Evaporators automotive

These are carbon monoxide, CO, unburned hydrocarbons (HC), and the nitrogen oxides, NO. In the U.S.A., a program called Auto/Oil (Burns et al., 1992), conducted by automotive manufacturers and petroleum companies, examined the effect of overall parameters of fuel composition on evaporative emissions and in the exhaust gases. The variables examined were the aromatics content between 20 and 45%, the olefins content between 5 and 20%, the MTBE content between 0 and 15% and finally the distillation end point between 138 and 182°C (more exactly, the 95% distilled point). 

Adhesives. Contact adhesives are blends of mbber, phenoHc resin, and additives suppHed in solvent or aqueous dispersion form they are typically appHed to both surfaces to be joined (80). Evaporation of the solvent leaves an adhesive film that forms a strong, peel-resistant bond. Contact adhesives are used widely in the furniture and constmction industries and also in the automotive and footwear industries. The phenoHc resins promote adhesion and act as tackifiers, usually at a concentration of 20—40%. In solvent-based contact adhesives, neoprene is preferred, whereas nitrile is used in specialty appHcations. The type and grade of phenoHc resin selected control tack time, bond strength, and durabiHty. 

H. M. Haskey, W. R. Cadman, and T. E. Liberty, The Development of a Real-Time Evaporative Emission Test, SAE 901110, Society of Automotive Engineers, Warrendale, Pa., 1990. 

The generation of au pollutants, ineluding VOC s, from automotive vehieles was identified to eome from two prineipal sourees vehiele exhaust emissions, and fuel system evaporative emissions [4], Evaporative emissions are defmed as the automotive fuel vapors generated and released from the vehiele s fuel system due to the interactions of the speeific fuel in use, the fuel system characteristics, and environmental factors. The sources of the evaporative emissions are discussed below and, as presented m the remainder of this chapter, control of these evaporative emissions are the focus of the application of activated carbon technology in automotive systems. 

As initially discussed in Section 3, carbon canisters are used in the automotive emission control system to temporarily store hydrocarbon vapors. The vapors are later purged into the air charge stream of the air induction system, thus regenerating the carbon canister. Carbon canister design is dependent on the characteristics of the vapors sent to the canister and the amount of purge air available. In the following section, factors that affect the performance of the evaporative emission control system will be discussed. 

The role of activated earbon in the eontrol of automotive evaporative emissions is... 

Automotive evaporative emissions have been identified as a source of HC compoimds that can contribute to smog pollution. 

Benzene is a known carcinogen. The U.S. Environmental Protection Agency (EPA) has identified benzene as a toxic air pollutant (TAP). Benzene is present in automotive evaporation, refueling vapors, and exhaust. 

Most AR coatings are still produced by evaporation but CVD is gradually introduced particularly in applications with three-dimensional surfaces or deep recesses. AR coatings are used in numerous applications, which include lasers, lenses for cameras and binoculars, instrument panels, microscopes, telescopes, range finders, etc., as well as on automotive and architectural glasses. 

Applications of activated carbons are discussed in Chapters 8-10, including their use in the automotive arena as evaporative loss emission traps (Chapter 8), and in vehicle natural gas storage tanks (Chapter 9). The use of evaporative loss emission traps has been federally mandated in the U.S. and Europe. Consequently, a significant effort has been expended to develop a carbon adsorbent properly optimized for evaporative loss control, and to design the on board vapor collection and disposal system. The manufacture of activated carbons, and their preferred characteristics for fuel emissions control are discussed in Chapter 8, along with the essential features of a vehicle evaporative loss emission control system. 

Evaporative processes are very important in the weathering of volatile petroleum products and may be the dominant weathering process for gasoline. Automotive gasoline, aviation gasoline, and some grades of jet fuel (e.g., JP-4) contain 20 to 99% highly volatile constituents (i.e., constituents with fewer than nine carbon atoms). 

As a result of atmospheric pollution levels that exceed the National Ambient Air Quality Standards (NAAQS) in many parts of the United States, both the federal government and the State of California have implemented standards for exhaust and evaporative emissions from new vehicles (see Exhaust control, AUTOMOTIVE). The first of these standards went into effect in 1968 and mandated that the vapors from the vehicle crankcase be routed back through the engine and burned. Since then, the standards have continued to grow stricter. Table 7 shows the federal exhaust emission standards and Table 8 shows the more stringent California standards. California has mandated that starting in 1998 a certain percentage of new vehicles sales must be zero emissions vehicles (ZEV). 

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