SU1478009A2 - Pneumatic drier for polydisperse materials - Google Patents

Abstract

The invention may be used in the chemical, food, and chemical-pharmaceutical industries. The purpose of the invention is to improve the quality and uniformity of drying. On the inner side of each half-turn 4 of the spiral partition of the pneumatic dryer at a distance of 1/8 - 1/4 of its length, before the slot gap 5 of the partition, it is additionally mounted to move along the half-turn 4 flow 7 swirler. The swirler 7 is made in the form of a parabola branch, the console end of which is bent away from the corresponding half-turn 4 by a distance equal to 1/10 - 1/5 of the width of the spiral channel. The design of the air dryer allows you to adjust the drying exposure, increase the drying depth by allowing the residence time of the various fractions in the cyclone to be controlled. 2 Il.

Description

FIG. 2

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The invention relates to a technique for drying dispersed materials, can be used in chemical, food, chemical and pharmaceutical, and other related industries and is an improvement of the pneumatic dryer according to the author. St. No. 769255.

The purpose of the invention is to improve the quality and uniformity by adjusting the drying exposure.

Fig. 1 shows a pneumogram for polydisperse materials, a slit; in fig. 2 shows a section A-A in FIG.

Air blowers contain a supporting flat bottom 1, on which spiral channel 2 is formed, formed by spiral partition 3, having 4 slit gaps 5 on each half-roller, adjustable by means of hinged shutters 6, swirlers 7 flow in the form of a parabola branch, having the ability to move along the inner sides of the semi-turn of the spiral partition 3 and located at a distance of 1 / 8-1 / 4 of the length of the semi-turn with slit gaps 5, cover 8, fittings 9 and 10 for introducing the material and heat carrier, vortex chamber 11 formed by the inner helical baffle surfaces 3, output in the form of a cyclone 12 arranged on pnevmosushilki axis and cyclone 13 O coarse fraction.

Moreover, the cantilever end of each branch of the parabola is bent from the corresponding half turn to a distance of 1/10 1/5 of the width of the spiral channel.

Air dryer works as follows.

The original wet polydisperse material through the nozzle 9 is fed into the intermediate coil of the spiral channel

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reducing the hydraulic resistance of the apparatus and maintaining a stable hydrodynamic structure of the gas suspension flow in it. The cantilever channel of each branch is bent from the half-branch of the partition within 1 / 10-1 / 5 of the channel width, since at smaller values the effect of rejecting material particles is insignificant and the degree of separation is not provided, and at large values the hydraulic resistance of the apparatus increases dramatically. abrasion of the material being dried and erosion of the channel walls.

Centrifugal forces have a stronger effect on particles with a larger mass, i.e. larger and wetter, so they reach again the inner wall of the spiral channel 2 faster than small and dry ones. The distance between the swirlers 7 of the flow and the slit gaps 5 is chosen within 1 / 8-1 / 4 of the arc length of the corresponding half-turn depending on the speed of the transporting agent, the width of the spiral channel, the fractional composition of the material being dried, its humidity and so on. further, in such a way that the slit gaps of the wall of the spiral channel reach only particles of greater mass, i.e. large and wet, which will be through the gap gaps fall into the previous turn of the spiral channel. Particles with a smaller mass, i.e. smaller and dry reach again the inner wall of the spiral channel already behind the slit gaps and do not fall into them. The distance between the swirlers 7 and the slit gaps 5 is chosen to be 1 / 8-1 / 4 the length of the corresponding half-turn.

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2, where it is picked up by the flow of heat from the helix, since, in the case of receiving the carrier, the distance through this fitting is less than 1/8 of the length-10, and is transported by it from the periphery of the half-turn center of the dryer, which ensures the drying process. At each half-turn of the spiral channel 2, particles of solid material moving as a result of the impact of centrifugal force on the inner wall of the channel, are thrown off by swirlers 7 of the flow to

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Even the largest and wet particles and the residence time of all the dryer fractions in the same way will not have time to reach the gap gaps. If this distance is chosen to be greater than 1/4 of the length, all particles reach the inner wall of the channel to the slit gaps, which leads to falling into the previous turn of small particles and their overheating.

the internal wall of the channel, the Flow Swirlers 7 are made in the form of a parabola branch, since the rotating gas flow has a parabolic profile near the channel wall

spirals, since, if this distance is taken to be less than 1/8 of the half-turn length, the inner wall is spi

Even the largest and wet particles and the residence time of all the dryer fractions in the same way will not have time to reach the gap gaps. If this distance is chosen to be greater than 1/4 of the length, all particles reach the inner wall of the channel to the slit gaps, which leads to falling into the previous turn of small particles and their overheating.

The fine fraction is transported in a vortex chamber 11 axial cyclo

Claims (1)

Claim Pneumatic dryer for polydisperse materials according to ed. St., No. 769255, characterized in that, in order to improve the quality and uniformity by adjusting the exposure of drying, on the inner side of each half-turn of the spiral partition at a distance equal to 1 / 8-1 / 4 of its length, in front of the gap gap is additionally installed with the possibility moving along a half-turn, a flow swirl made in the form of a parabola branch, the cantilever end of which is bent from the corresponding half-turn by a distance equal to 1 / 10-1 / 5 of the width of the spiral channel.