CN1067923A - The double-vessel iron ore direct reducing technology and the type of furnace - Google Patents

Abstract

The present invention relates to a kind of with the direct-reduction process sponge iron smelting technology and the type of furnace, adopt solid fuel and ore descending at the room of oneself respectively, the reverse relative movement mode that reducing gas is up, ore goes downwards to cooling room by chute with deadweight after reduction reaction becomes product, reducing gas is up by the breather hole on the chute, and body of heater is divided into upper and lower room two portions.The present technique device structure is simple, less investment, instant effect, saving of work and time, energy consumption is low, output is high, has suitable techno-economic effect, existing blast furnace is transformed with this technology then just can be produced the sponge iron product simultaneously, is worth promoting.

Description

The double-vessel iron ore direct reducing technology and the type of furnace

The invention belongs to direct method of reducing sponge iron smelting production technology, relate to a kind of new technology and the type of furnace.

Making steel-making without the long like this process of pit kiln, blast furnace and steel-making, and utilize iron ore direct reducing to become the technology of sponge iron, is metallurgist's hope for a long time.In recent years, this technology constantly develops, and especially fuel can use coal, natural gas etc. to replace under the expensive coke situation, and this technology more demonstrates great superiority.At present, " the movable bed method of shaft furnace ", " rotary kiln for directly reducing method " " fluidized bed process " " reactor fixed bed process " etc. are arranged in the technology with the direct-reduction process sponge iron smelting in the world, and I also proposed a kind of technology and the type of furnace (CN87103111) of new direct-reduction process sponge iron smelting in 1987.Produce sponge iron with above-mentioned technology and the type of furnace and generally obtained success commercial, also each has something to recommend him on technology and method, but also all exist some shortcoming, so that influence the development energetically of direct-reduction process sponge iron smelting.As " the movable bed method of shaft furnace ", the principle of this technology and the type of furnace is to utilize the relative movement of gas and object to carry out counter-current operation, when design, the reducing gas that has not utilized is recycled, thereby can obtain good utilization ratio, but this technology must be finished by two big operations, reducing gas producer and ore reduction stove promptly must be arranged, reducing gas is transformed with water vapor by natural gas, oxygen in carbide feed generator earlier, cuts and sends under hot 750-900 ℃ the temperature in the reduction furnace and the ferric oxide contact reacts.The device structure complexity of Yao Qiuing in addition, the sky hot gas price height of required usefulness, transportation inconvenience, problems such as reserves do not guarantee, the countries and regions that this technology is lacked for most of natural gas sources, obviously be inapplicable, with " rotary kiln for directly reducing method " sponge iron smelting technology, be with ore, reclaim coke, Wingdale (sweetening agent) is added in the rotary kiln from feed end together, the position suitable at whole kiln body controlledly blasts air, the body of heater material is heated to reduction temperature, this is a kind of quite attractive method, but because coal and ore mix in stove, the air quantity in each air port is unsuitable excessive, excessive air quantity can make air port place coal combustion produce high-temperature to cause ore be molten state, raw material is bonding mutually, forms furnace charge fault such as ring formation in stove, cause and produce not direct motion, simultaneously relatively poor aspect heat transfer rate and reaction efficiency, the volume ratio coefficient is lower, and the production unit of Electric furnace steel making is being arranged, because coal and product mix, from the saves energy angle, be difficult to cooperate hot charging steel-making, the energy consumption height, yield poorly, it is undesired to produce, and causes products production cost height, so also be difficult to apply." fluidized bed process " is on using, only be to be best bet to some fines iron ore, and for the overwhelming majority's general ore, can not impel reduction fully, the big portion of reduced iron is damp and hot simultaneously can't be reclaimed in practice, so its range of application is restricted." reactor fixed bed process " is that reducing gas Continuous Flow is successively crossed total system, and the special generation systems of reducing gas need be set by several reactions series connection mutually, and technological process is comparatively complicated, so this technology of widespread use is also comparatively difficult.According to above-mentioned several shortcomings of the prior art, I am once in the length of studying and use for reference each type of furnace, discard on the basis of its drawback, a kind of novel process and the type of furnace of sponge iron smelting have been conceived, promptly utilize the gas and the solid relative movement of shaft furnace, full contact, the characteristics that thermo-efficiency is high utilize rotary kiln to make the characteristics that fuel is made reductive agent again with coal, spirochete is adorned in employing in shaft furnace, make the stratified type of furnace of coal and fuel, this technology and body of heater and aforesaid shaft furnace are movable bed, rotary kiln, fluidized-bed and reactor fixed bed are compared, and have distinctive feature, double each length of getting, each is short to abandon it, through in the past few years facts have proved, is a kind of simple direct sponge iron smelting method.But also there is weak point in this type of furnace, with regard to each room of spirochete, coal and ore deposit respectively account for a half volume, compare with external shaft furnace is movable bed, raw material all is a raw ore in its volume, makes output have only half of shaft furnace output undoubtedly, in addition, the complex geometry of spirochete blade is given to make to process and is brought difficulty.

