JPS5935564Y2 - Dust intrusion prevention mechanism in furnace measurement equipment - Google Patents

Description

[Detailed description of the invention] This invention relates to a mechanism for preventing the intrusion of dust and furnace gases (hereinafter sometimes referred to as "dust"), which is installed in an in-furnace measurement device that monitors the operation status of a vertical furnace. Specifically, this relates to a dust intrusion prevention mechanism that uses an inert gas purge method and is equipped with a damper that can be opened and closed at the tip of the dust intrusion prevention mechanism, thereby greatly reducing inert gas consumption. It is.

In a vertical furnace, such as a blast furnace, ores and coke are alternately charged, and iron oxides are reduced by high-temperature reducing gas rising from below.

The produced iron and slag are respectively melted and dripped onto the bottom of the furnace.
It is taken out of the furnace intermittently or continuously.

Therefore, the charged ores, etc. (hereinafter sometimes simply referred to as the charge) gradually descend, and new charges are charged in accordance with the descent to perform continuous operation. In order to continue the furnace under stable conditions, it is necessary to detect the rising temperature, flow rate, temperature, composition, etc. of the gas in the furnace, and to accurately understand the descending status of the charge, which requires the use of various measuring devices. is attached to the top of the furnace.

In the following description, a device for detecting the surface layer condition of blast furnace charge (hereinafter referred to as a "measuring device") will be taken up as a representative example, but it is of course applicable to other measuring devices.

However, such a measuring device can only be expected to be effective if it operates smoothly, but a factor that threatens this expectation is the phenomenon of dust entering and accumulating inside the measuring device.

In other words, if dust (hereinafter simply referred to as "dust" means raw material dust) enters and accumulates on the inner periphery of the tip of the measuring device inlet that penetrates the side wall of the blast furnace and opens into the furnace, the measuring device cannot be taken in or out of the furnace. When doing so, there is a risk that dust may get caught between the measuring device and the device's guide port, causing the measuring device to malfunction or become inoperable.

Therefore, in order to avoid such a situation from developing, measuring devices have conventionally been provided with a mechanism to prevent dust from entering.

The basic structure of the dust intrusion prevention mechanism in this measuring device is known as shown in FIG.

In this figure, reference numeral 1 denotes an iron shell constituting a blast furnace, and the inner surface of the iron shell 1 is lined with a refractory material 2.

In the measuring device, a lance 9 is inserted into a lance protection tube 11 that protrudes through the steel shell 1 so as to be able to move forward and backward in the direction of the arrow in the figure.

Reference numeral 6 denotes a wire that is disposed along the lance 9 so as to be movable forward and backward in the direction of the arrow in the figure, and a weight 7 is attached to the tip of the wire that is suspended above the charge 4.

That is, the surface state of the charge 4 can be detected by measuring the hanging distance of the wire 6 while moving the lance 9 and the wire 6 in the direction of the arrow.

On the other hand, as mentioned above, the lance protection tube 11 is attached to the nozzle 1' of the iron skin 1.
If only the lance protection pipe 11 is installed, the dust generated in the furnace will leak out of the furnace through the lance protection tube 11.In order to prevent this, an airtight chamber 20 with a sealed structure is formed near the nozzle 1', and an airtight An inert gas is introduced into the chamber 20 to maintain the pressure inside the sealed chamber 20 at a higher pressure than the inside of the furnace, and the lance 9 is kept on standby in the high-pressure sealed chamber.

The sealed chamber 20 is installed so as to communicate with the inside of the furnace via the nozzle 1' and the lance protection tube 11, and a cutoff chamber 21 is formed between the lance protection tube 11 and the sealed chamber 20.

The cutoff chamber 21 is provided with a cutoff valve 14 operated by a pivot arm 15, and a connecting portion with the sealed chamber 20 is configured to be openable and closable.

When the lance 9 enters the furnace, the shutoff valve 1 is
4 is opened (retracted to the solid line position in the figure), but at this time, the inert gas pressure in the sealed chamber 20 is higher than the furnace internal pressure, so the dust in the furnace does not enter the sealed chamber 20.

The weight 7 attached to the tip of the wire 6 is the lance 9.
However, when the lance 9 enters the blast furnace and the positioning is completed, the wire 6 is loosened and the weight 7 lands on the charge 4.

