Production method and production device for cooked rice

Abstract

To provide a production method and a production device for cooked rice which can make delicious cooked rice even with a single-stage chamber.SOLUTION: A production method for cooked rice includes: a rice charging step of charging rice into a hopper; a rice supply step of supplying the rice from the hopper onto a transportation surface of transportation conveyer means disposed in a chamber; a water sprinkling step of sprinkling water over the rice on the transportation surface; a steaming step of injecting steam into the chamber to steam the rice on the transportation surface; and a stirring step of stirring a mass of the rice on the transportation surface by a stirrer disposed above the transportation surface. The stirrer is provided with a plate-shaped stirring blade whose longitudinal direction is a direction along a width direction of the transportation surface orthogonal to a transportation direction of the transportation conveyer means. The stirring blade is configured to be able to scoop a portion of the mass of the rice on the transportation surface where one of side edges thereof in the longitudinal direction is caused to go ahead into the mass of the rice from above the mass of the rice. A rotation direction of the one of side edges of the stirring blade when the stirring blade gets closer to the transportation surface of the transportation conveyer means is the same as a movement direction of the transportation surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for producing cooked rice. [Background technology]

[0002] An apparatus and method for continuously producing cooked rice are disclosed in, for example, Patent Document 1. As shown in FIG. 8, this apparatus includes a chamber 101 to which superheated or saturated steam is supplied, a conveyor 102 for transporting rice, and a sprinkler device 103 for sprinkling water on the rice transported in the chamber 101. The chamber 101 is vertically divided into a first chamber 101a, a second chamber 101b, and a third chamber 101c. The first chamber 101a and the second chamber 101b are provided in parallel to each other and communicate with each other via a partition wall 105 having a communication hole 104 formed therein. Similarly, the second chamber 101b and the third chamber 101c are provided in parallel to each other and communicate with each other via a partition wall 107 having a communication hole 106 formed therein. The conveyor 102 disposed within the chamber 101 is composed of a first conveyor 102a disposed in the first chamber 101a, a second conveyor 102b disposed in the second chamber 101b, and a third conveyor 102c disposed in the third chamber 101c.

[0003] To steam and cook cooked rice using such an apparatus, rice is placed on the first conveyor 102a in the first chamber 101a through a hopper 108. The rice fed onto the conveying surface of the first conveyor 102a is conveyed toward the right side of FIG. 8 while being cooked with superheated or saturated steam fed to the chamber 101 and water fed from the water sprinkler 103. The rice lump that reaches the right end of the first conveyor 101a is inverted and dropped onto the second conveyor 102b provided in the second chamber 101b through the communication hole 104, and is conveyed toward the left side of FIG. 8, and the rice lump that reaches the left end of the second conveyor 102b is inverted and dropped onto the third conveyor 102c through the communication hole 106, and is conveyed toward the right end of FIG. 8, and is discharged from the chamber 101 as cooked rice.

[0004] Thus, conventional cooked rice producing devices use a multi-stage chamber 101, and produce cooked rice by evenly cooking it by flipping the rice lumps as they fall from the upper chamber to the lower chamber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-169915 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, conventional rice manufacturing methods were carried out using equipment with chambers stacked in multiple tiers. However, in equipment with a single-tier chamber rather than stacked in multiple tiers, the rice mass could not be turned over, which led to uneven heating due to water supply from above and steam from below, making it difficult to cook tasty rice.

[0007] The present invention has been made to solve such problems, and has an object to provide a rice manufacturing method and apparatus that can cook delicious rice even when using a rice cooker with a single-stage chamber. [Means for solving the problem]

[0008] The object of the present invention is achieved by a method for producing cooked rice, comprising: a rice loading step of loading rice into a hopper; a rice supplying step of supplying rice from the hopper onto a conveying surface of a conveyor means disposed in a chamber; a watering step of spraying water on the rice on the conveying surface; a steaming step of injecting steam into the chamber to steam the rice on the conveying surface; and a stirring step of stirring the rice clumps on the conveying surface by an agitator disposed above the conveying surface, the agitator having a plate-shaped agitating blade whose longitudinal direction is along the width direction of the conveying surface perpendicular to the conveying direction of the conveyor means, the agitating blade being configured to be able to scoop up a part of the rice clump by inserting one side edge portion of the longitudinal direction of the agitating blade from above the rice clump on the conveying surface, and the rotation direction of the one side edge portion of the agitating blade when approaching the conveying surface of the conveyor means is the same as the movement direction of the conveying surface.

[0009] Furthermore, in the above-mentioned method for producing cooked rice, the speed ratio between the moving speed (m / s) of the conveying surface and the peripheral speed (m / s) of the one side edge of the stirring blade (moving speed of the conveying surface / peripheral speed of the one side edge of the stirring blade) is preferably in the range of 2 to 10. Moreover, it is more preferable to set the speed ratio to be in the range of 3 to 6.

[0010] Furthermore, with regard to the above-mentioned method for producing cooked rice, the stirring step is configured such that the stirring blade scoops up and stirs a portion of the rice clumps on the conveying surface each time the conveying surface moves a predetermined amount, and it is preferable that the predetermined amount is greater than or equal to 2 mm and less than or equal to 10 mm.

[0011] The agitator preferably includes a rotating shaft having an axial direction parallel to the width direction of the transport surface, and the agitating blade connected to the rotating shaft.

