METHOD AND APPARATUS FOR PROCESSING GLASS TUBE ENDS

Abstract

A method for processing glass tube ends is provided. The method includes providing a glass tube blank that has at least two tube end portions; actively cooling at least one tube end portion by a cooling station; and processing the at least one of the tube end portion.

Claims

1. A method for processing glass tube ends, comprising: providing a glass tube blank having two tube end portions; actively cooling at least one of the two tube end portions by a cooling station to provide an actively cooled end portion; and processing the actively cooled tube end portion.

2. The method according to claim 1, wherein the step of actively cooling comprises actively cooling to a predefined temperature.

3. The method according to claim 1, wherein the step of actively cooling comprises using a directed coolant flow onto the actively cooled end portion.

4. The method according to claim 1, wherein the step of actively cooling comprises: detecting the temperature of the at least one of the two tube end portions by a sensor; and controlling the cooling station on the basis of the detected temperature of the at least one of the two tube end portions.

5. The method according to claims 1, wherein the step of processing the actively cooled tube end portion comprises: scoring and rupturing the actively cooled tube end portion to provide a ruptured tube end portion; closing, without thermally pre-processing, the ruptured tube end portion to provide a closed tube end portion; and thermally post-processing the closed tube end portion.

6. A method for processing glass tube ends, comprising: conveying glass tube blanks in a conveying direction so that a length of the tube blanks is perpendicular to the conveying direction; actively cooling a tube end portion of each of the tube blanks as the tube blanks are conveyed in the conveying direction to provide a cooled tube end portion; and processing the cooled tube end portion as the tube blanks are conveyed in the conveying direction.

7. The method according to claim 6, wherein the step of actively cooling comprises actively cooling both tube end portions of the tube blanks.

8. The method according to claim 6, wherein the step of actively cooling comprises directing a coolant flow onto the tube end portion.

9. The method according to claim 8, wherein the step of directing the coolant flow comprises blowing the coolant flow through a slotted nozzle that extends parallel to the conveying direction.

10. The method according to claim 8, wherein the step of directing the coolant flow comprises blowing the coolant flow through two nozzles arranged on mutually opposite sides of a horizontal plane extending in the conveying direction.

11. The method according to claim 8, wherein the step of directing the coolant flow comprises blowing the coolant flow through a nozzle while moving the nozzle in the conveying direction synchronously with the tube blanks.

12. The method according to claims 6, wherein the step of actively cooling further comprises: detecting a temperature of the tube end portion; and controlling cooling of the tube end portion in dependence on the temperature.

13. The method according to claims 6, wherein the step of processing the cooled tube end portion comprises: scoring and rupturing the cooled tube end portion to provide a ruptured tube end portion; closing, without thermally pre-processing, the ruptured tube end portion to provide a closed tube end portion; and thermally post-processing the closed tube end portion.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0060] FIG. 1 shows a schematic view of an apparatus for processing glass tube ends, as is known from the prior art,

[0061] FIG. 2 shows a schematic view of an apparatus for processing glass tube ends having at least one cooling station,

[0062] FIG. 3 shows a first blower having a nozzle in side profile,

[0063] FIG. 4 shows a second blower having a nozzle in side profile,

[0064] FIG. 5 shows a third blower having two nozzles in side profile,

[0065] FIG. 6 shows a fourth blower having a U-shaped nozzle arrangement in side profile,

[0066] FIG. 7 shows a fifth blower having a concomitantly running nozzle in side profile,

[0067] FIG. 8 shows a section of an embodiment of the cooling station,

[0068] FIG. 9 shows the flow diagram of a method for processing glass tube ends, and

[0069] FIG. 10 shows the flow diagram of a further embodiment of a method for processing glass tube ends.

DETAILED DESCRIPTION

[0070] In the following, the directional indications left and right refer to left in the conveying direction and right in the conveying direction.

