JP4570678B2 - Steam recovery device and rice cooker - Google Patents

Description

  The present invention relates to a steam recovery device and a rice cooker, and more particularly to a steam recovery device that condenses and recovers steam and a rice cooker equipped with the steam recovery device.

Conventionally, in order to prevent the steam generated during rice cooking from being released to the periphery of the rice cooker, a rice cooker having heat exchange means for condensing the steam (same as condensation or condensate), for example, provided at the bottom of the water tank A steam recovery device that allows steam to flow into water through a hole is disclosed (see, for example, Patent Document 1).
Further, a steam recovery device is disclosed in which a steam discharge hole of a steam discharge path that enters the water tank of the heat exchange device is disposed near the bottom surface of the water tank of the heat exchange device to discharge the steam into the water ( For example, see Patent Document 2).
Furthermore, a cooking device is disclosed in which a steam pipe that penetrates the container in which the heat storage material is sealed is provided, the heat of the steam that passes through the steam pipe is transmitted to the heat storage material, and the steam is condensed (condensed) ( For example, see Patent Document 3).

Japanese Utility Model Publication No. 60-106532 (page 2-4, FIG. 1) Japanese Patent Laid-Open No. 03-231613 (second page, FIG. 1) Japanese Patent Laid-Open No. 03-182212 (page 2-3, FIG. 1)

However, the inventions disclosed in Patent Documents 1 to 3 have the following problems.
(I) Since the inventions disclosed in Patent Document 1 and Patent Document 2 inject steam into water and condense it, when injecting steam into water, bubbles (exactly, foam-like) A vapor lump) is once formed, and then the vapor in the bubbles is condensed by the surrounding water while the bubbles rise to the water surface, and the vapor is collected. Therefore, when collecting steam, there is a problem that vibration and sound (so-called “pumpy sound”) generated when bubbles are generated or disappeared.
(Ii) The invention disclosed in Patent Document 1 is provided with a check valve that prevents water from flowing out of the water tank through a hole provided at the bottom of the water tank before rice cooking, or at the bottom of the water tank. There is a problem that the passage for introducing the steam needs to be formed integrally with the water tank, and the configuration of the apparatus becomes complicated. For this reason, the manufacturing cost is increased, and cleaning after use is troublesome (an unwashed portion is generated in the bent back).

(Iii) Further, the invention disclosed in Patent Document 2 has a problem that the number of parts increases because a blower for forcibly discharging steam into water is provided.
(Iv) When the temperature difference between the water and the gas containing steam is large, when the temperature of the steam discharge path decreases and the pressure is reduced, not only does the water flow back into the steam discharge path, There is a problem that a sound having a relatively high frequency (so-called “water hammer sound”) is generated by colliding with the discharge path.

  (V) Furthermore, although the invention disclosed in Patent Document 3 eliminates the “problem that vibration and noise occur” and the “problem that water flows backward”, the configuration of the apparatus is complicated. There was a problem. For this reason, the manufacturing cost has increased, and cleaning after use has become difficult (particularly, the steam pipe cannot be separated from the container to clean the inner surface of the steam pipe).

  This invention was made in order to solve the above problems, and it aims at providing the rice cooker which can suppress the noise which generate | occur | produces at the time of vapor | steam collection | recovery, although it is a simple apparatus structure.

The steam recovery apparatus according to the present invention includes a water tank that contains cooling water for condensing steam, a dip tube disposed so that at least a tip opening is submerged in the cooling water in the water tank, and the immersion A gas pipe that communicates with the pipe and guides a gas containing vapor to the dip pipe, and a plurality of vent holes are formed, and a predetermined distance above the opening of the tip of the dip pipe and when the water tank is full And a backflow prevention plate disposed below the water surface position .

  The steam recovery apparatus according to the present invention increases the pressure on the steam generation side from the backflow prevention plate by providing a backflow prevention plate in the dip tube, and prevents water in the water tank from flowing back through the backflow prevention plate. And so-called water hammer sound can be suppressed.

