DE10304973B4 - Devices, control device and control method for the refining of glass - Google Patents

Abstract

Regulating device (1) for a plant (2) for melting and / or refining glass with control devices (50, 60), which form at least two control circuit planes,
characterized,
in that the regulating device (1) has a linking device (70) which can link a multiplicity of desired values and / or actual values over a plurality of control circuit levels,
- wherein the control circuit levels are hierarchically arranged and the at least one control device (50) of the higher-level control circuit level comprises a first presetting device (56) with which the at least one control device (60) of the subordinate control circuit level setpoints can be specified
wherein the control device (1) has a first detection device (10) for detecting at least one higher-order controlled variable of the following controlled variables for controlling the glass quality:
- volumetric bubble number density
- Bubble size distribution
Content of the gases dissolved in the molten glass,
and
- wherein the control device (1) comprises a second detection device (11) for detecting at least one subordinate controlled variable of the following process variables:
- temperature
- atmospheric residual pressure in ...

Description

The The invention relates to a control device and a method for Rules of a plant for melting and / or refining glass according to the characteristics the claims 1 and 23.

Lautering is understood to mean the removal of bubbles and dissolved gases from molten glass, which are continuous in devices such as those in the application DE 199 39 779 A1 can be performed by the applicant described attachment.

Usually will the purification made of glass melts by adding substances that at a temperature increase Gases release gases into existing bubbles. diffuse and enlarge them. Thereby can the bubbles rise faster from the melt and out of this escape.

In continuously operated plants, the refining can be done by applying reduced pressure. This method and its embodiments are described, for example, in the following documents:
In EP 0 989 099 A1 . EP 0967 180 B1 . EP 0 231 518 B1 and JP 11255519 A For example, methods and apparatus for vacuum annealing are described in general. US 1,598,308 describes a refining unit with riser, horizontal refining chamber and downpipe. In JP 09156932 A . JP 02188430 A and EP 1 044 929 A1 Degassing is described by storing the glass melt under reduced pressure for a certain time. The documents EP 0 253 188 A1 . US 4,919,700 . JP 07291633 A and US 4,704,153 In particular, the elimination of foam have the goal. For this purpose, the addition of substances such as water, which break the foam, a suitable design of the glass flow cross-section or the heating of the headspace of the vacuum chamber is applied.

In order to remove foam, refining gas can also be produced by refining agents in the molten glass, for example according to Applicant's application DE 199 39 771 A1 ,

When refining, furthermore, the high-frequency explanation method developed by the Applicant can be used without the use of toxic refining agents such as As ₂ O ₃ or Sb ₂ O ₃ . This method is based on that the melt is passed through an alternating electric field of a coil, wherein the field is coupled directly into the glass. The aggregate walls are designed as skulls, whereby the glass melt reaches a temperature of more than 1900 ° C. The high-frequency explanation method is described in detail in the following patents:
DE 199 39 773 A1 and DE 199 39 786 A1 relate to devices and methods, wherein in glass, which is located in cooled refining vessels, from a high-frequency device inductively radio frequency energy is coupled into the molten glass in the refining vessel.

Further, in refining, the high-temperature clarification method developed by the applicant can be used. In the application DE 102 56 657.7 describes a heating device and a melting unit, which allow efficient heating of the melt due to improved cooling. In DE 102 56 594.5 describe a method and apparatus for heating melts so that the walls of the melter can be cooled sufficiently and at the same time more energy is supplied to the melt than is withdrawn through the cooled walls.

Due to the reactions occurring during the melting process, a glass melt contains gases in chemically and / or physically dissolved form as well as in the form of bubbles. The goal of any refining process is to remove, as far as possible, the bubbles contained in the molten glass and at least part of the dissolved gases. These gases include, for example, H ₂ O, CO ₂ , SO ₂ , N ₂ , O ₂ and Ar.

Around the refining process perform regulated to be able to it is necessary to know the physico-chemical relationships. In order to build a regulation, it is necessary, these relationships to describe in a model to measure the necessary material and process parameters as well as strategies and algorithms for the regulation of the refining process to develop.

To work out a solution for this task, the bubbles introduced into the melt are considered first. Immediately after the melting process, the bubbles in the melt are in a certain location-dependent volume density, size distribution and composition. Approximately At this time, it can be assumed that the composition of the bubbles substantially coincides with that in the surrounding glass melt and still deviates little from its surroundings. The convection present in the smelting unit transports the bubbles to other locations at different temperatures. Due to their buoyancy, the bubbles have the tendency to ascend contrary to the gravitational acceleration or other additionally impressed accelerations.

As a general rule the following measures are taken to reduce the number of bubbles in the melt in question: reducing the number of starting bubbles immediately when melting, shortening the bubble ascent paths by bringing the bubbles close to the glass bath, increasing the bubble ascent rate in the molten glass, the absorption the remaining bubbles from the melt and the lowering of the Gas content of the melt.

If the raw materials, their composition and the possibilities for their preparation as well as the refining agent not changed can be can through the temperature control of the process to be acted on the starting bubbles and so the number the starting bubbles are reduced immediately during melting.

To the Shorten the bubble ascent paths by bringing the bubbles close to the glass bath for example, an area in a smelting unit is suitable, in which the glass bath depth is greatly reduced. Also by a deft adjustment of convection can be blistered Areas very close and very frequent to the glass surface transport.