[0071] FIG. 1 shows a schematic view from above of an apparatus for processing glass tube ends, as is known from the prior art. The processing begins with the provision of glass tube blanks 10 having at least two tube end portions 11a and 11b. During provision, the glass tube blanks 10 have a temperature in a temperature range having a lower limit of 150 C., in particular of 200 C. and preferably 250 C., and an upper limit of 400 C., in particular of 350 C. and preferably 300 C. The glass tube blanks 10 are transported transversely in a conveying direction 14 by a conveying device 12. Here, transversely means that the glass tube blanks 10 extend perpendicularly or substantially perpendicularly to a conveying direction 14. The conveying direction 14 is determined by the conveying device 12. During conveyance by the conveying device 12, the tube end portions 11a and 11b of the glass tube blanks 10 project on the left and right beyond the conveying device 12, with the result that the tube end portions 11a and 11b can be processed by the following processing stations.

[0072] The apparatus illustrated is capable of processing different types of glass tubes in a processing line. These include closed glass tubes whose tube end portions are both closed, half-closed glass tubes in which only one tube end portion is closed, and open glass tubes in which both tube end portions are unclosed. Depending on which glass tube type is produced, use is made of different stations.

[0073] In a first exemplary processing step, contaminating or excess particles are removed from the left tube end portions 11a and right tube end portions 11b. This is achieved by the left station 22a for particle removal and right station 22b for particle removal.

[0074] A station 24a for closing the left tube end portions 11a is positioned downstream of the stations 22a and 22b for particle removal at a distance which is relatively short in relation to the overall length of the processing line. In general, the material for closing the tube end portions must be soft and shapeable. Therefore, it is appropriate for the station 24a for closing to be arranged rather at the start of the processing line, that is to say not far downstream of the station 22a for particle removal.

[0075] The situation for the station 24b for closing the right tube end portions 11b is different. Specifically, if the tube end portions 11b on the right are also closed, the right tube end portions 11b must first be provided with a hole for pressure equalization. The holing of the right tube end portions 11b is performed by a holing station 30. Since the exact position of the hole on the glass tube blanks 10 depends on a desired length or useful length of the finished glass tubes, the holing station 30 can be positioned in the conveying direction 14 only downstream of the burner station 26a, which follows the station 24a for closing on the left side. Thus, the position of the hole in the glass tube blank is ensured at a defined distance from the already finished left tube side. Furthermore, the temperature of the glass tube blanks 10, in particular of the right tube end portions 11b for the processing by the holing station 30, must be sufficiently cooled, with the result that the holing station 30 is positioned further downstream in the processing line.

[0076] Downstream of the holing station 30 there is then provided, on the right side, a further station 24b for closing, which closes the right tube end portions 11b.

[0077] For the thermal post-processing of the closed tube end portions 11a for the purpose of relaxation of the glass or avoidance of stress therein, a burner station 26a and 26b is positioned in the conveying direction 14 in each case directly downstream of the stations 24a and 24b for closing.

[0078] The tube end portions 11a and/or 11b are post-processed also in the case of glass tubes having one or two open tube ends. This post-processing can comprise, for example, a scoring and rupturing of the tube ends in order to obtain a defined length and a clean termination. For this purpose, the stations 28a and 28b for scoring and rupturing are provided on the left and on the right side. The stations 28a and 28b for scoring and rupturing are positioned far downstream in the processing line to ensure that the glass tube blanks 10 are cooled up to that point to an optimum temperature for this processing of less than 120 C. Burner stations 26a and 26b are also in each case again positioned adjoining the stations 28a and 28b for scoring and rupturing, wherein the burner station 26b actually adjoins the station 24b for closing because the distance between the latter and the station 28b for scoring and rupturing is comparatively small, with the result that a burner station can be used for the thermal post-processing of both processing steps. The burner stations 26a and 26b heat the ruptured tube end portions 11a and 11b again in order to smooth the edge which has resulted from the rupturing and to avoid unwanted stresses in the glass.

[0079] As has already been noted, not all processing stations are used for a product. The apparatus according to FIG. 1 is therefore designed for the production of different products. If an installation is designed for a product which always remains the same, the apparatus can comprise, for example, just one side of the processing line, that is to say for example only the left or only the right side. Furthermore, the apparatus can comprise just the stations 24a and/or 24b for closing or the stations 28a and/or 28b for scoring and rupturing.

