CA3034461A1

CA3034461A1 - Cooking apparatus with water circulation system

Info

Publication number: CA3034461A1
Application number: CA3034461A
Authority: CA
Inventors: Chao Ma; Jean-Marie Bourgeois-Jacquet
Original assignee: SEB SA
Current assignee: SEB SA
Priority date: 2016-08-30
Filing date: 2017-08-04
Publication date: 2018-03-08
Also published as: EP3506805A1; WO2018041535A1; CN206213817U; AU2017320373A1

Abstract

Cooking apparatus, wherein said cooking apparatus comprises internal pot (10), heating means (80), steamer (20) that is housed within said internal pot (10), as well as a water circulation system, which is connected with said internal pot (10) and steamer (20) to channel water from internal pot (10) to steamer (20); said heating means (80) is used to heat up said internal pot (10).

Description

COOKING APPARATUS WITH WATER CIRCULATION SYSTEM
The present invention relates to the field of cooking equipment and in particular to a cooking apparatus.
To cook rice with low Glycemic index, the electric rice cookers of the prior art are equipped with a water tank, and water is pumped from the water tank into the io internal pot of the rice cooker. The base of the internal pot is equipped with a water discharge hole. During rice washing, water is sprayed downwards and towards the interior of the internal pot to wash the rice contained within the pot.
The water then flows out from the water discharge hole at the base of the internal pot into the water drain at the bottom of the pot. A portion of the starch and sugar content of the rice is washed out together with the water. After rice washing and soaking are completed, the water discharge hole at the base of the internal pot will be closed. Thereafter, a specific amount of water will be added into the internal pot to cook the rice.
The electric rice cookers of the prior art must be equipped with a water tank, water discharge hole, water drain and other structures, which makes them rather complex and difficult to seal and wash.
The main object of the present invention is to provide a cooking apparatus that is .. structurally simple and yet able to produce cooked rice with low sugar content.
To achieve the above object, the present invention provides a cooking apparatus, which comprises an internal pot, a heating means, a steamer that is housed within the internal pot, as well as a water circulation system, which is connected with the internal pot and steamer to channel water from the internal pot to the steamer.
The heating means is used to heat up the internal pot.

2 Further, the water circulation system comprises a flow directing conduit, and one end of the flow directing conduit is disposed within the internal pot, while the other end extends into the steamer. The external wall of the steamer is engaged with the internal pot in a sealed engagement.
Further, the flow directing conduit comprises: a steamer suction tube, which is connected with the steamer; a water discharge tube, which is connected to both the steamer suction tube and the steamer.
io Further, the steamer suction tube and the steamer is integrated in one unit.
Further, the cooking apparatus also comprises: an external housing, wherein both the internal pot and heating means are disposed within the external housing;
a top cover, which is disposed on the external housing, and the water discharge tube is disposed on the top cover.
Further, the water circulation system comprises a suction pump that is provided on the flow directing conduit, and the suction pump is used to draw water from the internal pot into the steamer.
Further, the internal diameter of the steamer suction tube is at least 0.5mm and at most 20mm.
Further, the internal diameter of the steamer suction tube is at least 1.5mm and at most 12mm.
Further, the water drainage hole is disposed on the bottom and/or side wall of the steamer.
Further, the bottom wall of the steamer protrudes upwards such that it is higher at the center and lower at the edges.

3 Further, the end of the flow directing conduit that extends into the steamer is equipped with a nozzle.
Further, the end of the flow directing conduit that extends into the steamer is equipped with a nozzle.
Further, there is a height difference of H1 between the lowest points on the bottom walls of the internal pot and steamer, and H1 is at least 0.1H and at most 0.8H, where H is the height of the internal pot.
lo Further, there is a height difference of H2 between the lowest point of the bottom wall of the steamer and the mouth of the internal pot, and H2 is at least 0.1H
and at most 0.8H, where H is the height of the internal pot.
The cooking apparatus according to the present invention comprises an internal pot, a heating means, a steamer that is housed within the internal pot, as well as a water circulation system, which is connected with the internal pot and steamer.
The heating means is used to heat up the internal pot. Hence, the cooking apparatus according to the present invention does not require a water discharge hole, water drain or other related structures, can have a simple structure. By separating rice cooking and steaming processes using the steamer, the starch and sugar contents of the rice are reduced when they are washed from the rice and enter into the rice water in the internal pot. This lowers the sugar content of the cooked rice and produces low glycemic index rice. Further, water is recycled and reused by producing steam to be used for steaming the rice from the water that was used to wash the rice.
The drawings constitute a portion of the Description for further understanding of the present invention. These drawings illustrate the embodiments of the present invention and explain the principle of the present invention together with the Description. They are not intended to limit the scope of the utility model. In the drawings:

