US3693956A

US3693956A - Charging device for a metallurgical furnace

Info

Publication number: US3693956A
Application number: US33541A
Authority: US
Inventors: Peter Hendrik Nieboer
Original assignee: Demag AG
Current assignee: Mannesmann Demag AG
Priority date: 1969-09-05
Filing date: 1970-05-01
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26
Also published as: AT306074B; DE1945132A1; GB1278408A; FR2048420A5; DE1945132C3; JPS4824602B1; DE1945132B2; BE750667A; NL7013061A

Abstract

A charging device for a metallurgical furnace includes a hopper and bell assembly which are positionable in a furnace head. The hopper is pivotally mounted below a storage bin and it may be oriented by push rods to drop the charged material in any desired direction. A distributor bell is mounted within the furnace head on supporting rods in a position such that the outer periphery thereof may be engaged with a top pan portion of the furnace to provide a seal for preventing the further downflow of the charging material but not for the purpose of providing a pressure gas seal. A feature of the construction is the suspension of the bell which is by two suspension rods which pass through side openings in the distributor bell and which connect to a central supporting bridge extending therebetween. The bridge has a universal pivotal connection between the bridges and the distributor bell. Universal pivotal movement is permitted by the bell on the suspension rods and the passage of the rods through the bell walls is effected in the area of a spherical projecting portion of the bell having a spherical outer generating surface which may slide within a generating surface of contoured flow bodies which are arranged around the supporting rods or coverings.

Description

United States Patent N ieboer Sept. 26, 1972 [54] CHARGING DEVICE FOR A METALLURGICAL FURNACE [72] Inventor: Peter Hendrik Nieboer, Kapellen/Moers, Germany [73] Assignee: Demag Aktiengesellschaft, Duisburg,

Germany 22 Filed: May 1, 1970 211 Appl.No.: 33,541

[30] Foreign Application Priority Data Sept. 5, 1969 Germany ..P 19 45 132.2

Primary Examiner-Gerald A. Dost Attorney-McGlew and Toren [5 7] ABSTRACT A charging device for a metallurgical furnace includes a hopper and bell assembly which are positionable in a furnace head. The hopper is pivotally mounted below a storage bin and it may be oriented by push rods to drop the charged material in any desired direction. A distributor bell is mounted within the furnace head on supporting rods in a position such that the outer periphery thereof may be engaged with a top pan portion of the furnace to provide a seal for preventing the further downflow of the charging material but not for the purpose of providing a pressure gas seal. A feature of the construction is the suspension of the bell which is by two suspension rods which pass through side openings in the distributor bell and which connect to a central supporting bridge extending therebetween. The bridge has a universal pivotal connection between the bridges and the distributor bell. Universal pivotal movement is permitted by the bell on the suspension rods and the passage of the rods through the bell walls is effected in the area of a spherical projecting portion of the bell having a spherical outer generating surface which may slide within a generating surface of contoured flow bodies which are arranged around the supporting rods or coverings.

9 Claims, 1 Drawing Figure CHARGING DEVICE FOR A METALLURGICAL FURNACEI SUMMARY OF THE INVENTION This invention relates in general to the construction of metallurgical furnaces and in particular, to a new and useful bell and hopper arrangement for shaft furnaces, particularly blast furnaces which include a device for sealing the furnace chamber from the storage bin, and having a distributor bell which bears on a beam or bridge held by a plurality of suspension rods below the hopper.

The distributor bells have been known which are arranged as a bottom member of abell and hopper arrangement in a furnace chamber above the charging surface. The distributor bell acts on the bulk material which is charged into the furnace in such a way that the material is deposited in ring layers of varying diameter -on the charging surface. A satisfactory deposit of material is only effected if a conical outflow can take place over the distributor bell. Since the distributor bells must be connected, however, in some way with the furnace head which surrounds them, and since the considerable weight of several tons requires a firm support, additional holding members are generally required to absorb the load of the distributor bell. To the weight of the distributor bell must be added the weight of the moving bulk material so that both vertical weight forces and the force impulses in transverse directions must be supported.

