SU691656A1 - Installation for drying granular materials - Google Patents

Description

(54) INSTALLATION FOR DRYING GRAINS OF MATERIALS

The invention relates to a plant for drying in a suspended state wet granular materials, for example, coal preparation products, and can be used in coal, chemical and other industries. Known installation CL drying of dispersed materials. containing yortically located Venturi pipe connected to the separator and equipped with a loading nozzle, which is adjacent to the neck of the Venturi pipe tlj. The use of these plants for drying polydisperse granular materials (for example, coal concentrates), including grains larger than 13 mm and because of the increase in energy costs for the vertical movement of the solid phase, is economically disadvantageous. Also known are installations for drying granular materials containing a horizontal pipe, a Venturi with a loading pipe connected to a precipitator - a cyclone separator 2. In these plants and trucks, the granular materials flow during the drying process at relatively low energy costs. These installations by technical solutions are closest to that described. However, their intensity of heat and mass transfer processes is lower than that of the units (1, for the following reasons: - a lower degree of aerodynamic braking of the solid phase during horizontal mieBMO transport as compared to movement in a vertical pneumatic flow in the pipe, respectively, causes a lower relative speed of phase sliding in the device - an additional reduction of this value causes an accepted constructive solution — the junction of the loading nozzle to the throat of the Venturi pipe, where the heat transfer medium moves a speed lower than a subsequent downstream gas suspension uchastkeg but the efficiency of the drying process determines the intensity of the aerial (ynamic audio particles flowing around it during the initial moment of contact between the phases when the maximum driving force of heat and mass transfer;

.-; ttfe ensures uniform distribution of the material / injected under the action of its own web over the circular section of the cylindrical drying channel;

 the bottom wall of the pipe diffuser with, the venturi undergoes an increased

abrasive and% of the solid material that move along the descending trajectory of m simultaneously in the upper part of the diffuser (above the axis of symmetry Q) there is a gas flow with a lower concentration of suspended material;

 - cyclone separator for separation of gas suspension is unreliable when catching vagshi grains of dried material possessing greater microhardness and abrasiveness (for example, anthracite), so active in contact with the walls of the separator - .. solid particles pressing in their . surface, under the action of centrifugal force Scratch and intensively wear-; Shiv yutapparat. The purpose of the present invention is to eliminate these disadvantages; kok and increase of profitability of installation. :

 . This goal is achieved by the fact that in a plant for drying granular 30 Gs: Series containing a horizontal venturi tube connected to a precipitator to separate

 Gas suspension and feed inlet,

The loading nozzle is connected .. 35 to the Venturi pipe in the neck area, and in front of the loading pipe in the K6F fusor of the Venturi pipe there is a 6-hole gas grill, and the Venturi pipe diffuser 40 is made with an oblique cut

 inside osahsitel. In the area of the neck of the Denturi tube, an even distribution of the solid particles over the entire cross section is practically necessary. This eliminates the peripheral breakthrough of the heat transfer fluid, bypassing the load flow. The presence of the Venturi neck of the gas distribution grid allows additional to intensify the flow of npojie cca dryc.

You interact with the loaded material of the heat carrier jets flowing from the nozzle openings of the gas distribution grid at high speed I Kpme, the Venturi tube diffuser is made asymmetrical - with a horizontal upper and an inclined bottom wall and an oblique cut in

: jetting agent. The slope 60 of the lower wall of the diffuser is chosen in such a way that for the source material, when the pneumatic transport mode is adopted, the contact of solid particles, which are 65

travel in descending paths with the diffuser diishe. During gravitational sedimentation in a jet precipitator, the solid particles of the dried material move at a lower speed than in the cyclone separator, and their contact with the walls of the precipitator is not complicated by the specific pressure normal to the surface of the apparatus. Such design solutions will reduce the amount of abrasive wear.

FIG. 1 schematically shows a general view of the installation described; in fig. 2 — one of the embodiments of the gas distribution grid; in fig. 3 is another of hers.

The plant for drying granular materials contains a heat generator 1, a horizontal ventural tube of rectangular cross section, with schu1111e from a confuser 2, a neck 3 and a diffuser 4; gas distribution valve 5, loading pipe 6, jet precipitator 7 with outlet window 8 gdz and windows 9 for the material collected. A gas distribution grid 5 vertically installed in the orifices 3 with a small living section is made in the form of a ceramic plate (Fig. 2), equipped with conical holes 10, decreasing in the course of the coolant flow, or horizontally arranged metal trapezoidal section 11 is assembled (Fig. 3 ).

The installation works as follows ..

The heat carrier prepared in the heat generator 1 flows through the confuser 2 and then, entering the throats of 3 Venturi pipes, runs out from you-. a low velocity from the nozzle holes 10 or slits formed by the rod 11. At the same time, the heat carrier splits into jets, which, due to the high velocity heads, are low-pressure zones. A gas rushes from these inter-jet spaces of the neck 3 to these zones. causes a drop in pressure in the latter. Under the action of its own weight, the Material is introduced through the loading nozzle 6 into the neck 3. Solid particles trapped in the inter-jet space, then move into the zone of action of the jet, since there the pressure is lower. All the material is involved in intensive movement and agitation, which improves the uniformity of gas distribution, and the solid particles of the material acquire sufficient speed for stable horizontal pneumatic conveying. The inertia of particles in contact with high-speed devices causes a significant difference in the velocity heat.