INDUSTRIAL PLANT HAVING AN AREA RELEVANT TO SAFETY

INSTALLATION INDUSTRIELLE AVEC ZONE DE SECURITE

English Abstract

The invention relates to an industrial plant (1) for producing or processing liquid, red-hot or hot metal (2, 6), particularly in a blast furnace installation or in a rolling mill, wherein a safety-relevant area (B1, B2) is formed in the direct vicinity of the liquid or red-hot metal and the presence of a person is at least periodically not allowed. A detector unit (10, 12, 14, 16A, 16B) is provided for the surveillance of said area, detecting electromagnetic radiation emitted by a present person or identifying the absence of electromagnetic radiation blocked by a present person. Furthermore, the invention provides for an evaluation unit (22) which is able to detect the presence of a person from the output data of the detector unit (10, 12, 14, 16A, 16B), and for a control unit (24) which is connected to the evaluation unit (22). If a person is present in the safety-relevant area (B1), the control unit automatically initiates an action acting against the presence of the person. By forming a plurality of safety-relevant areas (B1, B2, B3) having different danger levels, gentle stopping of the industrial plant (1) is made possible.

French Abstract

Selon l'invention, dans une installation industrielle (1) de production ou transformation de métal liquide, chauffé au rouge ou brûlant (2, 6), en particulier dans une installation de haut fourneau ou dans un laminoir, une zone de sécurité (B1, B2), dans laquelle la présence d'une personne est interdite au moins par moments, est formée au voisinage immédiat du métal liquide ou chauffé au rouge. Pour surveiller cette zone, il est prévu un module détecteur (10, 12, 14, 16A, 16B) qui détecte le rayonnement électromagnétique émis par une personne présente ou l'absence d'un rayonnement électromagnétique masqué par une personne présente. Il est prévu en outre un module de traitement (22) qui détecte la présence d'une personne à partir des données de sortie du module détecteur (10, 12, 14, 16A, 16B), ainsi qu'un module de contrôle (24) relié au module de traitement (22) qui, en cas de présence d'une personne dans la zone de sécurité (B1), déclenche automatiquement une action dirigée contre la présence de la personne. La définition de plusieurs zones de sécurité (B1, B2, B3) correspondant à des niveaux de danger différents permet un arrêt en douceur de l'installation industrielle (1).

Claims

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Newly worded patent Claims
1. An industrial plant (1) for producing or processing liquid
or incandescent metal (2, 6), particularly a blast furnace
installation or rolling mill in which a safety-relevant
area (B1), in which the presence of a person is not
permitted at least temporarily, is formed in the direct
environment of the liquid or incandescent metal (2),
characterized by a surveillance device for the safety-
relevant area, comprising:
a) a detector unit (10, 12, 14, 16A, 16B) which detects
electromagnetic radiation emanating from a present
person or the absence of electromagnetic radiation
blocked out by a present person, wherein the detector
unit (10, 12, 14, 16A, 16B) is based on a combination
of at least two of the following detector types:
- a motion detector (14),
- a light barrier (16A, 16B),
- a video camera (10) or a CCD camera,
- a thermal camera,
- a combination (12) of light transmitter and
semiconductor matrix sensor, particularly in CMOS
technology,
b) an evaluating unit (22) which detects from output data
of the detector unit (10, 12, 14, 16A, 16B) the
presence of a person, and
c) a control unit (24) connected to the evaluating unit
(22), which, when a person is present in the safety-
relevant area (B1), automatically initiates an action
acting against the presence of the person, and
d) a plant control device (30) which is connected to the
control unit (24) in such a manner that when an
endangered person is detected, the plant control device
(30) can automatically carry out an intervention in the

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plant operation which reduces the hazard, particularly in
real time.

