JP2010054171A - Steam generator and heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steam generator having high steam generation efficiency by reducing accumulation of scale, and also to provide a heating cooker using the steam generator. <P>SOLUTION: The steam generator 10 is provided with: a metallic housing 2, a water supply port 3 for supplying water to inside of the housing 2, a steam generation heater 4 embedded in the housing 2 and evaporating water supplied from the water supply port 3, and a discharge port 8 for discharging steam generated by the steam generation heater 4. Silicone paint is applied to the inner face of the housing 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a steam generator that generates steam and a cooking device using the same.

  A cooking device using a conventional steam generator is disclosed in Patent Document 1. In this heating cooker, a steam generator is attached to the outer wall of the heating chamber for storing the food. The steam generator has a housing made of a metal die cast such as aluminum or aluminum alloy. The housing is hermetically formed with an opening surface of a box-shaped main body portion closed by a lid portion and having a cavity inside.

  A steam generating heater is cast and embedded in the wall surface of the housing. A water supply port is formed at one side of the housing at the center in the vertical direction. The water supply port is connected to the water supply tank, and water is supplied into the housing through the water supply port. A steam discharge port facing the heating chamber is provided at the top of the housing.

  When water is supplied into the steam generator from the water supply port, the water is stored at the bottom of the housing, and steam is generated by driving the steam generating heater. The generated steam rises in the housing and comes into contact with the wall surface of the hot housing to be further heated. As a result, high-temperature steam is generated, and the steam is discharged into the heating chamber through the discharge port. Then, the cooked food is cooked by the steam supplied into the heating chamber.

  In addition, a hydrophilic coating is applied to the inner surface of the housing. Thereby, since the contact angle of the water adhering to the inner surface of the housing is reduced, the contact area with water is increased. Therefore, steam can be generated by heating water efficiently.

JP-A-2006-84059 (pages 4-8, FIG. 3)

  However, according to the conventional steam generator, the hydrophilic coating applied to the inner surface of the housing increases the contact area with water, but it is difficult to remove scale contained in water. For this reason, the scale deposited on the inner surface of the housing forms a heat insulating layer, and heat of the housing in which the steam generating heater is embedded cannot be sufficiently transmitted to water, resulting in a problem that steam generation efficiency is lowered.

  An object of this invention is to provide the steam generator which can reduce the deposition of a scale, and can improve steam generation efficiency, and a heating cooker using the same.

  To achieve the above object, the present invention includes a metal housing, a water supply port for supplying water in the housing, a steam generating heater embedded in the housing and evaporating water supplied from the water supply port, In the steam generator having a discharge port for discharging the steam generated by the steam generating heater, the inner surface of the housing is coated with a silicone-based paint.

  According to this configuration, when water is supplied into the housing from the water supply port, water is stored at the bottom of the housing, and steam is generated by driving the steam generating heater. The generated steam rises in the housing and is further heated by exchanging heat with the housing. The vapor whose temperature has been raised is discharged through the discharge port. The inner surface of the housing is painted with a silicone-based paint, and the contact angle with water becomes about 90 °. The scale adhering to the inner surface of the housing is removed by water supply.

  According to the present invention, in the steam generator configured as described above, the silicone-based paint is black. According to this configuration, the steam is heated by heat radiation from the inner surface of the housing.

  Further, the present invention provides a metal housing, a water supply port for supplying water into the housing, a steam generation heater embedded in the housing and evaporating water supplied from the water supply port, and the steam generation heater In the steam generator having the discharge port for discharging the steam, the inner surface of the housing is coated with a non-adhesive paint, and the surface of the non-adhesive paint is subjected to a hydrophilic treatment.

  According to this configuration, when water is supplied into the housing from the water supply port, water is stored at the bottom of the housing, and steam is generated by driving the steam generating heater. The generated steam rises in the housing and is further heated by exchanging heat with the housing. The vapor whose temperature has been raised is discharged through the discharge port. The inner surface of the housing is painted with a non-adhesive paint, and the surface of the non-adhesive paint is subjected to a hydrophilic treatment. Thereby, the contact angle of water becomes small compared with the case of only painting with a non-adhesive paint, and the scale adhering to the inner surface of the housing is removed by water supply.

  According to the present invention, in the steam generator configured as described above, the non-adhesive paint is made of a silicone-based paint.

  Moreover, the cooking device of the present invention includes a steam generator configured as described above, a heating chamber in which cooked food is stored and steam is supplied from the discharge port, a circulation fan that circulates steam in the heating chamber, A circulation heater for heating steam circulated by a circulation fan is provided. According to this configuration, steam is supplied from the steam generator into the heating chamber and is circulated by the circulation fan for cooking. The steam circulated by the circulation fan is heated by the circulation heater and maintained at a predetermined temperature.

