JPS62199735A - Method for supplying sintered ore to sintering and cooling machine - Google Patents

Abstract

PURPOSE:To improve the efficiency of recovering waste heat and cooling capacity by subjecting sintered ore to primary crushing and sieving, subjecting the coarse grains to secondary crushing, adequately supplying the small and middle grains as they are to a cooling machine and allowing the fine grains to bypass the cooling machine. CONSTITUTION:The sintered one 2 of a high temp. obtd. by a sintering machine 1 is subjected to the primary crushing to about <=100mm by a crushing machine 4 provided with a guide 3 and a driven gear 5. The sintered ore subjected to the primary crushing is sieved to by a stationary grizzly 16 to the coarse grains sized about 100-500mm, the middle grains sized about 50-30mm, the small grains sized about 30-10mm, and the fine grains sized about -10mm at a sintered one feeding device 15. The coarse grains are subjected to the secondary crushing by a crushing machine 17 and are then uniformly supplied transversely to the cooling machine 7. The small and middle grains are segmented in the transverse direction of the cooling machine 7 and are supplied thereto. The sensible heat of the coarse, middle and small grains are recovered in a waste heat recovering part provided with hoods 8, 8a, a duct 9, a heat exchanger 10 and a circulation fan 11 in the cooling machine; thereafter, the grains are fed into a secondary sieving station 14 through the cooling part provided with a fan 12 and a chimney 13. On the other hand, the fine grains are bypassed along the cooling machine 7 via divided shoes 18 and a conveyor 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for supplying sinter to an iron ore sinter cooler, and relates to a method for efficiently cooling sinter and recovering exhaust heat.

[Conventional technology]

In recent years, sinter coolers have been used to recover the sensible heat of sintered ore discharged from a sintering machine, and Japanese Patent Application Laid-Open No. 56-29635.56-166338 has been proposed as a technique for this. However, the sintered ore is only primarily crushed in the ore discharge section of the sintering machine, and coarse particles and fine particles are mixed therein, which causes the following problem.

FIG. 6, which is an explanatory diagram of a conventional iron ore sinter cooling process, will be described below.

The high-temperature sintered ore 2 that has been sintered by the sintering machine 1 falls onto the crushing guide 3 , is further crushed by the crusher 4 and the receiving teeth 5 , and passes through the chute 6 to the cooler 7 . Supplied on top.

As a recent technical trend, as shown in FIG. 6, an exhaust heat recovery device consisting of a hood 8.8a, a duct 9, a heat exchanger 10, and a circulation fan 11 is installed in the front half of the cooler 7. In many cases, the sensible heat of sintered ore 2 is recovered. The sintered ore that has passed through the waste heat recovery zone 30 is sent to the fan 12 and the exhaust pipe 1.
The powder enters the cooling zone 31 consisting of three parts, is cooled to around 80'O, and is supplied to the next step, the secondary crushing and sieving station 14, where the particle size is adjusted.

In the exhaust heat recovery zone 30 and the cooling zone 31, the particle size of the sintered ore has a large influence on the efficient heat exchange and removal of the sensible heat possessed by the sintered ore. ~30mm medium grains, 30-10mm small grains,
and -10mm fine grained sintered ore are all mixed together,
Since the coarse sintered ore is supplied to the cooler 7, the coarse sintered ore of 100 to 50 mm is discharged from the cooler 7 without sufficient heat being removed to the inside, and when it is crushed at the secondary crushing and sieving station 14, it recuperates. , which had a negative impact on the transportation equipment for the next process.

Furthermore, if fine particles of 10 mm are mixed in the packed beds of the cooling zone 31 and the waste heat recovery zone 30, air permeability will deteriorate, pressure loss will increase, and fan power will increase. Furthermore, the gas flow may be biased, and efficient heat exchange may not take place.

[Problem that the invention seeks to solve]

The present invention uses coarse grains of 100 to 50 mm as described above,
30mm medium grain, 30-10mmc7) small grain, and -
There are various adverse effects caused by the fact that all 10 mm fine grain sintered ore is supplied to the cooler in a mixed state, namely, a decrease in the exhaust heat recovery efficiency of the cooler, a decrease in cooling capacity in the cooling zone, and a decrease in fan power due to increased ventilation resistance. The purpose of this is to solve the problems of an increase in sintered ore and a reduction in the life of conveying equipment due to heat recovery during secondary crushing of coarse-grained sintered ore.

[Means for solving problems]

The present invention has been developed in order to solve the above-mentioned problems, and provides a primary technical means for supplying the sintered ore that has been primarily crushed in the sintering machine discharge section to the sintering cooler. Lectured.

■The sintered ore is made into coarse grains of 100-50mm, 50-30mm.
Sieve into medium grains of m, small grains of 30 to 10 mm, and fine grains of -10 mm.

