CN103033063B - Sinter fume exhaust heat recovering method - Google Patents

Abstract

The invention discloses a kind of sinter fume exhaust heat recovering method, comprise the steps: 1) open one or several bleeding point at ring cold cover top as the hot flue gas flue of bleeding; 2) inner along an axially horizontally disposed smoke deflector of central cooler at the cold cover of ring; 3) smoke deflector has the flow-guiding channel of certain width along central cooler center line; 4) preset one group of channel width, the flow field velocity that adopts SIMLPE can calculate in the cold cover of ring distributes, thereby obtains the flue gas mass flow that the cold cover of ring sucks, and repeatedly calculates, in the time that this flow equals the flue gas mass flow of sintering deposit release, set definite value is the channel width of requirement. The present invention can absorb the hot flue gas of central cooler to greatest extent equably, has avoided the discharge of the hot flue gas of part, has promoted flue-gas temperature, has improved the rate of recovery of fume afterheat.

Description

Sinter fume exhaust heat recovering method

Technical field

The present invention relates to field of iron and steel smelting, especially a kind of sinter fume exhaust heat recovering method.

Background technology

SINTERING PRODUCTION is an indispensable important step during whole steel and iron industry is produced, and produces at presentExtensively adopt strand exhaust sintering machine, capital equipment has sintering machine, air exhauster, single roll crusher, ring coldMachine (belt-cooling machine), adhesive tape conveyor etc. Sintering process is mainly divided into sintering and cooling two parts: 1. ore depositThing powder (iron-bearing material, solvent, fuel etc.) batching forms thermal sintering cake on sintering machine after burning,2. after the fragmentation of thermal sintering cake, the bed of material cools on central cooler, and sintering deposit material temperature degree is by 800 ~ 1000 DEG CBe down to 120 DEG C of left and right, send into adhesive tape conveyor.

In sintering process, in sintering feed, amount of heat is emitted in fuel combustion, and a part makes bed of material MineralsProduce melting, flue gas a part of that aspirated by air exhauster is taken away; In cooling procedure, cold wind is cold from encirclingMachine bottom blasts, and by bed of material cooling, produces a large amount of sinter fumes. To this two parts sinter fume waste heat(comprising sintering device flue gas waste heat and central cooler fume afterheat), the overwhelming majority is diffused by chimney at present,Reasonably do not utilized, wasted a large amount of thermals source. In recent years, how to utilize this part waste heat moreMore paid attention to, the sintering waste heat that has part steel mill starts to recycle generating, wherein central cooler portionThe flue gas of point leading portion due to its temperature higher (can reach more than 350 DEG C) and fly ash content lower, haveHigh recycling is worth.

Because central cooler is longer, and from sintering deposit blanking port (initiating terminal) to discharging opening (end), burnKnot ore deposit temperature is reduced to 120 DEG C of left and right from 800 DEG C ~ 1000 DEG C, and flue-gas temperature correspondingly reduces (from 500 DEG CLeft and right is reduced to 50 DEG C of left and right). At present in limited central cooler flue gas heat recovery, substantiallyBe to open one or several bleeding point on the cold cover of the original ring of central cooler front end, flue gas introduced to waste heat boiler and produceRaw steam or generating. Owing to having gap between the cold cover of ring and circular cooler trolley, and very difficult sealing (encircles cold coverBe static, and central cooler moves), this must cause each bleeding point sucking the same of hot flue gasTime also suck a large amount of cool exterior air, reduced the quality of flue gas; Hot flue gas between bleeding pointEmit outward along gap, cause the heat of this part flue gas to lose in vain.

Summary of the invention

The problem existing for prior art, the object of the present invention is to provide a kind of sinter fume waste heat to returnReceiving method, it can improve the flue-gas temperature of bleeding point effectively, promotes flue gas quality, increases substantially burningThe rate of recovery of knot fume afterheat.

