Patent Publication Number: US-2022234260-A1

Title: Isostatic press apparatus enabling rapid heating and cooling using pressurized liquid circulation fan

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an isostatic press apparatus for pressing a workpiece using a pressurized liquid, and more particularly to an isostatic press apparatus enabling rapid heating and cooling using a pressurized liquid circulation fan that is capable of performing isostatic pressing while heating or cooling a workpiece by heating or cooling a pressurized liquid. 
     Description of the Related Art 
     In general, an isostatic press apparatus presses a workpiece using the pressure of a fluid that is supplied to a pressure vessel at high pressure. 
     An isostatic press apparatus is classified as a warm isostatic press (WIP) apparatus or a hot isostatic press (HIP) apparatus, which performs pressing in the state of heating a workpiece, and a cold isostatic press (CIP) apparatus, which performs pressing in the state of cooling a workpiece. The HIP apparatus uses a gaseous fluid, and the WIP apparatus and the CIP apparatus use a liquid. The HIP apparatus presses a workpiece using a gaseous fluid heated to a high temperature ranging from 300° C. to 2500° C., the WIP apparatus presses a workpiece using a liquid heated to 250° C. or lower, and the CIP apparatus presses a workpiece using a liquid at room temperature. Therefore, these isostatic press apparatuses are used for different kinds of products. 
     In the case of the WIP apparatus, it usually takes a long time to heat or cool a workpiece, and a workpiece that has undergone compression processing is withdrawn in a high-temperature state. Therefore, in the case of a workpiece that is transformed in a high-temperature state, it is required to cool the workpiece before withdrawing the same. However, in this case, a springback phenomenon in which at least a portion of the compressed workpiece returns to the original shape thereof occurs, and thus the effect of compression processing is reduced. 
     The present applicant has developed technology for solving the above problem, disclosed in Korean Patent Registration No. 10-1708490 (hereinafter referred to as “Conventional Art 1”) and Korean Patent Registration No. 10-2138354 (hereinafter referred to as “Conventional Art 2”). 
     Conventional Art 1 is configured to selectively perform cold isostatic pressing and hot isostatic pressing by cooling or heating a heat exchanger using a selective supply unit. Conventional Art 2 is configured to circulate a fluid using a tray in order to quickly change the temperature of the pressurized fluid, thereby rapidly processing a workpiece with uniform quality. 
     In this regard, Korean Patent Registration No. 10-1311563 (hereinafter referred to as “Conventional Art 3”) discloses an isostatic press apparatus in which the circulation of a pressurized medium gas is controlled by a forced circulation unit. 
     However, because Conventional Art 1 and Conventional Art 2 do not have a separate configuration for circulating a pressurized medium, it takes a long time to heat and cool the pressurized medium. Although Conventional Art 3 has a forced circulation unit for forcibly circulating a pressurized medium, it has a problem in which a motor for driving a fan is damaged due to the inflow of the pressurized medium into the motor and a pressure difference. 
     SUMMARY OF THE INVENTION 
     The present invention has been made to solve the above problems, and it is an object of the present invention to provide an isostatic press apparatus enabling rapid heating and cooling using a pressurized liquid circulation fan in which a heating/cooling supply unit, which includes a heater and a cooler, heats or cools a heat exchange medium that is to be supplied to a heat exchanger, and thus a pressurized liquid is rapidly heated or cooled, thereby achieving hot isostatic pressing and cold isostatic pressing and rapidly cooling a workpiece before withdrawing the same, thus preventing or minimizing a springback phenomenon or thermal deformation of the workpiece. 
     It is another object of the present invention to provide an isostatic press apparatus enabling rapid heating and cooling using a pressurized liquid circulation fan in which a pressure equalization adjustment unit equalizes the pressure in a motor accommodation unit, in which a circulation fan motor is accommodated, with the pressure in a pressure vessel in accordance with changes in the pressure in the pressure vessel, thereby preventing introduction of pressurized liquid into the motor accommodation unit due to a pressure difference, thus preventing damage to the circulation fan motor. 
     It is still another object of the present invention to provide an isostatic press apparatus enabling rapid heating and cooling using a pressurized liquid circulation fan in which the pressurized liquid circulation fan circulates a pressurized liquid and a tray forms a circulation flow of the pressurized liquid in a pressure vessel, thereby making it possible to rapidly heat or cool the pressurized liquid and to maintain the temperature of the pressurized liquid uniform for a long time, thus enabling tasks requiring rapid processing and minimizing defects in a workpiece. 
     In accordance with the present invention, the above and other objects can be accomplished by the provision of an isostatic press apparatus enabling rapid heating and cooling, the isostatic press apparatus including a pressure vessel configured to press a workpiece using the pressure of a pressurized liquid, a heat exchanger mounted in the pressure vessel, the heat exchanger being configured to exchange heat with the pressurized liquid in order to heat or cool the pressurized liquid, a heating/cooling supply unit configured to heat or cool a heat exchange medium that is to be supplied to the heat exchanger in order to heat or cool the heat exchanger, a pressurized liquid circulation fan disposed in the pressure vessel, the pressurized liquid circulation fan being configured to circulate the pressurized liquid in the pressure vessel, a circulation fan motor configured to rotate the pressurized liquid circulation fan, a motor accommodation unit formed so as to be isolated from the pressure vessel to accommodate the circulation fan motor therein, and a pressure equalization adjustment unit configured to increase or decrease the internal pressure in the motor accommodation unit to match the internal pressure in the pressure vessel in order to prevent the pressurized liquid from leaking to the motor accommodation unit due to a difference in pressure between the pressure vessel and the motor accommodation unit. 
