1984 Ind. Eng. Chem. Res., Vol. 29, No. 9, 1990
T , = temperature of air entering the core, K T3 = temperature of air leaving the core, K T4 = temperature of air leaving the exchanger, K U = overall heat-transfer coefficient from one fluid to the other, W/(m2-K) w = mass rate of flow, kg/s t = distance along the heated surface, m Z = =N(2z/l) Greek Symbols
= h,/U b = [a(2+ t = ( T 2- T 1 ) / ( T 3 T2),thermal effectiveness 6 = angular coordinate, rad v = kinematic viscosity of fluid, m2/s
CY
Subscripts 1 = on wall-1
2 = on wall-2 c = at inner surface of spiral (at core) cy1 = for a cylindrical surface e = exiting flat = for a flat surface i = entering lm = logarithmic-mean value max = maximum value min = minimum value o = a t outer surface of spiral (at outside of exchanger) opt = optimal value p = index of a turn for entering fluid p + 1 = index of adjacent inner turn for exiting fluid p - 1 = index of adjacent outer turn for exiting fluid q + 1 = index of outer wall for turn p q - 1 = index of inner wall for turn p Registry No. Al, 7429-90-5;Pt, 7440-06-4.
Literature Cited Baird, M. H. I.; McCrae, W.; Rumford, F.; Slesser, C. G. M. Some Considerations on Heat Transfer in Spiral Plate Heat Exchangers. Chem. Eng. Sci. 1957, 7, 112-115. Buonopane, R. A.; Troupe, R. A. Analytical and Experimental Studies in a Spiral Heat Exchanger. Fourth Proc. Znt. Heat
Transfer Conf. (Paris-Versailles) 1970, I (Paper HE 2.5), 1-11. Cheng, K. C.; Akiyama, M. Laminar Forced Convection Heat Transfer in Curved Rectangular Channels. Int. J. Heat Mass Transfer 1970, 13, 471-490. Choudhury, K.; Linkmeyer, H.; Bassiouny, K.; Martin, H. Analytical Studies on the Temperature Distribution in Spiral Plate Heat Exchangers: Straightforward Design Formulae for Efficiency and Mean Temperature Difference. Chem. Eng. Process 1985, 19, 183-190. Churchill, S. W.; Tepper, P. The Characteristics of a Single-Fluid, Double- or Triple-Pass Heat Exchanger and Combustor for LowHeating-Value Gases. Znd. Eng. Chem. Process Des. Deu. 1985, 24, 542-550. Cieslinski, P. J.; Bes, T. Analytical Heat Transfer Studies in a Spiral Plate Exchanger. Proc. XVIth Znt. Congr. Refrig. (Paris) 1983, IZ (Paper B.1-198), 449-454. Coons, K. W.; Hargis, A. M.; Hewes, P. Q.;Weems, F. T. Spiral Heat Exchanger-Heat-Transfer Characteristics. Chem. Eng. Prog. 1947, 43, 405-414. Jones, A. R.; Lloyd, S. A.; Weinberg, F. J. Combustion in Heat Exchangers. Proc. R. SOC.London, Ser. A 1978,360,97-115. Langmuir, I. Convection and Conduction of Heat in Gases. Phys. Reo. 1912, 34, 401. Martin, H.; Choudhury, K.; Linkmeyer, H.; Bassiouny, M. K. Straightforward Design Formulae for Efficiency and Mean Temperature Difference in Spiral Plate Heat Exchangers. Proc. Eighth Znt. Heat Transfer Conf. (San Francisco); Hemisphere Publishing: Washington, DC, 1986; Vol. VI, pp 2793-2797. Minton, P. Designing Spiral-Plate Exchangers. Chem. Eng. Prog. 1970, 77, 103-112.Morimoto. E.: Hotta. K. Studv of the Geometric Structure and Heat Transfer Characteristics of a Spiral Plate Heat Exchanger. Nippon Kikai Gakkai Ronbunshu 1986,52,926-933; English translation Heat Transfer-Jpn. Res. 1988, 17, 53-71. Tangri, N. N.; Jayaraman, R. Heat Transfer Studies on a Spiral Plate Heat Exchanger. Trans. Inst. Chem. Eng. 1962, 40, 161-168. Winters, K. A Bifurcation Study of Laminar Flow in a Curved Tube of Rectangular Cross-Section. J . Fluid Mech. 1987,180,343-369. Zaleski, T.; Lachowski, A. Znzymieria Chemiczna i Procesowa 1984, 5,559-577; English translation Unsteady Temperature Profiles in Parallel-Flow Spiral Heat Exchangers. Znt. Chem. Eng. 1987,27, 556-565. Received for review July 3, 1989 Revised manuscript received March 29, 1990 Accepted April 4, 1990
ADDITIONS AND CORRECTIONS Calcium Oxide Sintering in Atmospheres Containing Water and Carbon Dioxide [Volume 28, Number 4, Page 4931. Robert H. Borgwardt Page 497. T h e second term on t h e right-hand side of eqs 7 a n d 8 should be preceded by In and should be enclosed in brackets. T h e correct equations are In 7 H l O = 0.002622"+ In [(ln P H l o - 1.39)/11.1] (7) In yCo2= 0.0034T
+ In [(ln Pco2- 1.948)/44.9]
(8)
T h e error is typographical only a n d does not affect t h e calculated results presented in t h e article.
