Computer-implemented method for optimising the temperature regulation of molten glass along a feed channel of a glass bottle production plant

Abstract

A method (1 ) implemented by a computer for regulating the temperature of molten glass along a feed channel of a plant for the production of glass objects, in particular glass bottles. The method comprises acquiring at least one thermographic image (100, 200) of at least one drop produced by the forming apparatus interposed between said feed channel and the IS type machine of said plant, segmenting said thermographic image (100, 200) into a plurality of sections (i), uniquely associating each of the sections (i) with a portion (y) into which the cross-section of said feed channel is divided, identifying the temperature deviation of each of the sections (i) with respect to a first predetermined ideal temperature value (TM1i) specific for each section (i), obtaining a first temperature deviation map (ST1), activating the temperature variation means distributed along the feed channel by adjusting the temperature of the molten glass flowing through each of the portions (y) according to the deviations defined by the first temperature deviation map (ST1).

Description

[0001] COMPUTER-IMPLEMENTED METHOD FOR OPTIMISING THE TEMPERATURE REGULATION OF MOLTEN GLASS ALONG A FEED CHANNEL OF A GLASS BOTTLE PRODUCTION PLANT.

[0002] DESCRIPTION

[0003] The present invention concerns a computer-implemented method for optimising the temperature regulation of molten glass flowing along a feed channel of a plant for the production of glass bottles or other glass objects.

[0004] The invention also relates to a plant for the production of glass bottles or other glass objects, with which the above method is implemented.

[0005] It is well known that in plants for the production of bottles or other glass containers or objects from a molten glass drop, the feed channel is that part of the plant that brings the molten glass from the melting furnace to the dropforming apparatus that will subsequently feed an IS type machine.

[0006] The temperature in the part of the feed channel closest to the furnace is usually around 1 ,200°C, while in the vicinity of said forming apparatus, the temperature is around 1 ,100°C. It is therefore necessary, along the path of the feed channel, to disperse the excess heat while trying to keep the glass at a temperature as uniform as possible. In fact, heat dissipation will be greatest near the edges of the feed channel and lowest towards its centre. A cooling / heating strategy must therefore be implemented in different portions of the feed channel to ensure both the final balance of dispersion before the forming apparatus, and adequate heating in the peripheral zones so as not to generate inhomogeneity in the temperature distribution in the glass, resulting in a density and viscosity gradient that would lead to defects in the finished product.

[0007] Therefore, the aim of the temperature management as a whole is to make the glass reach the drop-forming apparatus at the desired temperature and to ensure that it is as uniform as possible over the entire mass of glass to be processed.

[0008] To ensure this, according to the prior art, temperature variation means are installed along the feed channel, in particular heating elements (e.g. burners) to raise the temperature in the portions of the feed channel where the glass cools faster, and cooling elements (e.g. indirect ventilation and cooling chimneys) for the portions of the feed channel where heat dispersion is less efficient, in particular the lower part of the feed channel and the upper central area.

[0009] Figure 1 illustrates a channel C for conditioning molten glass, designed to regulate the temperature and quality of the glass prior to forming. The glass moves along the channel C under the influence of gravity and the inclination of the same channel C, allowing a continuous and controlled flow. After being conditioned the molten glass exits the channel C from the right end, ready for forming.

[0010] In particular, as can be seen in Figure 1 , the molten glass enters the channel C from the left, as indicated by the arrow.

[0011] Along the channel C there is a heating system R, in particular burners that provide heat to maintain the desired temperature of the molten glass.

[0012] In addition, along the channel C there is a cooling system by means of air flows FA configured to gradually lower the temperature of the glass, ensuring optimal viscosity for processing.

[0013] As mentioned, the feed channel is generally divided into several portions and each of them is responsible for dispersing a certain temperature gradient. The trend of the temperature gradient along the various portions of the feed channel is strategic in ensuring ideal conditions for glass processing in the forming machine. The desired temperature gradient between the various portions is known as the “ideal curve”.

[0014] According to the prior art, in order to be able to implement such a strategy to manage the temperature of the molten glass in the feed channel, it is provided to install a plurality of thermocouples along the feed channel itself, which are capable of measuring the temperatures of the molten glass in various portions of the feed channel itself.

[0015] In particular, since the temperatures can be different along both the horizontal and vertical axis of the glass in the feed channel, it is envisaged to install, in the most complete versions of the plants of the prior art, nine thermocouples T, each of which is arranged in one of the nine portions P, also known as equalisation zones, into which the cross-section of the feed channel is divided according to a cross-sectional plane orthogonal to the longitudinal extension axis of said feed channel. More specifically, these nine portions P are identified according to a 3x3 matrix pattern in said cross-section, as exemplified in Figure 2.

