EP3587975A1

EP3587975A1 - Sintering machine for sintered ore

Info

Publication number: EP3587975A1
Application number: EP18757056.9A
Authority: EP
Inventors: Takeshi Sekiguchi
Original assignee: JP Steel Plantech Co
Current assignee: JP Steel Plantech Co
Priority date: 2017-02-27
Filing date: 2018-02-19
Publication date: 2020-01-01
Also published as: JP6816250B2; EP3587975A4; TW201835518A; TWI661169B; WO2018155368A1; CN110249194A; JPWO2018155368A1

Abstract

Provided is a sintering machine, which makes it possible to effectively prevent gas leakage to secure high safety and also to increase the exhaust gas circulation amount.

A sintering machine (50) according to the present invention includes a sinter strand (6) having pallet cars that run on rails on a floor, and is used for producing sintered ore by, while the pallet cars are travelling, continuously burning sinter feed piled on the pallet cars, the machine (50) including: an exhaust duct (2) with a blower (14) for sucking exhaust gas from below the sinter strand (6) and discharging it to the outside; an exhaust gas circulating hood (1) over the pallet cars; an exhaust gas circulating duct (3) connecting between the exhaust duct (2) and the hood (1); and a seal portion hermetically sealing a gap between the hood (1) and the floor, and being configured to keep pressure of the inside of the hood (1) at or below the atmospheric pressure.

Description

Technical Field

The present invention relates to a sintering machine to be used for producing sintered ore by, while a plurality of pallet cars are travelling, continuously burning sinter feed piled on the plurality of pallet cars.

Background Art

A sintering machine is used for producing sintered ore by piling sinter feed on a plurality of pallet cars, in each of which the bottom of a carrying portion has a grating structure, and igniting the sinter feed bed by an igniter to continuously burn the sinter feed bed while the pallet cars are travelling.
A space is provided between rails laid on a floor, on which the pallet cars travel, and a number of wind boxes are arranged along the rails under the space. The oxygen required to burn the sinter feed bed on the pallet cars is supplied by the air sucked downward through the sinter feed bed from above the pallet cars by keeping the pressure in the wind boxes at a negative pressure.
Conventionally, in such a sintering machine, exhaust gas circulating operation is adopted for the purpose of, for example, reducing the amount of exhaust gas and the total amount of nitrogen oxide (NOx) that are discharged to the outside of the sintering machine as described in Japanese Patent Application Publication No. 2011-105985 (Patent Document 1).
Exhaust gas is sent to a circulation gas hood provided over the pallets via an exhaust gas circulating duct that branches from an exhaust duct, and a high-temperature circulating exhaust gas is supplied therefrom to the sinter feed bed on the pallets. This has an advantage that it is also possible to reuse the sensible heat of the exhaust gas in the sintering machine in addition to the above effect of reducing the amount of exhaust gas.

Prior Art Document

Patent Document

[Patent Document 1] Japanese Patent Application Publication No. 2011-105985 ( JP 2011-105985 A )

Summary of Invention

Problems to be Solved by the Invention

In order to prevent the exhaust gas of the sintering machine containing carbon monoxide (CO) etc. from leaking to the outside, complicated sealing is provided between the circulation gas hood, which is a fixed object, and the pallets, which are movable objects. However, the sealing portion is deformed by aging degradation and it is therefore difficult to keep sufficient sealing between such a fixed object and movable objects for a long time.
Furthermore, it is required to increase the amount of circulation of exhaust gas in order to reduce the amount of exhaust gas. However, increasing the amount of circulation of exhaust gas is hindered by the leakage of outside air into the wind boxes from under the pallets. This is because when the outside air is mixed into the exhaust gas by the leakage of the outside air into the wind boxes from under the pallets, the outside air that needs not to be subjected to the exhaust gas treatment in the first place is contained in the exhaust gas discharged from the exhaust duct, which reduces the substantial circulation amount of exhaust gas.
The present invention has been made to solve such problems and it is an object to provide a sintering machine, with which it is possible to effectively prevent gas leakage to secure high safety and it is also possible to increase the amount of circulation of exhaust gas.

