Adsorption Process Extends Muffler Service Life 892573
Internal corrosion in mufflers caused primarily by exhaust condensate, is known to have a major impact on their durability. UOP's novel technology for reducing the corrosiveness of exhaust system condensate employs a small amount of unique zeolite adsorbent which, when the car engine is shut down, adsorbs the water and acid precursors from the gas phase in the interior of the muffler before they can condense and attack the mufflers internal parts. Vehicles exhaust gas desorbs the water and acid precursors while the engine is in operation, preparing the adsorbent for the next engine shutdown.
Data is presented from a series of 5 statistically designed vehicle fleet tests which demonstrate that the corrosion rates of actual muffler parts can be reduced by more than 65%, when zeolite adsorbents are inserted in the muffler. Both ASTM Gl type corrosion coupons and micrographic examination of muffler parts show the dramatic reduction in corrosion rates experience with zeolite equipped mufflers as compared to control populations from the fleet tests.
This proven technology enhances muffler service life with all types of corrosion resistant steels. A mathematical model for muffler service life that employs actual measured corrosion rates for various corrosion resistant steels, shows that a reduction in internal corrosion rate of 50%. due to the use of zeolite can actually increase service life of a muffler by up to 28%. In salt belt locations and up to 51% in sun belt areas.
The paper includes a discussion of the adsorption processes occurring inside the muffler, and their effect on the amount and pH of the exhaust condensate.