Then, the hanging distance of the wire 6 is measured.

During the suspension period of measurement work or during measurement maintenance and inspection work, the lance 9 is completely retreated to the closed chamber 20 and the shutoff valve 14 is closed, and then the inside of the closed chamber 20 is compressed. Dust may penetrate into the cutoff chamber 21 through the lance protection tube 11, and the dust may accumulate in the lance protection tube 11 or adhere to the sealing surface of the cutoff valve 14.

Once such a situation occurs, not only will the subsequent operation of the lance 9 become defective, but also the shutoff state of the shutoff valve 14 will become loose, making it impossible to prevent dust from leaking into the sealed chamber 20, which is extremely dangerous.

Therefore, in order to prevent dust from entering the lance protection tube 11 and cutoff chamber 21 even when the measuring device is in a standby state, there is a method of blowing inert gas into the lance protection tube 11 and cutoff chamber 21, that is, an inert gas purge method. (In the figure, a plurality of inert gas ejection nozzles 22 are arranged on the outer circumferential surface of the cutoff chamber 21, facing approximately the center of the lance protection tube 9.)

However, the diameter of the lance protection tube 11 is generally about 300 mm.
Since the diameter ranges from φ to 500 mmφ, the amount of inert gas consumed becomes enormous, and this is one of the reasons why the running cost of blast furnace operation increases.

The present invention was developed in light of these circumstances, and its purpose is to effectively prevent the intrusion of dust as described above, while at the same time reducing the amount of inert gas consumed. The purpose is to provide an intrusion prevention mechanism.

However, the dust intrusion prevention mechanism of the present invention that was able to achieve such a purpose includes a damper that can be opened and closed at the tip of the lance protection tube, and an inert gas introduced into the lance protection tube and the sealed chamber. The main point is that it is constructed so that it can maintain a higher pressure than the inside of the vertical furnace.

The configuration and effects of the present invention will be explained below in detail based on the drawings, but the examples below are merely representative examples.
Design changes to the shape of the damper, opening/closing mechanism, etc. in accordance with the above-mentioned and below-mentioned purposes are also included in the technical scope of the present invention.

2 is a sectional explanatory view of the dust intrusion prevention mechanism according to the present invention seen from the front, FIG. FIG. 5 is a sectional view taken along the line ■-■ in FIG. 3.

In these figures, the nozzle 1' of the shell 1 that constitutes the blast furnace is shown.
A lance protection tube 11 is connected by a flange so as to protrude into the furnace.

Regarding the construction of the lance protection tube, the upper surface side of the square tube member 11a is cut off leaving the tip portion 11b, and a semicylindrical hood 11C is attached to the cutout portion.

This hood 11C forms a space in which an internal lever, which will be described later, can effectively move and perform a link function.

Further, a damper 30 is mounted at the pivot portion 3 in the tip of the lance protection tube 11 to cut off communication between the inside of the furnace and the inside of the lance protection tube 11.
1 as a fulcrum and is rotatably attached as shown by the arrow in the figure.

In that case, when the damper 30 is in the closed state, the lower side of the damper is attached so that it comes into contact with the lower end edge of the square tube member 11a, and the upper side of the damper comes into contact with the inner edge of the end part 11b, while the damper When 30 is open, damper 3
0 is horizontal, and the lance 9 is installed so that it can enter.

The pivot portion 31 is formed by loosely fitting internal brackets 32 attached to both ends of the damper 30 into protrusions 33 provided on the same circular side wall of the square tube member 11a.

Since the damper 30 is rotatably mounted in this way, there is a slight gap between both end surfaces of the damper 30 and the inner wall surface of the square tube member 11a, and the damper 30 is horizontal. At this time, there is also a slight gap between the outer surface (furnace inner surface) of the damper 30 and the lower surface of the upper surface side tip portion 11b of the square tube member.

Furthermore, a notch 11 is formed in a part of the inner edge of the tip 11b.
b' is formed.

Therefore, when inert gas is blown into the lance protection tube 11, the inert gas is blown out from the gap and notch 11b' to the inside of the furnace immediately in front of the damper, including the outer surface of the damper. A purge condition similar to that in which inert gas is blown without 30 is formed.

