JPS58172215A - Method for preparing block of dry ice - Google Patents

Abstract

PURPOSE:To obtain the titled dry ice block of larger volume in the optimum state by repeating a pressing stage >=2 times while making the molding rate proper when snow produced by spraying liquefied CO2 into a molding chamber is press-molded. CONSTITUTION:Liquefied CO2 is sprayed into a molding chamber 1 from a nozzle 5 through piping 3 and a valve 4 to produce snow. By lowering the pressing plate 6, the snow is pressed against the sliding lid 7 to form block-shaped dry ice (expressed as a moldedproduct hereunder), the lid 7 is slid, and the molded product is taken out by pushing. At this time, in the 1st spraying stage, snow is produced by an amount corresponding to a proper molding rate for the volume of the chamber 1, and the 1st pressing stage is carried out to form a molded product 8. In the 2nd spraying stage, snow is produced by an amount corresponding to a proper molding rate for the volume given by subtracting the volume of the product 8 from the volum of the chamber 1, and the 2nd pressing stage is carried out to form a molded product 9. Since the products 8, 9 are easily fused into one body, a large-sized molded product is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for forming block-shaped dry ice in a dry ice forming machine.

In recent years, block-shaped dry ice has been used for multiple purposes due to its high practicality, such as being a convenient cryogen to carry and being easy to handle as it changes from a solid phase to a gas phase after its function as a cryogen is completed. has been done. This block-shaped dry ice is formed by a spraying process in which liquefied carbon dioxide gas is sprayed into the forming chamber of a dry ice forming machine to produce snow-like dry ice (hereinafter referred to as snow), and a pressing process in which the snow is compressed. However, in order to perform good molding at this time, it is necessary to control the amount of agate produced within the molding chamber. For example, if the amount of snow is too large, the liquefied carbon dioxide gas will not be sufficiently vaporized and solidified during the blowing step, and the formed block of dry ice may burst immediately after the pressing step.

On the other hand, if the amount of snow is too small, a large cavity will be formed in the snow generated in the spraying process near the spray nozzle, and if the pressing process is continued as it is, the cavity will not be sufficiently suppressed, resulting in block-like dryness. The density of the ice cream does not become uniform and molding becomes unnecessary. That is, in order to obtain optimal block-shaped dry ice, the amount of snow must correspond to the volume of the molding chamber.

The ratio of the volume of the block-shaped dry ice after molding to the volume of the molding chamber (hereinafter referred to as the molding rate) has been considered empirically in the past, and even in ordinary equipment, the ratio of the volume of the block-shaped dry ice after molding to the volume of the molding chamber is: The amount of snow was determined and manufactured. In other words, it has usually been manufactured using a molding machine having a molding chamber with a volume corresponding to the desired weight and density. Therefore, dry ice molding machines using conventional molding methods can only mold block-shaped dry ice of a specific size. I had to replace it with power.

The present invention has been made based on various studies based on the above-mentioned findings.Although already formed block-shaped dry ice does not fuse with each other, the block-shaped dry ice after forming easily fuses with the dry ice being formed, and as described above. From the correlation between the molding chamber and the amount of dry ice, it is possible to mold 7 pieces of dry ice by repeating the spraying process and the subsequent pressing process one or more times while maintaining a good molding rate. We have discovered that plotter-shaped dry ice with a larger volume and unit cost can be produced under optimal conditions. The method of the present invention will be explained in detail below with reference to the drawings.

Fig. 1 is a schematic diagram showing the main parts of a dry ice molding machine, and the peripheral wall 2 of the molding chamber 1 is made of a φ material, such as sintered metal, that allows gas to pass through easily but powder does not pass through. . The liquefied carbon dioxide stored in an external liquefied carbon dioxide storage tank (not shown) reaches the nozzle 5 via the pipe 3 and the valve 4.
It is sprayed into the molding chamber 1 from the nozzle 5, a part of which is vaporized and diffused to the outside from the peripheral wall 2, and the remainder becomes snow and is sprayed into the molding chamber 1.
It accumulates inside. Next, the press plate 6 descends and presses the Snok against the slide lid 7@, and a block-shaped dry ice is formed.
is opened, and the press plate 6 is lowered again and pushed out. Then, after the press plate 6 is raised, the slide lid T is closed to proceed to the next molding, and in this way, block-shaped dry ice is continuously molded.

