DE2045994B2 - Method and device for determining the position of the edge of a strip of float glass floating on a molten metal bath - Google Patents

Description

The properties of tin and glass are <

The invention relates to a method and 65 namely in this wavelength range very below he device for determining the position of the Ran- different. In particular, the glass for this Be s one on a molten metal bath rich of the spectrum is opaque, and one observes floating float glass ribbon. so no longer pays attention to the surface of the enamel

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liquid metal bath through the float glass ribbon. But this is the edge of the float glass ribbon clearly.

In order to avoid disturbing reflections from above the tape during observation hot parts, such as the heating elements are detected, is in a further embodiment of the invention preferably the observed transition area is shielded from extraneous radiation.

It is advisable to use an inwardly inserted through the side wall of the float bath container, Observation device that works according to the tracking principle and determines the position of the edge of the float glass ribbon by observing the position of the tracking system.

In a further embodiment of the invention, the measured values can advantageously be used to control the manufacturing parameters the float bath system.

A device for carrying out the method according to the invention is essentially characterized through a tubular probe inserted through the side wall of the float glass container at least two cells sensitive to wavelengths from about 4 to 5 microns in such an arrangement, that the radiation emanating from the transition area between float glass ribbon and metal bath hits the two cells.

In a further embodiment of the invention, openings for are expedient at the front end of the probe the entry of rays falling on a plane mirror arranged at 45 ° to the optical axis provided, wherein the jacket formed by the walls of a cooling liquid and the interior the probe is traversed by an inert gas flowing out through the opening.

The probe is expediently mounted and is displaceable in the horizontal direction on sliding rails the lateral movement of the edge of the float glass ribbon can be traced by a drive motor which is controlled by the signals received from the cells.

In a further embodiment of the invention, it is expedient to proceed in such a way that the outer tube of the probe with the wall of the float bath tank via a horizontal displacement of the probe Bellows is tightly connected.

For example, embodiments of the invention will be described in more detail below with reference to the drawings explained. These show in

F i g. 1 is a view of a device in its position in the float bath furnace when observing the The transition area between the float glass ribbon and the free surface of the molten metal bath,

F i g. 2 shows a longitudinal section through part of the device according to FIG. 1 in a somewhat enlarged view,

3 shows a section along the line III-III of F i g. 2 and in

F i g. 4 is an electrical circuit diagram.

According to the embodiment of the invention shown, the device is formed by a periscope which enters via an opening 1 in the wall of the furnace 2. The outer cylindrical tube 3 of this periscope is supported by supports 4 which are firmly mounted on bearing collars 48 on rails 5 which are firmly connected to a C'Jlassisö. The carriers 4 can slide on the guides 5; the Virschiebung the periscope is ensured over a Schraube7 which drives a firmly connected to the pipe 3 la nut, said nut is controlled by a motor S.

The pipe penetrates a bellows 9, which ensures the passage seal. This bellows is with one of its edges on the tube by means of a? Storage collar 19 mounted, which is a sliding seal forms and allows the device to be adapted to different types of production. The other

ίο the edge of the bellows is on a frame 11 over Clamps 12 and locking members 13 attached.

One recognizes in FIG. 1 the observation port 14 of the device as well as the one on the tin bath floating glass track 15.

The F i g. 2 and 3 show the training in detail of the periscope and the various organs that make it up.

An inner tube 17 coaxial with the tube 3 forms a jacket, the chamber 24 of which is protected from a cooling fluid circulation is penetrated, which enters at 18 and exits at 19. Inside the tube 17 and coaxial too a tube 20 fixed at one end to an annular part 21 is provided for this, which tube 20 is in the tube 17

is held. At the other end, the tube 20 comprises a projection 22 which is attached to a ring part 23, which the chamber 24 forms, is attached. The existing between the tubes 17 and 29 space 25 is of Nitrogen permeated, which is introduced via a line 26 and via the observation port 14 exits. In the tube 20 openings 27 can be made for the passage of nitrogen into the interior of this tube be provided.

At the front end of the probe is a stainless steel plane mirror 28 at 45 ° to the optical Axis of the telescope arranged. This mirror is attached to a carrier 29 which is fixed to the ring part 21 is connected. According to the optical axis of the probe, it sends the observation port

opening 14 and the opening 47 of the tube 20 penetrating Radiation back.

The optical system comprises lines 30 made of fluorite in a frame 31 and a filter 32, which the Radiation with a wavelength less than 4 microns

eliminated. This filter is attached to a disc 33 which closes the end of the frame 31. The order the lenses and the filter can be guided by a threaded rod according to the axis of the probe 34 can be moved.

The cells 36 and 37 which are thin and rectangular are fastened between the insulating plates 38, which are held in a bearing 39 in a sleeve 40 are, which itself via an Ansa'zteil 41 between the attachment part 22 of the tube 40 and a Disk 35 is attached. In this sleeve there is also a bore 42 parallel to the optical axis, in which a shaft 44 carrying bearings 43 are arranged, the shaft being driven by a synchronous motor 58 is driven via the sleeve 45 of a coupling and ensures the rotation of a slotted disk 46, soft modulates the light beam absorbed by the cells.

