Patent Publication Number: US-2023137565-A1

Title: Soybean curd production device and soybean curd production method

Description:
TECHNICAL FIELD 
     The present invention relates to a soybean curd production device including a continuous coagulation machine and a continuous forming machine, and a soybean curd production method. 
     BACKGROUND ART 
     In the related art, various soybean curd production devices each including a boat-shaped continuous coagulation machine are known (see, for example, Patent Literatures 1 to 4). 
     Patent Literatures 1 and 2 disclose that a soybean curd obtained by coagulating soymilk in an automatic coagulation unit is sent to an automatic forming unit through a feed port. In particular, Patent Literature 1 discloses that a good-quality product cannot be obtained by extremely crushing soybean curd, and thick and long soybean curd is produced without crushing the soybean curd material as much as possible, and thus sending the soybean curd into the forming unit is performed by a damper with a lever that includes a balance weight at the feed port to slowly drop the soybean curd material and to uniformize an amount of the soybean curd material. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: JP-A-551-070862 
         Patent Literature 2: JP-A-S51-106779 
         Patent Literature 3: JP-A-548-085756 
         Patent Literature 4: JP-A-548-085757 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in Patent Literatures 1 and 2, the automatic coagulation unit has a two-story structure disposed above an upper caterpillar of the automatic forming unit, and thus a difference in height between the automatic coagulation unit and the automatic forming unit is considerable and a considerable amount of the soybean curd is crushed. There is an effect of somewhat reducing a variation in feed amount when the soybean curd is sent in by the damper. However, the feed port is largely opened at the time of dropping of a large amount of the soybean curd and the feed port is closed at the time of dropping of a small amount of the soybean curd, and particularly, hardness of the soybean curd varies due to a change in soybean quality, and thus uniformity of quantity is poor. 
     The present invention has been made in view of the above problems, and an object of the present invention is to provide a soybean curd production device and a soybean curd production method capable of supplying a soymilk coagulated product from a continuous coagulation machine onto a lower fabric of a continuous forming machine without crushing the soymilk coagulated product while ensuring uniformity of quantity. 
     Solution to Problem 
     The above object of the present invention is achieved by the following configurations. 
     (1) A soybean curd production device including: 
     a continuous coagulation machine having a boat shape, the continuous coagulation machine including: 
     an endless conveyor in which a plurality of partition blades are attached to a surface of a conveyor belt at predetermined intervals, and 
     a coagulation tank having a recessed shape in a cross-section to allow the partition blades to pass through an inside of the coagulation tank; and 
     a continuous forming machine including at least:
         a lower endless conveyor around which a lower fabric is wound, and   an upper endless conveyor around which an upper fabric is wound, in which       

     the lower endless conveyor overlaps with the coagulation tank when viewed from above such that the lower fabric is located below an outlet end portion of the coagulation tank, and 
     a bottom wall of the coagulation tank is formed substantially horizontally from a vicinity of an inlet of the coagulation tank to the outlet end portion of the coagulation tank. 
     (2) The soybean curd production device according to (1), in which 
     the coagulation tank and the upper endless conveyor are linearly arranged side by side. 
     (3) The soybean curd production device according to (1) or (2), in which 
     the endless conveyor of the continuous coagulation machine is inclined upward in a feed direction of the continuous coagulation machine such that tip ends or attachment ends of the partition blades rise in a vicinity of an outlet of the coagulation tank. 
     (4) The soybean curd production device according to any one of (1) to (3), in which 
     the continuous coagulation machine has a supply port or a discharge port in at least one location of both side walls or the bottom wall of the coagulation tank in the vicinity of the inlet of the coagulation tank, the supply port of the discharge port being configured to allow any one of soymilk, a coagulant, and coagulant-containing soymilk or a cleaning chemical liquid to be supplied or discharged therethrough. 
     (5) The soybean curd production device according to (4), in which 
     the coagulation tank includes an opening and closing member configured to open and close the supply port. 
     (6) The soybean curd production device according to (5), in which 
     the opening and closing member is disposed so as to fill a recess formed in the side wall of the coagulation tank where the supply port is opened, and to flatly close the supply port. 
     (7) The soybean curd production device according to (5) or (6), in which 
     the partition blades are scrapers made of rubber, and 
     the opening and closing member is formed by the scrapers made of rubber configured to bend by contacting an inner surface of the coagulation tank to close the supply port. 
     (8) The soybean curd production device according to any one of (1) to (7), in which 
     the continuous coagulation machine is driven synchronously with the continuous forming machine. 
     (9) The soybean curd production device according to any one of (1) to (8), in which 
     a width of the coagulation tank is substantially equal to a width of a press portion of the continuous forming machine. 
     (10) The soybean curd production device according to any one of (1) to (9), in which 
     a crushing device is provided between the coagulation tank and the upper endless conveyor and above the lower fabric of the lower endless conveyor, 
     a protective plate with which the crushing device is allowed to come into contact is disposed at a position below the crushing device, and 
     the lower fabric of the lower endless conveyor is pushed downward and guided so as to avoid the protective plate. 
     (11) The soybean curd production device according to any one of (1) to (10), in which 
     the continuous coagulation machine further includes a cover that covers an upper portion of the endless conveyor. 
     (12) The soybean curd production device according to any one of (1) to (11), in which 
     in the endless conveyor, a chain connected to the conveyor belt, and a sprocket around which the chain is wound are disposed on an outside of a side wall of the coagulation tank in a width direction. 
     (13) A soybean curd production method for producing soybean curd by using the soybean curd production device according to any one of (1) to (12), the soybean curd production method comprising: 
     producing a pudding-like soymilk coagulated product using the continuous coagulation machine to coagulate and age soymilk of 50° C. to 95° C. having a solid content of 3 wt % to 20 wt % by a coagulant; and 
     forming the soybean curd using the continuous forming machine to convey the soymilk coagulated product by the lower fabric and press the soymilk coagulated product as necessary. 
     (14) The soybean curd production method according to (13), in which 
     the coagulant is a slow-acting coagulant or an emulsified bittern. 
