JPS58163423A - Method for dissolving liquid carbon dioxide in water - Google Patents

Abstract

PURPOSE:To make it possible to easily adjust moisture in stock liquid carbon dioxide, by contacting liquid carbon dioxide at a temp. of 0 deg.C or less with ice. CONSTITUTION:After the interior of a water adding vessel 1 is filled with ice, stock liquid carbon dioxide is introduced into he water adding vessel 1 from a pipe 2 and discharged from an arranged pipe 3 while directly contacted with ice but, during this process, ice is melted to be dissolved in the stock liquid carbon dioxide. When ice filling the water adding vessel 1 is brought to a supercooled state, no trouble takes place if the gas phase is sent to a dryice molding machine because the gas phase contains only slight moisture even if the stock liquid carbon dioxide in the gas-liquid two-phase stream is introduced at the initial stage of use of the water adding vessel 1. That is, moisture in the stock liquid carbon dioxide can be adjusted by a simple installation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for dissolving water in liquefied carbon dioxide gas (hereinafter referred to as LOO).

In general, LOO is often used in applications where moisture is averse, such as for welding, and therefore even LOO produced industrially has an extremely low moisture content of 3 to 5 PPM. However, when manufacturing dry ice, it is desirable that the moisture content is about 30 PPM. That is, generally dry ice is stored in a tank and subjected to 9 pressures of 20
Kf/cd, liquid temperature -20C, moisture 3-5PPMOJ material L
It is manufactured by spraying snow-like dry ice (hereinafter referred to as snow) into the molding chamber of a 5-ice ice molding machine, and then pressing the snow to form a block-shaped dry ice. At this time, the raw material L00 has a moisture content of 15 to 40 PPM, preferably 301' PPM.
It is known that when @li is melted, the produced block-shaped dry ice becomes hard and cracks better when crushed. Therefore, the raw material L00. It is desirable to hydrolyze a small amount of water into the raw material L00. To do this, the water pressure must be equal to or higher than the pressure of the raw material L00, that is, 20 Kp/ci, and the pressure must be higher than the pressure of the raw material L00. It must be kept from freezing at a beach temperature of -20C. Furthermore, raw material L00. It is not good if the water content is too much or too little, so the amount of dissolved water must be kept at a very small amount of 10 to 40 PPM.
These points have traditionally been viewed as difficult.

Conventionally, water to which a melting point depressant such as propylene glycol has been added is injected using a micro pump with high discharge pressure. In addition to requiring chemicals such as glycol, a precise flow rate adjustment mechanism is also essential to pressurize a small amount of water.Therefore, when producing dry ice by installing a dry ice molding machine in a dry ice consumption area, etc. However, there was a problem in that the equipment was not suitable for small-scale production VC.

The inventors of the present invention took into consideration the above-mentioned circumstances and focused on the fact that liquefied carbon dioxide gas at room temperature easily dissolves water. devised a method for dissolving water into nine raw materials, LCO, from within and without the need for injection means. That is, the present invention provides raw material L
The purpose of this method is to provide a method for easily dissolving water in OO, and its feature is to bring liquefied carbon dioxide gas below OC into contact with ice.

The present invention will be explained below with reference to illustrated embodiments.

Figure 1 shows an embodiment of the present invention. In the figure, 1 is a container whose inside is filled with ice using a water adder, and a pipe 2t3 is connected to the container. 4 is a lid of the water heater I, and 5 is a blow valve connected to the water heater IK. In such a structure, the raw material LCO is introduced into the water adder l from the pipe 2 and is brought out from the pipe 3 while coming into direct contact with the ice.
During this process, the ice melts and dissolves into the raw material LCO. When the amount of ice decreases, open the lid 4 and refill it. Also, if the ice melts and becomes water IC while the water heater l is not in use, open the blow valve 5.
Water is drained from the water. Here, the size of the ice in the water heater 1 may be arbitrarily determined by considering the flow rate of the raw material LOO passing through the water heater 1, the contact time with the ice, etc.
For example, if the size is about 21 squares, handling is easy. Next, as for the ice temperature, it is possible to use ice with an ice temperature close to OC, such as ice manufactured in a refrigerator or an ice compartment, but in this case, care must be taken when starting to use the water adder l. The raw material LOO1 that is introduced when starting to use the water adder 1 is usually a gas-liquid two-phase flow with a large amount of gas phase, and the gas phase in particular comes into contact with the ice and contains water to saturation, so this is the process of forming dry ice. When the dry ice is sent to the machine, the pressure drops in the valves and piping attached to the dry ice forming machine, resulting in oversaturation and the formation of water droplets. The water droplets may damage the seat portion of the valve or block the nozzle portion for producing snow, and the raw material LOO introduced at the beginning of use of the water adder 1 must be discarded.

As described above, if ice near the OC is used in the water heater 1, there will be a loss of waste of the raw material L00° at the beginning of use of the water heater 1, so it is desirable to use ice in a supercooled state. That is, if the ice filled in the water adder 1 is supercooled, the raw material L in a gas-liquid two-phase flow is
Even if OO, is introduced, the gas phase contains only a small amount of water, so there is no problem even if it is sent as is to the dry ice molding machine.

As for the supercooled ice, if it is cooled using dry ice produced by a dry ice molding machine, the temperature of dry ice is about -70C, so supercooled ice can be easily obtained. .

1 As described above, the present invention replaces the conventional method of injecting water into the raw material LOO from the outside by dissolving water from inside, and combines the raw material LOO with ice or supercooled dead water. Since it is characterized by contact, the structure is simple and the equipment is inexpensive.

Next, FIG. 2 is a book showing another embodiment of the present invention, so the same components as in FIG. 1 are given the same reference numerals.

In FIG. 2, raw material LOO is stored in tank 9.

is divided into two parts via piping 10, and a part is introduced into water adder 1 via valve 6 and piping 2, while the remaining part passes through valve 7, joins in piping 3, and enters dry ice via valve 8. It is introduced into the molding machine 11.

With the above configuration, the amount of raw material LOO to be introduced into the water adder 1111 can be arbitrarily controlled by adjusting the opening degree of the valve 7. Moisture content ζ can be easily adjusted. The opening degree of the valve 7 may be adjusted by checking the moisture meter A installed in front of the dry ice molding machine or by checking the condition of the dry ice after production.

As described above, according to the present invention, the moisture content of the raw material LOO can be easily adjusted using simple equipment, and there is no need for a precise flow rate adjustment mechanism for dissolving a small amount of water as in the past, so dry ice is consumed. It is suitable for small-scale production, such as when dry ice is manufactured by installing a dry ice molding machine on the ground, and is also useful for large-scale production, and has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, and FIG. 2 is a flow sheet diagram explaining another embodiment of the present invention. l is the water heater, 2.3 is the piping, 4 is the lid, 5 is the blow valve, 6
, 7.8 is a valve, 9 is a tank, 10 is a pipe, 11 is a dry ice molding machine, and A is a moisture meter.

Claims (1)

[Claims] A method for dissolving water in liquefied carbon dioxide gas of 1.0 C or less, the method comprising bringing the liquefied carbon dioxide gas into contact with ice. 2 Special feature, characterized in that the ice is filled in a water heater and the liquefied carbon dioxide gas is allowed to flow into the nuclear water heater! A method of dissolving water in the liquefied carbon dioxide gas according to item 1. 3. The claimed scope of the patent, characterized in item 1 or 2, is characterized in that the amount of dissolved water is adjusted by dividing the liquefied carbon dioxide gas into two parts, bringing a part of it into contact with ice, and then merging it with the remaining part. , the method of dissolving water in liquefied carbon dioxide gas according to item 2.