TWI493045B - Hot blast control valve for a metallurgical installation - Google Patents

Description

Hot air control valve for metallurgical equipment

The present invention generally relates to a hot air control valve for a metallurgical plant, the hot air control valve being specifically for controlling the hot air flow of the blast furnace.

In a blast furnace, hot air (commonly referred to as hot blast) is injected into the furnace to aid in the reduction of ore in the furnace.

The air is heated to 1250 ° C before being sent to the furnace as hot air. The reducing gas or hot air can be mixed into the hot air to further assist in the reduction of the ore in the furnace. Any valve used to control hot air flow is exposed to extreme environments where the gas temperature is very high and can also be extremely aggressive.

It is known to arrange a butterfly valve in the hot air transfer duct to control the flow of hot air to the furnace. Such a butterfly valve is known from JP 09095720, which includes a disk-shaped control member mounted on a rotational axis disposed at a central position in the hot air path. In the closed position, the disk control member is perpendicular to the hot air flow and substantially blocks the path of the hot air. The control member can then be rotated 90° into the open position wherein the control member is substantially parallel to the hot air flow so that hot air can flow through the valve. In fact, hot air flows over both sides of the control. A drawback of such a butterfly valve is that since the axis of rotation is arranged in the center of the duct, the control member is still in the hot air path even when the control member is in the fully open position. In fact, even if the flow restriction of the control member is reduced to a minimum in the open position, the control member exhibits a free flow that blocks hot air from passing through the valve. In addition, since the control member is exposed to extremely high temperatures, a cooling passage for cooling the disk-shaped control member is provided. However, such cooling is often insufficient to prevent damage to the control. As a result, the control piece needs to be replaced after a while. However, replacing the control is particularly difficult since only the control valve has been disassembled and removed from the pipe, the only way to access the control. As a result, repair time and cost are quite high.

As described above, the reliability and durability of the butterfly hot air control valve are impaired by exposure to such extreme environments. Such control valves not only have the drawback of forming a barrier in the hot air path, but also require high manufacturing costs as well as intensive, frequent and costly maintenance operations. It is therefore necessary to provide a better implemented hot air control valve, preferably reducing the costs involved.

It is an object of the present invention to provide an improved hot air control valve that does not suffer from the above disadvantages. This object is achieved by a hot air control valve as claimed in claim 1.

The present invention provides a hot air control valve for a metallurgical plant that is specifically used to control the hot air flow of a blast furnace. The hot air control valve includes: a metal valve housing having a refractory lining defining a gas passage therein; and a valve member rotatably disposed in the gas passage to pass between the open position and the closed position about the rotation axis by the valve member Rotation can change the free path in the gas channel. The valve member has a housing that is rotationally symmetrical about the axis of rotation and has a through passage that is disposed in the valve member in a direction transverse to the axis of rotation of the valve member. The cross section of the through passage is substantially the same as the cross section of the gas passage. Further, the through passage is disposed in the valve member to align the through passage with the gas passage when the valve member is in the open position.

According to an important aspect of the invention, the valve member includes a cylindrical portion having a first base and an opposite second base; the first base is provided with attachment means for connecting the valve member to the shaft; the diameter of the cylindrical portion Larger than the diameter of the gas passage. The valve member further includes a hemispherical portion having a base disposed on the second base of the cylindrical portion.

Such a hot air control valve has the advantage that hot air can freely flow through the through passage of the control member when the control member is in the open position. In fact, the control does not constitute a blockage of the hot air flow. A pressure drop of up to 20% is produced when the butterfly control valve is in the open position, whereas the pressure drop across the open control valve according to the invention is negligible. In addition, in their closed position, the butterfly control valve typically exhibits considerable leakage (up to 40%). Due to the special shape of the hot air control valve according to the present invention (Cylinder part and hemisphere part), this leakage can be greatly reduced. Thereby improved control of the hot air flow is possible.

Preferably, the gas passage and the through passage have a circular cross section, and the diameter of the through passage substantially corresponds to the diameter of the gas passage.

Advantageously, the axis of the through passage is perpendicular to the axis of rotation of the valve member.

Preferably, the diameter of the base of the hemispherical portion corresponds to the diameter of the second base of the cylindrical portion.

