Boiler for steam cooking

Abstract

The present invention relates to a steam cooking boiler, and more specifically, to a steam cooking boiler that uses an induction heater or a PTC heater to generate steam for use in a steam cooker and supplies it to a cooking unit. A steam cooking boiler for supplying steam to a cooking section of a steam cooker comprises: a water tank in which water is supplied and stored; a lower heater section for heating the water tank at the bottom of the water tank; a discharge pipe arranged to contact the upper surface of the water tank and forming a path for steam evaporated from the water tank and discharged upward; and an upper heater section for heating the discharge pipe at the top of the discharge pipe.

Description

Technology Field

[0001] The present invention relates to a steam cooking boiler, and more specifically, to a steam cooking boiler that uses an induction heater or a PTC heater to generate steam for use in a steam cooker and supplies it to a cooking unit. Background Technology

[0002] To cook large quantities of rice, cooking appliances that steam the rice using steam are used rather than those that boil it with water. In food service for the military or schools, large-scale cooking appliances that supply steam and cook the rice using the heat from the supplied steam are mainly used, rather than the method of cooking rice by boiling water.

[0003] A cooking appliance consists of a boiler for generating steam and a cooking unit that cooks rice by stacking shelves on which rice is placed. Since high-temperature, high-heat steam must be supplied to the cooking unit, a boiler capable of converting water into steam and supplying it to the cooking unit is required.

[0004] Conventional cooking boilers primarily used electric heaters to heat water and generate steam, but they had the problem of being inefficient due to the high amount of electricity consumed. Prior art literature

[0005] Registered Patent No. 10-1662447 (Registered Sep. 27, 2016) Registered Patent No. 10-1857092 (Registered May 4, 2018) Registered Patent No. 10-1907827 (Registered Oct. 5, 2018) Registered Patent No. 10-2053590 (Registered Dec. 2, 2019) The problem to be solved

[0006] Therefore, the present invention aims to provide a steam cooking boiler that can efficiently utilize electricity by efficiently heating water with a heater, forming steam, and supplying it to the cooking unit of a steam cooker. means of solving the problem

[0007] To achieve the above objective, the present invention provides a steam cooking boiler for supplying steam to a cooking unit of a steam cooker, wherein the boiler comprises: a water tank in which water is supplied and stored; a lower heater unit for heating the water tank at the bottom of the water tank; a discharge pipe arranged to contact the upper surface of the water tank and forming a path for steam evaporated from the water tank and discharged upward; and an upper heater unit for heating the discharge pipe at the top of the discharge pipe.

[0008] In the present invention, the water tank is characterized by being made of a magnetically inductive SUS material and capable of being heated by receiving an induction current from an induction heater.

[0009] In the present invention, the lower heater part is characterized by comprising a first induction heater made of a coil and a first temperature sensor mounted on the first induction heater for measuring the temperature of the first induction heater.

[0010] In the present invention, the discharge pipe is characterized by being made of a magnetically inductive SUS material and capable of being heated by receiving an induction current from an induction heater.

[0011] In the present invention, the upper heater portion is characterized by comprising a second induction heater formed as a coil that contacts the upper part of the discharge pipe, and a second temperature sensor mounted on the second induction heater to measure the temperature of the second induction heater.

[0012] In the present invention, the upper heater part is characterized by comprising a PTC heater arranged to be in contact with the upper part of the discharge pipe, and a second temperature sensor mounted on the PTC heater to measure the temperature of the PTC heater.

[0013] In the present invention, the discharge pipe is characterized by being formed in a zigzag shape to increase the contact area.

[0014] The boiler of the present invention is characterized by further including a water level sensor formed on the side of a water tank to measure the water level of the water tank, a first shut-off valve installed on the lower side of the water tank to turn ON / OFF the supply of water to the water tank, and a second shut-off valve installed at the end of the discharge pipe to turn ON / OFF the supply of steam generated in the water tank.

