be frequently drained. In view of the foregoing, air compressors are generally regarded as an inconvenience for carwash operators. There is a need to overcome these deficiencies. 
     SUMMARY 
     Commercial carwashing systems incorporate multiple sequential processes during operation. For example, in a first step, the vehicle is generally soaked with a cleaning detergent. The detergent is in water solution, commonly referred to as a “presoak”, where the detergent is volumized with air to produce foam. The foam is deposited in a thin even layer onto the vehicle so that the soil on the vehicle surface can be emulsified. In a second cycle step, the emulsified soil and detergent is removed from the vehicle with high pressure water. In an optional third step, the vehicle may be soaked again with a protective water-based clear coat conditioner (commonly called triple foam, lava shield, or overglow), where the conditioner is volumized with air into a foam and deposited onto the vehicle. Finally, a high pressure spot-free rinse removes the conditioner. 
     Embodiments disclosed herein provide a method of generating foam without the need of an air compressor. According to some embodiments, a pump pressurizes water to approximately 2000 psi and pushes water through the open valves, a close proximity downstream venturi type chemical injector causes the water pressure to drop approximately 60-70% past the injector to approximately 800 psi. After traveling out to the wash bay through high pressure hosing, another venturi injects ambient air into the water/solution stream just before a foaming dispersion screen, and then the final part is a pattern optimizing nozzle before deposition onto the vehicle. 
     Other aspects, features, and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of the inventions hereof. 
    
    
     
       DESCRIPTION OF THE FIGURES 
       The accompanying drawings facilitate an understanding of the various embodiments. 
         FIG. 1  illustrates a portion of a commercial car wash incorporating a chemical mixing and foam generating system in which a two-stage eduction high pressure chemical foamer is employed to advantage. 
         FIG. 2  illustrates another embodiment of portion of a commercial car wash incorporating a chemical mixing and foam generating system. 
         FIG. 3  illustrates an in-bay automatic wash system in which an embodiment of a two stage eductor high pressure foamer is employed to advantage. 
         FIG. 4  is a detail of a portion of the systems illustrated in  FIGS. 1-3 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a portion of a commercial car wash  10  incorporating a chemical mixing and foam generating system  12  in which a two-stage eduction high pressure chemical foamer is employed to advantage. In the embodiment illustrated in  FIG. 1 , system  12  includes a variable frequency drive (“VFD”) motor  40  for driving a pump  41 . A logic controller  33  is operable to, among other things, vary the speed of the motor  40  to, as discussed in greater detail below, maintain a desired fluid pressure in the system  12 . According to some embodiments, the motor  40  drives the high pressure water pump  41  to pump water from a conditioned water supply  50  at a pressure of approximately 2000 psi through a main pressure line  97 . A pair of selector valves  73  and  76  are actuated to control water flow through respective eductors  74  and  75  so as to draw in a chemical from storage drums  46  and  86 , respectively. According to some embodiments, the selector valve includes a solenoid actuated valve. In the embodiment illustrated in  FIG. 1 , storage drum  46  stores a foaming detergent and storage drum  86  stores a foaming conditioner. In a typical commercial car wash environment, for safety reasons, noise reduction, and due to limited space availability in a wash bay  32  (See  FIG. 3 ) where vehicles are washed, equipment such as, for example, the logic controller  33 , the motor  40 , the pump  41 , the eductors  74 ,  75 , the storage drums  46  and  86  and other components of the system  10  are disposed in an adjacent equipment room  29  ( FIG. 3 ) away from the wash bay  32 . 
     In operation, as the water flows through the eductors  74 ,  75 , the water pressure drops 60-70%. The water is pumped through a feed hose  96  from an “off-board” location, such as, for example, the remote equipment room  29 , where the off-board equipment is located, to a foam nozzle assembly  58 , which is “on-board” and in the proximity of a vehicle  31 , typically in the wash bay  32 . As discussed more fully below, ambient air is pulled into the nozzle assembly  58  and discharged therefrom and onto the vehicle  31  in the form of a fine foam mixture  91 . Check valves  79  and  80  prevent reverse fluid flow through the system. 
