Patent Publication Number: US-2021169100-A1

Title: System and Method for Automatically Cleaning and Washing Ice Cream or Yogurt Machine

Description:
CROSS REFE 35 U.S.C. § 120 RENCE OF RELATED APPLICATION 
     This application is a Divisional application that claims the benefit of priority under 35 U.S.C. § 120 to a non-provisional application, application Ser. No. 15/431,773, filed Feb. 14, 2017 and another non-provisional application, application Ser. No. 15/455,153, filed Mar. 10, 2017, which is a Continuation-In-Part application that claims the benefit of priority under 35 U.S.C. § 120 to a non-provisional application, application Ser. No. 15/431,773, filed Feb. 14, 2017, which is a non-provisional application that claims the benefit of priority under 35 U.S.C. § 120 to a provisional application, application No. 62/345,765, filed Jun. 4, 2016, which are incorporated herewith by references in their entiirety. 
    
    
     NOTICE OF COPYRIGHT 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to any reproduction by anyone of the patent disclosure, as it appears in the United States Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. 
     BACKGROUND OF THE PRESENT INVENTION 
     Field of Invention 
     The present invention relates to ice cream and yogurt machine cleaning and washing, and more particularly to a system and method for cleaning and washing ice cream or yogurt machine automatically. 
     Description of Related Arts 
     Traditional ice cream and yogurt machines or makers are required to periodical wash and clean in order to prevent serious sanitary problems, such as bacterial growth and contamination, generated inside components of the ice cream machines or makers. Generally, due to the complicated structure of the ice cream or yogurt machine, it has to be cleaned and washed manually at least every two to three weeks. 
     A common cleaning method is the Pasteurization method that does not require to drain out the raw materials inside the direct expansion evaporator cylinder but simply heats the ice cream or yogurt making system, including the direct expansion evaporator cylinder, to a temperature such as 65° C. and keeps such temperature for around 30 minutes. Then, the ice cream or yogurt making system is cooled down to 5° C. in 30 minutes in order to kill the bacteria therein with hot ice cream or yogurt raw material. Each cleaning process must be operated around every 15 days. However, the Pasteurization method, in fact, is not a cleaning nor washing method because the direct expansion evaporator cylinder and the pipelines of the ice cream or yogurt machine have not been actually cleaned or washed but simply try to raise the temperature to kill the bacteria. Practically speaking, the ice cream or yogurt original contained in the ice cream or yogurt machine which had been heated to 65° C. are not suitable to consume and must be drained out to abandon and discard. In addition, this Pasteurization method is not suitable for yogurt because the probiotics in the yogurt will also be killed at the temperature of 65° C. 
     In order to really clean and wash the ice cream or yogurt machine, it must be disassembled so as to wash and clean the interior of the direct expansion evaporator, the dispenser mechanism and their pipelines manually. For example, in the traditional washing method, the raw materials inside the direct expansion evaporator cylinder is required to be drained out first, and then the cleaning water and detergents are injected into the pipelines of the ice cream machines or markers to drain out the residue inside the ice cream machines or markers. 
     However, the traditional cleaning and washing method for ice cream machines or markers have several drawbacks. 
     The dispensing components such as the plunger, the mix hopper, the draw spout, the draw handle, the sector gear, and etc., are required to be disassembled in order to reach the pipelines of flowing passages to clean such components and pipelines. In addition, each part of the components is required to be manually disassembled and reassembled by hand or accessories, so lots of labor and time have to spend during the traditional cleaning and washing method. In other words, since the ice cream or yogurt machine and marker are required to be cleaned and washed periodically, the components are easily to be damaged and broken during disassembling and reassembling. Furthermore, some components of the ice cream machine and marker cannot be cleaned and washed effectively, such as the freezing cylinders (direct expansion evaporator) and valves, so the cleaning and washing efficiency of the traditional washing and cleaning method is relatively low, and the components which cannot be fully cleaned or washed and are easily eroded, and in such a manner, not only that components needs to be repaired, but also that the finished ice cream will be contaminated. 
     SUMMARY OF THE PRESENT INVENTION 
     The invention is advantageous in that it provides a system and method for automatically cleaning and washing the ice cream or yogurt machine, wherein the components of the ice cream machines don&#39;t need to be disassembled during the cleaning operation in order to enhance the efficiency for cleaning and washing the ice cream or yogurt machine as well as prolong the life-span of the ice cream and yogurt machines. 
     Another advantage of the invention is to provides a system and method for automatically cleaning and washing the ice cream or yogurt machine, wherein not only the pipelines, including all flowing passages of the ice cream or yogurt, but also the interior of the freezing cylinder of the ice cream or yogurt machine can be washed and cleaned thoroughly, so as to enhance the efficiency for cleaning and washing the ice cream machines. 
     Another advantage of the invention is to provide a system and method for automatically cleaning and washing the ice cream or yogurt machine, wherein the system comprises a control panel to not only control an on/off operation but also a cleaning operation of the ice cream or yogurt machine automatically without any labor in looking after or disassembling any part or component thereof during the cleaning and washing process. 
     Another advantage of the invention is to provide a system and method for automatically cleaning and washing the ice cream machines, wherein the liquid raw material container can be selectively changed to the water tank or detergent tank during the cleaning and washing process, so as to simply the pipeline and structure of the ice cream or yogurt machine. 
     Another advantage of the invention is to provide a system and method for automatically cleaning and washing the ice cream machines, wherein the cleaning and washing method is a clean-in-place process that can thoroughly clean and wash all the flowing passages of the ice cream or yogurt, including the interior of the freezing cylinder and the pipelines of the ice cream or yogurt without moving or disassembling any component and connecting any additional equipment to the ice cream or yogurt machine. 