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2. The industrial plant (1) as claimed in claim 1,
characterized in that the detector unit (10, 12, 14, 16A,
16B) is based on at least one and preferably on a
combination of several of the following detector
principles:
- 1-D sensor or line scan, particularly light barrier
(16A, 16B),
- 2-D sensor or area scan, particularly light curtain or
2D camera,
- 3-D sensor, particularly comprising a light transmitter,
a semiconductor matrix sensor with one photodiode and
one capacitor per pixel for integrating the reflected
transmitter light and a delay determining unit.
3. The industrial plant (1) as claimed in claim 1 or 2,
characterized in that the detector unit (10, 12) generates
an image from the safety-relevant area (B1) and that the
evaluating unit (22) carries out image processing.
4. The industrial plant (1) as claimed in one of claims 1 to
3, characterized in that the image processing carries out
object or pattern recognition, preferably on the basis of
a neural network, so that a person can be distinguished
from a non-human object.
5. The industrial plant (1) as claimed in one of claims 1 to
4, characterized in that there are no protective grids or
fences or that there are fewer protective grids or fences
for securing the safety-relevant area (B1) than would be
necessary for ensuring adequate or prescribed safety
without surveillance device.
6. The industrial plant (1) as claimed in one of claims 1 to
5, characterized in that at least one further safety-
relevant area (B2, B3) is formed which differs or differ
in its/their risk potential

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from the first-mentioned safety-relevant area (B1) and
that the further safety-relevant area or areas (B2, B3)
can be monitored separately for the presence of a person
by the surveillance device.
7. The industrial plant (1) as claimed in claim 6,
characterized in that at least one of the safety-relevant
areas (B2) has a danger level of between "maximum hazard"
and "no hazard".
8. The industrial plant (1) as claimed in claim 7,
characterized in that the intervention can be carried out
with its intensity depending on the risk potential of the
safety-relevant area (B1, B2, B3) in which the forbidden
person has been detected.
9. The industrial plant (1) as claimed in one of claims 1 to
8, characterized in that the intervention, in the case of
a rolling mill, includes a reduction of the rate of
rolling or of throughput and/or a stopping of the mill
train (5).
10. The industrial plant (1) as claimed in one of claims 1 to
8, characterized in that the intervention includes in the
case of a steel mill or blast furnace a delay and/or an
interruption of an opening of the furnace.
11. The industrial plant (1) as claimed in one of claims 1 to
10, characterized by an input device (40) for establishing
a locking area (V) by the operating personnel of a control
room (20).

Description

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Description
Industrial plant having an area relevant to safety
The invention relates to an industrial plant for producing or
processing liquid, incandescent or hot metal, particularly a
blast furnace installation or a rolling mill in which a safety-
relevant area, in which the presence of a person is not
permitted at least temporarily, is formed in the direct
environment of the liquid or incandescent metal.
Devices for the surveillance of spatial areas are known, e.g.
from DE 101 63 534 Al, DE 102 21 578 Al and DE 10 2004 047022 Al.
In this context, sensors are used which provide three-dimensional
information about the monitored area. The principle of the 3D
CMOS sensor is thus based on the fact that a laser and an
electronic lock are exactly synchronized. The lock opens exactly
with the emission of the laser pulse. The extremely short light
pulse illuminates an obstacle - if present - and the reflected
light pulse impinges on the 3D CMOS image converter. The sensor
registers the propagation times which are evaluated as a measure
of the distance and the shape of the obstacle. A light-emitting
diode or a laser can be used as transmitter. One pixel of the
CMOS sensor can in each case comprise one photodiode and an
associated pixel capacitor which is discharged by illumination of
the photodiode when the time window is open.
Modern industrial plants must be planned and operated in such a
manner that the risk to persons is reduced to a minimum. As a
rule, therefore, certain plant sections with high hazard
potential are partitioned off or the access to some areas is
blocked. For this purpose, protective grids and gates can be
provided.
For the partitioning or control of hazardous areas around
machines or in simple industrial plants, so-called

