RU2655316C1 - Method of the ice plate freezing - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to the field of the final shape ice objects completion, i.e., a plate, a bar, a cube, etc. Ice plates freezing method is implemented by freezing water in a layer of oval-spherical granules, which voids are filled with ice balls of the appropriate size both between the granules and the walls of the mold.

EFFECT: reduction of the layer from oval-spherical granules freezing time in ice objects of finite form.

1 cl, 13 dwg

Description

The method relates to the field of creating artificial ice objects, in particular ice plates, with application in various industries (food, chemical, construction, etc.), but can mainly be used in the production and accumulation of large ice reserves for the summer period.

A known method of freezing a layer of water poured over the surface of an ice or platform at sub-zero air temperatures. Exposure to freezing temperatures, especially at night, leads to freezing of the ice layer. The method is applicable at atmospheric temperature minus (5-15) ° C and below.

The disadvantage of this method is the long time it takes to freeze a layer of water, especially at a small negative air temperature (from 0 ° C to -15 ° C). A 50 mm thick water layer requires many hours of exposure to freeze in ice in the indicated temperature range.

There is a method of freezing ice coatings by backfilling on a substrate (ice of a reservoir, river, lake, surface of the site) a layer of oval-spherical ice granules. Watering the layer with trickles of water creates a rigid framework from this layer by forming ice bridges between the granules. After holding for 1-3 s, the intergranular space of the layer is poured in one-way water and frozen in the cold to achieve strength sufficient to maintain the weight of the pedestrian (patent No. 2556908 for the invention dated 08.08.2013, “Method for freezing ice coatings” / Poltavtsev V.I. ., Miroshnikov P.V., Khrapov A.A.).

The method shows a cubic filling of granules, the layer of which contains 68.1% of ice. But with the most dense laying of granules (Fig. 1), the volume of voids is more than a quarter of the total volume of the layer, because granules of the same size with the most dense packaging occupy 74.04% of the layer volume (http://dssp.petrsu.ru/p/tutorial/ftt/Part1_/part_1_5.htm, as well as IN THE WORLD OF SCIENCE. Scientific American / Edition in Russian No. 3. March 1984. S. 72-82. Packing of balls N. Dzh. A. SLOEN).

And despite the fact that the layer of oval-spherical granules of ice flooded with water freezes faster than the layer of water of the same height (graph 2, point “a” in Fig. 2, freezing kinetics of ice blocks from spherical granules (1 - at -37 ° C; 2 - at -24 ° C; 3 - at -12 ° C) and water (4 - at -37 ° C; 5 - at -24 ° C); solid graphs - experiment, dotted calculation), passes 2 , 71 hours, i.e. significant time for the final freezing of the layer of granules with water, which is the disadvantage of this method. For comparison, a layer of water of the same height (graph 5, point “b”) freezes during this time at the same temperature by only 12%.

At the same time, another drawback of the method is manifested: the larger the size of the granules and the faster the formation of the layer, the slower this layer freezes due to a drop in the rate of freezing of large volumes of water in the spaces between the granules.

The objective of the invention is to reduce the time of freezing a layer of oval-spherical granules, compared with the prototype, for ice objects of the final shape (plate, as well as timber, cube, etc.).

The problem is solved due to the fact that they fill the layer of oval-spherical ice granules into a box-shaped form, irrigate with water with a temperature of 0 ... 0.5 ° C to stabilize the frame, and subsequently fill it with water with a temperature of 0.1-5 ° C and the rate of level rise is less than 0.4 m / s, despite the fact that the voids of the layer both between the granules and the walls of the mold are filled with ice balls of the appropriate size, the layer is irrigated with water in an amount of 2 ... 6 dm ³ per 1 cm of layer height with an area of 1 m ² , and the fill is made from one or more sides of the form.

The dimensions and number of balls for the plate are given in tables 1 and 2.