Means for Solving the Problem

In order to solve the above problems, a sintering machine according to the present invention, which has a sinter strand having a plurality of pallet cars that run on rails laid on a floor, to be used for producing sintered ore by, while the plurality of pallet cars are travelling, continuously burning sinter feed piled on the plurality of pallet cars, is characterized by including:

an exhaust duct provided with a main blower for sucking exhaust gas from below the sinter strand and discharging the exhaust gas to the outside;
an exhaust gas circulating hood covering over the plurality of pallet cars;
an exhaust gas circulating duct connecting between the exhaust duct and the exhaust gas circulating hood; and
a floor seal portion hermetically sealing a gap between the exhaust gas circulating hood and the floor, wherein
the sintering machine is configured to keep pressure of an inside of the exhaust gas circulating hood at or below atmospheric pressure.

In the above sintering machine, the exhaust gas circulating hood may have a fixed hood and a movable hood, and be configured so as to be able to be at least partially opened and closed by moving the movable hood. In this case, the sintering machine may further include a hood gap seal portion for sealing a gap between the movable hood and the fixed hood in a state where the movable hood is closed.
The above sintering machine may be configured so that at least part of the exhaust gas in a portion provided with the exhaust gas circulating hood is returned to the exhaust gas circulating hood through the exhaust gas circulating duct.
The above sintering machine may further include a main dust collector provided to the exhaust duct, wherein
the main dust collector is provided upstream of the main blower in a flow direction of the exhaust gas, and
the exhaust gas circulating duct is connected to the exhaust duct between the main dust collector and the main blower.
In the above sintering machine, an inlet port for taking in outside air may be provided in the exhaust gas circulating duct. In this case, in the above sintering machine, the exhaust gas circulating duct may have a branch duct that branches from the exhaust gas circulating duct between the inlet port and a point of connection of the exhaust duct and the exhaust gas circulating duct, and
the branch duct may communicate with a space covered by the exhaust gas circulating hood at a position lower than a top of the pallet cars.
The above sintering machine may be such that a gas seal chamber is provided at at least one of end portions of the exhaust gas circulating hood in a longitudinal direction thereof, and the exhaust gas circulating duct is not connected to the gas seal chamber.
In the above sintering machine, a suction duct connected to a suction blower for sucking gas in the gas seal chamber may be connected to the gas seal chamber.
In the above sintering machine, the gas seal chamber may be formed by an outer block member and an inner block member, the outer block member blocking an opening between the exhaust gas circulating hood and both of the floor and the plurality of pallet cars, the inner block member being provided on an inner side of the outer block member with respect to the longitudinal direction of the exhaust gas circulating hood and blocking an opening between the exhaust gas circulating hood and both of the floor and the plurality of pallet cars.

Effects of the Invention

The sintering machine according to the present invention, which has a sinter strand having a plurality of pallet cars that run on rails laid on a floor, to be used for producing sintered ore by, while the plurality of pallet cars are travelling, continuously burning sinter feed piled on the plurality of pallet cars, includes: an exhaust duct provided with a main blower for sucking exhaust gas from below the sinter strand and discharging the exhaust gas to the outside; an exhaust gas circulating hood covering over the plurality of pallet cars; an exhaust gas circulating duct connecting between the exhaust duct and the exhaust gas circulating hood; and a floor seal portion hermetically sealing a gap between the exhaust gas circulating hood and the floor, wherein the sintering machine is configured to keep pressure of an inside of the exhaust gas circulating hood at or below atmospheric pressure. In this way, instead of providing sealing between the movable side (pallet cars) and the exhaust gas circulating hood (fixed side) as in conventional cases, the floor seal portion is provided between the floor and the exhaust gas circulating hood, both of which are on the fixed side. Thus, it is possible to sufficiently increase the sealing performance. Furthermore, since the sintering machine is configured to keep pressure of the inside of the exhaust gas circulating hood at or below the atmospheric pressure, it is possible to effectively prevent the exhaust gas from leaking to the outside.
Moreover, in conventional cases, the air leaked into the wind boxes from under the pallet cars is mixed into the exhaust gas and is discharged through the exhaust duct, which unnecessarily increases the volume of the exhaust gas. However, this leakage is replaced by the circulating exhaust gas that is circulated through the exhaust duct instead of the outside air, so that it is possible to increase the amount of circulation of exhaust gas proportionately with the amount of replaced gas.

