Combination catalytic converter and heat exchanger that maintains a

Abstract

A combination catalytic converter and heat exchanger unit that controls the temperature of one or more catalytic converters within their efficient conversion operating temperature ranges. The unit includes a plurality of spaced apart tubes through which the exhaust emissions flow through the unit. Each of the plurality of tubes includes a substrate on which is formed a catalyst that reduces or eliminates harmful by-products in the exhaust emissions. A cooling system, such as a fan, forces a cooling fluid, such as air, around the tubes to cool the catalyst to be within its efficient operating temperature range. The tubes have a suitable diameter that allows the center of the tubes to be effectively cooled. The speed of the fan is controlled to variably adjust the temperature of the exhaust emissions in response to various input data, such as the temperature of the exhaust emissions at different locations in the exhaust path, engine speed and load, and the type of catalyst being used. The plurality of tubes can incorporate two or more catalysts that have different operating ranges so as to control the effectiveness of the conversion for increased efficiency and reduction of energy consumption. It is also possible to provide supplemental electrical heat to the plurality of tubes to extend the duration whereby the catalytic converter is operating within its efficient conversion window.