■Coarse particles are crushed secondarily and supplied uniformly to the cooling machine in the width direction of the trough.

■Medium grains and small grains are divided and fed in the width direction of the cooler trough.

(2) Fine particles bypass the cooler.

■Install a partition damper inside the hood.

[Effect]

Generally, the amount of heat transfer q, pressure loss, and loss ΔP of a packed bed are expressed by the following formula.

・・・・・・(1) ・・・・・・(2) where q: heat transfer amount (KcaJ1/ln'h) K1: coefficient related to particle shape Dp=average particle diameter (m) e: porosity (- ) h p': Heat transfer coefficient between particles and fluid (kCa/I
T+'・h・℃) tF: Fluid temperature (℃) Ls: Solid temperature (℃) ΔP: Pressure drop (kg/rn') K2: Coefficient related to particle shape ρ: Fluid density (kg/m'') V: Average granulation (m/5ec) As shown above, the amount of heat transfer q and pressure loss ΔP of the packed bed
is largely influenced by the average particle diameter Dp of the sintered ore; decreasing Dp increases the specific surface area of the particles and increases the contact area with the air flow, which is a heating medium, improving the amount of heat transfer, but conversely, the pressure The losses will be large.

Focusing on this principle, in order to efficiently remove the sensible heat of the sintered ore in the cooler, a fixed grizzly and a crusher are installed between the sintering machine discharge section and the cooler. By sequentially increasing the sieve size in multiple stages from the upstream side to the downstream side, the sintered ore can be made into coarse grains (100 m
m ~ 50 mm), medium grain (50 ~ 30 mm), small grain (30
sieved into fine particles (-10 mm);
Coarse particles are crushed into medium size or smaller by a crusher, and then fed uniformly in the width direction of the sintering machine, and medium and small sintered ore are divided and fed in the width direction of the cooling machine. A damper is installed on the L side of the separated sintered ore to adjust the air flow, and the fine sintered ore is directly bypassed to the sieving station in the next process without passing through the cooler, so that it can be discharged by the cooler. The aim is to improve heat recovery efficiency and cooling capacity.

〔Example〕

FIG. 1 shows an embodiment in which a sintered ore feeding device 5 used for carrying out the present invention is disposed between a sinter 4111 and a cooler 7, and FIGS. An AA arrow view and a BB arrow view in the figure are shown.

To explain in detail using these figures, as shown in FIG.
A sintered ore feeding device 15 is disposed between the primary crushing process consisting of the receiving teeth 5 and the exhaust heat recovery and cooling process by the cooling 4117.

This sintered ore feeding device 15 has a diameter of about 40 mm in the direction of transport of the sintered ore 2.
The sieve size of the fixed grizzly 16 with a downward slope of more than
For example, 10 mm, 30 mm toward the downstream side from DI)
, 50 mm, and a crusher 17 is provided for crushing coarse sintered ore exceeding the sieve size of 5.0 mm of the grizzly 16 to 50 mm or less. There is.

Furthermore, the 10 mm fine sintered ore 19 sieved by the grizzly 16 is transferred to the stage sieve 14 for the next process by a conveyor 20 disposed at the lower part of the cooler 7 through a dividing chute 18. It has become.

In addition, 30 to 10 m sieved by the Grizzly 16
The small sintered ore 21 having a diameter of 50 mm and the medium sintered ore 22 having a diameter of 50 to 30 mm can be divided and charged in the width direction of the trough of the cooler 7 by dividing chutes 23 and 24. In addition, the hood 8 of the exhaust heat recovery zone 30 and the cooling zone 31
A damper 27 is provided on the boundary line between the medium-grained sintered ore 22 and the small-grained sintered ore 21, as shown in FIGS. 1 and 4. Therefore, medium-grained sintered ore requires a longer cooling time than small-grained sintered ore at the same air volume. By adjusting the degree and controlling the amount of passing air in the width direction, it is possible to equalize the heat removal effect due to the difference in particle size between medium particles and small particles.

Note that the mounting direction of the grizzly 16 is such that the sinter is transferred in the opposite direction to the transfer direction of the cooler 7 in the embodiment shown in FIG. It may also be installed to transport condensate.

A procedure for supplying high-temperature sintered ore 2 to cooler 7 using sintered ore feeding device 15 will be explained. First, the high-temperature sintered ore 2 that has been fired by the sintering machine 1 falls onto the guide 3 in the ore discharge section, and is first crushed into pieces of 100 mm or less by the crusher 4 and receiving teeth 5, and is then placed directly below. The raw materials are put into a grizzly 16 and sieved from the upstream side in the order of, for example, mesh openings of 10 mm, 30 mm, and 50 mm.