The essence of the application is reflected in the drawings, where

in FIG. 1 - dense 4-layer stacking of a monofraction of ice granules for plate freezing;

in FIG. 2 - freezing kinetics of a block of ice granules with water;

in FIG. 3 is a view A of the first layer in FIG. one;

in FIG. 4 is a section BB in FIG. 3; an example of the location of ice balls between the walls and the block of granules and inside the stack;

in FIG. 5 - spheres inscribed in the cavities of the tetrahedron and octahedron;

in FIG. 6 - view: laying balls under the 1st layer of granules;

in FIG. 7 - laying balls 6 in the end of the tank;

in FIG. 8 - laying balls between the 1st and 2nd layers of granules;

in FIG. 9 is a view of stacking balls in tetra- and octo-cells between layers;

in FIG. 10 - the size of the balls 4 between the bottom and granules of the 1st layer;

in FIG. 11 - sieving and harvesting fractions of ice balls;

in FIG. 12 - bookmarks of ice balls in the cavity between the granules;

in FIG. 13 - the location of the ice balls in the voids of the 1st layer of granules.

The essence of the proposed method is as follows.

A box-shaped container 1 is made (Fig. 1, end view), and filled with layers of oval-spherical ice granules 2 (hereinafter referred to as granules) packed in tight hexagonal packaging.

To maximize the filling of the container in the first lower layer, take the odd ones: the number of rows (in this case 5) and the number of oval-spherical granules in the extreme rows on the right and left (in this case also 5), the size of which is the same (Fig. 3 ), determines the final dimensions of the container: the number of granules in the extreme rows is the length, and the number of rows is the width of the container. The shape of the container is box-shaped and corresponds to the shape of the frozen elements (plate, bar, cube).

Between the layer of granules and the bottom, as well as the side and end walls (Fig. 3), balls of appropriate sizes are laid (here and hereinafter - balls):

3 - balls between 2 granules, a bottom and a side wall;

4 - between 3 granules and the bottom;

5 - in the corners of the tank (between the pellet, bottom, side and end walls);

6 - between 2 granules, a bottom and an end wall.

The space to the left and to the right of the laying of granules (side cavities, Fig. 4) is filled with balls with a gradual increase in size:

7 - lie on two granules of the lower layer, touch the granules of the upper and side walls;

8 - lie on the granules of the lower layer and touch two granules of the upper and side walls;

9 - as in the case of ball 7, lie on two granules, touch the upper and side walls;

10 - as in the case of ball 8;

11 - as in the case of ball 9.

Between the layers, two types of cavities are formed: tetra- and octahedral from the contact of four and six granules (Fig. 6), therefore:

12 - balls (Fig. 4), the dimensions of which correspond to the cavity of the tetrahedron;

13 - balls whose sizes correspond to the cavity of the octahedron.

On the right side of the container 1 (Fig. 5), balls 7-9 are similar to the same balls on the left side. However, filling the cavities on the right side between the first (lower) and third layers is difficult, because the cavities have the character of an elongated tunnel. Therefore:

15 - balls are laid in the depths of the tunnel;

14 - between the balls 15 and the wall;

16 - double balls near the wall between the balls 14 (Fig. 3).

The sizes of the balls (table 1) were found by stereometry methods based on constructing the spatial arrangement of the corresponding elements. Table 1 shows: r is the radius of the balls, R is the radius of the granules. For example, ball 4 (Fig. 11) is located between the bottom and three granules, which are conventionally depicted as ellipsoids, and the centers of the ball and granules form an equilateral pyramid. Solving the spatial system of the pyramid, we find the dimensions of the ball 4.

The granules and balls of the container are stabilized in a rigid frame by irrigation of the entire layer with trickles of water at a speed not exceeding the rate of crushing of water droplets in an amount sufficient to form ice bridges between the granules due to the cold of the granules and the walls of the container.

After holding 1-3 s, the container is filled with water from one or several sides towards each other. The water flow rate is reduced in comparison with the prototype, because filling the intergranular space with balls reduces the size of the channels and gaps between the ice particles.

A positive effect of the proposed method is a significant reduction in the freezing time of an ice object (a plate, as well as a bar, a cube, etc.), primarily due to an increase in the share of ready ice, and secondly, due to an increase in heat loss through the balls in the cavities compared with water when cooling the total mass of the granulate, because thermal conductivity of ice is significantly higher than that of water.

Example 1. In a container 1 (Fig. 7) lay a layer of five rows of granules of a hexagonal structure, of which 3 rows - 5 granules each, and two rows - 4 granules each. Granules are laid in 4 layers: the first is the lower, the fourth is the upper. Between the granules and the side walls, as well as between the rows of granules, balls are laid, the rows of which are indicated in uppercase letters of the alphabet: “a”, “b”, etc.

