JP3260540B2 - Surveillance camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance camera for monitoring the interior of a closed space or the like separated from a wall through a window provided on the wall, and particularly relates to a method for removing pig iron from iron ore. The present invention relates to a monitoring camera for monitoring the particle size, distribution, gas flow status, and the like of a raw material at a furnace outlet of a blast furnace to be produced.

[0002]

2. Description of the Related Art A furnace port monitoring camera for monitoring the particle size and distribution of raw materials in a furnace port of a blast furnace for producing pig iron from iron ore, the state of gas flow, and the like is known.

[0003] Generally, a blast furnace for producing pig iron from iron ore is provided with a constricted pool at the bottom and a high cylindrical shape at the top, and iron ore charged together with coke from a furnace port at the top. Is lowered and melted by the action of the high-temperature reducing gas generated in the lower pool in the furnace while being lowered in the furnace, and is separated into slag and pig iron. In the blast furnace having the above-described configuration, iron ore as raw material and coke serving as fuel form a mortar-shaped hole having a lowest center portion in the furnace opening,
Charging is performed according to a predetermined stacking pattern designed so that a material having a predetermined particle size is arranged at a predetermined position in a furnace opening. As the stacking pattern, a pattern suitable for producing pig iron is selected according to the situation of each blast furnace.

In order to form the stacked pattern,
The iron ore and coke are charged into the furnace opening by a charging device such as a swivelable chute or a bell that moves up and down provided above the furnace opening according to a predetermined charging pattern. However, the charged iron ore and coke are rolling toward the center of the mortar.
In addition, it is difficult to maintain the stacking pattern as designed because a blowing phenomenon occurs in which the reducing gas blows upward from around the iron ore and coke.

[0005] The furnace port monitoring camera is provided to monitor the particle size and distribution of iron ore and coke in the furnace port and the blow-through of the reducing gas. According to the furnace port monitoring camera, when an undesired change occurs in the particle size and distribution state of iron ore and coke in the furnace port, or when a blow-through of the reducing gas occurs at an unexpected position, the position is determined. Since the iron ore and coke can be accurately charged from the charging device at the position, the stacking pattern can be easily maintained.

As shown in FIG. 3, a conventional furnace port monitoring camera 31 monitors the state of the stacking pattern 5 in the furnace port through a window 4 provided on the peripheral wall 3 of the furnace port 2 of the blast furnace. And comprises a lens system 32 and an image sensor 33 provided behind the window 4. However, the furnace port monitoring camera 31 shown in FIG. 3 must be provided at a considerable distance behind the window portion 4 in order to obtain a field of view as wide as possible. A sufficient range of 5 could not be included in the field of view. Moreover, in the furnace port monitoring camera 31, if the window portion 4 is made large so that the optical path of the lens system 32 can be secured, the raw material iron ore and the coke dust which are rolled up in the gas flow of the reducing gas in the furnace port 2 are formed. Therefore, there is also a problem that the window 4 is easily contaminated and it is difficult to constantly monitor the inside of the furnace port 2.

In order to solve the above-mentioned inconvenience, the present applicant has already applied for a patent for the furnace port monitoring camera 41 shown in FIG. 4 (see Japanese Patent Application No. 3-315622). The furnace port monitoring camera 41 described in the above specification monitors the state of the stacking pattern 5 in the furnace port 2 through a window 4 formed of a small hole provided on the peripheral wall 3 of the furnace port 2. , A short-focus wide-angle lens system 42 provided behind the window 4 and the image sensor 4
3 The window 4 is provided at a focal position on the optical axis of the wide-angle lens system 42.

According to the furnace port monitoring camera 41, the wide-angle lens system 42 can cover almost the entire range of the stacked pattern 5 in the field of view. Also, wide-angle lens system 4
Since the lens 2 has a short focal length, the lens 2 can be provided close to the rear of the window 4, and the entire apparatus can be reduced in size.

Further, since the window portion 4 is provided at a focal position where light passing through the synthetic lens constituted by the wide-angle lens system 42 converges, the light path of the wide-angle lens system 42 can be sufficiently reduced even with a small hole. The small holes make it easy to maintain and manage the dirt in the furnace port 2 and constantly monitor the inside of the furnace port 2.

The furnace port monitoring camera 41 can also illuminate its field of view by illuminating means 44 provided above the peripheral wall 3.

