Abstract:
An apparatus for temperature regulation comprising a three-way valve, a first channel for delivering fluid to said valve, a device for measuring fluid temperature, a bypass channel connected to said valve, a second channel connected to said bypass channel, and fluid loop connected to said valve and said second channel; and a heat exchanger, at least of a portion of said fluid loop contained within said heat exchanger, wherein said valve directs the fluid into said bypass channel or said fluid loop depending on the fluid temperature.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to a thermolator, and more particularly to a thermolator set-up for cooling oil.  
         [0003]     2. Related Art  
         [0004]     Thermolators are employed throughout the blowmolding process to regulate the temperature of oil that is cycled through the molds. Oil can acquire heat from the molds, and sometimes requires cooling before the oil can again be sent to the molds. Thermolators are used to cool the oil by piping it through a heat exchanger. The heat exchanger usually contains water, which absorbs heat from the oil that is passed through.  
         [0005]     Thermolators known in the art continually send oil through the heat exchanger. However, the oil is not always hot enough to require cooling, and often will reach the desired temperature on its own in a short amount of time. The continual, and often unnecessary sending of oil through the heat exchanger causes the water in the heat exchanger to boil-off and leave mineral deposits. This results in decreased efficiency and contributes to breakdown of the heat exchanger.  
         [0006]     Heat exchangers present in thermolators for temperature regulation can begin to lose efficacy within the first two months of use, and experience complete failure within 6-10 months. Heat exchangers known in the art are sealed, and therefore must be replaced when they break down. Replacement is costly, and so is the loss in productivity from the time the heat exchanger begins to fail until its replacement.  
         [0007]     Prior art thermolators do not allow strict temperature control of the oil that emerges from the heat exchanger. These temperature fluctuations cause variation in volume of the blowmolded product, increasing the number of defective PPMs and cause variations in container volume. Product discrepancies, such as a container that doesn&#39;t hold the required amount of contents or a container that requires more contents to be filled, result in customer complaints.  
         [0008]     What is needed then is an improved thermolator that does not constantly send oil through the heat exchanger, provides less variable temperature control, does not rapidly break-down, and minimizes or prevents water boil-off.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     The present invention is an apparatus having a heat exchanger that can be used to cool a substance. The apparatus includes a first channel which delivers fluid from molds to a three-way solenoid valve, and a device for measuring the temperature of the fluid that enters the valve. The valve is also connected to a bypass channel as well as a fluid loop, such that fluid entering the valve via the first channel can either proceed through the heat exchanger or bypass it entirely using the bypass channel. Both the bypass channel and the fluid loop are connected to a second channel, which carries the fluid from the apparatus to the molds.  
         [0010]     In an exemplary embodiment, the apparatus is used to control the temperature of the fluid. In a further preferred embodiment, the apparatus is used to control the temperature of the fluid within a predetermined range. The fluid can be, for example, oil.  
         [0011]     In one embodiment of the present invention, a fluid above a predetermined temperature range is directed through the fluid loop, which is contained within the heat exchanger. A fluid with a temperature below the predetermined range is allowed to bypass the heat exchanger. The apparatus can further include a timer which measures the temperature at certain intervals and prompts the valve to direct the fluid to either the bypass channel or the fluid loop. In a preferred embodiment, the set period of time is 60 seconds.  
         [0012]     In a further embodiment, the heat exchanger includes an inlet for ingress of a temperature regulating substance, and an outlet for egress of the temperature regulating substance.  
         [0013]     In another embodiment, the apparatus of the present invention includes a system for circulating a temperature regulating substance through the heat exchanger. In an exemplary embodiment, the system is for continuous circulation of the temperature regulating substance. The temperature regulating substance can be, for example, water.  
         [0014]     In an alternate embodiment the apparatus comprises a heat exchanger having an inlet for ingress of a temperature regulating substance and an outlet for egress of a temperature regulating substance, and a mechanism for continuously circulating and controlling the temperature of the temperature regulating substance between the outlet and in the inlet. In this embodiment, the apparatus is used to control the temperature of a fluid.  
