METHOD FOR FIRE DETECTION IN PRODUCTION MACHINES AND PRODUCTION MACHINE

Description

[0001] The present invention relates to a method for fire detection in machines for the production of hollow glass, wherein a manufacturing process on a production machine is controlled by means of a process control and the production machine is permanently monitored by means of fire detection.

[0002] Such a method is already known from KR 101663489. This concerns a production machine equipped with fire detection devices that generate an alarm signal and forward it to a process control system. Furthermore, a fire detection method is already known from EP 0 673 008 B1. This describes a fire monitoring system for a waste bunker, which uses two infrared cameras to create thermal images and, upon detecting a threshold being exceeded, transmits an alarm signal to a process control system. This system then automatically initiates a fire extinguishing process, for example, using a grabber in the waste bunker.

[0003] Another method is known from JP 2021-045723 A, which also involves processing waste using a conveyor belt. If a fire is detected on a conveyor belt using an infrared camera, the conveyor belts are controlled accordingly and the waste is separated.

[0004] Furthermore, WO 2019 / 224122 A1 describes a fire alarm network with a central control unit and several networked fire detection systems, which include an infrared camera. The articles of EP 2 492 883 A1 and EP 2 984 640 B1 operate similarly.

[0005] It is generally known that, in addition to the potential fire hazard posed by waste containing smoldering embers such as cigarette butts, high temperatures can also occur during industrial manufacturing processes. As is generally the case in the prior art, fires are typically extinguished, which usually seems appropriate. However, depending on the external circumstances of the fire and the production context, immediate fire suppression, especially if it involves shutting down production machinery and its associated supply and discharge systems, can be problematic.

[0006] According to the invention, the production of hollow glass is to be used in the present case.

[0007] In the production process, molten glass first flows from a melting tank into a feeder. A shearing mechanism is located beneath the feeder basin, shearing off individual droplets that form there. These droplets are then directed via a droplet distributor to a preform. In the blow-blow process, a first blowing action forces the glass into the lower part, the opening and preform. A level is formed at the opening, around which the glass forms a mold. By withdrawing the level, a cavity remains in the mold. Compressed air is then introduced into this cavity to inflate the mold until it forms a thin-walled cup that fits snugly against the inner wall of the preform. This cup is then transferred to a finishing mold and further shaped with compressed air into its final form.

[0008] In the alternative press-blow process, the level is first shaped as a kind of stamp by applying pressure, pressed into the preform and the glass is thus pre-shaped into a cup, but the final shaping is again done using compressed air.

[0009] This type of process is particularly prone to fires, as the hot material, especially when in contact with machine oil and grease (used for lubrication on the moving and molded parts of production machines), can easily ignite. The additional use of compressed air in the production process, as well as the use of cooling air to regulate the temperature of the machines, can further intensify such fires.

[0010] The initial problem, however, is that the machine operator must be constantly present and even then is unable to oversee the entire area across multiple levels. They must first recognize a fire and assess it as such, and then take the necessary steps, such as activating the emergency stop. Every system, from the feed and material transport to cooling and lubrication, especially the production machine itself, and finally to the product discharge, has its own emergency stop. A global emergency stop for all related systems is not necessarily available. Therefore, it is not guaranteed that all systems will be safely and completely shut down.

[0011] Another problem is the emergency stop itself, which brings the production machine and conveyor belts to an abrupt halt. This means the production machine is completely surrounded by hot, glowing glass, and the temperature in and around the machine rises sharply due to the cooling system also being switched off. As a result, a small, localized oil fire could quickly spread to other areas. Furthermore, the glowing glass containers in the machine and on the conveyor belt pose a danger to firefighters.

[0012] Against this background, the present invention aims to provide a method for fire detection in industrial production machines, as well as a production machine which automatically creates a safe state even at high production temperatures before the start of an extinguishing process, in order to reduce the risk of a major fire for people and machines.

