FORMULATION OF THE BOUNDARY-VALUE PROBLEMS OF LONGITUDINAL MIXING OF PARTICLES IN CIRCULATING FLUIDIZED BEDSYu. S. Teplitskii UDC 533.6 The boundary conditions for the boundary-value problems of longitudinal mixing of particles are substantiated within the framework of circulation and diffusion models. These conditions account for the influence of the bottom fluidized bed on the process of mixing. A. V. Luikov Heat and Mass Transfer Institute, National Academy of Sciences of Belarus, Minsk, Belarus; email: firstname.lastname@example.org. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 76, No. 1, pp. 80-83, January-February, 2003. Original article submitted June 27, 2002.