[0012] In addition, the plate-shaped stirring blade is preferably arranged at an inclination in the range of 15° to 90° with respect to a tangent line in the rotation direction at the one side edge of the stirring blade, more preferably at an inclination in the range of 20° to 75°, and even more preferably at an inclination in the range of 30° to 50°.

[0013] It is also preferable that the stirring blades are provided in a plurality of blades connected to the rotating shaft, and that the stirring blades are configured so as not to be positioned opposite each other across the rotating shaft.

[0014] It is also preferable that a plurality of the agitators are disposed at predetermined intervals along the conveying direction of the conveying surface.

[0015] The width of the plate-shaped stirring blade in the direction perpendicular to the one side edge is preferably in the range of 10 mm to 50 mm, more preferably in the range of 10 mm to 30 mm.

[0016] In addition, it is preferable that the stirring step further includes a step of stirring the rice clumps on the conveying surface by a second stirrer having a rotating shaft whose axial direction is along the width direction of the conveying surface and a plurality of rod-shaped bodies connected to the rotating shaft at predetermined intervals and extending radially outward from the rotating shaft.

[0017] It is also preferable that the method further comprises a water absorption step of supplying water to the inside of the hopper and allowing the rice inside the hopper to absorb the water.

[0018] In addition, the water supplied to the inside of the hopper in the water absorption step is preferably hot water having a temperature of 40°C or higher and 70°C or lower.

[0019] In addition, an opening is provided at the bottom of the hopper through which rice supplied onto the conveying surface of the transport conveyor means passes, and it is preferable that the opening is configured to be switchable between an open state and a closed state.

[0020] It is also preferable that a discharge passage for discharging the supplied water is formed in a lower portion of the hopper.

[0021] The object of the present invention is also achieved by a cooked rice manufacturing apparatus comprising: a conveying conveyor means disposed within a chamber; a rice supplying means for supplying rice onto the conveying surface of the conveying conveyor means; a sprinkling means for sprinkling water on the rice on the conveying surface; a steam injection device for injecting steam into the chamber for steaming the rice on the conveying surface; and an agitator disposed above the conveying surface for agitating the rice clumps on the conveying surface, the agitator having a plate-shaped agitating blade whose longitudinal direction is along the width direction of the conveying surface perpendicular to the conveying direction of the conveying conveyor means, the agitating blade being configured so that one side edge in the longitudinal direction can enter from above the rice clump on the conveying surface to scoop up a portion of the rice clump, and the rotation direction of the one side edge of the agitating blade when approaching the conveying surface of the conveying conveyor means is the same as the movement direction of the conveying surface.

[0022] Furthermore, in the cooked rice manufacturing apparatus, the speed ratio between the moving speed (m / s) of the conveying surface and the circumferential speed (m / s) of the one side edge of the stirring blade (moving speed of the conveying surface / circumferential speed of the one side edge of the stirring blade) is preferably in the range of 2 to 10. Moreover, it is more preferable to set the speed ratio to be in the range of 3 to 6.

[0023] In addition, it is preferable that the stirring blade is configured to scoop up and stir a portion of the rice clumps on the conveying surface each time the conveying surface moves a predetermined amount, and that the predetermined amount is set to be greater than or equal to 2 mm and less than or equal to 10 mm.

[0024] The agitator preferably includes a rotating shaft having an axial direction parallel to the width direction of the transport surface, and the agitating blade connected to the rotating shaft.

[0025] In addition, the plate-shaped stirring blade is preferably arranged so as to be inclined at an angle θ of 15° to 90° with respect to a tangent line in the rotation direction at the one side edge of the stirring blade, more preferably at an angle θ of 20° to 75°, and even more preferably at an angle θ of 30° to 50°.

[0026] It is also preferable that the stirring blades are provided in a plurality of blades connected to the rotating shaft, and that the stirring blades are configured so as not to be positioned opposite each other across the rotating shaft.

[0027] It is also preferable that a plurality of the agitators are disposed at predetermined intervals along the conveying direction of the conveying surface.

[0028] The width of the plate-shaped stirring blade in the direction perpendicular to the one side edge is preferably in the range of 10 mm to 50 mm, more preferably in the range of 10 mm to 30 mm.

[0029] It is also preferable that the device further comprises a second agitator having a rotating shaft whose axial direction is along the width direction of the conveying surface, and a plurality of rod-shaped bodies connected to the rotating shaft at predetermined intervals and extending radially outward from the rotating shaft.

[0030] It is also preferable that the rice supplying means further comprises a hopper into which rice is put, and water supplying means for supplying water into the inside of the hopper.

[0031] Moreover, it is preferable that the water supplied to the inside of the hopper by the water supply means is hot water having a temperature of 40°C or higher and 70°C or lower.

[0032] In addition, an opening is provided at the bottom of the hopper through which rice supplied onto the conveying surface of the transport conveyor means passes, and it is preferable that the opening is configured to be switchable between an open state and a closed state.