In the electrical circuit diagram according to FIG. 4, the two paths of the two cells can be seen at A and B.

36 and 37, respectively. In each of these ways there are provided: an AC preamplifier 50, a threshold amplifier 51 with adjustable gain, which takes care of the shaping of the signal; a monostable

Rectifier 52, a delay stage 53 which provides for the filtering of the low-duration signals; a Power amplifier 54 and a relay 55 .. The contacts of this relay are with the logic control circuit 56 connected, to which diii contact switches 57 connect, which are used to actuate both ensure in the forward run as well as in the reverse run of the drive motor 8 and the displacements of the Secure the probe. This motor 8 is driven in reverse when the two cells 36, 37 are actuated, but run forward when none of these cells are energized. It stays dormant when only cell 37 is excited.

Of course, the displacement of the probe can also be hydraulic or pneumatic Drive take place, with corresponding solenoid valves controlled by the various 5'ellen will. The position of the edge of the disc or tape is determined by the position of the Probe by any convenient means

ίο marks, like a potentiometer, a Rotation angle must converter or the like.

1 sheet of drawings

Claims (8)

1 2 Knowing the position of the edge of such claims: Float glass ribbon is of great interest for manufacturing and enables control, for example 1. Procedure for determining the location of the organs that affect the glass throughput at the entrance to Edge of a on a molten metal 5 regulate the furnace, in such a way that a float glass ribbon with bath floating float glass tape, resulting in constant dimensions. The width of the characterized in that the over-float glass ribbon in the zone in which the float glass aisle area between the glass ribbon and the metal bath ribbon stops spreading, namely one of the outgoing radiation via only infrared rust characteristics that are best for the change Radiation-appealing observation instruments can be used from manufacturing parameters, is observed. There are already different probes for the observation 2. The method according to spoke 1, thereby paying attention to the position of the edge of a float glass bandea indicates that the observed transition has become known. For example, they became rich in electrics is shielded against extraneous radiation. those used that indicate the presence of the float glass 3. The method according to claim 1 or 2, to determine the marked 15 band. These electrodes are each drawn through the use of a wear that is difficult to measure Side wall of the float bath container inwards and have certain disadvantages, such as the material introduced, according to the after-run principle aibei contact with the glass. Even if they don't tend observation device and materials wettable by solid glass, such as position of the position of the edge of the float glass strip 20 graphite, they interfere with the flow of the by observing the position of the post-float glass ribbon and run the risk of sticking to the glass. which can lead to production disruptions. Of the 4. Method according to one or more of the use of other types of electrical encoders encounters Claims 1 to 3, characterized in that at least equally great difficulties. the measured values for the control of the manufacturing 25 You already have pneumatic tactile or parameters of the float bath system can be used. Sensing devices used. Have such organs 5. Device for carrying out the method, however, a fairly low sensitivity, since the rens after one or more of the previous edge of the float glass ribbon on a knife blade shape Claims, characterized by a tube has so that its thickness decreases very progressively; shaped by the side wall of the float glass 30 the device must be in the immediate vicinity Holder's introduced sor; de mii at least two for the float glass tape are located, which also leads to trouble Wavelengths of about 4 to 8 microns can be received. sensitive cells (36, 37) in such an arrangement, otherwise the known devices that the transition area between float preferably with successive tactile glass tape and metal bath outgoing radiation, followed by a rapid retraction in each case hits the two cells. hen, work, what their manufacture and their use 6. Device according to spoke 5, thereby making complicated under protective atmosphere,
indicates that at the front end of the probe to be able to work with the greatest possible safety to openings (47, 14) for the entry of one, it is therefore expedient to fall back on an optical measurement arranged at 45 ° to the optical axis. Experience shows that the rays falling on the plane mirror (28) provided that it is difficult to determine with accuracy the size of the gap formed by the walls (3, 17) between the free surface of the melt flux and the jacket of a cooling liquid Metal bath and the inert gas flowing out through the glass above the interior of the probe from a surface of the metal bath covered by the opening (14) flowing through 45 The optical solution thus also seemed not to be possible. and has not yet been practiced. This allowed 7. Device according to spoke 5 or 6, that can be explained by the fact that the furnace has a closed characterized in that the probe forms in a horizontal space, inside which glass and tin, Taler direction on slide rails (5) which are at very similar temperatures stored and the lateral movement of the edge 50 two low-emissivity, side by side song Form float glass ribbon lowing surfaces by a drive motor. The glass is even in the (8) is traceable, the temperature range sought by the cells between about 6OC (36, 37) received signals is controlled. and 1100 ° C quite transparent, so that an optimal 8. Device according to one or more of the device see mainly on the schmelzflüs claims 5 to 7, characterized in that 55 sige metal, which carries the float glass ribbon, on the outer tube (3) of the probe with the wall (2) speaks, the transition from the float glass ribbon zui of the float bath container over a horizontal exposed surface of the molten Me Shifting the probe allowing bellows tallbades is therefore not sufficiently recognizable. (9) is tightly connected. The invention provides a remedy here in that 60 the radiation emanating from the transition area between glass wall and metal bath over only au Infrared radiation appealing observation instru ments is observed.