However, in order to analyze the charging pattern of the iron ore and coke in order to maintain the stacking pattern 5 in an appropriate state and make it even more preferable, it is not enough to monitor the stacking pattern 5 in a wide range. However, it is desired to grasp in detail the particle size and distribution state of iron ore and coke, and the state of blow-through of the reducing gas.

In order to grasp in detail the particle size and distribution state of iron ore and coke, and the state of blow-through of the reducing gas by the furnace port monitoring camera 41, the camera is mounted on the same optical axis as the wide-angle lens system 42. It is conceivable to provide a zoom lens system 45 that operates integrally with the wide-angle lens system 42 as shown by a virtual line in FIG. 4 to enlarge the image obtained by the wide-angle lens system 42.

However, since the zoom lens system 45 has the same optical axis as the wide-angle lens system 42, the zoom lens system 45 can only expand and contract around the optical axis. Cannot be expanded around That is, even if the zoom lens system 45 is provided in the furnace port monitoring camera 41, the optical axis of the small hole 4, the wide-angle lens system 42, and the zoom lens system 45 match, so that the wide-angle lens system 42 can be used. There is a disadvantage that the periphery of the visual field of the image cannot be enlarged.

In order to analyze the charging pattern of the iron ore and coke, it is not enough to monitor only the central portion of the stacking pattern 5, and it is not enough to monitor the particle size and distribution of the iron ore and coke and the reducing gas. It is desired to grasp the situation of the stairwell in more detail.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide an improved surveillance camera.

It is another object of the present invention to provide a surveillance camera that can cover a wide range within an optical field of view and can expand and contract around an arbitrary point over the entire range of the optical field of view.

It is another object of the present invention to easily maintain a stacking pattern of iron ore and coke charged in a furnace opening of a blast furnace for producing pig iron from iron ore and to analyze the charging pattern. It is to provide a surveillance camera.

[0018]

In order to achieve the above object, a surveillance camera according to the present invention is a surveillance camera for monitoring a state opposite to a wall surface through a window provided on the wall surface. A first imaging unit having a wide-angle lens system;
A second imaging unit having a zoom lens system for enlarging and reducing the optical image obtained by the wide-angle lens system, wherein the second imaging unit observes an arbitrary portion of the optical image obtained by the wide-angle lens system And a driving means for driving as much as possible.

The wide-angle lens system has a viewing angle of 60 to 80 °.
The zoom lens system has a zoom ratio of 4-1.
Five are used.

The driving means drives the second imaging means such that the new optical axis is directed at an arbitrary angle in an arbitrary direction around the original optical axis, thereby simplifying the apparatus. However, the second imaging means may be driven vertically and horizontally so that the new optical axis is parallel to the original optical axis.

Further, the first imaging means and the second imaging means are constituted by a single imaging means, and a single imaging means has both functions. Alternatively, the first imaging means and the second imaging means may be provided independently.

The surveillance camera of the present invention is also used for monitoring conditions in a firebox such as a boiler and a garbage incinerator, and is particularly provided on a peripheral wall of a furnace opening of a blast furnace for producing pig iron from iron ore. It is characterized in that it is used for observation of the inside of the furnace port through the window provided.

[0023]

According to such means, usually, the entire optical image on the opposite side of the wall surface obtained by the wide-angle lens system by the first imaging means is monitored. Then, in the optical image obtained by the wide-angle lens system, if there is a part to be observed particularly in detail,
The second imaging unit is driven by the driving unit, and its optical axis is directed to the portion. According to the second imaging means, an optical image enlarged by the zoom lens system is obtained, so that the situation of the portion can be grasped in detail.

For example, when monitoring the furnace port of the blast furnace, an optical image of the entire furnace port is obtained by the wide-angle lens system. In the optical image, a portion where the stacking pattern is no longer appropriate or the reducing gas When the portion where the blow-through occurs is observed, the second imaging unit is driven by the driving unit, and the optical axis thereof is directed to the portion. By doing so, an optical image enlarged by the zoom lens system is obtained by the second imaging means, so that the above-described portion can be observed in detail, and the particle size and distribution of iron ore and coke in the furnace port The state of the stacking pattern such as the above and the state of the blow-by of the reducing gas are grasped in detail.

In the surveillance camera according to the present invention, the driving means drives the second imaging means such that the new optical axis is directed at an arbitrary angle in an arbitrary direction around the original optical axis. By doing so, the device is simplified. In addition, the apparatus is downsized by being configured with the first imaging unit, the second imaging unit, and a single imaging unit so that one imaging unit has both functions.