[0015] In the present invention, the boiler further comprises a driving unit for supplying water to a water tank, discharging steam, and driving a lower heater unit and an upper heater unit, wherein the driving unit comprises: a power supply unit that supplies control power to a control unit and supplies operating power to an induction coil; a control unit that controls the ON / OFF operation of a first shut-off valve and a second shut-off valve and controls the operation of a lower heater unit and an upper heater unit; and a switching module that receives a control signal from the control unit and supplies driving power to drive the lower heater unit and the upper heater unit. Effects of the invention

[0016] Since the present invention uses an induction heater as a heater for heating a boiler, it has the advantage of being able to increase energy efficiency compared to the heating wire method.

[0017] In addition, the present invention has the advantage of being able to raise the steam to a desired temperature by using an induction heater to heat the water tank and, at the same time, heating the steam discharged from the water tank from the top.

[0018] In addition, the present invention has the advantage of preventing overheating and damage to the coil because it is equipped with a temperature sensor to protect the coil constituting the induction heater. Brief explanation of the drawing

[0019] FIG. 1 is an overall configuration diagram of a steam cooker according to the present invention. FIG. 2 is an overall perspective view of a first embodiment of a steam cooking boiler according to the present invention. FIG. 3 is an exploded perspective view of the boiler of FIG. 2. FIG. 4 is a block diagram illustrating the operation relationship of the boiler of FIG. 2. FIG. 5 is an overall perspective view of a second embodiment of a steam cooking boiler according to the present invention. FIG. 6 is an exploded perspective view of the boiler of FIG. 5. FIG. 7 is a block diagram illustrating the operating relationship of the boiler of FIG. 5. Specific details for implementing the invention

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, this description is intended to be detailed enough for a person skilled in the art to easily practice the invention, and does not imply that the technical scope and concept of the present invention are limited thereby.

[0022] FIG. 1 is a diagram showing the configuration of a steam cooker (1) according to the present invention. As shown in the drawing, the steam cooker (1) consists of an upper housing (2) in which a cooking section (10) is formed inside, and a lower housing (4) in which a boiler (20) is provided. The upper housing (2) is provided with an upper door (3) to allow shelves containing rice to be placed in layers into the cooking section (10), and the lower housing (4) is provided with a lower door (5) for maintaining or installing the boiler (20). Additionally, wheels (5) may be provided on the bottom surface of the lower housing (4) to enable movement. The boiler (20) is fixed and supported on a support shelf (30).

[0023] Inside the cooking unit (10), a steam supply pipe (11) is provided through which steam is supplied via a boiler (20), and a temperature sensor (12) is also provided to measure the temperature inside the cooking unit (10).

[0024] Hereinafter, specific configurations of the boiler (20) of the first embodiment according to the present invention will be described in detail with reference to FIGS. 2 to 4.

[0025] A boiler (20) provided inside a lower housing (4) comprises a water tank (21) into which water is supplied and stored, a lower heater unit (22) including a first induction heater (221) that heats the water tank (21) on the bottom surface of the water tank (21), a discharge pipe (23) that forms a path for steam evaporated from the water tank (21) and discharged upwards and is arranged to contact the upper surface of the water tank (21), an upper heater unit (24) including a second induction heater (241) that heats the discharge pipe from the upper surface of the discharge pipe (23), and a driving unit (25) for supplying water to the water tank (21), discharging steam, and driving the lower heater unit (22) and the upper heater unit (24).

[0026] Water is supplied to the water tank (21) through a supply pipe (27), and a first shut-off valve (28) is installed in the supply pipe (27) connected to the water tank (21). The first shut-off valve (28) is equipped as a solenoid valve and can be controlled by a control unit. A lower heater unit (22) is installed on the bottom surface of the water tank (21), and an upper heater unit (24) is installed on the top surface of the water tank (21). Additionally, a water level sensor (26) is installed on one side of the water tank (21), and the water level value measured by the water level sensor (26) is transmitted to a control unit (252). The control unit (252) controls the first shut-off valve (28) to regulate the amount of water supplied to the water tank (21).

