The multijet facility is a scaled model of a fast cooling system used in galvanizing lines. It consists of two settling chambers with a set of slot nozzles. The slot arrangement can be adjusted to investigate the effect of geometrical parameters such as the nozzle spacing, the nozzle emergence and the impinging angle.
More than 50 nozzles are available to cover the whole range of each parameter. The translation of the multijet systems allows changing the stand-off distance. A ventilator delivers a nominal flow rate of 5 m3/s at a relative pressure of 10000 Pa, which ensures a maximal slot velocity of 100 m/s. The facility has been designed to handle both cooling tests and vibrations tests.
For the cooling tests, only one settling chamber is in operation and the air jets impact on a vertical flat plate of 1.7 m long and 0.27 m wide, uniformly heated on one side by electrical means. The heated surface is exposed to the impinging flow while an infrared camera scans the other side. For the vibrations tests, the two settling chambers are used and the air jets impact on a rigid plate modeling an element of the metal strip. Its connections to a fixed frame reproduce the elasticity of the remaining part of the strip. Dedicated displacement sensors measure the oscillations of the sectional model.