4 FIG. 1 is a schematic structural view of a cooking apparatus according to the first embodiment of the present invention;
FIG. 2 illustrates the relative positions of the steamer and the internal pot from FIG. 1, before the internal pot is filled with water;
FIG. 3 illustrates the relative positions of the internal pot, steamer, flow directing conduit and suction pump from FIG. 1, before rice comes into contact with water;
io FIG. 4 illustrates the relative positions of the internal pot, steamer, flow directing conduit and suction pump from FIG. 1 during the rice washing step;
FIG. 5 is a schematic structural view of a cooking apparatus according to the second embodiment of the present invention;
FIG. 6 illustrates the relative positions of the internal pot, steamer and flow directing conduit in FIG. 5 before the rice washing step and before rice has come into contact with water;
FIG. 7 illustrates the relative positions of the internal pot, steamer and flow directing conduit in FIG. 5 during the rice washing step;
FIG. 8 is a flowchart depicting the process of cooking rice using the cooking apparatus in FIG. 1; and FIG. 9 is a flowchart depicting the process of cooking rice using the cooking apparatus in FIG. 5.
Wherein the above-mentioned figures comprise following reference numbers:
10. Internal pot; 20. Steamer; 21. Water drainage hole; 22. Bearing cavity;
23.
Protruding part; 30. Flow directing conduit; 31. Steamer suction tube; 32.
Water

5 PCT/EP2017/069866 discharge tube; 33. Nozzle; 40. Suction pump; 50. External housing; 60. Top cover; 70. First sealing ring; 80. Heating means.
It should be noted that the particular features of any specific embodiment may be 5 combined in any suitable manner with one or more other specific embodiments.
Representative embodiments of the present invention are explained hereinafter with reference to the accompanying drawings.
It is to be understood that the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
In the present invention, terms indicating orientation or direction, such as "up, down, top or bottom" are not intended to be absolute terms unless the context requires or indicates otherwise. These terms will normally refer to orientations shown in the drawings. Similarly, to facilitate understanding and description, "internal" and "external" refer to a positioning with respect to the boundary of the part itself. The above terms are not intended to restrict the scope of this invention.
The cooking apparatus of the present invention is structurally simple and able to fulfil the object of lowering the Glycemic index value of the cooked rice.
As shown in FIG. 1 to 4, the cooking apparatus of the first preferred embodiment of the present invention comprises internal pot 10, heating means 80, a water circulation system connected to internal pot 10 and steamer 20, and a steamer 20 housed within internal pot 10. Heating means 80 heats up internal pot 10.
In this way, compared to cooking apparatuses of the prior art that requires a water tank, water outlet, drainage pipe, the cooking apparatus according to the present invention is equipped with a water circulation system to circulate water between