For achieving the above object, sinter fume exhaust heat recovering method of the present invention, is specially:

1) open one or several bleeding point at ring cold cover top as the hot flue gas flue of bleeding;

2) inner along an axially horizontally disposed smoke deflector of central cooler at the cold cover of ring;

3) middle part of smoke deflector has the flow-guiding channel of setting width along the direction of central cooler center line;

4) establish d_xFor the channel width at flow-guiding channel x place, d_xCalculate by following method:

u_j(x,h,z)＝f(G₀(x)，d_x，D，h，H，L)（1）

$G\left(x\right)=2\underset{0}{\overset{d_x/2}{\∫}}\mathrm{\ρ}(x,h,z)u_j(x,h,z)\mathrm{dz}---\left(2\right)$

G₀(x)＝ρ₀W₀×(1-η)/L（3）

Wherein, d_xFor the channel width at x place, D is the cold cover width of ring (circular cooler trolley width), and h isSmoke deflector is apart from the height on edge on chassis, and H is the height on edge on the cold cover distance from top chassis of ring, LFor encircling cold cover length, W₀For encircling total cooling air quantity in cold cover, η is central cooler air leakage coefficient.

Further, above described smoke deflector, being provided with the fly ash granule preventing in flue gas is deposited on and leadsDust block board on stream plate.

Further, the inwall of the top of described dust block board and the cold cover of described ring is welded and fixed, under dust block boardThe top of portion and described smoke deflector is welded and fixed, and the angle between dust block board and smoke deflector is 30Degree～60 degree.

Feature of the present invention is by arrange smoke deflector and dust block board in the cold cover of ring. At known sinteringUnder the operating mode of mineral products amount, can determine the maximum stream flow of recyclable sinter fume, determine on the cold cover of ring and bleedBehind the position of mouth, utilize SIMPLE algorithm to solve N-S equation, can calculate flue gas water conservancy diversionPlate is at the flow-guiding channel of diverse location, thereby can absorb to greatest extent the hot flue gas of central cooler, avoidsThe discharge of the hot flue gas of part, promoted flue-gas temperature, improved the rate of recovery of fume afterheat.

Brief description of the drawings

Fig. 1 is apparatus structure schematic diagram of the present invention;

Fig. 2 be in Fig. 1 A-A to schematic cross-section;

Fig. 3 is that the x-y of computational fields is to figure;

Fig. 4 is that the y-z of computational fields is to figure;

Fig. 5 is diversion outlet motion pattern one;

Fig. 6 is diversion outlet motion pattern two;

Fig. 7 is diversion outlet motion pattern three;

Fig. 8 is the speed vector figure of a certain cross section;

Fig. 9 is the structural representation of smoke deflector;

Figure 10 is the flue gas mass flow distribution figure before transformation;

Figure 11 is the flue gas mass flow distribution figure adopting after the present invention.

Detailed description of the invention

Below, with reference to accompanying drawing, the present invention is more fully illustrated, shown in the drawings of of the present inventionExemplary embodiment. But the present invention can be presented as multiple multi-form, and should not be construed as limitationIn the exemplary embodiment of narrating here. But, these embodiment are provided, thus make the present invention comprehensively andComplete, and scope of the present invention is fully conveyed to those of ordinary skill in the art.

For ease of explanation, here can use such as " on ", the space phase such as D score " left side " " right side "To term, the pass for element shown in key diagram or feature with respect to another element or featureSystem. It should be understood that except the orientation shown in figure, spatial terminology is intended to comprise that device existsDifferent azimuth in use or operation. For example, if the device in figure is squeezed, is stated as and is positioned at itThe element of his element or feature D score will be positioned at other elements or feature " on ". Therefore, exemplaryTerm D score can comprise upper and lower orientation both. Device can otherwise be located (rotation 90Spend or be positioned at other orientation), the relative explanation in space used here can correspondingly be explained.

