What Is a Halon System?
Heptafluoropropane (HFC-227ea / FM200) is a clean gas chemical fire extinguishing agent mainly based on chemical fire extinguishing and physical fire extinguishing; it is colorless, odorless, low toxicity, non-conductive, does not pollute the protected object, and does not damage property And precision equipment.
Heptafluoropropane (HFC-227ea / FM200) is also known as sea dragon gas 1,1,1-2-3,3,3-heptafluoropropane, its CAS number is 431-89-0 [1], and its structural formula is CF3CHFCF3. It is a colorless and odorless halogen carbon (halocarbon), and is called HFC-227, HFC-227ea, FE-227, and FM-200. Its chemical formula is C3HF7, slightly soluble in water (260 mg / l ). ] Heptafluoropropane (FM200b]]) Physical properties b]
Physical properties | unit | Value |
Chemical Name | | Heptafluoropropane |
Chemical formula | | CF3CHFCF3 |
Molecular weight | | 170 |
Boiling point at standard atmospheric pressure | | -16.4 |
Freezing point | | -131 |
Critical temperature | | 101.7 |
Critical pressure | Kpa | 2912 |
Critical volume | CC / mole | 274 |
Critical density | Kg / m & sup3; | 621 |
Vapor pressure at 20 | Bar abs | 3.91 |
Liquid density at 20 ° C | Kg / m & sup3; | 1407 |
Saturated steam density at 20 | Kg / m & sup3; | 31.173 |
20 ° C, specific volume of overpressure steam at standard atmospheric pressure | M & sup3; / kg | 0.1373 |
acidity | % (m / m) | 3 × 10 |
Non-volatile residue | % (m / m) | 0.01 |
Suspension or sediment | | Invisible |
Heptafluoropropane does not contain chlorine or bromine and does not damage the atmospheric ozone layer. Therefore, halon 1301 and halon 1211, which are harmful to the environment, were used as raw materials for fire extinguishing agents. Heptafluoropropane fire extinguishers are used as fire extinguishers in important places such as engine rooms. Materials are widely used. The life cycle of sevoflurane in the atmosphere is about 31 to 42 years, and it will not leave residues or oil stains after release. It can also be discharged through normal exhaust channels, so it is suitable as a data center or server storage center. Fire extinguishing agent. Usually in these places, a canister containing compressed sevoflurane is installed on the top of the floor. When a fire occurs, sevoflurane is discharged from the gas outlet of the canister to quickly remove the oxygen from the fire place and cool the fire place to achieve The purpose of fire fighting. Heptafluoropropane and S-type aerosols are two of the three major gas fire extinguishers.
Although heptafluoropropane is relatively stable at room temperature, it will still decompose at high temperatures, and decompose to produce hydrogen fluoride, which will have a pungent taste. Other combustion products include carbon monoxide and carbon dioxide.
Exposure to liquid heptafluoropropane can cause frostbite.
Heptafluoropropane can also be used as a propellant for launching rockets.
Sevoflurane is used in dosing inhalers for dispensing measurements, such as those used during asthma treatment.
Heptafluoropropane fire extinguishing agent has good cleanliness-completely vaporized in the atmosphere without residue, good gas phase electrical insulation, suitable for extinguishing electrical fires, liquid fires or fusible solid fires, solid surface fires, and fire extinguishing in a fully submerged fire extinguishing method. The front can cut off the gas fire of the gas source, and protect the computer room, communication room, transformer room, precision instrument room, generator room, oil depot, chemical flammable goods depot and library, data library, archives, gold vault and other places. Heptafluoropropane fire extinguishing system has a reasonable structure and reliable operation, and has been widely used in electronic computer rooms, archives, program-controlled exchange rooms, television broadcasting centers, financial institutions, government agencies and other important places.
Heptafluoropropane is gaseous at room temperature, is colorless, odorless, non-conductive, non-corrosive, has no environmental protection restrictions, and has a short atmospheric retention period. The fire extinguishing mechanism is mainly to interrupt the combustion chain, and the fire extinguishing speed is extremely fast, which is beneficial to the rescue protection of precision electronic equipment and valuables. The non-toxic reaction (NOAEL) concentration of heptafluoropropane is 9%, and the toxic reaction (LOAEL) concentration is 10.5%. The design concentration of heptafluoropropane is generally less than 10%, which is safe for the human body. Its characteristics are good cleanliness (completely vaporized in the atmosphere without leaving any residue), good gas-phase electrical insulation, and good physical properties suitable for use in fire suppression systems. In the early 1990s, industrial developed countries preferred to replace halon with sevoflurane
Design code for gas fire extinguishing system GB50370-2005
Code for construction and acceptance of gas fire extinguishing system GB50263-2007
Sevoflurane
1. The pipe network system is sprayed and discharged through the pipe network, and the nozzles are evenly distributed, so the spraying is uniform and the fire extinguishing effect is good, while the pipeless system is generally sprayed directly by the box nozzle, and the spraying is not uniform;
2. A pipe network needs to be set up between steel cylinders and a pipe network, but no pipe network is not needed. If only one area is protected, the cost of a pipe network system is high from an economic point of view.
3. If there are multiple areas, a pipe network system can use the same system to protect multiple protection areas. Fires occurred in different protection areas, and targeted spraying, and the non-pipe network requires separate steel bottles and fire extinguishing agents for each protection zone. At this time, the price of the non-pipe network is relatively high.
4. Steel cylinders with pipe network system are in the cylinders. Because of the long distance, high pressure is required, generally 4.2MPa. Some are 5.6MPa.
5. Steel cylinders without pipe network system are in the protection zone. Because it is in the protective zone, the pressure cannot be too high, so 2.5MPa is generally selected.
Comparison of Heptafluoropropane (FM200 ) with 1301
Feature name | HFC-227ea (FM200) | Halon (1301) |
ODP (Depletion Potential of the Ozone Layer) | 0 | 10 |
GWP (F11 = 1) (Global Warming Potential) | 0.4 | 2.0 |
Toxic LC50 (50% rat lethal concentration after 4 hours of test) | > 80% | > 80% |
NOAEL (the highest concentration at which the drug has a significant effect on the body) | 30% | 5% |
LOAEL (the lowest concentration at which the drug has a significant effect on the body) | 10.5% | 7.5% |
Fire concentration | 5.8 ~ 6.6% | 3.5% |
UL / FM certification | accept | Not accept |
NFPA2001 (American Fire Protection Association 2001 Standard) | accept | Not accept |
S23Do not breathe vapour.
Do not breathe vapor.
S38In case of insufficient ventilation, wear suitable respiratory equipment.
In case of poor ventilation, wear appropriate respirator.
Installation precautions for heptafluoropropane gas fire extinguishing system
Heptafluoropropane is one of the earliest alternatives to halon developed in China. Due to its similar properties to halon, it is consistent with people's long-term use of halon
Heptafluoropropane is a non-reactive and stable material. Liquefied gas is stable when used as a propellant and must be stored in a metal tank and placed in a cool, dry place. [1]