[0016] However, although the implementation of such a strategy makes it possible to ensure greater temperature uniformity of the molten glass within the feed channel, it is disadvantageously not a foregone conclusion that once the glass enters the forming apparatus and is manipulated by it to form the drop or the drops, such glass maintains its temperature uniformity over the entire volume and the entire length of the drop.

[0017] In other words, controlling the temperature of the molten glass within the feed channel does not guarantee that the drops obtained through the forming apparatus also exhibit the same temperature uniformity.

[0018] The present invention intends to overcome the drawbacks of the prior art.

[0019] In particular, it is an object of the invention to define a method of optimising the temperature regulation of the molten glass along the feed channel of a plant for the production of glass bottles or other glass objects, enabling the temperature uniformity of the drops formed by the forming apparatus of said plant to be optimised.

[0020] Therefore, it is an object of the invention to define a method of optimising the temperature regulation of the molten glass along the feed channel that will ensure greater uniformity of the chemical-physical characteristics of the drops formed by the forming apparatus and thus avoid defects in the finished product. A further object of the invention is to more precisely control the activation of the temperature variation means along the feed channel.

[0021] The above-mentioned task and aims are achieved by a method implemented by a computer according to claim 1 .

[0022] Further features of the method according to claim 1 are described in the dependent claims.

[0023] Also part of the invention is the plant for the production of bottles or other glass objects with which the above method is implemented, according to claim 14.

[0024] The task and the aforesaid objects, together with the advantages that will be mentioned hereinafter, are highlighted by the description of an embodiment of the invention, which is given by way of example, with reference to the accompanying drawings, where:

[0025] - Figure 1 schematically shows a feed channel of a glass bottle production plant, comprising means for varying the temperature of the molten glass flowing along said feed channel;

[0026] - Figure 2 schematically shows the arrangement of thermocouples within a feed channel;

[0027] - Figure 3 shows a flow chart of the method for regulating the temperature of molten glass along a feed channel;

[0028] - Figure 4 schematically shows two thermographic images of the same drop, acquired simultaneously from two distinct spatial positions;

[0029] - Figure 5 schematically shows the two thermographic images of Figure 4 after the segmentation operation;

[0030] - Figure 6 schematically shows a glass bottle production plant of the invention configured to perform the method of the invention.

[0031] The method of the invention, implemented by means of a computer, for regulating the temperature of molten glass along a feed channel of a glass bottle production plant is schematically shown in Figure 3, where it is indicated overall by number 1.

[0032] According to the preferred embodiment of the invention, said method 1 first of all provides for the simultaneous acquisition of two thermographic images 100 and 200 from two distinct spatial positions of the same drop G formed by the forming apparatus of said plant.

[0033] It cannot be ruled out, however, that according to a variant embodiment of the invention it is provided to acquire only one thermographic image of each drop, or it is provided to simultaneously acquire more than two thermographic images of the same drop, still in spatially distinct positions.

[0034] Furthermore, it cannot be ruled out that, in the event that the forming apparatus forms several drops at the same time, each of these thermographic images relates to the plurality of said drops.

[0035] Returning to the preferred embodiment of the invention, once said thermographic images 100 and 200 have been acquired for each drop G, the method involves segmenting each of the two thermographic images into an equal number of sections i, preferably into nine sections i, where 0 < i <= 9, distributed according to a 3x3 matrix, as depicted in Figure 5.

[0036] Next, the method involves linearly combining one or more of the sections i of the first image 100 with one or more of the sections i of the second image 200.

[0037] Preferably, but not necessarily, the method of the invention involves uniquely associating each of the sections i of the first image 100 with a corresponding section i of the second image 200.

[0038] According to the invention, once such a linear combination has been performed, the method 1 provides to identify a temperature deviation value for each of the aforementioned linear combinations with respect to a predetermined ideal temperature value in order to determine a first temperature deviation map STi. In particular, according to the aforementioned preferred embodiment of the invention, which provides for uniquely associating each of the sections i of the first image 100 with one of the sections i of the second image 200, said identification step provides for calculating the mean temperature value Msi of each pair of sections i associated with each other, and calculating the temperature deviation of each of these mean temperature values Msi with respect to a first predetermined ideal temperature value TMH relative to each section i, in order to determine the first temperature deviation map STi. In other words, for each section i into which the two images 100 and 200 are divided, it could be provided to predetermine a first predetermined ideal temperature value TMH, distinct from the remaining first predetermined ideal temperature values TMH relating to the other sections i.