With regard to increasing the bubble ascent rate in the molten glass, the bubble ascent rate is considered:
the bubble ascent rate v is given according to Stokes law by:

there denote ρ the Density and η the viscosity the molten glass, g the gravitational acceleration and r the bubble radius.

you recognizes that an increase the acceleration g, for example by centrifuging, as well as by a decrease in the viscosity η, for example by a temperature increase, and especially strong by increasing the bubble radius r the Bubble ascent rate v can be increased. Because of the square dependence the bubble ascent rate from the bubble radius is preferably the latter sought. An appreciable enlargement of the bladder may be preferred by Diffusion of gases from the melt can be effected in the bubbles.

gegeben durch

mit folgenden Zusatzgleichungen

The temporal change of the bubble radius ṙ is in the case of a temporally stationary temperature field

given by

with the following additional equations

R:

Gaskonstante

T:

Temperatur

D_i:

Diffusionskonstante

L_i

Löslichkeit

Sh:

Sherwood-Zahl

p_i,G:

Druck der i-ten Gasspezies in der Glasschmelze

p_i,B:

Druck der i-ten Gasspezies in der Blase

p_A:

Atmosphärendruck

ρ:

Dichte der Glasschmelze

g:

Erdbeschleunigung

z:

Tiefe der Blase

σ:

Oberflächenspannung

ν:

die im ortsfesten Bezugssystem gegebene Geschwindigkeit der Blase

Where:

R:

gas constant

T:

temperature

D _i :

diffusion constant

L _i

solubility

sh:

Sherwood number

p _{i, G} :

Pressure of the i-th gas species in the glass melt

p _{i, B} :

Pressure of the i th gas species in the bubble

p _A :

atmospheric pressure

ρ:

Density of the glass melt

G:

acceleration of gravity

z:

Depth of the bladder

σ:

surface tension

ν :

the velocity of the bubble given in the fixed frame of reference

• 1. der in die Blase eindiffundierten Stoffmenge
  
  aufgrund der Partialdruckdifferenz p_i,G – P_{i,B ,}
• 2. der Änderung des Atmosphärendrucks – r / 3ṗ_A
• 3. der Änderung des hydrostatischen Drucks rρg / 3ż, und
• 4. der Bewegung der Blase in einem räumlich inhomogenen Temperaturfeld
  

The temporal change of the bubble radius ṙ is made up of the following terms which characterize the respective driving force:

• 1. the amount of material diffused into the bubble
  
  due to the partial pressure difference p _{i, G} - P _{i, B ,}
• 2. the change of the atmospheric pressure - r / 3ṗ _A
• 3. the change of the hydrostatic pressure rρg / 3ż, and
• 4. The movement of the bubble in a spatially inhomogeneous temperature field
  

The enlargement of bubbles in conventional refining processes is generally carried out by the fact that a substance added to the melt in an adjusted concentration (for example As ₂ O ₅ , SnO ₄ , HCl) liberates a gas above a certain temperature. This gas diffuses into, already existing bubbles or leads to the formation of new bubbles, if the gas pressure is so high that it can not dissipate by diffusion sufficiently fast. By varying the chemical composition of the added substance, its concentration, the glass composition, and the temperature and flow field in the production aggregate, the degree of bubble enlargement and the associated bubble removal can be adjusted. This requires knowledge of the concentration of the initial bubbles, their composition, volume density, size distribution and starting locations. In addition, the concentration or the partial pressure of the dissolved gases in the melt must be known.

The resorption of the remaining bubbles is crucial for the removal of the bubbles which have not escaped from the melt and the contents of which consists of such gases as the temperature of the melt is lowered. have a much lower partial pressure. In addition, the absorption of gases in a bubble can be improved by increasing the atmospheric gas pressure. This process is supported by the surface tension σ of the glass melt (typically 0.3 N / m) when the bubbles have become sufficiently small. The surface tension leads to a pressure p _Os , which is given by

For very small bubbles, which means r <20 μm, p _{os can become} very large.

Dissolved gases can when crossing the boiling line, either at constant pressure by increasing the Temperature or at constant temperature by lowering the pressure happen uncontrollably in the form of bubbles (reboil). Furthermore, it may interact with the surfaces of the refractory material for the separation of bubbles. To reduce the extent this undesirable Processes, in addition to the removal of the bubbles and the lowering the gas content of a melt sought.

The Lowering the gas content sets a significant mass transfer from gas to the glass surface ahead. in principle the gas content of a melt can be lowered by the one hand a preferably size Partial pressure difference for the gases to be removed is built up, and on the other hand, the mass transfer facilitated by a high temperature and the largest possible mass transfer area becomes. After all should be possible a lot of gas to the gas bath surface be transported where it can escape easily. In the conventional lautering on the other hand, only a small amount of dissolved gas in the melt away.

When activities to increase the partial pressure difference for the dissolved in the melt Gases are, for example, the passage of a dissimilar purge gas through the molten glass or the lowering of the ambient pressure. Advantageous for the Pressurized refining is that all gases are removed without a purge gas in. remain behind the melt can. When using a purge gas Process problems such as Reboil can not be completely ruled out a part of the purge gas can dissolve in the melt.

