Sealing valve arrangement for a shaft furnace charging installation

Abstract

A sealing valve arrangement for a shaft furnace charging installation, said arrangement comprising: a shutter arranged for cooperating with a valve seat; an integrated dual-motion shutter-actuating device for moving said shutter between a sealed closed position in sealing contact with the valve seat and an open position remote from the valve seat, said integrated dual-motion shutter-actuating device comprising: a primary motion assembly for moving said shutter from said sealed closed position to an undamped position wherein the shutter is released from the valve seat; a secondary motion assembly for tilting said shutter from said undamped position to said open position remote from the valve seat, said secondary motion assembly comprising a tilting arm carrying said shutter and connected to a tilting shaft that defines an axis of rotation and a tilting shaft actuator configured to impart an angular rotation about said axis to said tilting arm; wherein said integrated dual-motion shutter-actuating device further comprises a stationary outer cylindrical sleeve, wherein said primary motion assembly comprises an inner eccentric sleeve shaft rotationally mounted within said outer cylindrical sleeve and a primary motion actuator configured to impart angular rotation to said inner eccentric sleeve shaft, the primary motion being a function of the eccentricity and angular rotation of the inner eccentric sleeve shaft; and wherein said tilting shaft of said secondary motion assembly is rotationally mounted within said inner eccentric sleeve shaft of said primary motion assembly, the secondary motion being a function of the angular rotation of the tilting shaft.

Claims

1. A sealing valve arrangement for a shaft furnace charging installation, said arrangement comprising: a shutter arranged for cooperating with a valve seat; an integrated dual-motion shutter-actuating device for moving said shutter between a sealed closed position in sealing contact with the valve seat and an open position remote from the valve seat, said integrated dual-motion shutter-actuating device comprising: a primary motion assembly for moving said shutter from said sealed closed position to an unclamped position wherein the shutter is released from the valve seat; a secondary motion assembly for tilting said shutter from said unclamped position to said open position remote from the valve seat, said secondary motion assembly comprising a tilting arm carrying said shutter and connected to a tilting shaft that defines an axis of rotation and a tilting shaft actuator configured to impart an angular rotation about said axis to said tilting arm; wherein said integrated dual-motion shutter-actuating device further comprises a stationary outer cylindrical sleeve, wherein said primary motion assembly comprises an inner eccentric sleeve shaft rotationally mounted within said outer cylindrical sleeve and a primary motion actuator configured to impart angular rotation to said inner eccentric sleeve shaft, the primary motion being a function of the eccentricity and angular rotation of the inner eccentric sleeve shaft; and wherein said tilting shaft of said secondary motion assembly is rotationally mounted within said inner eccentric sleeve shaft of said primary motion assembly, the secondary motion being a function of the angular rotation of the tilting shaft.

2. The sealing valve arrangement as claimed in claim 1, wherein the inner eccentric sleeve shaft is arranged within the outer cylindrical sleeve such that its eccentricity position is located laterally by about an eccentricity distance from the center of the outer cylindrical sleeve when the shutter is in the sealed closed position.

3. The sealing valve arrangement as claimed in claim 1, wherein said primary motion assembly further comprises an outer eccentric sleeve shaft rotationally mounted within said outer cylindrical sleeve, wherein said inner eccentric sleeve shaft is rotationally mounted within said outer eccentric sleeve shaft, the primary motion being a function of the eccentricity and angular rotation of both inner and outer eccentric sleeve shafts.

4. The sealing valve arrangement as claimed in claim 3, wherein inner and outer eccentric sleeve shafts have the same eccentricity, and wherein an eccentric actuator is configured to impart a simultaneous counter-rotating angular rotation to said inner and outer eccentric sleeve shafts.

5. The sealing valve arrangement as claimed in claim 1, wherein said tilting arm is a cantilever arm that is supported at one end portion by said tilting shaft and at another end portion carries the shutter.

6. The sealing valve arrangement as claimed in claim 1, wherein said shutter is a conical, spherical, parabolic or flap type valve shutter.