     The pressure equalization adjustment unit may include a bellows member disposed between the pressure vessel and the motor accommodation unit. The bellows member may expand or contract in accordance with an increase or decrease in pressure in the pressure vessel in order to adjust the pressure in the motor accommodation unit. 
     The bellows member may be formed in a manner such that multiple ring-shaped metal plates are stacked and the inner circumferences of neighboring plates and the outer circumferences of neighboring plates are alternately bonded. 
     The isostatic press apparatus may further include an insulating liquid charged in the motor accommodation unit in order to facilitate a change in pressure in the motor accommodation unit in response to the operation of the pressure equalization adjustment unit. 
     The heat exchanger may include a plurality of thermally conductive plates stacked on one another, a medium passage formed in the plurality of thermally conductive plates to allow the heat exchange medium to pass therethrough, and a circulation passage formed in the plurality of thermally conductive plates to allow the pressurized liquid to pass therethrough. The medium passage and the circulation passage may not communicate with each other. 
     The heat exchanger may further include a central supply portion, formed in the center of the heat exchanger so as to communicate with one end of the circulation passage and to allow the pressurized liquid circulation fan to be disposed therein so that the pressurized liquid is supplied thereto from the circulation passage or is supplied therefrom to the circulation passage by the pressurized liquid circulation fan, and a seating supply portion, formed so as to communicate with a tray in which the workpiece is seated and the opposite end of the circulation passage so that the pressurized liquid that has passed through the circulation passage is supplied to the tray or the pressurized liquid that has passed through the tray is supplied to the circulation passage. 
     The isostatic press apparatus may further include a tray configured to allow the workpiece to be seated therein in order to carry the workpiece into or out of the pressure vessel. The tray may include inlet/outlet holes, formed in the upper and lower portions thereof to allow the pressurized liquid to be introduced into and discharged from the tray so that the pressurized liquid forms a circulation flow in the tray, and a tray wall, surrounding the peripheries of the inlet/outlet holes and partitioning the space in the pressure vessel into a seating space in which the workpiece is received and a space between the tray and the pressure vessel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a side-sectional view schematically showing an isostatic press apparatus enabling rapid heating and cooling using a pressurized liquid circulation fan according to an embodiment of the present invention; 
         FIG. 2  is a side-sectional view schematically showing a heat exchanger of the isostatic press apparatus enabling rapid heating and cooling using a pressurized liquid circulation fan according to an embodiment of the present invention; and 
         FIG. 3  is a side-sectional view schematically showing the operational state of a motor accommodation unit of the isostatic press apparatus enabling rapid heating and cooling using a pressurized liquid circulation fan according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. 
     As shown in  FIG. 1 , an isostatic press apparatus  100  enabling rapid heating and cooling using a pressurized liquid circulation fan  150  according to an embodiment of the present invention may include a pressure vessel  110 . 
     The pressure vessel  110  may be filled with a pressurized liquid, and may perform processing on a workpiece received therein in a manner of uniformly pressing the periphery of the workpiece using the pressurized liquid. 
     In the embodiment, “processing” refers to all kinds of tasks for transforming a workpiece, for example, a task of pressing a workpiece to change the shape thereof, a task of compressing powder to a predetermined shape, a task of pressing a workpiece to densify the same, a task of pressing a workpiece to change the texture thereof, and a task of pressing workpieces to diffusion-bond the same. 
     The pressure vessel  110  may be formed in a cylindrical shape in which only one of the upper portion and the lower portion thereof is open, or both the upper portion and the lower portion thereof are open. The pressure vessel  110  may be provided with a lid  115  to open and close the open upper portion, the open lower portion, or both the open upper portion and the open lower portion. 
     The lid  115  may be mounted to the pressure vessel  110  so as to open and close the pressure vessel  110  by means of a lid opening/closing mechanism. The lid  115  may include an insertion portion, which is inserted into the pressure vessel  110  to seal the open portion of the pressure vessel  110 . The insertion portion of the lid  115  has an outer diameter corresponding to the inner diameter of the pressure vessel  110 . 
     A high-pressure seal  111  may be disposed between the lid and the pressure vessel  110  in order to prevent the pressurized liquid in the pressure vessel  110  from leaking to the outside. The high-pressure seal  111  may be implemented as any of various well-known types of high-pressure seals, so long as it is capable of being elastically deformed by the internal pressure of the pressure vessel  110  or deformed along an inclined surface when pressure is applied to the inclined surface, thereby ensuring improved airtightness. 
     The pressure vessel  110  may have a charging port and a discharging port in order to charge and discharge a pressurized liquid into and from the pressure vessel  110 . The charging port and the discharging port may be formed in the lid  115 . In the case in which the lid  115  is mounted to the lower portion of the pressure vessel  110  so as to open the same, no separate discharging port may be formed. 
     A pressurized liquid supply unit  120  may be connected to the charging port of the pressure vessel  110  so as to supply a pressurized liquid to the interior of the pressure vessel  110  at high pressure. 