Over small distances, the gases are transported in the glass melt by diffusion, which is very slow: typical diffusion coefficients for gases in glass melts are about 10 ^-10 m ² s ^-1 . In addition to the Glasbadoberfläche therefore the largest possible internal gas exchange surface must be created. For this purpose, bubbles are suitable in a sufficiently large volume density, which already have a high specific surface area. These bubbles are either passed through the melt actively (eg by fine bubbling) or arise as a result of a negative pressure due to heterogeneous nucleation. Bubble gas transport, in addition to its buoyancy rate, may also be assisted by convection of these bubbles to the glass bath surface.

So that the bubbles can be removed stably and without interference while simultaneously reducing the residual gas content, the necessary processes must take place in a certain way between the inlet and outlet of the glass in a refining unit. In order to control these processes targeted, therefore, a reliable control is required. One possibility for the regulation of processes for the production of las is, for example, in the patents FR 2 781 786 "Device for controlling the melting and / or degassing of glass melting furnaces" described in DE / EP 097668ST1.

A Controlled system is in accordance with DIN 19226 (Compare there is a control difference between a leader and a Controlled variable. The Controlled variable influenced by disturbances. The controller output is effective as a manipulated variable on Actuator, whereby the controlled variable is influenced. often is also the reference in literature as setpoint and the controlled variable as actual value designated. In principle, it is known how the refining of glass is carried out got to. This includes, as described, the elimination of bubbles and a significant Reduction of dissolved gases in the melt. However, experience tells us that this process is not desirable Measure stable carried out can be. In addition, the number of bubbles in the product can not be without more safely kept below a certain limit become. The complexity The procedure therefore requires a control concept based on a variety of input and output sizes (Multiple Input Multiple output control: MIMO control).

It has been found that the stability and durability of refining devices and methods can be significantly improved by incorporating control. It has also been shown that the control in the manner described above is very helpful to prevent damage and other dangerous or harmful to product quality influencing factors (eg freezing of the glass in the plant, excessive corrosion, new blister formation in the refining - in the area of blister wax to minimize excessive foaming).

Out the circumstances described above Therefore, the object of the invention, a control device for one Plant for melting and / or refining of glass available to put that over a stable process control addition the targeted influencing of a quality parameter, in particular the bubbles in the product allowed.

Is solved this task in a simple way by a device with the features of claim 1. Further, in claim 23 a Specified method, with a regulation using the device carried out can be. Advantageous developments can be found in the respective associated subclaims.

The Regulating device for a plant for melting and / or refining glass has two control devices which form at least two control circuit levels. In this control system at least one manipulated variable is determined, by having at least one controlled variable as well at least one corresponding to this controlled variable Process size recorded becomes. The rules of the invention consists of a hierarchically structured controller structure together.

Of the Regulator of the highest Level is responsible for the quality function the bubble density and the residual gas content. Low level regulator serve the self-sufficient regulation of the individual process parameters: for example, the foam height in the refining unit with means of top heat and injection of substances for acceleration the foam decomposition are regulated. A constant glass bath depth in the refining unit For example, by adjusting the residual pressure under consideration regulated by throughput and temperature.

The Control device according to the invention also has a linking device on which a plurality of setpoints and / or actual values over several Link control loop levels together. In particular, works the linking device according to a so-called Multiple Input Multiple Output System (MIMO system). By linking the plurality of setpoint and / or actual values over several control loop levels away the invention a separation of different process steps, wherein but at the same time with a single regulation the parent Process goal can be controlled: is, for example, a greater reduction the residual gas content desired, you would preferably strive for a separation of the process steps "reduction of the gas content" and "bubble removal". This The process of gas removal must be completed before the bubble is removed and, because it is associated with bubble production, carefully be matched to the process of bladder removal. Such Voting of different process steps on each other is done with the Invention possible in an advantageous manner. The loop connection can in addition to the model-based control strategies of the MIMO procedures Furthermore at least one of the following strategies include: PID, fuzzy, neural Networks and adaptive regulations.

ever after abandonment of the lower-level controller can already input data adapted setpoints are determined. As setpoints can thereby not only readings, but also derived quantities are used. These Advantages are realized by the fact that the control circuit levels are hierarchical are ordered, wherein the at least one control device of the respective parent Control circuit level comprises a first default device, with which the at least one control device of each subordinate Control circuit level setpoints can be specified.

The at least one control device of each higher-level control circuit level also includes a second presetting device, with the direct manipulated variables specified can be. Because in this way high-level next to setpoints directly determines control variables can be allows the invention (if necessary) to save a control stage. So can the manipulated variable directly can be determined from input data, thus the complexity of the rules be significantly reduced. Further rationalization of the device serves the possibility according to the invention in that a default device specifies the first default device the setpoints and the second presetting means for setting the Command values includes.

• – Temperatur
• – atmosphärischer Restdruck in der Läuterkammer
• – Heizleistung
• – Heizleistung in vor- und/oder nachgeschalteten Prozessschritten
• – Gemengefeuchte
• – Gemengelage
• – Gemengeform
• – Volumenstrom durch die Glasdüsen
• – Glasstand in der Schmelzwanne und/oder in der Läuterwanne und/oder in der Rinne und/oder im Rührtiegel
• – Viskosität des Glases
• – Durchsatz des Glases
• – Sauerstoffpartialdruck des Glases
• – Wassergehalt des Glases
• – Sauerstoffpartialdruck des Abgases
• – Ofendruck in der Schmelzwanne
• – Schaumhöhe
• – Form des Schaums
• – Lage des Schaums
• – Druck und/oder Volumenstrom des Schutzgases
• – Blasenbildungsrate in der Schmelzwanne
• – Rührerdrehzahl
• – Sauerstoffpartialdruck an Edelmetallbauteilen.

