RU2138560C1 - Slide valve of blast-furnace air heater - Google Patents

Abstract

FIELD: metallurgy. SUBSTANCE: slide valve has lined casing with cover and cooled lined hollow disk with shell provided with two round sides. Shell is positioned in cooling cavity defined by curved side guide, which is made of inclined separating walls and tubular insert. Insert is positioned in disk cavity part enclosed between shell, sides and guide in equally spaced relation to disk inner surface. Tubular insert cavity is connected at its top end with coolant supply branch pipe and is communicated at its bottom end with disk cavity. Lower end of tubular insert is provided with narrowed portion with inner diameter of lower end being equal to 0.8-0.9 of inner diameter of upper end. Lower end of curved guide is bent inward of disk at an angle of 25-30 deg to tangent to its path and extends beyond lower edge of tubular insert by distance equal to 0.2-0.25 of its length. EFFECT: improved cooling conditions for disk, reduced probability of disk burning and increased service life of slide valve. 5 dwg

Description

 The invention relates to the field of ferrous metallurgy and for the equipment of air heaters of blast furnaces, in particular hot blast valves.

 Known gate valve of a blast furnace heater (see ed. Certificate N 775134, class C 21 B 9/12, application form 10.07.78, publ. 30.10.80), comprising a lined housing with a cover and a cooled lined hollow disk, consisting of shells with two round sidewalls located in the cooling cavity of a curved side guide for supplying refrigerant to the lower part of the cavity and inclined dividing partitions. Inclined dividing walls are installed in relation to the curved guide and to the shell with the formation of a loop-shaped cooling channel. To accelerate the flow of refrigerant in the lower part of the cavity, a curved side guide is close to the shell.

 The disadvantage of this valve is the insufficient cooling rate of the lateral non-lined walls of the disk in its lower part due to the fact that the flow rate during narrowing of the channel formed by a curved guide increases, as a rule, only in the middle part of the channel, and remains the same at the side walls. In addition, the possibility of clogging by deposits of mechanical suspensions of the zone bounded by two lower dividing walls and a side rail is not ruled out.

 Of the known closest in technical essence (prototype) is the slide valve of the blast furnace heater described in Russian patent N 2005795, class. C 21 B 9/12, claimed 06/22/92, publ. 1/15/94.

 This damper valve of a blast furnace heater comprises a lined case with a lid and a cooled lined hollow disk, consisting of a shell with two round sidewalls, located in the cooling cavity of a curved side guide for supplying refrigerant to the lower part of the cavity, inclined separation walls and a tubular insert located in part of the cavity a disk enclosed between a shell, sidewalls and a guide. The insert is equidistant from the inner surface of the disk, and its length is 0.6 - 0.8 of the length of the curved guide. The upper end of the insert is spaced from the upper end of the guide at a distance equal to 0.25 - 0.3 of the length of the insert.

 An insert provided in the cavity of the disk, sealed from two ends, squeezes the flow of refrigerant directly to the walls of the disk, providing intensive cooling.

 However, in the lower part of the disk, which is the most heat-loaded, due to a decrease in the cross section of the channel formed by the sidewalls, the shell, the guide, and the insert, there is a danger of the channel becoming clogged by mechanical suspension, especially coarse particles, due to the low quality of process water used to cool valves in most metallurgical plants. Clogging of the channel with mechanical particles leads to its gradual overgrowth, worsens the conditions for cooling the disk, reducing the amount of water passing per unit time, and can lead to burnout of the disk and, therefore, to premature valve failure.

 An object of the present invention is to provide a gate valve design that improves the cooling efficiency of a particularly heat-loaded lower part of the disk, while providing the most favorable conditions to reduce the likelihood of clogging of the channel by mechanical deposits.

The problem is achieved in that in the slide valve of the blast furnace containing a lined body with a lid and a cooled lined hollow disk, consisting of a shell with two round sidewalls, located in the cooling cavity of a curved side guide for supplying refrigerant to the lower part of the cavity, inclined dividing partitions and a tubular insert located equidistant from the inner surface of the disk enclosed between the shell, curved guide and sidewalls of the part the cavity of the disk, according to the invention, the cavity of the tubular insert on the upper end side is connected to the refrigerant inlet, and on the lower end side it communicates with the disk cavity, at the lower end of the tubular insert a local narrowing of its cavity with an inner diameter of the lower end equal to 0.8 - 0 is made. 9 of the inner diameter of the upper end, and the lower end of the curved guide is bent into the disk at an angle of 25 - 30 ^o relative to the tangent to its path and protrudes beyond the lower end of the tubular insert at a distance of 0.2 - 0.25 of its length.

 Such a constructive implementation will improve the cooling efficiency of the disk and create the necessary conditions for the entrainment of mechanical suspensions by the flow of refrigerant.

 This is provided as follows. The flow of refrigerant immediately at the entrance to the disk is divided into two flows. One of them, flowing around the tubular insert on the outside, is pressed directly to the heat-loaded peripheral walls, an unprotected lining. Another refrigerant stream through the ends of the tubular insert open on both sides flows inside it, remaining practically cold within the insert, due to its isolation from heat exposure by a refrigerant stream flowing around the insert from the outside. Thus, in the lower peripheral part of the disk, the most heat-loaded during operation of the valve, a refrigerant stream is constantly supplied, which has almost the same temperature as at the inlet to the disk, which significantly increases the cooling efficiency. Local narrowing of the cavity of the tubular insert at the lower end allows to obtain a throttling effect of the refrigerant flow at the outlet of the insert, which, combined with the expansion of the flow washing the insert from the outside, caused by the lower end of the guide bent into the disk, creates a bubbling effect in the lower part of the disk, preventing mechanical settling Suspension available in the refrigerant.

