JPS61250119A - Operating method for sintering - Google Patents

Abstract

PURPOSE:To improve the productivity of sintered ore and to stabilize quantity by adjusting moisture, the suction force of a main exhauster, etc., so that the predicted value of a combustion rate based on the moisture, etc., of a sintering raw material and the voids of the packed layer in the stage of charging to a pallet of a sintering machine coincides with a target value. CONSTITUTION:The raw material apparent dry density rho, grain size (d), grain size dispersion measure Sd and water absorptivity x0 of an arithmetic unit 10 based on the raw material in a raw material tank 1 and the initial moisture content x3 of the raw material, the raw material temp. T1 in a surge hopper 3 and moisture content x4 of an arithmetic unit 20 based on the water added in a mixer 2, etc., are inputted to a combustion rate control device 19. The voids of the packed layer 9 in the stage of charging to the pallet 6 of the sintering machine, the height of the packed layer 9 and the suction force of the main exhauster 8 are also inputted thereto and the combustion rate of the raw material prior to charging to the pallet is predicted. The following terms are respectively selected and controlled in such a manner that the predicted value coincides with the target value Vfo: The moisture of the raw material is adjusted by an added moisture detector 11, the charging bulk height by a charging bulk height controller 12, the packed layer height by a packed layer 9 height detecting and adjusting device 13 and the suction force of the main exhauster 8 by a suction pressure controller 15.

Description

[Detailed description of the invention] Industrial application field This invention relates to a sintering operation method using a DL type sintering machine,
In particular, it relates to sintering operation methods for improving the productivity and stabilizing the quality of sintered ore.

Conventional technology and its problems As a method for improving the productivity and stabilizing the quality of sintered ore in sintering operations, for example, the porosity of the packed bed when charging the sintering machine pallet, the particle size dispersion of the sintering raw material, etc. A method is known in which the air permeability of a packed bed is stabilized based on this calculation (Japanese Patent Laid-Open No. 58-221238). However, the air permeability of the packed bed is greatly affected by the porosity of the packed bed after moisture condensation, which changes depending on the temperature and moisture of the sintered raw material, and also because the influence of the air permeability of the raw material is not taken into account. Control accuracy is far from sufficient.

In addition, the moisture content added to the sintering raw material when charging the sintering machine pallet is determined from the raw material particle size, raw material water absorption rate, etc., the raw material air permeability is calculated based on this, and the tweed forward control is based on this value. A method of stabilizing the air permeability of a packed bed by performing the following is known (Japanese Patent Laid-Open No. 58-217644). This method is preferable to the above method in that it takes into account the influence of raw material air permeability. However, since this method does not take into account the porosity of the packed bed at the time of loading the pallet, which is closely related to the air permeability of the packed bed, it cannot be said that the effect of improving control accuracy is sufficient.

Purpose of the Invention The present invention has been made in consideration of the above-mentioned conventional circumstances, and an object thereof is to propose a sintering operation method that can further improve controllability.

Structure of the Invention The sintering operation method according to the present invention is based on the air permeability, temperature, moisture content, and dry apparent density of the sintering raw material determined in advance, as well as the porosity of the packed bed, the height of the packed bed, and Main exhaust air 1
The combustion rate is predicted based on the suction force, and the moisture content of the sintering raw material and/or
Alternatively, it is characterized by adjusting the charging bulk and/or the filling bed height and/or the suction force of the main exhaust fan.

The method of this invention will be explained in detail below.

The combustion speed (combustion front descending speed) is approximately proportional to the wind speed passing through the packed bed, and can be approximated by the following equation (1).

71st Officer C1・U・・・・・・・・・・
・・・・・・(1) vf: Combustion speed (m/m1n) U: Packed bed passing wind speed (m/min) C1: Combustion front grade attainment position from coefficient ignition furnace (hereinafter referred to as rFFPJ)
) is V7. Assuming that U is constant and ignoring the moisture in the gas sucked by the main exhaust fan, the moisture balance equation shown in equation (2) below holds true.

Psml: Apparent density of packed bed at the time of loading on pallet (1v/
(g) x: Moisture content of raw material (wt%) at the time of pallet charging h:
Packed bed height <m> ρg = gas density (rostrum/g) Wg: moisture in exhaust gas (doff gas) (ke/kf) Assuming that the moisture in the exhaust gas Wg is saturated, it is expressed by the following equation (3).

