Freon is colorless gas or volatile liquid at room temperature, tasteless or slightly smelly, non-toxic or low-toxic, and its chemical properties are stable.
The use of chlorofluorocarbon refrigerants, such as dichlorodifluoromethane, has been restricted because they will destroy the atmospheric ozone layer. There have been many holes in the ozone layer on the earth, some of which have exceeded the area of Africa, which is largely due to the chemical properties of chlorofluorocarbons. Another harm of freon is the greenhouse effect.
Freon is generally a gas or liquid at room temperature, transparent, with low dielectric constant, high critical temperature and easy liquefaction.
Solubility: Freon and water are almost completely immiscible with each other, and the solubility in water is very small. Generally soluble in refrigeration oil, but at high temperature, freon will be decomposed from refrigeration oil. Therefore, there are heaters in the oil tanks of large chillers to keep a certain temperature to prevent freon from dissolving.
Boiling point: the number of chlorine atoms in the molecule increases, and the boiling point increases; As the number of fluorine atoms increases, the boiling point will decrease.
Freon is widely used as refrigerant, foaming agent and cleaning agent, and is widely used in household appliances, foam plastics, daily chemicals, automobiles, fire-fighting equipment and other fields.
The thermodynamic properties of freon refrigerants with different chemical compositions and structures are quite different, and they can be used in high-temperature, medium-temperature and low-temperature refrigerators to meet the requirements of different refrigeration temperatures. Freon refrigeration system includes high pressure system, low pressure system, oil circuit system and defrosting system. The equipment selection calculation of Freon refrigeration system is basically the same as that of ammonia refrigeration system. The selection of refrigeration compressor should be calculated according to the refrigerator load of refrigeration unit and the determined Freon refrigerant type, refrigeration condition and compressor type.
Polyurethane foaming agent is the product of cross combination of aerosol technology and polyurethane foam technology. Sponge state appears in two types: branch pipe type and gun type. As a foaming agent for microcellular foam plastics, polystyrene foam plastics can be generally divided into physical and chemical types, which are classified according to whether gas generation is a physical process (i.e. volatilization or sublimation) or a chemical process (i.e. destruction of chemical structure or other chemical reactions).
Polyurethane foaming agent is a one-component polyurethane foam caulking agent, commonly known as foaming agent, foam adhesive and PU caulking agent. British polyurethane foam is the product of the cross combination of aerosol technology and polyurethane foam technology. It is a special polyurethane product filled with polyurethane prepolymer, foaming agent, catalyst and other components in a pressure-resistant aerosol can. When the material is ejected from the aerosol can, the foamed polyurethane material will expand rapidly and solidify with the air or moisture in the contact matrix to form foam. Wide application range. It has the advantages of pre-foaming, high expansion and small shrinkage. The foam has good strength and high adhesion. The cured foam has many effects, such as caulking, bonding, sealing, heat insulation, sound absorption and so on. It is a convenient environmental protection and energy-saving building material, which can be used for caulking sealing, gap filling, fixed bonding, heat preservation and sound insulation, and is especially suitable for sealing and waterproofing between plastic steel or aluminum alloy doors and windows and walls.