EP2174331A1

EP2174331A1 - Furnace and method for producing a discharge lamp

Info

Publication number: EP2174331A1
Application number: EP07786502A
Authority: EP
Inventors: Frank Vollkommer; Lothar Hitzschke
Original assignee: Osram GmbH
Current assignee: Osram GmbH
Priority date: 2007-08-01
Filing date: 2007-08-01
Publication date: 2010-04-14
Also published as: KR20100038466A; JP2010534917A; TW200915381A; JP5165060B2; KR101174973B1; CN101772823A; CN101772823B; WO2009015677A1; US8348711B2; US20100197188A1

Abstract

The invention relates to a furnace (1) for producing a discharge lamp, comprising an outer furnace wall. It is characterized by a hollow body (2) that surrounds the outer furnace wall and is provided to receive discharge vessel parts (4, 5) and joints of the same to a discharge vessel (8) for the discharge lamp. The hollow body (2) further comprises a discharge gas supply (9) for flooding with a discharge gas such that a discharge vessel (8) provided in the hollow body (2) is filled with the same. The invention further relates to a production method for discharge lamps comprising such a furnace (1).

Description

description

Oven and method of making a discharge lamp

Technical area

The present invention relates to a furnace for producing a discharge lamp and to a manufacturing method for a discharge lamp having such a furnace.

State of the art

Discharge lamps have a closed and a discharge gas-containing discharge vessel. It is known to add a plurality of discharge vessel parts in an oven while supplying heat to a discharge vessel. In particular, it is known to add discharge vessel parts in a vacuum furnace under a discharge gas atmosphere.

DE 101 47 727 A1 shows a continuous furnace for joining discharge vessel parts to discharge vessels. In this case, the discharge vessel parts are introduced into an atmosphere with the discharge gas and added under this atmosphere.

Presentation of the invention

The object of the invention is to provide a furnace which is advantageous with regard to the production of a discharge lamp and a corresponding production method.

The invention relates to a furnace for producing a discharge lamp with an outer furnace wall, characterized by a surrounded by the outer furnace wall first hollow body for receiving discharge vessel parts and joints thereof to a discharge vessel for the discharge lamp and a discharge gas supply into the first vessel for flooding it with a discharge gas, so that a discharge vessel grouted in the first vessel is filled with this gas, and a manufacturing method using the same oven.

Preferred embodiments are the subject of the dependent claims and are also explained in more detail below. The disclosure relates both to the oven and to the manufacturing process, although this is not explicitly stated everywhere.

The invention is based on the finding that in discharge vessel parts which are grouted in a furnace under a discharge gas atmosphere, for example under a neon / xenon atmosphere, much larger amounts of discharge gas are reacted than finally enclosed in the grouted discharge vessels is. First, this is due to the usually comparatively large interior spaces of the furnace used. Secondly, depending on the furnace, the discharge gas can escape from the furnace - this is especially the case with a continuous furnace. Once this is economically disadvantageous, since some of the gases used, such as xenon, contribute significantly to the cost of the discharge lamps. Furthermore, the discharge gas may also have components in which a large conversion and a ventive escape into the environment is to be avoided for other reasons, such as chemically reactive and / or toxic gases. The invention is based on the idea of enclosing a comparatively small volume within the furnace with a hollow body and introducing the discharge gas into this smaller volume. The hollow body is flooded with the discharge gas and the discharge vessel parts are grouted inside the hollow body, so that the expanded discharge vessel is then filled with the discharge gas.

The hollow body can also have openings through which the discharge gas can escape from the hollow body into the oven and will be discussed later. Thus, an outward leading flow can be established. By means of the coils, the discharge vessel parts can be cleaned and any impurities present in the hollow body, such as particles and undesired gases, can also be kept away from the discharge vessel parts and removed from the hollow body.

Even if, in the case of a hollow body with openings, part of the discharge gas can escape from the hollow body, in any case only a comparatively small volume is flooded with the discharge gas, so that nevertheless the discharge gas conversion can be kept comparatively small.

It is also advantageous that the invention can use recourse to a known furnace or its technology. However, it is also possible to subsequently equip a furnace, which is already present in a factory, with a hollow body according to the invention.

