Dry ice
Dry ice is carbon dioxide CO2 in the solid state, and carbon dioxide is the gas the human body releases in the exhalation process. The plant uses it to manufacture food, but it becomes solid at -78.5 degrees Celsius. This is equivalent to -109.3 degrees Fahrenheit. Unlike regular ice, used to cool drinks, it does not melt at room temperature, but sublimates.
(i.e. it turns from a solid state to a gaseous state without passing through the liquid state). Dry ice is used to preserve perishable items for longer than regular ice does; Where dry ice must be handled with caution for fear of frostbite, when touched without using gloves, it may cause suffocation when inhaling smoke resulting from its transformation into carbon dioxide.
How to make dry ice
For the manufacture of dry ice; The carbon dioxide gas is converted into a liquid by cooling and pressure, then the liquid pressure is reduced, and it turns again into a gas very quickly; Which lowers the temperature and turns the gas into solid granules of dry ice, and at this stage dry ice can be formed and turned into pieces used to cool perishable materials.
to make dry ice at home; Safety procedures must be adhered to, wearing protective glasses, thick gloves, and obtaining a tank of carbon dioxide that is sold in diving equipment stores, or aquarium sales centers, in addition to ice bags, and a thick container, after which the tank mouth is covered with an ice bag tightly Then the tank valve is opened for a period ranging between 5-20 seconds, and after making sure that the valve is closed, the bag is removed from the tank nozzle, then the dry ice that formed in the container is kept without being covered.
Dry ice history
The first to discover dry ice was the French chemist Thelorier in 1835 AD; When he opened a cylinder containing carbon dioxide, he noticed that most of the gas had evaporated and a solid part remained at the bottom of the cylinder. In 1897, a doctor in the British Army Medical Corps named Herbert Samuel Elworthy obtained a patent for converting carbon dioxide into a Solid state, and in 1925 AD, dry ice began to be exploited commercially by Prest Air Devices; By making the first carbon dioxide fire extinguisher, inflating tires and other uses, and later the company (Prest Air Devices) was sold and the company (DryIce Corporation of America), owner of the Dry ice brand.
Dry ice uses
Some of the uses of dry ice are:
- Manufacture of juices and sparkling water.
- freezing of cutaneous warts; which facilitates their removal and preservation of medical samples; Especially biological samples.
- It eliminates insects such as bugs, wood beetles, and mosquitoes, and prevents the growth of bacteria, making it ideal for preserving flour, grains, and dry seeds.
- Delays the growth of yeast used in bread making.
- Keeps refrigerated food fresh for longer, and the fruit is firm and firm rather than saturated with water.
- The production of clouds of thick smoke or fog as special effects during parties, and this is done when dry ice interacts with water.
- Assistance in removing tiles from floors when replacing them; It works to break up the adhesive between the tiles.
- Cooling alcohol is used in marking animals, such as hunting dogs, livestock, and horses.
- Promote plant growth, and delay flower buds' growth during transportation.
- Accelerate firefighting operations .
- annealing and processing of plastics and rubber; Which facilitates their use in industry.
- Improving the porosity of irrigation wells, and improving the flow of water in them.
- Cleaning oil storage tanks, separating water from oil, and liquid carbon dioxide are used to improve oil flow in wells.
Tips and Advice
When dealing with dry ice, the following matters must be taken into account:
- Avoid touching it without wearing gloves to protect the skin from dry ice; Because its low temperature may cause burns to the skin. When touching dry ice, you should consult a doctor if blisters or crusts appear on the skin, and use antibiotic creams to avoid contaminating the place of infection, but if the skin is only red, this means that the burn is slight and will heal on its own within a few days.
- Avoid tasting or swallowing dry ice.
- Ventilate the rooms well when using it, due to the toxicity of carbon dioxide.
- Keeping dry ice in insulated refrigerated containers to keep it in the solid state for a longer period, by placing it in double paper bags with the container covered with a blanket for more protection, taking into account that the container is not tightly closed, because the transformation from dry ice to carbon dioxide gas generates pressure that leads to a container explosion.
- Avoid storing it in the freezer; Because its extreme cold may malfunction the thermostat of the freezer, and stop it from working, and this, in turn, leads to the consumption of dry ice to keep the food stored in the food freezer cold.
- Avoid buying more than needed dry ice; Because it will quickly turn into a gas; Approximately 2.25-4.5 kg of dry ice pellets or flakes will need 24 hours to sublimate; While larger pieces take longer.
- Keep children and pets away from dry ice storage areas.
- Placing dry ice over the food to be refrigerated; Because cold travels from top to bottom.
- Avoid placing dry ice in empty glass containers to avoid shattering. As a result of the high cold.