Abstract:
Embodiments of the present invention relate to detecting leaks in a fluid cooling system. One aspect of the present invention concerns an apparatus for detecting leaks in a fluid cooling system that includes a pressure exerting device for applying a pressure on a supply hose and a return hose of the cooling system, and a pressure gauge coupled to the pressure exerting device for detecting a drop of fluid pressure in the cooling system while the pressure is applied. The drop of fluid pressure indicates that there may be a leak in the cooling system.

Description:
BACKGROUND 
     Embodiments of the present invention relate generally to fluid cooling systems. More particularly, embodiments of the present invention relate to a device and method for detecting leaks of coolant in fluid cooling systems. 
     Fluid cooling is commonly used in electronics fabrication and material processing systems because a liquid cooling system is generally self-contained, relatively simple to set up, and can be extended to additional work stations as an operation increases in size. Typically, a fluid cooling system may include a network of rigid pipes and flexible hoses that contain a coolant such as water or a solution of water and glycol. The coolant may be circulated in the cooling system by one or more pumps installed in the system. Portions of the hoses or pipes may be adjacent to materials or media from which the heat is removed by the coolant. In some cooling systems, portions of the hoses or pipes containing the coolant may be submerged in a tank holding the liquid from which heat is removed by the coolant. Once the coolant absorbs the thermal energy from the liquid or material to be cooled, the heated coolant may go through a heat exchanger or radiator to discard the absorbed thermal energy. The coolant at the lower temperature is then returned to the cooling system to continue removing the heat from the liquid or material to be cooled in a closed loop system. 
     A fluid cooling system may develop leaks of coolant over time due to fatigue in the joints of the pipes and hoses, corrosion, or accidental damages to the pipes and hoses. Such leaks in the cooling system may disrupt the operation of the equipment being cooled by the cooling system or contaminate sensitive materials and components being processed or fabricated by the equipment. In order to temporarily maintain continuous operation of the cooling system, more coolant may need to be added to the cooling system to replace the leaked coolant. 
     Inspecting a cooling system to detect a leak is generally difficult due to the system&#39;s extensive network of pipes and hoses. Further, the operation of the equipment being cooled and the cooling system may need to be shut down in order to determine whether there is a leak in the cooling system. 
     It is thus desirable to have a device and method to quickly detect a leak in a fluid cooling system. 
     BRIEF SUMMARY 
     Exemplary embodiments of the present invention relate to an apparatus and method for detecting leaks in a fluid cooling system. The embodiments of the present invention may be implemented in a stand-alone leak detection device or incorporated into systems or equipment including fluid cooling systems that may develop leaks over time. 
     One aspect of the present invention concerns an apparatus for detecting leaks in a fluid cooling system that may include a pressure exerting device for applying a pressure on a flexible hose portion of the cooling system, and a pressure gauge coupled to the pressure exerting device for detecting a drop of fluid pressure in the cooling system while the pressure is applied. The drop of fluid pressure in the gauge indicates that there may be a leak in the fluid cooling system. 
     Another aspect of the present invention concerns a method for detecting leaks in a fluid cooling system that includes a supply valve and a return valve in the system&#39;s inlet and outlet, respectively. The method may include closing the return valve, applying a pressure exerting device on a flexible hose portion of the cooling system, wherein the pressure exerting device is coupled to a pressure gauge, closing the supply valve, and observing the pressure gauge for a drop of fluid pressure in the cooling system. The drop in the fluid indicates that there may be a leak in the fluid cooling system. 
     The details of the preferred embodiments of the present invention, both as to its structure and operation, are described below in the Detailed Description section in reference to the accompanying drawings. The Summary is intended to identify key features of the claimed subject matter, but it is not intended to be used to limit the scope of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a diagram showing an example fluid cooling system to which embodiments of the present invention may be applied to detect leaks in the cooling system; 
         FIG. 2  illustrates a perspective view of a device for detecting leaks in a fluid cooling system, according to an exemplary embodiment of the present invention; 
         FIG. 3  illustrates a top view of a device for detecting leaks in a fluid cooling system, according to an exemplary embodiment of the present invention; 
         FIG. 4  illustrates a back view of a device for detecting leaks in a fluid cooling system, according to an exemplary embodiment of the present invention; 
         FIG. 5  illustrates a side view of a device for detecting leaks in a fluid cooling system, according to an exemplary embodiment of the present invention; 
         FIG. 6  illustrates a front view of a device for detecting leaks in a fluid cooling system, according to an exemplary embodiment of the present invention; 
         FIG. 7  illustrates a side view of a device for detecting leaks in a fluid cooling system, according to another exemplary embodiment of the present invention; 
         FIG. 8  is a flow chart of an exemplary process for detecting leaks in a fluid cooling system, according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description provides certain example embodiments of the present invention. In this description, reference is made to the drawings wherein like parts are designated with like numerals throughout. 