With such an apparatus, the method of the present invention will be explained with reference to Figure 1.2, for example, in the case where the spraying step and the breath movement are repeated twice. In the II/th spraying step, after spraying an amount of snow that matches a good molding rate to 10 volumes of the molding chamber,
Perform the second pressing process.

The horizontal line part indicated by 8 in the figure is the first spray, press error 1.
The block-shaped dry ice formed by i is shown.

Subsequently, in the spraying step of the third circle, an amount of agate that matches a good molding rate is sprayed to the volume obtained by subtracting the volume of the block-shaped dry ice 8 for the number of sheets/time from the volume of the molding chamber. Afterwards, a second pressing process is performed. 9 in the diagram
Since the amount of cracking in the vertical line portion shown by is set to an amount consistent with a good molding rate, no inconvenience will occur.

In addition, when carrying out the method of the present invention, the nozzle 5 is located at a position where the final spray can be performed, that is, on the press plate 6 side, but in this case, snow may enter the nozzle 5 during the final pressing process. There is no problem, and the amount of snow can be adjusted each time by making the valve 4 an automatic valve such as a solenoid valve and setting the opening and closing times using a timer or the like.

This will be explained below using examples.

〔Example〕

After molding, /JJI/l (When molding block-shaped dry ice with a density of D using a molding machine having a molding chamber with a volume of I1.2t, At is molded in the first time, W is molded, and /l is molded in the second time. Then, a total of 3 tons of block-shaped dry ice was produced *b.In this case, 3 tons of block-shaped dry ice was molded in the molding room of the station, so the molding rate was 7%.On the other hand, in the conventional molding Since this method can only produce 2 tons of block-shaped dry ice, the molding rate is quite high.It can be seen that the molding method of the present invention has a higher molding rate than the conventional molding method. In addition, the appearance of the block-shaped dry ice produced in *b shows that the joints of the first molded part and the second molded part are completely fused and become one body, even if you hit it with a hammer, etc. There was no separation at the joint.

As described above, the molding method of the present invention has been developed based on the discovery of the correlation between the volume of the molding chamber and the amount of snow, and that the block-shaped dry ice after molding is well fused with the block-shaped dry ice during molding. By actively utilizing correlation and fusion, the molding rate of the molding machine has been improved from the conventional 30-low to 70-1. In addition to the ability to produce block-shaped dry ice, the seven dry ice molding machines can now produce block-shaped dry ice in several sizes, which has the effect of making it easier to adapt to various uses.
・Effective when molding block-shaped dry ice. Furthermore, the molding method of the present invention is practical because it does not require any changes to the press pressure, oil pressure, etc. of a conventional dry ice molding machine.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing the main parts of a dry ice molding machine, FIG. 1 shows the method before the method of the present invention is carried out, and FIG. 2 shows it after the method is carried out. 1 is the molding chamber, 2 is the peripheral wall, 3 is the piping, 4 is the valve, 5 is the nozzle, 6 is the press plate, T is the slide lid, 8 is the patent applicant: Japan tR Co., Ltd.

Claims (1)

[Claims] Block-shaped dry ice is formed by a spraying step of spraying liquefied carbon dioxide gas into a forming chamber of a dry ice molding machine to produce snow-like dry ice, and a pressing step of compressing and molding the snow-like dry ice following the spraying step. In the method, snow-like dry ice is produced at a forming rate corresponding to the volume of the forming chamber, and after being pressed and formed, snow-like dry ice is produced at a forming rate corresponding to the remaining volume of the forming chamber. 1. A method for forming block-shaped dry ice, characterized in that a single block-shaped dry ice is obtained by producing and pressing.