Because the context of the glass quality and the controlled variables as well as various influencing parameters can be controlled with the regulation according to the invention, the method according to the invention makes it possible to control the complex variable "quality". The glass quality will depend on the type of glass and / or the plant for melting and / or refining glass as a function of at least one of the consequences determined by the controlled variables: volumetric number of bubbles, bubble size distribution and content of dissolved gases in the glass melt. For this purpose, at least one first detection device is provided for the control device, which detects at least one controlled variable, in particular one of said control variables. By detecting the control variables, the setpoint values are predetermined for the control device. For feeding the actual values into the control, the control device provides a second detection device which can detect at least one process variable, in particular one of the following process variables:

• - temperature
• - atmospheric residual pressure in the refining chamber
• - Heating capacity
• - Heating power in upstream and / or downstream process steps
• - Mixture moisture
• - Mixed situation
• - Mixture form
• - Volume flow through the glass nozzles
• - Glass level in the melting tank and / or in the refining tank and / or in the gutter and / or in the agitating crucible
• - Viscosity of the glass
• - Throughput of the glass
• - Partial oxygen pressure of the glass
• - Water content of the glass
• - Oxygen partial pressure of the exhaust gas
• - Furnace pressure in the melting tank
• - foam height
• - Shape of the foam
• - Location of the foam
• - Pressure and / or flow rate of inert gas
• - Blistering rate in the melting tank
• - Stirrer speed
• - Partial oxygen pressure on precious metal components.

To the Convert the detected size into Signal sees the invention at least a first processing device before, in which at least one of the process variables can be processed. A comparison with corresponding values, for example In addition, it allows monitoring of the process.

The Control device according to the invention is further characterized by at least a first output device, which can output at least one of the process variables. To this Way, the signal can be forwarded, and there is the possibility to query the forwarded value, so by comparing the forwarded processed with the detected value a control option for the interaction the detection, processing and output device given is.

Around the sizes of interest to be able to detect a particularly simple manner, sees the control device according to the invention in that the detection device has at least one measuring device for measuring at least one control, process or manipulated variable has.

advantageously, is the control device according to the invention for various Plants usable, in particular the invention offers the possibility the control device with one of the following components constructed arbitrarily Controlled system to use: The plant for melting and / or refining Glass can be an insertion machine, a melting tank, an oven, a refining, a chaplet, a riser, a horizontal refining chamber, a downpipe, a Conditioning part, a device for injecting surface-active substances, a Device for introducing inert gas, a homogenization system, a feeder, a device for hot forming, a cold end, a blowing nozzle, a pump and a stirrer include.

The Measuring device according to the invention may be arranged at at least one of the following locations: melting tank, refining, refining crucible, Riser, horizontal refining chamber, Downpipe, conditioning part, homogenization system, feeder, Facility for the hot forming or cold end. The position of the measuring device is thus advantageously variable, allowing multiple measuring devices for spatially resolved control possible are. As long as at one of these places a minimum of information is determined, the further measurement data acquisition in any way limited.

To the Adjusting at least one manipulated variable sees the control device according to the invention furthermore, an adjusting device. This will allow already with a single adjustment if necessary. on complex Way in the control device determined control target, namely the a manipulated variable in the Feed back process and so make the actual regulation.

• – Wasserzugabemenge in das Gemenge
• – Wassereindüsungsmenge in die Oberofenatmosphäre
• – Oxidationsmittelzumischungsmenge für fossile Brennstoffe
• – Volumenstrom durch die Blasdüsen
• – Verhältnis zwischen Brennstoff und Oxidationsmittel
• – Position und/oder Taktzahl und/oder Pausenzeiten und/oder Stoffmenge pro Takt der Einlegemaschine
• – Volumenstrom und/oder Zusammensetzung der Eindüsung oberflächenaktiver Substanzen
• – Leistungsdichte im Schaum
• – Durchsatz des Glases
• – Saugleistung der Pumpen
• – Leckraten
• – Höhe der Läuterbank
• – Heizleistung
• – Druck und/oder Volumenstrom des Schutzgases
• – Rührerdrehzahl
• – Gaszusammensetzung an der glasabgewandten Oberfläche von Edelmetallbauteilen.

As well as the position of the measuring device, the position of the adjusting device is variable, so that in spatially large extent of the controlled system coupling of the manipulated variable in several places is possible. According to the invention, the adjusting device is provided at at least one of the following locations: melting tank, refining chamber, refining crucible, riser pipe, horizontal fining chamber, downpipe, conditioning part, homogenizing system, feeder or device for hot forming. The regulation described so far detects the manipulated variables indirectly from deviations of the setpoint values from the actual values. Irrespective of this, the invention provides a further possibility of checking the manipulated variables, in that at least one of the following manipulated variables can be detected directly in a third detection device:

• - Addition of water in the mixture
• - Water injection amount in the upper furnace atmosphere
• - Oxidant mixing rate for fossil fuels
• - Volume flow through the blowing nozzles
• - Ratio between fuel and oxidant
• - Position and / or number of cycles and / or pauses and / or amount of substance per cycle of the insertion machine
• - Volume flow and / or composition of the injection of surface-active substances
• - Power density in the foam
• - Throughput of the glass
• - Suction power of the pumps
• - Leak rates
• - Height of the refining bank
• - Heating capacity
• - Pressure and / or flow rate of inert gas
• - Stirrer speed
• - Gas composition on the glass-facing surface of precious metal components.