     It should be understood that the term “off-board” means at a position so as not to directly perform wash functions, such as, for example, positioned in an equipment bay/room  29 , or disposed on a wall in the wash bay  32 , or any other location not in close proximity with the wash process. It should be understood that the term “on-board” means positioned to directly perform wash functions, such as, for example, positioned in a wash bay  32  as part of a car washing machine  30 , a rinse arch  59  or otherwise in close proximity to the vehicle being washed. 
     Oftentimes, multiple chemical applications occur simultaneously. In order to accommodate the simultaneous applications, the pump being utilized is rated for the 100% maximum flow at any given moment in time; however, there may be instances where only a portion of the high pressure water is demanded from the pump. In this case, for example, if only 10% of the fluid flow volume is required, then the pump would only run 10% of rated speed. 
     In operation, the VFD pump motor  40  detects amperage draw, and based on the detected level, adjusts motor output and thus, the speed of the pump  41  so as to maintain system pressure. 
     Referring now to  FIG. 3 , a second embodiment of a system  12  is a pair of auxiliary lines  105  and  106  are branched off the high pressure line  97  and, in response to selectively operating solenoids  73 ,  76 , a portion of the water from the high pressure 76 line is directed through the correspondingly selected eductor  74 ,  75 . In operation, the eductor  74 ,  75  pulls in the chemical from the applicable drum  46 ,  86 , and the solution is directed into the low pressure intake of the high pressure pump  41 . Accordingly, chemical is introduced to create a high pressure solution maintained at, according to some embodiments, the full 2000 psi pressure, without significantly reducing solution pressure and velocity through the foam assembly nozzle  58 . It should be noted that according to some embodiments, chemical dosing pumps (not illustrated), a solenoid controlled gravity feed, or other type of method could be used to inject chemicals upstream of the high pressure pump  41 . 
       FIG. 3  illustrates an in-bay automatic wash system  10 , wherein a wash bay  32  houses an in-bay automatic carwashing machine  30  and an adjacent equipment room  29  housing the main electrical panel  37  and the off-board equipment, including, for example, the motor  40 , the pump  41  and storage drums  46  and  86 . In the embodiment illustrated in  FIG. 3 , the main electrical panel  37  includes the logic controller  33 , the VFD pump motor starter  39  and a VFD motor drive  38 , to, as discussed in greater detail below, drive the car washing machine  30  located in the wash bay  32 . In operation, an array of thru-beam sensors  36   a ,  36   b ,  37   a  and  37   b  at the front of the wash bay  32  detect the presence of a vehicle  31  in the wash bay  32 . Once the vehicle  31  is in place, the logic controller  33  carries out a sequence of preconfigured wash cycles, as discussed in greater detail below. 
     In operation, the first pass is generally a soil emulsifying detergent or “presoak” pass. During the presoak pass cycle, the logic controller  33  signals the VFD motor  39  to start motor  40 , which is drivingly connected to the high pressure pump  41 . Simultaneously, the logic controller  33  signals 3-way valve  51  to actuate, enabling the suction lines  52  and  54  to be in fluid communication causing the high pressure pump  41  to draw water from conditioned water supply  50  through line  53  and pressurize a water feed hose  48  to approximately 2000 psi. Simultaneously, the logic controller  33  signals high pressure valve  42  to open, allowing the high pressure water to travel downstream through a suitably sized eductor  44 . As the feed water passes through the eductor  44 , the pressure drops to approximately 800 psi thereby creating a vacuum in chemical feed line  45  to pull detergent from the bulk detergent drum  46 . Meanwhile, a flexible high pressure hose  55  directs the detergent solution from the off-board area (i.e., the equipment room  29 ) to the on-board machine  30  in the wash bay  32  and connecting to the presoak arch  56  for distribution about the surface of the vehicle  31 . The logic controller  33  signals VFD drive motor  38  to drive the on-board machine reciprocally over the vehicle  31  along support beam  57  while presoak is discharged out of foam nozzle expansion assemblies  58 , as discussed in greater detail below. 