     In this case, the pressurized liquid supply unit  120  may be implemented as a pump or a piston in order to supply the pressurized liquid at high pressure. 
     A metal wire may be wound around the pressure vessel  110  in order to increase the rigidity of the pressure vessel  110  so that the pressure vessel  110  withstands high pressure. The metal wire may be implemented as a piano wire. 
     When the pressure vessel  110  is reinforced by a metal wire, it is capable of withstanding extra-high pressure of 6000 bar or more, whereby it is possible to process a workpiece at extra-high pressure. 
     A thermal insulator  113  may be disposed in the pressure vessel  110  in order to prevent internal heat of the pressure vessel  110  from being dissipated to the outside or to prevent the inner temperature of the pressure vessel  110  from changing due to the exchange of heat with the outside. 
     The thermal insulator  113  may be disposed on the surface of the lid  115  of the pressure vessel  110  as well as in the pressure vessel  110 , thereby insulating the entire inner surface of the pressure vessel  110 . 
     The main purpose of the thermal insulator  113  is to maintain the temperature of the pressurized liquid, which is heated or cooled in the pressure vessel  110 , rather than to maintain the inner temperature of the pressure vessel  110 , thereby enabling efficient heating and cooling of a workpiece. 
     The pressurized liquid charged into the pressure vessel  110  to press the workpiece may be water or oil. 
     Here, if gas is used to press the workpiece, it takes a long time to press the workpiece because gas is more compressible than liquid, and it is difficult to store gas because gas occupies a greater volume than liquid. Further, in the event of leakage of gas, it is difficult to collect the leaked gas. Furthermore, it is not easy to handle gas. 
     In contrast, in the embodiment, a pressurized liquid is charged into the pressure vessel  110  in order to press a workpiece. Accordingly, the embodiment is advantageous from the aspects of storage, recovery in the event of leakage, and handling. 
     As shown in  FIG. 1 , the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention may include a tray  170 . 
     The tray  170  may accommodate a workpiece, and may be used to carry the workpiece into or out of the pressure vessel  110 . 
     The tray  170  may include a plurality of shelves  175  so that each of the workpieces is seated on a respective one of the shelves  175 . The workpieces may be carried into or out of the pressure vessel  110  in the state of being seated on the shelves  175 . 
     In addition to the function of carrying the workpiece into or out of the pressure vessel  110 , the tray  170  may function to form a circulation flow of the pressurized liquid in the pressure vessel  110 . 
     The tray  170  may include a tray wall  171 , which defines an inner space thereof in which the workpiece is placed. That is, the inner space of the tray  170  may be isolated from the inner space of the pressure vessel  110  by the tray wall  171 . The tray wall  171  may be formed in a cylindrical shape. 
     A door may be mounted to the tray wall  171  in order to open and close the same so that the workpiece is put into or taken out of the tray  170 . 
     The tray  170  may have inlet/outlet holes  173  formed in the upper and lower portions thereof to allow the pressurized liquid to be introduced into and discharged from the tray  170  so that the pressurized liquid passes through the inner space of the tray  170 . The inlet/outlet holes  173  may be formed so as to penetrate the upper and lower portions of the tray  170 , or may be formed in such a shape that the entire areas of the upper and lower portions of the tray  170  are open. 
     Each of the shelves  175  may have a plurality of shelf-holes formed therethrough to allow the pressurized liquid flowing through the inner space of the tray  170  to pass therethrough. 
     In the embodiment, the pressurized liquid flows into the tray  170  through the inlet/outlet hole  173  formed in the upper portion of the tray  170 , and flows out of the tray  170  through the inlet/outlet hole  173  formed in the lower portion of the tray  170 . The pressurized liquid that flows out of the tray  170  is moved upwards to the region above the tray  170  along the outer surface of the tray wall  171  by the pressurized liquid circulation fan  150 , and flows again into the tray  170  through the inlet/outlet hole  173  formed in the upper portion of the tray  170 . In this way, the pressurized liquid circulates in the tray  170 . 
     Alternatively, the pressurized liquid may circulate in the direction opposite the direction in the embodiment described above. That is, the pressurized liquid may flow into the tray  170  through the inlet/outlet hole  173  formed in the lower portion of the tray  170 , and may flow out of the tray  170  through the inlet/outlet hole  173  formed in the upper portion of the tray  170 , and the pressurized liquid that flows out of the tray  170  may be moved downwards along the outer surface of the tray wall  171 , and may flow again into the tray  170  through the inlet/outlet hole  173  formed in the lower portion of the tray  170 . 
     The tray  170  may be mounted to the lid  115  for sealing the pressure vessel  110 . Thus, when the lid  115  is removed from the pressure vessel  110 , the tray  170  may be drawn out of the pressure vessel  110 , and when the lid  115  seals the pressure vessel  110 , the tray  170  may be introduced into the pressure vessel  110 . 
     As shown in  FIGS. 1 and 2 , the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention may include a heat exchanger  130 . 
     The heat exchanger  130  may be disposed in the pressure vessel  110  in order to exchange heat with the pressurized liquid flowing through the pressure vessel  110 , thereby heating or cooling the pressurized liquid. 
     The heat exchanger  130  may be configured to circulate a heat exchange medium therein so as to exchange heat with the pressurized liquid, thereby heating and cooling the pressurized liquid. 