  According to the present invention, since the inner surface of the housing of the steam generator is coated with the silicone-based paint, the contact angle with water becomes about 90 °. Thereby, adhesion of a scale is reduced and steam generation efficiency can be improved. Furthermore, since the heat-resistant temperature is high, no toxic gas is generated even at a high temperature, and high-temperature steam can be generated without deteriorating safety.

  In addition, according to the present invention, since the inner surface of the housing of the steam generator is coated with a non-adhesive paint and the surface of the non-adhesive paint is subjected to a hydrophilic treatment, adhesion of scale is reduced as compared with the hydrophilic paint. Steam generation efficiency can be improved. Moreover, the contact angle of water becomes small compared with the case of only painting with a non-adhesive paint, and the steam generation efficiency can be further improved.

  Embodiments of the present invention will be described below with reference to the drawings. 1, 2, and 3 are a right side view, a front view, and a top sectional view showing the inside of the heating cooker according to the first embodiment. The heating cooker 10 has a substantially rectangular parallelepiped heating chamber 11 for storing cooked food in a main body housing 22. The side wall and the ceiling wall of the heating chamber 11 are covered and shielded by the heat shield plate 23, and the front surface is opened and closed by the door 11b.

  A temperature sensor 11 c that detects the room temperature of the heating chamber 11 is provided on the top surface of the heating chamber 11. A circulating heater 15 described later is controlled based on the temperature detected by the temperature sensor 11c. In the heating chamber 11, a tray 17 on which a placement net 17a is placed is disposed. The food W is placed on the placement net 17a.

  An outside air inflow duct 34 is formed between the main body housing 22 and the lower side and the right side of the heating chamber 11. The outside air inflow duct 34 has a suction port 34 a opened at the bottom surface of the main body housing 22. A cooling fan 35, an electrical component 33, and a magnetron 30 are disposed below the outside air inflow duct 34. An air supply duct 36 having an air supply fan 37 is disposed on the side of the outside air inflow duct 34. The air supply duct 36 opens an air supply port 38 at the front portion of one side wall 11 a of the heating chamber 11.

  The electrical unit 33 includes a drive circuit that drives each unit of the heating cooker 10, a control unit (not shown) that controls the drive circuit, and the like. The magnetron 30 supplies microwaves into the heating chamber 11 through the waveguide 31. An antenna 32 that is rotated by an antenna motor 32 a is disposed in the waveguide 31, and microwaves are uniformly supplied to the heating chamber 11.

  The cooling fan 35 takes outside air into the outside air inflow duct 34 via the suction port 34a, and cools the electrical component 33 and the magnetron 30 that generate heat. The outside air taken into the outside air inflow duct 34 flows out from an opening (not shown) formed on the back surface of the main body housing 22. Part of the outside air flows into the air supply duct 36 by driving the air supply fan 37.

  An exhaust duct 40 is led out to the rear portion of the side wall 11 a of the heating chamber 11 through an exhaust port 41. The exhaust duct 40 is formed to extend to the rear of the heating chamber 11, and the open end 40 a opens to the top surface of the main body housing 22. Further, the exhaust duct 40 is provided with a humidity sensor 42 that detects the humidity of the exhaust from the exhaust port 41.

  A steam generator 1 that supplies steam to the heating chamber 11 through the discharge port 8 is attached to the upper portion of the side wall 11 a of the heating chamber 11. A detachable water supply tank 20 is disposed on the side of the steam generator 1. A water supply pump 21 connected to the water supply port 3 of the steam generator 1 is disposed behind the water supply tank 20. When the water supply tank 20 is mounted, it is connected to the water supply pump 21 via a joint (not shown). Water is supplied from the water supply tank 20 to the steam generator 1 through the water supply pipe 21a by driving the water supply pump 21.

  A circulation duct 12 is provided behind the heating chamber 11. The circulation duct 12 has an air inlet 14 at the center of the back wall of the heating chamber 11, and a plurality of jets 13 at the periphery of the back wall of the heating chamber 11. A circulation fan 16 and a circulation heater 15 are provided in the circulation duct 12. The circulation fan 16 is rotationally driven by a fan motor 16a. The circulation fan 16 sucks the steam in the heating chamber 11 from the intake port 14 into the circulation duct 12 and blows it out from the ejection port 13. The circulation heater 15 is composed of an annular sheathed heater, and maintains the steam flowing through the circulation duct 12 at a predetermined temperature.