According to a known solution the swinging of the distributor bell at a corresponding weight absorption can be effected so that a beam supporting the distributor bell extends through the conical wall of the bell and tie rods are provided at the ends of the beam. The tie rods traverse the furnace head at a higher point and can be packed in a satisfactory manner both for blast furnace operation at normal pressures and at high pressures. With an ever increasing diameter of the distributor bell, corresponding to the increasing of the diameters of the blast furnaces which are employed, it becomes difficult to conduct the material uniformly over the distributor bell. In the known solutions of the problem the run off from the distributor bell is distributed because the arm on which the bell bears must be extended beyond the bell in order to obtain the corresponding connecting points for the suspension rods. A disturbance of the flow causes the charging material to slide off unevenly on the conical surface of the bell at one point more than another point. Accordingly, the charging material is no longer deposited on the charging surface and in rings of uniform cross section, but rather in interrupted rings.

In accordance with the present invention a satisfactory outflow from the discharge off the edge of a distributor bell is accomplished in an arrangement in which the distributor bell has no gas scaling function but the sealing of the furnace takes place at a higher point and the distributor bell itself only provides a holding action on the material within the head. In the ar rangement of the invention the hollow conical bell is provided with a cross bridge for securing one or more suspension rods which are directed through openings adjacent the top of the bell to a support above the furnace head. With the invention there are no beams protruding through the shell into the furnace chamber I but rather the supporting rods themselves are mounted on the bell with an exterior covering shaped to provide even flow of the, material and shaped to provide 'a spherical pivotal surface with a projecting portion defined on the bell around the opening for the push rod. The push rods connect to a bridge member which in turn provides a male socket portion for universally pivotally holding the bell thereon. With the inventive construction only suspension rods which are stressed for tension and which can have a smaller diameter then the beams which were required heretofore, will be in the path of the charging material. In addition, while heretofore, the load of the charging material and of the distributor bell have exerted considerable bending moments on the beam the invention applies the stress completely to the suspension rods which are capable of producing the necessary mobility with these distributor bells.

The distributor bell must have a certain flexibility characteristics in the heat of the furnace chamber in order to absorb deformations of the wall thereof. On the other hand, the suspension rods in the path of the charging material are less disturbing since a smaller number is required due to the tensile load than is the case at the present state of technology when several such beams are employed. The limitation of the length of the bridge with simultaneous extension of the suspension rods through the conical bevel of the distributor bell yields therefore a favorable combination for solving stress problems and arrangement problems simultaneously.

The action of the construction of the invention is decidedly different from the action of the known traverse on furnace top bells. As known, the charging material flows over the traverse which splits the current of flow so that a trough of material is formed below the traverse on the charging surface. It is assumed that the bell suspended on the traverse works as a distributor bell which can be attributed to the known subject only in a variation. The trough formed extends as a valley across the furnace diameter. This inconvenience is completely avoided with the inventive construction. The charging material flows around the suspension rods with far less disturbance and several single currents combine in time because of the flow conditions on the bell surface ahead of the discharge edge of the bell. In this way, a uniform charging surface without any valley formation is obtained in the furnace. The invention is also characterized by the fact that the valley formation is avoided for all materials. The same conditions are obtained when the material is accumulated temporarily between the distributor bell and the top pan of the furnace head.

In order to favorably influence the flow of material over the bell surface it is advisible to arrange openings for the suspension rods in the cone shell of the distributor bell itself at the upper third portion of the length of the conical generatrix. The flow material can thus close any existing empty path behind the suspension rods and form an equalized thickness of the flow layer up to the discharge edge from the bell.

A particularly favorable embodiment of the invention in all of its features comprises a design of a hell with openings for the passage of the suspension rods at mounting of the bell in this manner also provides the pivotal suspension of the bell so that it may freely pivotally move on its ball and socket connection to the bridge member carried at the lower end of the suspension rods.'The suspension rods themselves are arranged in the openings with sufficient play and do not impair the movement of the distributor bell. The rods may move in order to compensate for any displacement of the distributor bell. In such an event there is a slight bending stress which remains very small, however, compared to the tensile stress.

A further feature of the invention is that the lower ends of the suspension rods in the areas which they project into the furnace head are covered by wear plates or wear pieces which are made up of two part assemblies which have interengaging projecting and recessed porgagement of the two parts with their interlocking teeth permit slight bending during the displacement of the distributor bell.

