JP2016151382A - Ice slurry refrigeration machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ice slurry refrigeration machine capable of facilitating uniform overcooling of frozen objects such as foods.SOLUTION: An ice slurry refrigeration machine includes: a freezing tank 101 housing antifreezing fluid 102; temperature control devices 107, 108 configured to control a temperature of the antifreezing fluid 102 to -20 to -3°C; circulation means 112 configured to circulate the antifreezing fluid 102 containing ices housed in the freezing tank 101; and a controller 107 configured to stop operation of the circulation means 112 in a state where a frozen object 115 is immersed into the antifreezing fluid 102.SELECTED DRAWING: Figure 1

Description

  The present invention relates to cryopreservation of organic substances such as food.

  In Patent Document 1, a method of freezing food by immersing it in a fluid (hereinafter referred to as “ice slurry”) in which ice is generated in an antifreeze liquid whose temperature is controlled in a temperature range of −20 ° C. to −50 ° C. Is disclosed.

JP 2011-017512 A

  However, in the method of freezing by simply immersing in ice slurry at a temperature lower than −20 ° C., scraping means and ice slurry are compared with the freezing method (hereinafter referred to as “brine freezing”) in which the ice is immersed in antifreeze and frozen. More cost is required for the circulation means. Furthermore, since convection is hindered by the ice in the form of slurry, the cooling rate is slower than that of a brine refrigerator at the same temperature, and it is difficult to improve the refrigeration quality in the normal refrigeration method compared to the brine refrigeration method. In addition, in an ice slurry, when food is put into a lattice-shaped jar and frozen, and when the food is taken out, the jar is pulled out and the food is taken out, so a lot of ice enters the jar and becomes heavy. Moreover, when food was put into a freezing tank without putting it in a basket, the ice could interfere and the inside could not be seen, and it was difficult to take out the food.

  Then, this invention makes it a subject to provide the ice slurry refrigerator which can aim at facilitation of the uniform supercooling of to-be-frozen objects, such as a foodstuff.

  The inventor obtained the following two findings. The first finding is that if an ice slurry having a temperature range of −3 to −20 [° C.] is used for cooling if the food is relatively thin, it is more easily supercooled to the inside. On the other hand, for a relatively thick food, a temperature range near -5 to -15 [° C] is desirable. When ice slurry having a temperature higher than −3 [° C.] is used, the cooling efficiency is low because it takes a long time to freeze or partially freeze the food. On the other hand, when an ice slurry having a temperature lower than −20 [° C.] is used, it is difficult for the relatively thick food to be uniformly supercooled to the inside, and only the surface is partially frozen even after the supercooling is released. . The second knowledge is that, in order to supercool food (non-frozen), the food can be uniformly supercooled if there is no flow of fluid around the food (freeze). It is.

  The ice slurry refrigerator of the first aspect of the present invention made on the basis of the above knowledge is a freezing tank that contains antifreeze, a temperature control device that controls the temperature of the antifreeze to −20 to −3 [° C.], and A circulation unit that circulates the fluid that has generated ice in the antifreeze contained in the freezing tank; and a controller that stops the operation of the circulation unit in a state where an object to be frozen is immersed in the antifreeze. It is characterized by that.

  By the way, in the case of an ice slurry in which ice is generated in an antifreeze liquid that is lighter than water such as an ethanol aqueous solution, the ice sinks to the bottom and a lump of ice is formed at the bottom. Therefore, the ice slurry accommodated therein must be stirred from the bottom of the freezing tank, and the stirring work is difficult. Furthermore, when a lighting fixture or a temperature sensor is provided on the bottom surface, the fixture or sensor may be damaged during stirring.

  Therefore, the ice slurry refrigerator of the first aspect of the present invention may further include cooling means provided at a location different from the bottom of the freezing tank.

  The ice slurry refrigerator of the first aspect of the present invention may further include an illuminating unit provided at the bottom of the freezing tank and irradiating light upward.

  The ice slurry refrigerator according to the second aspect of the present invention is provided in a freezing tank for storing the antifreezing liquid, a temperature control device for controlling the temperature of the antifreezing liquid to −20 to −3 [° C.], and the bottom of the freezing tank. And illumination means for irradiating light upward.

  Even if it is illuminated from the top surface of the ice slurry, the slurry-like ice reflects the light and you can not see the inside, you do not know the position of the food, but by providing illumination means at the bottom of the freezing tank, illuminating the light upward, The position becomes visible through the liquid level through the shadow of the food. Therefore, it can be frozen without using a bag, and a large load for lifting the bag can be avoided.