  FIG. 4 shows a front sectional view of the steam generator 1. FIG. 5 is a cross-sectional view taken along the line AA in FIG. The steam generator 1 has a housing 2 made of metal die casting. In the housing 2, the opening surface of the box-shaped main body 2a is closed with a lid 2b fixed with screws 2c, and a cavity is formed inside. Use of aluminum or an aluminum alloy as the material of the housing 2 is more preferable because of good castability and high thermal conductivity.

  A water supply port 3 connected to a water supply pump 21 (see FIG. 1) opens at the center portion in the vertical direction in the lid 2b of the housing 2. The main body portion 2 a is provided with a plurality of discharge ports 8 facing the side wall 11 a of the heating chamber 11.

  A steam generating heater 4 composed of a sheathed heater is disposed at the lower part of the housing 2. The steam generating heater 4 is cast and embedded in the housing 2, and is in close contact with the housing 2 so that heat of the steam generating heater 4 is efficiently transmitted to the housing 2. Thereby, the water dripped from the water supply port 3 and accumulated at the bottom of the housing 2 is evaporated by the heat transmitted from the steam generating heater 4 to the housing 2 to generate steam.

  The inner surface of the housing 2 is painted black with a silicone-based paint that is a non-adhesive paint. For this reason, the contact angle with water on the inner surface of the housing 2 is about 90 °, which is larger than in the case of hydrophilic coating. Thereby, adhesion of a scale is reduced compared with hydrophilic coating, and steam generation efficiency can be improved.

  In addition, in the case of painting with a fluorine-based paint which is another non-adhesive paint, the contact angle with water is about 110 °. When the contact angle with water exceeds 90 °, the water repellency is remarkably increased and the heat of the housing 2 cannot be transmitted, so that the steam generation efficiency is remarkably lowered. For this reason, it is possible to improve the steam generation efficiency by using a silicone-based paint having a contact angle with water of about 90 ° or less and having water repellency.

  Furthermore, the heat resistance temperature of the fluorine-based paint is about 250 ° C., and when it exceeds the heat resistance temperature, it decomposes and generates toxic gas. For this reason, the temperature of the housing 2 cannot be increased, and the temperature of the steam is lowered. On the other hand, the heat resistant temperature of the silicone-based paint is higher than that of the fluorine-based paint (for example, 550 ° C. or higher). For this reason, even if it becomes high temperature, no toxic gas is generated, and high temperature steam can be generated without reducing safety.

  In addition, by coating the inner surface of the housing 2 with black, the steam can be heated by heat radiation from the inner surface of the housing 2.

  The surface on which the discharge port 8 is formed is provided so as to protrude from the lower portion of the housing 2 in which the steam generating heater 4 is embedded. For this reason, the lower part of the housing 2, which is heated by the steam generating heater 4, is arranged away from the side wall 11 a of the heating chamber 11. Thereby, the heat-resistant structure of the heating chamber 11 can be simplified.

  A temperature sensor 9 is attached in the vicinity of the steam generating heater 4. The temperature sensor 9 is embedded in the housing 2 and monitors the temperature of the housing 2 to detect emptying. Further, the temperature sensor 9 detects insufficient heating due to a failure of the steam generating heater 4 or the like.

  A steam temperature raising heater 5 including a sheathed heater formed in a spiral shape so as to be arranged in a plurality of rows in the left-right direction is disposed on the upper portion of the housing 2. The steam temperature raising heater 5 is attached to the housing 2 by a flange portion 5 a of a non-heat generating portion, and the heat generating portion is arranged at a predetermined distance from the inner wall of the housing 2. Thereby, even if the temperature of the steam temperature raising heater 5 is increased, the temperature rise of the housing 2 can be suppressed.

  A box-shaped partition member 7 is provided around the steam heating heater 5 so as to open the upper surface and surround the steam heating heater 5. The discharge port 8 is formed in a cylindrical shape that penetrates the partition member 7, and the discharge port 8 is disposed below the bottomed partition member 7. Part of the partition member 7 is supported by being joined to the housing 2, and is disposed at a predetermined distance from the inner wall of the housing 2.

  As a result, a steam passage 6 is formed that guides the steam from the lower part of the housing 2 to the discharge port 8 through the steam heating heater 5. For this reason, it is possible to prevent a shortcut that the steam flows out from the discharge port 8 directly from the lower part of the housing 2 without passing through the steam heating heater 5, and it is possible to reliably generate the superheated steam.

  Further, since the partition member 7 is separated from the inner wall of the housing 2, overheating of the housing 2 can be prevented. Furthermore, steam flows through the external passage 6 a between the housing 2 and the partition member 7 to cool the housing 2, thereby further preventing overheating of the housing 2.

