Patent Publication Number: US-2021186250-A1

Title: Cooking apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0170125, filed on Dec. 18, 2019, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a cooking apparatus that forcibly injects water into a cooking space to generate a pressure and that performs a high-temperature cooking operation under the generated pressure. 
     BACKGROUND 
     A pressure cooker may heat an object subject to cooking and water stored in a sealed inner space (e.g., an internal pot) together to evaporate the water. For example, when the water is evaporated in the inner space, a pressure in the inner space may be increased, and a boiling point of water may be also increased. When the boiling point is increased, the pressure cooker may cook the object in the inner space to a higher temperature. Using the method, the object may be cooked at a high temperature. 
       FIG. 1  is a view illustrating an example of a boiling point of water changing based on a gauge pressure. A cooking operation of the pressure cooker of the related art is described with reference to  FIG. 1 . 
     For example, the pressure cooker of the related art may heat an object and water stored in the inner space together under atmospheric pressure (a gauge pressure of 0 kPa). When a temperature of the heated water reaches 100 degrees Celsius, the water may be evaporated, an air pressure in the inner space is gradually increased to about 2 atm (a gauge pressure of about 101 kPa), and a boiling point of the water in the inner space may be increased to about 120 degrees Celsius. Due to the increased boiling point, the pressure cooker may heat the object in the inner space to about 120 degrees Celsius, and the object may be heated and cooked at a high temperature of about 120 degrees Celsius. 
     As described above, in the pressure cooker of the related art, steam generated through the heating of water may be used as a means to create a pressure for raising a boiling point of water. That is, in the pressure cooker of the related art, as a pressure is generated only after water is evaporated, the object may not be cooked at a high temperature from the beginning. Thus, it may take a long time to cook the object. 
     In some cases, a cooking apparatus may create a pressure in a cooking space using an additional pressure booster. 
       FIGS. 2A and 2B  illustrate a cooking apparatus of the related art that includes a lid  20  that opens and closes a cooking cavity  11  and a pressure booster  30  installed in the lid  20 . 
     The pressure booster  30  may communicate with an intake port  23 , and air outside of the cooking cavity  11  may be suctioned into the cooking cavity  11  through the intake port  23  by the pressure booster  30 , and may increase an air pressure of the cooking cavity  11 . 
     In some cases, gas may be used as a means to generate a pressure in the cooking space. Since gas has high compressibility, and it may take a long time to generate a pressure in the cooking space using gas. 
     In some cases, where gas has high expandability, and a sufficient pressure may not be generated in the cooking space for safety reasons. For instance, referring to  FIG. 2A , external air is suctioned and compressed to create a pressure in the cooking cavity  11 . As the pressure in the cooking cavity  11  is increased, expandability of compressed air is increased. In some cases, the lid  20  may be exploded. 
     In some cases, where steam is generated through evaporation of water, a user may have difficulty in finding an amount of water to be evaporated in the cooking space. The user may learn how to adjust an amount of water to be stored together with an object by trial and error in which the quality of a cooked object may not be ensured. 
     SUMMARY 
     The present disclosure is directed to a cooking apparatus that may perform a cooking operation under a high-pressure environment that is created by forcibly supplying water. 
     The present disclosure is also directed to a cooking apparatus that may adjust a moisture content of an object subject to cooking. 
     The present disclosure is also directed to a cooking apparatus that may condense steam discharged after a cooking operation. 
     Aspects of the present disclosure are not limited to the above-described ones. Additionally, other aspects and advantages that have not been mentioned may be clearly understood from the following description and may be more clearly understood from implementations. Further, it will be understood that the aspects and advantages of the present disclosure may be realized via means and combinations thereof that are described in the appended claims. 
     According to one aspect of the subject matter described in this application, a cooking apparatus includes a chamber, a heater configured to heat the chamber, a pump configured to supply water into the chamber to thereby generate a pressure in the chamber, and a processor configured to control at least one of the heater or the pump based on a temperature of the chamber and the pressure in the chamber. 
     Implementations according to this aspect may include one or more of the following features. For example, the cooking apparatus may further include a lid that may be configured to open and close the chamber. In some implementations, the heater may include a coil disposed at an outer surface of the chamber and configured to heat the chamber through a magnetic field generated in the coil. 
