JP2005214547A - Damper and its opening and closing control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform the gas control and emergency blowoff by a common device while preventing environmental pollution. <P>SOLUTION: This damper 1 is mounted on the way of a blowoff duct 31 of the waste heat recovering equipment to control the opening and closing of a blowoff duct 31 by opening and closing a plurality of damper blades 3, 4 mounted inside of a cam body 2. As one duct can be used in common as the blowoff duct 31 and an emergency blowoff duct 33, the plurality of damper blades 3, 4 are divided into two groups respectively that for exhausting 3 and that for emergency blowoff 4 to have different opening and closing speeds. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a duct that is provided in a duct through which a large amount of gas flows, such as a waste heat recovery facility such as a sinter ore production facility and a melting furnace, and a method for controlling the opening and closing of the duct that can instantaneously change the gas flow It is.

For example, in a sinter production facility, a waste heat recovery facility may be provided in the gas processing system. An example is shown in FIG.
FIG. 6 is a diagram showing the equipment flow of the sinter ore production facility. The product obtained by firing and reducing iron ore by the sinter machine 21 is the cooling gas sent from the cooling blower 23 by the sinter ore cooler 22. And then conveyed to a predetermined place by a belt conveyor or the like.

  By the way, in the facility shown in FIG. 6, the exhaust gas generated when being baked and reduced by the sintering machine 21 passes through a pollution prevention device 24 such as a dust collector or desulfurization / denitration removal equipment, for example, and a dust collecting fan 25. Is discharged from the stack 26. In some cases, the pollution prevention device 24 and the dust collection blower 25 are reversely arranged. At this time, the dust collection blower 25 becomes a push-in blower.

The sinter cooler 22 gas-cools a high-temperature product as described above, and performs waste heat recovery using the cooled gas. This waste heat recovery mainly obtains steam, and the exhaust gas after the heat recovery is circulated through the exhaust gas circulation duct 27 and used again as a cooling gas in the sinter cooler 22.
Japanese Patent Publication No.58-15709

  When the waste heat recovery boiler 28 is stopped while the sinter cooler 22 is in operation, the outside air suction damper 29 and the exhaust damper 30 are opened to discharge the exhaust heat. In such equipment, the exhaust gas circulation duct 27 is used. If partition plates or the like are inserted on the inlet side and the outlet side of the waste heat recovery boiler 28, the waste heat recovery boiler 28 can be repaired while cooling the sintered ore.

  In addition, it is possible to prevent the heat source of the waste heat recovery boiler 28 from being excessive by using the exhaust damper 30. That is, the temperature of the exhaust gas flowing into the waste heat recovery boiler 28 can be controlled by appropriately adjusting the opening degree of the exhaust damper 30.

  However, in the exhaust / breathing method shown in FIG. 6, since exhaust gas is diffused from the exhaust damper 30 to the atmosphere, pollution is generated if there is much dust in the exhaust gas. Therefore, it is desirable to exhaust and ventilate by the equipment flow as shown in FIG.

  The facility flow shown in FIG. 7 is provided with the air discharge duct 31 so as to guide the exhaust heat dissipated from the exhaust damper 30 to the atmosphere in FIG. 6 to the front stage of the pollution prevention device 24. Thus, even if the exhaust gas temperature to the waste heat recovery boiler 28 becomes excessive, control can be performed without any problem.

In such a sintering facility, the amount of gas flowing in the exhaust gas circulation duct 27 may exceed 500 km ³ N / hour, and even if the wind speed is designed at about 20 m / second, the cross-sectional area of the exhaust gas circulation duct 27 is excellent. there is a case in which more than 15m ² in.

  In order to block all the exhaust gas flowing through the exhaust gas circulation duct 27 having such a large cross-sectional area and reaching the waste heat recovery boiler 28, the discharge duct 31 also needs to have a cross-sectional area equivalent to that of the exhaust gas circulation duct 27.

  As shown in FIG. 8, the damper 40 installed in the duct having such a large cross-sectional area is arranged inside the can body 41 so that a plurality of damper blades 42 can be rotated around the shaft 42a. Then, all these shafts 42a are rotated in synchronization by the actuator 44 via the link mechanism 43, thereby opening and closing the plurality of damper blades 42. The opening and closing speed is 30 from fully closed to fully open. Something as slow as a second is used.

  By the way, in a sintering facility, when a heat exchange tube (generally referred to as a finned tube) built in the waste heat recovery boiler 28 is blocked by dust or the like, the exhaust gas may be suddenly shut off. is there.