Sectional drawing which shows typically the structure of the steam recovery apparatus which concerns on Embodiment 1 of this invention. Sectional drawing which shows typically the structure of the steam recovery apparatus which concerns on Embodiment 1 of this invention. The side view which shows typically the Example of the steam recovery apparatus shown in FIG. The correlation diagram which shows the result of having investigated the effect of the steam recovery apparatus shown in FIG. Sectional drawing for demonstrating the effect of the steam recovery apparatus shown in FIG. The front view which shows typically the rice cooker which concerns on Embodiment 2 of this invention. Sectional drawing which shows typically the rice cooker which concerns on Embodiment 2 of this invention.

[Embodiment 1: Steam recovery apparatus]
1 to 5 illustrate a steam recovery apparatus according to Embodiment 1 of the present invention. FIG. 1 and FIG. 2 are sectional views schematically showing the configuration, and FIG. 3 is a schematic example. FIG. 4 is a correlation diagram showing the results of investigating the operational effects, and FIG. 5 is a cross-sectional view schematically showing the operational effects. In the drawings, the same parts are denoted by the same reference numerals.

In FIG. 1, the steam recovery apparatus 1 is inserted into a water tank 60 that stores water W, and water W stored in the water tank 60, and includes a dip tube lower end opening (same as the opening) 71 at the lower end. A dip tube 70, a backflow prevention plate 73 installed at a predetermined distance from the lower end opening 71 inside the dip tube 70, and formed with a plurality of vent holes 72, and a top surface 74 of the dip tube 70. And a gas pipe 80 for guiding a gas (arrow in the figure) containing steam.
In other words, the dip tube 70 has a tubular tube upper portion 70c that forms an upper part than the backflow prevention plate 73, and a skirt in which the area of the horizontal tube inner cross section increases as it is continuously below the lower end of the dip tube upper tubular portion 70c. It has a cylindrical expansion portion 70b and a cylindrical skirt portion 70a that is continuous with the lower end of the skirt-shaped expansion portion 70b (the horizontal pipe has a constant cross-sectional area in the vertical direction). That is, the lower end of the skirt tubular portion 70 a corresponds to the dip tube lower end opening 71.

Therefore, when the steam is recovered by the steam recovery device 1, the gas containing the steam (total amount) supplied to the upper tubular portion 70c of the dip tube with respect to the atmospheric pressure applied to the water surface of the water W stored in the water tank 60. Since the pressure is lower than the atmospheric pressure, the water surface W1 in the dip tube 70 is pushed down to the dip tube lower end opening 71 side, and the gas containing the vapor is formed on the backflow prevention plate 73. It blows out to the skirt-like expanded portion 70b and the skirt tubular portion 70a via the vent hole 72, is condensed by heat exchange with the water surface W1, and is collected in the water tank 60.
At this time, a plurality of vent holes 72 are formed in the backflow prevention plate 73, so that the pressure of the dip tube upper cylindrical portion 70c is higher than the pressure of the skirt-shaped widened portion 70b, and the gas component including steam is in the downstream direction. Therefore, even when the temperature difference between the water W and the gas containing steam is large and the skirt-like expanded portion 70b and the skirt cylindrical portion 70a are suddenly depressurized, the water W is vented to the backflow prevention plate 73. 72 is pressed by the blowout from 72, and does not collide with the backflow prevention plate 73, and the upstream side of the backflow prevention plate 73 is maintained at a high pressure, so that the water W passes through the passage hole 72 and the cylindrical portion 70c on the dip tube There is no spout inside. That is, the generation of so-called water hammer sound is suppressed (this will be described in detail separately).

  Further, since the backflow prevention plate 73 is installed at a position above the dip tube lower end opening 71 by a predetermined distance, a large space (predetermined volume space) is secured in the skirt-shaped expanded portion 70b and the skirt tubular portion 70a. Therefore, steam is condensed in this space. That is, the inside of the dip tube 70 at the time of steam recovery depends on the area of the cross section of the dip tube 70 (that is, the water surface area of the water surface W1) and the distance between the water surface of the water W stored in the water tank 60 and the lower end opening 71 of the dip tube. Since the position of the water surface W1 is determined, if a backflow prevention plate 73 is provided on the upstream side with respect to the water surface W1 in the dip tube 70 at the time of steam recovery, the water hammer sound can be suppressed and the water surface W1 can be further downstream. If configured so that the lower end opening 71 of the dip tube comes, the vapor does not overflow from the lower end opening 71 of the dip tube, and the generation of so-called poppy sounds is suppressed (this will be described in detail separately).