     In some implementations, the pump may be configured to supply additional water into the chamber that is filled with water to thereby generate the pressure in the chamber. For instance, the pump may forcibly supply water into the chamber after the chamber is filled with water to a predetermined full level of the chamber. 
     In some implementations, the cooking apparatus may further include a countercurrent prevention valve that is disposed between the pump and the chamber and that may be configured to restrict backflow of water from the chamber to the pump. In some implementations, the cooking apparatus may further include a pressure sensor that is disposed in a flow path between the pump and the chamber and that may be configured to sense the pressure in the chamber. 
     In some implementations, the cooking apparatus may further include a temperature sensor that is disposed at an outer surface of the chamber and that may be configured to sense the temperature of the chamber. In some implementations, the cooking apparatus may further include a pressure release valve that may be configured to release the pressure generated in the chamber. In some examples, the processor may be configured to control the pump to supply water into the chamber in a state in which the pressure release valve is opened, and block the pressure release valve based on the chamber being filled with water to a full level. 
     In some examples, the processor may be configured to control a degree to which the pressure release valve is opened. In some examples, the cooking apparatus may further include a gas-liquid separator that may be configured to separate water and steam discharged through the pressure release valve. In some examples, the cooking apparatus may further include a condenser that may be configured to condense steam discharged through the pressure release valve. 
     In some implementations, the processor may be configured to control the pump to supply water into the chamber until the pressure in the chamber reaches a predetermined pressure. In some implementations, the processor may be configured to control the heater to increase the temperature of the chamber to a predetermined temperature. In some implementations, the processor may be configured to control the heater to increase the temperature of the chamber a target temperature that is lower than a boiling point corresponding to the pressure in the chamber. 
     In some implementations, the processor may be configured to control the pump to supply water into the chamber until the pressure in the chamber reaches a predetermined pressure, and then control the heater to increase the temperature of the chamber to a target temperature that is lower than a boiling point corresponding to the predetermined pressure. In some examples, the processor may be configured to maintain the pressure in the chamber at the predetermined pressure while controlling the heater to increase the temperature of the chamber to the target temperature. 
     In some implementations, the cooking apparatus may further include a pressure release valve that may be configured to release the pressure generated in the chamber, and the processor may be configured to, based on the temperature of the chamber corresponding to the target temperature, open at least a portion of the pressure release valve to a predetermined degree to thereby evaporate at least a portion of pressurized water in the chamber. 
     In some implementations, the processor may be configured to control the pump to supply water into the chamber to increase the pressure in the chamber to a predetermined pressure while controlling the heater to increase the temperature of the chamber to a target temperature that is lower than a boiling point corresponding to the pressure in the chamber. 
     In some examples, the cooking apparatus may further include a pressure release valve that may be configured to release the pressure generated in the chamber, where the processor may be configured to, based on the temperature of the chamber corresponding to the target temperature, open at least a portion of the pressure release valve to a predetermined degree to thereby evaporate at least a portion of pressurized water in the chamber. 
     In some implementations, the cooking apparatus may heat a chamber and performs an operation of cooking an object after a high pressure is generated in the chamber by forcibly injecting water into the chamber where the object is stored. 
     In some implementations, the cooking apparatus may adjust a moisture content of an object by controlling a speed at which high-temperature high-pressure water filling a chamber is discharged. 
     In some implementations, the cooking apparatus may condense steam into water again when high-temperature high-pressure water filling a chamber is turned into the steam. 
     In some implementations, the cooking apparatus may perform a cooking operation in a high-pressure environment that is created by forcibly supplying water, thereby making it possible to create a high-pressure environment rapidly in order to shorten a cooking period and to heat an object to a high temperature in order to ensure quality cooking for the object. 
     In some implementations, it may be possible to ease the cumbersome process of adjusting an amount of water previously for a cooking operation and to guarantee quality cooking to meet the taste of the user. 
     In some implementations, the cooking apparatus may condense steam that is discharged after a cooking operation, thereby reducing noise caused by the discharge of steam after the cooking operation and helping to prevent danger caused by the discharge of high-temperature steam. 
     Detailed effects of the present disclosure are described together with the above-described effects in the detailed description of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view illustrating an example of a boiling point of water changing based on a gauge pressure in related art. 
         FIG. 2A  and  FIG. 2B  are views illustrating an example of a pressure cooker in related art. 
         FIG. 3  is a block diagram illustrating example components of an example of a cooling apparatus. 