Brief Description of Drawings

[FIG. 1] FIG. 1 is a schematic diagram of a sintering machine according to a first embodiment of the present invention.
[FIGS. 2A and 2B] FIGS. 2A and 2B are perspective views of an exhaust gas circulating hood of the sintering machine shown in FIG. 1, wherein FIG. 2A shows a state where movable hoods are closed and FIG. 2B shows a state where the movable hoods are opened.
[FIG. 3] FIG. 3 is a cross section of a pallet car, a wind box installed under the pallet car, and the exhaust gas circulating hood installed over the pallet car.
[FIG. 4] FIG. 4 is an enlarged view of part E in FIG. 3.
[FIGS. 5A and 5B] FIGS. 5A and 5B are schematic side views of the openable exhaust gas circulating hood included in the sintering machine according to the first embodiment of the present invention, wherein FIG. 5A shows a state where the movable hoods are closed and FIG. 5B shows a state where the movable hoods are opened.
[FIG. 6] FIG. 6 is a schematic side view showing a modification of the openable exhaust gas circulating hood.
[FIG. 7] FIG. 7 is a schematic diagram of an exhaust gas circulating hood included in a sintering machine according to a second embodiment of the present invention.

Embodiments for Carrying Out the Invention

Sintering machines 50 according to embodiments of the present invention will be described with reference to drawings.

