Conveyor

Abstract

To produce delicious rice by steam rice cooking.SOLUTION: A pair of drums 46 that rotate on the upstream side and the downstream side in the conveying direction, an endless net 42 that is wound around the pair of drums, sprockets 46c and 46b that are coaxial with the drum of the pair of drums that is rotated by a drive motor 46a and that rotate in synchronization with the drum, and endless chains 43 and 44 that are connected to the net on both sides in a direction perpendicular to the conveying direction and that are formed of a plurality of links driven by the rotating sprockets, A drum rotating coaxially and synchronously with a sprocket is a polygonal drum formed in a polygonal shape in which a cross-sectional shape orthogonal to an axial direction has a length of one side corresponding to a length of a pitch of a link constituting a chain, and an endless net positioned on the polygonal drum is driven in contact along the polygon.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a conveyor used in steam rice cookers for cooking large amounts of rice, such as those used in school lunches and employee cafeterias. [Background technology]

[0002] One example of this type of steam rice cooker is described in Patent Document 1, which is a steam rice cooker used in fields where large quantities of rice are cooked, such as in the lunch delivery business, food service companies, and the restaurant industry. The primary soaking involves soaking polished rice in water stored in the primary soaking section for a predetermined time, and after the primary soaking, the polished rice is transported on a conveyor while steam is supplied for primary steaming. After this primary steaming is complete, the polished rice is placed in water at 85 to 90 degrees C stored in a heated water tank in the secondary soaking section, where it is transported while undergoing secondary soaking, and is then continuously transported on the conveyor, where steam is again supplied for secondary steaming, thereby steam cooking the rice. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-181840 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the method described in Patent Document 1, the rice is continuously transported onto a conveyor where the secondary steaming is carried out while a large amount of water from the heated water tank for the secondary soaking remains attached to the rice. As a result, the rice is gelatinized and a film is formed on the surface of the rice when the secondary steaming is carried out, and the steam supplied during the secondary steaming does not reach the inside of the rice, making it difficult to gelatinize the inside of the rice to the extent that tasty rice, for example, rice with a high moisture content that does not dry out easily, can be produced.

[0005] An object of the present invention is to provide a steam rice cooker and a method for producing cooked rice that can produce delicious rice by steam cooking. [Means for solving the problem]

[0006] In order to achieve the above object, the steam rice cooker of the present invention comprises: a primary soaking unit having a primary soaking tank that stores soaking water for soaking the polished rice; a primary steaming section that has a primary steaming conveyor that stacks the polished rice soaked in the soaking water in the primary soaking section on a conveying surface and conveys the polished rice downstream in the conveying direction, and supplies steam to the polished rice stacked on the conveying surface of the primary steaming conveyor; a secondary soaking section that soaks the white rice conveyed from the primary steaming section in soaking water stored in a secondary soaking tank while conveying the white rice downstream in the conveying direction; The apparatus has a secondary steaming conveyor that stacks the polished rice that has been soaked in the soaking water in the secondary soaking section on a conveying surface and conveys it downstream in the conveying direction, and a secondary steaming section that supplies steam to the polished rice stacked on the conveying surface of the secondary steaming conveyor to complete the gelatinization of the polished rice that has been secondarily soaked, The secondary steaming section a first superheated steam supply unit that supplies superheated steam to the polished rice that is stacked and conveyed on the conveying surface of the secondary steaming conveyor; A second steam supply unit that supplies steam to the polished rice that is stacked and transported on the transport surface of the secondary steaming conveyor, downstream of the first superheated steam supply unit in the transport direction; have It is characterized by the following.

[0007] Further, the method for producing cooked rice of the present invention is a first soaking step in which polished rice is soaked in soaking water for a predetermined time; a primary steaming step in which the polished rice that has been subjected to the primary soaking step is stacked on a conveying surface of a conveyor and brought into contact with steam while being conveyed; a second soaking step in which the polished rice that has been subjected to the first steaming step is placed in soaking water at a predetermined temperature and soaked for a predetermined time while being transported by a conveyor; a secondary steaming step in which the polished rice that has been subjected to the secondary soaking step is stacked on the conveying surface of a conveyor and conveyed while being exposed to steam to complete gelatinization of the polished rice; Including, The second steaming step is a first superheated steam supply step in which superheated steam is brought into contact with the polished rice that has been subjected to the second soaking step to heat the polished rice while evaporating moisture adhering to the polished rice; and a steam supplying step of contacting steam with the polished rice that has been subjected to the first superheated steam supplying step to gelatinize the polished rice. It is characterized by the following. [Effects of the Invention]

[0008] As described above, the steam rice cooker and the method for producing cooked rice of the present invention make it possible to produce delicious rice by steam cooking. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing the overall configuration of a steam rice cooker according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the configuration of a front-end process section of the steam rice cooker. [Figure 3] FIG. 2 is a block diagram showing the configuration of the primary immersion unit of the steam rice cooker. [Figure 4] FIG. 2 is an enlarged perspective view showing the configuration of a ridge forming plate and its surroundings of the steam rice cooker. [Figure 5] FIG. 2 is a perspective view showing the polygonal drum and its surrounding structure of the steam rice cooker. [Figure 6] FIG. 4 is an enlarged perspective view showing the configuration of a plurality of vent holes in the first steam concentrating plate and openings in the second steam concentrating plate of the steam rice cooker. [Figure 7] FIG. 3 is an enlarged perspective view showing the configuration of a first steam supply unit of the steam rice cooker. [Figure 8] FIG. 3 is an enlarged plan view showing a connection portion between the chain and the net of the steam rice cooker. [Figure 9] FIG. 3 is an enlarged perspective view showing a first superheated steam supply unit, a second steam supply unit, and a second superheated steam supply unit of the secondary steaming unit of the steam rice cooker. [Figure 10] FIG. 2 is a block diagram showing the outlet section of the steam rice cooker. [Figure 11]FIG. 1 is a step diagram showing a method for producing cooked rice. [Figure 12] 1 is a cross-sectional view showing an overview of steam passing through multiple vent holes in the first steam concentrating plate and openings in the second steam concentrating plate from the start of the primary steaming step until a predetermined time. FIG. [Figure 13] 10 is a cross-sectional view showing an overview of steam passing through multiple vent holes in the first steam concentrating plate and openings in the second steam concentrating plate after a predetermined time has elapsed since the start of the primary steaming step. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The first invention is a primary soaking unit having a primary soaking tank that stores soaking water for soaking the polished rice; a primary steaming section that has a primary steaming conveyor that stacks the polished rice soaked in the soaking water in the primary soaking section on a conveying surface and conveys the polished rice downstream in the conveying direction, and supplies steam to the polished rice stacked on the conveying surface of the primary steaming conveyor; a secondary soaking section that soaks the white rice conveyed from the primary steaming section in soaking water stored in a secondary soaking tank while conveying the white rice downstream in the conveying direction; The apparatus has a secondary steaming conveyor that stacks the polished rice that has been soaked in the soaking water in the secondary soaking section on a conveying surface and conveys it downstream in the conveying direction, and a secondary steaming section that supplies steam to the polished rice stacked on the conveying surface of the secondary steaming conveyor to complete the gelatinization of the polished rice that has been secondarily soaked, The secondary steaming section a first superheated steam supply unit that supplies superheated steam to the polished rice that is stacked and conveyed on the conveying surface of the secondary steaming conveyor; A second steam supply unit that supplies steam to the polished rice that is stacked and transported on the transport surface of the secondary steaming conveyor, downstream of the first superheated steam supply unit in the transport direction; have This is a steam rice cooking device characterized by the above.