In principle, a furnace according to the invention can also be used for

Exchanging the hollow body to be designed. Different hollow bodies can then be used for different discharges. - A -

tion lamp types to be optimized, for example, by enclosing the respective discharge vessel parts and discharge vessels as closely as possible.

Of particular importance is, assuming a substantially horizontal transport, the available clear height above the transport plane in the opening of the hollow body, such as a conveyor belt. Preferably, this clear height should be at most 5 times, particularly preferably at most 3 times, and in the most favorable case at most twice the maximum thickness of the discharge vessels or discharge vessel parts which must be driven through. It is of course also desirable to have a tight enclosure below the transport level, even though of lesser importance compared to the clear height.

The discharge gas with which the hollow body is flooded via the gas supply can preferably contain helium, neon, argon, xenon or a mixture of these gases, in particular neon alone. Furthermore, a neon / xenon mixture is preferred as the discharge gas.

Preferably, in the invention, no so-called. Batch operation, ie batch operation, carried out, d. H. a separate heating and cooling inlet was not run in each case with specific batches of discharge vessels or discharge vessel parts. Instead, the discharge cham- bers and discharge vessels are to be moved in and out of the continuously operated oven.

In a preferred embodiment, the furnace is a continuous furnace, which is particularly well suited for high throughput. An opening is used for introducing discharge vessel parts and another opening for discharging discharge vessels. In a continuous furnace is transported through the oven, such as a conveyor belt. An adapted hollow body has correspondingly a first opening for introducing discharge vessel parts and a second opening for discharging discharge vessel parts. The discharge vessel parts are transported into the hollow body, grouted therein, and the expanded discharge vessel parts are transported out of it again.

Preferably, the total area of the openings of the hollow body is significantly smaller than the total area of the openings in the outer furnace wall. By a smallest possible total area of the openings of the hollow body, the escape of discharge gas can be restricted. Here, too, the key factor is the area above the transport level. The cross-sectional area of the hollow body openings should preferably be at most 5 times, particularly preferably at most 3 times and in the most favorable case at most twice the corresponding cross-sectional area (in the same direction) of the discharge vessel parts or discharge vessels above the transport plane.

Preferably, the furnace is adapted to flow a gas along the openings of the hollow body along. By the flow of the penetration of impurities in the hollow body can be hindered and preferably largely prevented. The gas flowing along the openings acts as a flow process, comparable to air curtains at the entrance of large buildings. If the furnace according to the invention is designed as a continuous furnace, it preferably comprises a second hollow body. The further hollow body also has openings for the introduction and discharge of the discharge vessel parts, so that the discharge vessel parts can also be transported through the second hollow body. Along the transport path of the discharge vessel parts, the second hollow body is disposed in front of the first hollow body (for joining the discharge vessel parts). Via a gas supply, a spooling gas, preferably argon or helium, is introduced into this second hollow body for cleaning the discharge vessel parts. His openings are preferably energized as well as the openings of the first hollow body.

Preferably, the first hollow body in a continuous furnace is elongate, approximately rohrformig with substantially polygonal cross-section, wherein the openings for introducing the discharge vessel parts and discharging the discharge vessel preferably opposite to the ends of the hollow body. If impurities enter the first hollow body through the openings, the volume in the vicinity of the openings is particularly affected. Therefore, it is preferred if the first hollow body along the passage direction by at least a factor of 50 longer than high (based on internal clearances). More preferable is a factor of 80 or even 120 as the lower limit. For the second hollow body as well as for the first Hohlkoper an elongated design is preferred.

A preferred embodiment has a pump for pumping gases from the first hollow body. On the one hand can be established by the pumping a flow for coils On the other hand, the discharge gas or components of the discharge gas, in particular xenon, can be recovered.

It is further preferred to connect at least one pump via two Abpumpoffnungen to the first hollow body, in particular one pump in each case one of the two Abpumpoffnungen. In this case, a first of the Abpumpoffnungen is closer to the first opening and the second Abpumpoffnung closer to the second opening of the hollow body. Penetrating impurities can be pumped off, at least in part, via the two pumping out ports, so that the purity of the volume lying between the two pumping outflows can be further improved.

