INVESTIGADORES
BUCALA Veronica
artículos
Título:
Cocurrently-Cooled Fixed-Bed Reactors: A Simple Approach to Optimal Cooling Design
Autor/es:
BORIO, DANIEL; BUCALA, VERONICA; OREJAS, JOAQUIN; PORRAS, JOSE
Revista:
AICHE JOURNAL
Editorial:
JOHN WILEY & SONS INC
Referencias:
Lugar: New York; Año: 1989 vol. 35 p. 1899 - 1901
ISSN:
0001-1541
Resumen:
Cocurrently-Cooled Fixed-Bed Reactors: A Simple Approach to Optimal Cooling Design Daniel 0. Borio, Ver6nica Bucalh Joaquin A. Orejas Josh A. Porras Planta Piloto de lngenieria Ouimica 12 de Octobre 1842 8000 Bahia Blanca, Argentina UNS - CONICET Wall-cooled fixed-bed reactors are commonly used in indus- trial plants to carry out highly exothermic reactions. Due to the presence of important heat effects, these units present the well known problems of pronounced maxima in the axial tempera- ture profile (hot spots) and high parametric sensitivity. The safe design of these reactors has been intensively studied during the last decades. Two extensive reviews have recently been published on the subject by PuszyAski et al. (1981) and Froment (1984). Except for the works related to autothermal reactors, most researchers assume that the coolant temperature profile is constant. Only recently has attention been paid to the influence of the coolant-zone design on reactor operation. Luss and Medellin (1972) and Akella and Lee (1983) studied the behavior of countercurrently-cooled nonisothermal tubular reactors, while the cocurrent scheme has been studied by, among others, Degnan and Wei (1979), Soria L6pez et al. (1981), and Hosten and Froment (1986). More complex coolant flow configurations have been studied by Smith and Banchero (1 973) and McGreavy and Dunbobbin (1978). In a recent contribution, Borio et al. (1989) analyzed, com- paratively, three basic cooling schemes: countercurrent, cocur- rent and perfectly mixed coolant. They concluded that for equiv- alent production rates, the cocurrent operation is the one which yields the lowest values for the maximum temperature and para- metric sensitivity, provided an adequate selection for the coolant flow rate can be made. In the present work, following the same guidelines, a simple expression is developed to predict the coolant flow rate value leading to conditions of maximum attainable safety (minimum hot spot and low parametric sensitivity). This analytical tool allows the solution of this optimization problem without the need to resort to a laborious iterative simulation of the unit