         FIG. 4  is a view illustrating an example of a cooking apparatus. 
         FIG. 5  is a view illustrating an example of a change in temperatures and pressures during an example cooking process. 
         FIG. 6  is a view illustrating an example of a change in temperatures and pressures during an example cooking process. 
     
    
    
     DETAILED DESCRIPTION 
     The above-described aspects, features and advantages are specifically described with reference to the accompanying drawings hereunder such that one having ordinary skill in the art to which the present disclosure pertains may easily implement the technical spirit of the disclosure. Below, one or more implementations of the present disclosure are specifically described with reference to the accompanying drawings. Throughout the drawings, identical reference numerals denote identical or similar components. 
     The present disclosure relates to a cooking apparatus that forcibly injects water into a cooking space to create a pressure and performs a high-temperature cooking operation under the created pressure. 
     Below, an example of a cooking apparatus is described with reference to  FIGS. 3 to 5 . 
       FIG. 3  is a block diagram illustrating example components of an example cooling apparatus, and  FIG. 4  is a view illustrating an example cooking apparatus. 
       FIGS. 5 and 6  are views illustrating examples of a change in temperatures and pressures during example cooking processes. 
     In some implementations, referring to  FIGS. 3 and 4 , a cooking apparatus  100  may include a chamber  110 , a heater  120 , a pump  130 , a pressure release valve  140 , a countercurrent prevention valve  150 , a sensor  160 , a gas-liquid separator  170 , a condenser  180 , and a processor  190 . The cooking apparatus  100  illustrated in  FIGS. 3 and 4  is provided according to an implementation, and components of the cooking apparatus  100  are not limited to those of the implementation in  FIGS. 3 and 4 . When necessary, some components may be added, modified or removed. 
     In some implementations, the cooking apparatus  100  may further include a memory that is implemented as a read-only memory (ROM), a random access memory (RAM), an erasable programmable read-only memory (EPROM), a flash drive, a hard drive and the like. In the memory, programs for operations of the processor  190  and various data for entire operations of the cooking apparatus  100  may be stored. The memory may be a non-transitory memory device. 
     The chamber  110  may be implemented as a hollow shape having an inner space. For example, the chamber  110  may have a hollow cylinder shape or may have a hollow polygonal prism shape. An object such as grain and the like may be stored in the inner space of the chamber  110 , and the object may be cooked in the inner space of the chamber  110 . For instance, the chamber  110  may be a pot of the cooking apparatus  100 . 
     The chamber  110  may further include a lid  110   a . The lid  110   a  may be configured to be open and close the chamber  110  and connected to one end of the chamber  110  to shield the inner space of the chamber  110  from the outside. For instance, when the lid  110   a  is opened, an object (e.g., grains, meats, and other types of food) subject to cooking may be received in the inner space of the chamber  110 , and the object in the chamber  110  may be cooked with the lid  110   a  closed. 
     The object in the chamber  110  may be cooked through a heating process. For example, the cooking apparatus  100  may include a heater  120  to heat the object. 
     The heater  120  may heat the chamber  110  and, the heated chamber  110  may deliver heat to the object therein. The heater  120  may include a heat source  122 , and a heating controller  121  for controlling the heat source  122 . 
     The heat source  122  may be implemented in various different forms. For example, the heat source  122  may be implemented as a gas burner that produces a flame or may be implemented as a coil  122  that generates a magnetic field. In addition, the heat source  122  may be implemented in various different forms that may heat the chamber  110 . Below, a heat source  122  implemented as a coil  122  is described for convenience of description. 
     The heater  120  may include a coil  122  provided on an outer surface of the chamber  110 , and may heat the chamber  110  through a magnetic field generated in the coil  122 . Referring back to  FIG. 4 , the coil  122  may be configured to turn and wrap around the outer surface of the chamber  110  a plurality of times. One end and the other end of the coil  122  may be electrically connected to the heating controller  121 , and the heating controller  121  may supply electric currents to the coil  122  to heat the chamber  110 . 
     In some examples, the heating controller  121  in the heater  120  may supply electric currents to the coil  122 . By doing so, a magnetic field may be generated in the coil  122 . The magnetic field generated in the coil  122  may induce electric currents to the chamber  110 , and the electric currents induced to the chamber  110  may generate Joule&#39;s heat to heat the chamber  110 . The operation of supplying electric currents performed by the heating controller  121  may be controlled by a processor  190 . Description in relation to this is provided hereunder. 