[0033] It is also preferable that a discharge passage for discharging the supplied water is formed in a lower portion of the hopper. Effect of the Invention

[0034] According to the present invention, it is possible to provide a rice manufacturing method and apparatus that can cook delicious rice even when a rice cooker has a single-stage chamber. [Brief description of the drawings]

[0035] [Figure 1] 1 is a schematic configuration diagram of a cooked rice manufacturing apparatus according to one embodiment of the present invention. FIG. [Diagram 2] 1 is a schematic diagram of a mixer provided in a cooked rice manufacturing apparatus according to the present invention, as viewed from a direction along the transport direction of a transport conveyor means. FIG. [Diagram 3] FIG. 3 is a schematic diagram of the cross section AA in FIG. 2. [Figure 4] FIG. 2 is an explanatory diagram of an agitating blade of an agitator provided in the cooked rice manufacturing apparatus according to the present invention. [Diagram 5] FIG. 10 is an explanatory diagram for explaining the effect of a mixer provided in the cooked rice manufacturing apparatus according to the present invention. [Figure 6] FIG. 2 is a schematic configuration diagram of a second mixer that may be provided in the cooked rice manufacturing apparatus according to the present invention, as viewed in a direction along the transport direction of the transport conveyor means. [Figure 7] FIG. 7 is a schematic diagram of the cross section BB in FIG. 6. [Figure 8] FIG. 1 is a schematic diagram of a conventional cooked rice manufacturing apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Hereinafter, a cooked rice manufacturing apparatus according to one embodiment of the present invention will be described with reference to the attached drawings. Note that the present invention is not limited to the following embodiment, and can be implemented by making appropriate modifications within the scope of the object of the present invention. Also, each drawing is partially enlarged or reduced in size to facilitate understanding of the configuration. As shown in the schematic configuration diagram of FIG. 1, the cooked rice manufacturing apparatus 1 according to the present invention includes a transport conveyor means 3 arranged in a single-stage chamber 2, a rice supplying means 4 for supplying rice onto the transport surface of the transport conveyor means 3, a water sprinkling means 5 for sprinkling water on the rice on the transport surface, and a steam injection device (not shown) for injecting steam into the chamber 2 to steam the rice on the transport surface.

[0037] The transport conveyor means 3 disposed within the chamber 2 is composed of an endless belt 31 and two wheels 32, 33 around which the belt 31 is wound. The belt 31 wound around the two wheels 32, 33 is formed in a net (mesh) shape. It is preferable to use a net (mesh) shape for the belt 31 in order to efficiently impart heat from steam to the rice as described below, but a belt other than a net (mesh) shape (for example, a resin belt) may also be used, and belts of various materials and shapes may be used.

[0038] The rice supplying means 4 is disposed above the chamber 2, and washed rice (raw rice) is continuously supplied onto the conveying surface of the conveyor means 3 through the rice supplying means 4. The rice supplied to the conveyor means 3 is not limited to washed rice, and may be unwashed rice. The concept of rice includes, for example, polished rice, brown rice, and mixed grain rice. The rice supplying means 4 is configured to include a hopper 41 into which rice is fed, and a water supplying means for supplying water to the inside of the hopper 41. An opening 42 through which rice supplied onto the conveying surface of the conveyor means 3 passes is provided at the bottom of the hopper 41, and a shutter is provided at the opening 42, which is configured to be switchable between an open state and a closed state. When the opening 42 is in an open state, rice in the hopper 41 is continuously supplied onto the conveying surface of the conveyor means 3, and when the opening 42 is in a closed state, the supply of rice from the hopper 41 onto the conveying surface of the conveyor means 3 is stopped. In addition, a discharge flow path is formed in the lower part of the hopper 41, through which the water supplied from the water supply means is discharged. The configuration of the discharge flow path is not particularly limited, but for example, the bottom of the hopper 41 has a double structure having an upper bottom plate and a lower bottom plate that forms a space between the upper bottom plate, and a small through hole is provided in the upper bottom plate (the bottom plate that comes into contact with the rice) on the inside side of the hopper 41, so that the water can flow out into the space through the through hole, and the water led to the space can be discharged to the outside through a discharge pipe. Note that the discharged water may be filtered, etc., and then returned to the water supply means to be supplied again into the hopper 41.

[0039] The water sprinkling means 5 is composed of piping 51 that supplies cold water, hot water, or room temperature water, for example, at about 15°C to about 90°C, from a tank (not shown), and spray nozzles 52. A plurality of spray nozzles 52 are provided at predetermined positions of the piping 51, and can sprinkle hot water supplied from the hot water tank, for example, in a mist or fan shape.

[0040] As described above, the steam injection device is a device that injects steam into chamber 2 for steaming rice on the transport surface of transport conveyor means 3, and is composed of a steam generation device such as a boiler and piping. The steam generated in the steam generation device may be water vapor at 100°C or less, or superheated water vapor at 100°C or more. Note that superheated water vapor means water vapor that is superheated to above its boiling point (100°C at 1 atmosphere, and the boiling point at an atmosphere other than 1 atmosphere). Superheated water vapor can be formed by reheating saturated water vapor with a heating device such as a heater, but any method for forming the superheated water vapor may be used.

[0041] A portion of the piping connected to the steam generating device is extended to the inner area 31a of the mesh belt 31 provided in the transport conveyor means 3, and a through hole is formed in the extended portion of the piping. The steam generated by the steam generating device passes through the piping, is discharged from the through hole, and is supplied to the space area above the belt 31 through the mesh portions of the belt 31 formed in a mesh shape.