 As studies on the model showed, when the inner diameter of the lower end of the insert is less than 0.8, the inner diameter of the upper end there is a danger of clogging of the cavity of the insert at the outlet of the refrigerant with a coarse mechanical suspension. When the inner diameter of the lower end of the insert is greater than 0.9, the inner diameter of the upper end significantly reduces the throttling effect at the outlet of the refrigerant flow from the insert, which, in turn, reduces the bubbling in the lower part of the disk and increases the likelihood of settling of mechanical suspension.

 If the lower end of the curved guide extends beyond the lower end of the tubular insert to a distance of less than 0.2 of its length, the required flow rate of the refrigerant in the lower part of the disk, which must be more than 1 m / s for effective removal of mechanical suspension, is not provided. If the lower end of the guide extends beyond the lower end of the tubular insert to a distance greater than 0.25 of its length, then the turbulization of the refrigerant flow occurring at the lower end of the insert creates additional hydraulic resistance to the flow of refrigerant at the outlet from the lower peripheral part of the disk and thus prevents effective removal mechanical suspension.

When the angle of the bend of the lower end of the guide into the inside of the disk at an angle of less than 25 ^o perturbation of the stream flowing around the tubular insert from the outside, slightly due to a small decrease in the flow rate, as a result of which the bubbling effect in the lower part of the disk is insufficient. When the angle of the bend of the lower end of the guide into the inside of the disk is greater than 30 ^o, the flow rate of the refrigerant in the lower part of the disk is significantly reduced and at the same time the hydraulic resistance to the flow of refrigerant in the channel formed by the lower inclined dividing partition and the guide increases, which also reduces the effect of bubbling.

To explain the invention, a specific embodiment of the invention is given below with reference to the accompanying drawings, in which:
in FIG. 1 shows the slide valve of a blast furnace heater;
in FIG. 2 - the same, longitudinal section;
in FIG. 3 - node A in FIG. 1;
in FIG. 4 - node B in FIG. 1;
in FIG. 5 - node B in FIG. 2.

The gate valve of the blast furnace heater comprises a lined case 1 with a cover 2 and a cooled lined hollow disk 3. The disk 3 consists of a shell 4 with two round sidewalls 5 located in the cooling cavity of the curved side guide 6 for supplying refrigerant to the lower part of the disk, inclined partition walls 7 and a tubular insert 8 located in the cavity enclosed between the shell 4, the sides 5 and the guide 6. The tubular insert 8 is equidistant from the inner surface of the disk. The cavity of the tubular insert 8 from the side of the upper end is connected to the pipe 9 for supplying refrigerant, and from the side of the lower end is connected with the cavity of the disk. At the lower end of the tubular insert 8, a local narrowing of its cavity is made with an inner diameter d _{1 of the} lower end equal to 0.8 - 0.9 of the inner diameter d of the upper end. The lower end of the curved guide 6 is bent into the inside of the disk at an angle α equal to 25-30 ^° relative to the tangent to its path, and protrudes beyond the lower end of the tubular insert 8 by a distance c equal to 0.2 - 0.25 of the length of the insert.

 The valve operates as follows.

 The refrigerant entering through the supply pipe 9 into the cavity of the disk 3 is divided into two flows. One flows through the channel of the disk formed by the side guide 6, the sides 5, the shell 4 and the tubular insert 8, and directly cools all the walls of the indicated part of the disk. Another refrigerant stream flows inside the tubular insert 8 and, being isolated from external heat by the first stream washing the tubular insert 8 from the outside, enters the lower, most heated part of the disk 3, practically with the temperature of entry into the disk 3, providing intensive cooling. When two flows of refrigerant meet in the lower part of the disk 3 in the region of the bent end of the guide 6, a bubbling effect occurs, which prevents settling of mechanical suspensions. Further, through the loop-shaped channel formed by the inclined dividing partitions 7, the refrigerant flows upstream into the exhaust pipe 10 through which it is removed from the cavity of the disk 3, taking with it mechanical suspensions.

 The proposed gate valve of the blast furnace heater in comparison with the known ones allows to improve the cooling conditions of the disk, reduce the likelihood of burnout of the disk due to clogging of its lower part with a mechanical suspension and, thus, increase the service life of the valve.

Claims (1)

 A damper valve for a blast furnace heater comprising a lined case with a lid and a cooled lined hollow disk, consisting of a shell with two round sidewalls, located in the cooling cavity of a curved side guide for supplying refrigerant to the lower part of the cavity, inclined dividing partitions, and a tubular insert located equidistant from the inner the surface of the disk in the enclosed between the shell, curved guide and sidewalls of the part of the disk cavity, characterized in that the cavity t the ribbed insert on the upper end side is connected to the refrigerant supply, and on the lower end side it is connected with the disk cavity, at the lower end of the tubular insert there is a local narrowing of its cavity with an inner diameter of the lower end equal to 0.8-0.9 of the inner diameter of the upper end, and the lower end of the curved guide is bent into the disk at an angle of 25-30 ° relative to the tangent to its path and protrudes beyond the lower end of the tubular insert at a distance of 0.2-0.25 of its length.

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