6 internal pot 10 and steamer 20, which prevents wastage of water resources. As the cooking apparatus according to the present invention is not equipped with a water tank or drainage pipe, the apparatus is structurally simpler and of smaller size, and is hence easier to use and clean. Furthermore, the cooking apparatus according to the present invention does not have the problems associated with cooking apparatuses of the prior art, such as ensuring proper sealing of the water outlet, difficulty in washing the internal pot, difficulty in placing the internal pot during usage, etc.
io As shown in FIG. 1 to 4, in the first preferred embodiment of the present invention, the bottom wall of steamer 20 has a protruding part 23 that protrudes towards the inside of steamer 20. Specifically, the center part of the bottom wall of steamer 20 protrudes upwards such that the center of the bottom wall of steamer 20 is higher at its center and lower at the edges. Thus, during rice steaming, the water rising in internal pot 10 can be prevented from coming into contact with the rice, and rice is cooked through steaming to produce rice of better taste.
Optionally, steamer 20 can be cylindrical, pyramidal, hexahedral or other shapes.
As shown in FIG. 2, to ensure that the bubbling rice milk in internal pot 10 does not come into contact with the rice during the rice steaming process, the lowest point of the bottom wall of internal pot 10 is at a distance H1 from the lowest point of the bottom wall of steamer 20, and H1 is at least 0.1H and at most 0.8H, where H is the height of the internal pot 10, i.e. the distance between the bottom wall and mouth of internal pot 10.
As shown in FIG. 2, the distance between the lowest point of the bottom wall of steamer 20 and the mouth of internal pot 10 is H2, and H2 is at least 0.1H and at most 0.8H, where H is the height of internal pot 10.
As shown in FIG. 1 and 2, steamer 20 has a water drainage hole 21 and bearing cavity 22. After rice washing, water flows into internal pot 10 via water drainage

7 hole 21.
Specifically, water drainage hole 21 is a plurality of holes. Said plurality of water drainage holes 21 are located at the bottom wall of steamer 20.
Preferably, the plurality of water drainage holes 21 are all located on protruding part 23. Of course, in alternative embodiments not shown in the figures, the plurality of water drainage holes 21 can also be located on the side wall of steamer 20.
Optionally, to ensure that the rice in steamer 20 will not escape through the water drainage holes 21, the cross-section of each water drainage hole 21 can be circular, elliptical, rectangular or polygonal.
When water drainage hole 21 takes the shape of an irregular polygon, the largest dimension of water drainage hole 21 is at least 0.5mm and at most 30mm.
Optionally, the largest dimension of the irregular polygonal water drainage hole 21 is at least 0.8mm and at most 20mm.
As shown in FIG. 1 to 4, the water circulation system comprises flow directing conduit 30 and suction pump 40 disposed on the flow directing conduit 30. In this embodiment of the cooking apparatus, suction pump 40 is used to push water from internal pot 10 smoothly into steamer 20 (i.e. bearing cavity 22) to wash the rice contained within steamer 20 and to let the rice to absorb water.
As shown in FIG. 2 to 4, the external wall of steamer 20 is connected to the mouth of internal pot 10 in a sealed connection. Of course, in this specific embodiment, steamer 20 and internal pot 10 need not be connected through a sealed structure.
In this set-up, one end of flow directing conduit 30 is located within internal pot 10 but outside steamer 20, and the other end of flow directing conduit 30 extends

8 into steamer 20.
Specifically, as shown in FIG. 2 and 4, flow directing conduit 30 comprises a steamer suction tube 31 and water discharge tube 32 that is connected to steamer suction tube 31.
To facilitate assembly, flow directing conduit 30 and steamer suction tube 31 can be integrated with steamer 20.
io As shown in FIG. 3 and 4, the end of water discharge tube 32 that points towards steamer 20 is fitted with nozzle 33, so as to spray water evenly on the rice contained within steamer 20. This ensures that all rice grains can absorb an adequate amount of water.
As shown in FIG. 1, the cooking apparatus further comprises external housing and top cover 60, and internal pot 10 is disposed within external housing 50;
top cover 60 is fitted on top of external housing 50. Water discharge tube 32 and suction pump 40 are fitted on top cover 60.
The cooking apparatus described above is an electric rice cooker, but can also be a microwave, electric slow cooker or electric pressure cooker.
Optionally, heating means 80 is a heating device selected from the group comprising a heating plate, heating tube, IH electromagnetic heating device and heating film.
It should be noted that before using the cooking apparatus according to the present invention, rice must be added to bearing cavity 22 of steamer 20, and water must be added to internal pot 10.
As shown in FIG. 5 to 7, in a cooking apparatus of another structure (i.e. the second preferred embodiment), the water circulation system differs from that in

