SK58499A3 - Device for discharging or mixing lump materials - Google Patents

Abstract

A device for discharging or mixing lump materials from a shaft furnace with a hollow body for discharging the reaction materials open at the bottom and/or at least to one side, has screws arranged in a star-shape in the hollow body. These screws have shafts of different lengths in a plane and/or one screw is a continuous screw. In one of the possible combinations of floating shafts (2) of three different lengths, the shafts are arranged in the shaft furnace (1) so as to form an eight-pointed star, the opposite floating shafts (2) having the same length. The "dead" or non-stirred area at the centre of the shaft furnace is extremely reduced in this combination.

Description

Apparatus for discharging and mixing a lump mass, in particular a partially and / or totally reduced iron ore in a blast furnace, preferably a direct reduction blast furnace consisting of a hollow body with an opening facing downwards and / or at least one side for discharging the reaction mass, The radial bolts are arranged in the bodies, whose shafts of different length are in one plane and / or one bolt is designed as a through-bolt. One possible combination of shafts (2) with interposed ends of three different lengths of sleep in the radial arrangement of the octagonal shafts in a blast furnace (1), wherein the opposed interposed shafts (2) are equally long. The empty area, that is, the inactive space in the center of the blast furnace, is greatly reduced in this combination.

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Apparatus for discharging and mixing lump mass

Technical field

The invention relates to a device for discharging and mixing a lump mass, in particular a partially and / or completely reduced iron ore in a blast furnace, preferably a direct reduction blast furnace, formed by a hollow body with an opening facing downwards and / or at least one side for discharging the reaction mass, radial screws are provided in the hollow body.

BACKGROUND OF THE INVENTION

EP-B 166 679 describes screws of the same length and cylindrical cross-sections for moving and discharging solid particles in a blast furnace, which are arranged radially and tangled at one end. By installing wedge-shaped partitions between the screws, empty areas are minimized. The disadvantage of this arrangement is that the void areas are limited by partitions, but the active volume is maintained.

EP-B 85 290 discloses a device with short tapered screws which are mounted in the center of an inclined trough, providing an angle of rest here and along the circumference. As disclosed in EP-B 166 679, the device is radially and diagonally opposed and offset by the same angle.

CH-A 376 134 describes a method for reducing iron ore to ore, wherein the lump mass is conveyed by screws arranged diagonally one above the other. The bolts have a constant spacing and height and are supported on cylindrical shafts supported on both sides.

GB-A 15 02 090 describes parallel arranged conveyors in the form of obliquely cut screws for discharging iron ore. The shafts are connected to each other by V-shaped belts and their drive is synchronized.

In the reduction of ores by reactive gases, it is economically necessary to bring only the quantity of specific gas at a greater slope than stoichiometric contact with the ore. However, this requires a homogeneous gas distribution as well as uniform settling of the solid bed in the blast furnace.

In the blast furnace, for example in the COREX process used, suspended solids are moved and discharged by radially arranged screws at the lower end of the shaft. In order to ensure that the lump mass is deposited as evenly as possible, the zone located at the end of the shaft must contain a maximum active discharge area and, in addition, a continuous movement and careful mixing of the reaction zone must be ensured. The stationary zones are characterized by very steep internal angles of rest and are formed above inactive areas. Said zones referred to as empty are disadvantageous in that the percentage volume of the reaction space becomes partially inactive. As a result of long breaks, sinters and agglomerates as well as already reduced ores can form in these areas, which impair the mass flow, thus reducing the mass reaction and also the productivity.

In the prior art devices with fixed screws at one end and the same length, there is hardly any movement in the central region of the shaft. Due to the fact that the gas flow is concentrated in the shaft center, the gases with entrained dust being fed through slots formed along the circumference, the gas distribution is not homogeneous.

It is an object of the invention to prevent the occurrence of said non-moving areas, to minimize the areas of reduced movement, while at the same time maximizing the active volume of the mass driven by the shaft. Active volume means the blast furnace area where the desired gas and suspended solids reactions take place.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The present invention relates to an apparatus for discharging and mixing a lumpy mass, in particular a partially and / or totally reduced iron ore in a blast furnace, preferably a direct reduction blast furnace, formed of a hollow body with an opening facing downwards. radial screws are provided in the hollow body, the essence of which is that the screw shafts are of different length and arranged in a single plane, preferably the diametrically opposed shafts are either of the same length and / or the construction of one screw is continuous.

