Patent ID: 6108935
Filing Date: 2000-08-29
Classification: B01J

Abstract:
In a process for contacting particulate material with a fluid in an annular processing zone, said process comprising:supplying said particulate material for processing in said zone;discharging processed particulate material from said processing zone;generating in said zone a circumferentially directed flow of gas to develop a circumferentially circulating turbulent bed material within said processing zone;an improved processing zone in which particulate material is circulated in a controlled manner to provide a predictable particle flow path both circumferentially of said processing zone and helically of said zone, said improvement comprising:i) directing said flow of fluid to develop said circulating bed with a width between about 2 to 20% of bed outer extremity diameter, an inner bed depth of less than 1% of said bed diameter, and an outer bed depth between about 2 to 5% of said bed diameter;ii) said flow of fluid being directed at an angle relative to processing zone base in the range of about 10.degree. to 45.degree.; andiii) controlling the fluid velocity so that it is greater than the terminal velocity of larger particles at point of impact on the base of the bed and less than the terminal velocity of smaller particles in the superficial space directly above the bed upper surface.