As shown in FIGS. 1 to 4, a sintering machine 50 according to the present invention includes a sinter strand 6 having a plurality of pallet cars 6a that travel on rails 7 laid on a floor 5. The sintering machine 50 is used for producing sintered ore by, while the plurality of pallet cars 6a are travelling, continuously burning sinter feed that has been piled on the plurality of pallet cars 6a. The sintering machine 50 includes: an exhaust duct 2 provided with a main blower 14 for sucking exhaust gas from below the sinter strand 6 and discharging the exhaust gas to the outside; an exhaust gas circulating hood 1 covering over the plurality of pallet cars 6; an exhaust gas circulating duct 3 connecting between the exhaust duct 2 and the exhaust gas circulating hood 1; and seal members 4 hermetically sealing gaps between the exhaust gas circulating hood 1 and the floor 5, and the sintering machine 50 is configured to keep the pressure of the inside of the exhaust gas circulating hood 1 at or below the atmospheric pressure. When the pressure of the inside of the exhaust gas circulating hood 1 is kept at or below the atmospheric pressure, it is possible to effectively suppress the leakage of exhaust gas to the outside. However, in order to more effectively suppress the leakage of exhaust gas, it is preferable that the pressure of the inside of the exhaust gas circulating hood 1 be kept at a negative pressure.
The exhaust gas circulating hood 1 is provided downstream of an ore feeding device 17 and an igniter 18 in the travel direction of the sinter strand 6 and includes a plurality of fixed hoods 1a and a plurality of movable hoods 1b. The exhaust gas circulating hood 1 is configured so as to be able to be at least partially opened and closed by moving the movable hoods 1b. For this reason, the seal members 4 include floor seal plates 4a each for sealing the gap between the movable hood 1b and the floor 5 and hood gap seal plates 4b each for sealing the gap between the movable hood 1b and the fixed hood 1a. Each floor seal plate 4a is provided so that the whole of the floor seal plate 4a extends downward lower than a bottom end of the movable hood 1b. A bottom end surface of the floor seal plate 4a is in contact with the floor 5 in a slidable manner. On the other hand, the whole of an inside surface of the hood gap seal plate 4b is in contact with the fixed hood in a slidable manner.
The fixed hood 1a and the movable hood 1b are respectively provided with fixed hood ribs 35 and movable hood ribs 37 for ensuring strength thereof. Lower end portions of the fixed hoods are each provided with a fixed hood base member 36, which is hermetically and firmly fixed to the floor 5. At each end portion of the exhaust gas circulating hood 1 in the longitudinal direction thereof, the opening between the exhaust gas circulating hood 1 and both of the floor 5 and the plurality of pallet cars 6a is blocked by an end portion blocking member 25.
As shown in FIGS. 3 and 4, the floor seal plate 4a is provided along a lower edge portion of the movable hood 1b and fixed to the movable hood 1b. As shown in FIGS. 3 to 5, the hood gap seal plate 4b is provided at one end portion of the movable hood 1b in the longitudinal direction of the exhaust gas circulating hood 1 along part of the movable hood 1b that overlaps the fixed hood 1a in a state where the movable hood 1b is closed. The hood gap seal plate 4b is fixed to the movable hood 1b.
In the case of the first embodiment, the floor seal portion of the present invention includes the lower end portions of the fixed hoods 1a, that is, the portions providing the seal between the fixed hoods 1a and the floor 5, and includes the floor seal plates 4a provided on the movable hoods 1b. However, when the whole of the hood is constituted of the fixed hood only so as to be unopenable, the lower end portions of the fixed hood 1a function as the floor seal portion of the present invention.
Meanwhile, in the first embodiment, the hood gap seal plates 4b function as the hood gap seal portion.
As shown in FIG. 1, a plurality of wind boxes 22 are arranged under the sinter strand 6 along the longitudinal direction of the exhaust gas circulation hood 1. The exhaust duct 2 is connected to the wind boxes 22. The exhaust duct 2 is provided with a main dust collector 20. Part of the exhaust gas is sent to an exhaust gas treatment device (not shown) by the main blower 14 provided downstream of the main dust collector 20.
The exhaust gas circulating duct 3 is connected to the exhaust duct 2 between the main dust collector 20 and the main blower 14. The exhaust gas circulating duct 3 is provided with a circulating blower 15. Part of the exhaust gas flowing through the exhaust duct 2 is sucked by the circulating blower 15 and is returned to the exhaust gas circulating hood 1 through the exhaust gas circulating duct 3. When the circulating exhaust gas is sent from a point downstream of the main dust collector 20 into the exhaust gas circulating hood 1 in this way, an effect is brought about that conditions in the exhaust gas circulating hood 1 are kept clean, which reduces loads to the pallet cars 6a travelling in the hood to improve the lifetime thereof. Note that an electrostatic dust precipitator or a bag filter can be used as the main dust collector 20.