Therefore, regardless of whether the damper 30 is opened or closed, dust does not accumulate on the tip edge of the lance protection tube 11 and the outer surface of the damper 30.

The rotation mechanism of the damper 30 has the following configuration.

That is, a connecting member 34 is flange-connected to the lance protection tube 11.

A pivot portion 35 is formed on the upper part of the connecting member 34, and the pivot portion 35 is configured such that a rotating shaft 36 is oriented perpendicular to the axis of the box-shaped hood 34 attached to the upper portion of the connecting member 34. , one end of the rotating shaft 36 is connected to a box-shaped hood 34.
It extends through a seal portion 37 attached to the end face in the direction perpendicular to the axis of a.

Further, an arm rod 38 is fixed to a rotating shaft 36 in the box-shaped hood 34, and a groove-shaped member 39 loosely fitted to an internal lever 43 via a pin 40 is fixed to the other end of the arm rod 38. There is.

Further, a rotating shaft 42 is loosely fitted into small pieces 41 and 41' erected at the upper end of the damper 30.

Then, insert the rotating shaft 42 into the other end of the internal lever 43,
The pin 40 and the internal lever 43 are connected by a link mechanism.

- An arm rod 44 is fixed to the extending end of the front rotating shaft 36, and the arm rod 44 is pivotally connected to the tip of a piston 45a of a driving machine 45.

The driver 45 is attached to the side wall of the cutoff chamber 21.

As the driving machine 45, an air cylinder, a power cylinder, or the like is preferable as a simple and economical model, but of course, this does not mean to exclude other models such as a hydraulic cylinder.

When the rotating shaft 36 and the arm rod 38 rotate as shown by the arrows in the figure due to the operation of the drive unit 45 (the forward and backward movement of the piston 45a), a rotational moment is generated in the upper part of the damper 30 by the link connection by the internal lever 43. Ru.

As a result, the damper 30 rotates as shown by the arrow with the pivot portion 31 as a fulcrum.

Therefore, the damper 30 can be opened and closed in accordance with the entrance of the lance 9 into the furnace and the retreat into the sealed chamber 20.

In addition, since inert gas at a pressure higher than the furnace pressure is blown into the lance protection tube 11 regardless of whether the damper 30 is opened or closed, it is possible to completely prevent dust from accumulating at the tip of the lance protection tube 11 as described above. can.

In this way, the inside of the furnace can be repeatedly measured using the lance 9, and the amount of inert gas required to prevent the ingress of dust can be significantly reduced (by about 95%) compared to the conventional method, which improves blast furnace operation. Running costs can be significantly reduced.

Next, another embodiment will be described based on FIGS. 6 to 8.

Fig. 6 is a cross-sectional explanatory diagram of another example mechanism seen from the front, Fig. 7 is a cross-sectional explanatory diagram of the same plane, and Fig. 8 is an explanatory cross-sectional diagram of the same plane as shown in Fig. 7.
FIG.

The basic difference from the first embodiment is that the damper opening/closing method is horizontally divided, and the damper rotation mechanism is changed in accordance with this method.

That is, in FIGS. 6 to 8, a damper 50.
They are attached so as to be pivotable as shown by arrow A, with each of them as a fulcrum.

In this case, when the dampers 50 and 50' are in a closed state, the front edges of the dampers are in contact with each other, whereas when the dampers 50 and 50' are in an open state, they are parallel to each other, allowing the lance 9 to enter.

The pivot portion 51.51' is a pipe-shaped internal bracket attached to the inner end surface of the dampers 50, 50') 52.52'
is the support 5 provided parallel to the inner side wall of the square tube member 11a.
3.53' with a loose fit.

In the case of this second embodiment as well, since the damper 50.50' is rotatably mounted, the inner end surface of the damper 50.50', the inner wall surface of the rectangular tube member 11a, and the damper 50.5
There is also a slight gap between the lower end surface of the square tube member 11a, the lower inner wall surface of the square tube member 11a, the upper end surface of the damper 50, 50', and the lower surface of the upper end portion 11b of the square tube member. There is.

Furthermore, the outer tip surface 11C' of the hood 11C and the tip portion 11
A hood 54 is provided on each of the holes 11C'' and 11b' to cover the through holes 11C'' and 11b'.

