The degreasing solvent of pipeline and equipment usually uses carbon tetrachate or hexachecane, both of which have toxicity. Because there is also the danger of combustion and explosion in dicchloroethylene, the most commonly used solvent is carbon tetrachluene.
Carbon chloride is poisonous to human body. It is the solvent of fat, which has powerful anesthesia effect and is easy to be absorbed by skin. Carbon chloride poisoning can cause headache, coma, vomiting and other symptoms. Carbon chloride is stable under 500℃. When exposed to fireworks and the temperature rises to above 500℃, carbon tetrachite vapour and vapor can produce photogas. Under normal temperature, the interaction between carbon tetrachite and sulfuric acid can also generate light gas. Light gas is a highly toxic gas, and extremely tiny amount can also cause poisoning. In addition, the chemical reaction between carbon tetrachite and alkali will generate methane and become invalid. Therefore, the following points should be paid attention to when using carbon tetrachite degreasing:
1) degreasing should be conducted in the open air or in a well-ventilated place. The staff should take anti-virus protection measures, wear multi-layer masks and rubber gloves, and wear aprons and long boots. You should also wear a gas mask when the concentration is high.
Under the condition of working continuously for 8 hours, the content of carbon tetrachhide in the air should not exceed 0.05 mg/L.
2) fireworks are strictly prohibited at the degreasing site.
3) the solvent is forbidden to contact with strong acid.
4) The solvent should be kept in a sealed container and should not be in contact with alkali to prevent deterioration.
5) the parts which need degreasing should not be stained with water before degreasing.
6) when the valve is degreasing, it should be disintegrated and soaked in carbon tetrachite solution 4 ~ 5 min, not too long.
7) The skim parts can only be assembled and used after being dried by nitrogen or dry air. Otherwise, corrosion and rust are easy to occur.
8) when the tube-type condensing evaporator is degreasing, it is necessary to strictly prevent the carbon chloride accumulation in the heat exchange tube. Especially heat exchange tube quilt solder etc. debris blocked when Must attention. After degreasing, apply hot air to blow it away until it is odorless. If there is carbon chloride deposit in the tube, it will freeze and expand after it is put into operation, and the tube will be expanded and cracked. At the same time, when there is water after thawing, it will produce strong chemical corrosion, which can corrode through the 0.5mm thick tube.
