To develop efficient vessels with a disperse solid phase, which can be blown-out by the gases that react with the charge and transmit heat (drying of granular materials, regeneration of air in special mounts, gasification of powdered fuel, trapping of the valuable or harmful components of a gas passed through special porous absorbers, etc.), it is necessary to know the distribution of the gas in the layers of the disperse materials [1][2][3]. Experimental methods of determining local gas velocities in granular layers are insufficiently reliable and extremely time-consuming.The simplest problems involving the filtration spread of gas in a layer, and the conditions under which local gushing occurs (a system of jets penetrating a granular layer ) have been solved for the plane and axisymmetric cases [4--6], and these solutions are being successfully employed in the design of chemical reactors with a disperse charge.In a number of cases of practical significance, gas is introduced to these reactors not in the direction of its basic flow in the vessel, but through a lateral port, which is skewed with respect to the vessel's base. The disperse material may be situated directly on the impenetrable base, or on a grid separating it from the base by a drainage slot, which is required for realization of the corresponding production process in some cases, and effectively contributes to hydrodynamic stabilization of the filtration flow of gas over a shorter initial section of the reactor, and markedly reduces head losses associated with the lateral entry of gas to the vessel in other cases.Rational design of a vessel, in which active interaction between the gas and charge is realized in the zone of a hydrodynamically stabilized essentially homogeneous (over the cross section of the vessel) gas flow in the axial direction, is possible when the length of the initial section is known. The height of the vessel may be, among other things, minimized as a result of a limited reduction in the indicated length (for example, for a given height of the gas-entry port above the base of the vessel).The effectiveness of the drainage slot, which may be filled with a "highly permeable" disperse material, is characterized by dimensionless hydraulic-conduction parameter 0 -the ratio of the hydraulic resistance of the layer of disperse material in the vessel to the hydraulic resistance of a drainage slot of the same length: 0 = k20H0(kl0a) -I . If the drainage slot is an empty space between the grid and base, 0 = ~/03(12k10a) -1. Here, kl0 and k20 are the permeabilities, respectively, of the charge in the apparatus and the porous material under the grid, tx is the viscosity of the gas, H 0 is the height of the drainage slot, and a is the width of the vessel.Lyubin et al. [7] analyzed the hydrodynamic stabilization of plane filtration flows in a layer of disperse material with different schemes employed to introduce gas to a vessel through a port of f'mite width with allowance for the influence exerted by a drainage slot in the base of the vesse...
The article presents results of the experimental studies concerning the effect of technological parameters on the process of forming perlite-containing mixtures as well as physical and mechanical properties of granules based on them.
The article deals with the problem of complex processing of technogenic anisotropic materials. The direction of production activity, which requires the creation of special equipment for selective exposure at each stage of the technological process, is determined. A description of the devices of aggregates that have a basic crank-slide scheme of the mechanism for performing various technological functions is presented: grinding, classification, thin and ultrafine grinding, homogenization, agglomeration, etc. A brief description of patent-protected designs of vibro-centrifugal units is given: centrifugal grinding and mixing unit, centrifugal unit with parallel grinding blocks, vibration-centrifugal granulator, vibro-centrifugal unit of combined action. The design features of the vibro-centrifugal unit of combined action intended for complex processing of technogenic fibrous materials in two ways are considered. One of the developed technological options for the implementation of the vibration-centrifugal combined effect on the material is described in detail, in which, according to the single-branch variant, the processes of deagglomeration of technogenic fibrous materials in the first chamber, grinding and mixing of the components of the composite mixture in the second chamber and micro-granulation of the mixture with fiber fillers in the third the camera. The results of the analysis of the kinematic scheme of the basic crank-slide mechanism are presented and a system of equations for determining the position functions of the points of the mechanism links is obtained, the characteristics of speed and power parameters in individual units of the unit are defined. Taking into account the identified advantages of the vibro-centrifugal unit, the directions of its use for complex processing of technogenic materials are determined.
From the standpoint of ensuring the receipt of the recycled bodies for various technological purposes with standard and improved properties applicable in construction, petrochemistry, metallurgy and other areas of material production, recycling in the field of agglomeration of fibrous man-made materials is relevant. The article is devoted to the theoretical studies of the fibrous materials agglomeration characteristics in flat-matrix granulators-extruders with the channels of variable circular cross-section. Taking into account the analysis of the well-known calculation methods and as a result of the theoretical studies, the general regularities have been revealed and the equations have been proposed for determining the equilibrium conditions of a deformable material layer and changes in pressure in the channel, taking into account the effect of the operating device and fiber properties. Analytical dependences and changes in the axial pressure along the channel are obtained reflecting the regularities of the fibrous material movement.
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