Advantageously, the base of the hemispherical portion is arranged to lie on the axis of the gas channel.

According to an important aspect of the invention, preferably, the connecting means comprises a connecting shoe on the first base of the cylindrical portion, the connecting shoe forming a circumferential groove having a joint flange therein, the joint flange facing the cylinder The first base of the body portion. The joint flange can be parallel to the first base of the cylindrical portion. Preferably, however, the joint flange tapers away from the first base at an angle toward the outer circumference of the first base.

According to an embodiment of the invention, the shaft comprises a clamping device that engages a circumferential groove in the connection pedestal, the clamping device being transmitted to the valve member by the rotational movement of the clamping device of the shaft such that the contact of the clamping device The surface is in intimate contact with the joint flange of the connection shoe. Preferably, refractory insulation paper is disposed between the contact surface of the clamping device and the joint flange of the connection shoe.

Advantageously, the clamping device comprises at least two clamping elements that engage the circumferential groove, the clamping element being coupled to the enlarged head of the shaft. Preferably, the clamping device further comprises a retaining ring that engages the at least two clamping elements to prevent the clamping element from moving in a direction away from the connecting pedestal.

At least two clamping elements can be screwed to the enlarged head; the screw is preferably provided with a spring means for pulling the clamping element towards the enlarged head, the screw preferably being provided with a sleeve for defining the movement of the screw.

In order to cool the shaft and the connecting device, advantageously the shaft is provided for conveying the coolant A cooling passage for the enlarged head of the shaft.

An intermediate plate may be arranged between the at least two clamping elements and the enlarged head of the shaft. The intermediate plate may be provided with an auxiliary shaft that engages in a mating recess that is disposed in the connecting pedestal of the valve member to create a form-fit connection. This arrangement can be used to ensure that the valve member is entrained by the shape-matching connection provided by the auxiliary shaft in the event of a failed frictional connection between the contact surface and the engagement flange.

The clamping element and/or the retaining ring and/or the intermediate plate and/or the auxiliary shaft are made of heat-resistant steel. The thermally insulating material is disposed in a gap between the various components of the clamping device. Advantageously, the valve member is formed as a single piece from a refractory or ceramic material.

Preferably, the metal valve housing includes a lateral opening for operating the valve member through the shaft; the diameter of the lateral opening is at least slightly larger than the diameter of the cylindrical portion of the valve member. This lateral opening allows for easy removal of the valve member from the valve housing for maintenance purposes. In order to access the valve to be serviced, it is not necessary to remove the valve housing.

Preferably, any bearing for the shaft is placed on the outside of the metal valve housing such that the bearing does not suffer from the extremely harsh environment of the metal valve housing. Therefore, the service life of the bearing is extended.

An annular groove is disposed in a circumferential region of the first base of the valve member, the annular thin plate engaging the annular groove to form a labyrinth seal. This labyrinth seal prevents a large amount of hot air from entering the connecting device and moving toward the main sealing device. This extends the life of the primary seal.

Fig. 1 schematically shows a hot air control valve for installation in a hot air duct. Hot air control valve 10 includes a metal valve housing 12 having an inlet end 14 and an outlet end 16, each of which includes a connecting flange 18 for connection to a conduit (not shown). Internally, the valve housing 12 includes a heat resistant lining 20 defining a gas passage 22 therein for conveying hot air from the inlet end 14 to the outlet end 16.

The valve member 24 is rotatably disposed in the gas passage 22 to be opened by the valve member 24. The rotation between the mouth position and the outlet position about the axis of rotation 26 changes the free passage in the gas passage. The valve member 24 has a housing that is rotationally symmetrical about an axis of rotation 26 . The housing of the valve member 24 will be described more closely later.

The valve member 24 includes a through passage 28 having a cross section substantially the same as the cross section of the gas passage 22. The through passage 28 is arranged such that when the valve member 24 is in the open position as shown in FIG. 1, the through passage 28 is aligned with the gas passage 22 and forms a continuous portion of the gas passage 22 so that hot air can freely pass from the hot air control valve 10. The inlet end 14 flows to the outlet end 16.