     For generation of induced currents, the chamber  110  may include any material having magnetic properties. The chamber  110 , for example, may include cast iron including iron (Fe), or clad in which iron (Fe), aluminum (Al), and stainless steel and the like are welded. 
     In some examples, cooking performance may be improved when an object is heated at a high temperature in a state where the object contains water. In some cases, when the object is heated at a high temperature, water contained in the object may be evaporated, and a moisture content of the object may be decreased. Accordingly, a temperature at which an object is heated may be controlled to a temperature lower than a boiling point of water. 
     As described above with reference to  FIG. 1 , a boiling point of water increases based on an increase in pressure. Accordingly, to heat an object at a high temperature, a pressure in a space where the object is stored needs to be increased. The cooking apparatus  100  of the present disclosure may include a pump  130  to increase the pressure. 
     For instance, the pump  130  may supply water into the chamber  110  to generate a pressure in the chamber  110 . Specifically, one end of the pump  130  may be connected to an external water supply  300 , and the other end may be connected to an inside of the chamber  110  to supply water supplied by the external water supply  300  into the chamber  110 . 
     A pressure in the chamber  110  may be generated only by water supplied by the pump  130 . In some examples, the operation of supplying water by the pump  130  may performed in a state in which the inner space of the chamber  110  is sealed and the chamber  110  is full of water. For example, the pump  130  may be configured to supply additional water into the chamber that is filled with water to a predetermined full level of water in the chamber. 
     The inner space of the chamber  110  may be filled with an object and air before the pump  130  supplies water into the chamber. When water starts to be supplied to the chamber in a state where the chamber  110  is not sealed (e.g., when the above-described lid  110   a  is opened), the air filling the inner space of the chamber  110  may be discharged from the chamber  110 , and the inner space of the chamber  110  may be filled with water. 
     When the inner space of the chamber  110  is full of water, the lid  110   a  of the chamber  110  may be closed, and the pump  130  may forcibly supply water to the inner space of the chamber  110  that has already been filled with water. By the water that is forcibly supplied to the chamber, a pressure in the chamber  110  may be increased. An increased amount of the pressure may be determined based on an amount of forcibly supplied water. 
     The cooking apparatus  100  may include a countercurrent prevention valve  150  between the pump  130  and the chamber  110  to help to prevent water from leaking from the inside of the chamber  110  towards the pump  130  due to an increase in pressures in the chamber  110 . 
     The countercurrent prevention valve  150  may be provided on a flow path that connects the pump  130  and the chamber  110 , and may help to prevent the water in the chamber  110  from flowing backwards to the pump  130 . The countercurrent prevention valve  150  may be implemented as various forms of valves that are used in the art to which the disclosure pertains. For example, the countercurrent prevention valve  150  may be a check valve that allows flow in one direction and that restricts flow in another direction. 
     The above-described method by which water is forcibly injected to create a pressure in the chamber  110  may generate a higher pressure more rapidly than a method of the related art by which steam is used to create a pressure. When a high pressure is generated in the chamber  110 , a boiling point of water that fills the chamber  110  is increased, and a temperature at which an object is heated may also be increased. Accordingly, cooking performance may be improved. 
     Referring to the related art shown in  FIG. 1 , a pressure in a space, where cooking is performed using steam, may be increased to approximately 2 atm (a gauge pressure of 101 kPa), and then an object is cooked. Accordingly, a temperature, at which the object may be cooked, may be limited to about 120 degrees Celsius that is a boiling point of water based on a pressure of 2 atm. Due to the temperature limitations, a cooking period becomes longer, and the quality of a cooked object may be deteriorated. 
     According to the present disclosure, water rather than steam is used to easily increase a pressure in the chamber  110  to 9 atm. Accordingly, a temperature, at which an object may be cooked, may be increased to about 175 degrees Celsius that is a boiling point of water based on 9 atm. Because of an increase in the heating temperature, an object may be rapidly cooked and the quality of the cooked object may be improved. 
     For the high-temperature high-pressure cooking operation, the processor  190  may control at least one of the above-described heater  120  and the pump  130  based on a temperature of the chamber  110  and a pressure in the chamber  110 . 