7. The sealing valve arrangement as claimed in claim 1, wherein the eccentric sleeve shaft(s) are rotationally mounted with axially spaced bearings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A preferred embodiment of the disclosure will now be described, by way of example, with reference to the accompanying drawings in which:

(2) FIG. 1A-C is a series of partial vertical cross sectional views of a first embodiment of a valve sealing arrangement showing the integrated dual-motion shutter-actuating device with one eccentric sleeve shaft;

(3) FIG. 2 is a series of partial vertical cross sectional views of an embodiment such as depicted in FIG. 1 showing the valve sealing arrangement within its casing;

(4) FIG. 3A-C is a series of partial vertical cross sectional views of a second embodiment of a valve sealing arrangement showing the integrated dual-motion shutter-actuating device with one eccentric sleeve shaft with a preferred arrangement of associated actuators;

(5) FIG. 4A1-B2 is a series of cross sectional views of a third embodiment of a valve sealing arrangement showing the integrated dual-motion shutter-actuating device with two eccentric sleeve shafts; and

(6) FIG. 5A-C is a series of back views of a fourth embodiment of a valve sealing arrangement showing the integrated dual-motion shutter-actuating device with one eccentric sleeve shaft of an alternative actuator arrangement with one primary motion actuator and a tilting control rod.

(7) Further details and advantages of the present disclosure will be apparent from the following detailed description of several not limiting embodiments with reference to the attached drawings.

DETAILED DESCRIPTION

(8) FIG. 1A-C is a series of partial vertical cross sectional views of a first embodiment of a valve sealing arrangement 10 showing the integrated dual-motion shutter-actuating device with one inner eccentric sleeve shaft 20. In FIG. 1A, the shutter 40 mounted on one end of the tilting arm 30 is in the closed position firmly seated on valve seat 50. The integrated dual-motion shutter-actuating device comprises a stationary outer cylindrical sleeve 25 in which an inner eccentric sleeve shaft 20 is rotationally mounted with means of bearings 26. The inner eccentric sleeve shaft 20 can be rotated around central axis A by means of eccentric crank 21 to which it is connected.

(9) Within the offset bore of the inner eccentric sleeve shaft 20 the cylindrical shaft connected at one end to tilting arm 30 and at the other end to tilting crank 31 is mounted with means of bearings 36 to rotate about axis B when tilting crank 31 is actuated.

(10) The eccentricity in the embodiment of FIG. 1A-C is the distance between centers A and B. As a non-limiting example, in common sealing valve arrangements, the eccentricity will generally be chosen to be between 50 and 200 mm, preferably between 80 and 120 mm. In the closed position in FIG. 1A axis B is located in a vertical plane perpendicular to tilting direction comprising axis C of sealing valve (seat) 50. Stationary axis A is situated laterally from movable axis B (also called eccentricity position herein).

(11) The primary motion is effected by rotating eccentric sleeve shaft 20 by moving eccentric crank 21 from the position shown in FIG. 1A to that in FIG. 1B. At the very beginning of the unclamping motion, shutter 40 moves almost vertically down, essentially parallel to the axis C of the valve seat (see also description of FIG. 2 below). The extent of the initial almost vertical distance can be controlled by the eccentricity, the larger the eccentricity the greater the almost straight initial distance. In fact, in practice, the most important moment in terms of wear of the seat and gasket are the first few millimeters of the primary motion. Indeed, in common cases, the gaskets are firmly compressed in the sealed closed position of the shutter. Such gaskets have heights of compressibility of a few millimeters, such as approximately 3 mm. So if in such a case the shutter has been lowered by these 3 mm from the seat, there is no more contact between shutter and seat and thus the subsequent motion can be chosen more freely. During the primary motion, eccentric sleeve shaft 20 is turned by an angle of 90 counterclockwise and the path of moving axis B (and thus of the shutter) is a quadrant with a radius equal to the eccentricity until axis B is below axis A in FIG. 1B. Shutter 40 is now at a distance from the valve seat which is sufficient to start the secondary motion of tilting the tilting arm 30 with shutter 40 to a lateral parking position as illustrated in FIG. 1C.

(12) The tilting operation (secondary motion) is effected by rotating the tilting shaft around axis B by means of an actuator (not represented) turning tilting crank 31 counterclockwise at a sufficient angle to clear the passage of the valve.