The valve member 24 includes a cylindrical portion 30 having a first base 32 having a connecting pedestal 34 for connecting the valve member 24 to the shaft 36. The connection between the shaft 36 and the valve member 24 will be described more closely later with reference to FIG.

The valve housing 12 is provided with a transverse opening 38 to allow the shaft 36 to extend from the outside of the valve housing into the valve housing and to the valve member 24. The transverse opening 38 is sized to allow the valve member 24 to be removed from the valve housing 12 through the lateral opening. Thus, the valve member 24 can be repaired and replaced easily and quickly. It is not necessary to disassemble the hot air control valve 10 from the pipe at the connection flange 18 in order to access the valve member 24. By connecting the shaft support member 40 to the attachment flange 42, the assembly including the valve member 24 and the shaft 36 is held in place.

Therein, the shaft support assembly 40 includes a shaft bearing 44 and a primary seal 46 (preferably in the form of a stuffing box). It should be noted that these elements are all disposed outside of the valve housing 12, i.e., away from the erosive environment in the valve housing 12.

Referring now to Figure 2, the connection between the shaft 36 and the valve member 24 will be described more closely. At the central portion of the first base 32, the valve member 24 includes a connecting pedestal 34 formed with a circumferential groove 50 having an angled engagement flange 52 therein. The shaft 36 includes a clamping device that engages the circumferential groove 50. The clamping device is formed by at least two clamping elements 54, which have projections 56 that engage the circumferential grooves 50. The cross section of the projection 56 of the clamping element 54 substantially corresponds to the cross section of the groove 50 of the connection shoe 34. The contact surface 58 of the projection 56 is in intimate contact with the engagement flange 52 of the connection shoe 34 such that the clamping element 54 is rotationally fixed to the shaft 36. The rotational motion is transmitted to the valve member 24 through the contact surface 58 and the engagement flange 52. The refractory insulating paper 60 can be sandwiched between the contact surface 58 and the engagement flange 52 to further improve the force transmitted from the shaft 36 to the valve member 24.

The at least two clamping elements 54 are prevented from radially outward movement by a retaining ring 62 that engages a circumferential groove 64 disposed in the clamping element 54.

The clamping element 54 is coupled to the enlarged head 66 of the shaft 36 by a screw 68. The screw 68 pulls the clamping element 54 toward the enlarged head 66. In doing so, the screw 68 also tensions the contact surface 58 against the engagement flange 52 to ensure good contact of the clamping member 54 with the connection pedestal 34 of the valve member 24. The enlarged head 66 can be formed as a single piece with the shaft 36. However, preferably, the enlarged head 66 is formed separately and fixed to the shaft 36 by welding.

An intermediate plate 70 is also disposed between the clamping element 54 and the enlarged head 66. An auxiliary shaft (e.g., a polygonal shaft 72 disposed on the intermediate plate 70) aligned with the axis of rotation 26 of the shaft 36 and a corresponding polygonal recess 74 in the connecting shoe 34 of the valve member 24 provides the intermediate plate 70 and the valve member 24 The shape matches between the connections. In the event that the frictional connection between the contact surface 58 and the engagement flange 52 fails, the actuation of the valve member 24 can be achieved by means of a form-fit connection provided by the polygonal shaft 72.

In the enlarged head 66 and intermediate plate 70, preferably, the screw 68 is guided through the sleeve 76 which contacts the clamping element 54 and thereby limits the travel of the screw 68. The sleeve 76 prevents the screw 68 from being over-tightened and prevents the clamping element 54 or the connection pedestal 34 from being potentially compromised due to over-tightening. Preferably, the screw is also provided with a pretensioned spring means 78 between the intermediate plate 70 and the nut 80. The spring means 78 (which may be in the form of a disc spring) ensures that the load on the contact area (the joint flange 52 and the contact surface) is defined as a predetermined tension. In fact, the load on the contact area is variable due to temperature changes. Due to the spring means 78 and the sleeve 76, the load does not exceed a predetermined threshold.

Cooling water can be applied to the enlarged head 66 of the shaft 36 by the shaft 36 itself. At the head of the shaft, the cooling water is sprayed radially and collected by any known means.