[0042] In addition to the above configuration, the cooked rice manufacturing apparatus 1 according to the present invention is equipped with an agitator 6 for agitating the rice lumps on the conveying surface of the conveyor means 3. As shown in FIG. 1, the agitator 6 is disposed above the conveying surface of the conveyor means 3, and as shown in the schematic configuration diagrams of FIG. 2 and FIG. 3, the agitator 6 is equipped with a plate-shaped agitating blade 61 whose longitudinal direction is along the width direction of the conveying surface perpendicular to the conveying direction of the conveyor means 3. Here, FIG. 2 is a schematic configuration diagram seen from the direction along the conveying direction of the conveyor means 3, and FIG. 3 is a schematic configuration diagram of the AA cross section of FIG. 2. The agitating blade 61 is configured to be connected to a rotating shaft 62 whose axial direction is along the width direction of the conveying surface of the conveyor means 3, and the agitating blade 61 is installed via a plurality of plate-shaped connecting members 63 so that its longitudinal direction is parallel to the longitudinal direction of the rotating shaft 62. A through hole is formed in the center of each connecting member 63, and the rotating shaft 62 is inserted through the through hole and fixed on the rotating shaft 62. The connecting member 63 has three arm parts 64 protruding in the radial direction of the rotating shaft 62, and the stirring blade 61 is connected and fixed to the tip of each arm part 64. Each arm part 64 is configured to be arranged at an equal angular position around the rotating shaft 62, and each stirring blade 61 connected and fixed to the tip of each arm part 64 is also configured to be arranged at an equal angular position around the rotating shaft 62. In addition, it is preferable that the length of the stirring blade 61 in the longitudinal direction is configured to be approximately equal to the length of the conveying surface of the transport conveyor means 3 in the width direction. A driving device such as an electric motor (not shown) is connected to the rotating shaft 62, and the driving device is configured to rotate the rotating shaft 62 at a predetermined speed. In addition, the rotation speed of the stirrer 6 is configured to be controlled by a control device. According to the stirrer 6 configured in this way, the stirring blade 61 can enter one side edge part 61a in the longitudinal direction from above the rice clump on the conveying surface of the transport conveyor means 3, and scoop up and stir a part of the rice clump. The number of stirring blades 61 is not particularly limited, but is preferably about 2 to 8. Furthermore, a plurality of the stirrers 6 may be disposed at predetermined intervals along the conveying direction of the conveying surface, or a single stirrer 6 may be disposed.Here, the agitator 6 is preferably installed at a position that equally divides the distance between the position (entrance) where rice is fed onto the transport conveyor means 3 by the rice supplying means 4 and the position (outlet) where rice is discharged from the transport surface of the transport conveyor means 3. For example, when multiple agitators 6 are provided as shown in Fig. 1, it is preferable to arrange the agitators 6 so that the distance between the entrance and the foremost agitator 6, the distance between each agitator 6, and the distance between the rearmost agitator 6 and the outlet are uniform.

[0043] The agitator 6 can be rotated in any direction. However, when the agitator 6 is rotated in the opposite direction to the moving direction of the belt 31 of the conveyor means 3, the rice lumps moving on the belt 31 can be efficiently scooped up. However, depending on the rotation speed, the smooth movement of the rice lumps may be hindered. Therefore, it is preferable that the agitator 6 rotates in the same direction as the moving direction of the belt 31, that is, the rotation direction of one side edge 61a of the agitator blade 61 when approaching the belt 31 of the conveyor means 3 is the same as the moving direction of the belt 31. Furthermore, from the viewpoint of increasing the efficiency of agitation and mixing, it is preferable to configure the side edge 61a of each agitator blade 61 so that the distance between the belt 31 and the belt 31 when it is closest to the belt 31 is within a range of about 2 mm or less. Generally, individual rice grains to be steamed and cooked have adhesive properties with other rice grains, so by setting the distance between the side edge of the agitator blade 61 and the belt 31 when it is closest to the belt 31 to about 2 mm or less, it is possible to mix almost all the rice uniformly. If this distance is set to a dimension exceeding 2 mm, there is a risk that all of the rice will not be mixed uniformly due to the adhesiveness of individual rice grains.

[0044] In addition, as shown in FIG. 3, the stirring blade 61 is preferably inclined so that the rice clumps moving on the belt 31 can be efficiently scooped up. The angle of inclination can be appropriately designed by comprehensively considering the amount of rice clumps moving on the belt 31 and the adhesiveness of the rice. For example, as shown in FIG. 4, the stirring blade 61 is preferably inclined at an angle θ of 15° to 90° with respect to the tangent line of the rotation direction at one side edge of the plate-like stirring blade 61, more preferably at an angle θ of 20° to 75°, and even more preferably at an angle θ of 30° to 50°. By arranging the stirring blade 61 at such an angle range, it is possible to efficiently scoop up the rice clump while suppressing crushing of the rice in the rice clump and invert the rice clump. In addition, the width dimension W in the direction perpendicular to one side edge of the plate-like stirring blade 61 is preferably in the range of 10 mm to 50 mm, and more preferably in the range of 10 mm to 30 mm. In this range of values, it is possible to efficiently scoop up the rice lump and turn it over.