In the first embodiment, an inlet port 11 for taking in the outside air is provided in the exhaust gas circulating duct 3, so that it is possible to mix the outside air into the circulating exhaust gas with the use of an intake blower 16. Thus, it is possible to control the oxygen concentration in the gas to be used for combustion (mixture of air and the circulating exhaust gas) that is passed through the sinter feed bed for sintering. Furthermore, by reducing the temperature of the circulating exhaust gas to be sent into the exhaust gas circulating hood 1 to prevent the inside of the exhaust gas circulating hood 1 from becoming high temperature, it is also possible to reduce the damage to the internal constituent elements, such as pallet cars, that is caused by high temperature.
In a conventional configuration, all of the exhaust gas discharged from the wind boxes corresponding in position to the portion provided with the exhaust gas circulating hood is discharged to the outside and the exhaust gas discharged from the wind boxes corresponding in position to the portion not provided with the exhaust gas circulating hood is returned to the exhaust gas circulating hood through a duct. In contrast to this, in the first embodiment, the sintering machine is configured so that, while all of the exhaust gas from the portion provided with the exhaust gas circulating hood 1 is sucked through the exhaust duct 2, part of the sucked exhaust gas is returned to the exhaust gas circulating hood 1 through the exhaust gas circulating duct 3 connected to the exhaust duct 2. This makes it possible to install the exhaust gas circulating hood 1 substantially all over the sinter strand 6 in the longitudinal direction thereof. Furthermore, an effect is brought about that the outside air that leaked into the wind boxes through lower part of the pallet cars 6a in the case of conventional configurations is mostly replaced by the circulating exhaust gas. For this reason, as compared to the conventional case, it is possible to increase the amount of circulation of exhaust gas. Furthermore, in the first embodiment, the exhaust gas circulating duct 3 further includes a branch duct 3a that branches from the exhaust gas circulating duct 3 between the inlet port 11 and the point of connection of the exhaust duct 2 and the exhaust gas circulating duct 3. The branch duct 3a communicates, through the part of the floor close to car wheels 8, with the space covered by the exhaust gas circulating hood 1. The space covered by the exhaust gas circulating hood 1 is a space inside of the exhaust gas circulating hood 1, meaning the space defined mainly by the exhaust gas circulating hood 1, the floor, and the pallet cars 6a.
Since the branch duct 3a branches from the exhaust gas circulating duct 3 at a point upstream of the inlet port 11 in the flow direction of the circulating exhaust gas, the outside air is not mixed into the circulating exhaust gas flowing in the branch duct 3a.
The airtightness between the pallet cars 6a, which are mobile objects, and the wind boxes 22, which are fixed objects, is maintained by car-side slide members 6b and wind box-side rail members 22b, which act as sealing members that slide relative to each other in a contact state. When leakage occurs at this portion, the gas around the pallet cars 6a flows into the wind boxes 22 without passing through the sinter feed bed piled on the pallet cars 6a. When the circulating exhaust gas, into which no outside air is mixed, is returned to the space covered by the exhaust gas circulating hood 1 at a position lower than the top of the pallet cars 6a through the branch duct 3a as in the case of the first embodiment, it is possible to supply the circulating exhaust gas, into which the outside air is mixed and which therefore contains oxygen enough to burn the sinter feed, to the area above the pallet cars 6a, and also to increase the proportion of the circulating exhaust gas, into which no outside air is mixed, in the gas leaking through gaps under the pallet cars 6a.
As a result, it is possible to supply the circulating exhaust gas containing oxygen enough to burn the sinter feed to the area above the pallet cars 6a and to reduce the amount of exhaust gas discharged to the outside by maximizing the amount of circulation of exhaust gas.
Next, operation of the openable exhaust gas circulating hood 1 included in the sintering machine 50 according to the first embodiment will be described with reference to FIGS. 5A and 5B. Note that, in FIGS. 5A and 5B, the sinter strand 6 (pallet cars 6a) that travels in the hood is omitted for the sake of simplicity.
FIG. 5A shows a state where the movable hoods 1b are closed. In the first embodiment, two movable hoods 1b are provided at each of the openable portions and are brought into contact with each other to close the openable portion. In this state, the gap between the movable hood 1b and the floor 5 is sealed by the floor seal plate 4a, and the gap between the movable hood 1b and the fixed hood 1a is sealed by the hood gap seal plate 4b, so that the airtightness of the inside of the exhaust gas circulating hood 1 is maintained.
FIG. 5B shows a state where the movable hoods 1b are opened. As shown in this figure, the movable hoods 1b are configured to be movable along the fixed hoods 1a by movable hood wheels 10 provided at lower ends of the movable hoods 1b. When the two movable hoods 1b are moved in the opposite directions, a large opening length Lo is obtained. This makes it possible to easily and efficiently perform maintenance work, such as replacement of pallets. Such an openable exhaust gas circulating hood is realized owing to the configuration of the present invention, in which it is not required to seal the gap between the hood and the mobile objects, such as the pallet cars, along the entire length.