  According to the present invention, the flow of fluid around the food is suppressed, and the temperature is controlled to a temperature range of −3 [° C.] to −20 [° C.] in which partial freezing or supercooling is likely to occur at a relatively high temperature The object to be frozen such as food is cooled in the slurry (a fluid in which ice is generated in the antifreeze liquid). As a result, the object to be frozen is uniformly supercooled, and the object to be frozen is frozen after the supercooled state is released, so that damage due to cracking is suppressed and the quality of the frozen object is improved. Moreover, the position of the food immersed in the ice slurry can be specified by a shadow by irradiating the ice slurry upward from the bottom of the freezing tank by the illumination means. For this reason, the object to be frozen can be frozen without using a basket, and a large load for lifting the basket can be avoided.

The structure explanatory view of the refrigerator as a 1st embodiment of the present invention. Explanatory drawing regarding the operation | movement form of the refrigerator of this invention. Structure explanatory drawing of the refrigerator as 2nd Embodiment of this invention.

(First embodiment)
A refrigerator as a first embodiment of the present invention shown in FIG. 1 includes a freezing tank 101, an ice slurry storage tank 111 communicating with the freezing tank 101 through a pair of upper and lower openings, and a control device 107. I have.

  Inside the freezing tank 101 is provided a net 113 for dividing the freezing tank 101 into upper and lower parts. At the bottom of the freezing tank 101 below the net 113, a lighting device 114 (LED) that emits light upward and a signal corresponding to the temperature of the antifreeze liquid 102 (or ice slurry) accommodated in the freezing tank 101 are sent. An output first temperature sensor 116 is arranged. The freezing tank 101 is provided with a lid 103 that opens and closes the upper side, and a lid switch 104 for detecting the open / closed state of the lid 103 is provided at the upper end of the freezing tank 101. In a state where the lid 103 is vacant, an object to be frozen 115 (food, etc.) is taken in and out of the antifreeze liquid 102. The lid 103 is movably connected to the upper end of the freezing tank 101 by a hinge.

  Inside the ice slurry storage tank 111, an evaporator 108 (and an icing plate) and a scraper 109 are arranged. The scraper 109 includes a shaft that is driven to rotate around its axis by the motor 110 and a plurality of wings attached to the shaft, and the ice attached to the evaporator 108 by the wings as the shaft rotates. Is scraped off. A second temperature sensor 105 that outputs a signal corresponding to the temperature of the antifreeze liquid (ice slurry) is disposed above the ice slurry storage tank 111.

  In the ice slurry storage tank 111, circulation means 112 including an impeller is provided in each of a pair of upper and lower openings communicating with the freezing tank 101. A circulation switch 106 for controlling the start and stop of the circulation means 112 is provided. The circulation switch 106 may be a manual type. The start and stop of the circulation means 112 may be automatically switched according to whether the lid switch 104 detects whether the lid 103 is open or closed. In this case, the circulation switch 106 may be omitted. By the operation of the circulation means 112, the ice slurry 102 flows out from the ice slurry storage tank 111 to the freezing tank 101 through the upper opening, and the ice slurry 102 from the freezing tank 101 to the lower side of the ice slurry storage tank 111. It flows in through the opening (see FIG. 1 / black arrow).

  The control device 107 and the evaporator 108 whose operation is controlled thereby constitute a temperature control device that controls the temperature of the antifreeze liquid to −20 to −3 [° C.].

  According to the ice slurry refrigerator configured as described above, the operation of the circulating means 112, the evaporator 108, the scraper 109, and the lighting device 114 is controlled by the control device 107, for example, according to FIG.

(Second Embodiment)
A refrigerator as a second embodiment of the present invention shown in FIG. 3 includes a freezing tank 303, a brine tank 301 in which a brine 302 is accommodated so as to surround a side surface of the freezing tank 303, a control device 308, It has.

  A net 312 that divides the freezing tank 303 into upper and lower parts is provided inside the freezing tank 303. An illuminating device 313 (LED) that emits light upward is disposed at the bottom of the freezing tank 303 below the net 312. A first temperature sensor 315 that outputs a signal corresponding to the temperature of the antifreeze liquid 304 (or ice slurry) accommodated in the freezing tank 303 is disposed above the net 312 in the freezing tank 303.

  Inside the brine tank 301 is provided a net 311 for dividing the brine tank 301 into an inside and an outside. Inside the brine tank 301, an evaporator 309 and a circulation means 310 including an impeller are provided outside the net 311. A circulation switch 307 for controlling the start and stop of the circulation means 310 is provided. The circulation switch 307 may be a manual type. The start and stop of the operation of the circulation means 310 may be automatically switched in response to the detection of the open state and the closed state of the lid 305 by the lid switch 306. In this case, the circulation switch 307 may be omitted. By the operation of the circulation means 310, the brine 302 accommodated in the brine tank 301 is circulated or agitated in such a manner as to go in and out of the net 311. The antifreeze liquid 304 stored in the freezing tank 303 is not stirred or circulated by the circulation means 310. That is, the article to be frozen 314 is cooled by the non-stirred antifreeze liquid 304.

