DE1178869B - Plant and process for the production of iron sponge from lump ore or agglomerates - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C 21b

Number: File number: Registration date: Display day:

German class: 18 a -13/00

H 37987 VI a / 18 a November 27, 1959 October 1, 1964

Plants for the production of sponge iron from lump ore or agglomerates are in different Embodiments known. In their basic structure, they consist of a device for Generation of a reducing gas, mostly from hydrocarbons, a reduction room and downstream regenerative heat exchangers. The lump ores or agglomerates are in the reduction room with the reducing gases at temperatures of 700 to 1000 ° C without melting Reduced sponge iron. This does not generally cause any difficulties in terms of reduction technology. at the known systems, however, is the cost of energy and fuel for heating or the Production of the reducing gases considerable. In fact, there is mostly a continuous movement in the Lump ores or agglomerates through a shaft-shaped reduction chamber in countercurrent required to a stream of preheated reducing gases. Even in the most favorable of circumstances, it can here only about a quarter of the reducing gas can be used with each pass. It is therefore necessary and usual to cool the escaping gases and remove the reduction products before the unused parts of the reducing gas recovered and again for further circulation heated to about 1000 ° C. As a result, the gases that leave the reduction zone and the Heated reduction products lost large amounts of heat through radiation, albeit a part of this Gases are often recovered, the losses are still considerable. This applies, for example for a device which is characterized by a vertical, generally circular, Reduction space divided into a melting zone and a reduction zone, one with these through connected to a cracked gas channel, expediently arranged next to the reduction chamber at the level of the melting zone Gap space and an exhaust gas recirculation duct between the upper end of the reduction space and the melting zone. This also applies if the gap is in the masonry of the reduction room is arranged and surrounds it in a ring.

To work more economically, ratios are 4-5 moderately complicated measures have been proposed. In particular, it is known to have a shaft-shaped To use a reduction room and two separate, independent gas circuits, one of which is mainly used for reduction and the other primarily for heat transport. Here one works with a relatively small system and process for the production of sponge iron from lump ore or agglomerates

Applicant:

Hüttenwerk Oberhausen Aktiengesellschaft, Oberhausen (RhId.), Essener Str. 66

Named as inventor:

Dr.-Ing. Ludwig von Bogdandy, Essen-Frintrop

Reduction zone in which the preheated lump ores or agglomerates remain for a certain period of time. Freshly prepared and preheated gas then only goes through the reduction zone and becomes instantaneous then removed and passed to a device, the high temperature heat for a short time can save effectively. If you work with two such devices that can store the heat, thus the flow of the heated gas can be repeatedly reversed so that the piece Lz or the Agglomerates are reduced in the reduction zone from top to bottom and from bottom to top can. When the reduction is complete, this gas cycle is shut off and the solid parts sink inside the reduction room by removing the cooled one located in the lower part of the shaft Metal sponge down. This causes hot reduced metal to fall in from the reduction zone down a cooling zone and is replaced from above by a preheated feed. It will then new ores or agglomerates are added to the top of the shaft-shaped reduction room, and a second gas cycle is initiated. For this purpose, cooling gas is fed vertically from the bottom up through the Shaft and then passed out to a gas container. This measure is intended to increase the heat content of the hot metal at the bottom of the shaft up to the upper part, which is with was charged to the cold lump ore or agglomerates. The hot gases also go in and through the reduction zone and then up the shaft-shaped reduction space to the To raise the temperature in the reduction zone to the desired level and around part of the ore in the Preheat the shaft above the reduction zone.

409 689/213

I 178 869

The preheated lump ores or agglomerates are then in the reduction zone and are for Reduction by the preheated gas ready. By flowing through the heat accumulator new reducing gas is preheated and fed directly into the reduction zone of the shaft-shaped reduction space. The hot gases are immediate withdrawn after passing through the reduction zone and then go to a second heat input reflects the simplicity of the system according to the invention. In addition, according to the invention, the Regenerator chambers at the same time cracking furnaces for the generation of the reducing gas from freshly imported Hydrocarbons, so that according to the invention between the reduction furnace and the regenerative Gas splitters an optimal thermal network is created.

Such are the advantages achieved by the invention

Storage. The gases, which are summarized by passing through the io mainly in the essential Ver-heat storage have cooled down, contain the improvement in the heat economy, especially since they are consumed Parts of the reducing gas and, according to the invention, with regard to the heat flow equal to water vapor and any carbon dioxide realized in the sam a closed circuit where reduction zone was formed. These products are, on the one hand, the transformation reactions and andden removed, and excess reducing gases 15 on the other hand the reduction in an advantageous manner in these go to a gas tank for further circulation. Heat cycle are included and only ver-complementary gas is added to the system and the required heat is added again. Reducing gases are returned to the plant. In the following, the invention is based on a

pumps. - All of this is obviously complex. only one embodiment illustrative schematic

The invention has set itself the task of explaining a 20 matic sketch in more detail. Plant and a method for producing According to the sketch, there is one according to the invention

Sponge iron from lump ore or agglomerates to add system of two primary converters 1 and 1 α for the, in which or in which between the reducing hydrocarbon-containing gas (ζ. B. natural gas) or oil, tion room and the device for generating one of the over the line 4 alternately in 1 and 1 α ge reducing gas a functional and heat-hosted 25 conducts and there with forming agents, such as. B. Association is created. Steam, carbonic acid, O ₂ or these substances -