[0027] The lower heater section (22) consists of a first induction heater (221) made of a coil and a first temperature sensor (222) mounted on the first induction heater (221) to measure the temperature of the first induction heater (221). The first induction heater (221) consists of a coil (2211), a core (2212) around which the coil (2211) is wound, and a bolt hole (2213) formed at the corner of the core (2212). When current flows through the coil (2211), an induced current flows, and the water tank (21) is heated by the induced current. To allow the induced current to flow through the water tank (21) and heat it, the water tank (21) is made of a magnetically inductive SUS material. Magnetically inductive SUS materials may include ferritic stainless steel or martensitic stainless steel. Representative ferritic stainless steels include SUS 409, SUS 430, SUS 439, and SUS 444. Additionally, martensitic stainless steels include SUS 410, SUS 420, and SUS 440. Furthermore, although austenitic stainless steel is non-magnetic and magnetic induction is difficult, some magnetic properties may develop after cold working, and austenitic stainless steel with developed magnetic properties may be capable of magnetic induction. The coil (2211) is wound around a core (2212) such as ferrite. The ferrite acts as a shield to block the induced current. To prevent overheating and damage to the coil (2211) caused by the induced current, a first temperature sensor (222) is installed on the coil (2211) to measure the temperature of the coil (2211). The measured temperature value is transmitted to the control unit (252). The first induction heater (221) is installed using a bolt (223) so as to be spaced a certain distance from the water tank (21) or to be in direct contact with the bottom surface of the water tank (21).

[0028] A discharge pipe (23) is connected to the top plate of the water tank (21). The discharge pipe (23) forms a path for steam to be discharged. The discharge pipe (23) is formed in a zigzag shape to increase the contact area, and is formed in the form of a straight pipe (231) and a curved pipe (232). The curved pipe (232) can be formed by connecting an elbow. A second shut-off valve (29) is installed at the end of the discharge pipe (23). The second shut-off valve (29) controls the amount of steam discharged from the discharge pipe (23) to supply or turns the steam supply ON / OFF. The second shut-off valve (29) may be a solenoid valve, and the operation of the solenoid valve can be controlled by a control unit (252). The discharge pipe (23) is connected to the steam supply pipe (11).

[0029] An upper heater section (24) is installed on the upper part of the discharge pipe (23). The upper heater section (24) consists of a second induction heater (241) formed by a coil (2411) and a second temperature sensor (242) mounted on the second induction heater (241) to measure the temperature of the second induction heater (241). The second induction heater (241) may be installed directly on the upper part of the discharge pipe (23) or installed at a certain distance apart. Accordingly, the discharge pipe (23) is made of a magnetically inductive SUS material so as to receive the induced current from the second induction heater (241). Magnetically inductive SUS materials may include ferritic stainless steel or martensitic stainless steel. Representative ferritic stainless steels include SUS 409, SUS 430, SUS 439, and SUS 444. In addition, SUS 410, SUS 420, and SUS 440 can be used as martensitic stainless steels. Also, although austenitic stainless steel is non-magnetic and magnetic induction is difficult, some magnetic properties may be generated after cold working, and austenitic stainless steel with magnetic properties may be capable of magnetic induction. By heating the discharge pipe (23) with the second induction heater (241), the steam generated in the water tank (21) is heated once more to produce steam at a higher temperature. A second temperature sensor (242) for protecting the coil (2411) of the second induction heater (241) measures the temperature of the coil (2411) and transmits the temperature value to the control unit (252). The control unit (252) regulates the amount of current supplied to the coil to prevent overheating and burnout of the coil.

[0030] The second induction heater (241) installed on the upper part of the discharge pipe (23) is installed with bolts (243). The second induction heaters (241) may be installed so as to be spaced apart by a certain distance or so as to be in contact with each other.