     In some implementations, operations of the heater  120  and the pump  130  may be controlled by the processor  190 , and the processor  190  may control the heater  120  and the pump  130  based on the current temperature of the chamber  110  and the current pressure generated in the chamber  110 . To this end, the processor  190  may monitor the temperature of the chamber  110  and the pressure in the chamber  110  through the sensor  160 . 
     In some implementations, the processor  190  may include at least one physical component among an electric circuit, application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, or microprocessors. 
     In some implementations, the cooking apparatus  100  may include a pressure sensor  162  provided at a flow path between the pump  130  and the chamber  110  and configured to sense a pressure in the chamber  110 , and may include a temperature sensor  161  provided on the outer surface of the chamber  110  and configured to sense a temperature of the chamber  110 . Positions of the pressure sensor  162  and the temperature sensor  161  are exemplarily illustrated. When necessary, the pressure sensor  162  and the temperature sensor  161  may be provided at different positions in designing a cooking apparatus. 
     The pressure sensor  162  may sense a hydraulic pressure of water flowing on the flow path between the pump  130  and the chamber  110  to sense a pressure in the chamber  110 . The temperature sensor  161  may sense a temperature of the outer surface of the chamber  110  to sense a temperature of the chamber  110 . The pressure sensor  162  and the temperature sensor  161  maybe digital sensors and may provide a sensed pressure and a sensed temperature to the processor  190 . 
     The processor  190  may control the pump  130  such that the pump  130  supplies water into the chamber  110  until a pressure in the chamber  110 , sensed by the pressure sensor  162 , reaches a predetermined pressure. The predetermined pressure may be determined through experiments to guarantee excellent cooking performance and quality cooking with respect to an object. For example, the predetermined pressure may be 9 atm. 
     Specifically, the processor  190  may compare a pressure in the chamber  110 , sensed by the pressure sensor  162 , with a predetermined pressure stored in the memory. In case the pressure in the chamber  110  is lower than the predetermined pressure as a result of comparison, the processor  190  may provide a control signal to the pump  130 , and the pump  130  may operate based on the control signal supplied by the processor  190  and may supply water into the chamber  110  forcibly. 
     The processor  190  may continue to compare a pressure in the chamber  110 , sensed by the pressure sensor  162 , with a predetermined pressure stored in the memory. When the pressure in the chamber  110  reaches the predetermined pressure, the processor  190  may cut off the supply of a control signal, and the pump  130  may cut off the supply of water. 
     Further, the processor  190  may control the heater  120  such that the heater  120  heats the chamber  110  until a temperature of the chamber  110 , sensed by the temperature sensor  161 , reaches a predetermine temperature. The predetermined temperature may be determined through experiments to guarantee excellent cooking performance and quality cooking with respect to an object. 
     Specifically, the processor  190  may compare a temperature of the chamber  110 , sensed by the temperature sensor  161 , with a predetermined temperature stored in the memory. In case the temperature of the chamber  110  is lower than the predetermined temperature as a result of comparison, the processor  190  may provide a control signal to the heating controller  121 , and the heating controller  121  may operate based on the control signal supplied by the processor  190  and may supply electric currents to the coil  122 . By the electric currents supplied to the coil  122 , induced currents may be generated in the chamber  110 , and the chamber  110  may be heated by Joule&#39;s heat caused by the induced currents. 
     The processor  190  may continue to compare a temperature of the chamber  110 , sensed by the temperature sensor  161 , with a predetermined temperature stored in the memory. In case the temperature of the chamber  110  reaches the predetermined temperature, the processor  190  may cut off the supply of a control signal, and the heating controller  121  may cut off the supply of electric currents. 
     The predetermined temperature may be determined based on a boiling point based on a pressure in the chamber  110 . Specifically, the predetermined temperature may be determined not to exceed a boiling point based on a pressure in the chamber  110 . That is, when the chamber  110  is heated using the above-described method, the processor  190  may control the heater  120  such that the temperature of the chamber  110  does not exceed a boiling point based on the pressure in the chamber  110 . 
     Below, example cooking processes will be described with reference to  FIGS. 5 and 6 . 
     In some implementations, referring to  FIG. 5 , a processor  190  may control a pump  130  such that the pump  130  supplies water into a chamber  110  until a pressure in the chamber  110  reaches a predetermined pressure. Then, the processor  190  may control a heater  120  such that a temperature of the chamber  110  does not exceed a boiling point based on the predetermined pressure. For instance, the processor  190  may control the heater  120 , while maintaining the predetermined pressure in the chamber  110 , to increase the temperature of the chamber  110  to a target temperature that is lower than the boiling point. 