Bolts of different lengths are installed so that they can also be activated by the discharge zone area that is close to the center. Said device provides a wide all-round continuous mixing and settling of the lump mass especially in the upper part of the shaft, in the area of the reaction space where the reaction process is formed.

Firstly, the invention makes it possible to achieve uniform mixing and continuous discharge of solids in the reaction region of the direct reduction shaft. The invention adjusts the device and the design of the screws optimally according to the dynamic gas conditions of the reaction components, i.e. solids and gas.

For example, by using through bolts in combination with short bolts, it is possible to substantially reduce the void area size, in particular because the substrate of the inactive suspended solids is difficult to build gradually at relatively close intervals from the active bolts. By placing, for example, 4 long screws and 4 short screws, it is possible to enlarge the active area to the peripheral edge of the zones. In the case of the installation of one adjacent long and short screw, it is possible to combine the product discharge by means of one waste pipe. Accordingly, the arrangement of the waste pipes can be better adjusted to the geometry of the connected melter gasifier. By combining short and long screws, it is possible to adjust the behavior, both in motion and in the discharge of the solid, by means of the screw design, in such a way that the discharge and mixing characteristics can be influenced. However, it is primarily possible to influence the discharge behavior of suspended solids.

According to the invention, the screws are arranged in two or more planes so that the substrate can be better moved in the lower part of the furnace.

According to another claim of the invention, the long shafts of the self-centering and / or retaining structure are opposed. When installing screws in an existing subsoil, ensure that the shaft halves are aligned and centered.

According to another claim of the invention, the threaded surfaces of the screws start from the free end of the shaft. This ensures that the core zone is optimally mixed and the reaction product is constantly discharged.

According to another claim of the invention, the screw shafts are tapered towards the center such that the active cross-section of these areas of the reaction zone that set the screws in motion is maximized.

According to another claim of the invention, the threaded surfaces of the screws have a constant spacing. This development results in a uniform feeding course over the screw cross-section.

According to another claim of the invention, the threaded surfaces of the screws have different spacing relative to the process. Due to the non-linear spacing of the threaded surfaces of the screws, it is possible to take into account the reaction course of the melter gasifier as well as the behavior of the reaction mass liquid. With respect to the mathematically simulated development of feed characteristics, it is possible to respect the reaction mass at the shaft as well as the reaction behavior of the reaction gas.

According to another claim of the invention, the drive of the shafts is provided by the connected motors. If the shafts are driven by motors, the screws can be flexibly adapted to the process and can be moved by self-drive during disassembly and during installation.

According to another claim of the invention, the short and long shafts rotate at the same speed. As regards the minimum cost of investment in equipment, x

preferably uncontrolled engine operation is proposed. Consequently, the shafts have approximately the same speed, but no steering costs are required.

According to another claim of the invention, the speeds of the individual shafts are controlled in accordance with the feed characteristics of the process. With respect to the controlled operation of the shafts, the requirements of the melter gasifier reaction zone for both energy and process can be taken into account.

According to another claim of the invention the shafts are axially movable. During inspection or in the event of an error, it is much easier to mount and disassemble the shafts. In the case of errors in the reaction zone, it is possible to definitely influence the behavior of the fluid by changing the depth of immersion of the shafts.

According to the development, the blades form threaded surfaces of the screw bodies whose shape corresponds to the feeding characteristics of the process. A reasonably simulated development can be seen in the behavior of the sintered bed of suspended solids and in the formation of a reaction zone.

According to the last claim of the invention, the shape of the threaded surfaces of the screw bodies corresponds to the process power characteristics. This adjustment ensures an optimal relationship between the reactivity of the supplied materials and the geometric conditions of the reduction shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference to the following drawings wherein:

Fig. 1 shows eight screws of different lengths in a blast furnace a

Fig. 2 six screws of different lengths in the blast furnace,

Fig. 3 combination of two screws of different lengths,

Fig. 4 arrangement of two through shafts in a blast furnace,

Fig. 5 shows a plan view of the arrangement of two through shafts in a blast furnace,

Fig. 6 a combination of one through-bolt with six tangled ends of the bolts,

Fig. 7 is the same as FIG. 6, but with the four ends of the screws engaged,

Fig. 8 a self-centering and catching version of the through-bolt,

Fig. 9 a cross-section through a previous connection,

Fig. 10 shows a self-centering and catching version of the through bolt; and

Fig. 11 is a cross-sectional view of the connection.