[0011] As a result, superheated steam is brought into contact with the white rice in the first superheated steam supply section of the secondary steaming section, evaporating the moisture adhering to the surface of the white rice while heating the white rice and evaporating the moisture inside the white rice, forming multiple cavities on the surface of the white rice.

[0012] Then, by supplying steam to the polished rice using the second steam supply unit, steam is supplied into the cavities formed on the surface of the polished rice, promoting gelatinization of the polished rice. Furthermore, by supplying steam into the cavities formed on the surface of the polished rice, the steam reaches the inside of the polished rice, producing truly delicious rice that is gelatinized all the way to the core.

[0013] The second invention is the first invention, The secondary steaming section is The conveyor further includes a second superheated steam supply unit that supplies superheated steam to the polished rice that is stacked and conveyed on the conveyance surface of the secondary steaming conveyor downstream of the second steam supply unit in the conveyance direction. This is a steam rice cooking device characterized by the above.

[0014] This allows the rice to be heated while the excess moisture adhering to the surface of the rice in the second steam supply unit is evaporated by the superheated steam supplied by the second superheated steam supply unit. This prevents the surface of the rice from becoming soggy due to excess moisture, and allows the production of delicious rice that maintains a moderate level of moisture.

[0015] The third invention is the first or second invention, At least one of the first steaming conveyor and the second steaming conveyor, a pair of drums rotating on the upstream and downstream sides in the conveying direction; An endless net hung on the pair of drums; a sprocket that is coaxial with at least one of the pair of drums and rotates synchronously with the drum; an endless chain composed of a plurality of links connected to the net on both sides in a horizontal direction perpendicular to the conveying direction and driven by the rotating sprocket; Equipped with The cross section of the drum, which is coaxial with the sprocket and rotates in synchronization with the sprocket, perpendicular to the axial direction is formed into a polygonal shape with the length of one side corresponding to the pitch length of the links that make up the chain. This is a steam rice cooking device characterized by the above.

[0016] This allows the net to be reliably driven by an endless chain driven by a sprocket, and also suppresses distortion of the net caused by the sprocket, which occurs when the cross-sectional shape perpendicular to the axial direction of the drum is circular, thereby extending the life of the net and ultimately the life of the entire device.

[0017] The fourth invention is a first soaking step in which polished rice is soaked in soaking water for a predetermined time; a primary steaming step in which the polished rice that has been subjected to the primary soaking step is stacked on a conveying surface of a conveyor and brought into contact with steam while being conveyed; a second soaking step in which the polished rice that has been subjected to the first steaming step is placed in soaking water at a predetermined temperature and soaked for a predetermined time while being transported by a conveyor; a secondary steaming step in which the polished rice that has been subjected to the secondary soaking step is stacked on the conveying surface of a conveyor and conveyed while being exposed to steam to complete gelatinization of the polished rice; Including, The second steaming step is a first superheated steam supply step in which superheated steam is brought into contact with the polished rice that has been subjected to the second soaking step to heat the polished rice while evaporating moisture adhering to the polished rice; and a steam supplying step of contacting steam with the polished rice that has been subjected to the first superheated steam supplying step to gelatinize the polished rice. This is a method for producing cooked rice characterized by the above.

[0018] As a result, in the first superheated steam supply step of the secondary steaming step, superheated steam is brought into contact with the white rice, evaporating the moisture adhering to the surface of the white rice while heating the white rice and evaporating the moisture inside the white rice, forming multiple cavities on the surface of the white rice. Then, by supplying steam to the white rice in the steam supply step, steam is supplied into the cavities formed on the surface of the white rice, which promotes gelatinization of the white rice. Furthermore, by supplying steam into the cavities formed on the surface of the white rice, steam reaches the inside of the white rice, making it possible to produce truly delicious rice that is gelatinized all the way to the core.

[0019] The fifth invention is the fourth invention, The second steaming step is After the steam supplying step, the method further includes a second superheated steam supplying step in which the rice is further brought into contact with superheated steam to heat the rice while evaporating the moisture adhering to the rice in the steam supplying step. This is a method for producing cooked rice characterized by the above.

[0020] This allows the rice to be heated while the excess moisture that adheres to the surface of the rice in the steam supplying step is evaporated by the superheated steam supplied in the second superheated steam supplying step. This prevents the surface of the rice from becoming soggy due to excess moisture, and allows the production of delicious rice that can maintain a moderately gelatinized state even after a long period of time.

[0021] (Embodiment 1) (Overview of steam rice cooker) First, the basic configuration of a steam rice cooker 1 according to a first embodiment of the present invention will be described with reference to the drawings.

[0022] As shown in FIGS. 1 to 3 and 10, the steam rice cooker 1 includes: A front-end process section 10 supplies stored white rice R (shown by dotted hatching in each drawing), washes the rice, and causes it to flow downstream; a primary soaking section 20 in which the polished rice R washed in the pre-processing section 10 is soaked in primary soaking water W1 stored in a primary soaking tank 21 for a predetermined time; The polished rice R soaked for a predetermined time in the primary soaking unit 20 is stored in a rice storage tank 33, and the ridge forming unit 30 stacks and supplies the rice to a primary steaming conveyor (conveyor) 41. a primary steaming section 40 that stacks and conveys the polished rice R supplied from the ridge forming section 30 on a conveying surface 41a of a primary steaming conveyor 41, and supplies steam V to the polished rice R from a first steam supplying section 50 provided between the outward and return paths of the primary steaming conveyor 41; A secondary soaking section 60 flows the white rice R steamed in the primary steaming section 40 into secondary soaking water W2 at a predetermined temperature stored in a secondary soaking tank 61, and soaks the rice for a predetermined time while transporting it downstream; a secondary steaming section 70 in which the polished rice R soaked in the secondary soaking section 60 is stacked and conveyed on a conveying surface 71a of a secondary steaming conveyor (conveyor) 71, and superheated steam V1, V3 and steam V2 are supplied from between the outbound and inbound paths of the secondary steaming conveyor 71 to complete the gelatinization (gelatinization) of the polished rice R; A take-out section 115 takes out the rice R', which is white rice that has been gelatinized in the secondary steaming section 70, into a take-out container 117; It is equipped with:

[0023] (Front process section) As shown in FIG. 2, the front-end process section 10 includes: A rice silo 11 that stores white rice R to be cooked by the steam rice cooking device 1 and outputs only the required amount of rice by a rice output device 12 located at the bottom; The rice washer 14 uses air sucked by a blower 13 to send the white rice R discharged from the rice silo 11 through a rice distribution pipe 16 in the previous process, supplies clean water, i.e., rice washing water, to the delivered white rice R, and agitates the white rice R to wash it. A front-end pump 15 flows the white rice R washed by the rice washer 14 downstream through a front-end rice conveying pipe 17 using the discharged clean water; The rice washer 14 is provided with, for example, a spiral screw 14a inside.

