Abstract:
Fluid is circulated through a heat exchange system for heat exchange to occur at a bundle of tubes making up a portion of the heat exchange system. Heat exchange efficiency at the bundle of tubes requires debris and fouling deposits accumulated therewithin to be substantially removed. Taking the heat exchange system off-line for physical flushing is not only ineffective but also disallow use of the heat exchange system for the duration it remains off-line. Described herein is an embodiment of a cleaning system which uses a displacement system for displacing cleaning balls carried in fluid into the bundle of tubes for cleaning thereof. A flow diverting system is configured and operable for introducing the cleaning balls to the bundle of tubes when in a first operating mode and for retrieving the cleaning balls from the plurality of tubes when in a second operating mode.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates generally to a cleaning system for use with heat exchangers for cleaning thereof. 
       BACKGROUND 
       [0002]    Heat exchange systems are used in various industries for a myriad of applications. Common applications of the heat exchange systems include heating ventilation and air-conditioning (HVAC) installations. In such installations, fluid is circulated through the heat exchange system for heat exchange to occur at a bundle of tubes making up a portion of the heat exchange system. Heat exchange efficiency at the bundle of tubes requires debris and fouling deposits accumulated therewithin to be substantially removed. Taking the heat exchange system off-line for physical flushing is not only ineffective but also disallow use of the heat exchange system for the duration it remains off-line. 
         [0003]    Cleaning systems for use in conjunction with the heat exchange systems uses elastomeric balls transported by fluid to be fed and circulated in the heat exchange system. When the elastomeric balls passage through the bundle of tubes during circulation in the heat exchange system, any debris or fouling deposits in the bundle of tubes are pushed out. The elastomeric balls are then subsequently retrieved by the cleaning system. 
         [0004]    However, it is known in the art that such cleaning systems utilises complex mechanisms for introducing the elastomeric balls into the heat exchange system and for the subsequent retrieval of the elastomeric balls therefrom. The complex mechanisms require frequent maintenance and proper coordination between mechanisms during use. Additionally, the configurations of existent cleaning systems known in the art are complicated and require extensive modifications to the heat exchange system in order for the cleaning system to be incorporated for use with the corresponding heat exchange system. 
         [0005]    Therefore, there is an apparent need for an improved cleaning system for addressing the foregoing problems. 
       SUMMARY 
       [0006]    In accordance with an aspect of the invention, there is disclosed a cleaning system for use with a plurality of tubes of a heat exchange system. The heat exchange system has an intake and an exhaust and comprises a displacement system, a manifold and a flow diverting system. The displacement system has a first port and a second port with the displacement system being operable for drawing liquid into the second port and expelling the drawn liquid out of the first port when in a first operating mode and drawing liquid into the first port and expelling the drawn liquid out of the second port when in a second operating mode. The manifold defines a first chamber and a second chamber with the manifold comprising a separator disposed between the first chamber and the second chamber. The first chamber is for receiving at least one cleaning ball. The separator defines at least one aperture for fluid communicating the first chamber with the second chamber and is shaped and dimensioned for substantially impeding passage of the at least one cleaning ball therethrough. The flow diverting system is adapted for fluid communicating the first port of the displacement system and the intake to the first chamber of the manifold and substantially impeding fluid communication of the first port and the exhaust with the second chamber and first chamber respectively when in the first operating mode. The flow diverting system is further adapted for fluid communicating the first port and the exhaust to the second chamber and first chamber respectively and substantially impeding fluid communication of each of the first port of the displacement system and the intake with the first chamber of the manifold when in the second operating mode. The at least one cleaning ball is displaced from the first chamber to the intake of the cleaning system for passage through the plurality of tubes when in the first operating mode and the at least one cleaning ball being drawn from the exhaust of the cleaning system into the first chamber when in the second operating mode. The at least one cleaning ball passages through the plurality of tubes for cleaning thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  shows a system flow diagram of a cleaning system coupled to a heat exchange system according to an embodiment of the invention; 
           [0008]      FIG. 2  shows a system flow diagram of the cleaning system of  FIG. 1  in a single pump configuration and operating in a first operating mode; 
           [0009]      FIG. 3  shows a system flow diagram of the cleaning system of  FIG. 1  in a single pump configuration and operating in a second operating mode; 
           [0010]      FIG. 4  shows a system flow diagram of the cleaning system of  FIG. 1  in a multi-pump configuration and operating in a first operating mode; and 
           [0011]      FIG. 5  shows a system flow diagram of the cleaning system of  FIG. 1  in a multi-pump configuration and operating in a second operating mode. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Reference will now be made in detail to an exemplary embodiment of the present invention, examples, of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the embodiment, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of embodiments of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the embodiments of the present invention 
         [0013]    For purposes of brevity and clarity, descriptions of embodiments of the present invention are limited hereinafter to cleaning systems for use with heat exchange systems. This however does not preclude embodiments of the invention where fundamental principals prevalent among the various embodiments of the invention such as operational, functional or performance characteristics are required. 
