JPH08166190A - Quick lime recovery device fired on sinter machine pallet - Google Patents

Abstract

(57) [Abstract] [Purpose] Recovery of a recovery device that produces quicklime powder from limestone powder at the uppermost layer of the raw material on the pallet of the Dwightroid-type sintering machine, and aspirates and recovers the produced quicklime powder with a recovery hood. Increase efficiency. [Structure] The width of the recovery hood 25 including the seal skirt 26 is set to be equal to or slightly smaller than the width W of the quicklime powder 22 (that is, the width W of the recess) so that the inner width of the recess can be fitted. Therefore, the gap between the seal skirts does not expand, the phenomenon of decrease in air flow velocity disappears, suction force is secured, and recovery efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to quick lime powder calcined in the uppermost layer of a sintering raw material layer packed on a pallet of a Dwightroid-type sintering machine, which is sucked from the surface layer of a sintered ore simultaneously sintered,
It relates to a device for collecting.

[0002]

2. Description of the Related Art A schematic diagram of a sintering operation of a raw material for a blast furnace using a Dwightroid type sintering machine is shown in FIG. Bedding ore hopper 3
The sintering raw material 2 cut out from the ore feeding hopper 4 is stacked and supplied on the bedding ore cut out on the pallet 1.
The sintering raw material 2 is ignited by the ignition device 15, and the coke powder in the sintering raw material 2 is burned by the ventilation of the main blower 14, and the sintering raw material is fired to become a sintered ore. The sinter is
After being crushed by the crusher 5 and cooled by the cooler 6, it is classified by the sieving machine 7. Then, the product having a particle size of 8 to 16 mm on the sieve is returned to the bedding ore hopper 3 as the bedding ore 10, and the remainder is transported to the blast furnace as the product 13. On the other hand, the classified particles having a particle diameter of 5 mm or less are mixed with the new raw material 12 by the mixer 8 as the return ore 11, and then returned to the feed hopper 4.

In the sintering operation, as a means for improving the air permeability of the on-pallet raw material 2, a binder is generally mixed in the raw material, and quick lime (CaO) is often used as the binder. . As a method for producing the CaO at low cost, JP-A-3-183730 discloses that limestone (CaCO ₃ ) powder 9 mixed with powder coke is cut out from a lime hopper 19 and, as shown in FIG. Has proposed a method of loading the limestone powder 9 into a recess formed in the central portion in the width direction. By this method, the calcination temperature distribution of limestone in the pallet width direction is made uniform, and highly efficient and high quality quicklime is produced. It is possible to

On the other hand, as an apparatus for efficiently recovering quicklime produced on a sintering machine from the sintering machine, the inventors of the present invention disclosed in Japanese Unexamined Patent Publication No. 6-66477 a plurality of suction nozzles and air blow nozzles. We proposed a device consisting of a hood surrounding these. This device, as shown in FIG.
A recovery hood 25 is provided to cover the upper surface of the quicklime powder 22 generated in the recesses on the sinter ore 23 traveling in the pallet traveling direction 31, and air is blown into the recovery hood 25 from an air blow nozzle 29 to blow up the quicklime powder 22. Then, it is sucked and collected by the suction nozzle 24. A seal skirt 26 is provided at the lower end of the side surface of the recovery hood 25, so that the sintered ore 2
A seal is provided between the upper surface of the collecting hood 3 and the upper surface of the collecting hood 3, and a rear hood rear surface seal 30 is provided at the lower end of the rear surface to perform similar sealing.

[0005]

When a recovery hood having the same width as the width of the quicklime powder layer is applied to the quicklime powder buried in the recess, as shown in FIG.
The seal skirt 26 on the side surface of the concave portion bends, and as shown in FIG.
Due to the flow of air sucked from 8, a part of the quicklime powder near the upper end of the recess side wall is entrained in the direction of the suction nozzle 24,
The gap 28 expands as shown in FIG. As a result, the flow velocity of the air passing through the gap 28 decreases, and the suction air 27 flowing through the suction nozzle 24 falls below the flow velocity (about 25 m / sec) required to accompany quicklime, and as shown in FIG. There was a problem that the quicklime powder 22 located under the side wall of the recess was left behind. That is, there is a problem in that the uncollected quicklime powder 22 remains at the lower part of the side wall of the recess, and the recovery rate is reduced. Further, in order to collect the residual quicklime powder 22, the number of suction nozzles 24 is increased,
It is possible to increase the suction power, but this will increase the burden of equipment costs and operating costs.

An object of the present invention is to provide a device for highly efficiently recovering quicklime powder 22 burned in the concave portion of the pallet uppermost layer.

[0007]

The present invention was developed in order to solve the above-mentioned problems, and it is the uppermost layer of the raw material on the pallet of the Dwightroid-type sintering machine, and the pallet is formed in the central portion in the pallet width direction. A mixture of limestone powder and coke powder is charged into the formed recess to produce quicklime powder from limestone powder by heat in the ignition furnace and combustion heat of coke powder, and the produced quicklime powder is sucked by a recovery hood from the pallet, In the recovery device for recovering, the width of the recovery hood is set to a size that can fit into the inner width of the recess, and the recovery device for quicklime powder fired on the sinter machine pallet.

In this case, it is more preferable to provide side air blow nozzles in the vicinity of both side walls of the recess on the upstream side and / or the downstream side of the pallet of the recovery hood, and further, the side provided near the both side walls of the recess side on the downstream side. In addition to the partial air blow nozzles, it is more effective to arrange the central air nozzles in a row.