     The present invention relates to devices and methods for detecting leaks in a fluid cooling system. Embodiments of the present invention may be implemented as stand-alone leak detection devices or incorporated into systems or equipment that include fluid cooling systems. For example, the embodiments may be incorporated into a semiconductor processing system that requires continuous cooling to remove heat from a reservoir containing a high-temperature fluid that drains from a washing step in a semiconductor processing operation. As another example, embodiments of the present invention may be integrated with alarm systems to inform operators of possible leaks in the fluid cooling systems. 
     One embodiment of the present invention includes a device for detecting leaks in a fluid cooling system. The cooling system may be configured to remove heat from heat-generating equipment such as a semiconductor scrubbing system. Although embodiments of the present invention are described in the context of a fluid cooling system for a semiconductor scrubbing system as an example, it will be appreciated by those skilled in the art that embodiments described herein may be applicable for detecting leaks in fluid cooling systems used with other equipment and systems that generate heat in their operation such as engines and machinery with moving parts. 
     A semiconductor scrubbing system typically sprays water on the surface of a material that is being processed and currently at a generally high temperature to quickly lower the temperature of the material. The scrubbing water, which becomes generally warm after contacting the hot material, may flow into a holding tank below a scrubbing station.  FIG. 1  illustrates such an example tank  101  for holding warm scrubbing water  102  that drains from a heat-generating source such as a scrubbing system (not shown). Waste in the holding tank  101  may be removed from the holding tank  101  through outlet  104 . Make-up fluid may be added to the holding tank  101  through inlet  103 . 
     A fluid cooling system  100  may be used to cool the generally warm scrubbing water  102  in the holding tank  101  so that the water  102  may be reused in the scrubbing process. The fluid cooling system  100  typically includes an inlet pipe  105  in which a cooling fluid  113  enters the cooling system  100  and an outlet pipe  106  through which the cooling fluid  113  exits the cooling system  100 . The coolant fluid  113  in the cooling system  100  may be water, deionized water, or a solution of water and glycol. The fluid cooling system  100  may include a supply valve  107  and a return valve  108  for respectively turning off the flow of fluid in the inlet pipe  105  and outlet pipe  106  when it is necessary to stop the flow of the cooling fluid. 
     The fluid cooling system  100  may include flexible hose sections  109  and  110  as part of the inlet pipe  105  and outlet pipe  106 , respectively, where a device  111  for detecting leaks in the cooling system  100  may be applied. The leak detection device  111  may be applied to another flexible hose portion in the fluid cooling system between the supply valve  107  and a return valve  108 . The flexible hose sections  109 - 110  may be made of a high-temperature and reinforced rubber material. The fluid cooling system  100  may further include a heat exchanger  112  for extracting thermal energy from the scrubbing water  102  that is being cooled by the fluid cooling system  100 . The heat exchanger  112  may include a generally long section of pipe or hose that is submerged in the scrubbing water  102  in holding tank  101  and configured in a serpentine pattern to maximize the contact surface between the cooling system  100  and the scrubbing water  102 . 
     As the cooling fluid flows through the heat exchanger  112 , the cooling fluid  113  is heated up by the generally warm scrubbing water  102  outside the heat exchanger  112  and thus lowering the temperature of the scrubbing water  102 . The cooling fluid  113 , now at a temperature higher than when it entered through inlet  105 , exits the cooling system  100  through the outlet pipe  106 . The temperature of the cooling fluid  113  that exits the cooling system  100  may then be lowered using another heat exchanger or radiator (not shown in  FIG. 1 ). 
     Due to the continuous operation of the cooling system  100  at a generally high temperature, leaks may develop in the pipes, hoses, and connectors of the cooling system over time. These leaks may be caused, for example, by faulty seals or connections in pipes, hoses, and other components in the cooling system  100 . Such leaks may require more fluid to be added to the cooling system  100  to replace the lost fluid, or even a shut-down of the cooling system  100  and the equipment that produces the scrubbing water  102  being cooled by the cooling system, in order to identify and repair the leaks. 
     Embodiments of the present invention may be used to quickly determine whether there may be a leak in the fluid cooling system  100  without the need for shutting down the equipment that generates the material being cooled, such as the scrubbing water  102 . In one embodiment, a device for detecting leaks in the cooling system  100 , as described with reference to  FIGS. 2-7  may be applied to either flexible hose section  109  or flexible hose section  110  of the cooling system  100 . 