  If the opening speed of the exhaust damper 30 is slow during such an emergency shut-off, the pressure of the exhaust gas remains in the path, and for example, the cooling blower 23, the sintered ore cooler 22, and the exhaust gas circulation duct 27 may be damaged. .

  In order to prevent such a problem, it is necessary to construct an equipment flow as shown in FIG. In the example shown in FIG. 9, in order to control the amount of exhaust gas flowing into the waste heat recovery boiler 28, an exhaust damper 30 and a discharge duct 31 that perform relatively slow discharge, and an emergency discharge that discharges in an emergency The damper 32 and the emergency air discharge duct 33 are arranged in parallel.

  In the equipment having the route shown in FIG. 9, the emergency air discharge damper 32 is normally completely closed, and the control of the exhaust gas inflow amount to the waste heat recovery boiler 28 is approximately 30 seconds from the fully closed to the fully opened. This is done with the exhaust damper 30 that opens at. Note that the time required for opening and closing is that when a commercially available motor cylinder is used.

  On the other hand, the emergency air discharge duct 33 releases the trapped pressure, and as an experience, it may be about 1/3 of the flow path area of the exhaust gas circulation duct 27 and the air discharge duct 31. Further, in the example shown in FIG. 9, the opening / closing speed of the emergency blow-off damper 32 does not cause a problem if the time from the fully closed state to the fully open state is 3 seconds or less.

  However, as shown in FIG. 9, when the exhaust damper 30 and the emergency wind damper 32 are arranged in parallel, a large installation place is required and the construction cost is enormous, resulting in a facility with a very poor construction yield. Become.

As an emergency exhaust device, a technique is disclosed in which a relief damper is provided that detects and opens the pressure in the duct.
JP 54-45410 A

  However, the technique disclosed in Patent Document 2 is also considered to have the same opening / closing speed of the relief damper as the opening / closing speed of the conventional damper, and cannot be used for solving the problems of the present invention.

Also disclosed is a technology that is equipped with a bypass flue and an air flow adjustment damper to guide the exhaust gas of the electrostatic precipitator that constitutes the sintered exhaust gas treatment device to the chimney, and to reduce the negative pressure load on the duct at startup Has been.
JP 2001-317878 A

  However, the technique disclosed in Patent Document 3 disperses the exhaust gas that should originally be purified without treatment, and is substantially difficult to realize and adopt, and the damper structure opens urgently. However, the pressure and air volume are gradually controlled, and the problem that the present invention aims at performing gas control and emergency air blowing with the same apparatus cannot be solved while preventing pollution.

  The problem to be solved is that gas control and emergency ventilation cannot be performed with the same device while preventing pollution.

The damper of the present invention is
A damper that is disposed in the middle of a discharge duct of a waste heat recovery facility and that controls opening and closing of the discharge duct by opening and closing a plurality of damper blades provided inside the can body,
In order to make it possible to use both the discharge duct and the emergency discharge duct as a single duct, it is most important to divide the plurality of damper blades into two groups, one for exhaust and one for emergency discharge. Main features.

  In the damper of the present invention, when an air cylinder or a weight drop is used as an operating source of the emergency air blowing damper blade group, the emergency air blowing damper blade group is fully closed to fully opened in about 3 seconds. Will be able to open.

Further, the opening / closing control of the damper according to the present invention includes:
The exhaust damper blade group always performs open / close control according to the operating state of the waste heat recovery equipment, while the emergency blower damper blade group is always fully closed and only in an emergency. Fully open rapidly. This is the damper open / close control method of the present invention.

  According to the present invention, gas control and emergency emergency blow can be performed with a small-scale facility configuration while preventing pollution.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIG. The equipment flow in which the damper of the present invention is installed is the same as that in FIG.

  FIG. 1 is a diagram showing a schematic configuration of the damper 1 of the present invention, and the can body 2 has the same configuration as the can body 41 in the conventional damper 40 shown in FIG. It is about 4/3 times the can body 41. In the damper 1 of the present invention, the damper blades are, for example, five exhaust damper blades 3 (corresponding to the exhaust dampers in FIG. And the three emergency blow-off damper blades 4 (corresponding to the emergency blow-off damper shown in FIG. ) And divided into two groups. The cross-sectional area of the can body 2 may be approximately the same as that of the conventional can body 41, and the area ratio of the exhaust damper blade 3 and the emergency air discharge damper blade 4 may be set to be approximately 3: 1.