[0031] FIG. 4 is a block diagram illustrating the process driven by the driving unit (25). As shown in FIG. 1, the driving unit (25) is provided on one side of the cooking unit (10). Referring to FIG. 4, the driving unit (25) comprises a power supply unit (251) that supplies control power to the control unit (252) and supplies operating power to the induction coil, a control unit (252) that controls the ON / OFF operation of the first shut-off valve (28) and the second shut-off valve (29) and controls the operation of the lower heater unit (22) and the upper heater unit (24), and a switching module (253) that receives a control signal from the control unit (252) and supplies driving power to drive the first induction heater (221) and the second induction heater (241). The power supply unit (251) supplies power and includes a switch for turning the power ON / OFF. The power supply unit (251) supplies control power and operating power to drive the induction heater. In the configuration of FIG. 4, a solid line indicates that power or a driving signal is transmitted, and a dotted line indicates a control signal in which a sensed value is transmitted to the control unit. As shown in the drawing, when power is applied by a switch, the power supply unit (251) supplies control power to drive the control unit (252). The control unit (252) receives the water level value from the water level sensor (26) and controls the ON / OFF of the first opening / closing valve (28) to regulate the water level of the water tank (21). In addition, the control unit (252) measures the temperature inside the cooking unit from the temperature sensor (12) of the cooking unit (10) and transmits it to the control unit (252), and the control unit (252) receives the temperature value and controls the ON / OFF of the second opening / closing valve (29) so as to regulate the amount of steam supplied into the cooking unit. Additionally, the control unit (252) regulates the current amount of the switching module (253). The switching module (252) receives AC power from the power supply unit (251) and uses a multi-stage current inverter to form a constant frequency. Finally, the switching module (252) supplies a current of a constant frequency to the coil to generate an induced current, thereby enabling the water tank (21) or the discharge pipe (23) to be heated.The control unit (253) receives the temperature values ​​of the first temperature sensor and the second temperature sensor to protect the coils of the first induction heater (221) and the second induction heater (241), and adjusts the amount of current transmitted to the coils to prevent overheating and damage to the coils.

[0033] FIGS. 5 to 7 illustrate a boiler (20') of a second embodiment according to the present invention. With reference to FIGS. 5 to 7, the specific configurations of the boiler (20') of the second embodiment will be described in detail.

[0034] A boiler (20') provided inside a lower housing (4) comprises a water tank (21) into which water is supplied and stored, a lower heater unit (22) including a first induction heater (221) that heats the water tank (21) on the bottom surface of the water tank (21), a discharge pipe (23) arranged to contact the upper surface of the water tank (21) and forming a path for steam evaporated from the water tank (21) and discharged upward, an upper heater unit (24') including a PTC heater (241') that heats the discharge pipe from the upper part of the discharge pipe (23), and a driving unit (25) for supplying water to the water tank (21), discharging steam, and driving the lower heater unit (22) and the upper heater unit (24').

[0035] Water is supplied to the water tank (21) through a supply pipe (27), and a first shut-off valve (28) is installed in the supply pipe (27) connected to the water tank (21). The first shut-off valve (28) is equipped as a solenoid valve and can be controlled by a control unit. A lower heater unit (22) is installed on the bottom surface of the water tank (21), and an upper heater unit (24') is installed on the top surface of the water tank (21). Additionally, a water level sensor (26) is installed on one side of the water tank (21), and the water level value measured by the water level sensor (26) is transmitted to a control unit (252). The control unit (252) controls the first shut-off valve (28) to regulate the amount of water supplied to the water tank (21).

[0036] The lower heater section (22) consists of a first induction heater (221) made of a coil and a first temperature sensor (222) mounted on the first induction heater (221) to measure the temperature of the first induction heater (221). The first induction heater (221) consists of a coil (2211), a core (2212) around which the coil (2211) is wound, and a bolt hole (2213) formed at the corner of the core (2212). When current flows through the coil (2211), an induced current flows, and the water tank (21) is heated by the induced current. To allow the water tank (21) to be heated by the flow of induced current, the water tank (21) is made of a SUS material capable of magnetic induction. The coil (2211) is wound around a core (2212) such as ferrite. The ferrite acts as a shield to block the induced current. To prevent overheating and damage to the coil (2211) caused by the induced current, a first temperature sensor (222) is installed in the coil (2211) to measure the temperature of the coil (2211). The measured temperature value is transmitted to the control unit (252). The first induction heater (221) is installed using a bolt (223) so as to be spaced a certain distance from the water tank (21) or to be in direct contact with the bottom surface of the water tank (21).

