JPS613819A - Hermetic type waste gas treating device provided with emergency air intake valve - Google Patents

Abstract

PURPOSE:To prevent the abnormal negative pressure in a hermetic type waste converter gas treating device by providing an air intake port to the hood of said device and providing an air intake valve thereto so as to open the air intake port when a valve disk falls. CONSTITUTION:The emergency air intake valve 14 is attached to the hood 3 of the hermetic type waste converter gas treating device. More specifically, a valve box 16 having an aperture 17 in the upper part is connected to the air intake port 15 attached to the hood 3. The aperture 17 is hermetically closed by a valve disk 19 which is adapted to fall under the guide of a guide rod 18. In the event of the outbreak of an emergency state when an induced draft fan 7 or other control system stops on account of, for example, service interruption or the like, the oxygen blowing is stopped by the signal thereof and a cylinder 20 is commanded as well, by which the detaining state is released. Some negative pressure is generated in such a case when the oxygen blowing stops but the negative pressure acts as the force to suck the disk 19 and increases the initial falling speed of the disk 19 by which the aperture 17 is instantaneously opened to suck the external air.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is intended for emergency use in order to prevent abnormal negative pressure during an emergency shutdown in a closed converter exhaust gas treatment equipment that operates in a sealed or nearly sealed state. 〇 Regarding converter exhaust gas treatment equipment equipped with an air intake valve (prior art and its problems) The outline of the converter exhaust gas treatment equipment is explained with reference to Fig. 1. Included lance 1
3. Blow in pure oxygen to refine. During this blowing, carbon in the hot metal reacts with oxygen blown in from the lance 13, and a large amount of high-temperature CO gas is generated. Gas with low CO concentration at the beginning and end of the blowing is drawn into the hood 3 by the induced blower T, cooled by the hood 3 and cooler 4, and removed by dust removers 5 and 6. , and is then dissipated during combustion at the top through a dispersion tower 8. Gas with a high concentration of CO at the peak of blowing will switch the damper 10 and shut off the water seal valve 11.
It is collected as a valuable gas through the duct 12 into a gas holder (not shown).

Moreover, CO gas is not only extremely dangerous as it can cause CO poisoning if it leaks outside, but there is also the danger of it reacting with the outside air and combusting rapidly. Therefore, the furnace opening of converter 1 and the hood 3
A skirt 2 that can be raised and lowered is provided between the
C.
This prevents O gas from leaking out and outside air from entering into the skirt 2.

In this converter exhaust gas treatment device, the converter operation is performed in the following three steps. That is, a pig iron receiving process in which hot metal produced in a blast furnace (not shown) is injected into the converter 1, a blowing process in which pure oxygen is blown into the hot metal injected into the converter 1 to refine it, and a It is carried out in three steps: the tapping step in which molten steel is discharged from the converter 1.

Of the three processes mentioned above, the pig iron receiving process and the tapping process are performed by tilting the converter 1, so the skirt 2 is raised, and in the blowing process, the skirt 2 is lowered, and the opening of the converter 1 and the skirt are lowered. 2
However, the furnace mouth of the converter 1 is not always flat due to the accumulation of slag, and the skirt 2 and the furnace mouth do not come into close contact. (possible), so it was closed with a certain amount of gap. Therefore, some outside air entered through the gap, and a drop in temperature of 0.08 degrees could not be avoided.

On the other hand, as it is now required to recover gas with a high CO# content (purity), if the space between the opening of the converter 1 and the skirt 2 is completely sealed or close to completely sealed, and an emergency shutdown is performed. , there are new technical problems.

Oxygen injection is stopped as a normal emergency stop procedure.

Therefore, the amount of gas generated from the converter 1 decreases rapidly.

In the conventional open type, outside air is sucked through the gap between the furnace opening of the converter 1 and the skirt 2 by an amount commensurate with the reduction in the amount of gas generated, and the amount of air is drawn in to compensate for the amount of gas induced by the induced blower T. The amount of gas was secured and the pressure inside the exhaust gas treatment equipment was maintained, but in the case of a closed type, there is no outside air suction or very little if any, so the pressure inside the exhaust gas treatment equipment can instantly drop to a negative level. However, there is a problem in that the exhaust gas treatment device is damaged due to this negative pressure.

For example, if there is instantaneous negative pressure, if outside air enters through the seal, or if there is a breakage and outside air enters, a major accident such as an explosion may occur. If there is an ignition source, it will instantly combust and explode. ) In the case of the conventional open type, outside air is sucked in (through the gap between the furnace mouth of the converter 1 and the skirt 2), and high temperature CO gas reacts with the 02 in the sucked outside air (CO gas (combustion of CO), which produces CO gas, which is first drawn in and cooled.
By interposing a CO and gas layer (this is called an inert gas layer) between the gas and the outside air that is sucked in later,
Although contact between the cooled CO gas and the subsequently sucked-in outside air is prevented, and there is no risk of explosion, there is a problem that it is not dense and there is a high risk of explosion.