9 the first preferred embodiment in that no suction pump 40 is provided on flow directing conduit 30.
Furthermore, the external wall of steamer 20 is connected to the mouth of internal pot 10 in a sealed connection. Specifically, the external wall of steamer 20 is connected to the mouth of internal pot 10 in a connection sealed with first sealing ring 70. This effectively ensures that when pressure within the separating cavity between internal pot 10 and steamer 20 rises, steam can push water smoothly into steamer 20 through flow directing conduit 30, and steam is prevented from io escaping through the top of steamer 20 and the mouth of internal pot 10.
It should be noted that to ensure that the steam can push water smoothly into steamer 20 through steamer suction tube 31 and water discharge tube 32 after the pressure in the separating cavity between internal pot 10 and steamer 20 rises, the internal diameter of steamer suction tube 31 should be at least 0.5mm and at most 20mm.
Further optionally, the internal diameter of steamer suction tube 31 is at least 1.5mm and at most 12mm.
As shown in FIG. 8, the present invention provides a method for cooking rice using a cooking apparatus, wherein different steps and elements of the flowchart are represented by following references:

Si: Place a certain amount of water into the internal pot S2: Put in the steamer, and put rice into steamer S3: Rice washing, water absorption S4: Water in the internal pot is heated and boiled, and this status is maintained up to the third preset time t3 S5: Water in the internal pot stops getting heated, and the contents of the pot is held up to the fourth preset time t4 S6: Water in the internal pot is heated and boiled, and this status is maintained up to the fifth preset time t5 S7: Water in the internal pot stops getting heated, and the contents of the pot is held up to the sixth preset time t6 S8: Rice steaming and cooking is completed S9: Water is heated up to the specified temperature Ti, and the status is maintained up to the first preset time ti El: Suction pump a: Closed E2: PCB A: Activated E3: Heating means b: Not powered Cl : Maintained to second B: powered preset time t2 C2: Cycle repeated Ni times C3: Cycle repeated N2 times In this method, the cooking apparatus can be controlled using the method described in the first specific embodiment, and the method for cooking rice using the cooking apparatus comprises the following steps: the rice washing step in 5 which water is drawn from internal pot 10 into steamer 20 using the water circulation system to wash the rice contained within steamer 20, and thereafter, the water is directed into internal pot 10; the rice steaming step in which heating means 80 heats up internal pot 10.
io Hence, water is recycled and reused by producing steam to be used for steaming the rice from the water that was used to wash the rice. Additionally by separating the cooking and steaming processes using steamer 20, the starch and sugar contents of the rice are reduced when they are lost from the rice and enter the rice water in internal pot 10. This lowers the sugar content of the cooked rice and produces low glycemic index rice.
Before proceeding with rice washing, a certain amount of rice must be placed within steamer 20, and a certain amount of water must be placed into internal pot