[0026]

Next, a surveillance camera according to the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory sectional view showing an example of a configuration in a case where the monitoring camera of the present invention is used for monitoring a furnace port of a blast furnace, and FIG. 2 is an enlarged view of a main part of FIG.

As shown in FIG. 1, a furnace port monitoring camera 1 according to the present embodiment includes a furnace port 2 inside a furnace port 2 through a window 4 formed of a small hole provided on a peripheral wall 3 of the furnace port 2 of the blast furnace. Stacked pattern 5
The wide-angle lens system 8 is fixed to an outer tube 7 fitted to a mounting portion 6 provided around the window 4 on the peripheral wall 3. That is, the wide-angle lens system 8 is fixed to the peripheral wall 3 as a pair. Also, a wide-angle lens system 8
The lens barrel tube mounting portion 9 is accommodated in an outer tube tube 7 to which is fixed. As shown in FIG. 2, an imaging device 11 having a zoom lens system 10 is provided in the lens barrel tube mounting portion 9. In the furnace port monitoring camera 1, the zoom lens system 10 is provided so as to have the same optical axis as the wide-angle lens system 8 in a normal state. Function and zoom lens system 10
It also serves as a function for. FIG.
As shown, a close-up lens 24 is provided in front of the zoom lens system 10. The lens barrel mounting part 9 includes
A driving device 12 is provided for driving the image pickup device 11 so that any part of the optical image obtained by the wide-angle lens system 8 can be observed.

The furnace port monitoring camera 1 is connected to an image display device 13 and a control device 14, and the control device 14 is connected to a drive device 12. The optical images obtained by the wide-angle lens system 8 and the zoom lens system 10 are converted into electric signals by the image pickup device 11 and displayed on the image display device 13. The driving device 12 can be driven by operating the control device 14 while monitoring the stacking pattern 5 on the screen of the image display device 13.

As shown by the imaginary line in FIG. 2, the driving device 12 is driven to swing with the image sensor 11 as a center of rotation and the lens barrel mounting portion 9 and the base of the lens barrel mounting portion 9 as a fulcrum.
The swing drive is performed in an arbitrary direction around the original optical axis of the zoom lens system 10. As a result, the zoom lens system 10 is driven such that the new optical axis is directed at an arbitrary angle in an arbitrary direction around the original optical axis.

Incidentally, the furnace opening monitoring camera 1 can also illuminate its field of view by an illumination means 15 provided above the peripheral wall 3.

Next, a detailed configuration of the furnace port monitoring camera 1 will be described.

As shown in FIG. 2, a partition 21 is provided in the mounting portion 6 so as to shut off the atmosphere in the furnace port 2 from the inside of the outer tube 8. A seal provided in the center of the partition 21 is provided. The optical paths of the wide-angle lens system 8 and the zoom lens system 10 are secured by the loading glass 21a. In addition, a shielding glass 22 is provided at a tip of the outer tube 7 on the side of the mounting portion 6. In the furnace monitoring camera 1, the window 4 and the partition 2
1 and a low-pressure nitrogen gas between the partition 21 and the shielding glass 22 to prevent the intrusion of the atmosphere in the furnace port 2 and to be wound up by the reducing gas stream. The shielding glasses 21a and 22 are prevented from being stained by dust of the raw material iron ore and coke. Further, a shut-off cylinder 23 for opening and closing the window portion 4 is slidably provided between the mounting portion 6 and the peripheral wall 3, and when there is a possibility that the dusting may stain the shielding glasses 21a and 22, the window is opened. The part 4 can be closed.

Behind the shielding glass 22, the wide-angle lens system 8 is fixed. The wide-angle lens system 8 includes a wide-angle lens 8a having a diameter of 150 mm and a focal length of 9 cm, and a lens 8b having a diameter of 150 mm and a focal length of 9 cm.
It is fixed to the outer tube 8 at intervals of m. The wide-angle lens system 8 composed of the wide-angle lens 8a and the lens 8b has a focal length of about 4.5 cm. The window 4 is positioned 9 cm forward which is the focal length of the wide-angle lens 8 a, and the viewing angle of the wide-angle lens system 8 that views the inside of the furnace port 2 through the window 4 is about 80 °. .