  These damper blades 3 and 4 are attached to the can 2 so that they can be freely rotated by shafts 3a and 4a, as in the case of conventional damper blades. Of these, the damper blade 3 for exhaust is always controlled to open and close. In the event of an emergency, there is no need to perform an opening / closing operation in an emergency. On the other hand, the emergency blow-off damper blade 4 is normally closed and is fully opened only in an emergency.

Hereinafter, the damper of the present invention will be described in more detail with reference to FIGS.
FIG. 2 is a detailed view showing a first example in which the operation sources of the exhaust damper blade 3 and the emergency air discharge damper blade 4 are separately provided in the damper 1 of the present invention shown in FIG. The figure shows a total of five damper blades, three blades 3 and two emergency blowout damper blades 4. The number of the damper blades 3 and 4 is not limited as long as the ratio of the cross-sectional areas is as described above.

  Reference numeral 5 denotes an air cylinder, which is an actuator for rapidly opening the emergency blow-off damper blade 4 from a fully closed state to a fully opened state, for example, within 3 seconds. The air cylinder 5 is connected to the shaft 4a of the two emergency blow-off damper blades 4 by the link mechanism 6, and at the time of emergency blow-off, the two emergency blow-off damper blades 4 are moved by the protruding operation of the rod of the air cylinder 5. In synchronism with each other, it is rapidly rotated from the fully closed state to the fully open state to be opened.

  A motor cylinder 7 is an actuator for controlling the opening and closing of the exhaust damper blade 3 and opens the exhaust damper blade 3 from a fully closed state to a fully opened state in about 30 seconds, for example. The motor cylinder 7 is also connected to the shaft 3a of the three exhaust damper blades 3 by the link mechanism 6 similar to the above, and the three exhaust damper blades 3 are operated by the retracting operation of the rod of the motor cylinder 7. According to the state, the opening / closing control is performed synchronously.

  The damper 1 of the present invention shown in FIG. 3 is obtained by changing the shape of the can body 2 from a rectangular shape in front view in FIG. 2 to a circular shape in front view in order to be installed in a duct having a circular cross section. With the change, only the size and number of the damper blades 3 and 4 are changed, and the configuration is the same as that shown in FIG.

  As described above, the damper 1 of the present invention includes an exhaust damper blade 3 that is always opened and closed in accordance with the operating state, and an emergency air discharge damper that is normally fully closed and is fully open only during emergency air discharge. The vane 4 is attached to the same can body 2, and the exhaust damper blade 3 can be controlled to open and close at a normal speed of about 30 seconds from fully closed (fully open) to fully open (fully closed). It can be opened and closed at a speed of about 3 seconds from fully closed (fully open) to fully open (fully closed).

  It goes without saying that the drive source for opening and closing the emergency blow-off damper blade 4 is not limited to the above-described air cylinder 5 as long as it can be opened from the fully closed state to the fully open state in about 3 seconds. For example, a weight using a weight as shown in FIG. 4 may be used. Hereinafter, an example using a weight will be described.

  FIG. 4 is a schematic configuration diagram showing the damper 1 using the weight 11 as an operation source of the emergency blow-off damper blade 4. The can body 2, the exhaust damper blade 3, the emergency blow-off damper blade 4, the shaft Since 3a, 4a, etc. are the same as those in FIG. 2 described above, only the opening / closing mechanism of the emergency blow-off damper blade 4 will be described below.

  A pulley 8 is attached to the shaft 4 a of the emergency air blowing damper blade 4. The shaft 4 a to which the pulley 8 is attached is connected to the motor 10 through a clutch 9. Reference numeral 11 denotes a weight wound around the pulley 8 by a wire rope 12. When an emergency wind blows, a weight is given to the clutch 9 to release the clutch 9 so that the weight 11 falls from the previous position. Then, the shaft 4a is rotated via the pulley 8 to rapidly open the emergency blow-off damper blade 4 from the fully closed state to the fully open state.

  By the way, when the weight 11 is used as an operating source, for example, when the lower side of the weight 11 is a passage, a man-made disaster may occur when the wire rope 12 hanging the weight 11 is cut. There is danger in practical use.

  Therefore, in the example shown in FIG. 4, an air cylinder 13 having a stopper 14 installed at the rod end is horizontally installed near the bottom surface of the suspended weight 11, and the emergency blow-off damper blade 4 is closed. In this case, the stopper 14 is inserted into the bottom surface of the weight 11 and the weight 11 is supported by the stopper 14 to ensure safety. In the event of an emergency wind, the air cylinder 13 is released simultaneously with the release of the clutch 9. The rod is retracted so as not to prevent the weight 11 from falling. Note that the safety can be further enhanced by sounding an alarm during this emergency wind. After the emergency is released, the clutch 9 is connected, and then the motor 10 is operated to close the emergency blow-off damper blade 4.