Preferably, there is another gas supply between see the first Abpumpoffnung and the first opening and still another gas supply between the second Abpumpoffnung and the second opening. Argon, helium or neon is preferably introduced from these two gas feeds and, above all, can be pumped out through the respective downstream pumping opening, so that a flow acting as a barrier can form. Optionally, parts of the gas introduced by the two gas supplies also escape from the openings of the hollow body and thus strengthen the barrier effect.

Preferably, the first hollow body is composed of several parts. The individual parts can - of course be connected gas-tight except for the Transportoffnungen. Alternatively, the discharge gas can also flow out of the hollow body between the parts due to an overpressure. In addition, vacuum channels can be longitudinally in the Be embedded edges of the parts and also prevent particles and unwanted gases by suction from entering the hollow body.

Preferably, the oven according to the invention is designed for the production of a flat radiator. In a flat radiator, the discharge vessel is flat and relatively large in size. Usually, the two large sides of the flat radiator are formed by two substantially plane-parallel plates. The plates can be structured and must, despite the name "flat radiator", not be flat in the strict sense of the word.

As mentioned, the invention also relates to a method for producing a discharge lamp in a furnace, as already described above. In particular, the production of a dielectrically impeded discharge lamp is preferred.

Preferably, the first hollow body is flooded with the discharge gas in such a way that it flows out of the openings of the hollow body during the flooding. In the case of multi-part hollow bodies, an outward flow between the parts is also preferred. Ingress of contaminants into the interior of the hollow body can be largely avoided.

In a continuous furnace, it is preferable to circulate the discharge vessel parts against its transport direction and the grooved discharge vessel along its transport direction with a gas. In this case, a component of the flow movement projected into the transport plane must be switched off. This can affect both gases in the hollow body and gases for energizing the openings of the Hollow body. Impurities are thus wound away from the actual joint zone.

Brief description of the drawings

In the following, exemplary embodiments of the invention are presented. In this case, individual features disclosed may also be essential to the invention in combinations other than those shown.

FIG. 1 shows a furnace according to the invention as a first exemplary embodiment.

Figure 2 shows a variant of the furnace of Figure 1 as a second exemplary embodiment.

FIG. 3 shows a further variant of the furnace from FIG. 1 as a third exemplary embodiment.

Figure 4 shows a schematic representation in the transport direction with a view of a Eingangsoffnung the first exemplary embodiment.

Figure 5 shows a schematic representation in the transport direction with a view of a Ausgangsoffnung the first exemplary embodiment.

Preferred embodiment of the invention

FIG. 1 shows a continuous furnace 1 for producing dielectrically impeded flat radiators. The continuous furnace 1 comprises a rohrformigen, about 160 times as long as high hollow body 2 (based on the internal clearances), so is not shown to scale. For example, dimensions of 8 m long, 60 cm wide and 5 cm high. This has an opening 3 for introducing discharge vessel parts 4 and 5.

In operation, the discharge vessel parts 4 and 5 are introduced into the hollow body 2 and passed therethrough with a known conveyor belt 6. From the opening 7 of the hollow body 2 then closed discharge vessels 8 leave the hollow body 2. It is therefore a "first" hollow body. The total area of the openings 3 and 7 of the hollow body 2 is significantly smaller than the total area of the openings (not shown) of the furnace 1.

Via gas feeds 9, a discharge gas is introduced into the hollow body 2 during operation, specifically helium, neon, argon or a mixture of these gases. The two openings 3 and 7 of the hollow body 2 are energized with helium or argon, so that impurities from the interior of the oven do not penetrate into the hollow body 2. In the hollow body 2 there is a discharge gas flow from the approximately centrally located gas feeds 9 to the openings 3 and 7, which results from a moderate overpressure.

The furnace heats the interior of the hollow body 2. The discharge vessel parts 4 and 5 are initially spaced apart in a manner known per se by SF ₆ glass spacers (see DE 101 47 727 A1). These soften during transport through the hollow body 2, so that the discharge vessel parts 4 and 5 lower each other and grooved together over a previously applied to the edges glass solder (not shown). In this case, discharge gas is trapped in the grooved discharge vessel 8. Figure 2 shows the furnace 1 of Figure 1. In contrast to Figure 1 but here a second hollow body 10 is introduced. The transport device 6 first guides the discharge vessel parts through the second hollow body 10 and then through the first hollow body 2. The second hollow body 10 is used for pre-cleaning of the discharge vessel parts, which are spooled in this hollow body via a gas supply 11 with argon or helium.