         [0014]    An exemplary embodiment of the invention, a cleaning system  20 , is described with reference to  FIGS. 1 to 5 . The cleaning system  20  is preferably used for cleaning a plurality of tubes  22  of a heat exchange system  24 . The plurality of tubes  22  is, for example, an evaporator or a condenser of heating, ventilation and air-conditioning (HVAC) systems or the like-heat-exchange systems. For such heat exchange systems, heat transfer occurs, at one or more segments containing the plurality of tubes  22 . Theses plurality of tubes  22  are typically clustered as a module with an intake  26  wherethrough liquid is introduced, and an exhaust  28  wherefrom liquid passaging through the plurality of tubes  22  are subsequently discharged. 
         [0015]    Preferably, a displacement pump (not shown) for circulating liquid, including when in the gaseous state, through the heat exchange system  24 , specifically through the plurality of tubes  22 . The cleaning system  20  is used in conjunction with the heat exchange system  24  by being integrated therewith fixably as an integrated component of the heat exchange system  24  or detachably to enable detachment of the cleaning system  20  from the heat exchange system  24  when not in use. 
         [0016]    The cleaning system  20  comprises a displacement system  30  having a first port  32  and a second port  34 , a manifold  36  and a flow diverting system  38 . Preferably, the cleaning system  20  comprises a first operating mode and a second operating mode. The flow diverting system  38  couples the manifold  36  to the intake  26  and the exhaust  28  of the plurality of tubes  22 . The displacement system  30  is operable for displacing liquid from the heat exchange system  24  through the manifold  36 . Preferably, a plurality of cleaning balls (not shown) are contained in the manifold  36 . The cleaning balls are preferably elastomeric balls. However, the cleaning balls may be made of other types of elastic materials. When in the first operating mode, flow of liquid displaced by the displacement system  30  is diverted to transport the plurality of cleaning balls out of the manifold  36  and into the intake  26  of the plurality of tubes  22 . As flow of liquid through the plurality of tubes  22  is from the intake  26  towards the exhaust  28 , the plurality of cleaning balls introduced into the intake  26  travels through the plurality of tubes  22  for cleaning thereof. The cleaning balls are preferably dimensioned to be smaller than the internal diameter of the plurality of tubes  22 . The cleaning balls are preferably shaped for ricocheting off the internal surface of the plurality of tubes while passaging therethrough for dislodging of debris and deposit therefrom and cleaning thereof. Alternatively, the cleaning balls are shaped and dimensioned for interference fitting with the plurality of tubes  22 . 
