JP7832012B2 - Intake and exhaust system for sintered ore cooler - Google Patents

Description

This invention relates to a supply and exhaust system for a sintered ore cooling machine, which stacks sintered ore, sintered in a sintering machine, onto multiple trough troughs, and continuously cools the sintered ore by passing a cooling gas through the layers of sintered ore while moving the multiple trough troughs.

Conventionally, a sintered ore cooling system is known that stacks sintered ore produced by a sintering machine onto multiple trough troughs, and continuously cools the sintered ore by passing a cooling gas from bottom to top through the layers of sintered ore while moving these trough troughs.

In such sintered ore coolers, due to recent increases in environmental regulations, at least a portion of the upper part of the trough carriage is covered with a hood to suppress leakage of sintered ore dust outside the system, and a sealing mechanism is provided between the hood and the trough carriage to maintain airtightness.

Japanese Patent Application Publication No. 59-13892

The trough bogie is a movable body that travels on rails, while the hood is a fixed body that is permanently installed on the moving trough bogie. Therefore, the sealing mechanism needs to be designed to allow for relative movement between these two components. One such sealing mechanism involves attaching a long piece of sealing material, such as a cross-section, to the fixed hood so that one side of the sealing material hangs downwards, and then sealing the gap between the hood and the trough bogie by making surface contact with the side of the trough bogie. Another method, as disclosed in Patent Document 1, uses a water-seal type seal that utilizes water stored in a water-seal box.

However, when using cloth sealant, gas and dust could leak due to wear and tear of the cloth over time, or due to gaps developing in the height and width directions between the hood and the trough bogie. In particular, if the side walls of the trough bogie deform, the trough bogie sinks due to wheel wear, or the trough bogie becomes eccentric in the axle direction, the gap between the trough bogie and the hood widens, increasing the amount of leakage. While there are methods to mechanically press such sealing material (cloth, etc.) against the sealing surface (trough bogie), if the sealing surface deforms into a wavy shape, gaps will develop, making gas and dust more likely to leak.

Furthermore, in the case of water-sealed seals, if leaked sintered ore accumulated inside the water-seal box, it could create resistance during cooler rotation or even cause the water-seal function itself to be lost.

This invention was made to solve the aforementioned problems, and aims to provide a supply and exhaust system for a sintered ore cooler that can prevent gas and dust from leaking out of the system from the sealing portion between the trough bogie side (movable side) and the hood side (fixed side), even when the sealing effect of the sealing mechanism decreases due to aging or other deterioration, resulting in a gap between the trough bogie and the hood.

(1) The sintered ore cooling machine supply and exhaust device according to the present invention is a sintered ore cooling machine supply and exhaust device that stacks sintered ore sintered by a sintering machine on a plurality of trough troughs, at least a part of which is covered from above by a hood, and continuously cools the sintered ore by passing a cooling gas through the layers of sintered ore while moving the plurality of trough troughs,
A cooling gas pumping device for supplying the cooling gas to the lower part of the plurality of trough trolleys,
An exhaust gas suction device for drawing exhaust gas from the space covered by the aforementioned hood and discharging it to the outside,
A control device configured to control at least one of the cooling gas pumping device and the exhaust gas suction device such that the flow rate of the cooling gas is less than the flow rate of the exhaust gas,
It is characterized by having the following features.

(2) In addition, in the case described in (1) above, the cooling gas pumping device has a pumping pipe equipped with a cooling gas flow meter for measuring the flow rate of the cooling gas,
The exhaust gas suction device has an exhaust pipe equipped with an exhaust gas flow meter for measuring the flow rate of the exhaust gas,
A flow control valve is provided in at least one of the pressure pipe and the exhaust pipe.
Preferably, the control device is configured to control the flow rate adjustment valve based on the measured values of the cooling gas flow meter and the exhaust gas flow meter.

(3) Furthermore, in the device described in (2) above, it is preferable that the control device is configured to control the cooling gas flow rate control valve and the exhaust gas flow rate control valve based on the amount of air leakage, such that the relationship (flow rate of exhaust gas) ≥ (flow rate of cooling gas) - (amount of air leakage) is satisfied.

(4) In addition, in any of the above (1) to (3), each trough trough group consisting of at least one of the plurality of trough troughs is provided with a pressure gauge for measuring the pressure in the space covered by the hood and the flow control valve,
Preferably, the control device is configured to control the flow rate adjustment valve to increase the flow rate of the exhaust gas for the trough trolley group when the pressure in the space covered by the hood exceeds atmospheric pressure, based on the pressure value obtained from the pressure gauge.

(5) Furthermore, in any of the above descriptions (1) to (4), it is preferable that a gas inlet pipe is further provided, which is connected to the hood and draws air into the space covered by the hood.