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switching mats or also optical systems, e.g. light barriers are
also known. Like fences with access gates, switching mats have
high constructional complexity. Optical or radiation-based
systems are not taken into consideration under extreme
environmental conditions.
The invention is based on the object of securing and checking a
safety-relevant area in a constructionally simple manner in an
industrial plant having a very strong heat emission, namely in
an industrial plant for producing or processing liquid,
incandescent or hot metal.
According to the invention, this object is achieved with
respect to the industrial plant initially mentioned by a
surveillance device for the safety-relevant area, comprising:
- a detector unit which detects electromagnetic radiation
emanating from a present person or the absence of
electromagnetic radiation blocked out by a present person,
- an evaluating unit which detects from output data of the
detector unit the presence of a person, and
- a control unit connected to the evaluating unit, which, when
a person is present in the safety-relevant area,
automatically initiates an action acting against the presence
of the person.
The inventors have recognized that a radiation-based
surveillance device can guarantee the required safety for a
safety-relevant area also in industrial plants having a high
heat and infrared radiation emission. They are thus breaking
with a technical prejudice. The experts have hitherto not
considered such detector units for blast furnace installations
or rolling mills. Instead, a great amount of effort is expended
with mechanical access barriers now as before. The invention
has the advantage that elaborate mechanical latching devices
such as

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innumerable electrically latched gates in a fence etc. are not
necessary for guaranteeing adequate safeguarding of persons.
Dispensing with or reducing the number of such protective grids
and/or gates also has considerable advantages in the case of
plant maintenance because these fences and gates do not then
impede the access to the plant.
The detector unit is preferably based on at least one of the
following detector types:
- a motion detector,
- a light barrier,
- a video camera or a CCD camera,
- a thermal camera,
- a combination of light transmitter and semiconductor matrix
sensor, particularly in CMOS technology.
The combination of at least two of the aforementioned detector
types in the detector unit is particularly preferred as a
result of which a particularly high safety standard can be
achieved.
It is also of special advantage if detector principles with
different detection dimensionality are used in the detector
unit such as, e.g. a one-dimensional sensor or a line scan,
particularly a light barrier, and/or a two-dimensional sensor
or an area scan, particularly a light curtain or a 2D camera,
and/or a three-dimensional sensor, the latter comprising, in
particular, a light sensor, a semiconductor matrix sensor with
one photodiode per pixel and a capacitor for integrating the
reflected transmitter light and a delay determining unit.
According to a particularly preferred embodiment, the detector
unit is set up for generating an image from the safety-relevant
area and the evaluating unit processes the image. In the image
processing, an object or pattern recognition is preferably
carried out,

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preferably based on a neural network so that a person can be
distinguished from a non-human object.
Apart from the detection of a hazard to persons, this also
makes it possible to detect other unplanned or irregular
movements, e.g. by vehicles or falling parts, in the plant.
According to a preferred development, at least one further
safety-relevant area is formed in the industrial plant which
differs or differ in its/their risk potential from the first-
mentioned safety-relevant area wherein the further safety-
relevant area or areas can be monitored separately for the
presence of a person by the surveillance device. In this
context, at least one of the safety-relevant areas preferably
has a danger level of between "maximum hazard" and "no hazard".
According to another preferred development, the control unit is
connected to a plant control device so that, when an endangered
person is detected, the plant control device can automatically
carry out an intervention in the plant operation which reduces
the hazard, particularly in real time, online and/or without
the interposition of human inputs.
In this context, it is of quite particular advantage if the
intervention can be carried out with its intensity depending on
the risk potential of the safety-relevant area in which the
forbidden person has been detected. This advantageously results
in the possibility for a "gentle" stopping of the plant, e.g.
by initially reducing the rate of rolling or throughput in a
rolling mill when a person is detected in an area of medium
risk potential and only reducing the rate of rolling or
throughput to zero, i.e. stopping the plant,

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if the person penetrates the area of maximum risk potential.
In a steel mill or a blast furnace, the response to a person
penetrating can consist of a delay and/or a complete
interruption of an opening of the furnace.
The industrial plant also preferably has an input device for
establishing a locking area by the operating personnel of a
control room. The operating personnel can thus flexibly define,
for instance within an area of medium risk potential, a
section, the so-called locking area which temporarily has a
higher or the maximum risk level, for instance because a
machine with increased risk potential is temporarily stored in
this area.
An exemplary embodiment of an industrial plant according to the
invention will be explained in greater detail with reference to
the drawing in the text which follows. The single figure shows
as the industrial plant 1 a continuous-casting plant with hot
rolling mill in a greatly diagrammatic form. The invention can
also be applied in a cold rolling mill where the steel, e.g.,
is hotter than 100 C.
Liquid metal 2, e.g. iron, is conducted through a funnel mold 3
and deflection rollers from a vertical feed direction to a
horizontal feed direction. In the horizontal, the ribbon 6,
which is still glowing, passes through several rolling stands 5
after it has been heated in an induction furnace 7.
Around the continuous-casting and rolling area of the
industrial plant 1, several safety-relevant areas B1, B2, B3
are formed which are monitored in each case separately by
themselves by a surveillance device. The monitoring has the aim
of finding out which processes occur in the respective area B1,
B2, B3 and, in particular, whether a person has penetrated in