10. The cooking apparatus then begins to operate at this point, with suction pump 40 being activated to create a water circulation loop within the cooking apparatus by its suction action on the water in internal pot 10. The circulated water is sprayed out from nozzle 33 located at the top of internal pot 10 and falls onto the rice contained within steamer 20. This washes the rice from top down and the io rice also absorbs water in this process.
Optionally, during the rice washing step, rice washing is sustained up to the second preset time t2, and t2 is at least 180s and at most 2400s.
Further optionally, in the rice washing step, the second preset time t2 is at least 300s and at most 1800s.
It should be noted that a preheating step is performed between said rice washing and rice steaming steps, and said preheating step comprises heating the water in internal pot 10 to a first preset temperature Ti and maintaining this up to a first preset time t1, after which, the operation of the water circulation system is stopped.
Optionally, during the preheating step, the first preset temperature Ti is at least 10 C and at most 100 C, and the first preset time t1 is at least 20s and at most 600s.
Further optionally, the first preset temperature Ti is at least 50 C C and at most 95 C, and the first preset time t1 is at least 30s and at most 400s.
To improve the taste of the cooked rice and to enhance the performance of the cooking apparatus, the entire rice steaming step is divided into the preliminary rice steaming stage and the final rice steaming stage according to sequence in time.
It should be noted that during the preliminary rice steaming stage, heating means 80 heats up internal pot 10 to the third preset time t3, after which, heating means 80 stops operating and rice steaming is allowed to continue up to the fourth preset time t4, and the preliminary rice steaming stage is repeated Ni times. Hence, through intermittent heating, this control method ensures that sufficient steam is produced by cooking apparatus to keep the rice in a state of high-temperature io steaming, and boiling water will not mix with the foam from the rice milk and is prevented from rising and coming into contact with the rice. The requirements on the third preset time t3 is therefore comparatively stringent. Additionally, water is prevented from overheating and producing excessive amounts of steam that could lead to leakage of water. Spillage is thereby prevented and energy conserved.
Optionally, t3 is at least 3 seconds and at most 130 seconds, t4 is at least 3 seconds and at most 130 seconds, and Ni is at least 2 and at most 100.
.. Further optionally, Ni is at least 4 and at most 80.
It should be noted that in the final rice steaming stage, as rice steaming progresses, water is constantly evaporated into steam, and the concentration of the rice milk in internal pot 10 increases continuously. Under heating, the rice milk is more prone to emerging from bearing cavity 22 of steamer 20 and coming into contact with the rice. This will affect the moisture content of the rice and compromise the GI reduction effect. Hence, after heating means 80 heats up internal pot 10 to the fifth preset time t5, the operation of heating means 80 must be stopped and the state must be maintained up to the sixth preset time t6, to prevent generation of excessive amounts of steam, which can lead to water leakage and the rice milk foam rising and coming into contact with the rice.

Optionally, t5 is at least 3 seconds and at most 130 seconds, t6 is at least 3 seconds and at most 130 seconds, and N2 is at least 2 and at most 100.
Further optionally, N2 is at least 4 and at most 80.
In this specific embodiment, when the cooking apparatus is in the rice steaming step, the on and off times of heating means 80 need not be entirely regular.
This means that the heating duration and stopping duration of heating means 80 can be optimized based on the progress of cooking, such that these durations vary between cycles.
Table 1 shows the specific method used in the rice steaming step of the cooking apparatus:
Table 1 Rice steaming step No. of times Preliminary rice steaming stage ..
Final rice steaming stage t3 (seconds) t4 (seconds) t5 (seconds) t6 (seconds) Controlling the operation of the cooking apparatus using the method described above allows the cooking apparatus to have a simpler structure, and produces cooked rice with low glycemic index value, which will in turn increase the level of satisfaction among the users.
As shown in FIG. 9, the present invention further provides a second method for cooking rice using the cooking apparatus, wherein different steps and elements of the flowchart are represented by following references:
Si: Place a certain amount of water into the internal pot S2: Put in the steamer, and put rice into steamer S3: Rice washing, water absorption S4: Water in the internal pot is heated and boiled, and this status is maintained up to the third preset time t3 S5: Water in the internal pot stops getting heated, and the contents of the pot is held up to the fourth preset time t4 S6: Water in the internal pot is heated and boiled, and this status is maintained up to the fifth preset time t5 S7: Water in the internal pot stops getting heated, and the contents of the pot is held up to the sixth preset time t6 S8: Rice steaming and cooking is completed S9: Water is heated up to the specified temperature Ti, and the status is maintained up to the first preset time ti S10: Water is maintained at a constant temperature T2 S11: Water is heated up to the second preset temperature T2 El: Suction pump a: Closed E2: PCB A: Activated E3: Heating means b: Not powered Cl : Maintained to second B: powered preset time t2 C2: Cycle repeated Ni times C3: Cycle repeated N2 times io For this second method, two different treatments that differ in the sequence of the preheating and rice washing steps are provided.

The first treatment comprises: performing a preheating step before rice washing, wherein water in internal pot 10 is heated to a second preset temperature T2, and thereafter, the water circulation system of the rice washing step is activated, and this state is maintained this up to the second preset time t2.