Another important aspect of the invention is the slower heat transfer from the valve member 24 to the shaft 36. In fact, the valve member 24 arranged to be in direct contact with the hot air can easily reach a temperature in the region of 1200 °C. To endure this temperature, preferably the valve member 24 is made of a refractory or ceramic material. The various components between the valve member 24 and the shaft 36, i.e., the clamping member 54, the retaining ring 62, the intermediate plate 70, and the polygonal shaft 72 are made of heat resistant steel to reduce heat transfer to the shaft 36. In order to further reduce heat transfer, gaps 82 are provided between the various elements, and an insulating material such as an insulating felt is disposed in these gaps 82. The interaction of the various components with the insulating material allows the temperature of the shaft 36 to be lowered to 40 °C.

As described above, the sealing of the hot air control valve 10 is mainly achieved by the main sealing device 46 disposed outside the valve casing 12. However, an annular sheet 84 that is parallel and coaxially disposed with the axis of rotation 26 can provide an additional seal. The annular sheet 84 includes a projection 86 that engages an annular groove 88 disposed in the periphery of the first base 32 of the valve member 24. The extension 86 that engages the annular groove 88 forms a labyrinth seal to prevent large amounts of hot air from entering the connection and toward the main seal 46.

A preferred embodiment of the valve member 24 is shown in FIG. The valve member 24 is shown having an outer casing formed by a cylindrical portion 30 having a first base 32 and an opposite second base 90, the hemispherical portion being connected by the base of the hemispherical portion. To the second base 90 of the cylindrical portion 30. The base of the hemispherical portion 92 and the second base 90 have the same diameter. The first base 32 includes a connection pedestal 34 for connection to a shaft. Preferably, the hemispherical portion 92, the cylindrical portion 30 and the connection pedestal 34 are formed as a single piece. The through passage 28 is disposed such that its central axis lies in a plane including the second base 90.

10‧‧‧Hot air control valve

12‧‧‧ valve housing

14‧‧‧ entrance end

16‧‧‧export end

18‧‧‧Connecting flange

20‧‧‧refractory lining

22‧‧‧ gas passage

24‧‧‧ valve parts

26‧‧‧Rotation axis

28‧‧‧through passage

30‧‧‧Cylinder part

32‧‧‧First base

34‧‧‧Connecting pedestal

36‧‧‧Axis

38‧‧‧lateral opening

40‧‧‧Axis support assembly

42‧‧‧Connecting flange

44‧‧‧ shaft bearing

46‧‧‧Main sealing device

50‧‧‧Circular groove

52‧‧‧Joint flange

54‧‧‧Clamping elements

56‧‧‧Protruding

58‧‧‧Contact surface

60‧‧‧ Refractory insulation paper

62‧‧‧Fixed ring

64‧‧‧Circular groove

66‧‧‧Expanding the head

68‧‧‧ screws

70‧‧‧Intermediate board

72‧‧‧Polygon shaft

74‧‧‧Polygonal grooves

76‧‧‧ casing

78‧‧‧Spring device

80‧‧‧ nuts

82‧‧‧ gap

84‧‧‧Circular sheet

86‧‧‧Outreach

88‧‧‧ annular groove

90‧‧‧Second base

92‧‧‧hemispherical part

94‧‧‧ center axis

Preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which: FIG. 1 is a cross-sectional view through a hot-air control valve according to the present invention; FIG. 2 is a connection between the shaft and the valve member of FIG. A magnified view of the valve member; and Figure 3 is a perspective view of the valve member in accordance with the preferred embodiment of Figure 1.

10‧‧‧Hot air control valve

12‧‧‧ valve housing

14‧‧‧ entrance end

16‧‧‧export end

18‧‧‧Connecting flange

20‧‧‧refractory lining

24‧‧‧ valve parts

26‧‧‧Rotation axis

28‧‧‧through passage

30‧‧‧Cylinder part

32‧‧‧First base

34‧‧‧Connecting pedestal

36‧‧‧Axis

38‧‧‧lateral opening

40‧‧‧Axis support assembly

42‧‧‧Connecting flange

44‧‧‧ shaft bearing

46‧‧‧Main sealing device

Claims (20)