[0039] It is not excluded, however, that according to variant embodiments of the invention, the determination of the aforementioned first temperature deviation map STi may be carried out with different logic from that just described.

[0040] It should also be noted that, according to alternative embodiments of the invention involving the acquisition of a single image per drop, in this case the detection of deviations would be performed by considering the deviation of the temperature value of a single section i of the image with respect to the relative first predetermined ideal temperature value TM-IL

[0041] Returning to the preferred embodiment of the invention, each of the first predetermined ideal temperature values TMH is selected equal to the mean of the mean temperature values Msi of the pairs of sections i of the two superimposed images 100 and 200.

[0042] It cannot be ruled out, however, that such predetermined ideal temperature values could be chosen in some other way and, as mentioned above, that each first predetermined ideal temperature value TMH relative to each section i could be chosen different from the first predetermined ideal temperature values TMH relative to the other sections i.

[0043] Furthermore, still according to the preferred embodiment of the invention, the temperature deviation is calculated as a percentage deviation value with a sign, with respect to said first predetermined ideal temperature value TMH.

[0044] This way of defining the deviation, as will be understood shortly, is advantageous in that it allows the temperature deviation of the various sections of the drop to be compared in relative terms with the temperature deviation of the molten glass inside the feed channel. Even in this case, however, according to different embodiments of the invention, this deviation could be calculated as an absolute value with respect to the aforementioned predetermined ideal temperature value.

[0045] According to the preferred embodiment of the invention, thereafter, the method 1 provides for measuring the temperature of the molten glass Meyflowing through the feed channel for each of the portions y into which the cross-section of the feed channel itself is ideally divided, according to a cross-sectional plane orthogonal to the longitudinal extension axis of said feed channel, as depicted in Figure 2. As already indicated for the prior art, this measurement is preferably performed by means of thermocouples, in particular nine thermocouples, each arranged at one of the nine portions y into which this feed channel is ideally divided.

[0046] Again, in accordance with the preferred embodiment of the invention, the method involves identifying the temperature deviation of each of the aforementioned portions y with respect to second predetermined ideal temperature values TM2y, each relative to a specific portion y, resulting in a second temperature deviation map ST2.

[0047] Still preferably, even for the definition of the second temperature deviation map ST2 it is envisaged that all the second predetermined ideal temperature values TM2y be chosen equal to the mean of the temperature values Meymeasured for the aforementioned portions y, and furthermore, that the temperature deviation is defined as a percentage deviation value with a sign, with respect to the second predetermined ideal temperature value TM2y.

[0048] It is not excluded that, according to different embodiments of the invention, the second predetermined ideal temperature values TM2ymay be chosen differently, that each second predetermined ideal temperature value TM2y relative to each portion y may be chosen different from the second predetermined ideal temperature values TM2y relative to the other portions y, and that the deviation is represented as an absolute value with respect to the second predetermined ideal temperature value TM2y.

[0049] In any case, once the second temperature deviation map ST2 has also been defined, the method 1 of the invention includes correlating the first temperature deviation map ST1 with the second temperature deviation map ST2, so as to obtain a closer correspondence between said deviations of the first temperature deviation map ST1 and the deviations of the second temperature deviation map ST2.

[0050] In detail, according to the preferred embodiment of the invention, said correlation consists in applying a transformation to said first temperature deviation map ST1, in particular a rototranslation with respect to said second temperature deviation map ST2.

[0051] This then allows a third temperature deviation map ST3 to be defined by calculating a weighted average between the temperature deviation of each section i of the first temperature deviation map ST1 and the temperature deviation of the corresponding portion y of the second temperature deviation map ST2.

[0052] Said third temperature deviation map ST3 is then used by the method 1 of the invention according to the preferred embodiment to appropriately activate the temperature variation means distributed along the feed channel, adjusting the temperature of the molten glass flowing through each of said portions y, according to the deviations defined by the third temperature deviation map ST3 itself.

[0053] In detail, in order to appropriately activate the temperature variation means distributed along the feed channel, an absolute temperature map STSA is derived from this third temperature deviation map ST3, relating to relative deviations, which will then be effectively compared with the ideal temperature values to which to strive with the activation of the aforementioned temperature variation means.