     In the present description, the “substantially pudding-like soymilk coagulated product” refers to a state of a coagulated product after coagulation and aging, that is, a state in which water separation is 20% or less, preferably 10% or less. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to supply a soymilk coagulated product from a continuous coagulation machine onto a lower fabric of a continuous forming machine without crushing the soymilk coagulated product while ensuring uniformity of quantity. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    illustrates (a) showing a schematic top view showing a soybean curd production device according to a first embodiment of the present invention, and (b) showing a schematic side view of (a). 
         FIG.  2    is a schematic side view showing a soybean curd production device according to a first modification of the first embodiment of the present invention. 
         FIG.  3    is a schematic side view showing a soybean curd production device according to a second modification of the first embodiment of the present invention. 
         FIG.  4    is a schematic side view showing a soybean curd production device according to a third modification of the first embodiment of the present invention. 
         FIG.  5    is a schematic side view showing a soybean curd production device according to a fourth modification of the first embodiment of the present invention. 
         FIG.  6    is a schematic side view showing a soybean curd production device according to a fifth modification of the first embodiment of the present invention. 
         FIG.  7    is a schematic side view showing a soybean curd production device according to a sixth modification of the first embodiment of the present invention. 
         FIG.  8    illustrates (a) showing a schematic side view corresponding to VIII-VIII in  FIG.  1    and showing a soybean curd production device according to an example of a seventh modification of the first embodiment of the present invention, and (b) showing a schematic side view corresponding to VIII-VIII in  FIG.  1    and showing a soybean curd production device according to another example of the seventh modification of the first embodiment of the present invention. 
         FIG.  9    illustrates (a) showing a schematic top view showing a soybean curd production device according to a second embodiment of the present invention, and (b) showing a schematic side view of (a). 
         FIG.  10    illustrates cross-sectional views of a vicinity of an inlet of a continuous coagulation machine in  FIG.  9   , in which (a) shows a state in which a supply port is closed, and (b) shows a state in which the supply port is opened. 
         FIG.  11    illustrates cross-sectional views of a vicinity of an inlet of a continuous coagulation machine in a soybean curd production device according to a first modification of the second embodiment of the present invention, in which (a) shows a state in which the supply port is closed, and (b) shows a state in which the supply port is opened. 
         FIG.  12    illustrates cross-sectional views of a vicinity of an inlet of a continuous coagulation machine in a soybean curd production device according to a second modification of the second embodiment of the present invention, in which (a) shows a state in which the supply port is closed, and (b) shows a state in which the supply port is opened. 
         FIG.  13    is a schematic top view of a feed portion of a coagulation tank of a continuous coagulation machine in a soybean curd production device according to a third modification of the second embodiment of the present invention. 
         FIG.  14    is a schematic side view of a coagulation tank of a continuous coagulation machine in a soybean curd production device according to a fourth modification of the second embodiment of the present invention. 
         FIG.  15    is a schematic top view of a feed portion of the coagulation tank of the continuous coagulation machine showing a process of supplying coagulant-containing soymilk to the continuous coagulation machine by using a switchable three-way valve in the soybean curd production device according to the fourth modification of the second embodiment of the present invention. 
         FIG.  16    illustrates (a) showing a schematic top view showing a soybean curd production device according to a third embodiment of the present invention, (b) showing a schematic side view of (a), and (c) showing an enlarged view of a portion XV in (b). 
         FIG.  17    illustrates (a) showing a view corresponding to the portion XV in (b) of  FIG.  16    in a soybean curd production device according to a modification of the third embodiment of the present invention, and (b) showing a view corresponding to the portion XV in (b) of  FIG.  16    in a soybean curd production device according to another modification of the third embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a soybean curd production device and a soybean curd production method according to embodiments of the present invention will be described in detail with reference to the drawings. 
     First Embodiment 
     As shown in  FIG.  1   , a soybean curd production device  1  according to a first embodiment includes: a boat-shaped continuous coagulation machine  10  that produces a pudding-like soymilk coagulated product by coagulating and aging coagulant-containing soymilk in which soymilk and a coagulant are mixed by a mixer  2 ; and a continuous forming machine  30  that forms the soymilk coagulated product into soybean curd while dehydrating the soymilk coagulated product. 
     The soymilk and the coagulant are fed at predetermined flow rates by metering pumps P 1  and P 2  from a soymilk tank T 1  and a coagulant tank T 2  in which the soymilk and the coagulant are respectively stored, mixed by the mixer  2 , and then supplied to the continuous coagulation machine  10  as the coagulant-containing soymilk. The soymilk and the coagulant may be separately and directly supplied to the continuous coagulation machine  10  and mixed in a coagulation tank  20 . In any case, most of the substance (50% or more of the coagulant-containing soymilk in one compartment) is preferably supplied below a liquid level. 
     In the soybean curd production device  1  according to the present embodiment, the continuous coagulation machine  10  and the continuous forming machine  30  are linearly arranged side by side so that a feed direction of the coagulant-containing soymilk by the continuous coagulation machine  10  is the same as a feed direction of the soymilk coagulated product by the continuous forming machine  30 . Although an installation space is wide, it is possible to transfer the soft and substantially pudding-like coagulated product uniformly without crushing the coagulated product too much. Here, a horizontal direction in which the continuous coagulation machine  10  and the continuous forming machine  30  are arranged is set as an X direction, a width direction of the continuous coagulation machine  10  and the continuous forming machine  30 , which is a horizontal direction orthogonal to the X direction, is set as a Y direction, and an up-down direction of the continuous coagulation machine  10  and the continuous forming machine  30  is set as a Z direction. 
     The boat-shaped continuous coagulation machine  10  mainly includes: an endless conveyor  11  in which a plurality of partition blades  13  are attached to a surface of a conveyor belt (endless chain)  12  at predetermined intervals; a coagulation tank  20  formed of stainless steel and having a recessed shape in a cross-section to allow the partition blades  13  to pass through an inside of the coagulation tank  20 ; and a cover  29  that covers an upper portion of the endless conveyor  11 . 
     In the endless conveyor  11 , the conveyor belt (endless chain)  12  is wound around two rollers  14  and  15  arranged side by side and substantially horizontally in a vicinity of an inlet and a vicinity of an outlet of the coagulation tank  20 , and the conveyor belt (endless chain)  12  and the plurality of partition blades  13  rotate due to rotation of the two rollers  14  and  15 . 