110 that was sieved on the first stage of Grizzly 16 and became the bottom of the sieve
The fine-grained sintered ore 19 with a diameter of 1.5 mm is taken out of the thread by the chute 18, bypassed by the cooling @ 7, and sent to the sieving station 1 in the next step by a conveyor 20 installed at the bottom of the cooler 7.
4 will be sent directly.

In addition, 30-10 mm small sintered ore 21 and 50 were sieved in the second and third stages of Grizzly 16 and became the bottom of the sieve.
Medium-grained sintered ore 22 of ~30 mm is charged into the trough 25 of the cooler 7 in sections in the width direction by a chute 23,24.

Furthermore, the coarse sintered ore of 50 mm or more that has been sieved in the third stage of the Grizzly 16 is crushed by a crusher 17 for 50 m
The crushed sintered ore 26 is crushed into smaller pieces than the small-sized sintered ore 21 and the crushed sintered ore 26 is charged uniformly in the width direction of the trough 25 of the cooler 7 before the small-sized sintered ore 21 and the medium-sized sintered ore 22. With such an ore feeding method, as shown in FIG. 2, the secondary crushed sintered ore 26 is loaded uniformly in the width direction on the trough 25 in the lower stage.
In the upper layer, a charging layer is formed in which small-grained ore 21 is stratified on the right side of the figure, and medium-grained ore is stratified on the left side of the figure. The sintered ore, which has been charged into the trough after removing the fine grains and stratified according to grain size, has appropriate heat transfer and pressure drop, as seen in the theoretical formulas for heat transfer ff1q and pressure loss ΔP. This relationship was maintained for efficient cooling and improved exhaust heat recovery efficiency.

FIG. 4 is a cross-sectional view of the pallet section when the charging layer shown in FIG. 2 is located in the exhaust heat recovery zone, and is a sectional view of the small ore 21 divided in the width direction. A damper 27 is placed on the dividing point of the medium-grained ore 22.
By adjusting the inclination of this damper 27, the amount of cooling air indicated by the arrow in the figure is controlled, thereby achieving uniform cooling in the width direction.

Figure 5 shows the particle size distribution of sintered ore after primary crushing, and from this the proportion of -10mm fine grained ore sintered ore is approximately 35%, 30%.
~10 small grain sintered ore is about 15%, 50-30mm medium grained sintered ore is about 20%, +50mm coarse grained sintered ore is about 30%
That's about it.

〔Effect of the invention〕

(1) Coarse grain sintered ore of 100 to 50 mm is refined to 50 mm or less, and medium grained sintered ore of 50 to 30 mm and 30
~10mm medium-grained sintered ore is pre-classified, separated and charged in the width direction of the trough of the cooler, and the air volume is adjusted with a rough damper to improve the efficiency of exhaust heat recovery in the exhaust heat recovery zone of the cooler. and increase steam and power recovery. In addition, since the cooling zone can be cooled with a small breeze, the power required for the cooling fan can be reduced.

(2) By pre-classifying -10 mm fine sintered ore and discharging it outside the system, the ventilation resistance of the packed bed in the cooler is reduced, and the electric power of the circulation fan and cooling fan can be reduced.

(3) There are no problems such as heat recovery during the secondary crushing of coarse sintered ore, and the life of conveyance equipment for subsequent processes is extended, leading to a reduction in maintenance costs.

[Brief explanation of drawings]

Fig. 1 is an overall system diagram showing the method of supplying sintered ore to a cooler of the present invention, Fig. 2 is a view taken along arrow A-A in Fig. 1, and Fig. 3 is a view taken along arrow B-B in Fig. 1. 4 is a cross-sectional view of a pallet portion in an exhaust heat recovery zone, FIG. 5 is a particle size distribution diagram of primary crushed sintered ore, and FIG. 6 is an explanatory diagram of the prior art. 1... Sintering machine 2... Sintered ore 7... Cooler 14... Secondary station 15... Sintered ore feeding device 16... Grizzly 17... Secondary crushing Machine 18...Divided chute 19...Fine sintered ore 20...Transport conveyor 21...Small sintered ore 22...Medium sintered ore 23...Medium sintered ore charged Chute 24...Small sintered ore charging chute 25...Trough 26...Secondary crushed sintered ore 27...Dumper

Claims (1)

[Claims] 1. When supplying the sintered ore that has been primarily crushed in the sintering machine discharge section to the sinter cooler, the sintered ore is sieved into coarse grains, medium and small grains, and fine grains, and the coarse grains are crushed secondarily. sintered ore supply to a sinter cooler, characterized in that the sintered ore is supplied uniformly in the width direction of the cooler, the small and medium grains are divided and supplied in the width direction of the cooler, and the fine grains are fed by bypassing the cooler. Method.