The invention relates to a plant for the production of the gases (through line 5), already partially converted to CO by sponge iron from lump ore or agglomerates and H ₂ , with downstream activated, consisting of a device for generating secondary secondary converters 2 and 2 a, which equal to a reducing gas made of hydrocarbons, which at 3 ° give off heat to the reduction chamber flowing in from 1 or la and the downstream regenerative gas mixture and cause that with 6 heat exchangers. The invention consists in
that the regenerative heat exchanger at the same time as
Cracking furnaces for the hydrocarbons to be converted
trained and alternating with combustion. 35
the partially consumed reduction exhaust gases withdrawn from the reduction chamber can be heated with air or oxygen. According to a preferred embodiment of the invention, these are regenerative
Heat exchangers designed as secondary cracking furnaces 40 reactors, where the still contained therein burns and combined with upstream primary cracking equipment with air and / or O ₂ for the purpose of agitation. In the structural design consists
now the possibility of the reduction room and the
regenerative heat exchanger, optionally with
the upstream primary cracking furnaces, one into the other 45
boxes, whereby the regenerative ones are expedient
Heat exchanger surround the reduction reactor like a jacket.

The system according to the invention can easily be operated so that the reducing gases in the regenerative heat exchangers is brought to a temperature of over 1000 ° C, with the Forming means, e.g. B. oxygen, air, steam, carbon dioxide, mixed in such a ratio and on the hydrocarbons to be converted, so that the entire reduction

or 6 a exiting gas mixture contains predominantly CO and H ₂ and only a little CO ₂ , H ₂ O and hydrocarbons and has a temperature of> 1000 ° C. The CO: H ₂ mixture emerging from 6 or 6 a enters the reduction vessel 3 at 7 and meets the ore to be reduced there. After the reaction has taken place, the gas leaves the reduction vessel at 8 and re-enters at 9 or 9 a be partially or completely burned in the secondary heating of the heat accumulator. The air is introduced at 10 or 10 a.

The shut-off devices provided in the lines are switched alternately as follows:

tion gases can be burned in the regenerative heat exchanger to be heated. So According to the invention, there is no recirculation of the reducing gas to the extent that it is after Passing through the reduction space containing the ore to be reduced is mainly a post-shredded space Regenerator is fed to be burned in this and to heat it. That about in addition, an excess part of the reducing gas can possibly be circulated irrelevant. The result is a considerable procedural simplification, which also results

Period a

Valves 11, 12, 13, 14, 15, 16 open, Valves 11a, 12 a, 13 a, 14 a, 15 a, 16 a closed.

Gas or oil and reforming agent from lines 4 and 5 flow into the primary and secondary _{reactors 1 and 2, where they are converted into CO: H 2} mixtures of> 1000 ° C, which reduce the ore in reactor 3. The reduction exhaust gas, which still contains CO + H ₂ , then flows into the heat accumulator 2 α and is burned there. The exhaust gas escapes through chimney 17.

Period b

Valves 11a, 12a, 13a, 14a, 15a, 16a open, valves 11, 12, 13, 14, 15, 16 closed.

According to the invention, the reforming agents O ₂ , air and steam are preferably mixed in a ratio such that the entire reduction exhaust gas can be burned in the heat storage device. His warmth

content is then used to break down steam into hydrogen, for example after the reaction

CH ₄ + H ₂ O = CO + 3 H ₂ ,

exploited, for which 49.3 kcal / mole are consumed. Contrary to the reaction

CH ₄ + V ₂ O ₂ -CO + 2 H ₂ ,

which is exothermic at 8.5 kcal / mole. With this procedure, the exhaust gas does not contain any calorific value more, so that all technical difficulties associated with exhaust gas recycling are eliminated. the sensible heat of the exhaust gas escaping at 17 or 17 a can be used to prevent the entering Preheat gases.

In the described system, it is possible the reduction reactor 3 and the surrounding converters 2, la with the associated primary converters 1, la, as it ineinanderzuschachteln, wherein suitably the transducers 2, 2 surrounded coat a manner the reduction reactor. 3 In this way you get a system of very compact design, which is also favorable for the heat economy, since the outer surfaces, where heat losses can occur, are small.

Claims (4)

Patent claims: 1. Plant for the production of sponge iron from lump ore or agglomerates, consisting of a device for generating a reducing gas from hydrocarbons, a reduction chamber and downstream regenerative heat exchangers, characterized in that the regenerative heat exchangers (2, 2a) also act as cracking furnaces for the hydrocarbons to be formed and can be heated with air or oxygen in alternating cycles by burning the partially consumed reduction exhaust gases withdrawn from the reduction chamber (3). 2. Plant according to claim 1, characterized in that the regenerative heat exchangers (2, 2a) are designed as secondary cracking furnaces and are combined with upstream primary cracking devices (1, la) . 3. Plant according to claims 1 and 2, characterized in that the reduction chamber (3) and the regenerative heat exchangers (2, 2 a) optionally with the upstream primary cracking furnaces (1, la) are nested and the regenerative heat exchangers (2, 2 a ) surround the reduction space (3) like a jacket. 4. The method for operating the system according to claim 1 to 3, characterized in that the reducing gases in the regenerative heat exchanger brought to a temperature of over 100O ⁰ C and that the forming means, for. B. oxygen, air, steam, carbon dioxide, mixed in such a ratio and switched to the hydrocarbons to be converted that the entire reduction exhaust gases can be burned in the heat exchanger to be heated. Considered publications:
German Patent No. 1,033,902;
German explanatory documents No. 1 046 327,
419 1 sheet of drawings 409 689/213 9.64 ® Bundesdruckerei Berlin