     The conveyor belt (endless chain)  12  of the continuous coagulation machine  10  is a steel belt, or a belt, a chain, or a wire made of rigid metal such as stainless steel or titanium, and is not particularly limited as long as a large number of partition blades can be fixed. 
     The plurality of partition blades  13  each include a plate member  13  made of a metal steel such as stainless steel or titanium, and a member  13   b  made of rubber, and each have a rectangular shape that is long in the width direction and short in a longitudinal direction. The plurality of partition blades  13  are each sized to be inscribed in or be in contact with inner surfaces of a bottom wall  21  and both side walls  22  and  23  of the coagulation tank  20  by the sealing member  13   b  made of rubber such as flexible NBR, EPDM, (fluororubber) such as FKM, or silicon rubber so as to prevent liquids such as the soymilk and “supernatant liquid” from leaking. Therefore, in the continuous coagulation machine  10 , coagulation compartments are each formed by the adjacent partition blades  13  and the coagulation tank  20 . 
     The bottom wall  21  of the coagulation tank  20  is curved in accordance with a trajectory of tip ends of the partition blades  13  in the vicinity of the inlet through which the coagulant-containing soymilk is supplied, and is formed substantially horizontally from an outlet end portion  21   a  to a curved portion toward the vicinity of the inlet. 
     Further, at least one of the side walls  22  and  23  in the vicinity of the inlet of the coagulation tank  20  is provided with a supply port  24  through which the coagulant-containing soymilk is supplied. Therefore, the coagulant-containing soymilk supplied from the supply port  24  is coagulated and aged as the partition blades  13  move toward the vicinity of the outlet of the continuous coagulation machine  10 . An opening and closing member in a second embodiment to be described later may be provided at a supply port. 
     Further, the cover  29  is formed in accordance with the trajectory of the tip ends of the partition blades  13  so as to cover an upper portion of the whole of the plurality of partition blades  13  located at a return portion. As a result, it is possible to prevent secondary contamination due to falling bacteria in air and to improve a heat retaining property in a coagulation and aging process during production. 
     The continuous forming machine  30  includes an upper endless conveyor  31  around which an upper fabric  32  is wound, and a lower endless conveyor  41  around which a lower fabric  42  is wound. A surface of the upper fabric  32  facing downward and a surface of the lower fabric  42  facing upward are substantially horizontal and face each other with a gap. 
     Central axes of rollers of the upper endless conveyor  31  and the lower endless conveyor  41  are arranged parallel to central axes of the two rollers  14  and  15  of the endless conveyor  11 . 
     Further, each of the upper fabric  32  and the lower fabric  42  has flexibility and toughness, and is a resin filter fabric (see, for example, Japanese Patent No. 4004413) in which monofilaments of a fluorine resin, a polyester resin, a polypropylene resin, a polyethylene resin, or the like are woven into a plain weave, a twill weave, or the like. Each of the upper fabric  32  and the lower fabric  42  may be a wire net belt (a glasses link belt conveyor, a flat flex conveyor, a chocolate conveyor, or the like) in which a wire made of metal such as stainless steel is woven in a resin filter fabric belt and that has a flat-wound shape at starting and rear ends and forms a bottom surface and side walls on a conveyance surface, and may be a perforated or non-perforated food resin belt (a Teflon belt or a food belt). 
     The upper endless conveyor  31  and the lower endless conveyor  41  sandwich and press the soymilk coagulated product from upper and lower sides to form the soybean curd while dehydrating the soymilk coagulated product, and convey the soybean curd to a downstream process. 
     Here, the lower endless conveyor  41  overlaps with the coagulation tank  20  when viewed from above such that the lower fabric  42  is located below the outlet end portion  21   a  of the bottom wall  21  of the coagulation tank  20 . That is, the lower endless conveyor  41  is configured to extend closer to a continuous coagulation machine side than the upper endless conveyor  31  so as to be located below and close to the coagulation tank  20 . 
     The coagulation tank  20  and the upper endless conveyor  41  are linearly arranged side by side in the X direction above the lower fabric  42  of the lower endless conveyor  41 . 
     Further, the continuous coagulation machine  10  is driven synchronously with the continuous forming machine  30 . That is, the conveyor belt (endless chain)  12  of the endless conveyor  11  of the continuous coagulation machine  10 , the upper fabric  32  of the upper endless conveyor  31  of the continuous forming machine  30 , and the lower fabric  42  of the lower endless conveyor  41  are continuously driven at the same speed and in the same direction at respective feed portions. 
     As a result, a difference in height between the outlet end portion  21   a  of the bottom wall  21  of the coagulation tank  20  and the lower fabric  42  of the lower endless conveyor  41  is small, and the soymilk coagulated product can be directly transferred onto the lower fabric  42  by an inertial force of the pudding-like soymilk coagulated product conveyed out of the continuous coagulation machine  10  instead of using a dispenser or a feeder. In addition, it is possible to transfer the soymilk coagulated product onto the lower fabric  42  while ensuring uniformity of quantity by the coagulation compartments partitioned by the partition blades  13 . 
     In a two-story structure in which a coagulation machine is disposed above a forming machine as in the related art, a soymilk coagulated product is in a state of being always crushed due to a difference in height, and at an outlet of a coagulation tank, soybean curd flows out at once for each partition section. Therefore, usually, an endless conveyor of the coagulation machine is operated intermittently and the forming machine is also operated intermittently accordingly. When the coagulation machine and the forming machine are continuously operated, the soymilk coagulated product is likely to be added non-uniformly. 
     On the other hand, since the soybean curd production device  1  according to the present embodiment is linear in an one-story ground arrangement, it is possible to prevent the soymilk coagulated product from flowing out at once, and it is possible to directly and softly transfer the soft and pudding-like soymilk coagulated product onto the lower fabric  42  without the difference in height and without crushing the soymilk coagulated product. When maintenance or the like of the soybean curd production device  1  is performed, work at a high place is reduced, and work safety is also improved. 