[0045] Here, in the agitator 6 according to the present invention, the agitating blade 61 enters the rice clump on the conveying surface of the conveyor means 3 from above with one side edge 61a in the longitudinal direction, and scoops up a part of the rice clump. The speed ratio between the moving speed of the conveying surface (m / s) and the circumferential speed of one side edge of the agitating blade (m / s) is preferably set to a range of 2 to 10, more preferably set to a range of 3 to 6. By setting such a speed ratio, it becomes possible to efficiently scoop up the rice clumps and turn over all the rice clumps on the conveyor means 3. In addition, it is preferable that the scooping up of the rice clumps on the conveying surface is configured such that one agitating blade 61 scoops up and agitates a part of the rice clumps on the conveying surface every time the conveying surface of the conveyor means 3 moves a predetermined amount, more specifically, every time the conveying surface moves in a range of 2 mm to 10 mm. The rotation speed of the agitator 6 is configured to be controlled by the control device as described above, but the specific configuration of the control device is not particularly limited as long as it has a function of arbitrarily changing and setting the rotation speed of the agitator 6. In addition, the peripheral speed of one side edge of the agitator blade may be automatically calculated based on the moving speed of the transport surface of the transport conveyor means 3 so that the speed ratio falls within the above-mentioned range, or so that the agitator blade 61 can scoop up and agitate part of the rice clumps on the transport surface every time the transport surface moves within a range of 2 mm to 10 mm, and the agitator 6 may be rotated based on the calculated speed.

[0046] A method for steaming and cooking cooked rice using the cooked rice manufacturing apparatus 1 having such a configuration will be described below. First, the opening 42 provided at the bottom of the hopper 41 of the rice supplying means 4 is closed, and rice is put into the hopper 41 (rice putting step). The rice put into the hopper 41 is stored in the hopper 41 because the opening 42 at the bottom of the hopper 41 is closed. Next, water is supplied to the rice stored in the hopper 41 via the water supplying means, and the rice inside the hopper 41 absorbs the water (water absorbing step). After the rice absorbs water and the moisture content of the rice becomes, for example, 25% or more, the shutter at the opening 42 at the bottom of the hopper 41 is opened to open the rice, and the rice after absorbing the water is sequentially supplied onto the conveying surface of the conveying conveyor means 3. Here, for example, when hot water of 40°C to 70°C is used as the water supplied into the hopper 41 via the water supplying means, the moisture content of the rice becomes about 25% in about 5 minutes. Although the moisture content of the rice does not reach 25%, water at room temperature of 20°C to 30°C or cold water may be used. The water supplied to the inside of the hopper 41 is discharged to the outside through a discharge flow path provided at the bottom of the hopper 41.

[0047] Here, after the opening 42 at the bottom of the hopper 41 is opened, rice is continuously put into the hopper 41 and water is continuously supplied from the water supply means. The newly put rice into the hopper 41 moves downward in the hopper 41 as the rice present below the hopper 41 and absorbing water is supplied to the transport conveyor means 3 through the opening 42. During the downward movement, the rice comes into contact with water supplied from above through the water supply means and absorbs water, and when the rice is transferred from the opening 42 onto the transport conveyor means 3, sufficient water absorption is completed. For example, when hot water of 40°C to 70°C is used as the water supplied into the hopper 41 through the water supply means, the moisture content of the rice becomes about 25% in about 5 minutes as described above, so that the internal volume of the hopper 41 is preferably configured to be large enough to allow the rice put into the hopper 41 to reach the opening 42 at the bottom in about 5 minutes. Furthermore, the temperature of the water supplied into the hopper 41 via the water supply means is not limited to the above-mentioned warm water of about 40°C to 70°C, and water at a temperature of 40°C or less can also be used. In this case, since it takes more than 5 minutes for the moisture content of the rice to reach about 25%, the size of the hopper 41 is appropriately changed and configured to be a size such that the moisture content of the rice put into the hopper 41 will be about 25% when it reaches the opening 42 at the bottom. Furthermore, the moisture content of the rice when it is supplied from the opening 42 at the bottom of the hopper 41 onto the conveying surface of the transport conveyor means 3 is not limited to about 25% as described above, and may be configured to be about 18% to 30%.

[0048] In the chamber 2, hot water of, for example, about 60°C to about 95°C is sprayed onto the rice via the spraying means (spraying step), and steam generated by the steam generating device is supplied to the space above the mesh belt 31 via piping extending to the inner area 31a of the belt 31, so that the rice lumps on the transport conveyor means 3 are steamed and cooked by the steam passing through the mesh belt 31 and the steam supplied into the chamber 2 (steaming step). The water sprayed in the spraying step may be cold water.

[0049] The rice lumps transported on the transport conveyor means 3 are steamed while being uniformly loosened by the action of each agitator 6 (agitation step). As described above, the agitator 6 has one longitudinal edge 61a of the agitator blade 61 enter from above the rice lumps on the transport surface of the transport conveyor means 3 to scoop up part of the rice lumps, and this scooping up of the rice lumps on the transport surface is performed under a speed ratio (movement speed of the transport surface / peripheral speed of one side edge of the agitator blade) of the moving speed of the transport surface (m / s) to the circumferential speed of one side edge of the agitator blade in the range of 2 to 10. More preferably, the agitator 6 is configured so that part of the rice lumps on the transport surface is scooped up and agitated every time the transport surface of the transport conveyor means 3 moves in the range of 2 to 10 mm.

