Dry Ice
Technology Term Definitions
Dry Ice
Dry Ice
Definition 1: Solid carbon dioxide (CO2), white. Under -78.5°C and atmospheric pressure, it sublimates into a gas. It is widely used as a cloud-seeding agent in artificial weather modification.
Applied Disciplines: Atmospheric Science (Level 1 Discipline); Atmospheric Physics (Level 2 Discipline)
Definition 2: Solid carbon dioxide.
Applicable Disciplines: Aquaculture (Level 1 Discipline); Fish Preservation and Processing (Level 2 Discipline)
Molecular Weight: 44.01
Density (solid) 1560 kg/m³ (-78°C)
Melting Point -57°C
Freezing point -78.5°C
Molecular Model of Dry Ice
Three-phase point - 56.6°C, 5.17 x 10^5 Pascals
Critical Point 31℃ 7.37E+6 Pascals
Physical Properties
Colorless and odorless gas with an acidic taste.
Solubility
Dissolves in water (1:1 by volume), partially forming carbonic acid.
Liquid to Gas Ratio: 8.726 SCF (Gas)/LB (Liquid -17.8°C, Pressure 21 kg/cm²)
Liquid to Solid Ratio: 0.46 (-17.8℃) 0.57 (-48℃)
Dry ice is the solid form of carbon dioxide, which is an odorless, colorless gas under normal conditions and naturally present in the air. Although carbon dioxide constitutes a relatively small percentage in the air (about 0.03% by volume), it is one of the important gases we are aware of. Dry ice is highly volatile, sublimating into a non-toxic, odorless gas, 1000 times larger in surface area than the solid carbon dioxide. Therefore, dry ice should not be stored in containers with good sealing and small volume, as it can easily explode. It is important to place dry ice in a well-ventilated area to allow the gas produced by its sublimation to be released, ensuring safety.
At room temperature and under a pressure of 6079.8 kPa, carbon dioxide is condensed into a colorless liquid, which then rapidly evaporates under low pressure, forming tightly packed, ice-like solid substances.
Its temperature is -78.5°C, which is dry ice. Dry ice has more than 1.5 times the cooling capacity of water ice. After absorbing heat, it sublimates into carbon dioxide gas, leaving no residue, toxicity, or odor, and has sterilizing properties. It is affected by heat
Dry ice sublimates directly without liquefying. It is the solid form of carbon dioxide, and due to its extremely low temperature of -78.5°C, it is often used to maintain objects in a frozen or低温 state.
At room temperature, when carbon dioxide gas is pressurized to approximately 101325 Pa, it will freeze into snowflake-like solid carbon dioxide when a portion of the vapor is cooled to around -56°C. The sublimation heat of solid carbon dioxide is veryAt -60°C, it has a value of 364.5 J/g, and when it vaporizes at atmospheric pressure, it can lower the surrounding temperature to around -78°C without producing any liquid, hence the name "dry ice."Dry ice can also be used for artificial rainmaking. When placed in the air, it can rapidly absorb a large amount of heat, causing the surrounding temperature to drop quickly and leading to the condensation of water vapor into tiny droplets, thereby achieving the purpose of precipitation. Additionally, substances like silver iodide (AgI) are also used.Share similar characteristics.
Application Scope
Dry ice applications in the electronics industry
Clean internal grease and dirt in cleaning robots and automated equipment; remove soldering paste, contaminated coatings, resins, solvent coatings, protective layers, and photosensitive corrosion inhibitors on printed circuit boards. Applications of dry ice in the field of refrigerated transportation.
Low-temperature transport for medical freezing purposes, as well as for special drugs such as plasma and vaccines.
Electronically低温 materials, long and short-haul transportation for precision components.
High-end food preservation and transportation, such as premium beef and mutton.
Due to the characteristics of dry ice, it has been used by some computer overclocking enthusiasts in recent years to cool down and overclock CPU/GPU processors. Impulse records.