P*Pw: Total pressure and saturated vapor pressure (kt/d'') Further, the relationship between the saturated vapor pressure Pw and temperature is expressed by the following equation (4), for example, from the steam table.

T: Moisture #Temperature of the raw material gas for diameter reduction ('C) The temperature of the raw material gas after moisture condensation, T, can be calculated from the following equation (6), assuming that all the heat of moisture condensation is used to trap the temperature rise of the raw material. can.

Cs(ρSBl"T'j"'J'S!11 j 'r,
)=(-jHw)・(/'Smfi @--Pstl
・” ) “”” = (5) C5: Specific heat of sintering raw material (kcal/kf'c) T,: Raw material temperature at the time of pallet charging ('C) ρIm! : Apparent density of packed bed after water condensation (kqlrd) z6: Raw material water content after water condensation (wt%) (-jHw)
: Heat of condensation of water (kcaJ?A) Assuming that there is no volume change in the entire packed bed and water fills the voids, the following (6) ~
The αQ formula holds true.

PmyH=p, ・(1−ε+) −−−
----------(7)/'1m! = p, ・(
1-1) ""-" (8) p: Dry apparent density of sintered raw material (kf/m') C7: Predicted value of porosity of packed bed at the time of pallet charging (-) C!: After moisture condensation Packed bed porosity predicted value (-) Also, the packed bed passing wind speed U in the above (1) 2 is determined by the following equation (2).

Q: Air flow rate passing through packed bed (frI/min) A: Filled bed suction area (-) Pe two raw material permeability (JPU) ΔP: Suction pressure (m HxO) C,, Cs, tL: Raw material permeability from the coefficient or higher P,, Raw material temperature at the time of pallet charging T1. Dry apparent density j of sintered raw material, predicted value of porosity of packed bed at the time of pallet charging ε3. h: Filling bed height, suction pressure cup P
Given 1, the predicted firing rate V/ can be calculated from K by simultaneously equations (1) to αQ and α6.

Here, the raw material permeability P is calculated using the following formula (2) ~ α4'
1'4 Z, = ye4- z mouth X (1--)
−−−……−−−−−−α3Z4=Z,
−1−Z, °°°°°°°°°°°°°°
°°°°…°°°°°“@−α4A+ Be Cs k
,, k,, kR+ k4 + "S+ "a" coefficient d: Raw material dry particle size (volume median diameter) (ff) %) zo: Raw material dry water absorption rate (wt%) ffil: Added moisture rate (wt%) z,: Raw material initial moisture content (wt%) wi: l raw material dry amount (dry kl/hr) Wa, O:
Added water intake (moan/hr) In the above equation (2), the raw material dry water absorption x0 is as follows α・J
: 1 Dry amount of raw materials (4/hr for drying)”ai:
The raw material water absorption rate (wt%) 1+ and the raw material dry apparent density 1 are determined by the following Qη formula.

pI:l raw material apparent density - ring 7yd> Then, ε is determined by the following formula.

t, = C1・Sd+C,・d+C4・A+C5・h
CL+CI+・・・・・・・・・・・・(To) Sd: Raw material dry particle size dispersity d: Raw material dry particle size (volume median diameter) (cod) ACL
: Charge bulk (FFI) C1 to C6: Coefficient The raw material dry particle size dispersity sd and the raw material dry particle size d in the above formula (to) are determined by the following α formula and (to) formula, respectively.

d=Σ(fvt-dt) ・・・・・・
・・・・・・・・・・・・・・・・・・Kan h, yo ft
/P11003000.660. ．． 106100006
0. @ΣCf, /ρi) fi=w7/2Wi ・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・
: i raw material dry particle size Cm> SI, to: i raw material to weight ratio of dry particle size range (-) ρI: i raw material apparent density (Ton/m') fvt: irg
, diagonal volume ratio (-) f, :i raw material weight ratio (-) W7: i raw material dry amount (dry volume/hr) dk C
k Average particle size of dry particle size range (fi)l: Number of dry particle size ranges P = 1.0332・(1-ΔP/20)cs=o
, 2a.

Once the combustion speed is predicted in this manner, the moisture content of the sintering raw material, the charging bulk, the height of the packed beds, and the suction force of the main exhaust fan are selectively controlled in order to make the predicted value coincide with the target value. These control factors are operated within predetermined operating ranges, but the main exhaust fan suction force is operated when the charging bulk and packed bed height cannot be controlled without moving them out of the operating range.

