Heat transfer under multiple slot jets impinging on a permeable moving surface
✍ Scribed by S. Polat; W. J. M. Douglas
- Publisher
- American Institute of Chemical Engineers
- Year
- 1990
- Tongue
- English
- Weight
- 875 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0001-1541
No coin nor oath required. For personal study only.
✦ Synopsis
Local and average heat transfer were measured for a system of multiple jets impinging on a moving permeable surface at which there may be throughflow. Multiple jets were confined by a hood, as is required industrially for thermal efficiency. Exhaust ports located symmetrically between the jet nozzles eliminated crossflow, otherwise a strongly detrimental effect. Impingement surface motion decreases average heat transfer, by 17% at industrially relevant values of the surface motion parameter, M,,. Enhancement of impingement heat flux by throughflow is linearly additive. Expressed as A 3 , this enhancement depends only on the throughflow parameter, Mu,, with ATf/ Mu, = 0.17.
For typical operating conditions, withdrawal as throughflow of only 10% of the jet flow increases mean Nusselt number by over 50%. Industrial design modeling for the potential process of combined impingement and throughflow drying of wet webs such as paper is demonstrated.