(6) Furthermore, in the device described in (5) above, it is preferable that the gas inlet pipe is provided with a check valve to prevent the flow of gas from the space covered by the hood toward the outside.

(7) Furthermore, in the case described in (5) or (6) above, it is preferable that the inner diameter, the length of the portion within the hood, and the wall thickness of the gas inlet pipe are all within a predetermined range.

According to the present invention, it is possible to maintain a stable negative pressure throughout the entire space between the trough trough and the hood. Even if the trough trough sidewalls sink or deform due to aging or other factors, creating a gap between the trough trough and the hood, it is possible to prevent gas and dust from leaking out of the system through the seal between the trough trough side (movable side) and the hood side (fixed side).

This is an explanatory diagram of the supply and exhaust device for a sintered ore cooler according to an embodiment of the present invention. This is an explanatory diagram of another embodiment of the supply and exhaust system for a sintered ore cooler according to an embodiment of the present invention (Modification 1). Figure 2 is an explanatory diagram illustrating the overall configuration of the intake and exhaust system for the sintered ore cooler. This is an explanatory diagram of another embodiment of the supply and exhaust system for a sintered ore cooler according to an embodiment of the present invention (Modification 2). This is an explanatory diagram of another embodiment of the supply and exhaust system for a sintered ore cooler according to an embodiment of the present invention (Modification 3).

As shown in Figure 1, the supply and exhaust device 3 of the sintered ore cooler 1 according to this embodiment includes a cooling gas pumping device 7 for supplying cooling gas to the lower part of the trough carriage 5, an exhaust gas suction device 9 for sucking in exhaust gas and discharging it to the outside, and a control device 11 for controlling the flow rate of the cooling gas and the flow rate of the exhaust gas. In this embodiment, it is a DCS (Distributed Control System).
The configuration of each device will be described in detail below.

<Sintered Ore Cooler>
The sintered ore cooler 1 stacks sintered ore 15, which has been sintered in a sintering machine, on a plurality of trough troughs 5, at least a portion of which is covered by a hood 13, and continuously cools the sintered ore 15 by passing cooling gas through the layers of sintered ore 15 while moving the plurality of trough troughs 5.

The trough bogie 5 is equipped with wheels 17, a trough 19, an inner side wall 21 and an outer side wall 23, a wind box 25, and a ventilation plate 27, with crushed sintered ore 15 stacked above the ventilation plate 27.
The trough carriage 5 moves along the rails (not shown) within a circularly partitioned area, from the ore supply unit side to the ore discharge unit side.
A sealing mechanism 28 is provided between the fixed hood 13 and the movable trough bogie 5, and this part constitutes the sealing portion.

<Cooling gas pumping system>
The cooling gas pumping device 7 has a pumping pipe 29 equipped with a cooling gas flow meter F1 for measuring the flow rate of the cooling gas, and is for supplying cooling gas to the lower part of multiple trough trolleys 5.
Upstream of the pressure pipe 29 is a supply blower 8 for supplying cooling gas under pressure. Downstream of the supply blower 8 is connected to a fixed annular air duct 31, as shown in Figure 1. The fixed annular air duct 31 is connected to a movable annular air duct 35 via a water seal box 33, and the movable annular air duct 35 is connected to the inner side wall 21 via a connecting air duct 37.

The cooling gas supplied from the pressure pipe 29 to the fixed annular air duct 31 is sealed by the water seal box 33 and supplied to the wind box 25 via the movable annular air duct 35 and the connecting air duct 37.

The measured value from the cooling gas flow meter F1 installed in the pressure pipe 29 is input to the control device 11.

<Exhaust gas suction device>
The exhaust gas suction device 9 has an exhaust pipe 41 equipped with an exhaust gas flow meter F2 for measuring the flow rate of exhaust gas, and is designed to suck exhaust gas from the space covered by the hood 13 and discharge it to the outside. The exhaust pipe 41 is equipped with a flow control valve 39 for adjusting the flow rate of exhaust gas.
A discharge blower 10 is provided downstream of the exhaust pipe 41 to draw in and discharge exhaust gas. The measured value from the exhaust gas flow meter F2 installed on the exhaust pipe 41 is also input to the control device 11.

<Control device>
The control device 11 is configured to control the flow control valve 39 so that the flow rate of the cooling gas is less than the flow rate of the exhaust gas.
Specifically, the measured values from flow meters F1 and F2 are input, and based on these measured values, the flow control valve 39 is controlled so that the flow rate of exhaust gas flowing through the exhaust pipe 41 is greater than the flow rate of cooling gas supplied from the pressure pipe 29.

When exhaust gas from inside the hood 13 is drawn in via a dust collector or the like, the suction force of the exhaust gas is weak in areas far from the piping connected to the hood 13, and conditions for gas and dust leakage are likely to occur when the pressure inside the hood becomes higher than atmospheric pressure.
Therefore, the control device 11 controls the flow rate of the cooling gas and the flow control valve 39 so that the flow rate of the exhaust gas is less than the flow rate of the exhaust gas, thereby making the pressure inside the hood lower than atmospheric pressure.