FIG. 6 shows a modification of the openable exhaust gas circulating hood 1 according to the first embodiment. In an exhaust gas circulating hood 1 of the modification, one movable hood 1b is provided at each of the openable portions and the movable hood 1b is configured so that the entire movable hood 1b can be lifted up with the use of suspending wires 100 or the like.
This modification has an advantage that while the movable hood 1b is somewhat harder to open as compared to the configuration of the first embodiment, the opening length Lo is approximately doubled.

Next, description will be given of part of an exhaust gas circulating hood 1 included in a sintering machine according to a second embodiment of the present invention with reference to FIG. 7, which part differs from the first embodiment.
In the second embodiment, a gas seal chamber 30 is provided at each of end portions of the exhaust gas circulating hood 1 in the longitudinal direction thereof. A suction duct 34 connected to a suction blower 33 for sucking the gas in the gas seal chamber 30 is connected to the gas seal chamber 30. The gas seal chamber 30 is formed by an outer block member 31 and an inner block member 32, the outer block member 31 blocking the opening between the exhaust gas circulating hood 1 and both of the floor 5 and the plurality of pallet cars 6a, the inner block member 32 being provided on the inner side of the outer block member 31 with respect to the longitudinal direction of the exhaust gas circulating hood 1 and blocking the opening between the exhaust gas circulating hood 1 and both of the floor 5 and the plurality of pallet cars 6a.
The arrows A to D in FIG. 7 are for explaining the flow rate balance between leakage and suction. At both end portions of the exhaust gas circulating hood 1 in the longitudinal direction thereof, it is very difficult to seal gaps. As shown in FIG. 7, however, the exhaust gas circulating ducts 3 are not connected to the gas seal chambers 30, that is, the circulating exhaust gas is not sent to the gas seal chambers 30, so that the seal against the circulating exhaust gas at both end portions of the exhaust gas circulating hood 1 in the longitudinal direction thereof becomes double sealing, and furthermore, leakage A on the outer block member 31-side and leakage B on the inner block member 32-side are prevented from becoming outward leakage by suction C on the suction duct 34-side, on which the gas seal chambers 30 are connected to an environmental dust collector 21, and suction D on the wind box 22-side in the gas seal chambers 30. For example, when the pressure of the area on the inner side of the inner block members 32 in the exhaust gas circulating hood 1 is the atmospheric pressure, the relation, the leakage A = the leakage B, is satisfied. When the pressure of the area on the inner side of the inner block members 32 in the exhaust gas circulating hood 1 is negative, the relation, the leakage A > the leakage B, is satisfied.
Since it is made possible to increase the negative pressure level in the gas seal chambers 30 to improve the effect of preventing the outward leakage, it is preferable that the suction duct 34 connected to the environmental dust collector 21 be connected to the gas seal chambers 30 to suck the gas in the gas seal chambers 30. However, also when such a suction duct 34 is not connected to the gas seal chambers 30, the effect of preventing the leakage is brought about by providing the gas seal chambers 30 and sucking the gas therein through the suction D.
While the present invention has been described with reference to the embodiments, the present invention is not limited to the above-described embodiments. The scope of the present invention is determined based on the attached claims and all the configurations obtained by omitting, changing, and/or improving the constituent elements within the scope of the present invention are also included in the present invention.
For example, in the above embodiments and the modification, the exhaust gas circulating duct 3 includes the branch duct 3a that branches from the exhaust gas circulating duct 3 between the inlet port 11 and the point of connection to the exhaust duct 2, and the exhaust gas circulating duct 3 communicates, through the part of the floor close to car wheels 8, with the space covered by the exhaust gas circulating hood 1. However, this is a preferable mode, which makes it possible to increase the proportion of the circulating exhaust gas, into which no outside air is mixed, in the gas leaking into the wind boxes through the gaps under the pallet cars 6a by returning the circulating exhaust gas, into which no outside air is mixed, to the vicinity of the sealing portions (the car-side slide members 6b and the wind box-side rail members 22b) between the pallet cars 6a and the wind boxes 22. Specifically, it suffices that the branch duct 3a communicate, at a position lower than the top of the pallet cars 6a, with the space covered by the exhaust gas circulating hood 1. For example, the branch duct 3a may be connected to a side portion of the exhaust gas circulating hood 1 at a position lower than the top of the pallet cars 6a. Alternatively, the branch duct 3a may be omitted.