At the technology of No. 87103111 patents and the weak point of the type of furnace, the object of the present invention is to provide and a kind ofly can improve average furnace output, and reduce the novel direct sponge iron smelting technology and the type of furnace that makes type of furnace performance difficulty because of processing and manufacturing difficulty greatly.

Now design of the present invention and technical solution are described below:

The present invention still keeps solid fuel and ore descending, reducing gas rises, in shaft furnace, do relative movement, it is fully contacted, fully reduction, and, in the new type of furnace, be divided into two rooms in the body of heater still with the basic fundamental solution of elongation fuel and reductive agent, be upper chamber and lower chamber, upper chamber is the reduction chamber, and lower chamber is a gas generation room, is separated by a plurality of chutes between two rooms, a lot of breather holes littler than raw ore are arranged at the chute bottom, (seeing shown in Figure 3) can make the reducing gas of lower chamber pass through, reducing gas by breather hole after at first with each chute in raw ore fully contact, expand whole upper chamber then to, the mutual antikinesis of the raw ore of upper chamber and reducing gas makes its full contact, reacts completely.Chute bottom surface and body of heater vertical angle be less than 30 ° (seeing shown in Figure 2), and chute two sides refractory brickwork and vertical angle also intersect (seeing shown in Fig. 1,3) body of heater less than chute side in 30 ° of (seeing shown in Figure 4) stoves and bottom surface and be divided into two portions by chute group and chute group both sides refractory wall in the upper end.The starting material ore is delivered to furnace roof by skew bridge or rotary conveyor, enters into the stove superior part holding chamber behind upper and lower hopper, and coal is pushed to lower chamber (seeing shown in Fig. 1,2) from stove lower chamber top by screw propeller.For solving in the stove differential pressure problem with the external world, at Xia Meikou a plurality of envelope gas blanking machines are housed, its quantity decide according to the furnace volume size, passes through from descending the coal mouth to prevent furnace gas.After coal was pushed to the stove lower chamber, with the air combustion reaction that the place, air port sends to, its chemical equation was:

Coal and air combustion produce heat energy, and high temperature reduction gas enters stove top reduction room and raw ore contact reacts by the breather hole of chute bottom, and its chemical equation is:

In order to regulate stove lower coal and air combustion temperature, can be in right amount with entrained air part water vapor, or directly spray into from the high-temperature zone, so both can regulate furnace temperature, can obtain partial reduction gas again.About 900 ℃, the reducing gas and the furnace charge inverse motion of body of heater portion reduction room, preheating limit, limit reaction makes that raw material becomes metallic iron with iron oxide reduction in the stove under suitable temperature, then again with focusing under the closed state cooling room (see figure 2) outside chute mouth runs to stove certainly.Coal is slagging after stove bottom and air combustion, is discharged by residue extraction machine, and water is flushed in the slag bath under closed state.The product that cuts heat slips to the outer cooling room cooling of stove (see figure 1), and product is cooled to discharge by the discharge machine below 100 ℃ always, is transferred band and delivers to product library, and all these work all are continuous production processes.Cooperate electric furnace to carry out hot charging steel-making if cut hot product, then can reduce the power consumption of next procedure Electric furnace steel making, but should notice that product in loading and unloading, should reduce the chance that contacts with air in the transportation, in case reoxidation as far as possible.

According to the foregoing invention design, existing that furnace binding system accompanying drawings is as follows:

Fig. 1: double-vessel iron ore direct reducing technology synoptic diagram.

Fig. 2: reduction furnace structural representation.