A hot air control valve for metallurgical equipment, specifically for controlling hot air flow of a blast furnace, the hot air control valve comprising: a metal valve casing having a refractory lining defining a gas passage therein; a valve member rotatably disposed on the In the gas passage, a free passage in the gas passage can be changed by rotation between the open position and the closed position about the rotation axis by the valve member; the valve member having a housing that is rotationally symmetrical about the rotation axis a through passage that is disposed in the valve member in a direction transverse to the axis of rotation of the valve member; wherein a cross section of the through passage is substantially the same as a cross section of the gas passage; and wherein a through passage disposed in the valve member such that the through passage is aligned with the gas passage when the valve member is in an open position, wherein the valve member includes: a cylindrical portion having a first base And a second base opposite the first base, the first base being provided with connecting means for connecting the valve member to the shaft, the diameter of the cylindrical portion a diameter of the gas passage; and a hemispherical portion having a base disposed on the second base of the cylindrical portion, wherein the through passage is disposed to pass through the valve member a cylindrical portion and the hemispherical portion. The hot air control valve of claim 1, wherein the gas passage and the through passage have a circular cross section, and the diameter of the through passage substantially corresponds to a diameter of the gas passage. A hot air control valve according to claim 1 or 2, wherein the axis of the through passage is perpendicular to the rotation axis of the valve member. The hot air control valve according to claim 1, wherein a diameter of the base of the hemispherical portion corresponds to a diameter of the second base of the cylindrical portion. The hot air control valve of claim 1, wherein the base of the hemispherical portion is disposed on an axis of the gas passage. The hot air control valve according to claim 1, wherein the connecting device comprises a connecting pedestal on the first base of the cylindrical portion, the connecting pedestal forming a circumferential groove, The groove has a joint flange therein, the joint flange facing the first base of the cylindrical portion. The hot air control valve of claim 6, wherein the shaft includes a clamping device that engages the circumferential groove in the connection shoe, the clamping device is configured to The rotational movement of the clamping device of the shaft is transmitted to the valve member such that the contact surface of the clamping device is in intimate contact with the engagement flange of the connection shoe. The hot air control valve of claim 7, wherein the refractory insulation paper is disposed between the contact surface of the clamping device and the joint flange of the connection pedestal. The hot air control valve of claim 7, wherein the clamping device comprises at least two clamping elements engaged with the circumferential groove, the clamping element being coupled to the shaft for expansion head. The hot air control valve of claim 9, wherein the clamping device comprises a retaining ring, the retaining ring engaging the at least two clamping elements to prevent the clamping element from following Moving radially away from the connecting pedestal. The hot air control valve according to claim 9, wherein the at least two clamping elements are connected to the enlarged head by screws, and the screws are preferably provided for pulling the clamping elements The spring device of the enlarged head is preferably provided with a sleeve for limiting the movement of the screw. The hot air control valve according to claim 9, wherein the shaft is provided with a cooling passage for supplying the cooling liquid to the enlarged head of the shaft. The hot air control valve of claim 9, wherein the clamping device comprises an intermediate plate disposed between the at least two clamping elements and the enlarged head of the shaft. The hot air control valve according to claim 13, wherein the intermediate plate is provided with an auxiliary shaft, the auxiliary shaft is engaged in a matching groove, and the matching groove is disposed in the valve member Connect the pedestal to create a shape-matched connection. The hot air control valve according to any one of claims 9 to 14, wherein the clamping element and/or the fixing ring and/or the intermediate plate and/or the auxiliary shaft are heat resistant Made of steel. A hot air control valve as recited in claim 7, wherein the thermally insulating material is disposed in a gap between the various components of the clamping device. The hot air control valve according to claim 1, wherein the valve member is formed of a refractory material or a ceramic material as a single piece. The hot air control valve of claim 1, wherein the metal valve housing includes a lateral opening through which the valve member is operated; the lateral opening has a diameter at least slightly larger than the valve member The diameter of the cylindrical portion. A hot air control valve according to claim 1, wherein any of the bearings for the shaft is located outside the metal valve housing. The hot air control valve according to claim 1, wherein an annular groove is disposed in a circumferential area of the first base of the valve member, and the annular thin plate is engaged with the annular groove to form a labyrinth ring. Sealed.