[0009]

The structure and operation of the present invention will be described below with reference to FIGS. 1 is a sectional front view of the recovery hood 25, and FIGS. 2 and 3 are a side view and a plan view, respectively. The collecting hood 25 sucks and collects the quicklime powder 22 generated in the upper concave portion of the central portion of the sinter 23 layer, and includes an air blow nozzle 29, a suction nozzle 24, and a skirt 26. In the present invention, the width of the recovery hood 25 including the seal skirt 26 is set to be equal to or slightly narrower than the width W of the quicklime powder 22 (that is, the width W of the recess) so that the inner width of the recess can be fitted. Therefore, the recovery hood fits into the recess, and the seal skirt 26 is located on the bottom surface of the recess.
Contact the surface. Therefore, the gap of the seal skirt portion does not expand, and the phenomenon of the decrease in the air flow velocity that occurs in the lower portion on the wall side of the recess is eliminated. That is, the suction force is secured and the quick lime recovery efficiency is improved.

Further, a blow air tube 33 is provided on the upstream side and / or the downstream side of the recovery hood 25, and air blow nozzles 32 for injecting the blow air tubes 33 are provided at both ends in the vicinity of the recess side wall. A partial air blow nozzle is also provided. It is preferable that these air blow nozzles 32 are configured to inject the ejection ports inward in the width direction to eject the air at the most optimal positions. The quicklime powder on the side wall of the recess is forcibly moved to the center of the recovery hood 25, and the suction nozzle 24
The rate of recovery of quick lime is improved by being sucked and recovered by.

[0011]

EXAMPLE First, quicklime powder was collected in the case where the side air blow nozzle 32 was provided only on the upstream side of the hood in the configuration of the present invention shown in FIG. As shown in Table 1, the operating conditions (operating conditions) were as follows: the lime layer thickness was 50 mm, the lime layer width was 700 mm, the width of the recovery hood body was 600 mm, and the total width including the skirt was 700 mm. In addition, the side air blow nozzle 32 has a diameter of 25 mm.
Individual pieces were provided, and the air velocity in the nozzle was 70 (m / sec).
As a result, as shown in Table 1, the recovery rate of quicklime powder was
In the past, it was about 86%, but was greatly improved to 97%.

[0012]

[Table 1]

Further, it was carried out in the case where the number of the side air blow nozzles 32 was four in addition to the upstream side of the recovery hood as well as the downstream side. As a result, the quick lime recovery rate was 99.
It greatly improved with%. These 4 side blow nozzles 3
The arrangement of No. 2 also solved the problem that quick lime was left behind not only in the side wall of the recess but also in the center.

[0014]

According to the present invention, the width of the recovery hood is set so as to fit the inner width of the recess so that the skirt of the recovery hood fits in the recess, and further, the upstream side and / or the downstream side of the recovery hood. By providing air blow nozzles at both ends of the concave portion on the side, the recovery rate of quicklime powder is further improved.

[Brief description of drawings]

FIG. 1 is a front view of an apparatus showing the application of the present invention.

FIG. 2 is a side view of an apparatus showing the application of the present invention.

FIG. 3 is a plan view of an apparatus showing the application of the present invention.

FIG. 4 is an explanatory diagram of a quick lime manufacturing process on a sintering machine.

FIG. 5 is a schematic view of a raw material loading concave portion in the pallet width direction.

6 (a) is a side view and FIG. 6 (b) is a front view showing an application example of a conventional recovery device.

FIG. 7 is an enlarged view of a side view of a concave portion immediately before starting suction.

FIG. 8 is an enlarged view of a side view of a concave portion immediately before starting suction.

FIG. 9 is a cross-sectional view in the pallet width direction showing a residual portion after suction collection by a conventional method.

[Explanation of symbols]

1 Pallet 2 Sintering Raw Material 3 Bed Ore Hopper 4 Feeding Hopper 5 Crusher 6 Cooler 7 Sieve Screener 8 Mixer 9 Limestone Powder 10 Bed Ore 11 Return Ore 12 New Raw Material 13 Product 14 Blower 15 Igniter 19 Limestone Hopper 22 Quick Lime Powder 23 Sintered Ore 24 Suction Nozzle 25 Recovery Hood 26 Seal Skirt 27 Flow Direction of Suction Air 28 Gap 29 Air Blow Nozzle 30 Recovery Hood Rear Seal 31 Pallet Travel Direction 32 Side Air Blow Nozzle 33 Blow Air Pipe 34 Central Air Blow Nozzle

Claims (3)

[Claims] 1. A mixture of limestone powder and coke coke is charged into the recess formed in the center of the pallet width direction at the uppermost layer of the raw material on the pallet of the Dwightroid sinter, and heat and powder in the ignition furnace are charged. In a recovery device that manufactures quicklime powder from limestone powder by the heat of combustion of coke and sucks and recovers the produced quicklime powder from a pallet by a recovery hood, the width of the recovery hood is a dimension that can fit into the inner width of the recess. A quick lime powder recovery device fired on a sinter machine pallet. 2. Recovery of quicklime burned on a sinter pallet according to claim 1, wherein side air blow nozzles are provided in the vicinity of both side walls of the recess on the upstream side and / or the downstream side of the pallet of the recovery hood. apparatus. 3. The quick lime calcined on a sinter machine pallet according to claim 2, wherein a central air nozzle is provided in addition to side air blow nozzles provided in the vicinity of both side walls of the recess on the downstream side. Recovery device.