Static Condition Differences in Conventional and Inclined Air-Curtain Range Hood Flow and Spillage Characteristics

摘要

Flow and spillage characteristics of conventional and air-curtain range hoods under static condition were experimentallynstudied, and their differences in physical mechanisms were compared. Two oil pans containing hotnoils heated to 2308C by electric heaters were placed on a countertop to simulate the cooking condition.nLarge amount of oil fumes were generated and rose from the oil pans. Flow features were examined using laserlight-nsheet-assisted oil fume flow visualization method. Local-averaged spillages of tracer gas (sulfur hexafluoride)nin the front and lateral planes of the range hoods were detected by employing the tracer-gas concentrationndetection technique. For the conventional range hood, the flow visualization showed two mostnprobable locations for spillages: the region near the front edge of countertop due to the boundary-layer separationnand the region around the lower edge of the hood side panels due to the expansion effect of hot plumes.nDetected local-averaged tracer-gas concentrations around these two locations correlated well with the results ofnflow visualizations. No significant spillages of oil fumes or tracer-gas concentration was observed or detectednaround the front and lateral planes of the air-curtain range hood. Around the front edge of countertop, thendetected tracer-gas concentration of the conventional range hood was larger than that of the air-curtain rangenhood by about three orders of magnitude. Overall, the air-curtain range hood presented drastically smallernspillages than the conventional range hood.