UA55934A - A process for controlling the burning apparatus thermal conditions - Google Patents

Abstract

A process for controlling the burning apparatus thermal conditions which comprises changing the consumption of fuel being delivered through the high temperature zone burners and temperature stabilization of the gases to be removed. The temperature stabilization of gases to be removed is carried out during the burning carriages movement with the group of cyclones gates opening degree at the ratio 1 : (0 0,5) : (0,25 0,5).

Description

The invention belongs to metallurgy, namely to methods of regulating the thermal regime of firing machines of sintering and sintering factories.

There is a known method of regulating the thermal regime of the firing machine, which includes the extraction of gases from the charge layer and the introduction of liquid refrigerant into the gas stream (Aust. Certificate of the USSR Mo846588, μV s22 V 1/201.

The disadvantage of this method is that the required intensity of liquid supply for cleaning and cooling gases is different and is determined only by the requirements of gas cleaning.

The closest in terms of technical essence to the method that is claimed is the method of regulating the thermal regime of the combustion machine, which includes changing the flow of fuel supplied through the burners of the high-temperature zone and stabilizing the temperature of the gases that are extracted

IAvt. witness USSR Me1486529, MKV C22 B 1/20 |.

The disadvantage of this method is that the stabilization of the temperature of the extracted gases is carried out by changing the intensity of their extraction, which is determined by the temperature difference between the beginning and the end of the technological zone, its length and the speed of the combustion carts. This leads to difficulties in determining the onset of action and absolute changes in the parameters of gas extraction, and, therefore, to the instability of gas penetration and the speed of fuel burning in the charge layer during the movement of the firing carts, to a decrease in pressure and an increase in hydraulic resistance.

The invention is based on the task of improving the method of regulating the thermal regime of the incinerator by dosing the process of extracted gases during the incineration process, which will allow to increase the pressure and reduce the hydraulic resistance, and therefore stabilize the temperature of the extracted gases and improve the technical and economic indicators of the process burning.

The set task is achieved by the fact that in the known method, which includes changing the consumption of fuel supplied through the burners of the high-temperature zone and stabilizing the temperature of the extracted gases, the following exceptions are provided: the stabilization of the temperature of the extracted gases is carried out during the movement of the combustion carts the degree of opening of the shutters of groups of cyclones in the ratio 1: (0 -- 0.5): (0.25 -- 0.5).

There is such a causal connection between the essential features of the invention and the obtained technical result.

Changing the method of regulating the thermal regime of the incinerator according to the invention allows, as the burning zone of solid fuel lowers and the process of decomposition of limestone intensifies with an increase in the amount of gases that are extracted, accordingly, by changing the degree of opening of the dampers of cyclone groups during the movement of the incinerator carts, the amount of gases can be most optimally regulated , which are removed.

To determine the optimal ratio of the degree of opening of the shutters of groups of cyclones, a base period lasting three days, immediately preceding five experimental periods of similar duration, was adopted.

Analysis of the influence of the ratio of the degree of opening of the shutters of cyclone groups 1:0:0, 1:0:0.25, 1:0.25:0.25, 1:0.25:0.5 and 1:0.5:0, 5 on the technical and economic indicators of the firing process reveals that the most optimal is the degree of opening of the dampers of cyclone groups in the ratio 1 : (0 -- 0.5) : (0.25 -- 0.5). At the same time, the highest pressure, the lowest hydraulic resistance and stabilization of the temperature of the extracted gases and the best technical and economic indicators of the burning process were achieved. (Table 1).

The method is carried out as follows.

The prepared mixture of limestone fraction Z - 12 mm and solid fuel fraction Z - 7 mm is laid in a layer of 600 - 6b50 mm across the entire width of the firing machine. During its movement, the layer passes under the furnace, from which high-temperature combustion products are fed to it through an injection burner. Under them by this action, the upper layers are heated and the fuel particles in the mixture are ignited. After passing through the furnace, the dampers on the first group of cyclones are opened at 10095 and the fuel particles are burned as a result of air flowing through the charge layer. Further, the burning process is carried out as the quantity and temperature of the gases that are removed, carried out by opening the shutters of the second and third groups of cyclones sequentially in the ratio of 0 - 5095 and 25 - 5095, according to the first group, in order to stabilize the temperature of the gases that are removed. During the movement of the burning carts, the combustion zone decreases to the grates, which is evidence of the end of the burning process .

A specific example.

The proposed method was tested when calcining limestone on a KM-14 conveyor firing machine in the sintering shop of OJSC ZMK "ZAPORIZHSTAL".

Prepared limestone mixture in the amount of 900 tons/day. and solid fuel in the amount of 90 tons/day. they are placed on firing carts across the entire width with a layer of 65 Ohm at a speed of 0.4 Zm/min. and the fuel contained in it is ignited by combustion products coming from the furnace. After passing through the mine, the shutters on the first group of cyclones are opened at 10095. Next, the firing process is carried out by opening the shutters on the second and third groups of cyclones at 2595 and 5090, respectively, in the first group. At the same time, during the burning process, the temperature of the extracted gases stabilizes at 160°C, the pressure reaches 480 mm H2O, the hydraulic resistance decreases by 10 mm H2O, the production of the burning machine increases to bO0t of lime/add. , and the degree of calcination of limestone up to 8095.

A comparison of the technical and economic indicators of the known method (base period, lasting 30 days) and the proposed method, with a similar duration, are shown in Table 2.

Implementation of the proposed method will make it possible to achieve the most optimal thermal regime of the firing machine, improve the firing quality, increase lime production and, as a result, improve the quality of agglomerate, reduce its cost and coke consumption in blast furnaces.

Table 1

Performance indicators of the burning machine in the basic and test periods

Indexes

Costs taking into account production, t/d.: - limestone 600 630 750 825 900 855 - fuel 60 63 75 82.5 90 85.5

Movement speed, m/min. 0.58 0.52 0.48 0.45 0.43 0.45

Layer height, mm 400 500 550 6oo0 650 5100)

Head, mm of water. Art. 380 390 450 455 480 460

Hydraulic resistance, mm of water Art. 320 300 290 275 240 260

Temperature of gases, "С 70 75 110 135 165 140

The degree of issue limestone, 95 65 66 73 75 81 74

Production, t/d. 400 420 500 550 or 570

Table 2

Technical and economic indicators of the operation of the burning machine in the base period and the period of experimental and industrial tests

Indicators - 1. Costs (incl. production) t/day: - limestone 6oo0 900 - fuel bo 90 2. |Speed. of movement, cars, m/min. 0.58 0.43 3. Layer height, mm 400 650 4. Head, mm water Art. 380 480 5. |Reduction of hydraulic resistance, mm of water. Art. - -80 b. |Temperature of gases that are removed, "C 70 160 7. |Degree of limestone burning, 95 65 80 8. |Lime production, t/day 400 (6308)

Claims (1)

The method of regulating the thermal mode of the incinerator, which includes changing the consumption of fuel supplied through the burners of the high-temperature zone, and stabilizing the temperature of the extracted gases, which is characterized by the fact that the temperature stabilization of the extracted gases is carried out during the movement of the incinerator carriages by the degree of opening dampers of groups of cyclones in the ratio 1 :(0 3 0.5) :(0.25 7 0.5).