[0024] (Primary immersion part) As shown in FIG. 3, the primary immersion section 20 includes: a primary soaking tank 21 that stores a predetermined amount of clean water, i.e., primary soaking water W1, and soaks polished rice R washed by a rice washer 14 for a predetermined time; A valve 22 is provided at the bottom of the primary soaking tank 21, and when opened, causes the polished rice R that has been soaked for a predetermined time to flow into the primary soaking rice conveying pipe 23 together with the primary soaking water W1. By opening this valve 22, the polished rice R flows into the primary submerged rice conveying pipe 23, and the primary submerged pump 24 causes the polished rice R to flow downstream by the discharged fresh water. The configuration of the valve 22 is not particularly limited, and it may be opened and closed manually or automatically.

[0025] (ridge forming part) As shown enlarged in FIGS. 1 and 4, the ridge forming portion 30 is a receiving conveyor 31 that receives the polished rice R that has been soaked in the primary soaking section 20 and flowed by the primary soaking rice conveying pipe 23, and conveys the polished rice R downstream while separating the primary soaking water W1 from the polished rice R; A rice storage tank 33 in which the polished rice R transported by the receiving conveyor 31 is dropped and stored; a polished rice supply opening 34 provided at the bottom of the rice storage tank 33 and supplying polished rice R stored in the rice storage tank 33 to the conveying surface 41a of the primary steaming conveyor 41 of the primary steaming section 40; a ridge forming plate 35 that is provided in the polished rice supply opening 34 so as to be movable up and down by a drive mechanism 36, and that adjusts the amount of polished rice R that is stacked and supplied from the polished rice supply opening 34 to the primary steaming conveyor 41, and that forms peaks RM and valleys RV on top of the polished rice R that has been stacked and supplied; (See Figure 12.)

[0026] The ridge-forming plate 35 is made of, for example, a stainless steel plate that has been cut and bent by press working or the like, and has a plurality of pointed valley-forming portions 35a that protrude downward and ridge-forming portions 35b that are recessed upward. The inclination angle of the valley-forming portions 35a from the horizontal plane is preferably 5 to 40 degrees.

[0027] The drive mechanism 36 is configured to be able to finely adjust the lower edge of the ridge forming plate 35 to an optimal vertical position using, for example, a handle 36a and a transmission mechanism 36b. The depth and width of the valley forming portions 35a and mountain forming portions 35b of the ridge forming plate 35 can be set depending on the width of the primary steaming conveyor 41, the feed speed, the stack height of the polished rice R, etc. The number of ridges of the polished rice R formed (raised portions, shown by imaginary lines in FIG. 4) may be four as in this embodiment, but the number is not particularly limited and may be any number equal to or greater than two.

[0028] 1, the receiving conveyor 31, which is provided above the rice storage tank 33 with an open top, is configured to rise from the upstream side to the downstream side. As a result, the polished rice R discharged onto the receiving conveyor 31 from the discharge port 32 provided on the upstream side of the receiving conveyor 31 is transported and rises, and the primary soaking water W1 discharged onto the receiving conveyor 31 together with the polished rice R flows toward the upstream side of the receiving conveyor 31 and is drained through the drain pipe 31a.

[0029] (Primary steaming section) As shown in FIGS. 1, 4, and 5, the primary steaming section 40 includes: a primary steaming conveyor 41 that stacks and conveys the polished rice R supplied from the ridge forming unit 30 on a conveying surface 41a (not shown in FIG. 5) while primarily steaming the polished rice R with steam; a first steam supply unit 50 that is provided between the outward path and the return path of the primary steaming conveyor 41 and supplies steam V to the polished rice R that is stacked and conveyed on the conveying surface 41a of the primary steaming conveyor 41; removable partition plates 48 (omitted in FIG. 4 and shown by imaginary lines in FIG. 5) that prevent the white rice R, which is stacked and transported on the transport surface 41a of the primary steaming conveyor 41, from falling onto the floor of the facility from both sides of the primary steaming conveyor 41, which are in directions perpendicular to the transport direction; It is equipped with:

[0030] Although not shown in detail, the partition plates 48 on both sides in the width direction are covered from above with lid members 49 (shown only in FIG. 1) with handles to prevent the escape of steam V as much as possible. The partition plates 48 are made of, for example, plate members that have been embossed to create an uneven surface to prevent polished rice R from adhering.

[0031] As shown in FIGS. 1 and 5, the primary steaming conveyor 41 is A driven drum (drum) 45 having sprockets 45a and 45b coaxially attached to both ends thereof on the upstream side thereof; Downstream of the drum 46, sprockets 46a and 46b are coaxially attached to both ends of the drum 46, which is rotated by a drive motor 46c. A driven drum (drum) 47 that rotates below the polygonal drum 46; It is equipped with:

[0032] An endless net 42 (shown in FIG. 8) is driven in a circulating manner by driven drum 45, polygonal drum 46, and driven drum 47. Net 42 is made of, for example, a flexible stainless steel net that is smaller than the grains of polished rice R and has mesh or through-holes that allow steam to pass through.

[0033] Sprockets 45a, 45b, 46a, and 46b attached to both ends of the driven drum 45 and polygonal drum 46 drive endless chains 43 and 44, each made up of a plurality of links, in a circular motion.

[0034] The polygonal drum 46 rotates in synchronization with sprockets 46a and 46b at both ends. For example, as shown in an enlarged view in Figure 8, the chains 43 and 44 are double-pitch chains with a pitch length L2 that is longer than normal.

[0035] 5, the cross section of the polygonal drum 46 in a direction perpendicular to the axial direction is a polygon, for example, a regular heptagon, and the length L1 of one side of the polygon is approximately equal to the pitch length L2 (shown in FIG. 8) of the chains 43, 44. The cross-sectional shape may also be a regular pentagon, a regular octagon, or the like.

[0036] Between the polygonal drum 46 and the sprockets 46a, 46b at both ends, there is provided a net non-contact section 46d with a circular cross section perpendicular to the axial direction. When the net 42 is driven in a circulating manner, there is a section where the net 42 located on the polygonal drum 46 is driven in contact with the polygonal drum 46, and a section where the net 42 located on the net non-contact section 46d does not come into contact with the drum.

[0037] 8, the widthwise ends of the net 42 are connected to the chains 43, 44 by connecting members 42a via ears 43a, 44a provided on the chains 43, 44. The ears 43a, 44a are located on the undersides of the net 42 of the chains 43, 44, and are connected by inserting connecting members 42a, such as rivets, through the chains 43, 44 from the top of the net 42 and crimping them. As a result, when the chains 43, 44 are driven, the net 42 is also driven at the same time, and the chains 43, 44 suppress slippage and meandering when the net 42 is driven by the polygonal drum 46, achieving a stable conveying speed and eliminating the need for meandering adjustments.

[0038] (First steam supply section) As shown in FIGS. 5 to 7, the first steam supply unit 50 includes: a water tank 51 having an open top for storing fresh water 51a; a steam supply pipe 52 that allows steam supplied from a boiler installed in the facility to flow through a steam pipe 53 and dissipates the steam in fresh water 51a stored in a water tank 51; a first steam concentrating plate 54 having a plurality of vent holes (steam supply openings) 54a attached to close the open top of the water tank 51; a second steam concentrating plate 55 provided between the first steam concentrating plate 54 and the outward path of the primary steaming conveyor 41, and having openings (steam supply openings) 55a for guiding the flow of steam V passing through a plurality of vent holes 54a provided in the first steam concentrating plate 54; It has.

[0039] 7, for example, steam emitted from a steam supply pipe 52 made of a sparge pipe (silencer) heats fresh water 51a stored in a water storage tank 51, thereby generating steam V with higher humidity than steam emitted directly from the steam supply pipe 52. This can promote gelatinization of the polished rice R that is conveyed in a stack on the conveying surface 41a of the primary steaming conveyor 41.