[0013] This problem is solved by a method for fire detection according to the features of independent claim 1. Meaningful embodiments of such a method can be found in the subsequent dependent claims.

[0014] The invention provides a method for fire detection in industrial production machines for the manufacture of hollow glass, wherein a manufacturing process on a production machine is controlled by means of a process control system and the production machine is continuously monitored by means of fire detection. This method is characterized, according to the invention, in a first step, by the means of fire detection generating an alarm signal and transmitting it to the process control system; in a second step, the process control system stops the material request for the manufacturing process and retains further material in a fireproof containment structure, while the production machine processes or ejects already inserted material and is then stopped; and in a third step, all material-supplying and product-discharge machines are stopped.

[0015] While the production machines are continuously monitored using appropriate means, an alarm signal is generated and forwarded to the process control system in the event of a detected fire. The process control system then takes further measures in a second and third step to restore a safe state. First, the material supply to the entire machine is stopped, preventing any additional material from entering the production machine. In the case of glass manufacturing, this means that the droplet supply is terminated and the droplet distributor is deactivated and swung out. This prevents further molten glass from entering the production machine and heating it further. Glass already in the melting tank and furnace remains contained within a fireproof containment area.

[0016] Furthermore, in a subsequent step, the production machine is emptied. Depending on the production stage the machine is currently in, this can mean either that the material is ejected and removed, or that the machine completes the production run and then ejects the material. In this way, each station is brought to a controlled standstill. Each station continues for two cycles and then stops. Simultaneously, the cooling and lubrication systems can be deactivated, thus eliminating the risk of fire acceleration from cooling air and flammable lubricant.

[0017] Finished products can be discharged properly onto conveyor belts that continue to run initially. Only in a third step are these belts, along with all incoming and outgoing systems, switched off. The system then performs an emergency stop, bringing all control and drive systems in the vicinity of the production machine to a safe halt. In this state, all connected systems are switched off, secured against unintentional restart, and de-energized, allowing fire suppression to begin.

[0018] In a particularly preferred embodiment of the invention, the fire detection means may include at least one infrared camera, which is directed at the production machine or parts thereof and generates a thermal image. If at least one temperature threshold is exceeded, an alarm signal is transmitted to the process control system. The use of such infrared cameras allows for comprehensive monitoring of the production machine area, since the entire field of view of an infrared camera is monitored by it, whereas temperature sensors can only monitor a very specific, limited area. The infrared cameras capture a thermal image in which the heat radiation of a point is encoded by corresponding color. Suitable image recognition methods can determine whether a temperature threshold is exceeded in the image and, if so, trigger an alarm.

[0019] In a more concrete implementation, this can be achieved by dividing the infrared camera's field of view into zones, with each zone assigned its own temperature threshold. This allows for the definition of areas that can reach high temperatures without triggering an alarm, while other zones, at significantly lower temperatures, might indicate a fire and trigger an alarm.

[0020] For reliable operation of infrared cameras, it can be beneficial to equip them with air nozzles near their lenses, creating an air shield to protect the lenses from dirt. This air shield keeps dirt away from the lenses while still allowing the imaging radiation to reach them.

[0021] In addition, purely manual fire alarm devices, such as push buttons, can be provided. If personnel detect a fire at an early stage or if it occurs outside the field of view of all infrared cameras, an alarm signal can also be manually sent to the process control system in this way. A particularly advantageous feature of the push button is the inclusion of an acknowledgement switch, which allows the alarm to be silenced. The measures initiated according to the invention are then terminated. In a specific embodiment, only the manual alarm can be acknowledged in this way.

[0022] Additionally, it may be stipulated that, after the third step, at least one extinguishing device for wetting the surfaces of the production machine with an extinguishing agent is activated in a fourth step. This can be achieved specifically by sprinklers, which can be arranged in the area of ​​the production machine and at other locations with a fire hazard.