  Further, since the water W in the water tank 60 increases as the steam is recovered, the backflow prevention plate 73 is full when the water tank 60 is full (water The water hammer noise can be suppressed until the water tank 60 becomes full by installing the water tank 60 at a position upstream of the position of the water surface W1. Further, since the position of the water surface W1 in the dip tube 70 at the time of steam recovery varies depending on the pressure of the gas containing the supplied steam, the area of the cross-section of the dip tube 70 (that is, the surface of the water surface W1) in accordance with the pressure condition. Water surface area) or the distance between the water surface of the water W stored in the water tank 60 and the lower end opening 71 of the dip tube, or a structure is provided in which the water surface W1 area in the dip tube 70 is reduced when the gas pressure is increased. Thus, whatever the gas containing the supplied steam is, it is possible to recover the steam while suppressing the generation of water hammer sound and pop sound.

  Further, for example, in the situation where impurities such as dust are mixed with the steam, if there is only one vent hole 72, the vent hole 72 may be clogged by the impurities, and the steam cannot reach the water W and cannot recover the steam. However, by forming a plurality of vent holes 72 in the backflow prevention plate 73, even if one vent hole 72 is clogged with impurities, the other vent holes 72 remain open without impairing their functionality. In addition, it is possible to continuously suppress the generation of sound accompanying steam recovery.

Next, a modified example of the dip tube 70 described above will be described.
2A, the steam recovery apparatus 2 removes the skirt cylindrical portion 70a in the steam recovery apparatus 1 to form a dip tube lower end opening 71 of the skirt-shaped expanded portion 70b.
In FIG. 2B, the steam recovery device 3 is a trumpet-shaped portion that smoothly expands the diameter of all of the skirt tubular portion 70a, the skirt-shaped expanded portion 70b, and the dip tube upper tubular portion 70c in the steam recovery device 1. 70d (same as morning glory).
In FIG. 2 (c), the steam recovery device 4 is configured to remove the skirt-shaped expanded portion 70b in the steam recovery device 1 to form the dip tube lower end opening 71 of the skirt tubular portion 70a.

  1 and FIG. 2, the dip tube 70 is formed so that the area of the partial cross-section of the dip tube 70 is increased. However, the area of the cross-section of the dip tube 70 is uniformly set to a predetermined water surface. You may comprise more than an area. However, the volume of the dip tube 70 is smaller if the area of the cross section in the tube is partially increased as in the case of the dip tube 70 described in FIGS. 1 and 2, so that the volume of the same water tank 60 is larger. Water W can be stored. Therefore, it is possible to recover more steam even with the same volume of the water tank 60, and to achieve a compact structure of the water tank 60 without reducing the amount of recoverable steam.

Further, as in the case of the dip tube 70 of FIGS. 1 and 2, the dip tube lower end opening 71 is configured to have the largest cross-sectional area in the tube, thereby facilitating cleaning of the dip tube 70 inside. can get.
Further, as shown in FIGS. 2 (a) and 2 (b), the dip tube 70 is formed in a compact manner by forming the dip tube 70 so that the cross-sectional area of the dip tube 70 gradually increases from upstream to downstream. The effect that can be done.
Further, the present invention does not limit the shape of the steam recovery apparatuses 1 to 3 in plan view, and for example, a substantially circular dip tube 70 may be inserted into a substantially rectangular water tank 60.

Further, the backflow prevention plate 73 is not limited to the one arranged at the boundary between the skirt-like expanded portion 70b and the dip tube upper tubular portion 70c, and the water surface W1 in the dip tube 70 flows back during steam recovery. If it is configured to be between the prevention plate 73 and the lower end opening 71 of the dip tube, it may be disposed at any position of the dip tube 70. Further, the gas pipe 80 is not limited to the one installed on the top surface 24 of the dip tube 70 (the same as the top surface of the dip tube upper cylindrical portion 70c), and the gas pipe 80 flows backward on the side surface of the dip tube upper cylindrical portion 70c. It may be installed closer to the top surface 74 than the prevention plate 73.
Further, in the case of the one having the above-described effects (the pressure of the upper tubular portion 70c of the dip tube can be increased and the backflow of the water W can be prevented), for example, a mesh or a honeycomb structure is formed. It can replace with the made backflow prevention board 73 and can be installed. Further, instead of providing the backflow prevention plate 73 separately, the same effect as that of the backflow prevention plate 73 may be obtained by narrowing a part of the dip tube 70 to reduce the area of the cross section in the tube.

