The Foamed Plastic Layer and the Curvature of Coke Layers

摘要

We have considered the mechanism of formation and subsequent bending of the surface of a separate "cauliflower" and layers in the head part of full-sized coke pieces. In the boundary semicoke layer, just as in a friable solid body, there occurs not only volume shrinkage but also volume thermal expansion, which is responsible for the appearance of the bending moment and the formation of spheres on the head part of coke lumps and also for the curvature of layers in these pieces. We have revealed the versatile role of the foamed gas-saturated plastic layer during the industrial coking process. It may be called a self-regulated (with respect to the temperature gradient) "reactor" of the process of solid-phase polycondensation; it forms the porous structure of coke and contributes to the migration of the vapor-gas phase towards the hot side and to the shear and movement (vertical shrinkage) of the charge being coked under the action of gravitational forces.