In at least one second processing device can at least one of the manipulated variables are processed. Thus, a comparison with corresponding values, e.g. at other measuring locations possible, and the manipulated variable itself can thus be adjusted.

In at least one second output device can be at least one of Manipulated variables are output. Analogous to the first output device for outputting a process variable is so the possibility for the Forward the signal and for given a query of the forwarded signal, so that a Control of the scheme can be made.

The Control device further comprises a compensation device, which the influence of disturbances like especially day / night fluctuations, barometric pressure fluctuations, humidity fluctuations the manipulated variables and / or Compensate control variables can. Thus, the invention provides a particularly simple way for relieving the control device by filtering out disturbances from the environment become. The scheme does not have to be such uncertain, difficult be designed to be calculated fluctuations. Therefore, the invention offers the possibility for one finer tuning of the scheme, which is therefore more accurate.

Next the acquisition of setpoints from the process, the measurement effort be reduced by assigning fixed setpoints. The regulation can over it different parameters adapted to different strategies be changed without the control device itself in their construction got to. Therefore sees the invention in a particularly simple way an archiving device before, which the setpoints for Controlled variables and / or Can archive parameters of the control device. These saved Setpoints also become with actual values over the different control loops levels linked, so that they work in the same way as the detected setpoints in the Regulating device can be processed.

By means of an input device, the current production target can be entered. This detection of the immediate target size on the one hand allows an evaluation with regard to the actual realization of the planned control target by comparing the input current production target with the result of the production and thus, if necessary, an adjustment of the control, if there are deviations. On the other hand, different process objectives can be selected, so that the control variable to ver various requirements can be set without having to change the control device or the underlying method itself.

In In this respect, the invention offers the great advantage, goal-oriented To be able to save values by the archiving device, the setpoint values for the controlled variables and / or the parameters of the control devices according to the current Can archive production target.

Because the control device according to the invention, as described above, extremely variable can be used, the scheme in different versions the system are used, for example in a device for melting and / or refining, in a low-pressure melting and / or annealing unit in a high frequency heated Melting and / or Läuteranlage or in a directly electrically heated melting and / or Läuteranlage.

The inventive method not only serves, as described above, the execution of the control concept according to the invention in the control device, but also the evaluation of controllability and the control behavior of the production plant and its stability already in the design phase of the plant. This is achieved by that the operating behavior of the plant for melting and / or refining Glass is determined by simulation calculations and / or simulated. By creating a simulation model of the real production plant can then by analyzing the simulation calculations the control behavior individual components and / or the whole system in a simpler way Be deduced way. Thus, the invention offers the possibility Align the scheme in advance with the reality of the process.

The Result of the simulation can be used to determine the control behavior at least one process level are used. Compared to the purely empirical approach of tuning the scheme can be based on this Way a reliable Voting with significantly less iteration steps to adjust the Parameters are made. Deviations from predefined setpoints can early recognized and according to the degree of deviation after glass and / or process-dependent Weighting regulations are counteracted (statistical process control).

A Such tuning can according to the invention in an advantageous manner especially done quickly by for at least one process level from the result of the simulation for Determining the control behavior a real-time control model is derived.

Around the possibility for quick tuning with significantly less iteration steps for the inventive method to use extensively, the invention sees further possibilities before: the result of the simulation can be used to determine the control behavior the entire plant used for melting and / or refining of glass become. At the same time, however, the possibility exists to determine the at least one manipulated variable from at least a setpoint and at least one actual value an empirically developed To apply the rule. Advantageously, the manipulated variable in the inventive method from at least one setpoint and at least one actual value using one on a phenomenological Determined model-based regulation. To determine the manipulated variable can another one on a chemical and / or physical model are applied. It is also possible to have one To apply a rule which consists of a combination of an empirical developed prescription and / or one on a phenomenological Model-based prescription and / or one based on a chemical and / or physical model-based prescription becomes.

By doing in each control loop, the parameters of the regulations for determining the at least one manipulated variable based a comparison with the process data to the current conditions adjusted, the advantage is easily created, that the regulation reacts variably to the current conditions.

The for the Comparison used process data can from the current production be derived. This allows the control with a process control system be coupled; This is particularly advantageous as the required Data already available in the process control system. The regulation according to the invention However, this is not due to the existence of a process control system instructed: the for The process data used for the comparison can also be determined in experiments become.

In the previous description, the case was considered that the control device according to the invention or the method for the regulation of the glass quality is used for a given process goal. However, the invention also offers the possibility, in addition to the glass quality, the change of Pro to regulate production parameters. In this way, with the invention, a reliable product change can be carried out automatically.

The The invention will be described below with reference to the accompanying drawings described in more detail. The same components will be on all drawings marked with the same reference numerals.