In Figure 3, the furnace 1 is shown in Figure 1, but with a changed (first) hollow body 12 and a pumping and recovery device 13 with two pumps 14, two volume flow meters 15 and a known device 16 for recovering noble gases. The hollow body 12 is now in two parts - with an upper lid 17 and a lower bottom 18 - constructed. Due to the chosen perspective, however, none of the "equatorial" circumferential seams are depicted. Bottom 18 and cover 17 abut each other over flat edges (not shown). In the edges of the bottom 18, a running along the entire edge length vacuum channel is introduced. Such a vacuum channel is known for example from DE 102 25 612 Al.

Here is introduced by gas feeds 9 either neon alone or a mixture of neon and xenon in the hollow body 12. Also in this hollow body 12 there is excess pressure. The gas contained in it therefore flows out of openings 3 and 7 and through the circumferential seam. In addition, pumping openings 19 are provided, via which the gas is pumped out of the hollow body 12 via the pumping and recovery device 13 and recovered. Depending on the gas composition, either xenon alone, Neon recovered alone or both xenon and neon.

Along the length of the hollow body 12 there are two further gas feeds 20, one each between one of the pumping opening 19 and the next opening 3 or 7. Additional argon, helium or neon are introduced into the hollow body 12 via these further gas feeds 20. The gas from these further gas feeds 20 flows, on the one hand, to the pumping out openings 19 and, on the other hand, to the respectively closest openings 3 and 7. Thus, the central foot region of the hollow body 12 is additionally protected from contamination from the furnace 1.

Figures 4 and 5 illustrate the already variously addressed dimensioning of the input and Ausgangsoffnung (or first and second opening) in relation to the dimensions of the discharge vessel parts or the discharge vessel. In the Einfahroffnung it is, as Figure 4 illustrates, to a larger height and a larger opening cross-section of the discharge vessel parts. There, the Einfahroffnung 3 seen in the transport direction is shown as a rectangle, wherein the hollow body 2 is drawn in a schematic manner as a slightly larger rectangle. In the approach opening 3, the discharge vessel lid 4 (see FIG. 1) is arranged relatively high up and arranged at the bottom and shown schematically the conveyor belt 6 (see FIG. The discharge vessel bottom 5 (see FIG. 1), which is covered by a glass solder layer 21 at the edge, lies on the conveyor belt 6. Upstanding spacers 22 made of SF ₆ -GIaS are shown on the left and right of the edge, which soften during the fugue process and ensure a controlled drop in the distance between them Allow discharge vessel lid 4 on the floor 5. The height of the discharge vessel parts here is the unavoidable total height of the discharge vessel bottom 5, glass solder layer 21, SF ₆ spacer 22 and discharge vessel lid 4, which altogether fills the clear height of the opening 3 to approximately 90%. With regard to the cross-sectional areas, the same principle applies in principle: The discharge area of the discharge vessel parts is determined by the projection area of the discharge vessel parts seen in this direction in the direction of transport plus the area enclosed between the discharge vessel floor 3 and lid 4 and the SF ₆ spacers 22. This is estimated to be good H of the cross-sectional area of the opening 3 above the conveyor belt. 6

Figure 5 shows in a similar manner the Ausfahroffnung 7, which is designed lower than the Einfahroffnung 3. After the joining step, the SF ₆ spacers 22 are printed together and not shown here, so that now the discharge vessel lid 4 rests on the discharge vessel bottom 5 or the glass solder layer 21. The entire unloading vessel 8 is thus lower than the structure in FIG. 4. The opening 7 is adapted to this, but this does not necessarily have to be the case. Here, the height of the discharge vessel 8 makes approximately H the clear height of the opening 7 above the conveyor belt 6. The cross-sectional area of the discharge vessel 8 is still significantly more than half of the cross-sectional area of the opening 7 above the conveyor belt 6.

Claims

claims

1. Furnace (1) for producing a discharge lamp with an outer furnace wall,

characterized by a first hollow body (2, 12) surrounded by the outer furnace wall for receiving discharge vessel parts (4, 5) and for joining them to a discharge vessel (8) for the discharge lamp and

a discharge gas supply (9) into the first hollow body (2, 12) for flooding it with a discharge gas, so that in the first hollow body (2, 12) joined discharge vessel (8) is filled with this gas.

