Production and storage of dry ice 2007-04-1121:02 Liquid carbon dioxide will be liquefied at 20℃ and 5.73MPa.
Reducing the pressure of liquid carbon dioxide, part of liquid carbon dioxide evaporates and absorbs a lot of heat, so that the other part of carbon dioxide cools into a snow-like solid. Compacting snow-like solid carbon dioxide to obtain dry ice. (Or liquid carbon dioxide can be cooled to -2 1. 1℃ and the pressure is 0.4 15MPa, or solid carbon dioxide can be formed. )
The simple method is to put a canvas bag on the mouth of the container containing liquid carbon dioxide, and then open the container to release carbon dioxide, so that some dry ice can be collected in the pocket. Mass production needs a special dry ice maker.
Dry ice should be stored in high-pressure steel cylinders. If there is no high-pressure steel cylinder, it can be stored in the freezer of the refrigerator for 5 ~ 10 days.
How to make the materials needed for dry ice? And practice
The invention relates to a preparation process of dry ice, which comprises the following steps: firstly, putting carbon dioxide into a container, then putting it into a cooling chamber for preliminary pre-cooling treatment, wherein the pre-cooling temperature is-10-20 DEG C, standing for10-20 minutes, and then entering a forced refrigeration room for forced refrigeration, wherein the refrigeration temperature is-80 DEG C-10 DEG C. Advantages: simple process and easy manufacture. The dry ice made by this method has high density, good compactness, crystal color and long volatilization time, and can be used in the production of various beverages and the cleaning project of dry ice. Patent * * * Project 1. A process for preparing crystalline dry ice is characterized in that the process for preparing crystalline dry ice is as follows: (1), firstly, liquid carbon dioxide is injected into a special container, and forced fins are installed outside the container, so that the heat dissipation performance is good; (2) putting a container filled with carbon dioxide into a primary cooling chamber for pre-cooling, wherein the pre-cooling temperature is-10-20 DEG C, and standing for10-20 minutes; (3) cooling the cooled carbon dioxide at-80℃-120℃ for 20-30 minutes; (4) after cooling, making crystalline dry ice in a container; (5) entering a demoulding chamber, and performing micro-thermal demoulding; (6) After demoulding, high-density crystalline dry ice is obtained.
How to make dry ice by yourself
At normal temperature and pressure, carbon dioxide is gas and dry ice is solid carbon dioxide. Theoretically, as long as it is below its sublimation temperature, carbon dioxide can be solidified into a solid state to obtain dry ice; But in fact, how does the general equipment reach this temperature?
At present, dry ice is usually pressurized at room temperature to obtain liquid carbon dioxide, and then evaporated at low temperature. In the evaporation process, part of the liquid is cooled and solidified to obtain dry ice.
Dry ice can be made by a dry ice maker. Its raw material is not direct gaseous carbon dioxide, but liquid carbon dioxide, which still solidifies into solid particles after evaporation and cooling. About 40% of liquid carbon dioxide is converted into solid dry ice.
As a daily experiment, you can use an ordinary carbon dioxide fire extinguisher: turn on the safety of the fire extinguisher and quickly release the gas in the cylinder. You can see the white "snowflake" falling near the nozzle, that is, dry ice, because the gas in the steel cylinder absorbs heat and expands rapidly near the nozzle, so that the nearby temperature drops rapidly to form a low temperature, and some carbon dioxide solidifies into a solid state in this environment.
This test should pay attention to safety and operate in strict accordance with the operating procedures of carbon dioxide flower killer. Don't touch the metal nozzle directly with unprotected hands, just grab the wooden handle and don't spray people.
How to make dry ice
Shenzhen People Dry Ice: You can make it interesting. If it works, you can't do it. You have to go to the factory that produces dry ice. You can do this for fun, but the dry ice you make is irregular. You can use a carbon dioxide fire extinguisher, but it won't cost much. Find a cloth bag, open the carbon dioxide fire extinguisher, put the cloth bag tightly at the outlet of the fire extinguisher, and press the handle to release carbon dioxide. There will be dry ice in the cloth bag soon, so be safe.
How to make your own dry ice at home?
Making dry ice requires special compressors, freezers, flash tanks and other equipment, which are not available at home. And there is no special protective clothing, which is easy to cause cold burns.
How to make dry ice at home
All you can do is a lot of carbon dioxide, and it needs to be kept in the refrigerator for a long time.
How to make dry ice (solid carbon dioxide) at home
Buy a carbon dioxide cylinder, find a mold, open the valve head of the carbon dioxide cylinder, pour it into the mold at 45 degrees, and make dry ice.
What exactly is dry ice? How to make dry ice? . What is the function of ordinary dry ice?
Dry ice is solid carbon dioxide, which is condensed into colorless liquid under the pressure of 6250.5498 kPa, and then rapidly solidified under high pressure. Dry ice is volatile and sublimated into non-toxic and odorless gas carbon dioxide, which is 600-800 times larger than the solid volume, so dry ice cannot be stored in containers with completely sealed volume, such as plastic bottles, and it is easy to explode when mixed with liquids.
Dry ice has a wide range of uses, mainly in the following ways:
1. Restaurant decoration, gas creation, film and television special effects, stage and venue smoke manufacturing;
2. Storage and transportation of frozen food;
3. Frozen preservation of poultry meat;
4. Air and sea transportation need to freeze demand for a long time;
5. Medical cryopreservation;
6. Heat treatment and low temperature shrinkage of metal parts;
7. Frozen food preservation and emergency refrigeration in case of power failure in fresh supermarkets;
8. Anhydrous refrigeration and fire fighting;
9. Industrial cleaning, descaling, etc.
How to make dry ice at home? 10 point
Making dry ice requires special compressors, freezers, flash tanks and other equipment, which are not available at home. And there is no special protective clothing, which is easy to cause cold burns.
How to make dry ice?
You can make a lot of dry ice with a dry ice machine. The raw material for producing dry ice by dry ice machine is not gaseous carbon dioxide, but liquid carbon dioxide, which is solidified into solid particles by evaporation and cooling. About 40% of liquid carbon dioxide is converted into solid dry ice. So how to make dry ice in the laboratory?
Laboratory preparation of dry ice
As a daily test, you can use ordinary carbon dioxide fire extinguishers. Open the fire extinguisher safety, turn on the switch, and quickly release the gas in the steel cylinder. You can see the white "snowflake" falling near the nozzle, which is dry ice. Due to the rapid endothermic expansion of the gas in the steel cylinder near the nozzle, the nearby temperature drops rapidly to form a low temperature, and some carbon dioxide solidifies into a solid state in this environment.
I hope to adopt.