It demonstrate:

1 schematic representation of a regulation according to DIN 19226,

2 schematic representation of a plant for melting and / or refining glass,

3 Flow chart of the control according to the invention,

4 Schematic diagram of a refining unit,

5 schematic representation of an absolute pressure control,

6 schematic representation of a differential pressure control,

7 schematic representation of a glass level control,

8th Flow chart for the control of the vacuum fermentation,

9 Flowchart for the regulation of high frequency refining.

Out 2 is a general scheme for a facility 500 for melting and / or refining of glass. The attachment 500 consists of a melting tank 510 , a lauter tub 520 and a gutter 530 , The pictured plant 500 has a separate melting tank 510 and lauter tub 520 on; in principle, however, both may also be combined to a tub or divide into other sections. As starting material for the produced as possible bubble-free glass melt 600 is the mixture 650 gets into the melting tank 510 given up. In the melting tank 510 melts the mixture 650 one; so that the glass melt 600 is formed. The melt 600 arrives later in the lauter tub 520 in which removing the bubbles from the molten glass 600 is carried out. The purified glass melt 600 gets over the gutter 530 supplied for further processing.

In 3 the general sequence of a control according to the invention is shown. The plant described above for refining and / or melting glass forms a controlled system. The controlled variables, process variables and, if applicable, manipulated variables can be recorded at different locations of the controlled system. For this purpose, the controlled system with at least one measuring device 13 Mistake. The measuring device 13 may be a compensation device 14 be preceded to eliminate external influences.

The of the measuring device 13 Certain sizes are used by detection devices 10 . 11 . 12 added. With a detection device 10 Controlled variables, ie setpoints, are recorded. With another detection device 11 Process variables are recorded in a processing device 21 processed and then by means of an output device 31 can be issued. In another detection device 12 can directly detect manipulated variables in a processing device 22 further processed and via an output device 32 be issued.

The control device according to the invention 1 includes a control device at a high level 50 , as well as a low level controller 60 , The acquired setpoints and actual values are in a linking device 70 linked together via the control circuit levels. The high-level control device 50 In this case, the desired and actual values can be supplied in such a way that in the control device 50 Manipulated variables are determined, which via a default device 55 can be issued. The high-level control device 50 further includes another default device 56 , wherein by means of the default device 56 from the to the high level control device 50 forwarded setpoints and actual values Setpoints for a low-level control device 60 be passed on. From setpoints and actual values, which the control device at low level 60 from the linking device 70 receives and / or from setpoints, which the control device at low level 60 from the high-level control device 50 via the default facility 56 receives are in the low-level control device 60 Control values determined.

The control device 1 further comprises an input device 95 , About the input device 95 Process objectives can be entered in the archiving facility 90 get saved. Depending on the process objectives, setpoints and parameters for the control devices can also be made available by the archiving device. In addition to the, as described above, detected setpoints are in the linking device 70 also archived setpoints from the archiving facility 90 processed. The parameters used in the control devices 50 and 60 the control device 1 be used, these control devices 50 and 60 from the archiving device 90 depending on the input device 95 provided process target.

In the control device, manipulated variables from detected and / or archived setpoint values or actual values are thus determined in different ways, depending on the respective requirements. The manipulated variables are determined by means of an adjustment device 80 in the components of the plant for melting and / or refining glass 2 fed back.

The control according to the invention can be used in different processes. Hereinafter important aspects of a process according to the invention are presented, before going into detail on various embodiments becomes.

Already in the design of a vacuum clarifier plant must be assessed to what extent a significant reduction of the residual gas content in addition to Elimination of the bubbles should be achieved. Is a greater reduction the residual gas content desired, it will be preferable to seek a separation of the process steps. As a general guideline serves the idea that the molten glass preferably should not be converted into foam or precursors thereof. Otherwise is the repatriation of Foam in a homogeneous melt very time consuming. Also, the glass surface should be preferably be little covered with foam to facilitate gas exchange at the glass surface. It should also be noted that the lowest atmospheric pressure by the vapor pressure the most fleeting Glass component is determined. In general, therefore, one becomes the Pressure at approx. 1500 ° C For example, do not lower significantly below 100 mbar.

One of the most important design parameters is the pressure-time curve p (t), which is traversed by a volume element of the molten glass. The time t to reach the residual pressure p _R on a Druckabsenkstrecke 1 is given by a throughput ṁ a cross-sectional area A and the density ρ of the melt

During this time, the air pressure is lowered from the atmospheric pressure p _A to the residual pressure p _R.

The pressure-time curve should be adjusted so that no foam is formed in the volume of the supply pipe on the way to the residual pressure. For this purpose, at given mass flow rate ṁ the length of the pressure drop section 1 and / or the cross-sectional area A are increased. In addition, care must be taken in the unit part, which serves to eliminate bubbles, that no new bubbles are generated, but only the existing bubbles are enlarged and these can easily escape from the melt.

• – Volumendichte der Blasen
• – Größenverteilung der Blasen
• – Zusammensetzung der Blasen
• – Konzentration bzw. Partialdrücke der in der Schmelze gelösten Gase
• – Konzentration des Läutermittels
• – Temperatur des Glases
• – Viskosität des Glases
• – Durchsatz
• – zeitlicher Verlauf des Druckabfalls.

The following state variables should be measured or known at the inlet of the glass into a refining aggregate, in particular into a vacuum-pressure aggregate:

• - Volume density of the bubbles
• - Size distribution of the bubbles
• - Composition of the bubbles
• - Concentration or partial pressures of dissolved gases in the melt
• - Concentration of the refining agent
• - temperature of the glass
• - Viscosity of the glass
• - Throughput
• - time course of the pressure drop.