         [0017]    Preferably, the cleaning system  20  comprises a trap  42  disposed proximal to where the-flow diverting system  38  couples with the exhaust  28  of the plurality of tubes  22 . The trap  42  defines one or more openings (not shown) to enable flow of liquid but shaped and dimensioned to impede passage of the plurality of cleaning balls therethrough. This allows the plurality of cleaning balls exiting the plurality of tubes  22  to be caught by the trap  42  and prevents further transport of the plurality of cleaning balls through the rest of the heat exchange system  24 . When in the second operating mode, flow of liquid displaced by the displacement system  30  is re-diverted to draw the plurality of cleaning balls caught by the trap  42  back into the manifold  36 . 
         [0018]    To enable the plurality of cleaning balls to be introduced into the plurality of tubes  22  for cleaning thereof and to be subsequently retrieved, it is first preferred that the displacement system  30  is operable for drawing liquid into the second port  34  and expelling the drawn liquid out of the first port  32  when in the first operating mode and drawing liquid into the first port  32  and expelling the drawn liquid out of the second port  34  when in the second operating mode. It is further preferred that the manifold  36  defines a first chamber  44  and a second chamber  46  interposed by a separator  48 . The separator  48  defines a plurality of apertures (not shown) for fluid communicating the first chamber  44  with the second chamber  46  with each of the plurality of apertures being shaped and dimensioned for impeding passage of the plurality of cleaning balls therethrough. 
         [0019]    The flow diverting system  38  is adapted for fluid communicating the first port  32  of the displacement system  30  and the intake  26  to the first chamber  44  of the manifold  36  while substantially impeding fluid communication of the first port  32  and the exhaust  28  with the second chamber  46  and first chamber  44  respectively when in the first operating mode. In the second operating mode, the flow diverting system  38  is further adapted for fluid communicating the first port  32  and the exhaust  28  to the second chamber  46  and first chamber  44  respectively and substantially impeding fluid communication of each of the first port  32  of the displacement system  30  and the intake  26  with the first chamber  44  of the manifold  36 . 
         [0020]    Preferably, the first chamber  44  of the manifold  36  is shaped and dimensioned for generating a cyclonic vortex flow when liquid is displaced thereinto in the first operating mode. The cyclonic vortex flow is for generating inertia for displacement of the plurality of cleaning balls out of the first chamber  44  and into the intake  26  of the plurality of tubes  22 . The manifold  36  may comprise a ball screening unit (not shown) disposed within the first chamber  44 . After a period of use, a portion of the plurality of cleaning balls may be worn and reduced below an acceptable size for effective cleaning of the plurality of tubes  22 . The ball screening unit defines a plurality of apertures shaped and dimensioned for passaging of a portion of the cleanings balls  40  below the acceptable size therethrough. The cyclonic vortex flow aids in screening and separating of unacceptably-sized portion from acceptably-sized portion of the cleaning balls by the ball screening unit. 
         [0021]    Preferably, the flow diverting system  38  comprises a first entry valve  50  inter-coupling the first port  32  of the displacement system  30  and the first chamber  44  of the manifold  36 , a first exit valve  52  inter-coupling the first chamber  44  of the manifold  36  and the intake  26  of the heat exchange system  24 , a second entry valve  54  inter-coupling the exhaust  28  of the heat exchange system  24  and the first chamber  44  of the manifold  36 , and a second exit valve  56  inter-coupling the second chamber  46  of the manifold  36  and the first port  32  of the displacement system  30 . Each of the first entry valve  50 , the first exit valve  52 , the second entry valve  54  and the second exit valve  56  has an open state and a shut state for respectively enabling and substantially impeding liquid flow therethrough. 
         [0022]    The first entry valve  50  and the first exit valve  52  are in the open state while the second entry valve  54  and the second exit valve  56  are in the shut state when in the first operating mode, and the first entry valve  50  and the first exit valve  52  are in the shut state while the second entry valve  54  and the second exit valve  56  are in the open state when in the second operating mode. Preferably, each of the first entry valve  50 , the first exit valve  52 , the second entry valve  54  and the second exit valve  56  is a check-valve. Alternatively, each of the first entry valve  50 , the first exit valve  52 , the second entry valve  54  and the second exit valve  56  is a solenoid actuated two-way valve. 