       FIG. 2  illustrates a perspective view of a device  200  for detecting leaks in a fluid cooling system  100 , according to an exemplary embodiment of the present invention. The leak detection device  200  may include a pair of clamps  201 - 202  for holding a portion of flexible hose  204  of the cooling system  100 . The clamps  201 - 202  may be held together by a connecting block  203 . The leak detection device  200  may include a block  205  attached to the top of the clamp  201  to accommodate a pressure gauge  206  and allow the pressure gauge  206  to be adjusted relative to and through block  205 . The pressure gauge  206  may include a pressure sensing pin  207  which extends downward from the lower portion of the pressure gauge  206 . The amount of pressure that the pressure sensing pin  207  exerts on the flexible hose section  204  may be varied by adjusting the position of the pressure gauge  206  relative to the block  205 . The leak detection device  200  may include an adjusting mechanism for adjusting and locking the position of the pressure gauge  206  against the block  205 , and thus adjusting and locking the pressure that the pressure sensing pin  207  exerts on the flexible hose section  204 . An example of such an adjusting and locking mechanism is illustrated and described below with reference to  FIG. 3 . 
       FIG. 3  illustrates a top view of the device  200  for detecting leaks in a fluid cooling system  100 , according to an exemplary embodiment of the present invention. In the illustrated top view, upper clamp  301  of the leak detection device  200  is shown above a flexible hose section  304  of the cooling system  100  which the device  200  is being applied to. Block  305  is attached to the top of upper clamp  301  and accommodates a pressure gauge  306 . In one embodiment, the leak detection device  200  may further include a pressure adjusting screw  308  positioned in block  305  to allow a pressure sensing pin  207  of the pressure gauge  306  to be adjusted relative to the flexible hose section  304 . Once a desired initial pressure on the flexible hose section  304  is established by moving the pressure gauge  306  against block  305 , the screw  308  may be tightened to keep the pressure gauge  306  in a fixed position relative to the block  305 . The pressure sensing pin  207  thus maintains the pressure level against the flexible hose section  304  at a fixed value at the start of the leak detection test. 
       FIG. 4  illustrates a rear view of the device  200  for detecting leaks in a fluid cooling system  100 , according to an exemplary embodiment of the present invention. In the illustrated rear view, a flexible hose section  404  of the cooling system  100  is shown laying above the lower clamp  402  of the leak detection device  200 . Clamps  401 - 402  of the leak detection device  200  may be held together by a connecting block  403 . The leak detection device  200  may include a block  405  attached above the upper clamp  401  for accommodating a pressure gauge  406 . The pressure sensing pin  207  of the pressure gauge  406  may extend from the pressure gauge  406  through block  405  and upper clamp  401  to reach the exterior surface of the flexible hose section  404 . The pressure sensing pin of the pressure gauge  406  would sense the pressure of the fluid in the flexible hose section  404  during a leak detection test. If there is a leak of fluid in the cooling system  100 , the pressure gauge  406  would indicate a drop  409  in the pressure of the fluid in the cooling system  100  after a brief waiting period, for example, of about 10 seconds. 
       FIG. 5  illustrates a side view of the device  200  for detecting leaks in a fluid cooling system  100 , according to an exemplary embodiment of the present invention. Clamps  501 - 502 , connecting block  503 , block  505 , adjusting screw  508 , gauge  506 , and pressure pin  507  of the leak detection device  200  are the same as those described with reference to  FIGS. 2-4 . The side view of the leak detection device  200  shows an initial deflection  509  in the flexible hose  504  of the cooling system  100 . The initial deflection  509  corresponds to an initial pressure that the pressure sensing pin  507  of the leak detection device  200  exerts on the flexible hose section  504 . The initial pressure may be set by adjusting screw  508  at block  505 . If there is a leak of fluid in the cooling system  100 , the pressure of the fluid inside the flexible hose  504  would drop from the initial fluid pressure after a brief waiting period, such as about 10 seconds. This drop in fluid pressure would be sensed by the pressure sensing pin  507  and indicated on the pressure gauge  506 . 
       FIG. 6  illustrates a front view of the device  200  for detecting leaks in a fluid cooling system  100 , according to an exemplary embodiment of the present invention. The leak detection device  200  includes an upper clamp  601  and a lower clamp  602  to receive a flexible hose  604  which is part of the fluid cooling system  100 . The leak detection device  200  may include a block  605  that is attached to upper clamp  601  to accommodate a pressure gauge  606 . The pressure sensing pin  607  lightly touches the exterior surface of the flexible hose  604  to sense an initial pressure of the fluid inside the flexible hose  604 , as established by an adjustment of the pressure gauge  606  relative to block  605 . A subsequent drop of fluid pressure in the flexible hose  604  after a brief waiting period would indicate a possible leak in the fluid cooling system  100 . 