Also, at the beginning and end of blowing, the amount of gas generated from the converter 1 is small and the CO concentration is low, so it is not recovered but is burned at the top through the chimney and dissipated. When there is an emergency stop, the pressure inside the exhaust gas treatment equipment suddenly becomes negative, and the gas flow velocity in the chimney decreases, outside air enters the chimney, backfires, and combustion occurs inside the chimney. There is a risk of an explosion.

The instantaneous negative pressure that occurs due to the use of a closed type system may cause a number of unexpected technical problems. The reality is that the development of devices is urgently needed.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and provides a closed converter exhaust gas treatment device equipped with an emergency air valve to prevent abnormal negative pressure even in the event of an emergency shutdown. The purpose is to

(Structure of the Invention) The closed type converter exhaust gas treatment device of the present invention is provided with an air intake in the hood, which is a high-temperature part of CO gas, and a valve box with an open top connected to the air intake. The upper opening of the valve body is sealed, and the air intake port is opened to prevent abnormal negative pressure by sucking in outside air and allowing the valve body to fall while being guided by a guide rod installed vertically inside the valve box. Features.

(Example) An example of the closed converter exhaust gas treatment apparatus of the present invention will be described with reference to the drawings. In FIG. 1, 14 is an emergency air intake valve attached to the hood 3. FIG. 2 is a longitudinal sectional view showing details of this emergency air intake valve 14, and 15 is an air intake port attached to the hood 3. A valve box 16 having an opening 11 at the top is connected to the air intake port 15 . 19 is a valve body that seals the opening 17, and is guided by a guide rod 18 so as to fall down.

That is, the valve body 19 is provided with a valve stem 23, and this valve stem 2
A locking member 22 provided at 3 is locked to an arm 21 driven by a cylinder 20. In this state, by operating the cylinder 20, the locked state is released and the valve body 19 falls.On the other hand, in order to seal the opening 17, the valve body 19 is opened by operating the cylinder 20. It is best to closely follow.

In this embodiment, the valve body 19 is locked to the cylinder 20 via the locking member 22, but the valve body 19 may be tightly attached to the bottom opening portion 17 using a magnet, for example. The point is that if the valve body 19 is configured so that it can fall, it will fall off.

Next, the operation of this embodiment configured as described above will be explained.

- Yes.

For example, if an induced fan is used due to a power outage, etc.? h Other control systems will stop (the induced blower is due to inertia) and will not stop suddenly. ) When such an emergency situation occurs, the oxygen injection is stopped based on the signal, and a command is also given to the cylinder 20 to release the locked state.

In this case, the negative pressure becomes somewhat negative when the oxygen injection is stopped, but this negative pressure acts as a suction force on the valve body 19, and the initial speed at which the valve body 19 starts to fall (under its own weight) after the lock is released is In order to speed up the process, the time from release of the latch to the start of the fall is shortened, and the opening 17 is instantly opened to suck in outside air. 0.0 in the air. Burns CO gas! ? When a gas layer is generated, an amount of gas commensurate with the amount of gas sucked by the induced blower γ is obtained, and no abnormal negative pressure occurs in the exhaust gas treatment device.

Further, in normal operation, the valve body 19 tightly seals the opening 17, and high-purity CO gas is recovered.

(Effects of the Invention) The closed type converter exhaust gas treatment device according to the present invention described in detail above has an air intake port provided in the hood, and the air intake port includes:
The air suction valve is designed to open the air suction port by dropping the valve body, so even if oxygen injection is stopped in an emergency, the air suction port can be opened quickly and outside air can be sucked in, reducing exhaust gas. Abnormal negative pressure within the processing device can be prevented.

Therefore, there is no risk of equipment damage, explosion due to insufficient inert gas generation, backfire in the chimney, etc., making it possible to create a highly safe closed type converter exhaust gas treatment equipment. This has excellent effects such as making recovery possible.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1 is a schematic diagram showing the entire converter exhaust gas treatment device, and FIG. 2 is a vertical sectional view of the emergency air intake valve.

Claims (1)

[Claims] An air intake provided in the hood of a converter exhaust gas treatment equipment, a valve box connected to the air intake with an open top, and a guide rod that seals the top opening of the valve box and is vertically installed inside the valve box. Closed type converter exhaust gas treatment equipment equipped with an emergency air intake valve consisting of a valve body that falls along the