That is, the space below the tip portion 11b and the space within the seventh door 11C are communicated through the through holes 11b' and 110''.

Therefore, when inert gas is blown into the lance protection tube 19, the inert gas flows through the gaps and through holes 11c'' and 1.
1b' to the inside of the furnace including the outer surface of the damper.

Therefore, in this case as well, the same inert gas purge state as in the first embodiment is formed immediately before the damper 50, 50', so that the inner periphery of the tip of the lance protection tube 11 is maintained regardless of whether the damper 50, 50' is opened or closed. And no dust is deposited on the outer surface of the damper 50, 50'.

As for the rotation mechanism of the dampers 50.50', a link mechanism is adopted as in the first embodiment, but two dampers 50.50' are used.
This embodiment differs from the first embodiment in that an adjustment mechanism is added to operate two link mechanisms simultaneously in order to open and close 50' at the same time.

That is, at the upper part of the inner end surface of the damper 50°50',
Arm rods 55 and 55' are respectively attached in a direction substantially orthogonal to 0.50'.

The other ends of the arm rods 55, 55' and the internal levers 57, 57', which are freely supported by the pins 56, 56', form a pair, and a pin 59 is provided upright at the end of the connecting rod 58.
The upper part of the pin 59 is connected to the elongated hole 60 of the link guide 60 fixed to the upper part of the inner peripheral surface of the connecting member 34.
It is possible to move toward the inside of the furnace along line a.

Further, the connecting rod 58 is pivotally supported by one end of a lever 62 which rotates about a pivot 61 as a fulcrum, and the other end of the lever 62 is pivotally connected to a piston 63a of a driving machine 63.

The driver 63 is attached to the side wall of the cutoff chamber 21.

When the piston 63a is actuated, the connecting rod 58 moves forward and backward as shown by the arrows in the figure, and this forward and backward movement generates a rotational moment at the outer end of the damper 50, 50' due to the link connection by the internal lever 57, 57'. to act.

As a result, the damper 50.50' has a pivot point 51.51'
Rotate as shown by the arrow using the fulcrum as the fulcrum.

Therefore, the dampers 50 and 50' can be opened and closed in accordance with the entrance of the lance 9 into the furnace and the withdrawal into the sealed chamber 20.

Also, regardless of whether the damper 50 or 50' is opened or closed, the lance protection tube 11
Since an inert gas having a pressure higher than the furnace internal pressure is blown into the lance protection tube 11, the accumulation of dust at the tip of the lance protection tube 11 can be completely prevented as described above.

The present invention is constructed horizontally as described above, but the key point is that a damper is installed at the tip of the lance protection tube so that it can be opened and closed, and when the lance is retracted, the damper is closed to blow out inert gas from the surrounding gap. At the same time, inert gas is also ejected from above onto the outer surface of the damper, which effectively prevents dust from entering and at the same time significantly reduces inert gas consumption (by approximately 95%). This has made it possible to make a significant contribution to reducing the running costs of blast furnace operations.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a conventional dust intrusion prevention mechanism, Fig. 2 is a cross-sectional explanatory diagram of an embodiment of the mechanism according to the present invention seen from the front, Fig. 3 is a cross-sectional explanatory diagram of the main part of the same plane, and Fig. 4 is a schematic explanatory diagram of a conventional dust intrusion prevention mechanism. The figure is a cross-sectional view taken along the line IV--IV in FIG. 2, FIG. 5 is a cross-sectional view taken along the line ■-V in FIG. 2, FIG. FIG. 8 is a cross-sectional view taken along the line ■t-vtu of FIG. 7.

Claims (1)

[Scope of utility model registration request] A sealed chamber is connected to the lance protection tube protruding through the side wall of the vertical furnace through a cutoff chamber, and a measuring lance is installed inside the sealed chamber, and the lance is connected from the lance protection tube to the vertical furnace. In a dust intrusion prevention mechanism for an in-furnace measuring device in which the lance is moved in and out in the radial direction, a damper is provided at the tip of the lance protection tube so as to be openable and closable, and an inert gas is provided inside the lance protection tube and in the sealed chamber. A dust intrusion prevention mechanism for an in-furnace measuring device characterized by introducing gas and maintaining a high pressure from inside the vertical furnace.