DESCRIPTION The equipment comprises a long smooth walled pipe connected to the suction side of an electrically driven centrifugal fan. The fan discharge pipe terminates in a flow control damper for closed conduit work or a plate containing a small aperture for jet dispersion measurements. Air enters the smooth walled pipe through one of the two flow measurement nozzles provided. Pressure tappings along the length of the pipe permit the pressure gradient to be determined. A bend or mitred cascade elbow may be fftted midway along the smooth wall pipe for comparison of pressure losses. Boundary layer growth is determined by the measurement of the velocity proffle at ffve stations along the pipe using a traversing Pitot tube. A conventional flow measuring oriffce plate is supplied for installing in the pipe upstream of the fan for additional demonstrations of pressure loss and recovery. Air-jet studies are carried out on the discharge side of the fan. A Pitot tube is traversed vertically and horizontally at different distances from the discharge oriffce to investigate the dispersion properties. The equipment is mounted on a floor-standing steel frame with an adjacent support for the extended suction pipe. Pressure measurements are made on a multitube inclinable manometer mounted on the support frame. An electronic manometer bank with data logging software is available as an accessory (order code H14-12).
TECHNICAL SPECIFICATIONS Centrifugal fan capacity: 218 l/s at STP Pipe velocity range: 0-35 m/s Inlet pipe: dia. 80mm length 2.75m Interchangeable nozzles: dia. 50mm and 80mm Internal pipe oriffce: dia. 50mm Jet discharge pipe oriffce: dia. 30mm Jet traverse range (downstream LxW): 600 x 140mm Manometer range: 0-283mm H2O Manometer ffuid: Kerosene (s.g. 0.78)