Examples of the invention

Fig. 1 shows an example of a combination of screws 2 with end-to-end screws of three different lengths, which are arranged radially in the shape of an octagon in a blast furnace 1. This combination substantially reduces the void area, i.e. the inactive space in the center of the blast furnace.

Fig. 2 shows an example of a combination of screwed ends 2 with two different lengths, which are arranged radially in the shape of a hexagon in a blast furnace 1. In this combination, the areas near the edge of the furnace are much less mixed and the mass to be discharged is not drained uniformly as in the example of FIG. First

Fig. 3 shows an embodiment by way of example of a combination of screws 2 with the ends of two different lengths that are arranged radially in the shape of an octagon. Movement in the region near the edge of the blast furnace 1 is better than in the case of FIG. First

Fig. 4 shows a spatial arrangement of a combination of two through-bolts 3 in a blast furnace 1.

Fig. 5 is a plan view of the arrangement of FIG. 4, wherein four screws 2 with end-to-end ends of the same length ensure optimal movement of the mass in the first level of the through screw 3.

Fig. 6 shows a combination of a through shaft 3 with six screws 2 with its ends locked in a blast furnace 1

Fig. 7 shows six screws 3 flush with the through shafts.

Fig. 8 shows the alignment of the two halves of the through screw 3, wherein the alignment is toothed for centering and engagement. The shaft half is preferably inserted into a bore in the opposite half of the shaft drilled in a centric and toothed manner during immersion in the blast furnace underlay, which is not yet discharged.

Fig. 9 shows a cross section of the toothing of the self-centering connection of the two shaft halves of a through screw.

Fig. 10 shows a longitudinal cross-sectional view of the centering connection of the two halves of the through screw 3.

Fig. 11 is a cross-sectional view of the centering alignment of the shaft half of the through bolt 3. The controlled speed of the drive motors of the two shaft halves will ensure accurate alignment and accurate characteristics of the shaft half bolts.

Claims (13)

Apparatus for discharging and mixing a lumpy mass, in particular a partial and / or totally reduced iron ore in a blast furnace, preferably a direct reduction blast furnace, formed by a hollow body with an opening facing downwards and / or at least to the side for discharging the reaction mass, radial screws are provided in the bodies, characterized in that the screw shafts have different lengths and are arranged in one plane, preferably the diametrically opposed shafts are either of the same length and / or the construction of one screw is continuous. Device according to claim 1, characterized in that the screws are arranged in two or more planes. Device according to claims 1 and 2, characterized in that the opposed long shafts are of a self-centering and / or retaining structure. The device according to claims 1 to 3, characterized in that the threaded surfaces of the screws start from the free end of the shaft. Device according to claims 1 to 4, characterized in that the screw shafts are conically shaped towards the center. Device according to one of Claims 1 to 5, characterized in that the threaded surfaces of the screws have a fixed spacing. Apparatus according to claims 1 to 6, characterized in that the threaded surfaces of the screws have different spacing according to the process. x Device according to one of Claims 1 to 7, characterized in that the connected motors are provided with shaft drives. Device according to claims 1 to 8, characterized in that the short shafts and the long shafts have the same speed. Device according to one of Claims 1 to 9, characterized in that the speed control of the individual shafts is effected in accordance with the feeding characteristics. Device according to one of Claims 1 to 10, characterized in that the shafts are axially movable. Device according to claims 1 to 11, characterized in that the threaded surfaces of the screw bodies are shaped according to the corresponding feeding characteristics of the process. Apparatus according to claims 1 to 12, characterized in that the vanes forming the threaded surfaces are shaped according to the feed characteristics. Fig. 1 I W Ί7 Fig. 3 TRW-w I I I FIG. 4 fig. 5, FIG. 6