  The brine tank 301 is provided with a lid 305 that opens and closes the upper side thereof, and a lid switch 306 for detecting the open / closed state of the lid 305 is provided at the top of the brine tank 301. In a state where the lid 305 is empty, an object to be frozen 314 (food, etc.) is put in and out of the antifreeze liquid 304. The lid 305 is movably connected to the upper end of the brine tank 301 by a hinge.

[Experiment]
An agar having a concentration of 1.5% is formed into a width of 10 [cm], a depth of 5 [cm], and a thickness of 2 [cm], and the ice slurry refrigerator (see FIG. 1) as the first embodiment of the present invention is used. After freezing in part, it was placed in a freezer at -80 [° C.] for 1 hour to complete freezing, and then naturally thawed at room temperature of 20 [° C.] to measure the drip. The temperature of the ice slurry (antifreeze liquid 102) was compared with the drip rate of the agar frozen while the circulating means 112 was operating or stopped. Table 1 summarizes the temperature of the ice slurry (fluid) in which ice was generated, whether or not the antifreeze liquid 102 was circulated by the circulation means 112, the drip rate, and the time required for partial freezing.

Drip rate (%) = (Agar weight before freezing−Agar weight after thawing) ÷ Agar weight before freezing × 100

  From Table 1, the drip rate is preferably -3 ° C to -20 ° C. In addition, in the presence or absence of circulation of the ice slurry, it is desirable that the ice slurry is frozen by stopping the circulation because of less drip. Moreover, it turns out that it takes time for freezing when the temperature of ice slurry is higher than -3 degreeC. Considering the time and the drip rate, −5 ° C. to −15 ° C. is desirable, and the most desirable is around −7 to −10 ° C. Further, the control of the lighting device 114 and the circulation means 112 according to the form shown in FIG. 2 stops the circulation during the freezing of the food, and enables high-quality freezing. Even if the food 115 is directly input, the presence or position of the food 115 can be known.

  In the ice slurry refrigerator as the second embodiment of the present invention, when the freezing tank 303 and the brine tank 301 are configured so that brine (for example, salt water) also enters the lower part of the freezing tank 303, the inside of the freezing tank 303 The generation time of the ice slurry 304 is shortened. On the other hand, the ice slurry 304 (fresh water ice) that can be made into an ethanol aqueous solution (antifreeze solution 304) has a specific gravity slightly larger than that of the surrounding ethanol aqueous solution, so that ice blocks are formed on the bottom surface of the freezing tank 303. It takes time and effort to scrape off the ice block adhering to the bottom surface of the freezing tank 303. From the viewpoint of securing the installation space for the lighting device 313 and the temperature sensor 315, it may not be preferable to install a scraper (see FIG. 1/109) for scraping off the ice blocks. Therefore, as shown in FIG. 3, by not allowing the brine 302 to absorb heat from the bottom surface of the freezing tank 303, it is possible to make the ice on the inner surface of the upper portion of the side wall of the freezing tank 303, thereby facilitating scraping of the ice. .

101, 303 ... Freezing tank, 102, 304 ... Ice slurry (antifreeze), 103, 305 ... Lid, 104, 306 ... Lid switch, 105, 116, 315 ... Temperature sensor, 106, 307 ... Circulation switch, 107, 308 ... Driver 108, evaporator and icing plate, 109 ice writer, 110 motor, 111 ice slurry reservoir, 112, 310 circulating means 113, 311 312 net, 114, 313 LED lighting fixture 115, 314 Food, 301 Brine tank, 302 Liquid level, 309 Evaporator

Claims (4)

A freezing tank containing antifreeze,
A temperature control device for controlling the temperature of the antifreeze to −20 to −3 [° C.];
A circulating means for circulating a fluid that has generated ice in the antifreeze contained in the freezing tank;
An ice slurry refrigerator, comprising: a control device that stops the operation of the circulating means in a state where an object to be frozen is immersed in the antifreeze liquid.   2. The ice slurry refrigerator according to claim 1, further comprising a cooling means provided at a location different from the bottom of the freezing tank.   The ice slurry refrigerator according to claim 1 or 2, further comprising an illuminating means provided at the bottom of the freezing tank for irradiating light upward. A freezing tank containing antifreeze,
A temperature control device for controlling the temperature of the antifreeze to −20 to −3 [° C.];
An ice slurry refrigerator comprising: an illuminating unit that is provided at a bottom of the freezing tank and irradiates light upward.