[0080] FIG. 2 shows a schematic view from above of an embodiment of an apparatus according to the invention for processing glass tube ends which, in addition to the processing stations from FIG. 1, further comprises two cooling stations 16a and 16b. In the embodiment illustrated, the apparatus comprises a cooling station 16a on the left side and a cooling station 16b on the right side of the apparatus.

[0081] The cooling stations 16a and 16b are positioned at the start of the processing line. Consequently, the cooling stations 16a and 16b can cool the tube end portions 11a and 11b directly after the provision of the glass tube blanks 10. The cooling of the tube end portions 11a and 11b by the cooling stations 16a and 16b therefore has the effect not only that the temperature for the processing of the tube end portions 11a and 11b is regulated to a uniform level. In particular, the active cooling accelerates the cooling process by contrast to a passive cooling of the tube end portions 11a and 11b in air, as is the case in an apparatus without cooling station according to FIG. 1. The path is thus shortened between the start of the processing line and the first processing stations, which are here the stations 22a and 22b for particle removal. In particular, the stations 28a and 28b for scoring and rupturing can be moved upstream, since the optimum temperature therefor of below 120 C. is more quickly achieved.

[0082] For apparatuses without stations 24a and/or 24b for closing, it is possible, by contrast to an apparatus without cooling stations 16a and 16b, by using the cooling stations 16a and/or 16b, to save on a path of about 2 m or about 10% of the length of the processing line.

[0083] Furthermore, in the case of apparatuses which comprise both a station 28a for scoring and rupturing and a station 24a for closing, the number of burner stations 26a can be reduced. Whereas the apparatus shown in FIG. 1 requires two burner stations 26a for the thermal post-processing of the closed tube end portions 11a on the one hand and the thermal post-processing of the glass tubes cut to length in the station 28a on the other hand, it is possible by moving the station 28a for scoring and rupturing upstream to reduce the distance between the latter and the station 24a for closing to such an extent that a burner station 26a can be used for the thermal post-processing for both processing steps 28a and 24a. The apparatus according to the invention is accordingly preferably further developed in that the processing system has a station 28a for scoring and rupturing and a station 24a for closing, wherein only precisely one burner station 26a for a thermal post-processing adjoins the station 28a for scoring and rupturing and the station 24a for closing.

[0084] In alternative embodiments, instead of two cooling stations 16a or 16b, the apparatus can comprise just one on the right or left side.

[0085] FIG. 3 shows a part of a glass tube blank 10 with the right tube end portion 11b in a view in the conveying direction 14. A nozzle 18 of the cooling station 16b (not illustrated further here), which is designed, for example, as a slotted nozzle, is illustrated here in abstracted form positioned above the tube end portion 11b. In this embodiment, the nozzle 18 cools the tube end portion 11b from above.

[0086] FIG. 4 shows an arrangement similar to that of FIG. 3. The arrangement of FIG. 4 differs from the arrangement in FIG. 3 in that the nozzle 18 is arranged (schematically) below the tube end portion 11b. In this embodiment, the nozzle 18 cools the tube end portion 11b from below.

[0087] FIG. 5 shows a combination of the arrangements from FIGS. 3 and 4. The nozzles 18 shown here are likewise part of a cooling station 16b (not illustrated further here) and engage around the tube end portion 11b from two sides, that is to say at least partially, with the result that the upper and the lower subregion of the tube end portion 11b are cooled simultaneously.

[0088] FIG. 6 shows a further embodiment of the arrangement of nozzles around the tube end portion 11b of the glass tube blank 10. In this embodiment, a housing 18a engages around the tube end portion 11b on three sides, with the result that the tube end portion 11b can be cooled from above, from below and from the side. For this purpose, the nozzles are formed in the u-shaped housing 18a on the inner side as a plurality of holes (bores, oblong holes, slots, etc.) through which a coolant flow, in particular an air flow, is directed from a plurality of directions onto the tube end portion 11b. In this embodiment, the tube end portion 11b can be uniformly cooled in a particularly advantageous manner.

[0089] FIG. 7 shows a further arrangement of the nozzle 18 in relation to the tube end portion 11b of the glass tube blank 10. In this embodiment, the nozzle 18 is at least partially inserted into the glass tube blank 10 and can cool the tube end portion 11b from inside. In this embodiment, at least the nozzle 18 has to be configured to be movable in the conveying direction, with the result that the nozzle 18 can move along synchronously with the glass tube blank 10.