(Example)
FIG. 3 is a side view schematically showing an embodiment of the steam recovery apparatus 2. In FIG. 3, the skirt-like expanded portion 70b is conical, the diameter of the lower end opening 71 of the dip tube being 40 to 50 mm (1260 to 1960 mm 2), and the height of the skirt-like expanded portion 70b is 20 to 30 mm. The backflow prevention plate 73 disposed at the boundary between the skirt-like expanded portion 70b and the dip tube upper cylindrical portion 70c has a diameter of 18 to 20 mm and 6 to 9 vent holes 72 having a diameter of 2 to 3 mm. And the internal diameter of the dip tube upper cylindrical part 70c is 18-20 mm.
In addition, when the opening area of the skirt cylindrical part 71a in which the water surface W1 is located is small (the water surface area is small), the contact area between the steam blown to the skirt-like expanded part 70b and the water surface W1 is insufficient. If it does so, the vapor | steam condensation speed | rate will not be in time with respect to the generation | occurrence | production speed | velocity | rate of vapor | steam, and a part of this vapor | steam and air will penetrate | invade into the water W as a bubble (without condensing), and will cause the said poppy sound.
On the other hand, when there is no backflow prevention plate 73 or the inner diameter of the vent hole 72 is not appropriate, an increase in pressure in the dip tube upper cylindrical portion 70c is not expected. Then, when rapid vapor condensation occurs in the dip tube upper cylindrical portion 70c, the water W collides with the backflow prevention plate 73 or passes through the vent hole 72 and enters the dip tube upper cylindrical portion 70c. It causes the water hammer sound.

FIG. 4 is a result of investigating the operational effects of the steam recovery apparatus 2. FIG. 4A is a correlation diagram showing the relationship between the area of the dip tube lower end opening 71 and noise, and FIG. ) Is a correlation diagram showing the relationship between the distance between the dip tube lower end opening 71 and the backflow prevention plate 73 and noise.
4 (a) and 4 (b), it is shown that the water surface area of the skirt portion should be 1800 mm 2 or more and the skirt height should be 20 mm or more in order to reduce the noise below the allowable range Lc [dB]. Yes. FIG. 4 shows the case where the inner diameter of the vent hole 72 is 2 mm, but the same applies to the case where the inner diameter of the vent hole 72 is 3 mm.

FIG. 5 is a cross-sectional view in side view schematically showing the operational effects of the dip tube 70 of the steam recovery apparatus 2. Here, the shape of the dip tube in FIG. 1 will be described.
In FIG. 5A, if the number of the vent holes 72 is too small, or the inner diameter of the vent holes 72 is too small, the momentum of the steam ejected through the vent holes 72 becomes strong, and the steam jet (arrow) is generated. It will enter the water surface W1 and generate a “rush sound”.
In FIG. 5B, when the height of the skirt tubular portion 70a is too low, steam (arrow) ejected through the vent hole 72 enters the water surface W1 and generates a “rush sound”. .
In FIG. 5C, when the quantity and inner diameter of the air holes 72, the height of the skirt tubular portion 70a, and the water surface area of the water surface W1 in the skirt tubular portion 70a are appropriately set, The sound (rush sound) at the time of entry between the arrow) and the water surface W1 is completely absent.

  That is, the backflow prevention plate 73 is adjusted by adjusting the area of the water surface W1 in the dip tube 70, the distance between the water surface W1 and the backflow prevention plate 73, and the opening area and number of the vent holes 72 formed in the backflow prevention plate 73. By adjusting so that the steam ejected from the air vent 72 does not directly enter the water surface W1 in the dip tube 70, it is possible to prevent the “rush sound” generated when the steam enters the water W. . For example, if the generation amount of steam can be suppressed, the “rush sound” may be prevented by adjusting the generation of steam (mostly reducing the generation of steam).