Regarding the coefficient C3 of equation (1), the actual combustion distance V/
It is determined by associating M with U determined by Equation 06, or by associating the actual volume V/ with the actually measured wind speed U passing through the packed bed and calculating backwards. The actual combustion speed VfM can be determined using the following formula.

77M = Ps ・1vvp/h -----
−−−−−−−、、、、、－Working P3: Pallet speed (
m/min) lνFde: Firing distance Cm) Here, the firing distance is determined as the distance between the ignition furnace and the FFP by detecting the rising point as the FFP from the exhaust gas temperature pattern as shown in FIG.

Next, an embodiment of the present invention will be described based on FIG.

FIG. 1 shows the ninth example of a control system for implementing the method of this invention, in which (1) is a raw material tank, (2) is a mixer, (3) is a surge hopper, (4) is a drum feeder, and (5) is a surge hopper. ) is the ore feed shoe), (6) is the sintering machine barrel), (7) is the ignition furnace, and (8) is the main exhaust fan.

That is, the amount of nine raw materials cut out from each raw material tank (1) is inputted to the raw material dry apparent density, raw material dry particle size, raw material dry particle size dispersity, and raw material dry water absorption calculation device αQ, and the α9
The raw material dry apparent density, raw material dry particle size d, raw material dry particle size dispersity Sd, and raw material dry water absorption rate z0 are calculated using the formula, Kan formula, Kan formula, and α formula, respectively. Various sintering raw materials cut out from each raw material tank (1) are mixed together with moisture in a mixer (2). The amount of added water is detected by an added water amount detection/adjustment device (2) equipped with a flow meter (11-1) and a control valve (11-2). In the surge hopper (3), a thermometer (3-1) and a moisture meter (3-2) measure the raw material temperature T at the time of charging the pallet.
, and the raw material moisture content/rate z4 are measured. The material in the surge hopper (3) is fed with the feed amount adjusted by the rotation of the drum feeder (4), and is charged onto the sintering machine pallet (6) via the neat (5), and the pallet is moved. Along with this, a filled layer (9) is formed. The charging bulk HcL at the time of charging the raw material is adjusted by the charging bulk height controller (2) based on the measured value of the bulk meter (12-1). In addition, the bed height of the packed bed (9) is adjusted by adjusting the inclination angle and vertical position of the ore feeding chute (5) by the packed bed height detection/adjustment device (to), and the height of the nine layers is The height is input to the packed bed porosity calculation device@. And this packed layer (9
) is ignited from its surface in an ignition furnace (7). The suction pressure JP is determined by the damper (15-1) provided with the upstream pressure of the main exhaust fan (8) based on the measurement m of the suction pressure gauge (15-2).
is controlled by adjusting the damper opening degree and main exhaust fan rotation speed using the suction pressure regulator (to).

The raw material initial moisture content calculation device (1) calculates the amount w1 cut out from each raw material tank (1) and the added moisture amount detection/adjustment device α.
Added water amount WH, GM input from power and moisture meter (3-
Based on the raw material moisture content Z and K input from 2), the following (
Initial moisture content of the raw material using the formula 2. is calculated, and the result is input to the combustion rate control device (2) K.

WH, OM: ye, detected value of added moisture content of raw material to be measured (
The packed bed porosity calculation device α4 calculates the raw material dry apparent density, raw material dry particle size, raw material dry particle size dispersity, and raw material dry water absorption calculated by the raw material dry particle size d and raw material dry particle size calculated by the raw material dry water absorption calculation device QOK. Using the dispersion degree Sd and the charging bulk height ACL measured by the bulk meter (12-1), the packed bed porosity calculation device is calculated using the above formula (to), and the result is calculated by the packed bed passage wind speed calculation device. α
It is input to Q. 9. The packed bed passing wind speed U calculated by the packed bed passing wind speed calculating device α is inputted to the burning rate calculation device (to).