As shown in Figure 1 and Figure 2, sinter fume exhaust heat recovering method of the present invention, cold for reclaiming sintered ringThe fume afterheat of machine, specifically comprises:

A kind of sinter fume exhaust heat recovering method of the present invention, is specially:

1) open one or several bleeding point at ring cold cover top as the hot flue gas flue of bleeding;

2) inner along an axially horizontally disposed smoke deflector of central cooler at the cold cover of ring;

3) middle part of smoke deflector has the flow-guiding channel of setting width along the direction of central cooler center line;

4) establish d_xFor the channel width at flow-guiding channel x place, d_xCan calculate by following method:

u_j(x,h,z)=f(G₀(x)，d_x，D，h，H，L)（1）

$G\left(x\right)=2\underset{0}{\overset{d_x/2}{\∫}}\mathrm{\ρ}(x,h,z)u_j(x,h,z)\mathrm{dz}---\left(2\right)$

G₀(x)＝ρ₀W₀×(1-η)/L（3）

Wherein, d_xFor the channel width at x place, D is the cold cover width of ring (circular cooler trolley width), and h isSmoke deflector is apart from the height on edge on chassis, and H is the height on edge on the cold cover distance from top chassis of ring, and L isEncircle cold cover length, W₀For encircling total cooling air quantity in cold cover, η is central cooler air leakage coefficient.

Formula (1) is after the flow field shown in Fig. 3, Fig. 4 is solved, on cross section, x place in y directionThe one of velocity component is simplified expression, and formula (2) represents the flue gas mass flow that the x place cold cover of ring sucks, formula(3) represent the flue gas mass flow that x place sintering deposit discharges.

Due to D, h, H, L, G₀(x) be all definite value, therefore, u_j(x, h, z) only depends on d_xVariation,That is setting initial value d_x(x=0, L), adopts SIMLPE algorithm can calculate u_j(x, h, z), thus canTo determine G (x). Relatively G (x) and G₀(x), as G (x)=G₀(x) time, setting value d now_x(x=0，L)Be desired channel width.

Because central cooler radius is larger, for convenience of calculation, can be by central cooler center in certain lengthLine is reduced to straight line, and computational fields is shown in Fig. 3, Fig. 4. Under normal operating condition, the flue gas on central coolerFlow field can be regarded constant flow field approx as, and flow velocity is very low, for incompressible flow, therefore this flow canTo describe intuitively with streamline ψ. The in the situation that of adding deflector in petticoat pipe, on the cross section at x place,Flow field distributes axisymmetricly, and to diversion outlet, the streamline of ψ=const is confocal hyperbola, as Fig. 5,Shown in Fig. 6, Fig. 7.

From Fig. 5, Fig. 6, Fig. 7, install additional after deflector, on the cross section at x place, flue gas flow fieldThere are three kinds of forms: (1) all enters petticoat pipe through sintering deposit hot flue gas out through flow-guiding channel, withTime part atmosphere cold air also enter petticoat pipe by flow-guiding channel, also herein, petticoat pipe had both sucked hot cigaretteGas, has also sucked cold air, has reduced the flue-gas temperature in petticoat pipe, and the form of streamline ψ as shown in Figure 5;(2) enter petticoat pipe through a sintering deposit hot flue gas part out through flow-guiding channel, a part is from chassisDischarge with the gap place of petticoat pipe, herein, petticoat pipe could not absorb sintering deposit hot flue gas out completely,Wasted partial heat energy, the form of streamline ψ as shown in Figure 7; (3) through sintering deposit hot flue gas outAll enter petticoat pipe through flow-guiding channel, both entered petticoat pipe without atmosphere cold air by flow-guiding channel, hot flue gas alsoDo not discharge from the gap of chassis and petticoat pipe, also herein, petticoat pipe all and has only absorbed hot flue gas,The form of streamline ψ as shown in Figure 6. The technical essential that the application proposes is the design by deflector,Flue gas flow field reaches form as shown in Figure 6.

In order to reach above-mentioned effect, must determine deflector channel width d_x，d_xConcrete computational process is as follows:

Computational fields is shown in that, shown in Fig. 3, Fig. 4, flue gas flow rate is very low in flow field, flows for incompressible,This flows and can describe with following Navier-Stokes equation:

$\frac{\∂\left({\mathrm{\ρu}}_j\right)}{{\∂x}_j}=0$

$\frac{\∂\left({\mathrm{\ρu}}_i{u}_j\right)}{\∂x_j}=\frac{{\∂\mathrm{\π}}_{\mathrm{ij}}}{{\∂x}_j}$