     For example, in a case of a hard and pudding-like soymilk coagulated product having a breaking force of 60 gf/cm 2  or more, a coagulation machine (Japanese Patent No. 3568193) using a steel belt can be applied, but in a case of a very soft and pudding-like soymilk coagulated product having a breaking force of less than 60 gf/cm 2 , specifically, about 1 gf/cm 2  to 40 gf/cm 2 , particularly about 5 gf/cm 2  to 20 gf/cm 2 , the soymilk coagulated product slips or breaks and cannot be conveyed well. On the other hand, by using the continuous coagulation machine  10  in the present embodiment, even the very soft and pudding-like soymilk coagulated product having a small breaking force can be conveyed and transferred almost without being crushed. 
     Further, the continuous coagulation machine  10  and the continuous forming machine  30  are small in the difference in height and are driven at the same speed and synchronously with each other, and thus the very soft and pudding-like soymilk coagulated product can be uniformly transferred onto the lower fabric  42  of the continuous forming machine  30  without being crushed. 
     As compared with intermittent operation (batch type), the continuous coagulation machine  10  and the continuous forming machine  30  are small in a load exerted on a machine, are also small in a starting current value for a drive motor, and achieve energy saving. Further, as compared with batch driving, an influence of timing deviation caused by elongation or the like of a chain due to long-term use is also small. 
     Further, a width A of the coagulation tank  20  of the continuous coagulation machine  10  is substantially equal to a width B of a press portion (a width of the upper fabric  32  in the Y direction) of the continuous forming machine  30 . Specifically, the width A of the coagulation tank  20  is 80% to 100%, preferably 90% to 100% of the width B of the press portion. In an actual size, the width B of the press portion is 500 mm to 3,000 mm (approximately 1,000 mm to 2,000 mm). 
     In a fried soybean curd forming machine in the related art, a coagulation state is a pasty coagulation state (a coagulation state in which a soymilk coagulated product and yellowish-green “supernatant liquid” are mixed), and a width of a coagulation tank of a boat-shaped coagulation machine is generally narrower than a forming width of a forming machine, and thus the soymilk coagulated product is spread and uniformly dispensed over the width of the forming machine by a dispenser (feeder). 
     On the other hand, in the present embodiment, the width A of the coagulation tank  20  of the continuous coagulation machine  10  is substantially equal to the width B of the press portion of the continuous forming machine  30 , and thus the very soft and substantially pudding-like soymilk coagulated product conveyed out of the coagulation machine  10  can softly land on the lower fabric  42  of the forming machine  30  directly (without using the dispenser or the like) without being crushed when the soymilk coagulated product is transferred between the continuous coagulation machine  10  and the continuous forming machine  30 . 
     Further, the bottom wall  21  of the coagulation tank  20  is formed substantially horizontally from the vicinity of the inlet to the outlet end portion  21   a . Therefore, the difference in height is small, and it is possible to prevent deviation of a little free water (also referred to as the so-called “supernatant liquid”, “separated water”, and “exuding water”), to smoothly convey the free water together with the soft and substantially pudding-like soymilk coagulated product, and to prevent a slide-down phenomenon due to influence of gravity at the time of transferring to the forming machine. 
     &lt;Modification&gt; 
     In the above embodiment, a gap is present between the bottom wall  21  of the coagulation tank  20  and the lower fabric  42 , but as in a first modification shown in  FIG.  2   , the bottom wall  21  including the outlet end portion  21   a  of the coagulation tank  20  may be configured to almost come into contact with the lower fabric  42 . 
     As a result, a difference in height between the outlet end portion  21   a  of the bottom wall  21  of the coagulation tank  20  and the lower fabric  42  of the lower endless conveyor  41  is smaller, and the soybean curd coagulated product can be transferred onto the lower fabric  42  more reliably without being crushed. 
     In the above embodiment, the endless conveyor  11  of the continuous coagulation machine  10  is configured such that the tip ends or attachment ends of the plurality of partition blades  13  move horizontally in the feed direction, but as in a second modification shown in  FIG.  3   , the endless conveyor  11  may be configured such that the tip ends or the attachment ends rise and move in a vicinity of an outlet of the coagulation tank  20 . That is, the conveyor belt (endless chain)  12  of the endless conveyor  11  is inclined upward by an angle θ 0  (in a range of 0°≤θ 0 ≤30°) in a feed direction of the continuous coagulation machine  10  such that the tip ends or the attachment ends of the partition blades  13  gradually rise upward. Specifically, a height t of the roller  14  with respect to the roller  15  is preferably adjusted to be equal to or higher than a height T of the soymilk coagulated product, and the roller  14  and the roller  15  guide the conveyor belt (endless chain)  12  by turning from a feed side to a return side. Therefore, the roller  14  on an outlet side is disposed to be higher than the roller  15  on an inlet side, and after the conveyor belt (endless chain)  12  passes through a guide roller  25 , the conveyor belt  12  rises together with the partition blades  13  and the partition blades  13  are gradually moved away from the lower fabric  42 . 
     When the tip ends of the partition blades  13  move horizontally in the feed direction in the vicinity of the outlet, the partition blades  13  may kick up an upper end of the soymilk coagulated product to somewhat crush the soymilk coagulated product at the time of inverting from the feed portion to the return portion. 
     On the other hand, as in the modification, the partition blades  13  move upward in the vicinity of the outlet, and thus an upper end of the soymilk coagulated product is not kicked up, and the soymilk coagulated product can be reliably prevented from being crushed. Further, during coagulation and aging, separated water accumulated between the adjacent partition blades  13  (each coagulation compartment) can also be removed more quickly. 
     The endless conveyor  11  may be configured such that an inclination of the conveyor belt (endless chain)  12  can be adjusted as needed. 
     In the above embodiment, the supply port  24  through which the coagulant-containing soymilk is supplied is provided in the side wall  22  of the coagulation tank  20  in the vicinity of the inlet of the coagulation tank  20  of the continuous coagulation machine  10 , but as in a third modification shown in  FIG.  4   , the supply port  24  may be provided in the bottom wall  21  of the coagulation tank  20 . 
     In any of cases, it is preferable that the supply port  24  causes the coagulant-containing soymilk to flow in from below a liquid level in order to prevent foaming or bubbling. The liquid level is set assuming a case of soybean curd in which an amount of coagulant-containing soymilk supplied into a coagulation compartment is the smallest. 