[Embodiment 2: Rice cooker]
(rice cooker)
6 and 7 illustrate a rice cooker according to Embodiment 2 of the present invention. FIG. 6 is a front view, FIG. 7A is a schematic cross-sectional view in side view, and FIG. (B) is a sectional view schematically showing a plan view.
6 and 7, the rice cooker 100 includes a main body 20 having an open top, an inner pot 30 that is installed in the main body 20 and accommodates the rice R to be cooked, and is pivotally supported by the main body 20. The lid 10 covers the upper opening of the pot 30 so that it can be opened and closed, the heating means 21 for heating the cooked rice R, and the control means (not shown) for controlling the heating means 21.
Furthermore, when the cooked rice R is heated (more precisely, when the water X is also heated together with the cooked rice R), the air A discharged from the inner pot 30 is induced and the cooked rice R and the water X are used. It has a gas pipe 40 for inducing the generated steam V, and a steam recovery apparatus 1 (see Embodiment 1) into which air A and steam V induced by the gas pipe 40 are injected.

(Gas pipe)
The gas pipe 40 is detachably provided on the lid body 10, and communicates with the dip pipe 70 of the steam recovery apparatus 1 configured integrally with the water tank lid 62 of the water tank 60 by closing the lid body 10. It has become. In the second embodiment, the water tank lid 62 and the dip pipe 70 are integrally formed. However, the present invention is not limited to this, and the gas pipe 40 and the dip pipe 70 only need to communicate with each other. 70 may be configured as a separate body, and the gas pipe 40 and the dip pipe 70 may communicate with each other through a hole opened in the water tank lid 62. A sealing means 41 (for example, an O-ring) is provided at a connection portion between the gas pipe 40 and the dip pipe 70 to prevent the vapor V from leaking. As a result, even if the gas pipe 40 becomes dirty, it can be easily cleaned, and the inner pan 30 can be accessed with the gas pipe 40 installed, which greatly improves the convenience for the user. be able to.
Note that the shape and the like of the gas pipe 40 are not limited to those shown in the figure, and a “sticking means”, a gas release valve, and the like may be appropriately installed.

(water tank)
In FIG. 7, the water tank 60 includes a box-shaped water tank main body 61 opened at the top, a water tank lid (corresponding to a water tank top plate) 62 that covers the opening of the water tank main body 61, a water tank lid, It has a dip tube 70 configured integrally and a water tank clue 64 formed on the water tank front surface 63 of the water tank main body 61. And when the water tank 60 is installed in the opening part 22 of the main body 20, since the main body front surface 21 and the water tank front surface 63 form a substantially identical surface, the design property is ensured. The shape of the water tank clue 64 is not limited to that shown in the figure. Further, since the dip tube 70 is configured to be removable from the water tank 60, it can be easily cleaned. Further, since the water tank 60 itself serving as the steam recovery device can be taken out from the main body 20, it is possible to easily exchange the cooling water stored in the water tank 60, or to easily clean the water tank 60 itself. It is done.

  The water tank 60 is formed of a permeable material (for example, a resin material such as ABS or PP), and has a configuration in which the amount of water stored in the water tank 60 can be grasped at a glance. The dip tube 70 is made of a highly heat conductive material (for example, a metal such as copper, copper alloy, aluminum, aluminum alloy, etc.), and increases the heat exchange rate between the dip tube 70 and the water W in the water tank 60. , Promote the condensation of steam V. Thereby, even if the contact area between the steam V and the water surface W1 is reduced, a sufficient condensation rate can be obtained, so that the dip tube 70 can be made compact, and therefore the amount of water W that can be stored in the water tank 60. It can be made compact while maintaining.

(Steam treatment)
When rice cooking is started, the air A and the generated steam V in the inner pot 30 induced by the gas pipe 40 are injected into the steam recovery apparatus 1. The injected steam V is cooled by the water W in the water tank 60 and condensed (condensed).
At this time, the contact area between the steam V and the water surface W1 is increased by the skirt-like expanded portion 70b, and the steam V is condensed while maintaining the water surface W1 in the immersing tube 70, thereby preventing the occurrence of the popping noise. In addition, by providing the backflow prevention plate 73, even if rapid condensation occurs, the water W collides with the backflow prevention plate 73 or passes through the backflow prevention plate 73 and enters the upper tubular portion 70c of the dip tube. Therefore, the generation of the water hammer sound is prevented, and further, the backflow prevention plate 73 is provided at an appropriate position upstream of the water surface W1 to prevent the generation of the rush sound due to the steam jet entering the water surface. Can do.

