SK277901B6 - Device for heat elaborating and/or gassing of granular materials - Google Patents

Abstract

Device is equipped with grate (1) for locating of elaborated matters (7) with suction box (2) located under the grate and for gas permeable depository elements (5), jointed on lateral edges (3) of grate (1) and laying approximately in level of grate (1). To enable the equable penetrating of elaborated matters with elaborating gases and to guarantee the equable quality in all cross-sectional the device is equipped with lateral walls (10), outputing from grate (1) uphill, and these lateral walls (10) are jointed on external edges (9) of depository elements (5).

Description

The invention relates to an apparatus for the heat treatment and / or gasification of granular materials, in particular for the drying, combustion and / or sintering of fine-grained raw materials used in iron metallurgy, provided with a grate to accommodate the materials to be treated, a suction box arranged underneath the grate. protruding from the lateral edges of the grate downwards and receiving gas-permeable elements connected to the lateral edges of the grate and lying approximately in the plane of the grate.

BACKGROUND OF THE INVENTION

A device of this type in which the sintering grate is formed by a grate strip is known from DE-C 563 859.

The following problems are generally known when processing granular materials with a sintering device:

By heating the poured substances during sintering and subsequent cooling, they tend to shrink in most cases. Of course, the shrinkage usually takes place in three spatial dimensions, depending on the material composition of the embankment on the sintering grate, and horizontal shrinkage with the formation of cracks in the sintering cake, in particular with the formation of gaps towards the side walls, proves to be disadvantageous.

The gap that follows the sintering face during the sintering process facilitates easier passage of the necessary air or oxygen mixtures when burning solid fuel (carbon content) in the embankment.

Increased gas passage at the edges leads to a leading edge of sintering at the edges relative to the bands close to the center to a limited extent, but also induces a cold run (non-sintered material) as fuel burns quickly without sintering by tearing off the combustion front or increasing gas supply ( especially air). The uneven burning of the edge zones and the center increases prematurely the permeability of the sintered cake edge zones, and the gas mixture for fuel combustion preferably flows through the least resistance of the finished sintered agglomerate and further adversely affects the center zones and causes undesirable, too premature cooling on the sintering grid.

Using the described procedures, the quality of the sintered cake is uneven and the complete completion of the sintering process is thus prolonged. The energy of the introduced fuel is not sufficiently utilized and a significant part of the gas mixture passing through (15 to 20%) must be transported costly and unnecessarily, or even dilute the concentration of valuable or harmful substances in the off-gases, thereby rendering the gas treatment ineffective.

Some sintering devices have been designed to solve this problem, but the known sintering devices are not satisfactory with respect to the peripheral areas.

According to the aforementioned DE-C 563 859, it has been attempted to prevent the effect of the false air fraction by expanding the grate strip, namely the stored areas, gas passageways and laterally connected to the sintering grid. Nevertheless, it has been shown that this device is only applicable to very low hopping heights, namely a hopping height of approximately 13 cm; ignition problems arise and sintering quality decreases considerably at higher embankments in peripheral areas.

DE-B-10 06 163 discloses a further attempt to solve this problem, long after the publication of DE-C-563 859. According to this solution, the proportion of false air should be reduced by covering the embankment in the edge area on the top side of the embankment. In this solution, however, a relatively valuable product is not achieved in the peripheral areas, since accurate and gas-tight covering of the embankment is not feasible.

DE-C-34 46 845 discloses a solution whose sintering grate is replaced by a blind grate in the peripheral region. Especially with the conversion of existing plants, this solution leads to a significantly reduced degree of blower efficiency when the grate area is reduced. So far, such energy losses have not been considered significant, but at present there is a turnaround due to the high energy price.

DE-B-17 58 983 relates to a sintering device in which the grate plates are arranged between the side chain links. The chain links located inside the suction box cause a reduction in the cross-section of the suction box and thus a reduction in the degree of efficiency, so that this known sintering device has the same effect as the apparatus of DE-C-3 446 845, and also its disadvantages.

SUMMARY OF THE INVENTION

The object of the invention is to eliminate the above-mentioned drawbacks and difficulties and to provide a device of the type described above in which the edge regions are evenly permeable even at higher embankment heights so that even the substances located in the edge region have the same quality after processing. placed in the center of the grid. In particular, an increase in plant performance is to be achieved while reducing specific consumption data - blower electric power and the amount of coke in the embankment - while maintaining uniformity in the quality of the processed material throughout the cross-section of the embankment.

This object has been achieved according to the invention in that the device is provided with side walls extending from the grate upwards and these side walls are fed to the outer edges of the receiving elements.

