SU771163A1 - Tuyere of blast furnace - Google Patents

Description

(54) FURMA DOMAIN FURNACE

one

The invention relates to the field of ferrous metallurgy, in particular to the equipment of blast furnaces.

Known tuyere of a blast furnace, for increasing resistance, which is used intensive cooling for the combination of non-isothermal fins of the heat transfer surface, underheating and high speed of the cooling fluid at a relatively low O its consumption 1.

However, in the known lance, the elements of the heat-transfer surface are not sufficiently cooled. For example, ep-15 is more intensively cooled, while the lateral surface has no fins and is cooled without proper organization of water flow.

Closest to the invention 20 of the technical essence and the achieved result is a lance of a home furnace, including a housing with edges on the cooling surface, a hollow annular partition 25 with fixatives tangentially directed nozzles in the nose part 2.

The design flaw of this tuyere is that 30

the height of the narrow gap for the passage of water is constant everywhere. As a result, the cooling intensity of the nasal and lateral surfaces is the same. Meanwhile, it is known that the nasal part of the lance works under the most severe conditions, where the local thermal stress is great when in contact with liquid iron. Another structural disadvantage of the tuyere is the longitudinal direction of the water flow relative to the ribs on the cooled surface, which reduces the cooling efficiency. The purpose of the invention is to increase the service life due to the intensification of cooling, mainly its nose.

The goal is achieved by the fact that the gap between the hollow annular septum and the nose part is 1 / 5-1 / 8 of the total length of the body, while the latches in the nasal part of the partition have a ratio between the length and width of 5-10 and are directed along the axis of the tuyere, and the ribs directed across the body of the shell.

The specified height of the gap between the partition and the front wall of the tuyere is selected based on the following.

The long-lasting durability of the tuyeres of the proposed construction can be ensured with a water consumption for cooling the tuyere in the range from 2 to 3–3.5 l / s. Since an increase in the rate of flow of water above 0.4 m / s is impractical, the height of the cavity being cooled was calculated from the condition that this velocity was preserved.

The cross-sectional area of the cavity is determined from the expression:

s- a

where Q is the cooling water flow

cm Vc;

n is the number of nozzles; V - water velocity, equal to 40 cm / s. With n 2 and Q 2000

aooo

3

2 -40

With a cavity width at the front wall of a typical air tuyere, equal to 5 cm, its height is 5 cm or 1/8 of the total length (40 cm) of the tuyere body. With an increase in water consumption up to 3-3.5 l / s, the height of the cavity with n 2 is equal to 8 cm or 1/5 of the height of the tuyere body. For p 3, the specified height will be close to its lower limit.

Increasing the height of the cavity above 1/5 of the height of the body will lead to a decrease in the speed of movement of the water, and consequently, to a deterioration in the cooling of the tuyere. Reducing the height of the cavity to a value of less than 1/8 of the height of the body will result in excessive hydraulic losses during the movement of water.

To ensure the rotation of the water flow from the annular chamber in the direction of the longitudinal axis of the tuyere with its subsequent stabilization, it is necessary to ensure a ratio of the length of the partition to the height of the gap not less than 510. Increasing this ratio to higher values is undesirable, as it will lead to an increase in hydraulic losses.

In the tuyere, all the cooling water through tangentially directed nozzles at high speed first enters the front toroidal cavity formed by a hollow annular partition and the nose part of the tuyere, where the ribbed nose intensively cools along the annular path. From the front cavity, water with a large underheating and a sufficiently high speed enters the narrow channels between the hollow annular partition and the inner and outer walls of the tuyere, which are made of silver, to cool them. The flow of water at the same time, as in the nose, is directed across the ribs.

Thus, the design allows, without increasing the flow rate of cooling water, to intensify the cooling of the tuyere, especially its most heat-stressed forebody, to make it more resistant to the impact.

High temperatures in contact with liquid iron and abrasive charge.

Figure 1 shows the proposed urma; figure 2 is the same, section aa and figure 1.

The lance consists of body 1, bridging to flange 2, hollow annular partition 3, which, with lanes 4, constitutes a closed cavity and is fixed relative to the body of the lance fixtures 5. The side surface of the urma has ribs directed perpendicularly and the nose . This combination of scrubbed surfaces is caused by the fact that the nose of the tuyere is made integral by stamping with the obligatory direction of the ribs along the inner surface, which ensures free removal of the internal stamp after the stamping operation is completed. The transverse direction of the ribbing of the side part of the lance of the tuyere is determined by the direction of water flow along the forming walls after it leaves the front cavity. the cooling water is supplied to the pipe 6, passing through the flange 4 and communicating with the cavity of the annular partition Z. In the front part of this partition there are several openings with tangent directional nozzles 7 extending into the front cavity 8. Narrow channels 9 between the hollow annular partition and the body of the tuyere They serve to drain water from the front cavity and simultaneously cool the side walls of the housing. Through the holes 10 in the flange 4, the water enters the rear cavity 11 and the outlet 12.

During the operation of the tuyere, the cooling water through the pipe 6 and the tangentially directed nozzles 7 is supplied to the front cavity 8, where it moves along a circular path across the direction of the fins with great speed. From the front cavity, water rises along the narrow channels 9, cooling the side walls of the tuyere body. The transverse direction of the flow relative to the ribs in the lower part of the side surface is achieved with the help of thin clamps 5 attached to the hollow annular partition 3 so that their direction approximately coincides with the longitudinal axis. The height of the retainers is 5-10 times the width of the gap between the hollow annular partition and the side wall of the tuyere, which is necessary to turn the rotational motion of water in the front cavity into a translational one when the side surface is cooled. The use of longer clamps will increase the resistance of the moving water. From channels 9 through

The holes 10 in the flange 4 water enters the rear cavity 11 and then into the pipe. For a more uniform flow of water into the cavity 11 through the all holes 10, the latter have an area of living cross-section, gradually increasing as they are removed from the discharge pipe.

The design of the proposed tuyere permits reliable cooling of both its most heat-stressed nose part and relatively less heat-stressed side surface without a general increase in water consumption, which increases the service life of the tuyere.

invention formula

1. A lance of a blast furnace, comprising a housing with ribs on a cooled surface, a hollow annular partition with clamps and tangentially directed nozzles in the nose, characterized in that, in order to increase its service life, Em 1 / 5-1 / 8 of the total length of the body, while the locking tabs in the nose of the hollow annular septum have a ratio between the length and width of 5-10 and are directed along the axis of the tuyere.

0 2. Tuyere POP.1, characterized in that the ribs are directed across forming hulls.

Sources of information taken into account in the examination

S 1. Patent of England 868384, cl. From 21 to 7/16, 1962.

2. Patent of England W 1274074, cl. From 21 to 7/16, 1971.

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Claims (1)

Claim 1. The tuyere of a blast furnace containing a body with ribs on a cooled surface, a hollow annular partition with retainers and tangentially directed nozzles in the nose, characterized in that, in order to increase its service life, the gap between the hollow annular partition and the nose of the tuyere is 1 / 5-1 / 8 of the total length of the housing, while the tabs in the bow of the hollow annular septum have a ratio between the length and width of 5-10 and are directed along the axis of the lance. 1® 2. The lance according to claim 1, characterized in that the ribs are directed across the generatrix of the housing.