Therefore, the rice cooker 100 can reduce the noise generated with the steam recovery during the rice cooking than the rice cooker using the conventional steam recovery technology.
In place of the steam recovery apparatus 1, the steam recovery apparatus 2 or 3 may be installed. Moreover, the arrangement position and installation method of the water tank 60 are not limited to this.

  From the above, since the steam recovery apparatus of the present invention can silently recover steam in water, various steam recovery apparatuses (condensation apparatuses) for home use or business use, of course, rice cookers and various cookers, It can be widely used as a steam recovery device (condensation device) in various devices for purposes other than cooking rice or cooking.

  1: Steam recovery device (Embodiment 1), 2: Steam recovery device (Embodiment 1), 3: Steam recovery device (Embodiment 1), 10: Lid, 20: Main body, 21: Heating means, 22: Opening part, 30: Inner pot, 40: Gas pipe, 41: Sealing means, 60: Water tank, 61: Water tank main body, 63: Water tank front, 70: Dip pipe, 70a: Skirt tubular part, 70b : Skirt-like spreading part, 70c: dip tube upper cylindrical part, 71: dip tube lower end opening, 72: vent hole, 73: backflow prevention plate, 74: top surface, 100: rice cooker (Embodiment 2).

Claims (12)

A water tank containing cooling water for condensing steam;
A dip tube disposed so that at least the tip opening is submerged in the cooling water in the water tank;
A gas pipe that communicates with the dip pipe and guides a gas containing vapor to the dip pipe;
A plurality of vent holes, and a backflow prevention plate disposed at a predetermined distance above the opening of the tip of the dip pipe and below a water surface position when the water tank is full. Steam recovery equipment. The backflow prevention plate is
2. The device according to claim 1, wherein when the gas containing the vapor is guided into the dip tube, a water surface in the dip tube is positioned between the backflow prevention plate and a tip opening of the dip tube. Steam recovery equipment. The dip tube is
When the gas containing the vapor is guided into the dip tube, the cross-sectional area in the tube of the dip tube is partially enlarged so that the water surface in the dip tube secures a predetermined water surface area. The steam recovery apparatus according to claim 1 or 2 . The dip tube is
The steam recovery device according to claim 3 , wherein the cross-sectional area in the pipe is larger on the downstream side than the upstream side of the backflow prevention plate. The dip tube is
The steam recovery apparatus according to claim 3, wherein a cross-sectional area inside the tube of the tip opening of the dip tube is the largest. The cross-sectional area of the dip tube is:
It forms so that it may become large gradually toward the front-end | tip opening part of the said dip tube. The steam recovery apparatus in any one of the Claims 3 thru | or 5 characterized by the above-mentioned. Depending on the opening area and number of the vents,
The steam recovery apparatus according to any one of claims 1 to 6 , wherein a passage amount of the gas containing the steam is adjusted to an appropriate passage amount . The water surface area in the dip tube, the distance between the water surface and the backflow prevention plate, the opening area and the number of the air holes are adjusted so that the steam ejected from the vent hole does not directly enter the water surface in the dip tube. The steam recovery apparatus according to any one of claims 1 to 7 , wherein: An inner pot for storing cooked rice,
Heating means for heating the cooked rice;
A main body on which the inner pot is mounted and equipped with the heating means;
A lid that is installed on the main body and covers the upper opening of the inner hook so as to be freely opened and closed;
The steam recovery apparatus according to any one of claims 1 to 8 installed in the main body,
Have
The said gas pipe induces the vapor | steam which arises from the air discharged | emitted from the said inner pot, and the said to-be-cooked rice when the to-be-cooked rice is heated. The gas pipe is
The rice cooker according to claim 9 , wherein the rice cooker is disposed in the lid and is detachably connected to the dip tube. The rice cooker according to claim 9 or 10, wherein the dip tube is detachably formed from the water tank. The rice steamer according to any one of claims 9 to 11 , wherein the steam recovery device is detachably installed on the main body.

Images