Wherein: π_ij＝-pδ_ij+τ_ij

${\mathrm{\τ}}_{\mathrm{ij}}=\mathrm{\μ}(\frac{{\∂u}_i}{{\∂x}_j}+\frac{{\∂u}_j}{{\∂x}_i})-\frac{2}{3}\mathrm{\μ}\frac{{\∂u}_k}{{\∂x}_k}$

In above-mentioned equation, ρ is density, u_i、u_j、u_kBe respectively the speed in three directions of x, y, zComponent, p is pressure, μ is viscosity, δ_ijFor operation coefficient (when i=j, δ_ij=1; When i ≠ j, δ_ij＝0）。

At given boundary condition (d_x, D, h, H, L), and known primary condition (outgoing quality streamAmount G₀, and inlet pressure P₀) situation under, to above-mentioned N-S equation, adopt SIMPLE algorithm,The flow field velocity that can obtain whole computational fields distributes. Wherein, d_xFor the channel width at x place, D is cold for encirclingMachine trolley width, h is the height of smoke deflector apart from edge on chassis, and H is the cold cover height of ring, and L isEncircle cold cover length; Outgoing quality flow G₀Be the total flow of absorbed sinter fume, can be by ringTotal cooling air quantity W in cold cover₀η obtains with central cooler air leakage coefficient, i.e. G₀＝ρ₀W₀× (1-η), inlet-pressurePower P₀It is atmospheric pressure.

Obtaining after flow field velocity distribution, the flue gas mass flow sucking at the x place cold cover of ring is

$G\left(x\right)=2\underset{0}{\overset{d_x/2}{\∫}}\mathrm{\ρ}(x,h,z)u_j(x,h,z)\mathrm{dz}.$

Because sintering deposit form in cooling procedure is almost constant, porosity is constant, therefore can think,Flue gas mass flow is equal everywhere along central cooler length direction, therefore, and the cigarette discharging at x place sintering depositGas mass flow can be expressed as G₀(x)＝ρ₀W₀×(1-η)/L。

In boundary condition and primary condition, D, h, H, L, G₀、P₀All known conditions, onlyThere is d_xNeed to set. Preset one group of d_x(x=0, L), can calculate whole flow field velocity and distribute,Thereby determine G (x). If G (x) > G₀(x), encircle the flue gas mass flow that cold cover sucks and be greater than sintering depositThe flue gas mass flow discharging, illustrates that encircling herein cold cover has sucked cold air, shows d_xBigger than normal; IfG(x)<G₀(x), the flue gas mass flow of encircling cold cover suction is less than the flue gas mass flow that sintering deposit discharges,The gap discharge of a sintering deposit hot flue gas part out from chassis and petticoat pipe is described, shows d_xLess than normal;Revise channel width d_x(x=0, L), adopt SIMPLE algorithm again, and secondary is obtained whole computational fieldsFlow field velocity distributes, relatively G (x) and G₀(x), if G (x) ≠ G₀(x), again revise channel widthd_x(x=0, L), calculates, repeatedly until G (x)=G₀(x), encircle flue gas mass flow that cold cover sucks etc.The flue gas mass flow discharging in sintering deposit, sintering deposit hot flue gas out all enters cigarette through flow-guiding channelCover, both entered petticoat pipe without atmosphere cold air by flow-guiding channel, and hot flue gas does not have the seam from chassis and petticoat pipe yetGap place discharges, and also herein, petticoat pipe all and has only absorbed hot flue gas, sees Fig. 8, d now_x?For desired channel width, Fig. 9 is shown in by deflector structure schematic diagram.

The device adopting in sinter fume exhaust heat recovering method of the present invention comprises circular cooler trolley 1, it is cold to encircleCover 2, smoke deflector 3, dust block board 4, supporting traverse 5, bleeding point 6.

The upper front end of circular cooler trolley 1 is provided with the cold cover 2 of ring for collecting flue gas, encircles cold cover 2Top is provided with the bleeding point 6 being connected with flue, and encircle in cold cover 2 and be horizontally disposed with smoke deflector 3,The edge of smoke deflector 3 is welded and fixed with the inner side of the cold cover 2 of ring, and the middle part of smoke deflector 3 is along itLength direction is provided with the flow-guiding channel 7 of setting width.