[0023] Furthermore, it can be useful if the process control system, in response to the initial step, triggers a visual and / or audible alarm by activating signaling devices. Such an alarm signals to personnel in the vicinity of the production machine that a fire has been detected and that appropriate measures must be taken. The alarm is signaled to personnel via suitable signaling devices, whether audible or visual, or even electronic notifications to smart devices, which can also emit haptic signals. This allows personnel to ensure that both people and machines are brought to a safe state and that the fire can then be extinguished.

[0024] The invention described above will be explained in more detail below using an exemplary embodiment.

[0025] They show Figure 1 shows a production machine for the manufacture of hollow glass in a schematic overview from above, Figure 2 shows an exemplary thermal image from an infrared camera in schematic representation, and Figure 3 shows a flow chart of a process for fire detection on a production machine in a schematic flow diagram.

[0026] Figure 1Figure 1 shows a production machine 1 with supplementary equipment and machinery in a top-down view. This production machine 1 is used for manufacturing hollow glass products, such as glass bottles, glass containers like canning jars, and the like. Production machine 1 is an IS machine, meaning it has individual sections 2 in which products 9, namely glass bottles, are produced in parallel. Since production machine 1 works with molten glass, which has a temperature of approximately 1100 °C after melting and is fed into the processing at this temperature, and also requires lubrication to ensure its function with moving parts, the fire hazard in production machine 1 must be considered significant.For this purpose, several distributed infrared cameras 5 are assigned to production machine 1 as a means of fire detection. These cameras cover the individual sections 2 of production machine 1 and monitor at least the most common sources of fire. The fields of view 6 of the infrared cameras 5 are aligned so that production is monitored, but general overview areas are also covered.

[0027] If a fire breaks out on production machine 1, for example due to an improperly guided glass droplet at the droplet distributor falling off, being fanned by an airflow from the cooling system or by escaping compressed air from the production process, and spreading to other areas, it is detected at an early stage by at least one infrared camera 5, and an alarm signal is transmitted to a process control unit 10. The process control unit 10 is located in the Figure 1The example shown is in the immediate vicinity of production machine 1, but for safety reasons it can be located at a greater distance, as long as reliable data transmission to process control 10 is guaranteed.

[0028] In addition to the automatic detection by the infrared cameras 5, additional push buttons 11 are distributed throughout the field. These allow personnel to signal an alarm, for example, if a fire is spotted by chance at a very early stage, before the detection thresholds of the infrared cameras 5 are reached or if the fire is outside their field of view 6. The push buttons 11 are also equipped with acknowledgement switches, which can be used to acknowledge an accidental mechanical triggering of an alarm and to silence the alarm. A signaling device 12 triggers both a visual alarm via a signal light and an audible alarm via a siren as soon as an alarm is triggered, whether by the infrared cameras 5 or manually via a push button 11.

[0029] Figure 2Figure 1 shows a schematic representation of a thermal image 7 from an infrared camera 5, which is directed into a production area of ​​the production machine 1. Products 9 in the form of glass drops or cups are shown, as well as an area 8 essential for the function of the infrared camera 5. The production area of ​​the products 9 has a high temperature, as the concentration of hot glass is highest there. However, only area 8 is monitored, and a certain threshold value must not be exceeded within it. If this threshold value is exceeded, for example, outside of area 8, in the droplet area and the panning area, this area is outside the monitored area 8, and this is permissible due to production requirements. However, if the threshold value is exceeded within area 8, this deviates from the specifications and triggers an alarm signal from the infrared camera 5 to the process control system 10.

[0030] Figure 3 This illustrates the following process. Initially, the system is in a state of permanent monitoring in the flowchart 14. The question that arises continuously 15 is whether the threshold value in one of the thermal images 7, as in Figure 2 The limit shown is exceeded. As long as this is not the case, monitoring will continue.