     Another advantage of the invention is to provide a system and method for automatically cleaning and washing the freezing cylinder of the ice cream or yogurt machine, wherein the refrigerant and the heat exchange channel therein of the freezing cylinder (direct expansion evaporator) which is thermally communicating with the feeding channel of the freezing cylinder with the refrigerant flowing therein for cooling the ice cream or yogurt raw material to frozen product are alternatively and selectively utilized to heat up the frozen ice cream or yogurt in the freezing cylinder for draining out and the cleaning liquid fed into the freezing cylinder for cleaning and washing after the raw material has been drained out. 
     Additional advantages and features of the invention will become apparent from the description which follows, and may be realized by means of the instrumentalities and combinations particular point out in the appended claims. 
     According to the present invention, the foregoing and other objects and advantages are attained by a system for automatically cleaning and washing an ice cream or yogurt machine, wherein the system comprises: 
     a liquid container for storing raw materials; 
     a freezing cylinder connected with the liquid container through a cleaning pathway; 
     a rinse containing device comprising at least a water tank for storing rinse water to rinse the freezing cylinder and cleaning pathway which may further comprise a detergent tank for storing one or more detergents to clean and wash the freezing cylinder and cleaning pathway; 
     a pump arranged on the cleaning pathway to selectively pump the raw material, the rinse water and/or the detergent; and 
     a control panel adapted to control an on/off and cleaning operation. 
     In accordance with another aspect of the invention, the present invention comprises a method for automatically cleaning and washing an ice cream or yogurt machine, wherein the method comprises the following steps: 
     (a) Stop feeding the raw materials to the freezing cylinder. 
     (b) Absorb the residues inside the freezing cylinder, and drain out the residues. 
     (c) Inject the rinse liquid including water and one or more detergents through the freezing cylinder and the pipeline. 
     (d) Inject rinse water through the freezing cylinder and the pipeline. 
     Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
     These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a method and system for automatically cleaning and washing ice cream machines according to a first preferred embodiment of the present invention. 
         FIG. 2  is a block diagram of a method and system for automatically cleaning and washing ice cream machines according to a second preferred embodiment of the present invention. 
         FIG. 3  is a schematic view illustrating an exemplary ice cream or yogurt machine. 
         FIG. 4  is a flow chart illustrating an exemplary pipeline of all flow passages of an ice cream or yogurt machine. 
         FIG. 5  is a perspective view of an ice cream or yogurt machine according to a third preferred embodiment of the present invention. 
         FIG. 6A  is a schematic view illustrating the liquid container receiving chamber of the ice cream or yogurt machine according to the above third preferred embodiment of the present invention. 
         FIG. 6B  is a schematic view illustrating an alternative mode of rinse liquid supply of the ice cream or yogurt machine according to the above third preferred embodiment of the present invention. 
         FIG. 6C  is a schematic view illustrating another alternative mode of rinse liquid supply of the ice cream or yogurt machine according to the above third preferred embodiment of the present invention. 
         FIG. 7  is a sectional view of a freezing cylinder according to the above third preferred embodiment of the present invention. 
         FIG. 8  is a block diagram illustrating the thermal exchange arrangement of the ice cream and yogurt machine according to the above third preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description is disclosed to enable any person skilled in the art to make and use the present invention. Preferred embodiments are provided in the following description only as examples and modifications will be apparent to those skilled in the art. The general principles defined in the following description would be applied to other embodiments, alternatives, modifications, equivalents, and applications without departing from the spirit and scope of the present invention. 
     Referring to  FIG. 1  of the drawings, a system for automatically cleaning and washing ice cream or yogurt machine according to a preferred embodiment of the present invention is illustrated, wherein the system comprises a liquid container  1  for storing raw materials for products such as ice cream, yogurt, beverages and the like in frozen manner, a freezing cylinder  2 , for example a direct expansion evaporator, connecting with the liquid container  1  and a dispensing device through a pipeline, adapted to make the ice cream or yogurts from the raw materials, a rinse containing device for storing a rinsing liquid, which may include a detergent tank  3  for storing one or more detergents and a water tank  4  for storing the rinse water, an air inlet  6  adapted to conduct outside air to the freezing cylinder, a pump  8  adapted to selectively pump the raw materials or the detergents and the rinse water into the freezing cylinder  2 , and a control panel  5  adapted to control an on/off and a cleaning operation of the ice cream or yogurt machine. In addition, the liquid container  1 , the freezing cylinder  2 , the detergent tank  3 , and the water tank  4  are connected with each other through a pipeline, wherein the pipeline comprises a duct  9 , a duct  10 , a duct  11 , and a duct  12  defining a cleaning pathway, wherein the raw materials stored inside the liquid container  1  is fed from the liquid container  1  to the freezing cylinder  2  through the duct  9 , and the ice cream or yogurt is made in the freezing cylinder  1  and dispensed through a dispensing system of the ice cream or yogurt machine. In some embodiments, the air can be conducted into the freezing cylinder  1  through the air inlet  6 , so the air is mixed with the raw materials inside the freezing cylinder  2  so as to produce the soft-serve products such as ice cream, yogurt, beverages and the like. 
     According to the first preferred embodiment, the one or more detergents can be fed from the detergent tank  3  to the freezing cylinder  2  through the duct  10  which is integrally connected with the duct  9 . The rinse water is fed from the water tank  4  to the freezing cylinder through the duct  11  which is integrally connected with the duct  10 . In other words, since the raw materials is fed through the duct  9  to the freezing cylinder  2 , the residue will be remained inside the duct  9  and the freezing cylinder  2 . 