         [0015]     The present invention also speaks to a method of cooling a substance comprising providing a heat exchanger, measuring the temperature of an incoming substance before it enters the heat exchanger, and allowing the fluid to proceed through either a bypass channel or the heat exchanger. Fluid is directed to the bypass channel if the fluid temperature is below a predetermined temperature range. If the fluid temperature is above a certain range, the fluid is directed to the fluid loop and continues through the heat exchanger. The fluid can be directed by, for example, a three way valve.  
         [0016]     In a further embodiment, the method also includes the step of continuously flowing a temperature regulating substance through the heat exchanger via an inlet and outlet. In a preferred embodiment, the temperature regulating substance is water and the fluid is oil. In an additional preferred embodiment, the method is for controlling the temperature of oil circulated through a mold in the blowmolding process.  
         [0017]     The present invention is superior to the prior art in several respects. First, the invention eliminates the requirement in the prior art that all fluid be sent through the heat exchanger. This prevents unnecessary cooling by allowing a fluid to bypass the heat exchanger through the use of the three-way valve and bypass channel. This improvement reduces the amount of time spent during the cooling processes thereby increasing production, and minimizes use of the heat exchanger, possibly extending its life. Ultimately, efficiency is greatly enhanced.  
         [0018]     Another advantage of the present invention is the addition of a delay timer which measures the temperature of the fluid arriving from the molds at certain intervals to help determine whether the fluid should be directed to the bypass channel or the fluid loop. This further contributes to the enhanced efficiency of the present invention by reducing the amount of fluid sent through the heat exchanger. The presence of a temperature measuring device to determine whether the fluid requires heating or cooling also prevents the unnecessary expenditure of energy by minimizing use of the heat exchanger.  
         [0019]     The apparatus provides for the continuous circulation of a temperature regulating substance through the heat exchanger, which eliminates the problem of boil-off and mineral deposits. As result, efficiency of the apparatus is increased and operation costs are reduced because the apparatus will require minimal repair work. Since the present invention does not employ the sealed heat exchanger of the prior art, replacement costs are minimized.  
         [0020]     Additionally, the apparatus allows for constant temperature control. The elimination of temperature fluctuations subsequently eliminates variation in volume of the packages produced. The result is the consistent formation of the product, reduced waste, and increased efficiency in manufacture. Specifically, volume variations are substantially reduced and customers are pleased with the product.  
         [0021]     This invention satisfies a long felt need for a heating/cooling device that does not rapidly deteriorate and require frequent, costly replacement. Also, the invention improves upon the prior art by allowing for constant temperature control and increasing system efficiency.  
         [0022]     Further objectives and advantages, as well as the structure and function of preferred embodiments will become apparent from a consideration of the description, drawings, and examples. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.  
         [0024]      FIG. 1  depicts a prior art apparatus;  
         [0025]      FIG. 2  depicts an exemplary embodiment of the apparatus according to the present invention;  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]     Embodiments of the invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. While specific exemplary embodiments are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations can be used without parting from the spirit and scope of the invention. All references cited herein are incorporated by reference as if each had been individually incorporated.  
         [0027]      FIG. 1  depicts a thermolator  100  known in the prior art. In  FIG. 1A , the thermolator is in the oil heating condition, where the oil is acquiring heat from the manufacturing process (i.e. from molds, or the oil is being heated to a desired operating temperature). In the heating condition, water does not flow through the heat exchanger. The water inside the heat exchanger is exposed to temperatures of about 250 degrees or more, which results in water boil off that leaves mineral deposits on the inside of the heat exchanger.  FIG. 1B  shows the prior art themolator during the oil cooling condition, meaning that the oil has not been heated externally. In this condition water flows through the thermolator to maintain the oil temperature in the desired heating range. Because the thermolator is in the cooling condition, for example, less than 5% of the time, there is insufficient circulation to maintain a full water level. Further, the water that flows through the heat exchanger is not sufficient to remove the mineral deposits that accumulate the remaining 95% of the time. These mineral deposits lead to a rapid loss of efficiency and a complete breakdown shortly thereafter.  
