SELF-CLEANING ROTARY HEAT EXCHANGER

摘要

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 of the heat exchanger is located relative to the rotor so as to lie in the gas flow boundary layer established by the latter. The case is provided with a boundary layer purge port in the hot gas chamber. An airfoil 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 or contamination products out through the purge port. The boundary layer airflow cleans both the interior of the case and the rotor, 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 or time without buildup of contaminants within the heat exchanger case.