The following advantages are achieved:

- Possible power increase for existing sintering devices by up to 20% without blower changes, but by better use of blower capacity for the sintering process itself, in particular only by minor changes to the device. With new plant designs, shorter, compact devices are obtained;

- existing blowers can be optimally used for the process, thus requiring less gas (air) mixture per tonne of product;

- a higher concentration of harmful and / or valuable substances in the flue gas allowing a more efficient purification of the flue gas / or the gas concerned;

- especially on wide grate surfaces, lateral unloading of the load gives static advantages for the construction of the support elements supporting the grate (low sag tendency, lighter construction);

- for sintering bundles, by reducing the ratio of transverse sealing under the grate to the width of the sintered cake between the side walls, a factor of less than 1.0 (up to about 0.85 or less for narrow strips) is obtained,

EN 277901 Β6 will result in the reduction of undesirable amounts of false air.

The support elements are preferably fixed to the frame part supporting the grate, and the side walls are supported on the support elements.

According to a preferred embodiment, the side walls are fixed at a distance from the grate on a frame part fixed to the flange of the frame supporting the grate, and the receiving elements are fitted between the grate and the side walls and are also loosely fixed to the frame parts.

The ends of the frame supports, supported on the grate, projecting over the frame parts, are covered by bearing elements and secured in their position or fixed by bolts.

The width of the receiving surface is preferably 10 to 35 cm and the extended side wall protrudes approximately twice as high, the width of the receiving surface is 10 cm for small grate surfaces and small hopping heights and up to 35 cm for wide sintering grates.

Overview of the figures in the drawing

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 3 show cross-sectional embodiments of the edge portion of the sintering device.

DETAILED DESCRIPTION OF THE INVENTION

According to the embodiment shown in FIG. 1 only schematically, the sintering grate 1 is provided with a suction box 2 provided below the sintering grate 1 and connected directly to the sintering grate 1. The suction box 2 is formed by walls 4 of the suction box extending from the side edges 3 of the sintering grate 1 downwards. connected air intake blower (not shown). The sintering grid 1 is connected at each side edge 3 with a storage element 5 lying approximately in the plane of the sintering grid 1, which is formed by a gas-permeable plate 6 on which the treated granular material 7 or the material 7 to be treated is approximately equal. as on sintering grid 1.

An upwardly extending side wall 10 is attached to each lateral edge 9 of the receiving element 5 and at least in the initial phase supports laterally the embankment of the material to be carried onto the sintering grid 1. As the material 7 proceeds, the shrinkage described above stabilizes and thereby to form a gap 11 on the side walls 10.

According to the embodiment shown in FIG. 2, the sintering grate is supported on the surrounding frame 12. This frame 12 carries laterally through outwardly extending support elements 5 through the frame 12, on whose outer edge 9 the side walls 10 protrude upward from the plane of the sintering grate 1.

Both the bearing element S and the side wall 10 can be protected by a thermal insulator.

In FIG. 3 shows a modified embodiment in which the frame carrier 13 of the sintering grid 1 is supported on a flange 14 of the shaft 12 projecting outwards. On this flange 14, a side wall 10 is fastened to the part 15 projecting through the receiving element 5, so that a distance A is formed between the side wall and the sintering grid. In the intermediate space thus formed, the bearing element 5 is fastened by means of bolts 16 which extend through the side wall 10 opposite the frame 12.

The sintering device according to the invention is applicable to all processes where the side effects, such as uneven penetration of the embankment at its edge, are to be eliminated or at least diminished when the grates are passed through the gas (inter alia in combustion pellets using a firing grate). for economic as well as environmental reasons.

In the sintering device according to the invention, the sintering grate may be formed in a variety of forms, such as having a grate car and a grate pan.

Industrial usability

The apparatus according to the invention is useful in the iron metallurgy for the preparation of fine-grain raw materials for blast furnace charging, and further for roasting by sintering sulphide raw materials or in the production of cement clinker.

Claims (5)

PATENT CLAIMS 1. Apparatus for the thermal treatment and / or gasification of granular materials, in particular for drying, burning and / or sintering fine-grained raw materials used in iron metallurgy, provided with a grate for storing the material to be treated, with a suction box located under the grate walls extending downwardly from the lateral edges of the grate and receiving elements permeable to gas and lying approximately in the plane of the grate and connected to the lateral edges of the grate, characterized by having side walls (10) extending from the grate (1) upwards, and these side walls (10) are connected to the outer edges (9) of the receiving elements (5). Device according to claim 1, characterized in that the bearing elements (5) are fixed in each case to one frame part (12) supporting the grate (1) and the side walls (10) are supported on the bearing elements (5). Device according to claim 1, characterized in that the side walls (10) are fixed in each case to one frame part (12), fastened by a flange to the shaft (4) carrying the grate (1), at a distance (A) from the grate ( 1), and the bearing elements (5) are inserted between the grate (1) and the side walls (10) and also freely fastened to the frame parts (12). Device according to claim 3, characterized in that the ends of the frame supports (13) supported on the grate (1) extend over the frame parts (12) and are covered or secured in their position by the bearing elements (5) or fixed with bolts (16). The device according to claims 1 to 4, characterized in that the width of one bearing element (5) is 10 to 35 cm and the connected side wall (10) protrudes approximately twice as high.