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forbidden manner in the respective area B1, B2, B3, who would
be exposed to an unacceptable hazard

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in this area. The safety-relevant areas comprise a secure area
B3, a less hazardous area B2 and a very hazardous area B1.
The surveillance device, particularly for the safety-relevant
areas B1 and B2, comprises a detector unit having a number of
different detectors. These are a CCD camera or video camera 10
which generates a two-dimensional image (projection) of the
area monitored, furthermore a three-dimensional image sensor
having a combination 12 of a light transmitter and a
semiconductor matrix sensor arranged in the immediate vicinity
of the light transmitter, furthermore a motion detector 14 and
a light barrier 16A, 16B. The motion detector 14 is based, for
example, on the so-called pyroelectric effect. The light
barrier can be operated with visible or invisible light. As the
3-D sensor, for example, a semiconductor matrix sensor in CMOS
technology is used such as is described, for example, in
DE 10 2004 047022 Al, DE 101 63 534 Al or DE 102 21 578 Al.
Due to the interaction of these different detector types and
detector principles, an evaluating unit 22 which is supplied
wirelessly or in wire-connected manner with the output data of
the said detectors, can detect in a particularly reliable
manner the presence of a person in the safety-relevant area B1
or B2 and distinguish him for example from artifacts generated
from the continuous-casting or rolling area due to interference
radiation. To further secure the person detection process, an
object and pattern recognition of the image generated by the
detector unit also takes place in the evaluating unit 22 by
means of a neural network.
The different safety-relevant areas B1, B2 can be separately
monitored as images in that there is a separate camera or a
separate matrix detector for each area, i.e. that the different

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areas Bl, B2 are defined and specified by the respective
acquisition cone of the associated detectors. As an
alternative, the areas Bl, B2 can be monitored jointly by a
common detector, preferably a 3-D sensor, wherein the
distinction whether there is an unwanted person in the area Bl
or in the area B2 can then be carried out as an evaluation by
means of position data which are supplied by the detector.
In a control unit 24 functionally following the evaluating unit
22, for the case where an unwanted person is detected in a
safety-endangered area B1 or B2, an action acting against the
presence of this person is initiated. This can consist in that
the person is first warned, e.g. for a short time, by a light
or tone signal, e.g. by means of a loudspeaker 26. At a higher
escalation level, the control unit 24 acts directly
functionally on the plant control device 30 which, together
with the evaluating unit 22 and the control unit 24, is
accommodated in a control room 20 of the industrial plant 1. In
the case where the person, after a short audible warning time,
is still located in the hazardous area Bl or B2, the mill train
is stopped or the rate of throughput, respectively, is
reduced. This is done without requiring an intervention by the
operating personnel.
In the case where the safety-relevant areas Bl, B2 are
monitored by a 3-D sensor, in particular, it is of special
advantage that the operating personnel in the control room 20
can establish via an input device 40 a locking area V which is
temporarily graded as having an increased risk potential. The
locking area V shown can thus be temporarily graded in the risk
potential of the area Bl, for example, i.e. if a person enters
the locking area V, an action of the highest escalation level
is immediately triggered, e.g. the immediate stopping of the
rolling mill.

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According to one variant, a thermal camera is used as camera,
which results in the advantage that it is not only persons in
unwanted areas which can be identified but also other unusual
temperature variations can be detected in the industrial plant,
for instance if liquid metal emerges at an unwanted location or
hot iron parts have fallen down.

Representative Drawing