The distributor bell itself also is provided with a removable wear head adjacent its apex which may be removed for accessto the socket portion of the universal joint which supports the bell on the bridge members carried by the suspension rods. An important consideration is thefact that the bell is pivotally universally supported on a spherical body which is carried on the bridge which is held at the lower ends of the suspension rods. The dimensions of the spherical body depend practically on the available length of the bridge body and the bridge body permits a diameter of the spherical joint such that the surface pressure between the spherical body of the ball and socket joint and the socket of the bell is greatly reduced. A special advantage which is obtained is that the invention can be so used with that concentric spherical surface of the distributor bell step bearings and a support of the flow bodies of the edges of the openings exist. A movement of the distributor bell will therefore take place in ideal form.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The only FIGURE of the drawings is a transverse sectional view of the upper portion of a furnace head having a hopper and distributor bell arrangement constructed in accordance with the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, in particular, the invention embodied therein comprises a material charging connection for a furnace generally designated 50 which includes a furnace head portion 1 having a raised charging opening which is surrounded by a top pan. A hopper mounting housing 3 is formed over the furnace head immediately below a charging storage bin 8.The hopper 4 is mounted in gimbals 52 in a ring 5 which is pivotally connected through a universal joint 6 in the housing 3. Thus, the hopper 4 can be turned in any desired inclined position through manipulation of the

push rod

7, 7 which projects into the housing from respective sides thereof. In this way, the charging material issuing from a storage bin may be directed into a desired area over a distributor bell 14.

In accordance with the invention material is retained within the top pan 2 of the furnace by the bell 14 when it is in the uppermost position indicated in which it provides a seal 38 at the location 37 of the rim of the top pan 2 but only for the purpose of retaining the material and not for providing a pressure seal or gas seal.

In accordance with a feature of the invention, the bell 14 is pivotally supported on a bridge 12 which is carried by one or more suspension rods 9, 9 (two suspension rods being indicated). The suspension rods are adapted to be connected at their upper ends to lifting mechanism (not shown). In the arrangement of the invention, the rods 9 are directed upwardly through the furnace head 1 in tubular elements or pipes 10 in which the pressure of the furnace prevails. Such a pressure can also be produced by a supply of a purified top gas in such a way that when the storage bin is opened the pressure therein is always the same as in the furnace chamber. Pressure equalization is always necessary in order to be able to move the distributor bells 14 with a large diameter. The bridge 12 forms a step bearing for the distributor bell 14, this bearing is in the formof a ball and socket joint including a ball portion 35 which is pivotally received within a socket portion 34 of the bell 14. The bridge 12 which extends inside the hollow portion of the bell 14 has a pronounced cross section in order to transmit a considerable load at the location 16 to the lower ends of the suspension rods 9.

In accordance with another feature of the invention, the generatrix of the conical exterior wall 17 of the bell 14 is provided with openings through which the suspension rods 9 extend. The openings have at their edges projecting portions or spherical suspension surfaces 20 of a configuration corresponding approximately to a falling water drop. The outer surface 21 of the bead 20 defines a spherical superificies providing a pivotal surface for pivotally supporting the underside 22 of an exterior cover or flow body 23 which is arranged around the lower end of each suspension rod 9. The flow bodies 23 as well as wear pieces 25 are made up of two or more interfitting segmental parts having projections and recess portions in the form of a hook which interengage when the parts are arranged around the associated suspension rods 9. When assemblied, the wear pieces 25, and the flow body 23, define bores 24 through the rods 9 extend. The interengagement of the parts of the wear pieces 25 and the flow bodies 23 is such that they prevent, by frictional contact, any axial movement while permitting an expedient assembly and disassembly of the device.

In accordance with a further feature of the invention the distributor bell 14 is provided with a conical cap 30 which covers a central opening 29 near the apex and which provides a wearing head or cap which may be removed for access to a central bore 33 which terminates in the spherical recess or socket 34 at the lower end. The central bore is formed in a tubular member which forms the socket 34 and it is supported on an internal ledge portion or partition 32 defined on the interior of the bell 14. An intermediate plate 36 which is mounted on the bridge holds the spherical portion 39 of the ball and socket joint 13. i

What is claimed is:

1. A furnace material charging device for positioning in a shaft furnace, particularly a blast furnace having a head with an annular top pan around the lower end of a charging hopper, comprising a hollow substantially conical distributor bell adapted to be positioned below the hopper, a supporting bridge located within said bell and universally pivotally supporting said bell, and at least two supporting rods connected to said bridge at spaced locations, each of said rods extending through said bell and having upper ends which are adapted to be connected to a lifting device.

2. A furnace, according to claim 1, wherein said bell and said extension rod have exterior partially spherical interengageable surfaces which permit pivotal movement of said bell relative to said suspension rod.