[0040] 6, the multiple vent holes 54a in the first steam concentrating plate 54 are densely spaced, for example, with a certain width and a longitudinal direction in the conveying direction, centered on a position that divides the width direction, perpendicular to the conveying direction of the primary steaming conveyor 41, into approximately four equal parts. For example, the first steam concentrating plate 54 is made of a thin plate of SUS304 with a plate thickness of 1 mm, and the multiple vent holes 54a are punched in predetermined areas.

[0041] The second steam concentrating plate 55 is provided with an opening 55a extending in the conveying direction through which the steam V passes through the multiple ventilation holes 54a in the first steam concentrating plate 54, and the length of the opening 55a in the width direction perpendicular to the conveying direction is narrower than the width of a predetermined area in the first steam concentrating plate 54 in which the multiple ventilation holes 54a are formed, in the direction perpendicular to the conveying direction.

[0042] The steam supply openings are made up of the multiple vent holes 54a and openings 55a. The steam supply openings 54a, 55a are configured to extend along the valleys RV formed by the ridge forming unit 30 on the upper part of the polished rice R stacked in the primary steaming step S20, which will be described later.

[0043] (Secondary immersion part) As shown in FIG. 1, the secondary immersion section 60 includes: a secondary soaking tank 61 for storing secondary soaking water W2 at a predetermined temperature supplied from a water heater provided in the facility where the steam rice cooker 1 is installed; an endless scraper conveyor (conveyor) 62 provided in the secondary soaking tank 61, which conveys the polished rice R introduced into the secondary soaking tank 61 downstream in the secondary soaking water W2 by a conveying plate 68 that circulates in an upright state; The conveying plate 68 is made of a plate member that has been embossed to have an uneven surface so that the polished rice R does not easily adhere to it.

[0044] Although detailed explanation will be omitted, the scraper conveyor 62 has a pair of rotating shafts 65, 67 and a drive shaft 66, and the base ends of numerous conveying plates 68 are connected to a pair of widthwise chains 63, 64 that are hung on these sprockets 65a, 65b, 66a, 66b, 67a, 67b. By rotating the drive shaft 66 at a predetermined speed, the conveying plates 68 move at the predetermined speed and push and convey the white rice R immersed in the secondary soaking water W2.

[0045] (Secondary steaming section) As shown in FIGS. 1 and 9, the secondary steaming section 70 includes: a secondary steaming conveyor 71 that stacks and conveys the polished rice R conveyed from the secondary soaking tank 61 of the secondary soaking section 60 on a conveying surface 71a, and secondarily steams the polished rice R with superheated steam V1, V3 and steam V2; a first loosening blade 79 for loosening the polished rice R that is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71; a first superheated steam supply unit 90 that is provided between the outward path and the return path of the secondary steaming conveyor 71 and supplies superheated steam V1 to the polished rice R that is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71; a second steam supply unit 100 that is provided between the outward path and the return path of the secondary steaming conveyor 71 and that supplies steam V2 to the polished rice R that is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71 downstream of the first superheated steam supply unit 90; a second superheated steam supply unit 110 that is provided between the outward path and the return path of the secondary steaming conveyor 71 and that supplies superheated steam V3 to the polished rice R that is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71 downstream of the second steam supply unit 100; a removable partition plate 78 that prevents the white rice R, which is stacked and transported on the transport surface 71a of the secondary steaming conveyor 71, from falling onto the floor of the facility from both sides of the secondary steaming conveyor 71, which are in a direction perpendicular to the transport direction; a second loosening blade 80 for loosening the steam-cooked white rice R' that is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71; Although not shown in detail, the area surrounded by the partition plate 78 is covered with a lid member 81 having a handle.

[0046] As shown in FIGS. 1, 8 and 10, the secondary steaming conveyor 71 is A driven drum (drum) 75 having sprockets 75a and 75b coaxially attached to both ends thereof on the upstream side thereof; Downstream of the drum 76, sprockets 76a and 76b are coaxially attached to both ends of the drum 76, which is rotated by a drive motor 76c. A driven drum (drum) 77 that rotates below the polygonal drum 76; An endless net 72 that is driven in a circular manner by a driven drum 75, a polygonal drum 76, and a driven drum 77; endless chains 73 and 74 made up of a plurality of links that are driven in a circular manner by sprockets 75a, 75b, 76a, and 76b attached to both ends of a driven drum 75 and a polygonal drum 76; The polygonal drum 76 rotates in synchronization with sprockets 76a and 76b at both ends.

[0047] Although not shown in detail, as simply shown in Figure 10, in the secondary steaming conveyor 71, similar to the polygonal drum 46 shown in Figure 5, the cross section of the polygonal drum 76 in a direction perpendicular to the axial direction is polygonal, for example a regular heptagon, and the length L1 of one side of the polygon is configured to be approximately equal to the pitch length L2 of the chains 73, 74. In addition, between the polygonal drum 76 and the sprockets 76a, 76b at both ends, there are provided net non-contact portions 76d having a circular cross section in a direction perpendicular to the axial direction.

[0048] 8, in the secondary steaming conveyor 71, the net 72 and the chains 73, 74 are connected by a connecting member 72a via ears 73a, 74a provided on the chains 73, 74.

[0049] As shown in FIG. 1, the first loosening blade 79 having a plurality of rod-shaped blades 79a is configured to loosen the white rice R scraped by the scraper conveyor 62 from the secondary soaking water W2 stored in the secondary soaking tank 61 of the secondary soaking section 60 while stacking and transporting the white rice R on the conveying surface 71a of the secondary steaming conveyor 71.

[0050] (First superheated steam supply section) As shown in FIGS. 1 and 9, the first superheated steam supply unit 90 provided between the outward and return paths of the secondary steaming conveyor 71 is a first superheated steam supply box 91 with an open top, which is provided between the outward and return paths of the secondary steaming conveyor 71; a steam supply pipe 92 that dissipates steam supplied from a boiler installed in the facility via a steam pipe 94 downward; a heater 93 for heating steam supplied from a steam supply pipe 92 to generate superheated steam V1; It is equipped with:

[0051] (Second steam supply section) As shown in FIGS. 1 and 9, the second steam supply unit 100 provided downstream of the first superheated steam supply unit 90 between the forward and return paths of the secondary steam conveyor 71 is a water tank 101 having an open top for storing fresh water 101a; a steam supply pipe 102 that allows steam from a boiler installed in the facility to flow through a steam pipe 103 and dissipate in fresh water 101a stored in a water tank 101; It has.

[0052] The steam emitted from the steam supply pipe 102 heats the fresh water 101a stored in the water tank 101, generating steam V2 with higher humidity. This promotes gelatinization of the polished rice R stacked on the conveying surface 71a of the secondary steaming conveyor 71.

[0053] (Second superheated steam supply section) As shown in FIGS. 1 and 9, the second superheated steam supply unit 110 provided downstream of the second steam supply unit 100 between the forward and return paths of the secondary steam conveyor 71 is a second superheated steam supply box 111 with an open top, which is provided between the outward path and the return path of the secondary steaming conveyor 71; a steam supply pipe 112 that dissipates steam downward from a boiler installed in the facility via a steam pipe 114; a heater 113 for heating steam supplied from a steam supply pipe 112 to generate superheated steam V3; It is equipped with:

[0054] (Removal part) Although detailed explanation will be omitted, as shown in FIG. 10, the take-out section 115 is equipped with a take-out conveyor 116 that transports the rice R' loosened by the second loosening blade 80 having multiple rod-shaped blades 80a of the secondary steaming section 70 and stores it in a take-out container 117.