[0031] However, if the threshold is exceeded, the first step 16 of the system's response begins. In this first step 16, an alarm signal 17 is transmitted, initially and primarily to the process control 10. In parallel, this can also be done directly to the signal transmitters 12, or alternatively, the alarm signal can be forwarded via the process control.

[0032] The second step, 18, follows almost immediately after the first step, 16. A grace period can be paused to allow for the possibility of switching back from alarm mode to permanent monitoring via an acknowledgement, 4. This is possible at any time, and the acknowledgement, 4, can be performed via the process control, 10, or manually via acknowledgement switches on the pushbuttons, 11.

[0033] In the second step 18, the process control system 10 takes initial measures, which do not include immediately shutting down the machines or even firefighting measures, but are intended to first establish a safe state. To this end, in sub-step 19, the material request at the droplet distributor 3 is stopped, which also includes terminating cooling and lubrication to eliminate the basis for the fire. Furthermore, the processing of material by the production machine 1 is initiated. By continuing to operate for two production cycles, the machine processes the input material and ultimately discharges the remaining products 9 in an orderly manner. These are then transported away by the system's transport means, such as a conveyor belt, and fed towards the cooling line.

[0034] Once the material has reached production machine 1 and has been processed, and any remaining material has been held back, a third step 22 follows. In sub-step 23, the supplying and discharging machines are stopped and de-energized. This ensures that extinguishing agents such as water can now be used without creating hazards from electrical voltage. After feedback to the process control 10, a fourth step 24 can follow, in which extinguishing devices 13, such as sprinklers, are activated and the fire is fought.

[0035] The above describes a method for fire detection in industrial production machines, as well as a production machine which, even at high production temperatures, automatically creates a safe state before the start of an extinguishing process in order to reduce the risk of a major fire for people and machines. REFERENCE MARK LIST

[0036] 1 Production machine 2 Section 3 Drop distributor 4 Acknowledgement 5 Infrared camera 6 Field of view 7 Thermal image 8 Area 9 Product 10 Process control 11 Push button 12 Signal transmitter 13 Extinguishing device 14 Monitoring 15 Threshold exceeded? 16 First step 17 Transmission of alarm signal 18 Second step 19 End of material request 20 Processing of material 21 Ejection of material and products 22 Third step 23 Machine stop 24 Fourth step

Claims

1. Method for detecting fires in machines for producing hollow glass, a production process on a production machine (1) being controlled by means of a process controller (10) and the production machine (1) being permanently monitored by means for detecting fires, characterized in that in a first step (16) the means for detecting fires generate an alarm signal and transmit it to the process controller (10), in a second step (18) the process controller (10) terminates the request for material for the production process and further material is retained in a fireproof support, while the production machine (1) processes or ejects material already inserted and is then stopped, and in a third step (22) all machines supplying material and discharging products (9) are stopped.

2. Method according to claim 1, characterized in that the means for detecting fires comprise at least one infrared camera (5) which is aimed at the production machine (1) or at parts thereof and generates a thermal image (7), an alarm signal being transmitted to the process controller (10) in the event of at least one thermal threshold being exceeded.

3. Method according to claim 2, characterized in that a field of view (6) of the infrared camera (5) is divided into regions (8) and one or more regions (8) are assigned their own heat threshold value.

4. Method according to any of claims 2 or 3, characterized in that the infrared cameras (5) are assigned air nozzles in the region of their camera lenses, which air nozzles create an air shield to protect the camera lenses from heat.

5. Method according to any of the preceding claims, characterized in that after the third step (22), in a fourth step (24) at least one extinguishing device (13) is switched on to wet the surfaces of the production machine (1) with an extinguishing agent.

6. Method according to any of the preceding claims, characterized in that the process controller (10) triggers a visual and / or an acoustic alarm by actuating signaling transmitters (12) in response to the first step (16).

7. Method according to any of the preceding claims, characterized in that the process controller (10) deactivates the cooling and / or lubrication of the production machine (1) in the second step (18).