     For instance, the processor  190  may provide a control signal to the pump  130  until a pressure in the chamber  110  reaches 9 atm. The pump  130  may forcibly supply water into the chamber  110  based on the control signal provided by the processor  190 , and the pressure in the chamber  110  may be gradually increased to 9 atm (A). 
     When the pressure in the chamber  110  reaches 9 atm, the processor  190  may provide a control signal to a heating controller  121  until a temperature of the chamber  110  reaches 160 degrees Celsius that does not exceeds a boiling point (about 175 degrees Celsius) based on 9 atm. The heating controller  121  may supply electric currents to a coil  122  based on the control signal provided by the processor  190  to heat the chamber  110 , and the temperature of the chamber  110  is gradually increased to 160 degrees Celsius (B). 
     The processor  190  may continue to monitor a pressure in the chamber  110  and a temperature of the chamber  110  through a pressure sensor  162  and a temperature sensor  161 . According to the above-described control method of the pump  130  and the heater  120 , the processor may maintain the pressure in the chamber  110  at a pressure of 9 atm and maintain the temperature of the chamber  110  at a temperature of 160 degrees Celsius. 
     In some implementations, referring to  FIG. 6 , a processor  190  may control a pump  130  such that the pump  130  supplies water into a chamber  110  until a pressure in the chamber  110  reaches a predetermined pressure, and, at the same time, may control a heater  120  such that a temperature of the chamber  110  does not exceed a boiling point based on the current pressure in the chamber  110 . For instance, the processor  190  may be configured to control the pump  130  to supply water into the chamber  110  to increase the pressure in the chamber  110  to the predetermined pressure while controlling the heater  120  to increase the temperature of the chamber  110  to a target temperature that is lower than the boiling point corresponding to the pressure in the chamber. 
     For example, the processor  190  may provide a control signal to the pump  130  until a pressure in the chamber  110  reaches 9 atm. The pump  130  may forcibly supply water into the chamber  110  based on the control signal provided by the processor  190 , and the pressure in the chamber  110  may be slowly increased (A′). 
     At the same time, the processor  190  may provide a control signal to a heating controller  121  such that a temperature of the chamber  110  is increased within a range where the temperature of the chamber  110  does not exceed a boiling point based on an increasing pressure in the chamber  110 . The heating controller  121  may supply electric currents to a coil  122  based on the control signal provided by the processor  190  to heat the chamber  110 , and the temperature of the chamber  110  may be gradually increased (B′). 
     That is, the operation of generating a high pressure in the chamber  110  and the operation of heating the chamber  110  to a high temperature may be performed simultaneously. Accordingly, as illustrated in  FIG. 6 , a pressure in the chamber  110  and a temperature of the chamber  110  are gradually increased. Thus, the temperature of the chamber  110  may reach 160 degrees Celsius at a time point when the pressure in the chamber  110  reaches 9 atm. 
     In some examples, an object in the chamber  110  may be heated and cooked for a predetermined period in a high-temperature high-pressure state that is created according to the above-described method. 
     The present disclosure, as described above, may perform a cooking operation under a high-pressure environment that is created by forcibly supplying water. Accordingly, the high-pressure environment may be rapidly created and a cooking period may be shortened. Additionally, an object may be heated to a higher temperature, thereby ensuring quality cooking for the object. 
     The cooking apparatus  100  may further include a pressure release valve  140  to release the pressure generated in the chamber  110  after the object is cooked. 
     As illustrated in  FIG. 4 , the pressure release valve  140  may be connected to the inner space of the chamber  110 , and may optionally leak water filling the chamber  110  to release the pressure generated in the chamber  110 . 
     The pressure release valve  140  may be controlled by the processor  190 . That is, the processor  190  may block the pressure release valve  140  before the above-described cooking operation and may open the pressure release valve  140  after the cooking operation. 
     For example, during the process of generating a pressure in the chamber  110  for cooking an object, the processor  190  may control the pump  130  such that the pump  130  supplies water into the chamber  110  after the pressure release valve  140  is opened. Accordingly, air filling the chamber  110  may leak outwards through the pressure release valve  140 . Then when the chamber  110  is full of water, the processor  190  may block the pressure release valve  140  and may control the pump  130  such that the pump  130  continues to supply water into the chamber  110  to generate a pressure in the chamber  110 . 