     For example, when the soymilk and the coagulant flow in from above the inlet side of the coagulation machine  10 , the supply port  24  is provided at a fixed distance so as not to interfere with the rotating partition blades  13 , and thus foaming occurs or air bubbles are mixed in the coagulated product due to momentum of inflow, and the coagulation is liable to be non-uniform. Further, a space of the coagulation compartment is not stabilized, and non-uniform coagulation is also likely to occur. In particular, in the soymilk containing no defoaming agent, foaming is very likely to occur, and significant air bubbles are mixed. 
     On the other hand, in the above embodiment and the third modification, a shape of the space of the coagulation compartment is fixed (rectangular parallelepiped shape), and when the coagulant-containing soymilk flows in from the supply port  24 , most of the coagulant-containing soymilk flows near the liquid level or in the liquid. Therefore, the homogeneous and pudding-like soymilk coagulated product with less foaming and with less air bubbles mixed is likely to be stably obtained. Since the shape of the coagulation compartment changes at a position where the partition plates turn from the return side to the feed side, when the coagulation compartment is formed which is partitioned by the front and rear partition plates after passing the turning position and is then fixed without change, a coagulation state of having high water retention property can be stably obtained by feeding the coagulant-containing soymilk. 
     The supply port  24  is not limited to being provided at one location of a side wall in the present embodiment and one location of a bottom wall in the third modification, and the supply ports  24  may be appropriately provided, for example, at two locations of both side walls, a plurality of locations on the bottom wall, and three locations of the both side walls and the bottom wall. 
     As in a fourth modification shown in  FIG.  5   , the continuous coagulation machine  10  may further include, on the cover  29 , a cleaning unit  26  that cleans the partition blades  13  located at a return portion, and a vapor supply device  27  that supplies vapor to an inside of the cover  29 . A receiving tray  28  in which a cleaning liquid is received may be provided below the cleaning unit  26  and below the partition blades  13  and the conveyor belt (endless chain)  12  located at the return portion, and in addition to during non-production, the partition blades  13  can be cleaned every time the partition blades  13  rotate one round during production, and sanitary environment can be maintained even during long-term production. 
     At the time of cleaning, the supply port  24  may be used as a discharge port through which the coagulant-containing soymilk or a cleaning chemical liquid is discharged, or the discharge port may be separately provided in the vicinity of the inlet of the coagulation tank  20 . 
     The vapor is supplied to the inside of the cover  29  by the vapor supply device  27 , and thus the soymilk coagulated product can be kept at a predetermined temperature. A space inside the cover  29  is maintained at 60° C. to 100° C. by using saturated vapor together with steam generated from the soymilk coagulated product, and thus it is possible to prevent propagation of various bacteria and to convey the soymilk coagulated product in a sanitary manner. 
     The cleaning unit  26  can perform cleaning in place (CIP) using a chemical liquid, and sterilization using vapor or hot water or a chemical liquid. Since the partition blades  13  rotate in the boat-shaped continuous coagulation machine  10 , a soybean curd residue adhering to the partition blades  13  (parts each formed of stainless steel and a rubber spatula) is unsanitary after a long time elapses. Therefore, the cleaning unit  26  including a high-pressure cleaning nozzle at the return portion of the rotating trajectory of the partition blades  13  is provided to wash away the soybean curd residue during the production. 
     At the time of cleaning after production, immersion cleaning in which the partition blades  13  rotate is also used in combination by deeply storing the cleaning chemical liquid in the coagulation tank  20  (at a level equal to or higher than a level of the soymilk coagulated product at the time of production, and preferably in a fully filled state). Solids in the cleaning chemical liquid discharged at the outlet end portion  21   a  of the coagulation tank  20  are removed with a filter, and the cleaning chemical liquid is then returned to the soymilk tank or a cleaning chemical liquid tank. A waste liquid after rinsing is not returned and is drained. Further, a spray nozzle (a rotary spray nozzle, a spray ball, or the like) capable of spraying a chemical liquid may be provided in the cover  29  to perform CIP on the inside of the cover  29 , the coagulation tank  20 , and the partition blades  13 . 
     Further, the coagulation tank  20  may be provided with a double structure or a heat retaining unit. The coagulation tank  20  is generally made of stainless steel, but heat dissipation is large in one sheet structure, and the quality of the soybean curd in the vicinities of the side walls and the bottom wall becomes soft. The soft soybean curd may cause a trouble with the fabric in the subsequent forming machine  30 . By providing the heat retaining unit such as providing an air layer in a double structure, inserting a heat insulating material, forming a vacuum layer, and circulating and temperature-controlling hot water, water vapor or a heat medium, the aged soybean curd in both the vicinities of the side walls and the vicinity of the bottom wall is not different from the quality of the soybean curd at a central portion, elastic, soft, and pudding-like soybean curd with good sticking as a whole can be produced, and loss is also reduced. An amount of the soybean curd residue adhering to the partition blades  13  can also be reduced. Material saving is also achieved by not using the extra coagulant or cleaning water. 
     In the above embodiment, the partition blades  13  are attached at θ=90° relative to a horizontal conveyor belt at the feed portion, but may be attached to be inclined by a predetermined angle θ as long as the partition blades  13  are configured to be close to or come into contact with the bottom wall  21  and the side walls  22  and  23  of the coagulation tank  20 . 
     Specifically, the partition blades  13  may be attached to the surface of the conveyor belt (endless chain)  12  at an angle in a range of 45°≤θ≤150°, preferably 60°≤θ≤90°. In particular, as in a fifth modification shown in  FIG.  6   , the partition blades  13  may be attached to be inclined by 45°≤θ≤90° or 60°≤θ≤90° such that the tip ends thereof are closer to the inlet than base ends in the feed portion. As a result, an upper portion of the soymilk coagulated product to be kicked up can be reduced in the vicinity of the outlet. 
     In a sixth modification shown in  FIG.  7   , the soymilk and the coagulant are fed at predetermined flow rates by the metering pumps P 1  and P 2  from the soymilk tank T 1  and the coagulant tank T 2 , and the coagulant-containing soymilk in which the soymilk and the coagulant are mixed by the mixer  2  is then supplied to the coagulation tank  20 . Valves V 1  and V 2  are respectively provided between the metering pump P 1  and the mixer  2  and between the metering pump P 2  and the mixer  2 , and circulation paths C 1  and C 2  through which the soymilk and the coagulant are respectively returned to the soymilk tank T 1  and the coagulant tank T 2  are provided. In this case, the coagulant-containing soymilk may be supplied by continuous supply or batch supply. 
