SI9210095A - Apparatus for heat treatment and/or flushing through granular materials by gas - Google Patents

Abstract

Apparatus for heat treatment and / or for overfilling the granular material (7) has a reception grid (1) for the treatment of the intended substances (7), under the grid a dispensing suction chamber (2) and a side chamber The edges (3) of the grate (1) are connected substantially to the lattice plane (1) is lying, for gas impermeable supporting elements (5). To get through the substances that need to processed, the processing gases can be evenly crossed, so that it is ensured uniformly after cross-section quality, the device is equipped with side walls (10) extending from the grid (1) up, and being a wall (10) are attached to the outer edges (9) of the pivots elements (5).

Description

Voest-Alpine Stahl Linz GmbH

Apparatus for the thermal treatment and / or for the degassing of granular materials

The invention relates to a device for the thermal treatment and / or degassing of granular substances, in particular for drying, firing and / or sintering of raw materials in fine particles suitable in the iron industry, with a grate for receiving the prepared substances from under the grille arranged by a suction chamber formed from the lateral edges of the grille down the extending wall of the suction chamber, and by gas-tight contact elements which are connected at the lateral edges of the grille and lie substantially in the plane of the latter.

A device of this type in which the grating synth is designed as a grating tape is known fromDE-C563 859.

The following problems are generally encountered in the treatment of granular matter by means of a device synth:

Due to the heating between sintering and subsequent cooling, most of the bulk of the substance shrinks. The shrinkage is understood to be three-dimensional, and in dimension depends on the composition of the material in the sintering grid, with the horizontal shrinkage negatively reflected in the process with the formation of the gaps in the sintering cake, and in particular with the formation of cracks in the direction of the lateral boundaries. With the crack, which progresses in the process of sintering with the pursuit of the sintered forehead, the air or the oxygen mixture needed to burn the solid fuel (carbon fraction) in the bulk makes the transition easier.

Increased gas passage at the edges leads to overtaking of the synthetic forehead at the edges in comparison with the areas near the center, and to a limited extent also to the formation of the crude phase (non-sintered material) due to the extinction of the burning forehead or the increasing supply of gas (predominantly air) to the rapid combustion of fuel without sintering as such.

Uneven burning of the edge areas and the middle prematurely increases the permeability of the sinter cake edge areas, and the combustion gas foresees to flow primarily through the path of lower resistance through the finished sinter of the edge areas, thereby further weakening the middle zones and causing an undesired zone because it occurs on sintering grids. premature cooling.

Due to the phenomena described, the quality of the sinter cake becomes uneven and the definitive end of the sintering operation slows down. The energy of the fuel input is underutilized and a good portion of it through the suction gas mixtures (15 to 20%) must be transported without benefit, but in connection with the costs, respectively. it even dilutes the concentrations of useful or harmful substances in the waste gases, rendering any associated gas treatment inefficient.

Some synth devices have been built to solve this problem, but in practice, as far as the boundary area is concerned, none of the known synth devices are satisfactory.

Following the aforementioned DE-C 563 859, an attempt was made to eliminate the proportion of harmful air by extending the lattice-strip, namely by gas-tight contact surfaces flanked on the sintering grid. However, it has proved that this solution is only usable up to a very low embankment height, namely about 13 cm in height, to cause ignition problems and, in the case of higher impoundments, the quality of sintering in the marginal area is greatly reduced.

From DE-B 10 06 163, long after the advent of DE-C 563 859, a further attempt was made to resolve the above problem. According to this document, the proportion of harmful air is to be achieved by covering the leak in the edge area at the top of the leak. With this solution, however, a qualitatively high-quality product cannot be achieved in the boundary region, since a tight and gas tight covering of the bulk cannot be achieved.

DE-C 34 46 845 discloses a solution whereby the lattice synth is replaced by a blind lattice in the boundary region. Particularly when processing an existing plant, this solution leads to a greatly reduced blower efficiency due to the reduction of the grille surface.

Until now, such energy losses have not been looked at, and today the highly valued energy in this respect requires a change in view.

DE-B 17 58 983 concerns a sintering device in which lattice panels are arranged between the side chain members. Inside the suction chamber, the link chains cause the suction chamber cross-section to be narrowed, thereby reducing the efficiency, so that this synth has essentially the same mode of operation as that known from DE-C 3 446 845 and has disadvantages.

The purpose of the invention is to eliminate these shortcomings and problems, and the invention seeks to create a device of the kind described above, in which it penetrates evenly across the edge areas even at a higher embankment height, so that even in the edge region, the post-processing substances have quality is given the same quality as the substances centered on the grid. In particular, an increase in the capacity of the plant should be achieved while reducing the specific consumption data (blower electricity and coke input in the bulk) while simultaneously balancing the quality of the material under consideration throughout the cross section.

The present invention is solved by the fact that the device is provided with side walls extending from the lattice and these side walls are connected to the supporting elements at the outer edges.

