SU727699A1 - Method of agglomeration charge heating - Google Patents

Description

The invention relates to the preparation of rudders and concentrates for smelting in ferrous and non-ferrous metallurgy by sintering the charge on an sintering machine. It can be used in the production of pellets and preheating of any wet granular materials.

There is a known method of preheating the charge due to the heat of hot return, which is obtained by treating the aglospace. ka}.

However, the temperature of the charge heated in this way does not exceed 55 ° C directly before sintering, and does not ensure the complete elimination of moisture condensation and the formation of an over-humidification zone, which is theoretically possible only at a charge temperature not lower than 80-82 ° WITH. In addition, the application of this method is usually associated with the deterioration of sanitary and hygienic working conditions,

The closest to the described invention to the technical essence and the achieved result is a method of heating the mixture in the drum by burning gas

over in a drum in layer 2.

However, pilot tests of this method show that it is not sufficiently effective, leads to the exit of drums and heating of the casing to 160-180 ° C. During the drying process, it is possible to distinguish

along with periods of constant and falling drying rate, a very short period of heating the material, if during drying of materials. the heating stage is usually neglected, including almost in the period of the drying speed, then during heating, for example, of the sintering mixture. By sintering the removal of Ylagi from the charge and the destruction of its pellets, it is necessary to heat the pellets to a temperature not higher than the adiabatic saturation temperature (wet thermometer). Thus, in spite of the known laws governing the drying of wet granular materials, the issue of compliance with heating of the charge between the parameters of the coolant and the maximum allowable temperature of the furnace heated without excessive drying did not put

therefore, the ways and means of such heating have not been determined, in particular, in the case of heating with a mixture of DIHXTH

flue gas and in the spirit.

The aim of the invention is to reduce the drying of the wet pelletized mixture, the best preservation of its structure and the reduction of heat consumption for the evaporation of moisture.

  The goal is achieved by heating the charge to a temperature that is at least below the adiabatic saturation temperature (wet thermometer) for a gaseous heat carrier at a given temperature and moisture content.

The finished heat carrier is filtered through a transfer layer (mixing) charge, and the heat carrier temperature is heated, for example, from 200 to 30 ° C and its moisture content is from about 0.02 to 1.0–1.5 or more kg of steam. kg of dry gas; heat carrier suction speed 1.0-1.5 m / s.

The amount of water when pelletizing increase by 10-15% compared with the optimum humidity.

The nature of the influence of the moisture content of the coolant on the conditions for heating the mixture as well as the effect of its temperature follows from the balance equation for the evaporation of moisture during convective drying of the wet granular material.

When burning, for example, Bukhara gas with increasing temperature. the heat carrier from 300 to its moisture content also increases from 0.026 to about 0.080 kg of steam per kg of dry gas, therefore t “increases under the influence of both factors simultaneously. For a heat carrier of one temperature, for example, a 600 ° Cj increase in moisture content from 0.046 to 0.6 kg / kg provides an increase in the adiabatic saturation temperature (wet thermometer) from practically 65-67 to 82-84 ° C.

This method of heating the pouring bed mixture (wet granular material) is tested in laboratory conditions at the sintering mixtures of different composition.

The table shows the individual results of these tests on a lateral installation for heating the sintering mixture in a drum-pelleter with a diameter of 0.8, 55 m.

The results of individual experiments in the table show that for heat carriers of a certain temperature (and moisture content, respectively), an increase in the duration of heating beyond a certain limit leads to a noticeable drying of the charge, which is detected by the release of steam, and then fine dust, especially noticeable for iron ore < / RTI > as in this case, the loss of moisture more affects the strength of the charge granules. Increasing the temperature and filtration rate of the coolant intensifies the heating process. ,

According to more than one hundred experiments, a necessary and sufficient factor for raising the final temperature of a heated mixture without excessive drying from 55-50 to 68-70 Cl is an increase in the temperature of the heat carrier from 300 to 700 ° C, and in all cases the temperature is heated optimally. charge were below the approximate design temperatures of the wet thermometer for the heat carrier of the given parameters.

The proposed method can be carried out using Jno6oro of a known device, which allows to sufficiently evenly distribute the coolant in the pouring charge layer or, in general, in a layer of mixing wet granulated material, for example, with a distribution device that connects the coolant collector with outlets and multislip diffusers on them, immersed in a layer of charge that is poured in a drum-pelletized mixture.

0.81 520 BUT

0.81 500 100

fluxed 2.10 1.00 400 90

(Iihta

,, 24 kg,

.V POD29, 3 25.8 24.6 16 60 0.914 0.880 dried,

  few

25.0 27.0 26.4 20 48 0.905 0,

, ---- - 25.9 kg

dried a little but. t t

21.4 9.03 7.66 14 59 1.74 1.84

dried out after

2 min dust

Claims (2)

Claim 1. Method of heating the sinter blend to 93-97 0 with a mixture of flue gases with air, which is different from that with the aim of reducing the drying of wet pelleted to better preserve its structure during sintering and to reduce heat consumption for evaporation of moisture during heating, preheating to temperature below the adiabatic temperature for heat. : K - --v--: .., - ,. .. ,, .. ,,, -.--: - ----; d1 "----.-- - -..-.-.-- -, ..-.... . ...: 7276998 of a given temperature and moisture 3. The method according to PP, 1 and 2, is about 1 ton of content. Considering that amount 2. The method according to claim 1, about 1 and 2 o of water with pelletizing is increased by u and, with that, 410, with a view to an intensity of 10–15% compared with optimal heating, temperature and humidity, tours of the heated mixture and uniform heat e}, heat temperature. Information sources, heat carrier within 200- 1300 ° C, taken into account in the examination of a moisture content of 0.02-1 kg of steam / kg 1. Wegman EF Theory and technology losuhogo gas and sucked-gi teplonosi agglomeration. M, Metallurgists, tel through a mixing layer- “1976, p. 22-40. heated by the mixture at a speed of 1.0 2. USSR author's certificate 1,5 m / s. № 116628, cl. From 22 to 1/16, 16,12.57.