     The heat exchanger  130  may have a medium passage  135   b , through which the heat exchange medium passes to exchange heat with the pressurized liquid, and a circulation passage  135   a , through which the pressurized liquid passes to exchange heat with the heat exchange medium. 
     In the heat exchanger  130 , the medium passage  135   b  and the circulation passage  135   a  may be formed so as not to communicate with each other in order to prevent the heat exchange medium and the pressurized liquid from mixing with each other. 
     The heat exchanger  130  may be formed such that a plurality of thermally conductive plates  135  is stacked, and the plurality of thermally conductive plates  135  may be bonded to each other using a diffusion bonding method. 
     For example, the heat exchanger  130  may be manufactured in the manner of forming a circulation passage groove for forming the circulation passage  135   a  and a medium passage groove for forming the medium passage  135   b  in each of the thermally conductive plates  135 , layering the thermally conductive plates  135 , and bonding the thermally conductive plates  135  to each other. 
     Since the circulation passage  135   a  and the medium passage  135   b  formed in the thermally conductive plates  135  do not communicate with each other, the pressurized liquid and the heat exchange medium may move independently without mixing with each other. 
     The thermally conductive plates  135  may be bonded to each other using a diffusion bonding method, i.e. may be bonded to each other by being pressed by external force. 
     The heat exchanger  130  may include a central supply portion  131  and a seating supply portion  133 . 
     The central supply portion  131  may be formed in the center of the heat exchanger  130 , and may communicate with one end of the circulation passage  135   a.    
     The portion of the pressurized liquid circulation fan  150  that generates suction force for suctioning the pressurized liquid may be located in the central supply portion  131 , and the pressurized liquid that has been heated or cooled while passing through the circulation passage  135   a  may be supplied to the pressurized liquid circulation fan  150  by the suction force of the pressurized liquid circulation fan  150 . 
     The tray  170  may be seated on the seating supply portion  133 . In the state in which the tray  170  is seated on the seating supply portion  133 , the seating supply portion  133  may communicate with the region close to the inner circumference of the tray wall  171  and the other end of the circulation passage  135   a  so that the pressurized liquid that has exchanged heat with the workpiece in the tray  170  is introduced into the heat exchanger  130 . 
     When the tray  170  is seated on the seating supply portion  133 , the circumference of the lower end of the tray  170  may be brought into close contact with the seating supply portion  133 . The pressurized liquid may be moved from the other end of the circulation passage  135   a  to the one end of the circulation passage  135   a  by the suction force of the pressurized liquid circulation fan  150 , and at the same time may exchange heat with the heat exchange medium. Thereafter, the pressurized liquid suctioned by the pressurized liquid circulation fan  150  may be discharged to the outside of the tray  170 . 
     As shown in  FIG. 1 , the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention may include a heating/cooling supply unit  140 . 
     The heating/cooling supply unit  140  may heat or cool the heat exchange medium that is to be supplied to the heat exchanger  130  in order to heat or cool the heat exchanger  130 . 
     The heating/cooling supply unit  140  may include a heater  141  for heating the heat exchange medium and a cooler  143  for cooling the heat exchange medium. 
     For example, the heater  141  may be implemented as a heating element or a thermoelectric module, which is heated by application of electricity thereto. 
     For example, the cooler  143  may include a thermoelectric module, and the cooled surface of the thermoelectric module may cool the heat exchange medium. 
     As another embodiment, the cooler  143  may include a freezing cycle, i.e. a condenser, an evaporator, a compressor, and an expander, so that a phase-change material cools the evaporator via the freezing cycle and the heat exchange medium is cooled through heat exchange with the evaporator. 
     The heating/cooling supply unit  140  may include a medium circulation pump  145 . The heat exchange medium may be forcibly circulated through the heat exchanger  130 , the heater  141 , and the cooler  143  by the medium circulation pump  145  so as to be heated or cooled. 
     The heating/cooling supply unit  140  may selectively operate the heater  141  and the cooler  143  in order to heat or cool the pressurized liquid. 
     For example, when it is intended to heat the pressurized liquid, the heating/cooling supply unit  140  may stop operating the cooler  143  and may operate only the heater  141 , and when it is intended to cool the pressurized liquid, the heating/cooling supply unit  140  may stop operating the heater  141  and may operate only the cooler  143 . 
     The heater  141  and the cooler  143  may be connected in series, and the heating/cooling supply unit  140  may operate only one of the heater  141  and the cooler  143  in order to heat or cool the heat exchange medium. Alternatively, the heater  141  and the cooler  143  may be connected in parallel, and the heating/cooling supply unit  140  may perform control such that the heat exchange medium passes through only one of the heater  141  and the cooler  143  so as to be heated or cooled. 
     As shown in  FIG. 1 , the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention may include a pressurized liquid circulation fan  150  and a circulation fan motor  151 . 
     The pressurized liquid circulation fan  150  may include a plurality of vanes, which extend radially. The pressurized liquid circulation fan  150  may generate suction force and discharge force due to the centrifugal force that is generated during the rotation thereof. The pressurized liquid circulation fan  150  may be implemented as a centrifugal fan, which suctions a fluid in the axial direction thereof and discharges the fluid in the radial direction thereof. 
     Alternatively, the pressurized liquid circulation fan  150  may be implemented as any of various types of impellers, rather than a centrifugal fan, so long as it is capable of delivering a liquid. 
