The influence of physicomechanical characteristics of microspherical supporters and dehydrogenation catalysts on their abrasive activity in fluidized bed conditions

Study of factors affecting the erosive wear of equipment for dehydrogenation units in fluidized beds of microspherical chromia-alumina catalysts under industrial operating conditions

“…By alternating the rate of air flow (and thus the rate of particle motion), Eq. (2) obtained in [11] to describe the abrasive activity of microspheri cal catalysts in a fluidized bed can be written as A ≈ Kp m , where A is the abrasive activity, g/m 2 h; p = m av v is the average momentum of catalyst particles, (μg m)/s, where m av is the mass of particles with mean size d av and v is the jet flow rate, m/s; m is an exponent; and K is the coefficient of proportionality, 10 6 /m 3 .…”

“…We recently studied the effect particle size and other physicomechanical properties of particles and materials have on abrasive activity at constant rates of air flow [11]. By alternating the rate of air flow (and thus the rate of particle motion), Eq.…”

“…The attrition of catalysts was studied in a fluidized bed using air as the fluidizing agent on the setup described in [11]. The air was blown into the lower part of the tube through a nozzle at a rate of 4.5-8 m/s.…”

“…The abrasive activity was estimated from the attri tion rate of metal sheet fabricated from grade 3 steel under the action of an aerodisperse flow consisting of catalyst particles and air [11]. The abrasivity of corun dum chips 200-315 μm in size and tested under simi lar conditions was considered to be 100%.…”

“…Relative to IM 2201S, these are characterized by higher activity and selectivity and lower unit consumption of catalyst [2,8,10]. Due to high strength of their grains, how ever, these catalysts have greater abrasive properties [11] and are therefore used primarily in mixtures with IM 2201S rather than individually. Nevertheless, the technology for operating dehydrogenation units with mixtures of catalysts remains insufficiently developed.…”