[0050] The rice chunks that have been supplied to the transport conveyor means 3 in this manner, stirred by the stirrer 6 while being transported, and after the steaming and cooking are completed, are removed from the end of the transport conveyor means 3 in the transport direction (the right end part in FIG. 1).

[0051] The above-mentioned manufacturing method and manufacturing device for cooked rice includes an agitator 6 arranged above the conveying surface of the conveyor means 3, and the agitator 6 includes a plate-shaped agitating blade 61 with a longitudinal direction along the width direction of the conveying surface perpendicular to the conveying direction of the conveyor means 3, and the agitating blade 61 is configured to be able to scoop up a part of the rice clump by inserting one side edge 61a in the longitudinal direction from above the rice clump on the conveying surface. Furthermore, the speed ratio (moving speed of the conveying surface / circumferential speed of one side edge of the agitating blade) between the moving speed (m / s) of the conveying surface and the circumferential speed of one side edge of the agitating blade is configured to be in the range of 2 to 10, so that the rice clump can be uniformly heated by water supplied from above and steam supplied from below during the steaming process, and delicious cooked rice can be manufactured even with a single-stage chamber.

[0052] In addition, the stirring blade 61 is configured to scoop up and stir a part of the rice lump on the conveying surface every time the conveying surface of the conveyor means 3 moves in the range of 2 mm to 10 mm, which makes it possible to further uniformize the heating by water supply and steam during the steaming process, and to produce delicious cooked rice. Specifically, since the size of a typical grain of rice is about 2 to 3 mm in width and about 5 to 6 mm in length, this configuration makes it possible to scoop up and stir the rice lump in a manner that peels off a thin layer of the rice lump, which is about the thickness of 1 to 3 grains of rice. As a result, during the steaming process, it becomes possible to turn over the rice lump while exposing at least a part of the surface of each grain of rice in the rice lump conveyed on the conveyor means 3, and also to prevent the cooked rice from sticking to each other and becoming lumpy, thereby producing more uniformly delicious cooked rice.

[0053] Furthermore, in the above-mentioned cooked rice manufacturing method and manufacturing device, the rice supplying means that supplies rice onto the conveying surface of the transport conveyor means includes a hopper 41 into which the rice is put, and a water supplying means that supplies water to the inside of the hopper 41, and is configured to allow the rice to absorb water during the time it takes to be transferred from the inside of the hopper 41 to the transport conveyor means, so there is no need for a separate process of allowing the rice to absorb water in a soaking tank, and cooked rice can be manufactured more efficiently and in a shorter time. Also, there is no need to provide a separate soaking tank, and the manufacturing device can be made more compact.

[0054] In addition, when hot water of about 40°C to 70°C is used as the water supplied to the inside of the hopper 41 through the water supply means, the moisture content of the rice becomes about 25% in a short time of about 5 minutes, so that even if unsoaked rice is supplied to the hopper 41, extremely delicious cooked rice can be produced. On the other hand, when rice is cooked using the conventional kettle method, the inner cell components are likely to leak from the cell walls of the rice due to physical collisions caused by boiling, etc., but according to the method of the present invention, the leakage of the inner cell components from the cell walls of the rice can be prevented and cooked rice can be produced. As a result, the rice cooking increase rate (cooking rate) can be increased to 2.4 to 2.6 times, and the deliciousness of the rice can be fully and firmly locked in the cooked rice. Here, the rice cooking increase rate (cooking rate) means the ratio of the weight of cooked rice to the weight of raw rice. In other words, it indicates the weight ratio of cooked rice when the weight of raw rice before cooking is set to 1.

[0055] Although the cooked rice manufacturing method and manufacturing device according to one embodiment of the present invention have been described above, the specific configuration is not limited to the above embodiment. For example, the cooked rice manufacturing device 1 in the above embodiment is configured to have a single single-stage chamber 2, but the cooked rice manufacturing device 1 may be configured by stacking this single-stage chamber 2 in multiple stages (for example, two or three stages). When such a configuration is adopted, the amount of cooked rice manufactured can be increased in proportion to the number of stacked chambers 2.

[0056] In the above embodiment, the stirring blades 61 are arranged at equal angular positions around the rotation shaft 62, but are not particularly limited to this configuration. It is preferable that the stirring blades 61 are arranged so that they are not arranged at opposing positions across the rotation shaft 62. When the stirring blades 61 are arranged at equal angular positions around the rotation shaft 62, it is preferable to have an odd number of stirring blades, such as three or five. When a larger amount of rice is transported onto the transport surface of the conveyor 3 in order to increase the production volume of cooked rice, the height of the transported rice clumps may become higher than the height of the rotating shaft 62, for example, as shown in Figure 5. In such a case, if a configuration is adopted in which a pair of agitating blades 61 are arranged in opposing positions across the rotating shaft 62, the rice clumps (the rice clumps in the area surrounded by the dashed line in the figure) will be wrapped up between the pair of agitating blades 61, and the wrapped up rice clumps will not be able to escape from around the rotating shaft 62 and will remain around the rotating shaft 62, causing the rice clumps to become sticky and clog. However, by configuring each agitating blade 61 so that the agitating blades 61 are not arranged in opposing positions across the rotating shaft 62, it is possible to prevent the rice clumps from being wrapped up and effectively prevent the rice clumps from clogging around the rotating shaft 62.