As described above, the exhaust and supply system 3 of the sintered ore cooler according to this embodiment makes it easy to maintain a stable negative pressure throughout the entire space between the trough carriage 5 and the hood 13. Even if the side walls 21 and 23 of the trough carriage 5 sink or deform due to aging or other factors, reducing the sealing effect of the sealing mechanism and creating a gap between the trough carriage 5 and the hood 13, it is possible to prevent gas and dust from leaking out of the system from the sealing portion between the trough carriage 5 side (movable side) and the hood 13 side (fixed side).

[Variation 1]
The formation or expansion of gaps between the trough bogie 5 and the hood 13 due to changes over time may occur randomly with respect to the trough bogie 5.
In this case, as shown in Figures 2 and 3, each individual trough trough 5 or a group of trough troughs 5 is provided with a pressure gauge P and a flow control valve 39 for measuring the pressure in the space covered by the hood 13. The pressure value measured by the pressure gauge P is input to the control device 11, and the flow control valve 39 is adjusted to increase the flow rate of exhaust gas in the locations (trough trough groups) where the pressure in the space covered by the hood 13 exceeds atmospheric pressure. This makes it possible to prevent leakage at specific points and is more economical.
Furthermore, if the total amount of exhaust gas flow collected from each hood 13 does not satisfy the relationship (total amount of exhaust gas flow) > (cooling gas flow), it is preferable to increase the opening of the exhaust gas flow control valve starting with the one with the smallest pressure difference between atmospheric pressure and the internal pressure of the hood 13 (atmospheric pressure - internal pressure of the hood 13).

[Modified example 2]
If the exhaust gas flow rate is excessive compared to the cooling gas flow rate, the pressure difference between the space covered by the hood 13 and the outside will increase, potentially leading to deformation of the seal, intake of outside air, and deformation of the equipment. Furthermore, if there is a large intake of outside air from the seal, the exhaust heat recovery temperature will decrease, hindering heat exchange in the boiler.
Therefore, as shown in Figure 4, by providing a gas inlet pipe 43 in the hood 13 that takes in air into the space covered by the hood 13, when the exhaust gas flow rate temporarily becomes excessive, outside air can be actively drawn in through the gas inlet pipe 43, reducing the pressure difference between the inside and outside of the hood 13 and maintaining the inside of the hood 13 at a constant pressure close to atmospheric pressure.

When a gas inlet pipe 43 is provided, by ensuring that a certain length or more of the gas inlet pipe 43 is contained within the hood 13, the incoming outside air is heated as it flows through the gas inlet pipe 43 contained within the hood 13, thereby suppressing the temperature drop of the exhaust gas.
It is desirable that the inner diameter of the gas inlet pipe 43, the length of the portion inside the hood 13, and the wall thickness are all within a predetermined range. For example, it is desirable to set the dimensions to be within the range of inner diameter: 0.1 to 0.5 m, length of the portion inside the hood 13: 0.5 m or more, and wall thickness: 5 mm or more. If the inner diameter is too small, the pressure loss when the pipe flows in will increase, and if it is too large, it may cause a momentary drop in exhaust gas temperature. Also, if the length of the portion inside the hood 13 is too short, the incoming outside air will not be sufficiently heated. Furthermore, having a wall thickness of a certain degree or more ensures that there is enough heat capacity to store heat during normal operation when the airflow rate through the gas inlet pipe 43 is low, and greatly reduces the effect of suppressing the temperature drop in the space covered by the hood 13 when the amount of outside air flowing in from the gas inlet pipe 43 increases. The upper limits of the length and wall thickness of the portion of the inlet pipe 43 inside the hood 13 should be set to a reasonable range considering the weight and other factors according to the inner diameter of the inlet pipe 43.
Furthermore, a check valve 45 or a cyclone (not shown) may be installed at the suction end of the gas inlet pipe 43 to prevent gas from flowing outwards from the space covered by the hood, thereby preventing leakage of gas and dust to the outside of the system even when the pressure inside the hood 13 fluctuates locally.

[Modification 3]
The seal at the bottom of the trough trough 5 cannot completely prevent cooling gas leakage. In particular, cooling gas leakage becomes more pronounced as the equipment deteriorates over time.
Therefore, by taking into account the amount of cooling gas leakage and controlling the system so that (exhaust gas flow rate) ≥ (cooling gas flow rate) - (leakage rate), the minimum value of the exhaust gas flow rate can be reduced. This reduces the exhaust gas flow rate, leading to a reduction in electricity costs for exhaust blowers and other equipment, making it more economical.