At the Entry into a vacuum pressure system the bubble density must be within certain ranges: is the bubble density too high, there is a risk of foaming in the Riser. On the other hand, the bubble density must not be too low, otherwise no appreciable degassing can be achieved.

When passing through the glass by a Unterdruckerzeugaggregat reduced over time, the ambient pressure to the set residual pressure (vacuum), wherein the existing bubbles in the melt can be greatly inflated. The bubble enlargement f as the ratio of the initial radius r _A to the final radius r _R at the residual pressure p _R is given by

r_A:

Anfangsradius

r_R:

Endradius

f:

Blasenvergrößerung

die durch die isotherme Vergrößerung

Where:

r _A :

initial radius

r _R :

end radius

f:

bladder augmentation

by the isothermal enlargement

f_BM:

isotherme Vergrößerung

p_A:

Atmosphärendruck

p_R:

Restdruck

und durch die im allgemeinen wesentlich wichtigere Vergrößerung f_Diff » f_BM durch Diffusion von Gasen aus der Schmelze. Je nach Betrag der oben eingeführten Variablen, insbesondere aber bei zu hoher Blasendichte und Temperatur bzw. bei niedriger Viskosität, kann die Blasenvergrößerung so stark sein, dass die Schmelze in eine schaumartige Struktur umgewandelt werden kann. Außerdem wird durch eine geringe Viskosität die Blasenneubildung erleichtert. Dieser im allgemeinen unerwünschte Zustand kann bei einer gegebenen Aggregatform dadurch kontrolliert werden, dass man den Durchsatz oder die Glastemperatur absenkt.Where:

f _BM :

isothermal magnification

p _A :

atmospheric pressure

p _R :

residual pressure

and by the generally much more important magnification f _Diff »f _BM by diffusion of gases from the melt. Depending on the amount of the variables introduced above, but especially if the bubble density and temperature or low viscosity are too high, the bubble enlargement can be so strong that the melt can be converted into a foam-like structure. In addition, the new blistering is facilitated by a low viscosity. This generally undesirable condition can be controlled for a given aggregate form by lowering the throughput or glass transition temperature.

• – Restdruck der Atmosphäre
• – Glasbadtiefe
• – Schaumhöhe
• – Temperatur des Glases
• – Viskosität des Glases
• – Rate verdampfender Glasbestandteil

The following parameters must be measured or known in the vacuum pressure generator:

• - residual pressure of the atmosphere
• - Glass bath depth
• - foam height
• - temperature of the glass
• - Viscosity of the glass
• - Rate vaporizing glass component

There depending on glass type, temperature and negative pressure only a limited number of bubbles the glass surface can leave sufficiently quickly, foam can form. Especially the gas reduction process needs to be regulated that the foam generation rate and the foam destruction rate to preferably low and stable foam heights leads. For accelerated foam degradation can be an additional heating of the foam useful be. this leads to because of the viscosity reduction to an accelerated running of the glass back to the Glasbadoberfläche, as well to an increased Evaporation of the thin Glass films, which promotes their bursting. Additionally, other substances may be added to the rest Increase the Evaporation - connected with an increase the surface tension - used become. Through sensors can Foam thickness, shape and location of the foam cover are detected.

• – Volumendichte der Blasen
• – Konzentration und/oder Partialdruck der Gase in der Glasschmelze.

The following quantities must be measured or known at the outlet of the glass from the vacuum-pressure aggregate:

• - Volume density of the bubbles
• - concentration and / or partial pressure of the gases in the molten glass.

der totale Druck der gelösten Gase in der Schmelze sind. Statt des totalen Drucks kann auch der Partialdruck p_i einer kritischen Gaskomponente verwendet werden.These variables are used as actual values for determining the global quality function f _M and compared with the desired value f _{M, F.} Both sizes are defined as follows: f = a * N + b * p dead Equation 9 where a and b glass type and process-dependent weighting factors and N the bubble density and

are the total pressure of the dissolved gases in the melt. Instead of the total pressure, the partial pressure p _{i of} a critical gas component can also be used.

By phenomenological and / or empirical models as well as partially model-based Regulations and combinations thereof will achieve that the volume density the bubbles and, if necessary, the concentration of dissolved gases at the end of the refining aggregate remains below product-specific pre-determined values.

to Recording process data requires sensors. These include Determination of the mixed moisture hygrometer and IR spectrometer, for Measuring temperature thermocouples and pyrometers, for determining the volume flow through the tuyeres rotameter or massflow controller or pressure transmitter. The viscosity of the glass can be determined by means of oscillating rod or by resonance method (company Marimex) be determined. For determining the redox potential of the glass an oxygen partial pressure probe are used, which also can determine the oxygen partial pressure in the exhaust gas. For the determination the oxygen partial pressure in the exhaust also comes a laser spectrometer Company Bernd, in question. The mixed situation and mixture form can by Capture with one or more cameras with attached image analysis (for example through a system of the company STG, Cottbus) be determined. By means of a bar train with image analysis can the bubble number of the glass are determined. The glass stand can with a platinum contactor whistle by means of a laser over a electrical contact or radioactively determined. The foam height can also over a platinum contactor pipe and determined by means of a CCD camera become. The shape and location of the foam are the same as determined by the shape and location of the batch. The throughput of the Glass results from an integral of the insert or the glass drain. For measuring the negative pressure, a pressure cell with transmitter can be used become.