     It is worth mentioning that the detergents may also be premixed with the water and contained in the detergent tank  3  and fed into the freezing cylinder  2  through the duct  10 . Also, the rinse water can be supplied from a water supply such as a water faucet connected to the duct  11  or the duct  10  via a three-way valve. 
     Generally, the raw materials for freezing into ice cream or yogurt are fed from the liquid container  1  to the freezing cylinder  2  through the duct  9  by the pump  8 , wherein the raw materials will be frozen by the freezing cylinder  2  and dispensed through the dispensing system, and the frozen ice cream or yogurt residues will be remained inside the duct  9  and freezing cylinder  2  even after the raw materials are drained out of the system. Therefore, the rinse water stored inside the rinse water tank  4  and the detergent stored inside the detergent tank  3  are fed through the duct  9  to the freezing cylinder  2  in order to efficiently clean the pipeline and the freezing cylinder  2  of the ice cream or yogurt machine. 
     The system according to the first preferred embodiment of the present invention further comprises a heating unit  7  operatively connected with the freezing cylinder  2  to heat the freezing cylinder  2 , wherein the heating unit  7  is adapted to absorb the ice cream residues remaining inside the freezing cylinder  2 , so as to facilitate the ice cream or yogurt residues being completely drained out from the freezing cylinder  2 . In addition, after the rinse water fed into the freezing cylinder  2 , the rinse water can also be heated by the heating unit  7  to clean and wash out all the ice cream or yogurt residues, and then the freezing cylinder  2  can be rinsed more efficiently by the heated rinse water. 
     According to the first preferred embodiment, the pump  8  is a peristaltic pump, wherein the pump  8  can be activated by the control panel  5  to pump the raw materials, the detergents, or the rinse water to the freezing cylinder  2 . The system further comprises a valve  13  arranged at the duct  9 , a valve  14  arranged at the duct  10 , and a valve  15  arranged at the duct  11 . Accordingly, while only the valve  13  is opened, only the raw materials stored in the liquid container  1  is fed to the freezing cylinder  2 . While only the valve  14  is opened, only the detergents are fed to the freezing cylinder  2 . While only the valve  15  is opened, only the rinse water is fed to the freezing cylinder  2 . 
     According to the first preferred embodiment, the control panel  5  comprises an on/off module and a cleaning operation module, wherein the on/off module can be activated to turn on and turn off the operation of the freezing cylinder  2 , and the cleaning operation module can be activated to turn on and turn off the cleaning operation. It is worth to mention that the cleaning operation module can be activated to turn on and turn off the cleaning operation by times or usage, that is to turn on and turn off the cleaning operation of the cleaning and washing system of the ice cream or yogurt machine automatically at predetermined or preset times, or to turn on and turn off the cleaning operation of the cleaning and washing system of the ice cream or yogurt machine manually according to the need of the user of the ice cream or yogurt machine. In other words, the cleaning operation can be set up to turn on/turn off by times, such as one week per time, three days per time, or daily, and in addition, the cleaning operation module also can be set up to turn on/turn off the cleaning operation by usage, such as that the cleaning operation module can be activated to turn on the cleaning operation while the raw materials stored inside the liquid container  1  are pumped to the freezing cylinder  2  by 100 loads. And, the control panel  5  further comprises a sensor connected to the freezing cylinder  2  to detect the usage loads of the liquid containers  1 . It is worth mentioning that the control panel  5  further comprises a valve module to control an on/off operation of each of the valve  13 , the valve  14 , and valve  15 . 
     Referring to  FIG. 2  of the drawings, a system of automatically cleaning and washing the ice cream or yogurt machine according to a second preferred embodiment of the present invention is illustrated, wherein the system comprises a liquid container  1 A for storing raw materials for the soft-serve products, such as ice cream, yogurt, beverages and etc., a freezing cylinder  2 A adapted to freeze the raw materials to make the frozen ice cream or yogurts, a rinse containing device which may comprises a detergent tank  3 A for storing one or more cleaning detergents and a water tank  4 A for storing the rinse water, an air inlet  6 A adapted to conduct outside air to the freezing cylinder  2 A, a pump  8 A adapted to pump the raw materials, the detergent, and the rinse water into the freezing cylinder  2 A, and a control panel  5 A adapted to control an on/off and a cleaning operation of the ice cream or yogurt machine, wherein the raw materials stored inside the liquid container  1 A is fed from the liquid container  1 A to the freezing cylinder  2 A through the duct  9 A, and the ice cream or yogurt is made in the freezing cylinder  2 A. In one embodiment, the air can be conducted into the freezing cylinder  2 A through the air inlet  6 A, so the air can be mixed with the raw materials inside the freezing cylinder  2 A so as to produce the ice cream or yogurt product. 
     The liquid container  1 A can be selectively replaced by rinse containing device, such as the water tank  4 A or detergent tank  3 A, in order to process the cleaning operation, wherein the liquid container  1 A, the water tank  4 A, and the detergent tank  3 A can be selectively connected to the duct  9 A to selectively pump the raw materials, the rinse water, or the detergents into the freezing cylinder  2 A. 
     The system according to the second preferred embodiment of the present invention may further comprise a heating unit  7 A operatively connected with the freezing cylinder  2 A to heat the freezing cylinder  2 A, wherein the heating unit  7 A is adapted to absorb the ice cream or yogurt residues remaining inside the freezing cylinder  2 A, so as to facilitate the ice cream or yogurt residues being drained out from the freezing cylinder  2 A. In addition, after the rinse water fed into the freezing cylinder  2 A, the rinse water can be selectively heated by the heating unit  7 A, and then the freezing cylinder  2 A can be rinsed by the rinse water or heated rinse water. 