A zoom lens system 10 is provided 28 cm behind the wide-angle lens system 8.
The imaging element 11 is provided at the image forming point. The zoom lens system 10 has a variable focal length of 0.8 to 8 cm, a zoom ratio of 8, a maximum viewing angle (angle of view) of 43.6 °, a minimum viewing angle of 4.6 °, and an imaging closest distance of 1.2 m. And a close-up lens 24 for reducing the closest imaging distance from 1.2 m to 18.8 cm. According to the close-up lens 24, the distance required for the zoom lens system 10 can be reduced. Function as a system,
The entire device can be reduced in size.

Next, the operation of the furnace opening monitoring camera 1 will be described.

In the furnace port monitoring camera 1, the wide-angle lens system 8
The range of about 80 ° which views the inside of the furnace port 2 from the window part 4 becomes a field of view, and an object (about 16.8 m) located 10 m in the front furnace port 2 of the wide-angle lens system 8 is about 9 cm behind the wide-angle lens system 8. A real image of an inverted 15.1 cm image is formed at the position. The field of view corresponds to a range of a semicircle or more inside the furnace port 2.

In the furnace port monitoring camera 1, usually, the zoom lens system 10 has the same optical axis as the wide-angle lens system 8, and the viewing angle is 43.6 °. In this state, the entire 15.1 cm inverted real image is displayed on the entire screen of the image display device 13.

Next, the viewing angle of the zoom lens system 10 is set to 4.
If it is 6 °, the zoom ratio at this time is 10, so
1.51 cm corresponding to about 1/10 of the 15.1 cm inverted real image is enlarged and displayed on the screen of the image display device 13. This corresponds to a field of view of about 8 ° in which the inside of the furnace port 2 is viewed from the window 4.

When the viewing angle of the zoom lens system 10 is 4.6 ° as described above, the range of the diameter of 16.8 m of the surface of the iron ore or coke charged in the furnace port 2 is 10 °.
When observed with the furnace opening monitoring camera 1 m apart, a range of 1.68 m in diameter, which is 1/10 of the above range, is displayed on the image display device 1.
3 is displayed on the entire screen. At this time, the image display device 1
If the number of display elements of 3 is 510, the length displayed per display element is 3.3 mm. Usually, the range in which the human eye can recognize an object on the image display device 13 having the display element is set to two display elements.
An object of about 7 mm can be identified on the screen at a distance of 10 m.

The viewing angle of the zoom lens system 10 is 43.
At 6 °, the length displayed per display element is 33 mm, so the length of the object that can be identified on the screen is 66 mm.

The image enlarged by the zoom lens system 10 is a range centered on the optical axis of the wide-angle lens system 8,
By driving the imaging device 11 together with the lens barrel mounting portion 9 by the driving device 12 as described above, the wide-angle lens system 7 allows the user to view the inside of the furnace port 2 from the window portion 4 through an arbitrary range of about 80 °. The portion can be magnified and observed as described above.
The angle at which the image sensor 11 is driven to swing may be any angle as long as the 15.1 cm inverted real image is desired from the image sensor 11.
In the present embodiment, since the distance between the image sensor 11 and the inverted real image is about 21 cm, it is about 39.4 °. In this manner, the image sensor 11 is driven such that its optical axis is directed in an arbitrary direction within the cone that desires the 15.1 cm inverted real image from the image sensor 11.

When the image pickup device 11 is driven by the driving device 12, two detectors are attached to the lens barrel attaching portion 9, and
This is performed by taking the x-axis as the optical axis and the y-axis in the vertical plane, and taking out two signals as displacements with their angles from their reference points as angles or radial distances from the optical axis in a cylindrical coordinate system. The driving device 12 controls the imaging device 1.
1 is driven, the furnace port 2 is displayed on the screen of the image display device 13.
Because I do not know which part of
The signal taken from the detector is converted into an expression generally used in blast furnace operation, for example, an angle shown in the circumferential direction with the hot air main pipe as the reference point O, a distance from the furnace center, etc. May be superimposed on the data.

The converted values are the height of the image sensor 11 from the height reference point of the blast furnace, the height of the reference surface position (struck line) of the charge, and the angle of repose of the charge based on the mounting angle. , And is calculated from the two signals based on the furnace radius.
The inverted real image at this time is an image obtained by the wide-angle lens system 8, and has optical aberration. The optical aberration is small in the central part of the real image, but reaches 20% in the peripheral part. Therefore, the in-furnace position and the image position are calculated by correcting the optical aberration.