[0055] (Outline of the manufacturing method of cooked rice) Next, a method for producing cooked rice using the steam rice cooker 1 will be described.

[0056] As shown in FIG. 11, the method for producing cooked rice is as follows: A pre-process step S1 in which a predetermined amount of stored white rice R is discharged and sent, washed, and sent downstream; A first soaking step S10 in which the white rice R washed in the previous step S1 is soaked in the first soaking water W1 for a predetermined time; a primary steaming step S20 in which the polished rice R soaked for a predetermined time in the primary soaking step S10 is stored, stacked on the conveying surface 41a of the primary steaming conveyor 41, and conveyed by the primary steaming conveyor 41 while supplying steam V for a predetermined time to bring the polished rice R into contact with the polished rice R; A second soaking step S30 in which the white rice R to which steam V has been supplied for a predetermined time in the first steaming step S20 is soaked for a predetermined time while being transported in the second soaking water W2; a secondary steaming step S40 in which the polished rice R soaked for a predetermined time in the secondary soaking step S30 is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71, and superheated steam V1, V3 and steam V2 are supplied for a predetermined time to contact the polished rice R and complete gelatinization of the polished rice R; A take-out step S50 of taking out the rice R', which is white rice that has been gelatinized in the secondary steaming step S40, into a take-out container 117; It is equipped with:

[0057] Furthermore, the secondary steaming step S40 is a first superheated steam supply step S41 in which superheated steam V1 is supplied to the polished rice R that is stacked and transported on the transport surface 71a of the secondary steaming conveyor 71; After the first superheated steam supply step S41, a steam supply step S42 is performed in which steam V2 is supplied to the polished rice R that is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71. After the steam supplying step S42, a second superheated steam supplying step S43 is performed in which superheated steam V3 is supplied to the polished rice R that is stacked and transported on the transport surface 71a of the secondary steaming conveyor 71. It is equipped with:

[0058] (Pre-process step) The first pre-process step S1 will be described.

[0059] First, as shown in Figure 2, polished rice R to be steam cooked in the steam rice cooker 1 of the present invention is discharged from a rice silo 11 by a rice discharge device 12. The discharged polished rice R is transported by air sucked in by a blower 13, and is sent to a rice washing machine 14 downstream through a previous process rice distribution pipe 16.

[0060] The polished rice R sent to the rice washer 14 is washed by being stirred by the screw 14a together with the washing water supplied inside the rice washer 14. The washed polished rice R is sent to the previous process rice sending pipe 17 together with the washing water, and is sent downstream together with the clean water discharged by the previous process pump 15.

[0061] (First immersion step) The primary immersion step S10, which follows the pre-process step S1, will now be described.

[0062] As shown in FIG. 3, polished rice R sent together with rice-washing water in the previous step S1 is sent to a first soaking tank 21.

[0063] The polished rice R sent to the primary soaking tank 21 is immersed in the primary soaking water W1 stored in the primary soaking tank 21. The polished rice R immersed in the primary soaking water W1 stored in the primary soaking tank 21 is soaked for a predetermined time, for example, approximately 60 minutes.

[0064] After soaking for a predetermined time, the valve 22 at the bottom of the primary soaking tank 21 is opened, and the white rice R and primary soaking water W1 are sent to the primary soaking rice sending pipe 23 by their own weight.

[0065] As shown in FIG. 3, by opening the valve 22 at the bottom of the primary soaking tank 21, the white rice R and primary soaking water W1 are sent by gravity to the primary soaking rice conveying pipe 23, and the rice is sent downstream by the force of the fresh water discharged by the primary soaking pump 24.

[0066] (First steaming step) The primary steaming step S20, which follows the primary soaking step S10, will now be described.

[0067] As shown in Figures 1 and 4, the polished rice R sent downstream by the primary submerged rice sending pipe 23 falls from the discharge outlet 32 ​​onto the conveying surface of the receiving conveyor 31 provided above the rice storage tank 33.

[0068] The receiving conveyor 31 transports the white rice R to the upwardly inclined downstream side, and at the lower side, which is the upstream side of the receiving conveyor 31, the first soaking water W1 and clean water that have flowed onto the conveying surface of the receiving conveyor 31 together with the white rice R are separated from the white rice R and drained into the drain pipe 31a.

[0069] The polished rice R from which the primary soaking water W1 and the clean water have been separated drops from the downstream side of the receiving conveyor 31 into the rice storage tank 33. The polished rice R that drops and is stored in the rice storage tank 33 is supplied in a stack from the polished rice supply opening 34 provided at the bottom of the rice storage tank 33 onto the conveying surface 41a of the primary steaming conveyor 41.

[0070] The polished rice R supplied in a stacked manner to the transport surface 41a of the primary steaming conveyor 41 is stacked in such a way that it bulges upward so that its cross section in the direction perpendicular to the transport direction of the primary steaming conveyor 41 is semi-cylindrical. Then, by the ridge forming plate 35 provided in the polished rice supply opening 34 so as to be movable up and down, peaks RM and valleys RV are formed on the top of the polished rice R stacked in a semi-cylindrical cross section, as shown by imaginary lines in Fig. 4 or by thick lines in Fig. 12, and the polished rice R is supplied in a stacked manner to the transport surface 41a of the primary steaming conveyor 41.

[0071] The white rice R is stacked and supplied onto the conveying surface 41a of the primary steaming conveyor 41, and while being conveyed by the primary steaming conveyor 41, steam V is supplied from an opening 55a of the first steam supply section 50 located between the outbound and return paths of the primary steaming conveyor 41.

[0072] The steam V supplied from the opening 55a of the first steam supply unit 50 flows between the polished rice R stacked on the transfer surface 41a of the primary steaming conveyor 41, and comes into contact with the polished rice R to supply heat and moisture to the polished rice R. The steam V then gelatinizes the polished rice R, passes through the polished rice R stacked on the transfer surface 41a of the primary steaming conveyor 41, and is released into the atmosphere from above the polished rice R.

[0073] Steam V is supplied to the polished rice R, which is stacked and transported on the transport surface 41a of the primary steaming conveyor 41, for a predetermined time, for example, about 10 minutes, and then the polished rice R is dropped from the transport surface 41a of the primary steaming conveyor 41 into the secondary soaking tank 61 downstream, as shown in FIG. 1.

[0074] (Furrow forming effect) In the primary steaming step S20, peaks RM and valleys RV are formed by the ridge forming plate 35 on the upper part of the polished rice R stacked on the conveying surface 41a of the primary steaming conveyor 41, forming the rice into a plurality of ridges. The effects of forming the peaks RM and valleys RV will now be described.

[0075] As shown in FIG. 12, from the start of the primary steaming step S20 until a predetermined time has elapsed, the steam V supplied from the opening 55a into the polished rice R passes through the polished rice R stacked on the conveying surface 41a in a substantially straight line toward the valleys RV, and is dissipated mainly from the bottoms of the valleys RV into the atmosphere.