Description of Reference Numerals

1: exhaust gas circulating hood
1a: fixed hood
1b: movable hood
2: exhaust duct
3: exhaust gas circulating duct
3a: branch duct
4: seal member
4a: floor seal plate
4b: hood gap seal plate
5: floor
6: sinter strand
6a: pallet car
6b: car-side slide member
7: rail
8: car wheel
9: sinter feed bed
10: movable hood wheel
11: inlet port
14: main blower
15: circulating blower
16: intake blower
17: feeder
18: igniter
20: dust collector
22: wind box
22b: wind box-side rail member
25: end portion blocking member
30: gas seal chamber
31: outer block member
32: inner block member
33: suction blower
34: suction duct
35: fixed hood rib
36: fixed hood base member
37: movable hood rib
50: sintering machine
100: suspending wire

Claims

A sintering machine, including a sinter strand having a plurality of pallet cars that run on rails laid on a floor, to be used for producing sintered ore by, while the plurality of pallet cars are travelling, continuously burning sinter feed piled on the plurality of pallet cars, the sintering machine being characterized by comprising:
an exhaust duct provided with a main blower for sucking exhaust gas from below the sinter strand and discharging the exhaust gas to the outside;

an exhaust gas circulating hood covering over the plurality of pallet cars;

an exhaust gas circulating duct connecting between the exhaust duct and the exhaust gas circulating hood; and

a floor seal portion hermetically sealing a gap between the exhaust gas circulating hood and the floor, wherein

the sintering machine is configured to keep pressure of an inside of the exhaust gas circulating hood at or below atmospheric pressure.
The sintering machine according to claim 1, characterized in that
the exhaust gas circulating hood includes a fixed hood and a movable hood, and is configured so as to be able to be at least partially opened and closed by moving the movable hood.
The sintering machine according to claim 2, characterized by further comprising a hood gap seal portion for sealing a gap between the movable hood and the fixed hood in a state where the movable hood is closed.
The sintering machine according to any one of claims 1 to 3, characterized by being configured so that at least part of the exhaust gas in a portion provided with the exhaust gas circulating hood is returned to the exhaust gas circulating hood through the exhaust gas circulating duct.
The sintering machine according to any one of claims 1 to 4, characterized by further comprising a main dust collector provided to the exhaust duct, wherein
the main dust collector is provided upstream of the main blower in a flow direction of the exhaust gas, and
the exhaust gas circulating duct is connected to the exhaust duct between the main dust collector and the main blower.
The sintering machine according to any one of claims 1 to 5, characterized in that
an inlet port for taking in outside air is provided in the exhaust gas circulating duct.
The sintering machine according to claim 6, characterized in that
the exhaust gas circulating duct includes a branch duct that branches from the exhaust gas circulating duct between the inlet port and a point of connection of the exhaust duct and the exhaust gas circulating duct, and
the branch duct communicates with a space covered by the exhaust gas circulating hood at a position lower than a top of the pallet cars.
The sintering machine according to any one of claims 1 to 7, characterized in that
a gas seal chamber is provided at at least one of end portions of the exhaust gas circulating hood in a longitudinal direction thereof, and
the exhaust gas circulating duct is not connected to the gas seal chamber.
The sintering machine according to claim 8, characterized in that
a suction duct connected to a suction blower for sucking gas in the gas seal chamber is connected to the gas seal chamber.
The sintering machine according to claim 8 or 9, characterized in that
the gas seal chamber is formed by an outer block member and an inner block member, the outer block member blocking an opening between the exhaust gas circulating hood and both of the floor and the plurality of pallet cars, the inner block member being provided on an inner side of the outer block member with respect to the longitudinal direction of the exhaust gas circulating hood and blocking an opening between the exhaust gas circulating hood and both of the floor and the plurality of pallet cars.