| 摘要 |
<p>The invention relates to a rotary, Perkins tube heat exchanger for processing hot contaminated gas flows emanating from appliances such as laundry driers, grain driers and the like. The case (10) of the heat exchanger is located relative to the rotor (12) so as to lie in the gas flow boundary layer established by the latter. The case (10) is provided with a boundary layer purge port (56) in the hot gas chamber (28). An airfoil (60) extends inwardly from the case into the gas flow boundary layer. It causes increased local turbulance in the boundary layer gas. It also diverts a predetermined proportion of the boundary layer gas and its burden of contamination products out through the purge port (56). The boundary layer airflow cleans both the interior of the case (10) and the rotor (12), even though the rotor is characterized by the presence of a multiplicity of small openings. The device thus is rendered self-cleaning and may be operated for extended periods of time without buildup of contaminants within the heat exchanger case.</p> |