[0037] A discharge pipe (23) is connected to the top plate of the water tank (21). The discharge pipe (23) forms a path for steam to be discharged. The discharge pipe (23) is formed in a zigzag shape to increase the contact area, and is formed in the form of a straight pipe (231) and a curved pipe (232). The curved pipe (232) can be formed by connecting an elbow. A second shut-off valve (29) is installed at the end of the discharge pipe (23). The second shut-off valve (29) controls the amount of steam discharged from the discharge pipe (23) to supply or turns the steam supply ON / OFF. The second shut-off valve (29) may be a solenoid valve, and the operation of the solenoid valve can be controlled by a control unit (252). The discharge pipe (23) is connected to the steam supply pipe (11).

[0038] An upper heater unit (24') is installed at the top of the discharge pipe (23). The upper heater unit (24') consists of a PTC (Positive Temperature Coefficient) heater (241') and a second temperature sensor (242') mounted on the PTC heater (241') to measure the temperature of the PTC heater (241'). The PTC heater (241') can be installed directly at the top of the discharge pipe (23) or installed at a certain distance apart. By heating the discharge pipe (23) with the PTC heater (241'), the steam generated in the water tank (21) is heated once more to produce steam at a higher temperature. The PTC heater (241') is a heater that utilizes the property of electrical resistance changing with temperature, mainly using ceramic materials. The key to the PTC heater is the material, and mainly ceramic materials such as barium titanate are used; barium titanate exhibits the property of its electrical resistance increasing rapidly when the temperature exceeds a certain level. A PTC heater uses a heat sink to dissipate the generated heat, and an insulator is included between the heat sink and the electrode to prevent electrical leakage and enhance safety. The operating principle of the PTC heater is that when the temperature of the material is low, the resistance is low, causing a large current to flow and generate a large amount of heat. Subsequently, when the temperature exceeds a certain level, the resistance increases rapidly, reducing the current flow and providing an automatic temperature control function to prevent further overheating. If necessary, a second temperature sensor (242') is installed on the PTC heater (241') to measure the temperature of the PTC heater (241'), and the measured value is transmitted to the control unit (252). The control unit (252) may adjust the amount of current of the PTC heater according to the temperature measurement value to prevent overheating and damage to the PTC heater (241').

[0039] A PTC heater (241') installed on the upper part of the discharge pipe (23) is installed using a bolt (243). Using the bolt (243), the PTC heater (241') can be installed so as to be spaced apart from the discharge pipe (23) at a certain distance or so as to be in contact with each other.

[0040] FIG. 7 is a block diagram illustrating the process driven by the driving unit (25). As shown in FIG. 1, the driving unit (25) is provided on one side of the cooking unit (10). Referring to FIG. 7, the driving unit (25) comprises a power supply unit (251) that supplies control power to the control unit (252) and supplies operating power to the induction coil and the PTC heater (241'), a control unit (252) that controls the ON / OFF operation of the first shut-off valve (28) and the second shut-off valve (29) and controls the operation of the lower heater unit (22) and the upper heater unit (24'), and a switching module (253) that receives a control signal from the control unit (252) and supplies driving power to drive the first induction heater (221) and the second induction heater (241). The power supply unit (251) supplies power and includes a switch for turning the power ON / OFF. The power supply unit (251) supplies control power and operating power to drive the induction heater and PTC heater. In the configuration of FIG. 7, a solid line indicates that power or a driving signal is transmitted, and a dotted line indicates a control signal in which a sensed sensing value is transmitted to the control unit. As shown in the drawing, when power is applied by a switch, the power supply unit (251) supplies control power to drive the control unit (252). The control unit (252) receives the water level value from the water level sensor (26) and controls the ON / OFF of the first opening / closing valve (28) to regulate the water level of the water tank (21). Additionally, the control unit (252) measures the temperature inside the cooking unit from the temperature sensor (12) of the cooking unit (10) and transmits it to the control unit (252). The control unit (252) receives the temperature value and controls the ON / OFF of the second shut-off valve (29) to regulate the amount of steam supplied into the cooking unit. Additionally, the control unit (252) regulates the current amount of the switching module (253). The switching module (252) uses a multi-stage current inverter to receive AC power from the power supply unit (251) and form a constant frequency.Finally, the switching module (252) supplies a current of a certain frequency to the coil to generate an induced current, thereby enabling the water tank (21) or the discharge pipe (23) to be heated. Additionally, the power supply unit (251) supplies AC power to the PTC heater (241') so that the PTC heater (241') can be heated. The control unit (253) receives the temperature values ​​from the first temperature sensor and the second temperature sensor to protect the coils of the first induction heater (221) and the PTC heater (241'), and adjusts the amount of current transmitted to the coil or the PTC heater (241') to prevent overheating and damage to the heater.