[0090] FIG. 8 shows a section in side view, that is to say with a viewing direction in or counter to the conveying direction, of an embodiment of the cooling station 16b. In the illustrated embodiment, the cooling station 16b comprises a compressor 20 which sucks in a coolant, preferably air, through a suction tube 21 and compresses it. The coolant is then forced by the compressor 20 through a coolant line 19, creating a coolant flow.

[0091] The cooling station 16b further comprises two nozzles 18 which are arranged above and below the tube end portion 11b. The nozzles 18 are fluidically connected to the compressor 20 via the coolant line 19. The nozzles 18 and the compressor 20 together form a unit, which is referred to as a blower. Furthermore, the nozzles 18 are arranged such that they direct the coolant flow onto the tube end portion 11b.

[0092] The cooling station 16b further comprises a cooling unit 17 through which the coolant line 19 is laid. The cooling unit 17 cools the coolant within the coolant line 19 while the coolant flows through the cooling unit 17. As a result, a coolant flow is produced from a precooled coolant.

[0093] FIG. 9 is a flow diagram illustrating the method according to the invention according to a first embodiment for processing glass tube ends. The method begins with step S02, in which a glass tube blank having at least one tube end portion is provided. While the glass tube blank is transported by a conveying device in a conveying direction, the glass tube blank runs through various processes. After the glass tube blank has been provided, the latter passes through a cooling station, which cools the at least one tube end portion of the glass tube blank in step S04. The glass tube blank is then transported to various processing stations, where the at least one tube end portion is further processed in a final step S06.

[0094] FIG. 10 is a flow diagram illustrating an alternative variant of the method according to the invention from FIG. 9. This variant also begins with the provision of a glass tube blank having at least one tube end portion in step S12. Next, the temperature of the at least one tube end portion is first of all detected by means of a first sensor in step S14. Here, particularly the average value of the tube end temperatures can be detected and the cooling power can be adapted to the detected temperature in step S16. The changes in the cooling power can act, during the cooling in step S18, on a plurality of tube end portions which are currently situated in the region of the cooling station.

[0095] If there is fitted an additional sensor for monitoring the outlet temperature of the tube ends downstream of the cooling path, the method reverts to step S14. Effects of the tube geometry or of the heat transfers to the tube ends during cooling can thus be incorporated into the regulation of the cooling power, and the cooling power can be correspondingly adapted.

[0096] In a further embodiment, the cooling path can be subdivided into a plurality of successively following cascades which each comprise a sensor, a cooling path and a control system. The cooling and hence the temperature accuracy of the outlet-side temperature of the tube end portion can be still further optimized with an increasing number of cascades.

[0097] Alternatively, a concomitantly running temperature sensor and a concomitantly running cooling module per tube end portion can be used for the cooling. In this embodiment, the temperature of each individual tube end portion is measured continuously. The cooling can thus be regulated in such a way that the desired target temperature of the respective tube end portion is optimally achieved at the outlet of the cooling path.

[0098] In any case, there finally follows the step S20 in which the at least one tube end portion is processed.

LIST OF REFERENCE SIGNS

[0099] 10 glass tube blank [0100] 11a tube end portion [0101] 11b tube end portion [0102] 12 conveying device [0103] 14 conveying direction [0104] 16a cooling station [0105] 16b cooling station [0106] 17 cooling unit [0107] 18 nozzle [0108] 18a housing [0109] 19 coolant line [0110] 20 compressor [0111] 21 suction tube [0112] 22a station for particle removal [0113] 22b station for particle removal [0114] 24a station for closing [0115] 24b station for closing [0116] 26a burner station [0117] 26b burner station [0118] 28a station for scoring and rupturing [0119] 28b station for scoring and rupturing [0120] 30 holing station [0121] S02 step of providing [0122] S04 step of cooling [0123] S06 step of processing [0124] S12 step of providing [0125] S14 step of detecting [0126] S16 step of controlling [0127] S18 step of cooling [0128] S20 step of processing