The second type of treatment comprises: heating up the water contained within internal pot 10 using heating means 80 as soon as the rice washing step is activated, and when temperature of the water reaches a second preset temperature T2, the rice washing step continues circulating up to a second preset io time t2.
In this way, by using water of a specific temperature to wash the rice and for water absorption, a substantial amount of starch and sugar can be washed away from the rice, and cooked rice with low Glycemic index (sugar) is produced.
Optionally, in both treatments described above, during the preheating step, T2 is at least 30 C and at most 95 C, and the second preset time t2 is at least 180s and at most 2400s.
Further optionally, T2 is at least 60 C and at most 80 C, and the second preset time t2 is at least 300s and at most 1800s.
The rice washing step can be followed by the rice steaming step. The rice steaming step in this method is identical to that in the first method, and hence the description will not be repeated here.
The above are merely preferred embodiments, and are not intended to limit the present invention.

Claims

1. Cooking apparatus, wherein said cooking apparatus comprises internal pot (10), heating means (80), steamer (20) that is housed within said internal pot (10), as well as a water circulation system, which is connected with said internal pot (10) and steamer (20) to channel water from internal pot (10) to steamer (20); said heating means (80) is used to heat up said internal pot (10).

2. Cooking apparatus according to Claim 1, wherein said water circulation system comprises flow directing conduit (30), and one end of said flow directing conduit (30) is disposed within internal pot (10), and the other end of said flow directing conduit (30) extends into said steamer (20);
the external wall of said steamer (20) is engaged with said internal pot (10) in a sealed engagement.

3. Cooking apparatus according to Claim 2, wherein said flow directing conduit (30) comprises:
steamer suction tube (31), which is connected to steamer (20);
water discharge tube (32), which is connected to both said steamer suction tube (31) and said steamer (20).

4. Cooking apparatus according to Claim 3, wherein said steamer suction tube (31) and said steamer (20) are integrated in one unit.

5. Cooking apparatus according to Claim 3, wherein said cooking apparatus further comprises:
external housing (50), and said internal pot (10) and said heating means (80) are both housed within said external housing (50);
top cover (60), which is disposed on said external housing (50), and said water discharge tube (32) is disposed on said top cover (60).

6. Cooking apparatus according to any of the Claims 2 to 5, wherein said water circulation system comprises suction pump (40), which is disposed on said flow directing conduit (30), and said suction pump (40) is used for channelling water from said internal pot (10) to said steamer (20).

7. Cooking apparatus according to any of the Claims 3 to 5, wherein the internal diameter of said steamer suction tube (31) is at least 0.5mm and at most 20mm.

8. Cooking apparatus according to Claim 7, wherein the internal diameter of said steamer suction tube (31) is at least 1.5mm and at most 12mm.

9. Cooking apparatus according to any of the Claims 1 to 5, wherein the water drainage hole(s) (21) of said steamer (20) is disposed on the bottom wall and/or side wall of said steamer (20).

10.Cooking apparatus according to any of the Claims 1 to 5, wherein the center part of the bottom wall of said steamer (20) protrudes upwards, such that the bottom of said steamer (20) is higher at the center and lower at the edges.

11.Cooking apparatus according to any of the Claims 2 to 5, wherein one end of said flow directing conduit (30) that extends into said steamer (20) is equipped with nozzle (33).

12.Cooking apparatus according to Claim 6, wherein the end of said flow directing conduit (30) that extends into said steamer (20) is equipped with a nozzle (33).

13.Cooking apparatus according to any of the Claims 1 to 5, wherein there is a height difference of H1 between the lowest point on the bottom wall of said internal pot (10) and the lowest point on the bottom wall of said steamer (20), and said H1 is at least 0.1H and at most 0.8H, where H
is the height of said internal pot (10).

14.000king apparatus according to any of the Claims 1 to 5, wherein there is a height difference of H2 between the mouth of said internal pot (10) and the lowest point on the bottom wall of said steamer (20), and said H2 is at least 0.1H and at most 0.8H, where H is the height of said internal pot (10).