  The steam passage 6 includes an external passage 6 a outside the partition member 7 and an internal passage 6 b inside the partition member 7. The external passage 6 a and the internal passage 6 b communicate with each other at the upper end of the partition member 7, and the discharge port 8 is provided in the lower portion of the space surrounded by the partition member 7.

  The partition member 7 is formed of a metal or ceramic having higher heat resistance than the housing 2. More preferably, the partition member 7 is formed of stainless steel or the like having excellent corrosion resistance and thermal conductivity. In addition, the surface of the partition member 7 facing the steam temperature raising heater 5 is formed in a dark color by applying heat-resistant black coating. Thereby, the radiant heat of the steam temperature raising heater 5 is absorbed by the partition member 7 and the temperature rise of the housing 2 is suppressed. Moreover, the electrolytic corrosion of the junction part by the dissimilar metal between the partition member 7 and the housing 2 is prevented.

  When cooking with microwaves is started in the heating cooker 10 configured as described above, the magnetron 30 and the antenna motor 32a are driven. Further, the cooling fan 35 and the air supply fan 37 are driven. A microwave is supplied into the heating chamber 11 via the waveguide 31 by the magnetron 30, and the food W is heated by microwaves.

  Outside air flows into the outside air inflow duct 34 from the suction port 34 a by the cooling fan 35. The outside air that has flowed into the outside air inflow duct 34 cools the electrical component 33 and the magnetron 30 and is exhausted to the outside. A part of the outside air heated by cooling the electrical unit 18 and the magnetron 20 is guided to the air supply duct 36 by the air supply fan 37.

  Outside air flowing through the air supply duct 36 is supplied to the heating chamber 11 from an air supply port 38. At this time, since the air supply port 38 is arranged in the front part of the heating chamber 11, the airflow blown out from the air supply port 38 circulates along the door 11b. Thereby, dew condensation of the door 11b can be prevented by the air heated by cooling the electrical component 33 and the magnetron 30.

  The air in the heating chamber 11 is exhausted from the exhaust port 41 by supplying air from the air supply port 38, flows through the exhaust duct 40, and is released to the atmosphere from the open end 40 a. The humidity flowing through the exhaust duct 40 is detected by a humidity sensor 42. When steam is generated from the food W by microwave heating and the inside of the heating chamber 11 reaches a predetermined humidity, the end time of cooking is determined by detection of the humidity sensor 42. Thereby, cooking by a microwave is complete | finished.

  When cooking with steam, a stored water tank 20 is attached. Then, the food W is placed on the placement net 17a and cooking is started. When cooking is started, the feed water pump 21 is driven, and then the steam generating heater 4 and the steam temperature raising heater 5 are driven. Water is supplied into the housing 2 of the steam generator 1 from the water supply port 3 as shown by an arrow B (see FIG. 4) by the water supply pump 21.

  The water supplied to the housing 2 accumulates in the lower part of the housing 2 and is evaporated by the steam generating heater 4 to generate steam. At this time, the steam generating heater 4 generates heat at a temperature lower than the softening temperature of the housing 2. Further, since the steam temperature raising heater 5 is separated from the housing 2 and is shielded from the housing 2 by the partition member 7, it generates heat at a temperature higher than the softening temperature of the housing 2.

  For example, when the housing 2 is made of aluminum or an aluminum alloy, the softening temperature is about 400 ° C. For this reason, since the steam generation heater 4 only needs to evaporate water, it generates heat at about 200 ° C. Moreover, since the steam heating heater 5 generates high-temperature superheated steam, it generates heat at about 600 ° C.

  The steam generated in the lower part of the housing 2 rises in the steam passage 6 as shown by an arrow C1 (see FIG. 4) and flows through the external passage 6a outside the partition member 7 as shown by an arrow C2 (see FIG. 4). . The steam flowing through the external passage 6 a exchanges heat with the partition member 7 that has absorbed the radiant heat of the steam heating heater 5. Further, the steam flowing through the external passage 6a exchanges heat with the housing 2, and the housing 2 is cooled. At this time, fins for heat exchange may be provided on the outer surface of the partition member 7 or the inner wall of the housing 2. Thereby, heat exchange efficiency can be improved.

  The steam that has flowed into the partition member 7 from above is lowered by the steam pressure and guided to the discharge port 8. At this time, the steam is further heated by exchanging heat with the inner surface of the partition member 7 and the steam heating heater 5. Thereby, superheated steam is produced | generated and it supplies to the heating chamber 11 from the discharge port 8 as shown by arrow C3 (refer FIG. 4). A heat exchange fin may be provided on the inner surface of the partition member 7.