The top of smoke deflector 3 is provided with dust block board 4, in the top of dust block board 4 and the cold cover 2 of ringWall is welded and fixed, and the top of the bottom of dust block board 4 and smoke deflector 3 is welded and fixed, dust block board 4 withThe angle arranging between smoke deflector 3 is 30 degree～60 degree. Fly ash granule in flue gas is fallen like thisDust block board 4 landings of postponing behind smoke deflector 3 tops, thus ensure that the fly ash granule in flue gas is heavyAmass on smoke deflector 3.

The bottom of smoke deflector 3 is provided with supporting traverse 5, and supporting traverse 5 is for supporting flue gas water conservancy diversionPlate 3 and dust block board 4, supporting traverse 5 is round steel pipe or square steel tube, its two ends are directly weldingly fixed on ringCold cover 2 outer walls, and can be used as ventilation beam.

Sintering deposit falls into after circular cooler trolley 1, and the cold air blasting from the bottom of circular cooler trolley 1 is to burningKnot ore deposit is carried out cooling, produces the flue gas of 500 ~ 50 DEG C of temperature, and it is cold that wherein more than 350 DEG C flue gases enters ringThe cold cover 2 of ring of machine upper front end, enters flue by the bleeding point 6 that encircles cold cover 2 tops, can be used for producingHeat-dissipating water or steam, to carry out secondary utilization.

Sinter fume exhaust heat recovering method of the present invention, by arranging smoke deflector and gear ash in the cold cover of ringPlate, according to total cooling air quantity and central cooler air leakage coefficient in the cold cover of ring, can draw flue gas flow, and thenDetermine the width of the flow-guiding channel of smoke deflector according to the aperture position of bleeding point, can be to greatest extentAbsorb the hot flue gas of central cooler sintering deposit, avoided the discharge of the hot flue gas of part, improved fume afterheatThe rate of recovery. The present invention, by technological transformation, has reduced environmental pollution, has improved heat secondary utilization rate.

Figure 10 is the flue gas mass flow distribution figure before certain steel mill's ring cold machine smoke hood transformation, and Figure 11 is for adoptingFlue gas mass flow distribution figure after the present invention. Can find out, adopt after this method, along central cooler platformThe flue gas mass flow of car is substantially even, has reached the effect of aspirating equably hot flue gas.

Claims (3)

1. sinter fume exhaust heat recovering method, is characterized in that, the method is specially:

1) open one or several bleeding point at ring cold cover top as the hot flue gas flue of bleeding;

2) inner along an axially horizontally disposed smoke deflector of central cooler at the cold cover of ring;

3) middle part of smoke deflector has the flow-guiding channel of setting width along the direction of central cooler center line;

4) establish d_xFor the channel width at flow-guiding channel x place, d_xCalculate by following method:

u_j(x,h,z)＝f(G₀(x)，d_x，D，h，H，L)(1)

$G\left(x\right)=2\underset{0}{\overset{d_x/2}{\&Integral;}}\mathrm{\&rho;}(x,h,z)u_j(x,h,z)dz---\left(2\right)$

G₀(x)＝ρ₀W₀×(1-η)/L(3)

Wherein, d_xFor the channel width at x place, D is the cold cover width of ring, and h is that smoke deflector is apart from chassisThe height on upper edge, H is the height on edge on the cold cover distance from top chassis of ring, L is the cold cover length of ring, W₀ForEncircle total cooling air quantity in cold cover, η is central cooler air leakage coefficient, G₀(x) be the cigarette discharging at x place sintering depositGas mass flow, G (x) is the flue gas mass flow sucking at the x place cold cover of ring.

2. sinter fume exhaust heat recovering method as claimed in claim 1, is characterized in that, at described flue gasDeflector top is provided with the fly ash granule preventing in flue gas and is deposited on the dust block board on deflector.

3. sinter fume exhaust heat recovering method as claimed in claim 2, is characterized in that, described dust block boardTop and the inwall of the cold cover of described ring be welded and fixed, the bottom of dust block board and described smoke deflector upperPortion is welded and fixed, and the angle between dust block board and smoke deflector is 30 degree～60 degree.