[0042] Although the embodiments described above are exemplary, it is obvious to those skilled in the art that the present invention may be embodied in various other forms without departing from the spirit and scope thereof. Accordingly, the embodiments described above should be regarded as exemplary rather than restrictive, and all embodiments within the scope of the appended claims and their equivalents shall be deemed to be included within the scope of the present invention. Explanation of the symbols

[0043] 1 : Steam cooker 2 : Upper housing 3 : Upper door 4: Lower housing 5 : Bottom door 6 : Wheel 10 : Cooks 11: Steam supply pipe 12: Temperature sensor 20, 20' : Boiler 21 : Aquarium 22: Lower heater section 23 : Discharge pipe 24, 24' : Upper heater section 25 : Drive unit 26 : Water level sensor 27 : Supply pipe 28 : First shut-off valve 29 : Second shut-off valve 30 : Support shelf

Claims

Claim 1 A steam cooking boiler for supplying steam to a cooking section of a steam cooker, wherein the boiler comprises: a water tank in which water is supplied and stored; a lower heater section for heating the water tank at the bottom of the water tank; a discharge pipe arranged to contact the upper surface of the water tank and forming a path for steam evaporated from the water tank and discharged upward; and an upper heater section for heating the discharge pipe at the top of the discharge pipe. Claim 2 A steam cooking boiler according to claim 1, characterized in that the water tank is made of a self-inductive SUS material and can be heated by receiving an induction current from an induction heater. Claim 3 A steam cooking boiler according to paragraph 2, wherein the lower heater part comprises a first induction heater made of a coil and a first temperature sensor mounted on the first induction heater to measure the temperature of the first induction heater. Claim 4 A steam cooking boiler according to paragraph 3, characterized in that the discharge pipe is made of a self-inductive SUS material and can be heated by receiving an induction current from an induction heater. Claim 5 A steam cooking boiler according to claim 4, wherein the upper heater part comprises a second induction heater formed as a coil and in contact with the upper part of the discharge pipe, and a second temperature sensor mounted on the second induction heater to measure the temperature of the second induction heater. Claim 6 A steam cooking boiler according to paragraph 3, wherein the upper heater part comprises a PTC heater positioned to be in contact with the upper part of the discharge pipe and a second temperature sensor mounted on the PTC heater to measure the temperature of the PTC heater. Claim 7 A steam cooking boiler according to claim 5 or 6, characterized in that the discharge pipe is formed in a zigzag shape to increase the contact area. Claim 8 A steam cooking boiler according to claim 1, characterized in that the boiler further comprises: a water level sensor formed on the side of the water tank to measure the water level of the water tank; a first shut-off valve installed on the lower side of the water tank to turn ON / OFF the supply of water to the water tank; and a second shut-off valve installed at the end of the discharge pipe to turn ON / OFF the supply of steam generated in the water tank. Claim 9 In claim 8, the above boiler further comprises a driving unit for supplying water to the water tank and discharging steam, and for driving the lower heater unit and the upper heater unit, wherein the driving unit comprises: a power supply unit that supplies control power to a control unit and supplies operating power to an induction coil; a control unit that controls the ON / OFF operation of the first shut-off valve and the second shut-off valve and controls the operation of the lower heater unit and the upper heater unit; and a switching module that receives a control signal from the control unit and supplies driving power to drive the lower heater unit and the upper heater unit.

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