The amount of air leakage may be calculated from known data using a formula that takes the cooling gas flow rate and pressure as variables. Alternatively, as shown in Figure 5, an anemometer 47 may be installed at the leakage point, such as the seal, to measure the wind speed, and the measured value may be input to the control device 11 to convert the wind speed into the amount of air leakage.
In any case, the control device 11 is configured to control the exhaust gas flow rate control valve 39 based on the amount of air leakage so that the relationship (flow rate of exhaust gas) ≥ (flow rate of cooling gas) - (amount of air leakage) is satisfied.

Although the present invention has been described above using embodiments and modifications, the present invention is not limited to the configurations of these embodiments and modifications. The scope of the present invention is determined based on the description in the appended claims, and within that scope, all configurations that omit, modify, or improve upon some of the components shown in the embodiments and modifications are included in the present invention.

For example, in the above embodiment, the flow control valve 39 is provided only in the exhaust pipe 41, but the flow control valve may also be provided in the pressure pipe, or in both the pressure pipe and the exhaust pipe.

Furthermore, in the above embodiment, the control device 11 is configured to control only the exhaust gas suction device 9 (flow rate control valve 39). However, in the present invention, the control device may be configured to control the cooling gas pumping device so that the flow rate of the cooling gas is less than the flow rate of the exhaust gas, or it may be configured to control both the cooling gas pumping device and the exhaust gas suction device.

Furthermore, while the above embodiment demonstrated a preferred configuration for achieving high-precision control by providing a cooling gas flow meter in the pressure pipe and an exhaust gas flow meter in the exhaust pipe, and controlling the flow control valve based on these measured values, the present invention may also be configured to control at least one of the supply blower and the discharge blower so that the flow rate of the cooling gas is less than the flow rate of the exhaust gas.

1. Sintered ore cooler 3. Supply and exhaust system 5. Trough trolley 7. Cooling gas pressurizing system 8. Supply blower 9. Exhaust gas suction system 10. Discharge blower 11. Control device 13. Hood 15. Sintered ore 17. Wheels 19. Trough 21. Inner side wall 23. Outer side wall 25. Wind box 27. Ventilation plate 28. Seal mechanism 29. Pressurizing pipe 31. Fixed annular air duct 33. Water seal box 35. Movable annular air duct 37. Connecting air duct 39. Flow control valve 41. Exhaust pipe 43. Gas inlet pipe 45. Check valve 47. Anemometer F1, F2 Flow meter P. Pressure gauge

Claims (5)

A supply and exhaust system for a sintered ore cooler, which stacks sintered ore sintered in a sintering machine on a plurality of trough troughs, each of which is covered by a hood at least on top, and continuously cools the sintered ore by passing a cooling gas through the layers of sintered ore while moving the plurality of trough troughs,
A cooling gas pumping device for supplying the cooling gas to the lower part of the plurality of trough trolleys,
An exhaust gas suction device for drawing exhaust gas from the space covered by the aforementioned hood and discharging it to the outside,
A control device configured to control at least one of the cooling gas pumping device and the exhaust gas suction device such that the flow rate of the cooling gas becomes less than the flow rate of the exhaust gas and the pressure inside the hood becomes lower than atmospheric pressure,
Equipped with,
The cooling gas pumping device has a pumping pipe equipped with a cooling gas flow meter for measuring the flow rate of the cooling gas,
The exhaust gas suction device has an exhaust pipe equipped with an exhaust gas flow meter for measuring the flow rate of the exhaust gas,
A flow control valve is provided in at least the exhaust pipe of the pressure pipe and the exhaust pipe.
Each trough trough group, consisting of at least one of the aforementioned plurality of trough troughs, is provided with a pressure gauge for measuring the pressure in the space covered by the hood and the flow control valve.
The control device is configured to control the flow rate adjustment valve based on the measured values of the cooling gas flow meter and the exhaust gas flow meter, and is configured to control the flow rate adjustment valve to increase the flow rate of the exhaust gas for the trough trough group when the pressure in the space covered by the hood exceeds atmospheric pressure, based on the pressure value obtained from the pressure gauge . The air supply and exhaust system for a sintered ore cooler according to claim 1, characterized in that the control device is configured to control the flow rate control valve based on the amount of air leakage so that the relationship (flow rate of exhaust gas) ≥ (flow rate of cooling gas) - (amount of air leakage) is satisfied. The sintered ore cooler supply and exhaust device according to claim 1 or 2 , further comprising a gas inlet pipe connected to the hood and for drawing air into the space covered by the hood. The sintered ore cooling machine supply and exhaust device according to claim 3 , characterized in that the gas inlet pipe is provided with a check valve that prevents the flow of gas from the space covered by the hood toward the outside. The gas inlet pipe is characterized in that its inner diameter, the length of the portion inside the hood, and its wall thickness are all within a predetermined range, as described in claim 3 , for the supply and exhaust device of a sintered ore cooler.