     For example, when the continuous supply of the coagulant-containing soymilk is performed, in a state where the switching valves V 1  and V 2  for the soymilk and the coagulant are switched to production sides, the soymilk and the coagulant always flow at the predetermined flow rates and the partition blades  13  in the coagulation tank  20  are continuously driven. In this case, batch driving of the partition blades  13  cannot be performed. 
     On the other hand, when the batch supply of the coagulant-containing soymilk is performed, at the time of the partition blade  13  reaching a predetermined position, the switching valves V 1  and V 2  for the soymilk and the coagulant are switched from circulation sides to the production sides to start supply, to the coagulation tank  20 , of the coagulant-containing soymilk in which the soymilk and the coagulant are mixed by the mixer  2 . When the supply of a predetermined amount is completed, the switching valves V 1  and V 2  are switched to the circulation sides to stop the supply. During this period, the partition blades  13  may be continuously driven, or the partition blades  13  may be driven in batch after the supply is stopped until the next partition blade  13  reaches the predetermined position. Therefore, the partition blades  13  are preferably driven by basic continuous driving, but may be driven by batch driving. 
     When the supply is stopped, it is preferable to perform so-called “filling standby” (see JP-A-11-346696). The filling standby is to, when the soymilk switching valve V 1  and the coagulant switching valve V 2  are switched from the production sides to the circulation sides, perform switching of the valve V 2  more quickly and fill only the soymilk in the valve V 1 , then in the mixer  2 , and then in the supply port  24  to stand by. As a result, the mixer  2  and the front and back of the mixer  2  can be prevented from being clogged with the soymilk coagulated product, and the soybean curd whose coagulation is crushed can be prevented from being mixed to deteriorate the quality. The soymilk component is supplied in a next batch, but no problem in quality arises when the soymilk component is mixed with the coagulant-containing soymilk. Creating a portion where the coagulant is not added in the last short time in this way and delaying a timing of the valve V 1  are referred to as the “filling standby”. 
     As in a seventh modification shown in (a) of  FIG.  8    and (b) of  FIG.  8   , in the endless conveyor  11 , a pair of endless chains  71  and  71  that connect the conveyor belt  12  on both sides in the width direction are wound around sprockets  70  and  70 . The sprockets  70  and  70  rotate a drive shaft  75  by a drive unit  74 , and thus the conveyor belt  12  is driven together with the endless chains  71  and  71 . The conveyor belt  12  is implemented by a plurality of metal plates connected to the endless chains  71  and  71 , and the partition blades  13  are attached to surfaces of the metal plates. 
     Each of the metal plates may have not only a flat plate shape but also an angle shape or a round bar shape, and an H-shaped steel, a C-shaped steel, or the like may be applied. A material of the metal plate is not limited to stainless steel, and may be titanium, aluminum, or a hard resin. The endless conveyor  11  may be configured such that the conveyor belt  12  is not provided and the partition blades  13  are directly attached to the endless chains  71 . Further, a driven sprocket is disposed at a position (not shown) of the roller  15  in  FIG.  1   . 
     In an example in (a) of  FIG.  8   , the endless chains  71  and  71  and the sprockets  70  and  70  are disposed on insides, in the width direction, of the side walls  22  and  23  of the coagulation tank  20 , whereas in an example in (b) of  FIG.  8   , the endless chains  71  and  71  and the sprockets  70  and  70  are disposed on outsides, in the width direction, of the side walls  22  and  23  of the coagulation tank  20 . 
     When the endless chains  71 ,  71  and the sprockets  70 ,  70  are disposed as shown in (a) of  FIG.  8   , the continuous coagulation machine  10  can be designed to be compact in the width direction, and at the time of cleaning, the conveyor belt  12 , the endless chains  71 ,  71 , and the sprockets  70 ,  70  can be cleaned together with the partition blades  13 . 
     When the endless chains  71 ,  71  and the sprockets  70 ,  70  are disposed as shown in (b) of  FIG.  8   , even if dirt such as a grease residue, an oil residue, or the soybean curd residue adhering to the chains is generated or metal powder such as rust is generated on these metal parts due to electrolytic corrosion or wear in long-term use, it is possible to prevent the dirt and the metal powder from dropping into the coagulation tank  20 , a safe and sanitary embodiment with improved foreign matter entering prevention effect can be obtained, and sanitation management based on hazard analysis critical control point (HACCP: made obligatory in Japan from June 2021) can also be implemented. Further, collection tanks  72  and  72  that can separately collect the metal powder and foreign matter are provided on the outsides, in the width direction, of the side walls  22  and  23  of the coagulation tank  20 , and below the endless chains  71  and  71 . Therefore, during cleaning, a waste liquid containing the metal powder and a collection liquid on a product side can be distinguished from each other, and the dirt and the metal powder can be prevented from flowing into a chemical liquid pipe and a chemical liquid tank side (a pipe and a tank through which the collection liquid on the product side flows). 
     The endless chains  71  and  71  are not particularly limited, but it is preferable to use a chain in which foreign matter is unlikely to be generated, such as a super long life oil-free stainless steel chain. An example of the endless chains  71  and  71  includes a SUS-RB super long life stainless steel chain which is made of an RB ceramic (porous carbon material) composite material and SUS304, and even when the stainless steel chain is used in an oil-free state, wear elongation can be significantly reduced. Other examples of the endless chains  71  and  71  include a bearing roller conveyor chain having oil-free and water-resistant specifications, an environment-resistant conveyor chain, and a stainless steel conveyor chain having excellent corrosion resistance, chemical resistance, heat resistance, and cold resistance. 
     Further, the endless conveyor  11  may be configured to include three sets of endless chains and sprockets by connecting the endless chains to a central portion of the conveyor belt  12  in the width direction. 
     Second Embodiment 
     Next, a soybean curd production device according to a second embodiment of the present invention will be described with reference to  FIGS.  9  and  10   . 