  The food W on the tray 17 is cooked by the superheated steam supplied into the heating chamber 11. Further, the steam in the heating chamber 11 flows into the circulation duct 12 through the intake port 14 by driving of the circulation fan 16. The steam flowing through the circulation duct 12 is heated by the circulation heater 15 and ejected from the ejection port 13 into the heating chamber 11. The output of the circulation heater 15 is variable according to the temperature detected by the temperature sensor 11c. Thereby, the vapor | steam in the heating chamber 11 is maintained at predetermined temperature. And cooking ends when cooking time passes.

  Further, when the steam temperature raising heater 5 is stopped, saturated steam near 100 ° C. is supplied to the heating chamber 11 from the discharge port 8. Thereby, steaming cooking of the food W can be performed.

  According to this embodiment, since the inner surface of the housing 2 is coated with the silicone-based paint, the contact angle of the inner surface of the housing 2 with water is about 90 °. Thereby, compared with hydrophilic coating, adhesion of a scale is reduced and steam generation efficiency can be improved. Further, since the heat-resistant temperature is high, no toxic gas is generated even at a high temperature, and high-temperature steam can be generated without deteriorating safety.

  Further, since the inner surface of the housing 2 is painted black, the steam can also be heated by heat radiation from the inner surface of the housing 2. Therefore, the steam generation efficiency can be further improved.

  Next, a second embodiment will be described. This embodiment is configured in the same manner as the first embodiment, and a silicone-based paint, which is a non-adhesive paint, is applied to the inner surface of the housing 2 of the steam generator 1, and a hydrophilic treatment is performed thereon. Other parts are the same as those in the first embodiment.

  As in the first embodiment, the area of contact with water is reduced only by coating with a silicone-based paint as compared with the case where hydrophilic coating is performed. In the present embodiment, a hydrophilic treatment such as methylcellulose is applied to the surface of the silicone-based paint to perform a hydrophilic treatment. Thereby, a contact angle with water becomes smaller than 1st Embodiment, and it can improve steam generation efficiency. Moreover, since water repellency by the lower layer silicone-based paint is maintained, adhesion of scale can be reduced as compared with hydrophilic coating.

  In the present embodiment, the silicone-based paint is applied to the inner surface of the housing 2, but the present invention is not limited to this, and other non-adhesive paints may be used. For example, when heat resistance is not necessary, a fluorine-based paint may be applied and a hydrophilic treatment may be performed thereon.

  ADVANTAGE OF THE INVENTION According to this invention, it can utilize for the steam generator which generate | occur | produces a vapor | steam, and a heating cooker using the same.

The right view which shows the heating cooker of 1st Embodiment of this invention. The front view which shows the heating cooker of 1st Embodiment of this invention. Top surface sectional drawing which shows the heating cooker of 1st Embodiment of this invention. Front sectional drawing which shows the steam generator of the heating cooker of 1st Embodiment of this invention. AA sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steam generator 2 Housing 3 Water supply port 4 Steam generation heater 5 Steam temperature rising heater 6 Steam passage 7 Partition member 8 Discharge port 9, 11c Temperature sensor 10 Heating cooker 11 Heating chamber 12 Circulation duct 13 Jet outlet 14 Inlet port 15 Circulation Heater 16 Circulating fan 20 Water supply tank 21 Water supply pump 22 Main body housing 23 Heat shield plate 30 Magnetron 31 Waveguide 32 Antenna 33 Electrical component 34 Cooling duct 35 Cooling fan 36 Air supply duct 37 Air supply fan 38 Air supply port 40 Exhaust duct 41 Exhaust port 42 Humidity sensor

Claims (5)

  A metal housing, a water supply port for supplying water into the housing, a steam generating heater embedded in the housing for evaporating water supplied from the water supply port, and discharging steam generated by the steam generating heater A steam generator comprising a discharge port, wherein the inner surface of the housing is coated with a silicone-based paint.   The steam generator according to claim 1, wherein the silicone-based paint is black.   A metal housing, a water supply port for supplying water into the housing, a steam generating heater embedded in the housing for evaporating water supplied from the water supply port, and discharging steam generated by the steam generating heater A steam generator having a discharge port, wherein the inner surface of the housing is coated with a non-adhesive paint, and the surface of the non-adhesive paint is subjected to a hydrophilic treatment.   The steam generator according to claim 3, wherein the non-adhesive paint is made of a silicone-based paint.   The steam generator according to any one of claims 1 to 4, a heating chamber in which cooked food is stored and steam is supplied from the discharge port, a circulation fan that circulates steam in the heating chamber, and A cooking device comprising a circulation heater for heating steam circulated by a circulation fan.

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