(13) The initial almost straight vertical movement of a one eccentric dual-motion mechanism as described herein is further illustrated in FIG. 2. FIG. 2 illustrates a sealing valve arrangement essentially as described in connection with FIG. 1A-C within a housing 60. The curve referenced P.sub.p and P.sub.s represents the path taken by any point of the shutter (such as its center) during primary motion (P.sub.p) and secondary motion (P.sub.s). As can be seen P.sub.p initially only has a vertical component, which is generally advantageous to reduce wear of the valve seat, sealing gaskets and shutter.

(14) It is to be noted that if wear is not a (main) issue, the initial position of axis B in FIG. 1A could be chosen at a location higher or lower than axis A knowing that in such cases the initial movement will have both a vertical and an horizontal component which result in a biased unsealing of the shutter from the valve seat. By choosing an initial position which is higher than in FIG. 1A, the distance of the shutter from the valve seat will be greater, the maximum distance being twice the eccentricity (see also above).

(15) FIG. 3A-C show an arrangement similar to that of FIG. 1A-C, but with a preferred actuating mechanism. Primary motion actuator 22, e.g. a hydraulic jack, is fixed to a stationary mounting point on one end and to crank 21 on the other. By actuating actuator 22, eccentric sleeve shaft 20 is rotated to a position as illustrated in FIG. 3B. In the embodiment of FIG. 3A-C, the secondary motion (tilting) actuator 32 is connected at one end to a control rod assembly with a control rod 33, a lever 34 pivoting about a stationary point 35. The aim of the control rod assembly is to maintain the shutter arm 30 essentially vertical during the primary motion. As eccentric crank 21 is moved, control rod 33 acts on lever 34 pivoting around point 35, the lever acting on one end of actuator 32 in such a way as to keep shutter arm 30 vertical during primary motion. When primary motion is terminated, actuator 32 turns tilting shaft via tilting crank 31 to lift the shutter 40 in a parking position as illustrated in FIG. 3C.

(16) In a non-illustrated embodiment of the sealing valve arrangement, secondary motion actuator 32 can be mounted (similarly to actuator 22) to a stationary point at one end and to tilting crank 32 at the other. It is noteworthy that maintaining the shutter arm vertically during the primary motion is not essential. Furthermore, even if desired, it can be achieved by other means such as by controlling the orientation of the tilting shaft by way of its actuator 32.

(17) FIGS. 4A1 and B1 show a schematic cross section of a sealing valve arrangement wherein the integrated dual-motion shutter-actuating device comprises an inner 201 and an outer 202 eccentric sleeve shaft in an outer cylindrical sleeve 25. Both eccentrics have the same eccentricity. As a non-limiting example, in common sealing valve arrangements, each eccentricity will generally be chosen to be between 20 and 100 mm, preferably between 30 and 60 mm. Tilting shaft 37 connected at one end to the tilting arm 30 is rotationally held within the bore of the inner eccentric sleeve shaft 201. FIGS. 4A1 and B1 represent the position of the shutter before and after the primary motion, i.e. with the shutter in a sealed closed position in sealing contact with the valve seat (A1) and an open position unclamped from the valve seat (B1). FIGS. A2 and B2 depict the same situation as a transverse cross-section through the integrated dual-motion shutter-actuating device.

(18) By rotating inner and outer eccentric sleeve shafts 201 and 202 simultaneously but in opposite directions the center of the tilting shaft is moved along a straight path by a distance equal to the sum of the eccentricities if each eccentric is rotated by 90 or even up to twice the sum of eccentricities if the angular rotation is 180 for each eccentric sleeve shaft.

(19) FIG. 5A-C show an arrangement similar to that of FIG. 1A-C, but with an alternative embodiment of the integrated dual-motion shutter-actuating device. A primary motion actuator (not shown), e.g. a hydraulic jack, is fixed to a stationary mounting point on one end and to crank 21 on the other. By actuating the primary motion actuator, eccentric sleeve shaft 20 is rotated to a position as illustrated in FIG. 5B. In the embodiment of FIG. 5A-C, the secondary motion (tilting) actuator 32 is a control rod which is pivotally connected at one end to a stationary point and at the other end to the tilting shaft 37 or its associated crank 31. As eccentric crank 21 is moved, control rod 32 acts on tilting shaft 37 (via tilting crank 31) to lift the shutter 40 in a parking position as illustrated in FIG. 5C.