[0076] Then, of the white rice R stacked on the conveying surface 41a, the white rice R between the point where it comes into contact with the conveying surface 41a located above the multiple ventilation holes 54a in the first steam concentrating plate 54 and the openings 55a in the second steam concentrating plate 55, and the bottom of the valley portion RV can be intensively gelatinized and swollen.

[0077] Steam V passing through the concentrated gelatinized and swollen white rice R gradually gelatinizes and swells the white rice R adjacent to the area it passes through. The swollen white rice R widens the gaps between the white rice R, expanding the area through which steam V can pass.

[0078] As shown in FIG. 13, after a predetermined time has elapsed since the start of the primary steaming step S20, steam V can pass through the entire polished rice R stacked on the conveying surface 41a in a cross section perpendicular to the conveying direction of the primary steaming conveyor 41.

[0079] The steam V passing through the entirety of the polished rice R stacked on the conveying surface 41a spreads throughout the polished rice R in the cross section perpendicular to the conveying direction of the primary steaming conveyor 41 and is dispersed into the atmosphere from the entire upper part of the polished rice R. This allows the polished rice R stacked on the conveying surface 41a to be gelatinized evenly in the cross section perpendicular to the conveying direction of the primary steaming conveyor 41.

[0080] Previously, when the thickness of the white rice stacked on the conveying surface of the primary steaming conveyor was thick in the vertical direction from the top edge to the conveying surface, the steam supplied from the steam supply unit would not pass through the rice and would escape to the side of the primary steaming conveyor, making it impossible to reliably gelatinize the white rice.

[0081] In the present invention, the vertical thickness from the bottom of the valley portion RV to the conveying surface 41a of the primary steaming conveyor 41 is set to a thickness L3 that allows the steam V to pass through, so that even if the vertical thickness of the polished rice R stacked on the conveying surface 41a is thick, the steam V can pass through the polished rice R, and the polished rice R can be gelatinized.

[0082] Then, after a predetermined time has elapsed since the start of the primary steaming step S20, the steam V passes through the entire polished rice R stacked on the conveying surface 41a in the cross section perpendicular to the conveying direction of the primary steaming conveyor 41, and the entire polished rice R can be gelatinized.

[0083] In the steam rice cooker 1 described in this embodiment, for example, the vertical thickness L3 from the bottom of the valley portion RV to the conveying surface 41a of the primary steaming conveyor 41 is set to approximately 140 mm. This thickness L3 is preferably adjusted according to the variety, quality, moisture content, etc. of the polished rice R.

[0084] Furthermore, as shown in FIG. 13, after a predetermined time has elapsed since the start of the primary steaming step S20, the white rice R stacked on the conveying surface 41a swells, so that the thickness of the entire white rice R increases in a cross section perpendicular to the conveying direction of the primary steaming conveyor 41, and the thickness L3 changes to a thickness L4 that is thicker than the thickness L3, and the vertical height of the recessed portion of the valley portion RV decreases.

[0085] This allows the steam V passing through the white rice R from the point where it comes into contact with the conveying surface 41a located above the multiple ventilation holes 54a in the first steam concentrating plate 54 and the openings 55a in the second steam concentrating plate 55 to the bottom of the valley portion RV to remain in the white rice R for a longer period of time and be dispersed within the white rice R, thereby enabling a large amount of white rice R to be gelatinized.

[0086] The specified time required for the steam V to reach the entire polished rice R stacked on the conveying surface 41a in a cross section perpendicular to the conveying direction of the primary steaming conveyor 41 varies depending on the variety, quality, moisture content, thicknesses L3 and L4, etc. of the polished rice R, but it is preferable to set the time as short as possible to promote gelatinization of the polished rice R.

[0087] (Polygonal drum effect) Generally, when a chain is driven using a sprocket, the radius from the center of the rotation axis differs between the sprockets at both ends of each link of the chain and the middle of each link, and this causes the chain's driving speed to fluctuate each time the sprocket rotates a certain angle. This is particularly noticeable when the sprocket has a small number of teeth.

[0088] Furthermore, since the space within the facility where the steam rice cooker 1 of this embodiment is installed is limited, it is necessary to make the configuration of the steam rice cooker 1 as small as possible. Therefore, it is also necessary to make the configuration of the primary steaming section 40 as small as possible, and there is an urgent need to make the sprockets 45a, 45b, 46a, 46b of the primary steaming conveyor 41 small as well.

[0089] In particular, as shown in Figure 1, downstream of the conveyor that transports white rice R, the conveyor for the next process can be positioned below the discharge position of the white rice R with a small difference in height between the conveyor transport surfaces on the upstream and downstream sides, allowing the white rice R to be transported reliably to the next process.

[0090] Even in the steam rice cooker 1 of this embodiment, the sprockets 45a, 45b, 46a, and 46b need to be as small as possible, so the radius from the center of the rotation axis differs between the end portions and the middle portion of each link of the chains 43 and 44, and there is a risk that the speed at which the chains 43 and 44 circulate will fluctuate each time the sprockets 45a, 45b, 46a, and 46b rotate a predetermined angle.

[0091] The chains 43, 44 and the net 42 are connected by connecting members 42a at ears 43a, 44a located in the middle of each link of the chains 43, 44. The chains 43, 44 are driven by sprockets 46a, 46b, and the radius from the center of the rotation axis is different between the portions of each link of the chains 43, 44 that are hooked onto the sprockets 46a, 46b at both ends and the middle portions of each link.

[0092] On the other hand, when the net 42 is driven by a circular drum, the radius from the center of the rotation axis is constant. When driven by a circular drum, the chains 43, 44 and the net 42 have different radii from the center of the rotation axis, so excessive tension is applied to the parts connecting the chains 43, 44 and the net 42 with the connecting members 42a, causing distortion in the circulating net 42.

[0093] 5 and 8, in the present invention, the length L1 of one side of the polygon of the polygonal drum 46 provided downstream in the conveying direction of the polished rice R of the primary steaming conveyor 41 is set to be approximately equal to the pitch length L2 of the chains 43, 44. Note that "approximately equal" means that there may be a difference larger than the design error, for example, a difference of about ±1 to ±3 mm.

[0094] The size of the cross section of the polygonal drum 46 in a direction perpendicular to the axial direction should be such that the length L1 of one side of the polygonal drum 46 is approximately equal to the pitch length L2 of the chains 43, 44, and the size of the circle circumscribed by the cross section of the polygonal drum 46 in a direction perpendicular to the axial direction should be approximately equal to the pitch circle diameter of the sprockets 46a, 46b.

[0095] This allows the net 42 to be driven in a polygonal shape, and the radius from the center of the rotation axis can be made approximately equal to that of the chains 43, 44. The circulation speed of the net 42 can be intentionally changed in accordance with the fluctuations in the circulation speed of the chains 43, 44 and their timing.

[0096] Furthermore, a net non-contact portion 46d with a circular cross section in a direction perpendicular to the axial direction is provided between the polygonal drum 46 and the sprockets 46a, 46b at both ends. This prevents the net 42 located at the net non-contact portion 46d from contacting the drum, and even if there is a difference between the length L1 of one side of the polygonal drum 46 and the pitch length L2 of the chains 43, 44, it is possible to release the tension applied to the portion where the chains 43, 44 and the net 42 are connected by the connecting member 42a.

[0097] In this way, distortion occurring in the net 42 at the portion where the chains 43, 44 and the net 42 are connected by the connecting member 42a can be suppressed, thereby extending the life of the net 42 and ultimately the life of the steam rice cooker 1.