Price
Prices vary, as dry ice is a common refrigerant, it's readily available at specialized chemical factories in major cities, costing between 10 to 15 yuan per kilogram, which is still acceptable for enthusiasts. Common types of dry ice include food-grade, medical-grade, and industrial-grade. Food-grade dry ice is commonly used for cooling food, widely employed in bars and restaurants, and is slightly more expensive than industrial-grade. If industrial-grade is unavailable, you can purchase food-grade dry ice from food sales departments. Dry ice sold in stores typically comes in block, granular, or powdered form. For overclocking, granular or powdered dry ice is used, and it's best to avoid purchasing blocks, as large pieces are very hard and difficult to break.
Be cautious when handling dry ice at all times and only touch it with thick cotton gloves or other protective gear! Prolonged direct contact with the skin can cause cellular freezing and injuries similar to minor or severe burns. Do not use dry ice in areas like car interiors or ship cabins, as the sublimated carbon dioxide can displace oxygen, potentially leading to shortness of breath or even asphyxiation!
Do not let children handle dry ice alone!!
2. Dry ice is extremely cold; do not place it in your mouth, and prevent frostbite at all costs!!
3. Always handle dry ice with thick cotton gloves, clamps, or other protective gear (plastic gloves are NOT effective in blocking!!)
4. Use dry ice in well-ventilated areas. Never place dry ice in a confined space with other materials!!
5. Dry ice should not be mixed with liquids.
Caution: Proper and safe handling of dry ice to prevent injury.
During overclocking, be aware that dry ice sublimates very quickly at room temperature and pressure; failing to use it promptly can result in it disappearing quickly, especially during summer. A 20-kilogram box of dry ice can completely sublimate after being left in a room at room temperature for 24 hours. Before using dry ice for cooling during overclocking, there are two important reminders: first, ensure good ventilation in the room, and second, wear protective gloves. As dry ice is a low-temperature substance, safety must be prioritized during use, as frostbite pain can be as intense as burn pain. Additionally, pay attention to the amount of dry ice added. Many believe that filling the entire chamber with dry ice will provide better cooling, but it can lead to excessive condensation, which, when dripping onto circuit boards, can cause accidents. In reality, once the processor reaches a stable operating state, there is a temperature balance point between cooling and heat dissipation, and adding too much dry ice will not lower the processor temperature further. Experienced extreme overclockers can effectively manage this balance point, achieving good cooling results with less dry ice.
Frostbite Symptoms and Treatment Measures
Frostbite Definition
Frostbite refers to damage to the skin and tissues of a body part due to prolonged exposure to cold temperatures.
Symptoms
Feel the skin very cold, and it may turn slightly red before frostbite occurs.
The skin will first lose its color, but as frostbite gradually forms, it may turn white or grayish with a yellow tint, or white with spots.
Blisters may form. There may be some pain, or you might not even realize you're frostbitten.
Initial symptoms at the frostbitten area (frostnip) are tingling, followed by numbness and stiffness, with the affected area appearing pale; if warmed, it can recover completely. If the initial frostbite is not treated, it may progress to superficial frostbite, at which point the skin and subcutaneous tissue are necrotic, the skin remains pale or slightly gray, feeling cold but soft; upon thawing, it becomes red and painful, developing large blisters similar to second-degree burns within one to several days; after a few more days, the blisters dry up and form black eschar, which, if no infection occurs, will eventually be replaced by new skin.
Treating Frostbite Measures
Move to a warm area and keep the affected area in a warm and dry environment. Remove any constrictive items to prevent them from being difficult to remove when swelling occurs. Keep the affected area warm by placing it in gradually adjusted warm water (38.8~40.5 degrees). Do not expose dry ice to cold again, elevate the affected area to reduce pain and swelling, then wrap the area with clean gauze and seek medical attention; the purpose of first aid is to restore the frozen body fluids to normal. Therefore, if the surrounding area of the affected area can be warmed up, it can be cured quickly. Do not immerse the affected area directly in hot water or use fire to warm the area, as this can worsen the frostbite. Since massage can cause complications, do not massage the affected area.