The following advantages are achieved:

possible increase of capacity for existing plant sintering by up to 20% without changing the blower, by better utilizing the capacity of the blower for the sintering process in often only marginal processing of the plant itself, or. new plant construction results in shorter, more concentrated plants, available blowers can be optimally used for the process, and a more favorable flow of air (gas) mixture per tonne of product is obtained, higher concentrations of harmful and usable substances in waste gases allow more efficient cleaning / washing of waste gases , especially for wide grating surfaces, laterally stretching loads provide static advantages for the structure of supporting elements supporting the grating (low bending tendency, light construction system), and for sintered belts, due to the reduction of the transverse sealing ratio below the grating to width synths bake between the sidewalls to a factor below 1.0 (up to about 0.85 or less on narrow strips), resulting in a further reduction of unwanted amounts of harmful air.

Preferably, the contact elements are each fixed to the frame portion supporting the grille and the side walls are supported on the support elements.

In a preferred embodiment, the side walls are each fastened to the frame part, which is flange-mounted to the frame supporting the grille, which is attached at a distance from the grille, and the supporting elements are mounted between the grille and the side walls and are also detachably attached to the frame. frame parts.

In doing so, the ends of the framing brackets, which support the grille, are expediently extended over the framed parts, the overlapping elements overlap and are in their position secured or secured. fixed with catfish.

Preferably, the width of the contact surface is 10 to 35 cm, and the connected side wall extends twice as high. The width of the contact surface will be about 10 cm for small grille surfaces and low embankment heights, and up to 35 cm for wide sinter gratings with higher fillings.

The invention will now be further explained on the basis of the drawings, in which Figs. 1 to 3 each, each embodiment, of the cross-sectional area of the device's synthetic edge.

In the embodiment of FIG. 1 is only schematically illustrated, the sintering grille 1 has a directly connected to the sintering grille 1 directly connected to the sintering grille 1, which consists of walls 4 of the suction chamber extending down from the lateral edges 3 of the sintering grille 1, and to which it is not represented. suction-draft blower. A substantially continuous contact element 5 made of gas-tight plate 6 to which the granular substance 7 to be treated or connected is connected substantially to each side edge 3 of the sintered grate 1 at each lateral edge 3. material 7 to be treated is substantially in the same bulk height 8 as the sintering grid 1.

An upstream side wall 10 is connected at each outer edge 9 of the support element 5, which, at least in the initial processing phase, laterally supports a material strand 7 to be treated on the sintering grid 1. The advanced treatment of material 7 results in the formation of the contraction described above, thereby creating a slit 11 on the side walls 10.

According to the embodiment shown in FIG. 2, the grille synth is supported on frame 12 that surrounds it. This frame 12 further extends laterally over the frame 12 extending contact elements 5, to which each outer edge 9 is attached from the plane of the lattice 1 to the extending side wall 10. Both the contact element 5 and the side wall 10 can be protected by a thermal insulator.

In FIG. 3 shows a modified embodiment in which the frame brackets 13 of the grille 1 synthrum are supported on the outwardly projecting flange 14 of the frame 12. On this flange 14, a lateral wall 10 is fixed to the overhanging elements 5 so that between the side wall and the sintering there is a gap A. In the space thus formed, the contact element 5 is fixed to the frame 12 by means of catches 16 passing through the side wall 10.

The sintering device of the invention is embedded in all processes where, for economic as well as ecological reasons, marginal effects, such as uneven piercing of permeable fillers, must be eliminated, for economic as well as ecological reasons, when grating (including pellet firing machines using the traveling grate method). because of the marginality.

In particular, the device according to the invention is embedded in the iron industry for the preparation of fine-grained raw materials for blast furnace as well as for sintering of sulphide raw materials or in the manufacture of cement clinker.

In a sintering device according to the invention, the lattice sintering can be designed in various ways, such as e.g. for grate-carts and grate-pans.

Claims (5)

PATENT APPLICATIONS 1. A device for the thermal treatment and / or degassing of granular matter (7), in particular for drying, firing and / or sintering of finely available raw materials in the iron industry, with a grate (1) for receiving the substance (7) provided for for machining, with a suction chamber (2) arranged below the grille, consisting of lateral edges (3) of the grille downstream walls (4) of the suction chamber, and with gas-tight elements (5) connecting to the lateral edges (3) gratings (1) and substantially in the plane of the lattice (1), characterized in that the device is provided with side walls (10) extending up from the grille (10) and these walls (10) are connected to the lateral edges (9) contact elements (5). Apparatus according to claim 1, characterized in that the contact elements (5) are fixed at each time to the frame part (12) supporting the grating (1) and the side walls (10) are supported on the contact elements (5) (en 2). Apparatus according to claim 1, characterized in that the side walls (10) on the frame part (12), flangeally attached to the frame (4), which support the grate (1) are each fixed at a distance (A) from the grate (A). 1) and that the mounting elements (5) are mounted between the grille (1) and the side walls (10) and also detachably attached to the frame members (12) (Fig. 3). Device according to claim 3, characterized in that the ends of the frame supports (13) supporting the grate (1) extend beyond the frame members (12), are covered by the contact elements (12) and are secured in their position by the latter. oz. fixed with the help of catfish (16) (Fig. 3). Apparatus according to one or more of Claims 1 to 4, characterized in that the width of one contact surface (5) is 10 to 35 cm and the connecting side wall (10) extends substantially twice as high.