     The central portion of the pressurized liquid circulation fan  150 , at which suction force is generated, may be located in the central supply portion  131  of the heat exchanger  130  so as to suction the pressurized liquid through the central supply portion  131 . The suctioned pressurized liquid may be discharged to the outside of the heat exchanger  130  in the radial direction. 
     The circulation fan motor  151  may rotate the pressurized liquid circulation fan  150 . The circulation fan motor  151  may be implemented as an electric motor, which is rotated by application of electricity thereto. 
     In the case in which the circulation fan motor  151  is located in the pressure vessel  110 , the pressurized liquid, which is supplied to the pressure vessel  110 , may flow into the circulation fan motor  151 , leading to the occurrence of a short circuit in the circulation fan motor  151 . 
     Therefore, the circulation fan motor  151  may be accommodated in a motor accommodation unit  160 , which will be described below. 
     As shown in  FIGS. 1 and 3 , the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention may include a motor accommodation unit  160  and a pressure equalization adjustment unit  165 . 
     The motor accommodation unit  160  may have therein a space formed so as to be isolated from the space in the pressure vessel  110  into which the pressurized liquid is charged. The circulation fan motor  151  may be accommodated in the motor accommodation unit  160 . 
     The motor shaft of the circulation fan motor  151  accommodated in the motor accommodation unit  160  may penetrate the pressure vessel  110  and may be coupled to the pressurized liquid circulation fan  150  located in the pressure vessel  110 . A shaft seal  153  may be mounted in the portion of the pressure vessel  110  through which the motor shaft passes in order to prevent the pressurized liquid from being introduced into the motor accommodation unit  160 . 
     The motor accommodation unit  160  may be filled with an insulating liquid. The insulating liquid, which is insulative, may prevent the occurrence of a short circuit in the circulation fan motor  151  due to the electricity supplied to the circulation fan motor  151 . 
     In the state in which the motor accommodation unit  160  is filled with the insulating liquid, the circulation fan motor  151  may be placed in the motor accommodation unit  160  so as to be immersed in the insulating liquid. 
     The insulating liquid may be a liquid having compressibility equal to or lower than that of the pressurized liquid charged in the pressure vessel  110 . For example, the insulating liquid may be a non-curable liquid. 
     The pressure equalization adjustment unit  165  may increase or reduce the pressure in the motor accommodation unit  160  in proportion to changes in the internal pressure of the pressure vessel  110  so that the internal pressure of the pressure vessel  110  and the internal pressure of the motor accommodation unit  160  become identical or the difference therebetween is minimized. 
     The pressure equalization adjustment unit  165  may be mounted in the portion through which the motor accommodation unit  160  and the pressure vessel  110  communicate with each other. Since the pressure equalization adjustment unit  165  reduces the difference in pressure between the pressure vessel  110  and the motor accommodation unit  160 , damage to the shaft seal  153  due to the pressure difference may be minimized, whereby the pressurized liquid may be prevented from flowing into the motor accommodation unit  160 , thus minimizing damage to the circulation fan motor  151 . 
     The pressure equalization adjustment unit  165  may include a pressure chamber  166 , which is formed in a portion of the motor accommodation unit  160  so as to communicate with the pressure vessel  110 . Alternatively, the pressure chamber  166  may be formed at a position spaced apart from the motor accommodation unit  160 , and may communicate with the motor accommodation unit  160  through a communication passage. 
     The pressure equalization adjustment unit  165  may include a bellows member  167 . 
     The bellows member  167  may be increased or reduced in volume by the pressurized liquid that is charged into the pressure vessel  110 , thereby pressurizing or depressurizing the insulating liquid in the motor accommodation unit  160 . In this way, the bellows member  167  may increase or reduce the pressure in the motor accommodation unit  160 . 
     The bellows member  167  may be mounted in the pressure chamber  166  so as to be expanded or contracted in a direction oriented toward the motor accommodation unit  160 . 
     The bellows member  167  may have one open end and one closed end. The bellows member  167  may be mounted in the pressure chamber  166  such that the open end thereof is oriented toward the pressure vessel  110  and the closed end thereof is oriented toward the motor accommodation unit  160 . 
     When the pressurized liquid in the pressure vessel  110  enters the bellows member  167  through the open end thereof, the bellows member  167  may expand. In the expanded state, when the pressurized liquid escapes from the bellows member  167 , the bellows member  167  may contract, i.e. may be elastically restored to the original shape thereof. 
     The bellows member  167  may be made of metal so as to withstand the high pressure of the pressurized liquid that is charged into the pressure vessel  110 . 
     In order to allow a fluid to enter the bellows member  167 , the bellows member  167  may be formed in a manner such that multiple ring-shaped metal plates are stacked and the inner circumferences of neighboring plates and the outer circumferences of neighboring plates are alternately bonded. 
     For example, the bellows member  167  may be manufactured as follows: in the state in which multiple ring-shaped plates are stacked, the inner circumferences of the first and second neighboring plates are bonded to each other, the outer circumference of the third plate, which is disposed on the second plate, is bonded to the outer circumference of the second plate, and the inner circumference of the fourth plate, which is disposed on the third plate, is bonded to the inner circumference of the third plate. The embodiment is not limited to any specific number of ring-shaped metal plates. 