[0098] (Effects of the first steam concentrating plate and the second steam concentrating plate) 6 and 12, the flow of steam V generated in the first steam supply unit 50 can be concentrated in the width direction perpendicular to the conveyance direction by the plurality of ventilation holes 54a in the first steam concentrating plate 54. Then, the openings 55a in the second steam concentrating plate 55 can further concentrate the flow of steam V in the width direction perpendicular to the conveyance direction.

[0099] In this way, the steam V generated from almost the entire surface of the fresh water 51a stored in the water tank 51 can be concentrated in the width direction perpendicular to the conveyance direction with a simple configuration by simply passing the steam V through the upper and lower two-stage steam supply openings 54a, 55a. The flow of steam V concentrated in this way is sprayed onto the net 42 located directly below the valleys RV formed at the top of the polished rice R being conveyed in a stack on the conveyance surface 41a of the primary steaming conveyor 41.

[0100] This allows more steam V to flow into and pass through the polished rice R that is stacked and transported on the transport surface 41a of the primary steaming conveyor 41, and the steam V can be supplied to the polished rice R more effectively.

[0101] (Second immersion step) The secondary soaking step S30, which follows the primary steaming step S20, will now be described.

[0102] 1, the polished rice R that has completed the primary steaming step S20 is transported by the primary steaming conveyor 41 to the secondary soaking tank 61. The polished rice R is soaked for a predetermined time, for example, approximately 8 minutes, in the secondary soaking water W2 stored in the secondary soaking tank 61 and having a predetermined temperature, for example, 91 to 95 degrees C, while being transported downstream by the scraper conveyor 62.

[0103] After the white rice R in the secondary soaking water W2 stored in the secondary soaking tank 61 is soaked for a predetermined time, it is scraped out of the secondary soaking tank 61 by a scraper conveyor 62 and transported onto the transport surface 71a of the secondary steaming conveyor 71 in the secondary steaming section 70, where it is stacked.

[0104] (Second steaming step) The secondary steaming step S40, which follows the secondary soaking step S30, will now be described. The secondary steaming step S40 includes a first superheated steam supplying step S41, a steam supplying step S42, and a second superheated steam supplying step S43.

[0105] (First superheated steam supply step) First, the first superheated steam supply step S41, which is the first step in the secondary steaming step S40, will be described.

[0106] As shown in FIG. 1, the polished rice R that is intermittently scraped out of the secondary soaking tank 61 and piled up on the conveying surface 71a of the secondary steaming conveyor 71 is loosened by the rotating first loosening blade 79 while being transported by the secondary steaming conveyor 71.

[0107] This makes it possible to make the height of the upper surface of the polished rice R that is stacked and transported on the transport surface 71a of the secondary steaming conveyor 71 as uniform as possible. Then, when the superheated steam V1, V3 and steam V2 that are supplied from between the outbound and inbound routes of the secondary steaming conveyor 71 are supplied into the polished rice R stacked on the transport surface 71a of the secondary steaming conveyor 71, the superheated steam V1, V3 and steam V2 are supplied as uniformly as possible to the polished rice R and brought into contact with the polished rice R, thereby enabling the polished rice R to be gelatinized evenly.

[0108] Furthermore, by loosening the white rice R with the rotating first loosening blade 79, excess moisture adhering to the surface of the white rice R can be evaporated, and more gaps can be formed between the white rice R, making it easier for the superheated steam V1, V3 and steam V2 to pass through the white rice R, thereby promoting the gelatinization of the white rice R.

[0109] After being loosened by the first loosening blade 79, the white rice R is stacked and transported on the transport surface 71a of the secondary steaming conveyor 71. Superheated steam V1 is supplied to the white rice R from a first superheated steam supply unit 90 provided between the outbound and return paths of the secondary steaming conveyor 71.

[0110] Specifically, as shown in Figures 1 and 9, steam supplied from a boiler is diffused downward from a steam supply pipe 92, and the steam supplied from this steam supply pipe 92 is heated by a heater 93 to become superheated steam V1, which is then supplied.

[0111] The superheated steam V1 supplied from the first superheated steam supply unit 90 evaporates the moisture adhering to the surface of the white rice R and dissipates it into the atmosphere. As a result, the white rice R is heated while evaporating the moisture adhering to the surface of the white rice R, and the moisture inside the white rice R is evaporated, thereby forming multiple cavities on the surface of the white rice R.

[0112] (Steam supply step) Next, the steam supplying step S42 performed after the first superheated steam supplying step S41 in the secondary steaming step S40 will be described.

[0113] As shown in FIGS. 1 and 9, the polished rice R that has been stacked and transported on the transport surface 71a of the secondary steaming conveyor 71 after the first superheated steam supply step S41 is brought into contact with highly humid steam V2 supplied from a second steam supply section 100 provided between the outbound and inbound paths of the secondary steaming conveyor 71.

[0114] Specifically, the second steam supply unit 100 injects steam from a boiler downward from a steam supply pipe 102, evaporating water stored in a water tank 101 to generate steam V2 at approximately 100 degrees Celsius.

[0115] This makes it possible to supply steam V2 into the cavity formed on the surface of the white rice R in the first superheated steam supply step S41, allowing the steam V2 to reach the inside of the white rice R, producing truly delicious rice that is gelatinized to the core.

[0116] (Second superheated steam supply step) In the secondary steaming step S40, the second superheated steam supplying step S43 performed after the steam supplying step S42 will be described.

[0117] As shown in FIGS. 1 and 9, superheated steam V3 is supplied from a second superheated steam supply unit 110 provided between the outbound and inbound paths of the secondary steaming conveyor 71 to contact the white rice R that is stacked and conveyed on the conveying surface 71a of the secondary steaming conveyor 71 after the steam supply step S42.

[0118] This makes it possible to heat the white rice R while evaporating excess moisture adhering to the surface of the white rice R in the second steam supply unit 100 with the superheated steam V3 supplied by the second superheated steam supply unit 110. This prevents the surface of the white rice R from becoming soggy due to excess moisture, and allows the white rice R to maintain a state in which it retains an appropriate amount of moisture, thereby completing the gelatinization of the white rice R.

[0119] The steam V2 from the second steam supply unit 100 has a lower temperature than the superheated steams V1 and V3, and generates a larger amount of steam per unit time than the superheated steams V1 and V3.

[0120] As shown in Figures 1 and 9, after superheated steam V3 is supplied from the second superheated steam supply unit 110 to the white rice R stacked on the conveying surface 71a of the secondary steaming conveyor 71, the rice R', which is white rice that has completed gelatinization, is loosened by the rotating second loosening blade 80.

[0121] This allows air to be contained in the rice R' that is stacked and transported on the transport surface 71a of the secondary steaming conveyor 71, facilitating evaporation of excess moisture adhering to the surface of the rice R', thereby enabling the production of more delicious rice R'.

[0122] The secondary steaming step S40 consists of three steps: a first superheated steam supplying step S41, a steam supplying step S42, and a second superheated steam supplying step S43, which are carried out over a predetermined time, for example, approximately 15 minutes. The predetermined time for carrying out the secondary steaming step S40 varies depending on the amount, variety, quality, moisture content, etc. of the polished rice R piled on the conveying surface 71a of the secondary steaming conveyor 71.

[0123] In the first superheated steam supply step S41 and the second superheated steam supply step S43 that constitute the secondary steaming step S40, the temperature of the superheated steam V1, V3 supplied to the white rice R is set to a predetermined temperature, for example, between 100 degrees C and 120 degrees C.