2. Furnace (1) according to claim 1, designed as a continuous furnace (1), wherein the wall of the first hollow body (2, 12) has a first opening (3) for introducing discharge vessel parts (4, 5) and a second opening (7 ) for discharging discharge vessels (4, 5).

A furnace (1) as claimed in claim 2 adapted to receive a gas at the first opening (3) and at the second

Opening (7) from the outside on the first hollow body (2, 12) to flow along so that these gas streams impede the penetration of impurities in the first hollow body (2, 12) and impurities from the interior of the first hollow body (2 , 12) can take.

4. oven (1) according to claim 2 or 3, wherein the furnace

(1) a second hollow body (10) with a gas supply (11) for a spooling gas for winding the discharge gefaßteile (4, 5) when it is traversed by this, has.

5. Furnace (1) according to one of claims 2 to 4, wherein the first hollow body (2, 12) along the passage direction by at least a factor of 50 is longer than high.

6. Furnace (1) according to one of the preceding claims with a pump (14) for pumping gases from the first hollow body (2, 12).

7. Furnace (1) according to one of claims 2 to 5 and according to claim 6, in which the first hollow body (2, 12) has two pumping outlets (19) connected to a pump (14), a first of the pumping off (19) closer to the first opening (3) for introducing discharge vessel parts (4, 5) is located and the second of the Abpumpoffnungen (19) closer to the second opening (7) for discharging discharge feet (8).

8. furnace (1) according to claim 7 with at least two further gas feeds (20) in the first hollow body, wherein a first of the gas feeds (20) between the first Abpumpoffnung (19) and the first opening (3) of the hollow body (2 , 12) and a second one of the further gas feeds (20) is arranged between the second exhaust opening (19) and the second opening (7) thereof.

9. Furnace (1) according to one of claims 6 to 8 with a device (16) for recovering constituents of the discharge gas.

10. Furnace (1) according to one of the preceding claims, wherein the hollow body (2, 12) is composed of several parts.

11. A method of manufacturing a discharge lamp in an oven (1) having an outer furnace wall,

characterized by the steps:

Receiving discharge vessel parts (4, 5) in a first hollow body (2, 12) surrounded by the outer furnace wall,

Joining the discharge vessel parts (4, 5) to a discharge vessel (8) for the discharge lamp in the first hollow body (2, 12) and

Flooding the hollow body (2, 12) with a discharge gas via a discharge gas supply (9) before the completion of the joint, so that a discharge vessel (8) joined in the hollow body (2, 12) is filled with this gas.

12. The method according to claim 11, wherein the discharge gas, with which the hollow body (2, 12) is flooded, flows out during the flooding of the openings (3, 7) of the hollow body (2, 12).

13. The method of claim 11 or 12, wherein the furnace

(1) is designed as a continuous furnace (1), the discharge vessel parts (4, 5), contrary to their conveying direction With a gas flowing around it and the discharge vessel is flowed around in the direction of its transport direction with a gas.

14. The method according to any one of claims 11 to 13, wherein a first opening (3) of the first hollow body

(2, 12) for introducing discharge vessel parts (4, 5) and optionally a second opening (7) for discharging discharge vessels (4, 5) over a transport plane of the discharge vessel parts (4, 5) and discharge vessels (4, 5 ) has a clear height of at most 5 times the thickness of the discharge vessel parts (4, 5) and discharge vessels (4, 5) driven therethrough.

15. The method according to any one of claims 11 to 14, wherein a first opening (3) of the first hollow body

(2, 12) for introducing discharge vessel parts (4, 5) and optionally a second opening (7) for discharging discharge vessels (4, 5) over a transport plane of the discharge vessel parts (4, 5) and discharge vessels (4, 5 ) has a cross-sectional area perpendicular to the transport direction of at most 5 times the corresponding cross-sectional area of the discharge vessel parts (4, 5) and discharge vessels (4, 5) driven therethrough.

16. The method according to any one of claims 11 to 15, adapted for producing a flat radiator.

17. The method according to any one of claims 11 to 16 using a furnace (1) according to any one of claims 1 to 10.