[0057] In addition, the cooked rice manufacturing apparatus 1 may be configured to use a second agitator 7 as shown in the schematic configuration diagrams of FIG. 6 and FIG. 7. Here, FIG. 6 is a schematic configuration diagram seen from the direction along the conveying direction of the conveyor means 3, and FIG. 7 is a schematic configuration diagram of the BB cross section of FIG. 6. This second agitator 7 is configured to include a rotating shaft 71 whose axial direction is along the width direction of the conveying surface of the conveyor means 3, and a plurality of rod-shaped bodies 72 attached to this rotating shaft 71 at a predetermined interval. Each rod-shaped body 72 is, for example, inserted and fixed in an insertion hole formed on the rotating shaft 71, and is configured to extend toward the radial outside of the rotating shaft (the longitudinal direction of the rod-shaped body 72 is in the radial direction of the rotating shaft 71). In addition, the rod-shaped bodies 72 adjacent to each other are arranged at positions shifted by a predetermined angle on the rotating shaft 71. In addition, it is preferable that a plurality of second agitators 7 are arranged at predetermined intervals along the conveying direction of the conveying surface. In particular, it is preferable to configure the second agitator 7 to be disposed between the agitators 6. A drive device such as an electric motor (not shown) is connected to the rotating shaft 71 of the second agitator 7, and the second agitator 7 is configured to be rotatable at a predetermined speed by the drive device. The rotation speed of the second agitator 7 is configured to be controlled by a control device. The second agitator 7 can be rotated in any direction, but when the second agitator 7 is rotated in the opposite direction to the traveling direction of the belt 31 of the conveyor means 3, it is possible to efficiently agitate the rice clumps traveling on the belt 31. However, depending on the rotation speed, it may hinder the smooth progression of the rice clumps, so it is preferable to rotate the second agitator 7 in the same direction as the traveling direction of the belt 31. Furthermore, it is preferable to configure the distance between the tip of each rod-shaped body 72 and the belt 31 when it is closest to the belt 31 to be within a range of about 2 mm or less from the viewpoint of increasing the stirring and mixing efficiency. By using the second agitator 7 with such a configuration, it is possible to form streaks in the rice lumps along the transport direction of the transport conveyor 3 while loosening the rice lumps transported on the transport conveyor means 3, and hot water supplied from above by the water sprinkler device can easily permeate evenly along the formed streaks to the lower side of the rice lumps. In addition, the formation of the streaks makes it easier for steam supplied from below to escape to the upper part of the rice lumps.In other words, it is possible to eliminate a state in which the upper part of the rice lump on the conveying surface receives an excessive amount of water from the sprinkler device, and a state in which the lower part of the rice lump is overheated by steam, and a better balance can be achieved between the water supply to the rice lump from above and the heating by the steam supplied from below, making it possible to produce even more delicious cooked rice. Even when such a second agitator 7 is used in combination, it is preferable to install the agitator 6 and the second agitator 7 at positions that equally divide the distance between the position (entrance) where the rice is fed onto the conveyor means 3 by the rice supplying means 4 and the position (exit) where the rice is discharged from the conveying surface of the conveyor means 3, as described above. [Explanation of symbols]

[0058] 1. Rice production equipment 2. Chamber 2 3. Conveyor means 31 Belt 32,33 Wheels 4 Rice supply means 41 Hopper 42 Opening 5. Watering means 51 Piping 52 Spray nozzle 6 Mixer 61 Stirring blade 61a Side edge 62 Rotational Axis 63 Connection parts 64 Arm section 7 Second Mixer 71 Rotational Axis 72 Rod-shaped body

Claims

1. a rice charging step of charging rice into the hopper; a rice supplying step of supplying rice from the hopper onto a conveying surface of a conveyor means disposed within a chamber; A water spraying step of spraying water on the rice on the conveying surface; a steaming step of injecting steam into a chamber to steam the rice on the conveying surface; and a stirring step of stirring the rice lumps on the conveying surface by a stirrer disposed above the conveying surface; The agitator is provided with a plate-shaped agitating blade having a longitudinal direction along the width direction of the conveying surface perpendicular to the conveying direction of the conveyor means, and the agitating blade is configured to be able to scoop up a part of the rice lump by inserting one side edge portion in the longitudinal direction of the agitating blade from above the rice lump on the conveying surface, A method for producing cooked rice, characterized in that the rotation direction of the one side edge of the stirring blade when approaching the conveying surface of the transport conveyor means is the same as the movement direction of the conveying surface.

2. The method for producing cooked rice according to claim 1, characterized in that the speed ratio (movement speed of the conveying surface / circumferential speed of the one side edge of the stirring blade) between the moving speed (m / s) of the conveying surface and the peripheral speed (m / s) of the one side edge of the stirring blade is in the range of 2 or more and 10 or less.

3. The stirring step is configured such that the stirring blade scoops up and stirs a portion of the rice lump on the conveying surface every time the conveying surface moves a predetermined amount, The method for producing cooked rice according to claim 1 or 2, characterized in that the predetermined amount is 2 mm or more and 10 mm or less.

4. The method for producing cooked rice according to claim 1 or 2, characterized in that the agitator is provided with a rotating shaft whose axial direction is along the width direction of the conveying surface, and the agitating blade connected to the rotating shaft.