     According to some embodiments, in one or two passes, the volumized detergent covers the vehicle  31  and the logic controller  33  switches to a high pressure rinse cycle to wash remaining soil and detergent off of the vehicle  31 . For the rinse pass, the logic controller  33  maintains the high pressure pump on and actuates the 3-way valve  51  so as to connect the pump intake to draw from the tank  50 , and actuate a high pressure water valve  43  so as to cause rinse water to exit from the machine  30 , flow onto a rinse arch  59 , and dispense through rinse nozzles  60  and onto the vehicle  31 . Similar to the presoak pass, the logic controller  33  will then signal the VFD drive motor  38  to cause the machine  30  to pass over the vehicle  31  while rinsing takes place. 
     Embodiments disclosed herein enable both high pressure presoak solution and high pressure rinsing take place with the same high pressure pump and an air compressor is not required for presoak foam. 
     It should be understood that in connection with in-bay automatics, the discussion herein includes simplified examples, and in some embodiments, there are many more potential foamed chemicals that may be applied to the vehicle during an entire wash, such as chemical tire application, clear coat conditioner, “rain-ex” final sealer, secondary multi-color, or multi-scented detergents, etc. Therefore, there may be a greater or fewer number of storage drums  46  and  86  with many different stored liquid chemicals and the detergent foaming and application system may be mimicked and scaled accordingly to accommodate other chemistry for other applications. 
     Referring now to  FIG. 4 , a sectional detail view of the eductor  74 ,  75  and the foaming assembly  58  is illustrated in the context of the two-stage eductor embodiment wherein the high pressure 2000 psi main supply  97  feeds a first high pressure eductor  74  or  75 . As previously discussed, the eductors  74 ,  75  are located off-board in a location, such as, for example, an adjacently positioned equipment room  29 . The eductors  74 ,  75  include a water inlet, an orifice  109  which controls and restricts the solution flow, a vacuum chamber  108 , which allows the drawing in of wash chemicals into solution through tube  107  and a Bernoulli effect acceleration chamber  110  creating the vacuum. After passing through the eductor  74 ,  75 , the water pressure drops, in accordance with one embodiment, by 60-70% to approximately 800 psi and moved through an extended length high pressure umbilical hose  96  and terminating into the foam generating nozzle assembly  58 , which lies in close proximity to the vehicle  31  to be washed. 
     With reference to  FIGS. 3 and 4 , the foaming assembly  58  includes an eductor  90  having a solution inlet with a reducing orifice  113  to control and restrict solution flow. The foam eductor  90  further includes a vacuum chamber  114  to allow ambient air to be pulled in, an air intake flow control  92  to control how much foaming aeration is pulled in, an air intake flow knob  111  control to manually control the aeration by increasing or decreasing the air passageway size, and a Bernoulli effect acceleration chamber  115  to create a vacuum to pull in the ambient air. According to some embodiments, the pressure at this point drops another 60-70% to (200-300 psi at the lower end of the scale) and is pushed through a foam generating screen  88  for optimal agitation. Thereafter, the foam exits the nozzle  77  and is directed onto the vehicle  31 . 
     This method of foam generation allows a much higher pressure, volume, and foam density without the use of an air compressor. Prior art methods utilize an air compressor and the exit foam pressure would not exceed more than 60 psi. In certain embodiments disclosed herein, the exit pressure will typically range from 180 to 750 psi depending on initial pump water pressure, although it should be understood that the range could be less than 180 psi or greater than 750 psi. 
     In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. 
     In the specification and claims, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear. 
     In addition, the foregoing describes only some embodiments of the invention(s), and alterations, modifications, additions and/or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive. 
     Furthermore, invention(s) have described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention(s), as defined solely by the appended claims. Also, the various embodiments described above may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments. Further, each independent feature or component of any given assembly may constitute an additional embodiment.