     Subsequently, a closed plate may be bonded to one of the two opposite ends of the bellows member  167 , whereby one end of the bellows member  167  may be open, and the other end thereof may be closed. 
     When the bellows member  167  is expanded in the pressure chamber  166  by the pressure in the pressure vessel  110  and thus occupies a larger space in the pressure chamber  166 , the bellows member  167  may pressurize the insulating liquid present in the pressure chamber  166 , thereby increasing the pressure in the motor accommodation unit  160 . 
     On the other hand, in the expanded state of the bellows member  167 , when the pressure in the pressure vessel  110  is lowered, the pressurized liquid that has entered the bellows member  167  may be moved back to the pressure vessel  110  by the pressure in the pressure chamber  166 , and accordingly, the bellows member  167  may contract. 
     The operation and effects of the components described above will be described below. 
     In the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention, the heat exchanger  130  for heating or cooling the pressurized liquid and the thermal insulator  113  for maintaining the temperature of the heated or cooled pressurized liquid may be mounted in the pressure vessel  110 . 
     The pressurized liquid may be supplied to the interior of the pressure vessel  110  at high pressure, so a workpiece received in the pressure vessel  110  may be processed by the pressure of the pressurized liquid. The pressurized liquid may be supplied to the interior of the pressure vessel  110 , and may be discharged to the outside of the pressure vessel  110  through the charging port and the discharging port formed in the pressure vessel  110 . 
     The pressurized liquid may be supplied to the interior of the pressure vessel  110  at high pressure by the pressurized liquid supply unit  120 . 
     In the heat exchanger  130 , the heat exchange medium may pass through the medium passage  135   b , which does not communicate with the circulation passage  135   a , and the pressurized liquid may exchange heat with the heat exchange medium so as to be heated or cooled while passing through the circulation passage  135   a.    
     In the heat exchanger  130 , the pressurized liquid that has been heated or cooled in the circulation passage  135   a  may flow into the central supply portion  131 , which communicates with one end of the circulation passage  135   a.    
     The tray  170  may be seated on the seating supply portion  133  of the heat exchanger  130 . The seating supply portion  133  may communicate with the region close to the inner circumference of the tray  170  and the other end of the circulation passage  135   a  so that the pressurized liquid in the tray  170  is introduced into the circulation passage  135   a  of the heat exchanger  130 . 
     The thermally conductive plates  135 , which constitute the heat exchanger  130 , may be stacked and diffusion bonded to each other in order to withstand high pressure. 
     In the state in which the tray  170  is seated on the seating supply portion  133 , a workpiece may be placed on each of the shelves  175  of the tray  170 , which are arranged in a multi-stage structure. The pressurized liquid introduced into the tray  170  may pass through the plurality of shelf-holes formed through the shelves  175 . 
     The pressurized liquid may pass through the tray  170  from the top to the bottom through the inlet/outlet holes  173  formed in the upper and lower portions of the tray  170 . While passing through the tray  170 , the pressurized liquid may press the workpiece, and may exchange heat with the workpiece so as to heat or cool the same. The tray wall  171  of the tray  170  may partition the space in the pressure vessel  110  into space in which the workpiece is placed and a passage through which the pressurized liquid flows. 
     Since the tray  170  is coupled to the lid  115 , when the lid  115  is removed from the pressure vessel  110 , the tray  170  may be drawn out of the pressure vessel  110 , and when the lid  115  covers the pressure vessel  110 , the tray  170  may be introduced into the pressure vessel  110 . 
     The heating/cooling supply unit  140  may be connected to the heat exchanger  130  in order to supply a heat exchange medium to the heat exchanger  130 . The heating/cooling supply unit  140  may heat the heat exchange medium using the heater  141 , or may cool the heat exchange medium using the cooler  143 , and may supply the heated or cooled heat exchange medium to the heat exchanger  130 . 
     The pressurized liquid circulation fan  150  for circulating the pressurized liquid may be disposed in the central supply portion  131  of the heat exchanger  130 . The pressurized liquid circulation fan  150  may be rotated by the circulation fan motor  151 , thereby suctioning the pressurized liquid from the central supply portion  131  and discharging the pressurized liquid to the outside in the radial direction. 
     The circulation fan motor  151  may be disposed in the motor accommodation unit  160 , which is isolated from the pressure vessel  110 . An insulating liquid may be charged into the motor accommodation unit  160  so that the circulation fan motor  151  is immersed in the insulating liquid. 
     The pressure equalization adjustment unit  165  may be mounted in the motor accommodation unit  160  in order to prevent damage to the shaft seal  153 , which seals the circulation fan motor  151 , due to the difference in the pressure between the pressure vessel  110  and the motor accommodation unit  160 . 
     The pressure chamber  166  of the pressure equalization adjustment unit  165  may allow the motor accommodation unit  160  and the internal space in the pressure vessel  110  to communicate with each other, and the bellows member  167  may be mounted in the pressure chamber  166  so as to be expanded or contracted by the pressure in the pressure vessel  110 . 
     As the bellows member  167  mounted in the pressure chamber  166  is expanded or contracted in a direction oriented toward the motor accommodation unit  160 , the bellows member  167  may pressurize or depressurize the insulating liquid in the motor accommodation unit  160 . In this way, the bellows member  167  may increase or reduce the internal pressure in the motor accommodation unit  160  so as to match the internal pressure in the pressure vessel  110 . 