Note---Do not massage, bake, or pierce blisters to prevent infection of the affected area.
As we know, dry ice cleaning is also known as dry ice blast cleaning, CO2 cleaning, or low-temperature cleaning. The characteristics of dry ice cleaning technology distinguish it from other cleaning processes. The major benefits lie in the custom dry ice cleaning solutions we offer, which feature applicability, environmental friendliness, practicality, cost-effectiveness, and safety.
Dry Ice Cleaning Technology Applications
Dry ice cleaning technology involves rapidly freezing the item to be cleaned, causing it to form micro-cracks. Dry ice then forcibly enters these cracks, rapidly expanding and forcing the item to be stripped away. Therefore, it is classified as a "physical cleaning method." Theoretically, dry ice cleaning can replace traditional physical cleaning processes such as sandblasting, waterjetting, and wiping techniques.
Dry ice cleaning technology can also replace certain "mixed cleaning techniques," such as traditional methods like using degreasing agents to clean dirt, acid washing to remove rust from metal surfaces, and diluting paint with solvents.
However, from the perspective of industrial practicality, the application of dry ice cleaning technology is related to the national environmental awareness and legal requirements. That is, in cases where traditional processes fail to meet environmental standards, dry ice cleaning technology can be used to replace traditional cleaning methods. From a process standpoint, the principle of any cleaning process is to ensure that the item being cleaned is not damaged, thereby maintaining its integrity. Dry ice cleaning must also adhere to this principle. Dry ice cleaning involves spraying dry ice particles in a fog-like form onto the surface of the item, which must withstand a certain degree of wind pressure. If the item's surface cannot withstand this wind pressure, dry ice cleaning cannot be employed.
Dry ice cleaning is widely used in the nuclear energy, metallurgy, casting, petroleum, chemical industry, rubber, plastic, shipbuilding, automotive, food, pharmaceutical, machinery, printing, electricity, and electronics sectors...
Cost of dry ice cleaning
Another key issue in whether dry ice cleaning technology can replace traditional cleaning processes is the cost of the process. This necessarily ties into the consumption of dry ice, pressure levels, and the amount of flow, all contributing to cost considerations. However, the process cost of any cleaning method is directly related to the original condition of the item being cleaned and the required cleaning precision. Different levels of cleaning precision and varying cleaning conditions can result in significant cost differences.
Firstly, the main materials for dry ice cleaning are dry ice and compressed air, with an unlimited supply of compressed air that requires no transportation, thus eliminating raw material procurement and shipping costs. The primary material is dry ice. The cost of dry ice is calculable, as 3.0 tons of liquid carbon dioxide can produce 1 ton of high-quality dry ice.
The consumption of dry ice is a concern for users, as it is closely related to the cleaning conditions and precision. For substances with heavy oil污 and strong adhesion, such as paint, scale, carbon deposits, and weld slag, they must be removed by deep freezing and effective shock to cause the substances to crack and peel off layer by layer. Consequently, the amount of dry ice consumed increases, and so does the requirement for air pressure, leading to higher costs. However, for oil污 with low adhesion, strong compressed air is not necessary, and low-pressure cleaning can be employed, significantly reducing the dry ice consumption and lowering costs as well.
Additionally, dry ice cleaning is characterized by its speed. Dry ice has a high volatility, making slow operations impossible, and it also has a high stripping speed, thus achieving quick cleaning. Secondly, dry ice cleaning is a "dry process" that does not produce any conductive medium, preventing any residual conductive material from damaging devices, making it an optimal choice for items not suitable for "wet cleaning." Most importantly, dry ice cleaning does not generate secondary pollution, eliminating the need for recovery and treatment of cleaning media, significantly reducing costs.
As for the ultimate destination of the materials being removed, since dry ice cleaning is a physical cleaning process, in principle, the items being cleaned are merely stripped of their material, not vanished.
The disposition of the material removed by dry ice cleaning