In the rows "a" 2 pcs. (5) and 4 pcs. (3) found: 2 balls in pos. 5 (Fig. 6) and 4 balls in pos. 3.

In the rows "b" it is established: 7 balls in poses. four.

In 4 cavities “c”, 4 balls of poses are installed. 6, a total of 16 balls in a layer. The arrangement of the balls 6 is shown in FIG. 7, where on the model of capacity 1, tennis balls were used as granules 2, and wooden beads of suitable size were used as balls 6. Through the transparent wall of the end face of the tank, it is seen that 4 balls of poses enter the cavity of the 1st layer. 6.

In total, under the first (lower) layer, balls are installed: pos. 3-8 pcs. (rows “a”, 4 on the left and 4 on the right); pos. 4 - 28 pcs. (7 pieces in 4 rows "b"); pos. 5 - 4 pcs. (on the 1st ball in four corners, in the rows "a"); and at the ends pos. 6 - 16 pcs. (for one layer of granules 4 cavities, 4 balls each).

At the same time, we note that over the 4th layer of granules the same number of balls is placed as under the 1st layer (for example, ball 3, Fig. 4), because the location of the granules in these layers is the same.

The balloons between the 1st and 2nd layers of granules are shown in FIG. 8. A scheme is given for calculating the number of balls in cavities along longitudinal rows of stacking.

The calculation of the number of balls between the remaining layers is similar to the previous one and conditionally not shown. The total number of balls is presented in table 2.

It is seen that in the lateral wall cavities of each layer, the balls 7 between the granules are smaller in size than the balls 8 lying on the granules.

In addition, it is clearly seen that each granule of the 2nd layer (and the 2nd row, Fig. 9) forms with 4 granules (two 1st and 2nd layers) octahedral cavities, where the balls 13 are placed, and with granules of the 1st layer, tetrahedral cavities in which balls 12 are stacked.

At the same time, when laying layers, a situation arises of choosing options for combining the balls in size.

In the cavity on the left, you can place balls 11 with a certain degree of filling, or leave the granule of the upper row and place balls 10 with the addition of the already existing fraction of balls 4, which gives a higher degree of filling. In this example, balls 4 are used, therefore, in table 2 there is no number of balls 11.

The filling of the tank 1 (Fig. 1) with monogranules 2 is equal to 61.6%. After filling the voids with balls (Fig. 4 and Fig. 13), 81.7%, i.e. significantly higher than in the prototype.

The layer in the tank 1 (Fig. 3) is irrigated with water with a temperature of 0 ... 0.5 ° C, as well as with a higher degree of irrigation density from 2 to 6 dm ³ per 1 cm of layer height with an area of 1 m ² , because laying balls increases the specific surface of the layer of granules. The formation time of the rigid frame is the same as in the prototype, and is 1-3 s.

The frame freezes to the walls and does not float upon subsequent pouring of water between the granular space and the entire layer as a whole. Fill with water at a temperature of + 0.1-5 ° C. The water feed rate depends on the diameter of the granules. The diameter of the resulting gas bubbles for granules 15 mm in diameter is a maximum of 6 mm. The speed of their rise in water in the frame is less than 0.4 m / s. From here they find the rate of rise of the water level.

The freezing time of the layer of granules with water in the prototype is 2.71 hours (Fig. 2). According to the proposed method, the freezing time in the tank 1 is 1.87 hours under the same temperature conditions.

A view of the ice ball fractions is shown in FIG. 12. Fractions of ice balls are divided by the value of the diameter in accordance with the calculation of the size of the fractions. In FIG. 13 shows the sequence of laying balls between granules and a box-shaped wall.

Claims (4)

1. A method of freezing an ice plate, including filling a layer of oval-spherical ice granules in a box-shaped form, irrigation with water of a layer with a temperature of 0 ... 0.5 ° C to stabilize the frame and then filling it with water with a temperature of 0.1-5 ° C and speed level rise of less than 0.4 m / s, characterized in that the cavity of the layer both between the granules and the walls of the mold is filled with ice balls of the appropriate size, the layer is irrigated with water in an amount of 2 ... 6 dm ³ per 1 cm of layer height with an area of 1 m ² , and the fill is produced from two or more sides of the form. 2. The method according to p. 1, characterized in that the ice balls in the cavities of the layer correspond to the following sizes:

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