     The bellows member  167  may be made of metal so as to minimize corrosion and withstand high pressure. The bellows member  167  may be formed in a manner such that multiple ring-shaped metal plates are stacked and the outer circumferences of neighboring plates and the inner circumferences of neighboring plates are alternately bonded. 
     In the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention described above, the lid  115  of the pressure vessel  110  is opened, and a workpiece is placed on the shelf  175  of the tray  170 . 
     Subsequently, the lid  115  is put on the pressure vessel  110  in order to seal the pressure vessel  110  and to put the tray  170  into the pressure vessel  110 . In the state in which the pressure vessel  110  is sealed by the lid  115 , a pressurized liquid is injected into the pressure vessel  110  by the pressurized liquid supply unit  120 . 
     The pressurized liquid is injected into the pressure vessel  110  in order to maintain a predetermined pressure at which to press the workpiece. The workpiece is processed by the pressure applied thereto by the pressurized liquid at a predetermined pressure for a predetermined time period. 
     In order to heat or cool the workpiece when processing the same, the heating/cooling supply unit  140  selectively operates the heater  141  or the cooler  143 . 
     When the heater  141  is operated, the heat exchange medium is heated by the heater  141 , and the heated heat exchange medium is supplied to the heat exchanger  130 . When the cooler  143  is operated, the heat exchange medium is cooled by the cooler  143 , and the cooled heat exchange medium is supplied to the heat exchanger  130 . 
     The heated or cooled heat exchange medium supplied to the heat exchanger  130  passes through the medium passage  135   b , and the pressurized liquid passes through the circulation passage  135   a  of the heat exchanger  130 , and at the same time exchanges heat with the heated or cooled heat exchange medium so as to be heated or cooled. The heated or cooled pressurized liquid heats or cools the workpiece to be processed. 
     The pressurized liquid, heated or cooled by the heat exchanger  130 , is circulated in the pressure vessel  110  by the pressurized liquid circulation fan  150 , thereby rapidly changing the temperature in the pressure vessel  110  and uniformly maintaining the new temperature. 
     When the pressurized liquid circulation fan  150  rotates, suction force is generated in the central supply portion  131  of the heat exchanger  130 . Thereby, the pressurized liquid is suctioned into the other end of the circulation passage  135   a  of the heat exchanger  130  via the seating supply portion  133  of the heat exchanger  130 , and is heated or cooled through heat exchange with the heat exchange medium in the heat exchanger  130 . The heated or cooled pressurized liquid is supplied to the central supply unit  131 , which communicates with the one end of the circulation passage  135   a.    
     As the pressurized liquid is suctioned into the seating supply portion  133 , which communicates with the other end of the circulation passage  135   a , the pressurized liquid is introduced into the tray  170  through the inlet/outlet hole  173  formed in the upper portion of the tray wall  171 . The pressurized liquid introduced into the tray  170  comes into contact with the workpiece, thereby pressing the workpiece while heating or cooling the same. 
     The pressurized liquid that has heated or cooled the workpiece is discharged through the inlet/outlet hole  173  formed in the lower portion of the tray  170 , and is introduced into the other end of the circulation passage  135   a  via the seating supply portion  133 . The pressurized liquid discharged from the pressurized liquid circulation fan  150  is moved upwards along the outer surface of the tray wall  171 , and is introduced into the tray  170  through the inlet/outlet hole  173  formed in the upper portion of the tray  170 . 
     That is, the pressurized liquid heated or cooled by the heat exchanger  130  is discharged to the space between the tray wall  171  and the pressure vessel  110  by the pressurized liquid circulation fan  150 , and is moved to the top of the pressure vessel  110 . Subsequently, the pressured liquid is introduced into the tray  170  through the inlet/outlet hole  173  formed in the upper portion of the tray  170 , and presses and heats or cools the workpiece while passing through the interior of the tray  170 . 
     The pressurized liquid that has heated or cooled the workpiece is supplied to the central supply portion  131  via the seating supply portion  133  of the heat exchanger  130 , and is suctioned into the pressurized liquid circulation fan  150 . Subsequently, the pressurized liquid is discharged from the pressurized liquid circulation fan  150  in the radial direction, and is moved to the space between the tray wall  171  and the pressure vessel  110 . 
     The embodiment has been described as being configured such that the pressurized liquid that has passed through the heat exchanger  130  is moved upwards through the space between the tray wall  171  and the pressure vessel  110  and returns back to the heat exchanger  130  via the interior of the tray  170 . 
     Alternatively, another embodiment may be configured such that the pressurized liquid discharged from the pressurized liquid circulation fan  150  is introduced into the tray  170  via the heat exchanger  130 , exchanges heat with the workpiece, is discharged through the inlet/outlet hole  173  formed in the upper portion of the tray  170 , is moved downwards through the space between the pressure vessel  110  and the tray wall  171 , and is introduced again into the tray  170  via the heat exchanger  130  by the pressurized liquid circulation fan  150 . 
     In this way, since the pressurized liquid is circulated by the pressurized liquid circulation fan  150 , the pressurized liquid is capable of being rapidly heated or cooled by the heat exchanger  130 . According, it is possible to rapidly heat or cool the workpiece, thereby rapidly processing the workpiece. 