         [0023]    The flow diverting system  38  is further adapted and operable for fluid communicating the second port  34  of the displacement system  30  to the intake  26  of the heat exchange system  24  when in the first operating mode and for fluid communicating the second port  34  with the exhaust  28  of the heat exchange system  24  when in the second operating mode. Therefore when in the first operating mode, liquid used for displacing the cleaning balls from the manifold  36  to the intake  26  is drawn from the intake  26 . Similarly when in the second operating mode, liquid drawn from the exhaust  28  for displacing the cleaning balls back into the manifold  36  is subsequently channelled back to the exhaust  28  of the plurality of tubes  22 . The flow diverting system  38  therefore impedes mixing of liquids between the intake  26  and the exhaust  28 . As a temperature difference typically exist between liquid at the intake  26  and liquid at the exhaust  28  of the heat exchange system  24 , impeding mixing of liquids between the intake  26  and the exhaust  28  through the cleaning system  20  mitigates effects to heat-exchange efficiency of the heat exchange system  24  that is contributed by operating the cleaning system  20  therewith. 
         [0024]    Therefore, the cleaning system  20  further comprises a third entry valve  58  inter-coupling the second port  34  of the displacement system  30  and the intake  26  of the heat exchange system  24 , and a third exit valve  60  coupling the second port  34  of the displacement system  30  to the exhaust  28  of the heat exchange system  24 . Each of the third entry valve  58  and the third exit valve  60  is operable between an open state and a shut state for respectively enabling and substantially impeding liquid flow therethrough. 
         [0025]    The displacement system  30  preferably comprises a bi-directional pump  62  arranged in a single pump configuration with the first port  32  and the second port  34  being defined by the bi-directional pump  62 . The bi-directional pump  62  is a centrifugal pump, a positive displacement pump or the like pump adaptable and operable for alternating liquid displacement between two flow directions. Alternatively, the displacement system  30  comprises a first pump  66  and a second pump  68  arranged in a multi-pump configuration with each of the first pump  66  and the second pump  68  being operable for displacing liquid in one flow direction as shown in  FIG. 4  and  FIG. 5 . In the multi-pump configuration, the first port  32  is couplable to an outlet of the first pump  66  and an inlet of the second pump  68 . Preferably, operations of the first pump  66  and the second pump  68  is coordinated by a controller (not shown) for alternating between exhaust of liquid by the first pump  66  from the outlet when in the first operating mode and drawing of liquid by the second pump  68  through the inlet  74  when in the second operating mode. Inlet and outlet (not referenced) of respectively the first pump  66  and the second pump  68  are preferably couplable to the second port  34 . 
         [0026]    When using the multi-pump configuration, the displacement system  30  further comprises a first check-valve  76  inter-coupling the outlet of the first pump  66  and the first port  32  of the displacement system  30 , and a second check-valve  78  inter-coupling the inlet  74  of the second pump  68  and the first port  32  of the displacement system  30 . The first check-valve  76  is for fluid communicating the outlet of the first pump  66  with the first port  32  and the second check-valve  78  for substantially impeding fluid communication between the inlet  74  of the second pump  68  and the first port  32  when in the first operating mode. In the second operating mode, the first check-valve  76  is for substantially impeding fluid communication between the outlet of the first pump  66  and the first port  32  and the second check-valve  78  for fluid communicating the inlet  74  of the second pump  68  with the first port  32  when in the second operating mode. 
         [0027]    In a forgoing manner, a cleaning system is described according to an exemplary embodiment of the invention. Although only one embodiment of the invention is disclosed in this document, it will be apparent to one skilled in the art in view of this disclosure that numerous changes and/or modifications can be made to the disclosed embodiment without departing from the scope and spirit of the invention.