     In the first embodiment described above, the continuous coagulation machine is configured to include, in the vicinity of the inlet of the coagulation tank  20 , the supply port  24  through which the coagulant-containing soymilk is supplied from the side wall  22  of the coagulation tank  20 , whereas in the second embodiment, the coagulation tank  20  is configured to include the opening and closing member that opens and closes the supply port  24  to prevent liquid leakage or backflow from the supply port  24 . 
     Specifically, as shown in  FIG.  10    in an enlarged manner, a shutter-type lid  50  that can be opened and closed by a cylinder  53  is provided on the side wall  22  including the supply port  24 . 
     In this case, while the partition blade  13  is passing through the supply port  24 , the shutter-type lid  50  is closed. While the partition blade  13  does not pass through the supply port  24 , the rear partition blade  13  reaches a lowermost end, and the shutter-type lid  50  is then opened from a state where a sealing property is reliably ensured so that the soymilk coagulated product does not leak between the sealing member  13   b  and the inner surfaces of the side walls  22  and  23  and the bottom wall  21 . Then, the coagulant-containing soymilk flows almost under the liquid level into the coagulation compartment of the coagulation tank  20  while measuring the coagulant-containing soymilk for a predetermined time, and the shutter-type lid  50  is closed after the predetermined measurement is completed. That is, the partition blade  13  may be driven by continuous driving or batch driving, but the coagulant-containing soymilk is supplied by batch supply. Further, the shutter-type lid  50  may be opened to supply the coagulant-containing soymilk at least until the partition blade  13  overlaps with the supply port  24  again. 
     When a space portion is present in the supply port  24 , a semi-mature or uncoagulated coagulant-containing soymilk coagulated product leaks backward before and after the partition blade  13  rotating continuously overlaps with the supply port  24 . Therefore, as in a first modification shown in  FIG.  11   , it is preferable to use a shutter-type lid  51  that can be opened and closed up and down and in which no step is present between the inner surface of the side wall  22  and a lid surface in a closed state. Further, as in a second modification shown in  FIG.  12   , a commercially available sanitary tank valve (tank bottom valve)  52  may be used such that a tip end portion of the valve  52  closes the inner surface of the side wall  22  without a step in a closed state. That is, any opening and closing member may be used as long as the opening and closing member is a member that temporarily fills a recess (space portion) formed in the side wall of the coagulation tank  20  where the supply port  24  is opened, and flatly closes the supply port  24 . 
     In both the first and second modifications, the coagulant-containing soymilk is intermittently supplied (batch supply) as the opening and closing member (shutter-type lid  51  and tank valve  52 ) is opened and closed at a timing when the partition blade  13  and the supply port  24  overlap with each other. 
     However, when the opening and closing member is not provided in the supply port  24  as in the above embodiment, it is preferable to provide the supply port  24  at a level equal to or higher than the liquid level of the coagulant-containing soymilk supplied to the coagulation compartment, and in this case, the coagulant-containing soymilk may be continuously supplied. 
     Even when the supply port  24  is below the liquid level and some leakage occurs from the recess of the supply port  24 , if the liquid level is not so high and a moving speed of the partition blade  13  is not so slow (the moving speed may be instantaneously increased at the time of passing through the supply port  24 .), a leakage amount is small and does not cause a problem. Thus, in this case, the opening and closing member itself may not be provided. 
     Further, a scraper (opening and closing member) made of rubber, which is the partition blade, may be made longer and sufficiently bent such that the scraper comes into contact with an inner surface of the coagulation tank  20  and a surface of the scraper closes the supply port  24 . 
     Specifically, in a third modification shown in  FIG.  13   , when the supply ports  24  are formed in the both side walls  22  and  23  of the coagulation tank  20 , scrapers  13   a  made of rubber are formed to be longer in the width direction so as to temporarily close the supply ports  24  of the side walls  22  and  23 . The scraper  13   a  made of rubber can also be applied when the supply port  24  is provided only in one side wall. In a fourth modification shown in  FIG.  14   , when the supply port  24  is formed in the bottom wall  21  of the coagulation tank  20 , a scraper  13   b  made of rubber is formed to be longer in the up-down direction to temporarily close the supply port  24  of the bottom wall  21 . 
     In both cases of the third and fourth modifications described above, the coagulant-containing soymilk may be continuously supplied. 
     In a fifth modification shown in  FIG.  15   , supply ports  24   a  and  24   b  are provided in two proximity locations of one side wall  22  of the coagulation tank  20 , and the coagulant-containing soymilk is continuously supplied to the continuous coagulation machine by switching the supply port using a three-way valve  56 . 
     At a position where the partition blade  13  and the supply port  24   b  slightly overlap, a supply direction is changed by the three-way valve  56 , supply from the supply port  24   b  is not performed, and supply from the supply port  24   a  is continued. In this case, the coagulant-containing soymilk is continuously supplied, and the partition blade  13  is also continuously driven. Therefore, unlike a batch type coagulation machine, temporary stop of the supply and filling standby are not required, the non-uniform coagulation is reduced, and the coagulation quality becomes more uniform. A horizontal distance a between centers of two nozzles  57  is preferably a size satisfying relationships of b&gt;2c, b&gt;a, a=b/2, and c≤a≤b−c when a pitch of the partition blades  13  is set as b and a horizontal width of an opening of the supply port  24  is set as c. 
     While the coagulant-containing soymilk is continuously supplied from the mixer  2 , the coagulant-containing soymilk is alternately supplied to the supply ports  24   a  and  24   b  in the two locations of the coagulation tank  20 . Although not shown, each supply port is provided with the opening and closing member such as a tank valve. 
     First, the coagulant-containing soymilk is supplied to a compartment A through a flow path on a right side, while a flow path on a left side is closed because the flow path on the left side overlaps with the partition blade  13 . 
     Next, when the partition blade  13  advances toward the left side and overlaps with the supply port  24   a  on the right side, the three-way valve  56  is switched, the coagulant-containing soymilk is subsequently supplied to the compartment A through the flow path on the left side, and the supply of a predetermined amount is completed. 
     When the partition blade  13  further advances toward the left side and overlaps with the supply port  24   b  on the left side, the three-way valve  56  is switched, and the coagulant-containing soymilk is supplied to a compartment B through the flow path on the right side. 