[0124] This makes it possible to prevent discoloration of the polished rice R due to excessively high heat temperature being applied to the polished rice R. Note that the second superheated steam supplying step S43 is not necessarily provided, and the process may proceed from the steam supplying step S42 to the removal step S50.

[0125] (Polygonal drum effect) Similar to the configuration of the primary steaming conveyor 41 in the primary steaming section 40, the secondary steaming conveyor 71 in the secondary steaming section 70 drives a net 72 in a circulating manner using a driven drum 75, a polygonal drum 76, and a driven drum 77. The net 72 is connected to chains 73 and 74 by connecting members 72a on both sides of the conveying direction of the white rice R, and the net 72 is driven in a circulating manner in conjunction with the chains 73 and 74.

[0126] As a result, the secondary steaming conveyor 71 driven in circulation in the secondary steaming step S40 also achieves the same effects as those described for the primary steaming step S20. In other words, the net 72 can be driven in a polygonal shape, and the radius from the center of the rotation axis can be made approximately equal to that of the chains 73, 74. The circulation speed of the net 72 can be intentionally changed in accordance with the fluctuations in the circulation speed of the chains 73, 74 and their timing, thereby suppressing distortion of the net 72 and lengthening the lifespan of the net 72 and, ultimately, the lifespan of the steam rice cooker 1.

[0127] (Removal step) Finally, the removing step S50, which is performed after the secondary steaming step S40, will be described.

[0128] As shown in Figure 10, cooked rice R', which is white rice that has been gelatinized in the secondary steaming step S40, is taken out and transported downstream on a conveyor 116. The cooked rice R' is then dropped into a take-out container 117 installed downstream and stored therein.

[0129] (Other embodiments) The present invention may be configured as follows in relation to the above embodiment.

[0130] That is, the primary steaming conveyor 41 and the secondary steaming conveyor 71 have been described as net conveyors that circulate the nets 42, 72, but they may also be configured as belt conveyors that circulate a belt as long as they can pass the steam V, V2 and the superheated steam V1, V3 and can transport the white rice R in a stacked state on the transport surfaces 41a, 71a.

[0131] Furthermore, the steam rice cooker 1 described in this embodiment is a standard configuration, and any of the components may be omitted, added, or replaced as long as the configuration is capable of steam cooking white rice R.

[0132] Furthermore, in this embodiment, the rice to be steam-cooked is described as white rice R, but it may be brown rice or other grains that can be cooked with heat and moisture.

[0133] Although detailed explanations have been omitted in the embodiment, each component in the steam rice cooker 1 may be controlled by a control panel (not shown), and this control panel may be physically configured in any way as long as it controls the steam rice cooker 1. For example, the control panel may use software (programs), such as a microcomputer or programmable logic controller (PLC). Alternatively, the control panel may be realized by combining hardware (circuit components).

[0134] It should be noted that the above-described embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or uses. [Explanation of symbols]

[0135] 1. Steam rice cooker 10 Front-end process section 11 Rice Silo 12 Rice brewing device 13 Blower 14 Rice washing machine 14a screw 15 Front-end pump 16 Pre-process rice distribution pipe 17 Pre-process rice feeding tube 20 Primary immersion section 21 Primary immersion tank 22 Valves 23 Primary immersion rice feeding pipe 24 Primary immersion pump 30 Ridge forming part 31 Receiving conveyor 31a Drain pipe 32 Discharge port 33 Rice storage tank 34 Opening for supplying white rice 35 Ridge forming plate 35a Valley forming part 35b Mountain formation part 36 Drive mechanism 36a handle 36b Transmission mechanism 40 Primary steaming section 41 Primary steaming conveyor (conveyor) 41a Conveying surface 42 Net 42a Connecting member 43 Chain 43a Ears 44 Chain 44a Ears 45 Driven drum (drum) 45a sprocket 45b sprocket 46 Polygonal Drum (Drum) 46a sprocket 46b sprocket 46c drive motor 46d Net non-contact section 47 Driven drum (drum) 48 Partition 49 Lid member 50 First steam supply section 51 Water Tank 51a Shimizu 52 Steam supply pipe 53 Steam Pipe 54 No. 1 Steam Concentration Plate 54a Multiple vents (steam supply openings) 55 Second steam concentrator 55a Opening (steam supply opening) 60 Secondary immersion section 61 Secondary immersion tank 62 Scraper conveyor (conveyor) 63 Chain 64 Chain 65 Rotation axis 65a sprocket 65b sprocket 66 Drive shaft 66a sprocket 66b sprocket 67 Rotation axis 67a sprocket 67b sprocket 68 Transport Plate 70 Secondary steaming section 71 Secondary steaming conveyor (conveyor) 71a Conveying surface 72 net 72a Connecting member 73 Chain 73a Ears 74 Chain 74a Ears 75 Driven drum (drum) 75a sprocket 75b sprocket 76 Polygonal Drum (Drum) 76a sprocket 76b sprocket 76c drive motor 76d Net non-contact part 77 Driven drum (drum) 78 Partition 79 First loosening blade 79a Feather 80 Second loosening blade 80a feather 81 Cover member 90 First superheated steam supply section 91 First superheated steam supply box 92 Steam supply pipe 93 Heater 94 Steam Pipe 100 Second steam supply section 101 Water Tank 101a Shimizu 102 Steam supply pipe 103 Steam Pipe 110 Second superheated steam supply section 111 Second superheated steam supply box 112 Steam supply pipe 113 Heater 114 Steam Pipe 115 Removal section 116 Removal conveyor 117 Removal container S1 Front-end process step S10 First immersion step S20 First steaming step S30 Secondary Soaking Step S40 Secondary steaming step S41 First superheated steam supply step S42 Steam supply step S43 Second superheated steam supply step S50 Removal Step L1 Length of one side of the polygonal drum L2 Chain pitch length L3 thickness L4 thickness R White rice RM Yamabe RV Valley R' Rice V Steam V1 Superheated steam V2 Steam V3 Superheated Steam W1 Primary immersion water W2 Secondary immersion water

Claims

1. a pair of drums rotating on the upstream and downstream sides in the conveying direction; An endless net hung on the pair of drums; a sprocket that is coaxial with one of the pair of drums and rotates in synchronization with the drum that is rotated by the drive motor; an endless chain composed of a plurality of links connected to the net on both sides in a horizontal direction perpendicular to the conveying direction and driven by the rotating sprocket; Equipped with The drum, which is coaxial with the sprocket and rotates in synchronization with it, is a polygonal drum whose cross section perpendicular to the axial direction is formed into a polygonal shape with the length of one side corresponding to the pitch length of the links that make up the chain, The endless net located on the polygonal drum is driven in contact with the polygonal drum. A conveyor characterized by:

2. The size of the cross section of the polygonal drum in a direction perpendicular to the axial direction is such that the length of one side of the polygonal drum is approximately equal to the pitch length of the chain, and the size of the circle circumscribing the cross section of the polygonal drum in a direction perpendicular to the axial direction is approximately equal to the pitch circle diameter of the sprocket.

2. The conveyor of claim 1.

3. Between the polygonal drum and the sprocket, a non-net contact section is provided that has a circular cross section in the direction perpendicular to the axial direction and does not come into contact with the endless net.

3. A conveyor according to claim 1 or 2.

Images