FIG. 5 shows an example of a control system flow of the emergency blow-off damper blade 4 when the damper 1 of the present invention shown in FIGS. 2 to 4 is incorporated in a sintering facility or the like.
As shown in this control system, in the damper 1 of the present invention, the exhaust damper blade 3 group always performs opening and closing control according to the operating state of the waste heat recovery facility, while the emergency air discharge damper blade 4. The group is always fully closed and is rapidly fully opened only in an emergency such as when an abnormality of the waste heat recovery boiler 28 is detected. Needless to say, normal operation is continued except in an emergency.

  In this emergency, the operation of the cooling blower 23 continues as usual only by performing the emergency full opening of the emergency blowout damper blades 4 group. Then, when the pressure abnormality in the exhaust gas circulation duct 27 is resolved by such emergency control, the operation of the sinter cooler 22 is continued and the equipment such as the waste heat recovery boiler 28 is inspected. Do.

  On the other hand, if the pressure abnormality in the exhaust gas circulation duct 27 continues, it is determined whether or not to stop the cooling fan 23. If so, recovery work such as repair of the waste heat recovery boiler 28 is performed. And resume operation after the recovery work is complete. When the cooling fan 23 is not stopped, the operation of the sinter cooler 22 is continued and the equipment such as the waste heat recovery boiler 28 is inspected, as in the case where the pressure abnormality in the exhaust gas circulation duct 27 is eliminated. I do.

  2 and 3 shown in Table 1 below were installed in the equipment flow shown in FIG. 7, but the equipment was not able to be used in equipment such as a waste heat recovery boiler. Even if a serious malfunction occurred, no accidents such as damage occurred in any part of the entire facility.

  The present invention is not limited to the above example, and other claims may be used as long as the operation of the damper blade for emergency ventilating can be rapidly opened from fully closed to fully opened for about 3 seconds. Needless to say, the embodiment may be appropriately changed within the scope of the technical idea described in the section.

  The present invention described above is not limited to the waste heat recovery facility of the sinter production facility, and can be applied to any facility as long as it is a facility that instantaneously changes the gas flow in a duct through which a large amount of gas flows. .

It is the figure which showed schematic structure of the damper of this invention. FIG. 2 is a detailed view showing a first example in which the operation source of the exhaust damper blade and the emergency blow-off damper blade are separately provided in the damper of the present invention shown in FIG. 1, (a) is a front view, (b) ) Is a side view. In FIG. 2, it is the same figure as FIG. 2 at the time of making the shape of a can body into a circular cross section. It is the schematic block diagram which showed the damper which used the weight as an action | operation source of the damper blade | wing for emergency air blowing. It is the figure which showed an example of the control system flow of the damper blade | wing for emergency ventilating at the time of incorporating the damper of this invention shown in FIGS. It is the figure which showed an example of the equipment flow of a sintered ore manufacturing equipment. In the facility flow of FIG. 6, a discharge duct is provided to guide the exhaust heat from the exhaust damper to the front stage of the pollution control device. It is the schematic which shows the structure of the conventional damper, (a) is a perspective view, (b) is a figure explaining the action | operation mechanism of a damper blade | wing. In the equipment flow of FIG. 7, an exhaust damper and a discharge duct that perform relatively slow discharge, and an emergency discharge damper and an emergency discharge duct that discharges in an emergency are arranged in parallel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Damper 2 Can 3 Exhaust damper blade 3a Axis 4 Emergency blower damper blade 4a Axis 5 Air cylinder 6 Link mechanism 7 Motor cylinder 11 Weight 27 Exhaust gas circulation duct 29 Outside air suction duct 30 Exhaust damper 31 Exhaust duct 32 Emergency Wind damper

Claims (3)

A damper that is disposed in the middle of a discharge duct of a waste heat recovery facility and that controls opening and closing of the discharge duct by opening and closing a plurality of damper blades provided inside the can body,
A damper characterized in that the plurality of damper blades are divided into two groups for exhaust and emergency discharge, and the opening and closing speeds are different.   2. The damper according to claim 1, wherein an air cylinder or a drop of a weight is used as an operating source of the emergency air blowing damper blade group. A method for controlling opening and closing of the damper according to claim 1 or 2,
The exhaust damper blade group is always controlled to open and close according to the operating state of the waste heat recovery equipment, while the emergency blower damper blade group is always fully closed, only in an emergency. A damper open / close control method characterized by rapid full opening.

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