     The system according to the second preferred embodiment of the present invention may further comprise a valve  13 A arranged at the duct  9 A. Accordingly, while the valve  13 A is opened, the raw materials stored inside the liquid container  1 A is fed to the freezing cylinder  2 A as long as the duct  9 A is connected to the liquid container  1 A. If the duct  9 A is connected to the detergent tank  3 A, the detergents are fed to the freezing cylinder  2 A. If the duct  9 A is connected to the water tank  3 A, the rinse water is fed to the freezing cylinder  2 A. 
     According to the second preferred embodiment, the control panel  5 A comprises an on/off module and a cleaning operation module, wherein the on/off module can be activated to turn on and turn off the operation of the freezing cylinder  2 A, and the cleaning operation module can be activated to turn on and turn off the cleaning operation. It is worth mentioning that the cleaning operation module can be activated to turn on and turn off by times or usage, wherein the cleaning operation can be set up to turn on/turn off automatically according to predetermined or preset times, such as one week per time, three days per time, or daily after the business hours, and the cleaning operation module also can be set up to turn on/turn off by usage, that is being manually activated by the user according to his or her actually need. For example, the cleaning operation module can be activated to turn on the cleaning operation while the raw materials stored inside the liquid container  1 A are pumped to the freezing cylinder  2 A by 100 loads. And, the control panel  5 A may further comprise a sensor connected to the liquid container  1 A to detect the usage loads of the liquid containers  1 A. It is worth to mention that the control panel  5 A further comprises a valve module to control an on/off operation of the valve  13 A. 
     According to the above preferred embodiments, it is worth mentioning that the system for cleaning and washing the ice cream or yogurt machine includes mostly the components of the ice cream or yogurt machine, such as the liquid container  1 ,  1 A, the freezing cylinder  2 ,  2 A, the pump  8 ,  8 A, and the control panel  8 ,  8 A. In order to convert an ice cream or yogurt machine to equip with the system for cleaning and washing the ice cream or yogurt machine, the machine may simply be modified to provide the ducts  9 ,  10 ,  11 ,  12 , the rinse containing device including the water and detergent tanks  3 ,  3 A,  4 ,  4 A, and the valves  13 ,  14 ,  15 , and to modified the control panel  5 ,  5 A to provide the on/off module and cleaning operation module. 
     According to the above first and second preferred embodiments, a method for automatically cleaning and washing the ice cream or yogurt machine is provided, wherein the method comprises the steps of: 
     (a) stopping feeding the raw materials to the freezing cylinder  2 ,  2 A; 
     (b) absorbing the ice cream or yogurt residue inside the freezing cylinder  2 ,  2 A, and draining out the residue; 
     (c) injecting the water through the freezing cylinder  2 ,  2 A and the pipeline; and/or 
     (d) injecting the one or more detergents or detergents mixed with water through the freezing cylinder  2 ,  2 A and the pipeline; and 
     (e) finally, injecting the rinse water through the freezing cylinder  2 ,  2 A and the pipeline. 
     In the step (a), the pump  8 ,  8 A is activated to be turned off by the control panel  5 ,  5 A, so that no raw material is fed into the freezing cylinder  2 ,  2 A. Alternatively, the valve  13  can be turned off by the control panel  5 ,  5 A, no raw material is fed into the freezing cylinder  2 ,  2 A. It is worth to mention that, in the second preferred embodiment, the liquid container,  1 A can be selectively replaced by the rinse containing device, including the water tank  4 A and/or the detergent tank  3 A, so that while the valve  13 A is opened, the raw materials, the rinse water, or the detergents can be selectively fed into the freezing cylinder  2 A through the duct  9 A. 
     In the step (b), the freezing cylinder  2 , 2 A is heated by the heating unit  7 ,  7 A, and the ice cream or yogurt residue is dissolved and absorbed by the heated water or water mixed with detergents and then drained out from the freezing cylinder  2 ,  2 A. 
     In the step (c), in the first preferred embodiment, the valve  13  and the valve  14  are closed, the valve  15  is turned on, and the pump is turned on, so that the rinse water can be fed through the pipeline and the freezing cylinder  2 , so as to clean and wash the pipeline and the freezing cylinder  2 . 
     Accordingly, the step (c) further comprises a step of (c 1 ): heating the rinse water, wherein the heated rinse water is passing through the pipeline and the freezing cylinder  2 ,  2 A, so as to wash and clean the pipeline and the freezing cylinder  2 ,  2 A. In other words, the heated rinse water has a better washing efficiency than the regular temperature rinse water. 
     In the step (d), in the first preferred embodiment, the valve  13  is closed, the valve  14  is turned on, and the pump  8  is turned on, so that the one or more detergents can be fed through the pipeline and the freezing cylinder  2 , so as to clean and wash the pipeline and the freezing cylinder  2 . 
     In the step (e), the detergent residue can be cleaned and drained out by the rinse water. In other words, the one or more detergents are usually chemicals, so it may cause harmful for the human body. Therefore, the step (e) can prevent the detergents remained inside the pipeline and the freezing cylinder  2 ,  2 A. Of course, if the detergents are made of edible elements, the step (e) may also be omitted. 