     Thereafter, the coagulant-containing soymilk is continuously supplied by repeating this process. Therefore, unlike the batch type coagulation, the filling standby is not required, the non-uniform coagulation is reduced, and the coagulation quality becomes more uniform. 
     When the supply ports  24  are provided in three or more locations of the side wall  22  of the coagulation tank  20 , switching valves may be provided according to the number of supply ports  24 . 
     Third Embodiment 
     Next, in a third embodiment, as shown in  FIG.  16   , a crushing device  60  is provided between the coagulation tank  20  and the upper endless conveyor  31  and above the lower fabric  42  of the lower endless conveyor  41 . 
     Further, a protective plate  61  with which the crushing device  60  is able to come into contact is provided at a position below the protective plate  60 . Therefore, the lower fabric  42  of the lower endless conveyor  41  is pushed downward and guided by using guide rollers  62  and  63  or the like, so as to avoid the protective plate  61 . 
     As a result, a bottom of the soymilk coagulated product can be firmly crushed on an upper surface of the protective plate  61 , water separation from the lower fabric  42  is promoted, and the soybean curd is well drained. Further, it is possible to obtain the soybean curd that is hard and has uniform hardness. Therefore, it is possible to solve a problem that since the soybean curd is crushed at a height of 5 mm to 10 mm above the lower fabric  42  in order to protect the lower fabric  42  in the related art, a bottom surface is hardly crushed and “two-layer soybean curd” is obtained. 
     The upper surface of the protective plate  61  is disposed so as to be flush with portions of the lower fabric  42  on an upstream side and a downstream side with respect to the position below the crushing device  60 , and the soymilk coagulated product can be smoothly conveyed. 
     As shown in (a) of  FIG.  17    and (b) of  FIG.  17   , the protective plate  61  with which the crushing device  60  is able to come into contact may also serve as the guide roll  63 , and specifically, protective plates  61   a  and  61   b  each have a thickness such that the lower fabric  42  is not damaged, and are each chamfered with rounded corners. The protective plate  61   a  in (a) of  FIG.  17    has an elliptical shape in which both surfaces on an upper surface side and a lower surface side are curved, and the protective plate  61   b  in (b) of  FIG.  17    has a flat upper surface side and a curved lower surface side. The protective plate  61  may be made of rigid metal such as stainless steel, may be made of a resin, or formed of a material made of rubber and having elasticity. 
     Therefore, according to the present invention, silken soybean curd, soft soybean curd, firm soybean curd, fried soybean curd, thick-fried and thin-fried soybean curd, hard soybean curd, tofu pudding, or the like can be produced by using the above soybean curd production device. 
     Specifically, the silken soybean curd or the tofu pudding can be obtained without pressing the soft and pudding-like soymilk coagulated product. The soft soybean curd can be obtained by lightly pressing the pudding-like soymilk coagulated product and creating only grains. Further, the pudding-like soymilk coagulated product is appropriately crushed to a desired degree by the crushing device  60  and then pressed, and thus the firm soybean curd, the thick-fried and thin-fried soybean curd, the hard soybean curd, or the tofu pudding is produced. The fried soybean curd, the hard soybean curd and Okinawa style tofu are generally produced from a pasty coagulated product, but can also be produced by finely crushing the pudding-like coagulated product obtained from thin soymilk. As a result, the soybean curd that has water retention property and does not easily lose a taste thereof is obtained, a storage period becomes long by boiling sterilization or the like, and a delicious state is easily maintained. 
     In each soybean curd production device  1  described above, the continuous coagulation machine  10  coagulates and ages, with the coagulant, the soymilk of 50° C. to 95° C. (preferably 60° C. to 85° C.) having a solid content of 3 wt % to 20 wt %, preferably 5 wt % to 15 wt %, thereby producing the pudding-like soymilk coagulated product. 
     After coagulation and aging, a so-called “pasty” coagulation state in which the “supernatant liquid” and the coagulated product are separated may be obtained, and the present invention can be expected to have a great effect in a coagulation state having a pudding-shape or a silken soybean curd shape and having high water retention property. 
     Soft and high-quality firm soybean curd (tofu pudding shape) having high water retention property can be formed by placing the soft and pudding-like soymilk coagulated product on the lower fabric of the forming machine without crushing the soymilk coagulated product too much, and appropriately crushing the soymilk coagulated product with the crushing device  60 . As a result, the method is sanitary, labor-saving, has high production efficiency, and enables mass production. 
     As the coagulant, a slow-acting coagulant and an emulsified bittern can be suitably used, and after mixing with soymilk, the slow-acting coagulant requires a time of 5 seconds to 180 seconds, preferably 10 seconds to 120 seconds until coagulation is started. For example, any commercially available slow-acting coagulant may be used, and in addition to an emulsified bittern in which magnesium chloride is wrapped in oil or an emulsifier, slow-acting coagulants such as GDL (glucono delta lactone), gypsum powder (calcium sulfate, coarse particle), salt, and transglutaminase can be used. A gelling auxiliary material (thickening polysaccharide) such as agar, carrageenan, curdlan, or starch may be contained. Further, a production method in which these components are appropriately blended may be used. When the emulsified bittern is used as the coagulant, sweetness can also be increased. In order to assist the slow-acting, a pH adjusting agent (sodium bicarbonate or the like) that adjusts the soymilk to alkalinity, a polyphosphate-based additive having a chelating action, or the like may be used in combination. 
     Although the embodiments are described above with reference to the drawings, it is needless to say that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications may be conceived within the scope of the claims. It is also understood that the various changes and modifications belong to the technical scope of the present invention. Components in the embodiments described above may be combined freely within a range not departing from the spirit of the present invention. 
     The present application is based on Japanese Patent Application No. 2020-119817 filed on Jul. 13, 2020, the contents of which are incorporated herein by reference. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1 : soybean curd production device 
               10 : continuous coagulation machine 
               11 : endless conveyor 
               12 : conveyor belt (endless chain) 
               13 : partition blade 
               20 : coagulation tank 
               24 : supply port 
               30 : continuous forming machine 
               31 : upper endless conveyor 
               32 : upper fabric 
               41 : lower endless conveyor 
               42 : lower fabric 
               50 ,  51 : shutter-type lid (opening and closing member) 
               52 : tank valve (opening and closing member)