Scaling of catalytic cracking fluidized bed downer reactor based on CFD simulations-Part II: effect of reactor scale.

The practical realization of the scaling up of gas-solid multiphase flow reactors with chemical reactions is hindered by chaotic flow behaviors and complex heat and mass transfers in the reactor. In addition, a law to scale up complex reaction mechanisms in multiphase flow systems has been rarely proposed in the existing literature. Thus, this study aims to investigate the scaling up of the catalytic cracking fluidized bed downer reactor based on the similitude method of chemical reaction performance.

Scaling of a catalytic cracking fluidized bed downer reactor based on computational fluid dynamics simulations.

Circulating fluidized bed downer reactors (downer reactors) exhibit good heat and mass transfer, and the flow behavior approaches the ideal plug flow. This reactor is superior for catalytic cracking reactions in which the intermediate is the desired product. However, the hydrodynamic behavior and reactor performance have mostly been investigated in small-scale or laboratory-scale reactors.

A new species of Tetraphyllidean (Onchobothriidae) cestode from the brown-banded bambooshark Chiloscyllium punctatum (Elasmobranchii: Hemiscylliidae).

Yorkeria chonburiensis n. sp. (Tetraphyllidea: Onchobothriidae) is described from the spiral intestine of a specimen of the brownbanded bamboo shark, Chiloscyllium punctatum, collected from the Gulf of Thailand, Chon Buri Province, Thailand.