5. The method for producing cooked rice according to claim 4, characterized in that the plate-shaped agitating blade is arranged at an inclination in the range of 15° to 90° with respect to a tangent to a rotational direction at the one side edge of the agitating blade.

6. The method for producing cooked rice according to claim 3, characterized in that a plurality of the stirring blades are provided which are connected to the rotating shaft, and each stirring blade is configured so as not to be positioned in an opposing position across the rotating shaft.

7. 3. The method for producing cooked rice according to claim 1, wherein a plurality of the agitators are arranged at predetermined intervals along the conveying direction of the conveying surface.

8. 3. The method for producing cooked rice according to claim 1 or 2, wherein a width dimension of the plate-shaped stirring blade in a direction perpendicular to the one side edge portion is in a range of 10 mm to 50 mm.

9. The method for producing cooked rice according to claim 1 or 2, characterized in that the stirring step further comprises a process of stirring the rice lumps on the conveying surface by a second stirrer having a rotating shaft whose axial direction is along the width direction of the conveying surface and a plurality of rod-shaped bodies connected to the rotating shaft at predetermined intervals and extending radially outward from the rotating shaft.

10. The method for producing cooked rice according to claim 1 or 2, further comprising a water absorption step of supplying water to the inside of the hopper and allowing the rice inside the hopper to absorb the water.

11. The method for producing cooked rice according to claim 10, wherein the water supplied to the inside of the hopper in the water absorption step is hot water having a temperature of 40°C or higher and 70°C or lower.

12. The method for producing cooked rice according to claim 10, wherein an opening is provided at the bottom of the hopper through which rice supplied onto the conveying surface of the transport conveyor means passes, and the opening is configured to be switchable between an open state and a closed state.

13. The method for producing cooked rice according to claim 10, wherein a discharge flow path through which the supplied water is discharged is formed in a lower portion of the hopper.

14. a transport conveyor means disposed within the chamber; a rice supplying means for supplying rice onto a conveying surface of the conveyor means; A water sprinkling means for sprinkling water on the rice on the conveying surface; a steam injection device that injects steam into the chamber to steam the rice on the conveying surface; and an agitator disposed above the conveying surface for agitating the rice lumps on the conveying surface. The agitator is provided with a plate-shaped agitating blade having a longitudinal direction along the width direction of the conveying surface perpendicular to the conveying direction of the conveyor means, and the agitating blade is configured to be able to scoop up a part of the rice lump by inserting one side edge portion in the longitudinal direction of the agitating blade from above the rice lump on the conveying surface, A cooked rice manufacturing apparatus, characterized in that the rotation direction of the one side edge portion of the stirring blade when approaching the transport surface of the transport conveyor means is the same as the movement direction of the transport surface.

15. The cooked rice manufacturing apparatus according to claim 14, characterized in that the speed ratio (movement speed of the conveying surface / circumferential speed of the one side edge of the stirring blade) between the moving speed (m / s) of the conveying surface and the peripheral speed (m / s) of the one side edge of the stirring blade is in the range of 2 or more and 10 or less.

16. The stirring blade is configured to scoop up and stir a portion of the rice lump on the conveying surface every time the conveying surface moves a predetermined amount, The cooked rice manufacturing device according to claim 14 or 15, characterized in that the predetermined amount is set to be equal to or greater than 2 mm and equal to or less than 10 mm.

17. The cooked rice manufacturing apparatus according to claim 14 or 15, characterized in that the agitator comprises a rotating shaft whose axial direction is along the width direction of the conveying surface, and the agitating blade connected to the rotating shaft.

18. The method for producing cooked rice according to claim 17, characterized in that the plate-shaped agitating blade is arranged at an angle of 15° to 90° with respect to a tangent to a rotational direction at the one side edge of the agitating blade.

19. The method for producing cooked rice according to claim 17, characterized in that a plurality of the stirring blades are provided which are connected to the rotating shaft, and the stirring blades are configured so as not to be positioned in opposing positions across the rotating shaft.

20. The cooked rice manufacturing apparatus according to claim 14 or 15, wherein a plurality of the agitators are arranged at predetermined intervals along the conveying direction of the conveying surface.

21. 16. The method for producing cooked rice according to claim 14 or 15, wherein the width dimension of the plate-shaped stirring blade in a direction perpendicular to the one side edge portion is in the range of 10 mm to 50 mm.

22. The cooked rice manufacturing apparatus according to claim 14 or 15, further comprising a second agitator having a rotating shaft whose axial direction is along the width direction of the conveying surface, and a plurality of rod-shaped bodies connected to the rotating shaft at a predetermined interval and extending radially outward from the rotating shaft.

23. 16. The cooked rice manufacturing apparatus according to claim 14, wherein the rice supplying means further comprises a hopper into which rice is poured, and a water supplying means for supplying water into the inside of the hopper.

24. The cooked rice manufacturing apparatus according to claim 23, characterized in that the water supplied to the inside of the hopper by the water supply means is hot water having a temperature of 40°C or higher and 70°C or lower.

25. The cooked rice manufacturing apparatus according to claim 23, wherein an opening is provided at the bottom of the hopper through which rice supplied onto the conveying surface of the transport conveyor means passes, and the opening is configured to be switchable between an open state and a closed state.

26. The cooked rice manufacturing apparatus according to claim 23, wherein a discharge flow path through which the supplied water is discharged is formed in a lower portion of the hopper.

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