高気相体積流束の気泡塔内流れに及ぼす流入気泡径の影響

摘要

中小規模天然ガス田の有効活用を目的として，天然rnガス液体燃料化（GTL: Gas To Liquid）技術の実用化rn研究が進められている．GTL技術における重要工rn程の一つであるFT（Fischer-Tropsch）反応は気泡塔rn型反応装置内で行われ，FT反応塔の設計・経済性評rn価の際には塔内流動状態の把握が必要となる．%Effects of inlet bubble diameter on void and bubble size distributions in poly-dispersed bubbly flow in a rectangular bubble column under high gas volumetric flux conditions are experimentally investigated. Three types of gas distributors are used to form bubbly flows with different inlet bubble diameters at a constant gas flow rate. The conclusions obtained are as follows : (1) the bubble size distribution reaches an equilibrium state at which the birth rate of bubbles belonging to a bubble group due to bubble breakup and coalescence is equal to the death rate at high gas volumetric flux, (2) distributions of void fraction and bubble diameter are not affected by inlet bubble diameters except for the region close to the air diffuser, and ( 3 ) the elevation at which the bubble size distribution reaches the equilibrium state becomes lower as the gas volumetric flux increases.