Effect of impingement heights on temperature time cooling curve on a run-out table system
To Onah, Ao Odukwe, Sn Ojobor
This research focuses on the development of controlled accelerated top water jet cooling model and water flow to characterize heat extraction on hot steel plates. The methodology undertaken for this research involved design and construction of an experiments using a pilot scale run-out table with stationary plates in MMLE ESUT, Nigeria. Both initial hot plate and water temperatures, control cooling time, controlled temperature ranges of 1600C to 2000C, and 2600C to 3000C, pressure, volumetric flow rates, impingement water jet 0.8mm of 30 number holes, nozzles to surface spacing of 40mm 50mm, 60mm and 70mm, and pipe diameters of 20mm, 25mm, 32mm and 45mm were parameters investigated. Experimentally, three k-type thermocouples were instrumented and installed 9mm from the bottom surface of the plate. Temperature measurements were taken at impingement target on where convectional and evaporation cooling occurred. Conduction heat transfer modelling allowed the calculation of zero temperature. Transient state temperature across the work piece was done by Visual Basic Heat Transfer (VBHT) model. From transient cooling data obtained, studies on effect of impingement height showed that optimum cooling occurred at smaller pipe diameter of 20mm at impingement height of 70mm and bigger pipe diameter of 45mm at impingement height of 40mm at controlled cooling temperature of 3000C because use of the stream wise velocity.
To Onah, Ao Odukwe, Sn Ojobor. Effect of impingement heights on temperature time cooling curve on a run-out table system. International Journal of Multidisciplinary Research and Development, Volume 4, Issue 7, 2017, Pages 97-105