     Referring to  FIGS. 5 to 8 , a system for automatically cleaning and washing an ice cream or yogurt machine according to a third preferred embodiment is illustrated. The system for cleaning and washing an ice cream or yogurt machine according to the third preferred embodiment of the present invention can be applied to the ice cream or yogurt machine as shown in  FIGS. 5-8  or any conventional ice cream or yogurt machine as shown in  FIG. 3 , which illustrates a block diagram of a conventional ice cream or yogurt machine  10 ′ such as the U.S. Pat. No. 6,145,701 as an example, wherein an ice cream or yogurt machine comprises a liquid container  1 ′, a freezing cylinder  2 ′, a mix hopper  14 ′ for containing soft-serve material mixed by one or more raw materials stored in the liquid container  1 ′ and being in flow communication with the freezing cylinder  2 ′, a pipeline  3 ′ connecting the liquid container  1 ′ and the mix hopper  14 ′ to the freezing cylinder  2 ′ and the freezing cylinder  2 ′ to a draw spout device  41 ′ of a dispensing device  4 ′ via a plunger  42 ′ thereof, and a beater assembly  21 ′ installed within the freezing cylinder  2 ′ for expelling frozen soft-serve product such as ice cream or yogurt from the freezing cylinder  2 ′ via the pipeline  3 ′ to the draw spout  41 ′. As shown in  FIG. 4 , a pipeline of all flow passages such as U.S. Pat. No. 8,335,587 is illustrated as an example, wherein a pump  8 ′ is provided to pump the raw materials though the freezing cylinder  2 ′ and the pipeline  3 ′ to produce frozen soft-serve product such as ice cream or yogurt to be dispensed at the draw spout  41 ′ of the dispensing device  4 ′, as illustrated in  FIG. 6C . 
     The freezing cylinder  2 ′ can be the conventional freezer barrel as illustrated in the U.S. Pat. No. 6,145,701 and U.S. Pat. No. 8,335,587 patents or an improved direct expansion evaporator as disclosed in the U.S. Pat. No. 8,272,231 and U.S. Pat. No. 8,534,086 invented by the inventor of this application, as shown in  FIG. 7 , wherein the freezing cylinder (direct expansion evaporator)  2 ′ comprises a feeding channel  10 A′ and a heat exchange channel  20 A thermally communicating with the feeding channel  10 A′ for heat exchanging. 
     The feeding channel  10 A′ has a feeding end  12 A′ and an opposite dispensing end  14 A for the one or more raw materials of ice cream or yogurt feeding through the feeding channel  10 A from the feeding end  12 A′ to the dispensing end  14 A′. An air inlet  16 A′ is also formed at the feeding end  12 A′ of the feeding channel  10 A′ to enable air and the one or more raw materials being mixed together before the mixed one or more raw materials are heat-exchanged with the refrigerant  60 A′. 
     The heat exchange channel  20 A′ has an inlet  22 A′ and an outlet  24 A′ preferably for the refrigerant  60 A′ flowing through the heat exchange channel  20 A′, wherein the feeding channel  10 A′ is coaxially aligned with the heat exchange channel  20 A′. Accordingly, the refrigerant  60 A′ is guided to pass through the heat exchange channel  20 A′ from the inlet  22 A′ to the outlet  24 A′ for heat exchanging with the raw material within the feeding channel  10 A′. Therefore, the one or more raw materials are guided to enter into the feeding end  12 A′ of the feeding channel  10 A′ while the frozen soft-sever product, i.e. ice cream or yogurt, is guided to exit the dispensing end  14 A′ of the feeding channel  10 A′. 
     The inlet  22 A′ of the heat exchange channel  20 A′ is preferably located adjacent to the dispensing end  14 A′ of the feeding channel  10 A′, while the outlet  24 A′ of the heat exchange channel  20 A′ is located adjacent to the feeding end  12 A′ of the feeding channel  10 A′. Therefore, a flow direction of the refrigerant  60 A′ flowing from the inlet  22 A′ to the outlet  24 A′ of the heat exchange channel  20 A′ is concurrent and opposite to a feeding direction of raw material feeding from the feeding end  12 A′ to the dispensing end  14 A′ of the feeding channel  10 A′, so as to efficiently freezing the raw material to the frozen product. Alternatively, the flowing direction of the refrigerant  60 A′ and the feeding direction of the raw material may be in the same direction depending on the design and purpose of the direct expansion evaporator. However, the opposite direction between the refrigerant  60 A′ and the one or more raw materials as the preferred embodiment will enhance the energy efficiency of the heat exchange process. 
     It is worth mentioning that, the heat exchange channel  20 A′ and the feeding channel  10 A′ may be formed in variety of shapes for the refrigerant  60 A′ and the one or more raw materials passing therewithin respectively. The heat exchange channel  20 A′ may thermally communicate with the feeding channel  10 A′ for heat exchanging with the raw material in a plurality of configurations to achieve the heat transport between one medium, embodied as refrigerant, to another medium, embodied as raw material for making frozen product. 
     In particular, the traveling path of the heat exchange channel  20 A′, i.e. the helix distance between the inlet  22 A′ and the outlet  24 A′ of the heat exchange channel  20 A′, is long enough for phase-changing the refrigerant  60 A′ that the refrigerant  60 A′ is in liquid phase under a predetermined high pressure when entering into the heat exchanging channel  20 A′ and is in gaseous phase when exiting the heat exchanging channel  20 A′. 
     Accordingly, the thermal energy, which is needed for making the frozen soft-serve product, is preferably through the phase change between the liquid phase and the gaseous of the refrigerant  60 A′. The refrigerant  60 A′ is preferably in liquid phase under a predetermined high pressure when entering into the heat exchange channel  20 A′ through the inlet  22 A′. The liquid phase refrigerant  60 A′ is rapidly converting into gaseous phase after the refrigerant  60 A′ entering the heat exchange channel  20 A′ due to an expansion of area within the heat exchange channel  20 A′ and a pressure drop to decrease the boiling point of the refrigerant  60 A′. In addition, the thermal energy is exchanged between the refrigerant  60 A′ and the raw material. Therefore, a negative thermal energy is released via the absorption of the phase change of the refrigerant  60 A′ from liquid to gaseous state. Thus, the refrigerant  60 A′ is able to be evaporated to gaseous phase in an expansion manner, so as to prevent a back flow of the liquid refrigerant  60 A′ and to maximize the cooling capacity. 