3. A furnace material charging device for positioning in a shaft furnace, particularly a blast furnace having a head with an annular top pan-around the lower end of a charging hopper, comprising a hollow conical distributor bell adapted to be positioned below the hopper and having at least one opening therethrough, a supporting bridge located within said bell and universally pivotally supporting said bell, and at least one suspension rod connected to and supporting said bridge and extending upwardly through the opening of said bell; and 'at least two supporting rods connected to said bridge at spaced locations, each of said rods extending through a respective openings of said bell, said bell having an opening in addition to said one opening for the other of said rods, each of said rods having an exterior portion defining a partially spherical surface which are interengaged with said bell to permit pivotal movement of said bell.

4. A furnace material charging device for positioning in a shaft furnace, particularly a blast furnace having a head with an annular top pan around the lower end of a charging hopper, comprising a hollow conical distributor bell adapted to be positioned below the hopper and having at least one opening therethrough, a supporting formin a a iall s herical su ace, said sus ension rods ea ch i cl t idin a ii exterior ow body there around having a spherical surface engaged with the spherical surface of said beads.

5. A furnace, according to claim 4, wherein said exterior surface around said suspension rods comprise flow bodies shaped with said bead to provide for a desirable flow of material therearound and each being made up of a plurality of parts which are assembled around the respective suspension rods said parts each having hooking engagement means thereon for interengaging said parts around said suspension rods.

6. A furnace, according to claim 5, including at least one wear piece surrounding said suspension rods said wear piece comprising at least two partially annular parts extending around a portion of the periphery of said suspension rod and each including hook means for interengagement to the corresponding next adjacent part and for holding said parts around said suspension rod.

7. A furnace, according to claim 6, including a flow body around said suspension rod forming a downwardly extending spherical surface, said distributor bell having a bead formation forming a spherical surface slidably engaged with thespherical surface of said flow body, said flow body and said bead forming a streamline surface for facilitating the flow of material thereof.

8. A furnace material charging device for positioning in a shaft furnace, particularly a blast furnace, having a head with an annular top pan around the lower end of a charging hopper, comprising a hollow conical distributor bell adapted to be positioned below-the hopper and having at least one opening therethrough, a supporting bridge located within said bell and universally pivotally supporting said bell, and at least one suspension rod connected to and supporting said bridge and extending upwardly through the opening of said bell, said bell including a conical central cap at the apex thereof which is removable.

9. A furnace, according to claim 8, wherein said bridge includes a spherical body centrally positioned thereon said bell having a spherical receiving socket located below said removable cap.

Claims

3. A furnace material charging device for positioning in a shaft furnace, particularly a blast furnace having a head with an annular top pan around the lower end of a charging hopper, comprising a hollow conical distributor bell adapted to be positioned below the hopper and having at least one opening therethrough, a supporting bridge located within said bell and universally pivotally supporting said bell, and at least one suspension rod connected to and supporting said bridge and extending upwardly through the opening of said bell; and at least two supporting rods connected to said bridge at spaced locations, each of said rods extending through a respective openings of said bell, said bell having an opening in addition to said one opening for the other of said rods, each of said rods having an exterior portion defining a partially spherical surface which are interengaged with said bell to permit pivotal movement of said bell.

4. A furnace material charging device for positioning in a shaft furnace, particularly a blast furnace having a head with an annular top pan around the lower end of a charging hopper, comprising a hollow conical distributor bell adapted to be positioned below the hopper and having at least one opening therethrough, a supporting bridge located within said bell and universally pivotally supporting said bell, and at least one suspension rod connected to and supporting said bridge and extending upwardly through the opening of said bell, a plurality of suspension rods, said bell having an opening adjacent the top thereof in a side wall for each of said suspension rods, each of said suspension rods being connected to said bridge, said bridge being centrally pivotally connected to said distributor bell said distributor bell having a projecting bead around each of said openings forming a partially spherical surface, said suspension rods each including an exterior flow body therearound having a spherical surface engaged with the spherical surface of said beads.

7. A furnace, according to claim 6, including a flow body around said suspension rod forming a downwardly extending spherical surface, said distributor bell having a bead formation forming a spherical surface slidably engaged with the spherical surface of said flow body, said flow body and said bead forming a streamline surface for facilitating the flow of material thereof.

8. A furnace material charging device for positioning in a shaft furnace, particularly a blast furnace, having a head with an annular top pan around the lower end of a charging hopper, comprising a hollow conical dIstributor bell adapted to be positioned below the hopper and having at least one opening therethrough, a supporting bridge located within said bell and universally pivotally supporting said bell, and at least one suspension rod connected to and supporting said bridge and extending upwardly through the opening of said bell, said bell including a conical central cap at the apex thereof which is removable.