         [0028]      FIG. 2  illustrates an exemplary embodiment of the apparatus  200  of the present invention.  FIG. 2A  depicts the apparatus in a heating condition. In this condition, a fluid flows through the bypass channel  206 . During the manufacture of containers via blowmolding, fluid from molds enters the first channel  202 , which carries the fluid into the three-way valve,  204 . The valve is connected to a bypass channel  206 , and a fluid loop  210 . The fluid loop  210  is contained within the heat exchanger  212 . The fluid loop can be, for example, a coil, through which the fluid flows. According to the present invention, the fluid only flows through the fluid loop  210  when its temperature needs to be adjusted, as explained in more detail below. Although useful for cooling any process fluid, in this exemplary embodiment where the thermolator is used in a blowmolding apparatus, the fluid is oil.  
         [0029]     In the present invention, a temperature regulating substance continually circulates through the heat exchanger  212 . The temperature regulating substance serves as a heat sink for maintaining the temperature of the fluid within a predetermined range. In the preferred embodiment, the temperature regulating substance is water, but other fluid regulating substances compatible with the invention are, for example, coolants. The apparatus has an inlet for ingress of the temperature regulating substance and an outlet for egress.  
         [0030]      FIG. 2A  depicts the configuration of the invention when the fluid does not need to be cooled, i.e. when the fluid temperature is within a desired, predetermined temperature range, or an operating range. In  FIG. 2A , the valve  204  directs the fluid through the bypass channel  206 . Because the fluid temperature in the valve  204  is below the desired temperature range, the fluid is directed to the bypass channel  206 .  
         [0031]     The apparatus  200  includes a device for measuring the fluid temperature, such as a thermometer, thermocouple, etc. The temperature may be measured, for example, in the valve  204 , or prior to entering the valve  204 . The invention may optionally include a timer, which implements a delay between the time the temperature is measured and the action of the valve, directing the oil to either the bypass channel  206  or the fluid loop  210 . The delay can be, for example, between 30 and 90 seconds.  
         [0032]     In the preferred embodiment of the present invention, the thermolator  200  is for cooling oil used in the blowmolding process. Oil arrives from the molds and is brought to the valve  204  via a first channel  202 . In such an embodiment, it can be desirable to maintain the oil between a temperature of about 273.5° and about 276.5°. The oil is measured at predetermined intervals in order to help maintain this strict temperature control.  
         [0033]     As pictured in  FIG. 2A , the oil is being directed through the bypass channel  206 . If at any time the temperature of the oil is too high, the system measures the oil again after, for example, 30-60 seconds. If the oil has returned to the desired temperature range at this time, then the oil continues through the bypass channel  206 . If the oil is still above the desired temperature range, then the fluid is re-directed to the fluid loop  210 .  
         [0034]     This system of continual measurement creates a stabilization period. This stabilization period allows the oil to return to an operating temperature on its own, without the unnecessary expense of cooling the oil in the heat exchanger. The implementation of the delay timer is a significant improvement over the prior art, which is plagued with temperature fluctuations. Using such an embodiment, the temperature of the fluid can be regulated within, for example, three degrees, even when the predetermined temperature range for the fluid is above the boiling point of the temperature regulating substance.  
         [0035]      FIG. 2B  illustrates the passing of fluid through the fluid loop  210  contained within the heat exchanger  212 , into the second channel  208 , and back to the molds. This configuration exists when temperature regulation of the fluid is needed, i.e. when the temperature of the fluid is outside the desired, predetermined range or operating temperature. Here the fluid temperature is above the desired temperature range. Thus, the fluid is cooled by sending it through the heat exchanger  212  via the fluid loop  210 .  
         [0036]     In this cooling process of the preferred embodiment, oil having a temperature above the desired range is directed by the valve  204  to the fluid loop  210 . The fluid loop  210  is contained within the heat exchanger  212 , and connected to second channel  208 . The second channel  208  carriers the cooled oil back to the molds. The second channel  208  also receives oil from bypass channel  206 .  
         [0037]     An inlet,  214  carries water to the heat exchanger and an outlet  216  carries water out of the thermolator. The inlet  214  and the outlet  216  are part of a system that allows for continuous circulation of water through the thermolator. This continuous circulation of water provided for in the present invention overcomes the problem of accumulating mineral deposits in prior art heat exchangers. In the present invention where water constantly flows, water is not endlessly exposed to the high temperature of the heat exchanger. The introduction of “fresh” water to the heat exchanger prevents boil-off. Any evaporation that may occur is inconsequential because water is continually replenished. In the event that mineral deposits form, they are immediately flushed out by the perpetually moving system.  
         [0038]     The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.