     In other words, the liquid refrigerant  60 A′ is in gaseous phase exiting the heat exchange channel  20 A′ through the outlet  24 A′, such that the thermal energy can be totally release from the phase change of liquid refrigerant  60 A′ to gaseous state. For example, the refrigerant  60 A′ may be stored in a high pressure container in liquid state. The liquid refrigerant  60 A′ may be entered into the heat exchange channel  20 A′ in a pressurized manner, so that the liquid refrigerant  60 A′ is rapidly evaporated in the relatively lower pressure and larger space of heat exchange channel  20 A′. The conversion of the liquid phase to gaseous phase is an absorption reaction, so that the refrigerant  60 A′ absorbs a significant amount of heat from the raw material in the feeding channel  10 A′, so as to release negative thermal energy for making the frozen product. 
     In order to form the heat exchange channel  20 A′ from the outer guiding duct  30 A′, the outer guiding duct  30 A′ is pressed by machine at the outer surrounding wall of the outer guiding duct  30 A′. Accordingly, a helix indention  50 A′ is formed at the outer guiding duct  30 A′ to form the heat exchange channel  20 A′ partitioned by a helix partition  51 A′, wherein a peak  511 A′ of the helix partition  51 A′ is biased against the outer surrounding wall of the inner guiding duct  32 A′ to conceal the heat exchange channel  20 A′ along the inner guiding duct  32 A′ in a weld-less manner. 
     It is worth mentioning that the above description of the conventional ice cream or yogurt machines and freezing cylinder is merely for facilitating the illustration of features of the present invention but not intending to form any limitation to the scope of the present invention. 
     According to the third preferred embodiment of the present invention, it is appreciated that the system for cleaning and washing ice cream or yogurt machine includes existing components of the machine without the need to install additional expensive or complicated devices or to have too much modification in structure to the machine. It is not only to be applied in the new made machine but also convenient in modifying any existing machine to perform the automatic cleaning and washing function for the machine. 
     According to the above preferred embodiments, the system for cleaning and washing the ice cream or yogurt machine includes components of the machine, including at least the freezing cylinder  2 ′ for freezing the raw materials feeding from the liquid container  1 ′ to produce the frozen soft-serve product such as ice cream or yogurt, the pipeline  3 ′ connecting the liquid container  1 ′ with the freezing cylinder  2 ′ and the freezing cylinder  2 ′ to the dispensing device  4 ′, the pump  8 ′ adapted for pumping the one or more raw materials from the liquid container  1 ′ to the freezing cylinder  2 ′ and the frozen soft-serve product from the freezing cylinder  2 ′ to the dispensing device  4 ′ via the pipeline  3 ′ which comprises a feeding pipeline  31 ′ connecting the liquid container  1 ′ with the freezing cylinder  2 ′ and a dispensing pipeline  32 ′ connecting the freezing cylinder  2 ′ with the dispensing device  4 ′, and a control module  5 ′ adapted for controlling the operation of the feeding of the raw materials from the liquid container  1 ′ to the freezing cylinder  2 ′ by the pump  8 ′, the operation of the heat exchange of the freezing cylinder  2 ′, the operation of the dispensing of the frozen soft-serve product from the freezing cylinder  2 ′ to the dispensing device  4 ′, and the dispensing operation of the dispensing device  4 ′. The control module  5 ′ is modified from the control panel of the general ice cream or yogurt machine that not only executes and controls the operation of the freezing cylinder  2 ′ to make ice cream or yogurt and the dispensing of the ice cream or yogurt soft-serve product through the dispensing device  4 ′, but also further includes an on/off module  51 ′ and a cleaning operation module  52 ′, wherein the on/off module  51 ′ controls the cleaning and washing time and activates the cleaning operation module  52 ′ to control the unfrozen and draining out of the remaining raw material and ice cream or yogurt in the freezing cylinder  2 ′ and pipeline  3 ′ as well as the feeding of the detergents and water for cleaning and washing of the freezing cylinder  2 ′ and pipeline  3 ′. 
     In order to provide the automatic cleaning and washing system for the ice cream or yogurt machine as described above, the system further comprises a rinse liquid supply  10 ′ for supplying rinsing liquid which is embodied as a rinse containing device  11 ′ in the third preferred embodiment for replacing the liquid container  1 ′ in the liquid container receiving chamber  100 ′ during the cleaning and washing operation, as shown in  FIG. 6A . The rinse containing device  11 ′ comprises a detergent tank  111 ′ for storing one or more detergents, preferable edible detergents, and a water tank  112 ′ for storing rinse water, wherein the inlet terminal  311 ′ of the feeding pipeline  31 ′ of the pipeline  3 ′ which is originally placed in the liquid container  1 ′ for pumping raw materials in the liquid container  1 ′ to the freezing cylinder  2 ′ is also moved to place in the detergent tank  111 ′ or the water tank  112 ′ of the rinse containing device  11 ′. It is worth mentioning that the detergent tank  111 ′ and the water tank  112 ′ can be the same tank body that when the one or more detergents are stored therein, it is functioning as the detergent tank  111 ′ and, when the rinse water is stored therein, it is functioning as the water tank  112 ′. 