Fig. 3: reduction furnace chute place schematic cross-section.

Fig. 4: chute assembly rotary expansion synoptic diagram.

Wherein:

1. rotary conveyor: give raw material on furnace roof and the outer coal look of reduction room, ore, coal are used.

2. the upper and lower hopper of furnace roof: transfer raw material usefulness, elevating hopper has the material level display unit, keeps material level, and works the gas effect of sealing.

3. body of heater: divide upper and lower two rooms, i.e. top reduction room and lower gas generation room.

4. chute assembly: each chute bottom is for being covered with the steel plate in ventilative sub-hole, and the chute both sides are the sloping core that refractory brick is built into, and the sectional view of its chute and rotary expansion figure are as shown in Figure 3, Figure 4.

5. coal hopper: store coal and use.

6. blanking machine: comprise the blanking machine of product cooling room bottom, play envelope gas blanking effect.

7. screw propeller: under closed state lump coal is pushed to bottom room in the stove continuously, requiring motor is stepless speed regulation, in the stove coal gas display unit should be arranged, and the principle of screw propeller is similar to brick press,

8. residue extraction machine: be contained in the bottommost of stove lower gas generation room, requiring motor is stepless speed regulation, discharges continuously according to the quantity of slag of product, and water is flushed in the slag bath under the situation of sealing.

9. product cooling room: be installed near body of heater and locate outward, its room communicates with chute mouth, and product reduction back runs to cooling room with deadweight, and generally two or three chutes share a cooling room, and the size of cooling room depends on reduction furnace volumetrical size.The product cooling is to utilize furnace roof to deliver to relative contact movement cooling with section hot product in the cooling room by the coal gas of high pressure positive blower pressurization after dedusting, washing.

10. residual heat using device: this is to utilize to cut hot product is run to the general stroke of cooling room by chute heat reclaim unit, utilize waste heat will manage the boiled generation steam of outer water, steam is ejected in the room of High Temperature Furnaces Heating Apparatus bottom again, plays a part to adjust furnace temperature and obtains hydrogen.

11. stock gas purifies: major equipment has gravitational precipitator, washing tower

12. cooled coal gas

13. air, water vapour

14. stock gas

15. ore conveyer belt

16. coal conveying belt

17. chute

18. chute both sides refractory brickwork

19. chute breather hole

20. coal inlet

The technology of the present invention and the type of furnace are compared with prior art, and less investment, instant effect, energy consumption is low, output is high, no matter are newly-built bodies of heater or use blast furnace reformation in addition, all can embody the unusual effect of its Technological Economy, should vigorously promote the use.

Claims (4)

1, a kind of direct-reduction process sponge iron smelting technology adopts solid fuel and ore descending, the reverse relative movement mode that reducing gas is up, make iron ore be reduced into sponge iron, it is characterized in that reducing gas is to produce, and up by the breather hole on the chute in the room of the bottom of body of heater; Raw ore is delivered to furnace roof by skew bridge or rotary conveyor, enters into the upper of furnace body room through upper and lower hopper, and after reduction reaction after a while, section hot product is descending with focusing on certainly under the closed state by chute; Residue water under closed state is flushed in the slag bath behind the coal combustion; The furnace roof cooled coal gas that cuts after the hot product utilization is pressurizeed carries out contact cooling at cooling room.

2, a kind of smelting system that designs according to the direct-reduction process sponge iron smelting technology described in the claim 1, it is characterized in that: total system is by body of heater, rotary conveyor, compositions such as hopper, coal hopper, screw propeller, residue extraction machine, product cooling room, residual heat using device, gravitational precipitator, washing tower up and down.

3, according to a kind of smelting system that designs according to direct-reduction process sponge iron smelting technology described in the claim 2, it is characterized in that: body of heater is divided into top reduction room and lower gas generation two portions; Stove is middle by separating less than 30 ° the chute assembly and the refractory brickwork group of chute both sides with the body of heater vertical angle; The chute bottom has the plurality of rows breather hole, and breather hole is less than the ore charge piece.

4, according to a kind of smelting system that designs according to direct-reduction process sponge iron smelting technology described in the claim 2, it is characterized in that: it is to be pushed in the stove with screw propeller that coal enters stove bottom room, at screw propulsion coal mouth multiple tracks blanking seal gas device is housed.

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