In the above embodiment, the driving device 12 drives the imaging device 11 so that the new optical axis of the zoom lens system 10 is directed at an arbitrary angle in an arbitrary direction of the original optical axis. An orthogonal coordinate axis intersecting the optical axis in a plane perpendicular to the optical axis is set, and the image sensor 11 is moved to an arbitrary point on the coordinate axis while keeping the new optical axis of the zoom lens system 10 parallel to the original optical axis. May be driven vertically and horizontally.

In the present embodiment, a 10 × zoom lens of 0.8 to 8 cm was used, and its performance was fully used.
Although the focal length of the close-up lens is short and the distortion is large, the magnification of the zoom lens may be about 6 times using a 33.3 cm lens. In any case, according to the present invention, the first imaging unit having a large-diameter wide-angle lens system
A large inverted optical image is obtained, the maximum magnification of the object is determined in combination with the second imaging means having a high-magnification zoom lens system, and the close-up lens is a second optical system having an inverted optical image and a zoom lens system. The effective magnification is determined from the physical dimensions allowed by the imaging means.

The camera 1 for monitoring the furnace port of this embodiment observes an arbitrary portion of the optical image obtained by the wide-angle lens system 8 with the zoom lens system 10 in addition to the purpose of monitoring the inside of the furnace port 2. It can be applied to various uses. For example, boiler,
Through the small hole, the inside of firebox such as garbage incinerator, heating furnace
With a combination of the first imaging means having a wide-angle lens system fixed to the apparatus main body and the second imaging means having a zoom lens system, a wide field of view and any point in the entire field of view can be locally enlarged. In addition to the closed space, the abnormal situation in the general landscape can be enlarged by using similar means to make small holes in the wall to widen the field of view and locally expand any point in the entire field of view. Can be monitored.

[0047]

As is apparent from the above description, according to the surveillance camera of the present invention, any part of the optical image obtained by the wide-angle lens system can be enlarged and observed by the zoom lens system. Therefore, the situation on the opposite side of the wall surface can be grasped in detail.

In the surveillance camera according to the present invention, the driving means drives the second imaging means so that the new optical axis is directed at an arbitrary angle in an arbitrary direction around the original optical axis. Or the first imaging unit and the second imaging unit are arranged so that the wide-angle lens system and the zoom lens system have the same optical axis, and one imaging unit has both functions. As a result, the size of the apparatus can be reduced.

The surveillance camera of the present invention is used for monitoring the inside of the furnace port of a blast furnace, and thus, the state of the stacking pattern such as the particle size and distribution of iron ore and coke in the furnace port, and the blow-through of the reducing gas. The situation can be grasped in detail, the stacking pattern can be appropriately maintained, and the charging pattern for charging the iron ore and coke into the furnace port can be easily analyzed.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one configuration example of a surveillance camera according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an explanatory sectional view showing a configuration example of a conventional furnace port monitoring camera.

FIG. 4 is an explanatory sectional view showing another configuration example of a conventional furnace port monitoring camera.

[Explanation of symbols]

1 ... surveillance camera 2 ... opposite side of wall surface 3 ... wall surface
Reference numeral 4 denotes a window, 8 denotes a wide-angle lens system, 10 denotes a zoom lens system, 11 denotes imaging means, and 12 denotes driving means.

Claims (4)

(57) [Claims] 1. A surveillance camera for monitoring a state on the opposite side of a wall surface through a window provided on the wall surface, comprising: a first imaging unit having a wide-angle lens system; A second imaging unit having a zoom lens system for enlarging and reducing the obtained optical image, wherein the second imaging unit is driven so that any part of the optical image obtained by the wide-angle lens system can be observed. A surveillance camera comprising a driving unit. 2. The apparatus according to claim 1, wherein said driving means drives said second imaging means so that its new optical axis is directed at an arbitrary angle in an arbitrary direction around the original optical axis. Item 2. The surveillance camera according to Item 1. 3. A surveillance camera according to claim 1, wherein said first and second imaging means are constituted by a single imaging means, and said single imaging means has both functions. 4. The monitoring camera according to claim 1, wherein the monitoring camera is used for observing the inside of the furnace port through a window provided on a peripheral wall of the furnace port for producing pig iron from iron ore. The surveillance camera according to 1.