     Alternatively, the rinse liquid supply  10 ′ may also comprises a rinse containing device  11 ′ and a water supply  12 ′, wherein the rinse containing device  11 ′ merely comprises a detergent tank  111 ′ which can be selectively installed in the ice cream or yogurt machine to replace the liquid container  1 ′ during the cleaning and washing time so that no extra space is required to place the detergent tank  111 ′, as shown in  FIG. 6B . Or, alternatively, when a new ice cream and yogurt machine is made, additional space can also be designed to install the rinse containing device  11 ′, as shown in  FIG. 6C , wherein a second inlet terminal  312 ′ of the feeding pipeline  31 ′ of the pipeline  3 ′ is connected therein where a feeding three-way valve  313 ′ is installed between the inlet terminal  312 ′ and the second inlet terminal  312 ′ of the feeding pipeline  31 ′ for selectively switching the feeding of the raw materials in the liquid container  1 ′ or the detergents in the detergent tank  111 ′ into the feeding pipeline  31 ′ by the cleaning operation module  52 ′ of control module  5 ′. The water supply  12 ′ comprises a water supply pipeline  121 ′ having one end connected to a water source such as a water faucet and another end connected to the feeding pipeline  31 ′ if the pipeline  3 ′ via a three-way valve  313 ′ which is controlled by the cleaning operation module  52 ′ of the control module  5 ′. 
     Referring to  FIG. 8 , a thermal exchange arrangement  20 ′ of the ice cream or yogurt machine according to the third preferred embodiment of the present invention is illustrated, wherein the thermal exchange arrangement  20 ′ comprises the freezing cylinder  2 ′, such as the direct expansion evaporator  2 A′ as disclosed above as an example, a thermal exchange device  21 ′, such as a condenser, having a first outlet  211 ′ connecting to the inlet  22 A′ of the direct expansion evaporator  2 A′ (freezing cylinder  2 ′) with a first refrigerant duct  201 ′ for feeding cold liquid refrigerant  60 A′ into the exchange channel  20 A′ of the freezing cylinder  2 ′ (direct expansion evaporator  2 A′), and a compressor  22 ′ connecting to the thermal exchange device  21 ′ with a compressor duct  202 ′ for compressing refrigerant to feed in the thermal exchange device  21 ′ and to the outlet  24 A′ of the direct expansion evaporator  2 A′ (freezing cylinder  2 ′) with a second refrigerant duct  203 ′ for receiving gaseous refrigerant from the outlet  24 A′ and delivering back to the compressor  22 ′. According to the third preferred embodiment of the present invention, the thermal exchange arrangement  20 ′ further comprises a third refrigerant duct  204 ′ having one end connected to the thermal exchange device  21 ′ to collect heated refrigerant and another end connected the inlet  22 A′ of the direct expansion evaporator  2 A′ (freezing cylinder  2 ′), wherein the compressor  22 ′ and the three-way valve  23 ′ are controlled by the cleaning operation module  52 ′ of the control module  5 ′. 
     According to the third preferred embodiment of the present invention, the heating unit  7 ,  7 A as described in the above first and second preferred embodiments is embodied as the thermal exchange arrangement  20 ′ to produce heat to melt and dissolve the frozen ice cream or yogurt residue in the freezing cylinder  2 ′ and pipeline  3 ′ and be absorbed by the detergents and/or rinse water to enhance the cleaning and washing ability to the freezing cylinder  2 ′ and the pipeline  3 ′. This is accomplished by the thermal exchange device  21 ′ of the thermal exchange arrangement  20 ′. The thermal exchange device  21 ′ substantially conducts thermal exchange to produce cold air and hot air at the same time. When the thermal exchange device  21 ′ is functioned for refrigeration and used to condense gaseous form refrigerant from the outlet  24 A′ to liquid form refrigerant for feeding to the inlet  22 A′ of the exchange channel  20 A′ of the freezing cylinder  2 ′ during the normal operation of producing soft-serve ice cream or yogurt product by the freezing cylinder  2 ′. However, when the cleaning and washing operation of the machine is activated by the on/off module  51 ′ of the control module  5 ′, the cleaning operation module  52 ′ of the control module  5 ′ activates the thermal exchange device  21 ′ to function in a reverse way as a heater (functioned as the heating unit  7 ,  7 A as described in the above first and second embodiments) to product heat and the inlet  22 A′ of the freezing cylinder  2 ′ is switched to connect to the third refrigerant duct  204 ′ so that the heated refrigerant produced by the heat transfer of the thermal exchange device  21 ′ is fed into the exchange channel  20 A′ of the freezing cylinder  2 ′ to heat up the raw materials, the frozen ice cream or yogurt residue, the detergents, and/or the rinse water in the freezing cylinder  2 ′. 
     If the detergent tank  111 ′ is used to replace the liquid container  1 ′, after the business hours, firstly, stop feeding raw materials into the freezing cylinder  2 ′ and, when the scheduled cleaning and washing operation time starts, the remaining raw materials or frozen ice cream or yogurt soft-serve product contained in the freezing cylinder  2 ′ are drained out via the dispensing pipeline  32 ′ and dispensing device  4 ′ automatically or manually, and then the liquid container  1 ′ is replaced with the detergent tank  111 ′ of the rinse containing device  11 ′ and the inlet terminal  311 ′ of the feeding pipeline  31 ′ of the pipeline  3 ′ of the machine is placed into the detergents in the detergent tank  111 ′. Then, when the preset automatic cleaning and washing predetermined time starts, the thermal exchange device  21 ′ is activated to reversely function as the heating unit to circle heated refrigerant to the exchange channel  20 A′ of the freezing cylinder  2 ′ to warm up and melt the residues of the raw materials and/or frozen ice cream or yogurt in the feeding channel  10 A′ of the freezing cylinder  2 ′ for ease of cleaning out, and then the one or more detergents contained in the detergent tank  111 ′ which may further be mixed with water for desired concentration are pumped into the feeding pipeline  31 ′, fed into and through the feeding channel  10 A′ of the freezing cylinder (direct expansion evaporator)  2 ′ to wash out the residues of the dissolved raw materials and ice cream or yogurt in the freezing cylinder  2 ′, and dispensed through the dispensing pipeline  32 ′ and the dispensing device  4 ′, wherein the thermal exchange device  21 ′ may continuously be operated as the heating unit to circle heated refrigerant to the exchange channel  20 A′ of the freezing cylinder  2 ′ to warm up and dissolve the detergents and rinse water to facilitate the cleaning and washing the feeding channel  10 A′ of the freezing cylinder  2 ′. 