[0054] In particular, the method 1 of the invention will provide for activating the aforesaid temperature variation means, in particular the heating elements and / or the cooling elements, in such a way as to make, for each of the portions y defined in the feed channel, the temperatures defined by the aforesaid absolute temperature map STSA approach the second predetermined ideal temperature values TM2y relative to the portions y.

[0055] It cannot be excluded, however, that according to a simplified version of the method of the invention, the step of measuring the temperature of the molten glass along the feed channel and the step of defining the second temperature deviation map ST2 would not be provided.

[0056] In this case, the method of the invention comprises defining only the first temperature deviation map ST1 by measuring the temperature of the sections i of the thermographic image, to uniquely associate each of the sections i with a portion y into which the cross-section of said feed channel is ideally divided, according to a cross-sectional plane orthogonal to the longitudinal extension axis of said feed channel, and to activate the temperature variation means distributed along said feed channel by adjusting the temperature of the molten glass flowing through each of said portions y, according to the deviations defined by said first temperature deviation map STi.

[0057] As mentioned above, the plant 300 for the production of glass bottles, schematically depicted in Figure 6, is also part of the invention.

[0058] This plant 300, in particular, comprises:

[0059] - a feed channel 301 for transporting molten glass from a melting furnace 302 to an IS type machine 303 for forming bottles, wherein temperature variation means 304, distributed along the same feed channel 301 and a plurality of thermocouples 305 are provided, each of said thermocouples 305 being arranged at a portion y of a plurality of portions y into which the cross-section of the feed channel 301 is ideally divided, according to a cross-sectional plane orthogonal to the longitudinal extension axis of said feed channel 301 ; in particular, each of said thermocouples 305 is configured to measure the temperature Meyof the molten glass flowing through each of the portions y into which the feed channel 301 is divided;

[0060] - a forming apparatus 306 of one or more drops G interposed between the feed channel 301 and the IS type machine 303;

[0061] - said IS type machine 303;

[0062] - electronic control means 307 configured to control the operation of the plant 300

[0063] According to the preferred embodiment of the invention, the plant 300 comprises two thermal imaging cameras 308a, 308b arranged in two distinct spatial positions in close proximity to the forming apparatus 306 and configured to simultaneously acquire two thermographic images of a drop produced by the same forming apparatus 306.

[0064] According to the invention, electronic control means 307 are configured to regulate the temperature of the molten glass along the feed channel 301 by the method of the invention described above.

[0065] It is not excluded that, according to a variant embodiment of the invention, the plant of the invention may comprise a single thermal imaging camera or more than two thermal imaging cameras. It has in practice been established that the invention achieves the intended objects.

[0066] In particular, the object of defining a method for optimising the temperature regulation of molten glass along the feed channel of a glass bottle production plant in order to optimise the homogeneity of the temperature of the drops formed by the forming apparatus of said plant is achieved.

[0067] Therefore, the object of defining a method of optimising the temperature regulation of the molten glass along the feed channel that will ensure greater uniformity of the chemical-physical characteristics of the drops formed by the forming apparatus and thus avoid defects in the finished product is achieved.

[0068] A further object achieved by the invention is to more precisely control the activation of the temperature variation means along the feed channel.

