Investigation of the air flow field in front of the reinforced slot exhaust hood

The paper deals with the investigation of air flow field in front of the reinforced slot exhaust hood with the workbench at the level of the lower edge of the exhaust opening. The reinforced exhaust hood, which is also known as the Aaberg exhaust hood, is the traditional exhaust hood equipped with an air supply jet that intensifies exhausting along the axis of the exhaust hood. By an adjustment of the air supply quantity, the reinforced exhaust hood can operate in traditional or reinforced modes. The investigation was made for the fixed air velocity in the exhaust opening and with three different momentum flux ratios of supplied and exhausted air flows. The air flow field was measured by six hot bulb thermo-anemometric sensors with the diameter of 3 mm in the vertical plane running through the axis of the exhaust opening. An obvious extension of the velocity plane in the reinforced modes was observed from the results of air velocity measurements.