Decode the half-day melting ice making technology

Let's find a scientific solution about the process of making dry ice and unexpected uses from them.

Recently, many villagers were confused about the information that some shops used a special type of ice cubes, to go out into the air for a long time but not melted - or melted very little. . When drinking water with this type of stone, many people have a feeling of burning throat or holding a stone tablet which has a burning phenomenon in their hands .

So what is the scientific mechanism to create this special stone? Are they harmful to health?

Through verification, this is dry ice, also known as smoky stone, CO ₂ rock, smoke ice . Different from normal stone made from frozen water, dry ice is produced by compressing carbon dioxide gas. (CO ₂ ) into liquid form, remove heat during compression, then let liquid CO2 expand rapidly.

This expansion reduces the temperature and causes part of CO ₂ to freeze into "snow". After that, the "snow" part will be compressed into large pellets or blocks.

The temperature of dry ice is very low, about - 78.5 degrees C, so when sublimating into steam, it is not liquefied.

Precisely because of the low temperature (about - 78.5 degrees C) and when "sublimation" , evaporates into gas rather than ice, melting into water. For that reason , dry ice is often used to cool or preserve fresh vegetables and seafood.

In addition, dry ice is also used to preserve biological tissue in medicine, preserve corpses, create smoke effects on the stage . When dry ice comes into contact with water, it forms and forms a mist form. thick white blind.

When dry ice comes into contact with water, a thick white mist forms.

Although in nature, dry stone is harmless but if not used properly, it is very susceptible to CO ₂ poisoning , burns, even death. Because it is produced by compressing CO2, when melting, dry ice will form CO ₂ layer.

When drinking water containing dry ice, or letting large blocks of dry ice in a closed room, the body will have a phenomenon such as CO ₂ poisoning. Accordingly, patients will have asthma attacks, heart failure, more severe than coma, if the province also left sequelae like memory loss.

With low temperature, dry ice can cause cold skin (cold burn phenomenon), throat irritation (when using water containing dry ice). Therefore, you should use gloves when holding dry ice . If using dry ice in a closed room, good ventilation is required.