抄録
Heat transfer coefficient and mixing time were measured in an axial-jet mixing vessel equipped with a single or combined nozzle of various diameters.
The equivalent nozzle diameter de for such a nozzle was defined as
de = {(1/2)(4/π)2(pQ3/P)}1/4
where Q and P are total jet flow rate and total power input, respectively. The equivalent nozzle diameter was usable for the correlation of heat transfer coefficient and mixing time for the combined jet nozzle.
The heat transfer coefficient measured was well correlated with nozzle Reynolds number Ren (≡uedeρ/μ) by using the equivalent nozzle diameter, as
hD/κ = 0.27(uedeρ/μ)3/4Pr0.4(μ/μw)0.14
4.2 × 103 < Ren < 5.5 × 104
The mixing time measured was well correlated with the nozzle Reynolds number, based on the correlation method of Hiby et al. The minimum dimensionless mixing time was obtained at Ren = 1.0 × 104–1.3 × 104, and its value satisfied the correlation equation proposed in our previous paper.