       FIG. 7  illustrates a side view of a device  700  for detecting leaks in a fluid cooling system  100 , according to another exemplary embodiment of the present invention. The leak detection device  700  may include a pair of handles  721  and  722  similar to those of a locking pair of pliers. The handles  721  and  722  are respectively attached to clamps  701  and  702 . The clamps  701 - 702  may be held together by an adjustable connector  703 . The adjustable connector  703  may include, for example, a spring-loaded mechanism for adjusting the space between the clamps  701  and  702  depending on a setting of an adjusting nut  724  at the end of the handle  721 . The handle  722  may include a locking lever  723  to lock the handles  721  and  722  in a fixed position and to release the handles  721  and  722  from the locked position, similarly to the operation of a locking lever in a conventional pair of locking pliers. 
     The leak detection device  700  may include a block  705  positioned on the top of the upper clamp  701  to receive the lower portion of a pressure gauge  706 . A pressure sensing pin  707  extends from the lower portion of the pressure gauge  706  and protrudes through clamp  701  to reach the exterior surface of flexible hose section  704 . The tension that the pressure sensing pin  707  exerts on the flexible hose section  704  may be adjusted by sliding the pressure gauge  706  vertically through aligning holes in block  705  and clamp  701  until the pressure gauge  706  indicates a desired initial pressure. The position of the pressure gauge  706  relative to block  705  may then be locked in place by tightening a screw  708  in block  705  against the lower portion of pressure gauge  706 . 
     If there is a leak of fluid from the cooling system  100 , the pressure of fluid  713  in the flexible hose  704  would drop from the initially established pressure after a brief waiting period of time such as about 10 seconds. The drop of fluid pressure in the flexible hose  704  may be relatively small, for example, from 15 psi to 12 psi. The pressure gauge  706  would register such a drop in the fluid pressure in the cooling system  100 . 
     In another embodiment of the present invention, a device for detecting leaks in a fluid cooling system as described with reference to  FIGS. 2-7  may be coupled to an alarm to indicate that a leak has been detected in the fluid cooling system. The alarm may be an audible alarm, a visual alarm, or a remote device to inform an operator or a control system of the leak. In still another embodiment, a device for detecting leaks in a fluid cooling system may be coupled to a shut-off mechanism for temporarily shutting down the fluid cooling system if a leak is detected and considered relatively severe based on a predetermined level of fluid pressure drop in the cooling system. 
       FIG. 8  is a flow chart of an exemplary process for detecting a leak in a fluid cooling system, according to an embodiment of the present invention. In one application of a fluid cooling system  100 , an operator may notice that make-up coolant needs to be added to the cooling system  100  to replace lost coolant more frequently than a normal schedule to replace coolant loss due to evaporation, for example. The operator may use a leak detection device  111  to determine whether a leak might have developed in the cooling system  100 . At step  801 , the operator may close a return valve  108  to shut off the flow of the cooling fluid in the outlet pipe  106 . The operator may, at step  802 , apply the leak detection device  111  to the flexible hose section  110  coupled to the outlet pipe  106 , or the flexible hose section  109  coupled to the inlet pipe  105 , to determine whether a leak of the fluid  113  may have developed in the cooling system  100 . 
     The operator further closes the supply valve  107  to shut off the flow of the cooling fluid  113  in the inlet pipe  105 , at step  803 . Once the fluid in the cooling system  100  is isolated within the closed section of the cooling system  100  between the supply valve  107  and the return valve  108 , the operator may observe a pressure gauge  206  attached to the leak detection device  111  for a possible drop of the pressure of the fluid in the cooling system  100 . For example, the pressure gauge  206  might have a reading of 15 psi when the leak detection device  111  was first applied to either of the flexible hose sections  109 - 110 , at step  801 . After the supply valve  107  was turned off in step  803  and the operator waits for approximately 10 seconds, the pressure gauge  206  may now show a reading of 12 psi. The drop of 3 psi in the pressure of the cooling fluid indicates that there may be a leak in the cooling system  100  between the supply valve  107  and the return valve  108 . 
     The subject matter described above is provided by way of illustration only and should not be construed as limiting. Various modifications and substitutions of the described components and operations can be made by those skilled in the art without departing from the spirit and scope of the present invention defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures. As will be appreciated by those skilled in the art, the systems, methods, and procedures described herein can be embodied in a programmable computer, computer executable software, or digital circuitry. The software can be stored on computer readable media. For example, computer readable media can include a floppy disk, RAM, ROM, hard disk, removable media, flash memory, a “memory stick”, optical media, magneto-optical media, CD-ROM, etc. 
     The flowchart and block diagrams in the figures described above illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a component, segment, or portion of code, which includes one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.