SU932155A1 - Method of drying black carbon pellets - Google Patents

Description

one

The invention relates to a technique for drying granulated materials in a fluidized bed and can be used in the petrochemical and other industries.

A two-stage method of drying soot granules is known by drying them in a fluidized bed and subsequent drying with simultaneous compaction and grinding of the granules in a rotating drum.

The disadvantages of this method are the difficulty of regulating the process and the significant capital costs of implementing the method.

The closest to the proposed technical essence and the achieved result is a method of drying dispersed materials by loading them into the fluidized bed created by the main coolant flow supplied from the bottom, side feeding the additional coolant flow into the layer and unloading the oil 2.

A disadvantage of the known method is the low efficiency of the effect of the additional coolant flow on the compaction and grinding processes in the case of drying the soot granules, since this stream is fed into the loading zone of the wet granules.

The purpose of the invention is to intensify the drying process.

The goal is achieved by the fact that the additional flow of heat-transfer agent is twisted and fed, in the amount of 10% of the amount of the main heat-transfer agent, in the discharge zone of the granules.

In addition, the pressure of the additional coolant flow is maintained at 10 to 30 times the pressure of the main flow.

The degree or intensity of the twist (the ratio of the axial and angular momentum of the quantities of motion) of the additional coolant flow is assumed to be 0.6-5; 0. With degree

spins of less than 0.6 are small, the soot granules are recycled inside the vortex, and the flow turbulence is also small, which reduces the degree of mixing of the coolant with the granules and the intensity of heat and mass transfer. Increasing the degree of twist more than 5.0 is irrational due to increased energy costs.

Under limited conditions, the flow of additional coolant flows, the vortex two can last generate acoustic oscillations with a frequency of 250-500 Hz, which contribute to the removal of moisture from the granules.

Figure 1 shows schematically an apparatus for drying soot granules according to the proposed method; in fig. 2 section A-A on (lb.1.

The apparatus for drying soot granules contains a drying chamber 1, gas distribution grid 2, nozzles for inlet 3 and outlet of the heat carrier, loading 5 unloading 6 nozzles, a pipeline 7 dp supplying additional heat carrier flow and rotary vane swirlers. 8 it is possible

by installing them at the exit of the impeller, the turbine and the azoturbine engine (not shown).

The device works as follows.

Soot granules with moisture up to 501 through pipe 5 are fed into the drying chamber 1. At the same time, gaseous coolant is fed through pipe 3, which passes through the openings of the gas distribution grid 2 and maintains the granules in a fluidized state. The heat transfer fluid is discharged through a nozzle.

1-2 minutes before the pellets leave the chamber 1, they are subjected in the unloading zone to the effect of an additional heat carrier flow swirled by swirlers 8c with a twist intensity of 0.6-5.0. In this case, an additional drying of the granules is carried out with simultaneous compaction and the removal of the granules.

The finished granules with a moisture content of 0.5% are removed from chamber 1 through the nozzle 6.

The table shows the results of experiments on the drying of soot granules by the proposed method.

The flow rate of the main flow of the coolant supplied under the layer of granules

The pressure of the main flow heat carrier supplied under a layer of granules, kPa

Additional gas flow rate, nm / h

Pressure of additional gas flow, kPa

Heat carrier temperature, С

Spin intensity additional flow0,6 3,0

6600

660

0 610

52

600

5.0

Humidity of the granules after drying

Qualitative characteristics of goanul after drying:

a) bulk density, g / 1000 cm

b) single strength of granules, kg

c) mass strength of granules, kg

d) fractional composition, - and

The proposed method allows, by creating a vortex motion of the additional coolant flow in the discharge zone of the pellets, to increase productivity by.

Claims (2)

1. The method of drying soot granules by loading them into the fluidized bed, creating the main coolant flow supplied from the bottom, side feeding the additional coolant flow to the layer and unloading the granules, so that the purpose of intensifying the drying process and increasing the continuation of the table Oh, it 0.5 0.6 372 366 20 9 22 23 3.0 m They are economical, the cooling flow of heat carrier is twisted and served in the unloading zone of granules in an amount of 10% of the amount of the main heating medium. 2. The method of Claim 1 is different from and vi so that the additional pressure of the heat transfer fluid is maintained at 10 to 30 times the pressure of the main flow. Sources of information taken into account in the examination 1. US patent f, cl. publish 197. 2. USSR author's certificate ff 573693, cl. F 26 B 17/10, 1375.