In the packed bed passage wind speed calculation device (to), there is a thermometer (3-1)
Raw material temperature T1 at the time of pallet charging inputted from, raw material moisture content 21 at the time of pallet charging inputted from moisture meter (3-2), raw material dry apparent density, raw material dry particle size, raw material dry particle size dispersity・Dry apparent density 1, dry particle size d1, dry water absorption rate z of the sintering raw material input from the raw material dry water absorption calculation device (to)
0, the predicted porosity value ε1 inputted from the packed bed porosity calculation device α◆, and the actual combustion speed V/M inputted from the packed bed height detection calculation device (toward) are input, and the above (2) to (total) are input. )
The packed bed passing wind speed U is calculated using the formula. The result is C
3 is input to the arithmetic unit @. The combustion rate calculation device (to) calculates the pallet speed PS input from the pallet speed detector α force, the filling bed height h input from the packed bed height detection/adjustment device (to), and the exhaust gas input from the exhaust gas temperature meter. The temperature is input, and the actual burning rate Vfw is calculated using the Kan formula.

The result is input to the C1 arithmetic unit @. C1 calculation device (to) receives the actual combustion speed V/M input from the packed bed passage wind speed U1 fuel burnup calculation device (to), which is input from the packed bed passage wind speed calculation device α. The coefficient C1t is calculated backwards using the above equation (1) by associating vfM with those for the same raw material. The combustion rate control device (to) calculates the raw material initial moisture content 2 inputted from the raw material initial moisture content calculation device.
8. Raw material dry apparent density f, raw material dry particle size d% raw material dry particle size dispersity Sd input from Q to the raw material dry apparent density, raw material dry particle size, raw material dry particle size dispersity, raw material dry water absorption calculation device , [Material drying water absorption rate z6, coefficient 01, etc. input from the C7 calculation device (c) are input, and the combustion rate of the raw material before charging to the pallet is predicted using equations (1) to (to), and the equipment In order to match the target value V8, the moisture content of the sintering raw material is detected by the added moisture amount detection device 0, the charging bulk is detected by the charging bulkiness controller (2), and the packed bed height detection/adjustment device (2) The height of each filling bed is selectively controlled, and the suction force of the main exhaust fan is selectively controlled by a suction pressure regulator (to).

Table 1 of Examples shows the average values of production rate, tumbler strength, reduction powdering rate, and puffiness when the method of this invention is implemented, and the porosity of the conventional packed bed is compared with the particle size dispersion of the sintered raw material. This figure shows a comparison with the case where the air permeability of the packed bed is controlled based on the calculated values.

Table 1 From Table 1, it was found that the method of this invention improved the production rate and tumbler strength compared to the conventional method, and also had a smaller reduction and powdering rate, as well as smaller variations in these factors. .

Effects of the Invention As described above, this invention calculates moisture content by material balance calculation etc.
In addition to calculating the porosity of the packed bed after assembly, the combustion rate, which is closely related to production rate and quality, is controlled by taking into account the permeability of the raw material, making it possible to perform feedforward control with higher precision. Therefore, according to the present invention, as is clear from the examples described above, it is highly effective in improving the productivity and stabilizing the quality of sintered ore in sintering operations.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a control system for carrying out the method of the present invention, and FIG. 2 is a diagram showing a method for determining the firing distance in the same method. 1... Raw material tank, 2... Mixer, 3... Surge hopper, 4... Drum feeder, 5... Ore feed chute, 6-... Sintering machine pallet, 7... Ignition furnace , 8...
Main exhaust fan, 9... Filled bed, 10... Raw material dry apparent density, raw material dry particle size, raw material dry particle size dispersity, raw material dry water absorption calculation device, 11... Added moisture amount detection/adjustment device ,1
2... Charging bulk height controller, 13... Packed bed height detection/adjustment device, 14... Packed bed porosity calculation device, 15...
Suction pressure regulator, 16... Packed bed passage wind speed calculation device,
17... Pallet speed detector, 18... Burning rate calculation device, 19... Burning rate control device, 20... Raw material initial moisture content calculation device, 21... C7 calculation device, 22.
・Exhaust gas thermometer. Applicant Sumitomo Metal Industries Co., Ltd. Agent 1) Ryo Carpenter, “,1-
Pano

Claims (1)

[Claims] Predict the combustion rate based on the air permeability, temperature, moisture, and dry apparent density of the sintering raw material determined in advance, as well as the porosity of the packed bed, the height of the packed bed, and the suction force of the main exhaust fan when loading the sintering machine pallet. A sintering operation method characterized in that the moisture content of the sintering raw material and/or the charging bulk and/or the height of the packed bed and/or the suction force of the main exhaust fan are adjusted in order to make this predicted value coincide with the target value.