     After the cooking operation, the processor  190  may open the pressure release valve  140  to discharge the water filling the chamber  110 . 
     Referring back to  FIGS. 5 and 6 , when the pressure release valve  140  is opened, the pressure in the chamber  110  is decreased (C), and, due to a decrease in a boiling point caused by the decreased pressure, water having been heated to a high temperature may be turned into steam. In this case, the temperature in the chamber  110  may be decreased by evaporation heat of the water (C). 
     A speed at which water is evaporated when the pressure release valve  140  is opened may be determined based on a degree to which the pressure release valve  140  is opened, and, based on the speed at which water is evaporated, a moisture content of an object may be determined. 
     Specifically, in case water leaks rapidly out of the chamber  110  as the pressure release valve  140  is wide open (when a large amount of water is evaporated), a moisture content of an object may be decreased. In case water leaks slowly out of the chamber  110  as the pressure release valve  140  is narrowly opened (when a small amount of water is evaporated), a moisture content of an object may be increased. 
     Accordingly, the processor  190  may control a degree to which the pressure release valve  140  is opened to adjust a moisture content. 
     For example, the processor  190  may control the degree to which the pressure release valve  140  is opened based on a predetermined moisture content. The predetermined moisture content may be determined through experiments to guarantee quality cooking for an object. 
     Additionally, the processor  190  may control the degree to which the pressure release valve  140  is opened according to a user&#39;s instruction. 
     Referring to  FIG. 4 , the user may input a user instruction in relation to a moisture content through any operation part  200 . For example, user A may input a user instruction for cooking al dente rice through the operation part  200 , and the input user instruction may be provided to the processor  190 . 
     The processor  190  may open the pressure release valve  140  at a ratio higher than a reference ratio based on the user instruction after the cooking operation is finished. Accordingly, a moisture content of the rice may be lower than the predetermined moisture content such that al dente rice is cooked. 
     User B may input a user instruction for cooking soft rice through the operation part  200 , and the input user instruction may be provided to the processor  190 . 
     The processor  190  may open the pressure release valve  140  at a ratio lower than the reference ratio based on the user instruction after the cooking operation is finished. Accordingly, a moisture content of the rice may be higher than the predetermined moisture content such that soft rice is cooked. 
     The present disclosure, as described above, may adjust a moisture content of an object, thereby making it possible to ease the cumbersome process of adjusting an amount of water previously for a cooking operation and to guarantee quality cooking to meet the taste of the user. 
     In some implementations, the cooking apparatus  100  may further include a gas-liquid separator  170  that separates water and steam discharged through the pressure release valve  140 . 
     As described above, when the pressure release valve  140  is opened, water may be turned into steam. However, when a predetermined period passes after the pressure release valve  140  is opened, the temperature in the chamber  110  may be decreased by evaporation heat of water, and the water may be no longer evaporated. Accordingly, water as well as steam may be discharged through the pressure release valve  140 . 
     The gas-liquid separator  170  may be connected to an output port of the pressure release valve  140  and may separate water and steam discharged through the pressure release valve  140  structurally. The gas-liquid separator  170  may be implemented through various devices that are used in the art to which the disclosure pertains. For instance, the gas-liquid separator  170  may include a vessel or a reservoir having an inlet configured to receive mixture of gas and liquid and an outlet configured to discharge gas separated from the mixture. 
     The steam structurally separated through the gas-liquid separator  170  may be discharged to the atmosphere, and the water may be collected through an additional pipe. 
     In some implementations, the cooking apparatus  100  may further include a condenser  180  that condenses steam discharged through the pressure release valve  140 . 
     The condenser  180  may be connected to the output port of the pressure release valve  140  or may be connected to an output port of the gas-liquid separator. The condenser  180  may condense steam having a relatively large volume into water having a relatively small volume. The condenser  180  may be implemented through various devices that are used in the art to which the disclosure pertains. 
     The present disclosure, as described above, may condense steam that is discharged after the cooking operation, thereby reducing noise caused by the discharge of steam after the cooking operation and helping to prevent danger caused by the discharge of high-temperature steam. 
     The present disclosure described above may be replaced, modified and changed in various different forms by one having ordinary skill in the art to which the present disclosure pertains without departing from the technical spirit of the disclosure. Thus, the disclosure is not limited to the above-described implementations and the accompanying drawings.