     If the additional detergent tank, which is either installed in the machine or outside the machine, is arranged, after the business hours, stop feeding raw materials into the freezing cylinder  2 ′ and, when the scheduled cleaning and washing operation time starts, the remaining raw materials and ice cream or yogurt contained in the freezing cylinder  2 ′ are drained out via the dispensing pipeline  32 ′ and dispensing device  4 ′ automatically or manually, wherein the draining out of the raw materials or unfrozen ice cream or yogurt soft-serve product contained in the freezing cylinder  2 ′ may also set to be processed automatically by the the/off module  51 ′ of the control module  5 ′ when the preset automatic cleaning and washing predetermined time starts. Then, the thermal exchange device  21 ′ is activated to reversely function as the heating unit to circle heated refrigerant to the exchange channel  20 A′ of the freezing cylinder  2 ′ to warm up and dissolve the residues of the raw materials and/or frozen ice cream or yogurt in the feeding channel  10 A′ of the freezing cylinder  2 ′ for ease of cleaning out, and then the one or more detergents contained in the detergent tank  111 ′ which may further be mixed with water for desired concentration are pumped into the feeding pipeline  31 ′, fed into and through the feeding channel  10 A′ of the freezing cylinder (direct expansion evaporator)  2 ′ to wash out the residues of the dissolved raw materials and ice cream or yogurt in the freezing cylinder  2 ′, and dispensed through the dispensing pipeline  32 ′ and the dispensing device  4 ′, wherein the thermal exchange device  21 ′ may continuously be operated as the heating unit to circle heated refrigerant to the exchange channel  20 A′ of the freezing cylinder  2 ′ to warm up and dissolve the detergents and rinse water to facilitate the cleaning and washing the feeding channel  10 A′ of the freezing cylinder  2 ′. 
     According to the third preferred embodiment of the present invention, it does not require to disassemble any component of the ice cream or yogurt machine but simply preset the cleaning and washing time to a predetermined operation time, generally after business hours even every day and the machine will execute the cleaning and washing operation of the freezing cylinder  2 ′ and the pipeline  3 ′ automatically without any manual monitoring or operation. 
     Accordingly, the present invention provides a method of automatically cleaning and washing the ice cream or yogurt machine according to the above preferred embodiments, which comprises the following steps: 
     (A) Record a preset of a predetermined automatic cleaning and washing operation time in the on/off module  51 ′ of the control module  5 ′ and activating the cleaning operation module to process when the preset operation time starts. 
     (B) Stop the feeding of the one or more raw materials into the freezing cylinder  2 ′. 
     (C) Drain out the remaining raw materials and/or soft-serve product, such as ice cream or yogurt, from the freezing cylinder  2 ′ via the dispensing pipeline  32 ′ and the dispensing device  4 ′. 
     (D) Heat to melt the frozen residues of the raw materials and ice cream or yogurt in the freezing cylinder  2 ′ and drain out the unfrozen residues of the raw materials and ice cream or yogurt in the freezing cylinder  2 ′ and pipeline  3 ′ through the dispensing pipeline and the dispensing device. 
     (E) Feed the one or more detergents which may be mixed with water to reach a desired concentration through the feeding channel  10 A′ of the freezing cylinder  2 ′ and pipeline  3 ′, until the feeding channel  10 A′ inside the freezing cylinder  2 ′ and the pipeline  3 ′ are cleaned and washed out all residues of the raw materials and ice cream or yogurt. 
     (F) Feed rinse water through the feeding channel  10 A′ of the freezing cylinder  2 ′ and pipeline  3 ′ until they are cleaned and washed. 
     The step (E) further comprises the step of heating detergents by the heating unit (thermal exchange arrangement) in the freezing cylinder  2 ′. 
     The step (F) further comprises the step of heating the rinse water periodically by the heating unit (thermal exchange arrangement) in the freezing cylinder  2 ′. In other words, the rinse water fed to clean and wash the feeding channel  10 A′ of the freezing cylinder  2 ′ and the pipeline  3 ′ is selectively heated for a predetermined of time and then is not heated and remained in room temperature or cold in alternation for couple times. 
     The above steps (A) to (F) are executed automatically upon the control of the control module  5 ′ without labor and manual monitoring or operation. 
     The step (D) further comprises the steps of: 
     (D 1 ) switching the refrigeration function of the thermal exchange arrangement  20 ′ to heating function; and 
     (D 2 ) feeding the heating refrigerant into the exchange channel  20 A′ of the freezing cylinder  2 ′ to heat the feeding channel  10 A′ of the freezing cylinder  2 ′. This heating step (D 2 ) is continuously or selectively executed and controlled by the cleaning operation module  52 ′ of the control module  5 ′ during the step (E) and step (F) to heat the feeding channel  10 A′ of the freezing cylinder  2 ′ so as to heat up detergents and rinse water feeding therethrough to enhance the cleaning and washing ability of the detergents and rinse water. 
     One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
     It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.