ENGINE EXHAUST TEST EQUIPMENT
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ALTAMIRA INSTRUMENTS The First Name in Custom Reactor Systems ENGINE EXHAUST TEST EQUIPMENT Why Exhaust Testing? At Altamira Instruments we are constantly encountering requests for reaction units and characterization equipment that are useful for testing real or simulated exhausts of various types of motor vehicle engines, from car gasoline engines to large diesel trucks. Although each is a special case, through many years of experience we have learned how to make units useful for specific tests and thus provide reliable test equipment to our customers. Background It is estimated that over 65% of all air pollutants in the U.S. come from on-road vehicles, compared to only 1% from industrial sources. In order to combat this, Congress first passed the Clean Air Act in 1970, in part establishing controls over the pollutants emitted from mobile sources. The first catalytic converters for automobiles came about in the early- to mid-70s and are collectively known as two-way catalytic converters, in that they were designed to only control the emissions of hydrocarbons and CO. Further refinements to the Clean Air Act in the 1980s led to the addition of control of nitrogen oxides, NOx, and the development of the currently used three-way catalytic converters. In 1990 limits in the sulfur content and other emissions of dieselfuels were mandated to be phased over several years starting in 1993.

Modeling Reactions Of Emmision Gases Using Benchcat Reactors The type of equipment needed to characterize and evaluate catalytic converters requires the utilization of an actual catalyst sample (i.e., not a crushed sample) and the simulation of actual conditions occurring in the exhaust gases. Some of these conditions are: • Very high flow rates. • Rapid temperature changes in the orders of hundreds of degrees during operation. • Complex mixtures of varying compositions, including hydrocarbon fuel, unspent hydrocarbons, NOx, carbon oxides, etc. • Rapidly varying changes in gas composition,...

TABLE 1. Controlled temperature changes that can be achieved in an Altamira Instruments test unit. Total Flow Rate (SLPM) Rate of Change (oC/min) Feed Composition Typical engine exhausts are extremely complex and have to be taken into account when designing test units. Feeds having 20 or more components, each precisely regulated, are not unusual. A typical fuel mixture may contain: inerts, such as nitrogen or argon, CO2, CO, water vapor, air, sulfur oxides (typically SO2), various NOx, hydrocarbons (propane, vaporized VOCs). These have to be fed at different points upstream of the reactor...

Particulates In Exhaust Of particular concern to diesel engine manufacturers is the control of particulates or soot generated during combustion and which is now also regulated under the Clean Air Act. Thus, a successful catalyst must be able to burn-off any produced soot. Again, Altamira Instruments has been a leader in developing technologies to feed soot onto a catalyst. In one instance – see Figure 3 – a fluidized bed was used for delivering a controlled amount of soot to a catalyst. Figure 3. Test unit for delivering particulates to a catalyst via a fluidized bed. Analysis Of Products...