Claims

CLAIMS1 ) A method (1 ) implemented by a computer for regulating the temperature of molten glass along a feed channel of a plant for the production of glass objects, in particular glass bottles, characterised in that it provides for the following steps:- acquiring at least one thermographic image (100, 200) of at least one drop produced by the forming apparatus interposed between said feed channel and the IS type machine of said plant;- segmenting said thermographic image (100, 200) into a plurality of sections (i);- uniquely associating each of said sections (i) with a portion (y) into which the cross-section of said feed channel is divided, according to a sectional plane orthogonal to the longitudinal extension axis of said feed channel;- identifying the temperature deviation of each of said sections (i) with respect to a first predetermined ideal temperature value (TM-H) specific to each section (i), obtaining a first temperature deviation map (STi);- activating the temperature variation means distributed along said feed channel by adjusting the temperature of the molten glass flowing through each of said portions (y) according to the deviations defined by said first temperature deviation map (STi).2) Method (1 ) according to claim 1 , characterised in that for each of said drops two thermographic images (100, 200) are acquired simultaneously from two distinct spatial positions.3) Method according to claim 2, characterised in that:- each of said two thermographic images (100, 200) is segmented into the same number of sections (i);- one or more of said sections (i) of a first image (100) is linearly combined with one or more of the sections (i) of the second image (200);- a temperature deviation value is identified for each of said linear combinations with respect to a predetermined ideal temperature value in order to determine said first temperature deviation map (STi).4) Method (1 ) according to claim 3, characterised in that:- said linear combination step provides for uniquely associating each of said sections (i) of a first image (100) with one of the sections (i) of the second image (200);- said identification step provides for calculating the mean temperature value (Msi) of each pair of associated sections (i), and calculating the temperature deviation of each of said mean temperature values (Msi) with respect to said first predetermined ideal temperature value (TM-H) relative to each section (i).5) Method (1 ) according to any one of the preceding claims, characterised in that said number of sections (i) into which each of said thermographic images (100, 200) is segmented is equal to nine sections (i) distributed according to a 3x3 matrix.6) Method (1 ) according to any one of the preceding claims, characterised in that each of said first predetermined ideal temperature values (TM-H) is chosen equal to the mean of the temperature values of the sections (i) into which each of said images (100, 200) is segmented.7) Method (1 ) according to any one of the preceding claims, characterised in that said temperature deviation is calculated as a percentage deviation value with a sign with respect to the relative first predetermined ideal temperature value (TM-H).8) Method (1 ) according to any one of the preceding claims, characterised in that the following steps are further provided:- measuring the temperature (Mey) of the molten glass flowing through said feed channel for each of said portions (y) into which said feed channel is divided;- identifying the temperature deviation of each of said portions (y) with respect to a second predetermined ideal temperature value (TM2Y) specific to each portion (y), resulting in a second temperature deviation map (ST2).9) Method (1 ) according to claim 8, characterised in that each of said second predetermined ideal temperature values (TM2Y) is selected equal to the mean of the temperature values (Mey) of said portions (y).10) Method (1 ) according to claim 8 or 9, characterised in that said temperature deviation is calculated as a percentage deviation value with a sign with respect to said second predetermined ideal temperature value (TM2Y).11 ) Method (1 ) according to any one of claims 8 to 10, characterised in that said operation of uniquely associating each of said sections (i) of said thermographic images (100, 200) with a portion (y) of said feed channel provides for correlating the first temperature deviation map (ST1) with said second temperature deviation map (ST2) so as to obtain a closer correspondencebetween said deviations of said first temperature deviation map (STi) and said deviations of said second temperature deviation map (ST2).12) Method (1 ) according to claim 11 , characterised in that said correlation operation provides an overlap by rototranslation of said first temperature deviation map (ST1) with respect to said second temperature deviation map (ST2).13) Method (1 ) according to any one of claims 11 or 12, characterised in that it provides for:- subsequent to said correlation operation, the definition of a third temperature deviation map (ST3) by calculating a weighted average between said first temperature deviation map (ST1) and said second temperature deviation map (ST2);- activation of the temperature variation means distributed along said feed channel, adjusting the temperature of the molten glass flowing through each of said portions (y) according to the deviations defined by said third temperature deviation map (ST3).14) Plant (300) for the production of glass objects, in particular glass bottles, of the type comprising:- a feed channel (301 ) for transporting molten glass from a melting furnace (302) to an IS type machine (303) for forming said bottles, temperature variation means (304) distributed along said feed channel (301 ) and a plurality of thermocouples (305) being provided, each of said thermocouples (305) being arranged at a portion (y) of a plurality of portions (y) into which the cross-section of said feed channel (301 ) is ideally divided, according to a cross-sectional plane orthogonal to the longitudinal extension axis of said feed channel (301 ), each of said thermocouples (305) being configured to measure the temperature (Mey) of the molten glass flowing through each of said portions (y) into which said feed channel (301 ) is divided;- a forming apparatus (306) of one or more drops (G) interposed between said feed channel (301 ) and said IS type machine (303);- said IS type machine (303);- electronic control means (307) configured to control the operation of said plant (300); characterised in that it comprises at least one thermal imaging camera (308a, 308b) arranged in proximity to said forming apparatus (306) andconfigured to acquire at least one thermographic image (100, 200) of at least one drop produced by said forming apparatus (306), said electronic control means (307) being configured to regulate the temperature of the molten glass along said feed channel (301 ) by the method according to any one of the preceding claims.15) Plant (300) according to claim 13, characterised in that it comprises two thermal imaging cameras (308a, 308b) arranged in two distinct spatial positions with respect to said forming apparatus (306) and configured to simultaneously acquire two thermographic images (100, 200) of a drop from said two distinct spatial positions.

Images