     For example, when withdrawing the heated workpiece, it is required to cool the workpiece before withdrawing the same in order to prevent burning and to minimize deformation of the workpiece. According to the embodiment, the cooler  143  is operated in order to cool the heat exchanger  130 , thereby shortening the time taken to cool the pressurized liquid, thus enabling rapid withdrawal of the workpiece. 
     Further, since the heat exchanger  130  is heated or cooled by the heating/cooling supply unit  140 , it is possible to rapidly cool a workpiece that has been heated to a high temperature so as to realize, for example, quenching or to rapidly heat a workpiece that has been cooled to a low temperature. 
     Furthermore, since a workpiece heated to a high temperature is capable of being rapidly cooled, it is possible to prevent a springback phenomenon, which frequently occurs in a workpiece heated to a high temperature. 
     Meanwhile, when the pressure in the pressure vessel  110  is increased by the pressurized liquid, the bellows member  167  of the pressure equalization adjustment unit  165  expands and pressurizes the insulating liquid in the pressure chamber  166 . As a result, the pressure in the motor accommodation unit  160  is also increased. 
     On the other hand, when the pressure in the pressure vessel  110  is lowered, the bellows member  167 , which is in an expanded state, contracts and depressurizes the insulating liquid in the pressure chamber  166 . As a result, the pressure in the motor accommodation unit  160  is also lowered. 
     In this way, since the pressure equalization adjustment unit  165  equalizes the pressure in the motor accommodation unit  160  with the pressure in the pressure vessel  110 , it is possible to prevent damage to the shaft seal  153 , which seals the motor shaft, due to the pressure difference, thus preventing the occurrence of a short circuit in the circulation fan motor  151  due to the introduction of the pressurized liquid into the motor accommodation unit  160 . 
     As described above, since the isostatic press apparatus  100  enabling rapid heating and cooling using the pressurized liquid circulation fan  150  according to the embodiment of the present invention is capable of rapidly heating or cooling the pressurized liquid by circulating the pressurized liquid using the pressurized liquid circulation fan  150 , it is possible to rapidly achieve a processing task, to minimize the occurrence of processing defects in the workpiece by maintaining the temperature of the workpiece uniform for a long time, and to prevent the occurrence of a springback phenomenon, in which at least a portion of the workpiece returns to the original shape thereof. 
     In addition, since the pressure equalization adjustment unit  165  increases or decreases the pressure in the motor accommodation unit  160  so as to match the pressure in the pressure vessel  110 , it is possible to prevent damage to the shaft seal  153  due to a pressure difference, thus preventing damage to the circulation fan motor  151  due to the introduction of the pressurized liquid into the motor accommodation unit  160 . 
     In addition, since the bellows member  167  for adjusting the pressure of the pressure equalization adjustment unit  165  is made of metal, it is possible to minimize damage thereto when the pressure greatly changes. In addition, since the heat exchanger  130  is manufactured in a manner of stacking multiple thermally conductive plates  135 , it is possible to prevent the heat exchanger  130  from being damaged by the pressure in the pressure vessel  110 . 
     In addition, since the pressurized liquid that has passed through the tray  170  is introduced into the circulation passage  135   a , it is possible to minimize the occurrence of turbulence during circulation of the pressurized liquid, thereby rapidly heating or cooling the pressurized liquid and maintaining a uniform temperature throughout the entire internal space of the pressure vessel  110 . 
     As is apparent from the above description, according to the present invention, since a heat exchanger is heated or cooled by a heating/cooling supply unit, it is possible to provide a warm isostatic press (WIP) apparatus enabling a rapid change in temperature and to rapidly cool a high-temperature liquid pressurized to a high pressure, thereby shortening the processing time and enabling manufacture of a high-quality product, which has no pores and is less likely to spring back. 
     In addition, since a pressurized liquid circulation fan circulates the pressurized liquid and a tray forms a circulation flow of the pressurized liquid in a pressure vessel, it is possible to maintain the temperature of the pressurized liquid uniform for a long time and to rapidly change the temperature of the pressurized liquid, thereby enabling tasks requiring rapid processing and minimizing defects in a workpiece. 
     In addition, because a circulation fan motor is mounted in a motor accommodation unit that is isolated from a pressure vessel and a pressure equalization adjustment unit is mounted in the motor accommodation unit in order to adjust the pressure in the motor accommodation unit to match the pressure in the pressure vessel, it is possible to prevent damage to a shaft seal, thus preventing damage to the circulation fan motor due to the introduction of pressurized liquid into the motor accommodation unit. 
     Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
         
           
               100 : isostatic press apparatus enabling rapid heating and cooling using pressurized liquid circulation fan 
               110 : pressure vessel 
               111 : high-pressure seal 
               113 : thermal insulator 
               115 : lid 
               120 : pressurized liquid supply unit 
               130 : heat exchanger 
               131 : central supply portion 
               133 : seating supply portion 
               135 : thermally conductive plate 
               135   a : circulation passage 
               135   b : medium passage 
               140 : heating/cooling supply unit 
               141 : heater 
               143 : cooler 
               145 : medium circulation pump 
               150 : pressurized liquid circulation fan 
               151 : circulation fan motor 
               153 : shaft seal 
               160 : motor accommodation unit 
               165 : pressure equalization adjustment unit 
               166 : pressure chamber 
               167 : bellows member 
               170 : tray 
               171 : tray wall 
               173 : inlet/outlet hole 
               175 : shelf