The Heating power leaves over a transducer for electrical quantities, in particular measure voltage, current, power or frequency. Pressure and flow rate of the protective gas can be via a Determine pressure transmitter or massflow controller. The stirrer speed can be determined by means of a tachometer.

Also the oxygen partial pressure on precious metal components must be determined become. This is done with a per se known oxygen partial pressure sensor (pO2 sensor, measurement measured for example by voltammetry.

Around to perform the process stably and the number of bubbles in the product safely below a certain Holding limit is the capture of at least one of the Table 1 listed Input variables for the multiple Input Multiple Output Model (MIMO Model) required The in table 1 abbreviation used SW means melting tank. The abbreviation LW is the term refining tub abbreviated. UD means vacuum unit, with LK is the term refining chamber meant. The redox ratio gives the concentration of trivalent and / or pentavalent Ions, in particular of trivalent and / or pentavalent ions from lautering auxiliaries such as arsenic and antimony, in relation to the concentration Oxygen on. The term barge is understood to mean a device the making of glass rods by pulling from the melt allows.

Table 1: Inputs for the MIMO model and sensors for their measurement. The abbreviations used in the table Designate: SW melting tank, LW refining tank, UD vacuum unit, LK Läuterkammer.

The The scheme should have at least one of the sizes listed in Table 2.

Table 2: Controlled variables and Corresponding actuators with explanation of the manipulated variable. The Abbreviations used in the table Designate: SW melting tank, LW refining tank, UD vacuum unit, LK Läuterkammer.

The Abbreviation used in Table 2 SAR means melting aggregate, with the abbreviation EZH becomes an electrical Additional heating called. The term feeder becomes a Device understood, which is in the direction of passage of the glass located at the end of the melting or refining tank. The feeder comprises an outer boundary, which can be designed as a cylinder. Inside the feeder Can the glass through a feeder needle from the Schmelzbeziehungsweise refining tank promoted become. The feeder settings essentially comprise the setting the temperature and the stroke of the feeder needle.

The loop is linked using at least one of the following strategies:
PID, fuzzy, neural networks, adaptive control and model-based control strategies such as in particular MIMO control.

Based on the following embodiments, the use of the inventive control for the regulation of the bubble growth, the control of the degassing, the regulation of the glass level and the furnace pressure in a vacuum pressure unit, the regulation of the foam height and structure, and the regulation of the number of bubbles.

aim in the regulation of bubble growth, it is to remove all bubbles. To do this the bubbles have a relatively high buoyancy velocity relative obtained to the surrounding glass melt. The buoyancy speed is given by equation 1. By increasing the temperature increases the partial pressure of a gas in the melt, which consists of one of Glass melt added refining agent can be released. Further, the viscosity of the melt at a temperature increase reduced. Because of the partial pressure difference, this diffuses fining into existing bubbles. This will increase their diameter, which according to Stokesschen Law (Equation 1) leads to an increased bubble ascent rate.

The Same leaves achieve, if instead of or in addition to a temperature change the atmospheric Residual pressure in the refining unit lowers. This will be the total pressure and also the partial pressures the gases contained therein, which in turn because of the Pressure difference between bubbles and the surrounding melt leads to a bladder enlargement.

The Bubble growth rate can be as a function of temperature and / or the atmospheric Residual pressure or measured from the material data, in particular the solubility, the diffusion coefficient and the concentrations.

In 4 the spatial conditions of a refining unit are outlined. If one knows the average start bubble radius in front of the refining aggregate, one can calculate from the known data for the size growth, after which time t ₁ the bubbles have reached a certain size. This time must correspond approximately to the time t that the bubbles reach due to the flow velocity of the glass vs and its buoyancy velocity v _A ,

The average flow velocity vs is given by known pipe cross-section A and a flow rate dV / dt assuming a piston flow through

After passing through the vertical distance of height h, the bubbles must have become so large that they can safely leave the melt on the horizontal distance L with the glass height d due to their buoyancy (cf. 4 ). This means that the maximum bubble rise time t _max in the horizontal fining part must be smaller than the average cycle time t _L. It can thus be estimated how many bubbles reach the surface of the glass bath, where they burst open and leave the melt.

in the In connection with the bubble growth, it should be noted that to carry out the Purification that Bubble growth must be kept within certain limits. If the bubble growth is too small, because of too small Buoyancy rate not enough bubbles from the melt be removed. If the bubble growth on the other hand is too large, there is the risk that the proportion of bubbles per unit volume of the melt gets too big. As a result, the effective density of the melt is reduced too much, which to an undesirable Influencing the convection flow in the melting and refining area, as well as the demolition of the glass column lead in the vacuum part can.

One too high a bubble content per unit volume of the melt leads to a Reversal of the proportion of glass to gas in the sense that foam in various forms can arise. This is an undesirable operating condition since the repatriation of Foam in glass is very time consuming, and the amount of foam only with Help of physical or chemical methods again reduced can be. In particular, the heating is used to increase the Evaporation or injection of surface tension increasing substances in question. Foaming is also negatively affected if too little residual pressure causes a new blister formation.

The following are the main manipulated variables for influencing the bubble density after the refining unit Sizes available: the length L of the refining section with fixed cross-sectional area, the volume flow of the glass dV / dt and the residual atmospheric pressure in the refining unit. In addition, the bubble growth and buoyancy rate of the bubbles can be controlled by adding refining agent and adjusting the temperature. Furthermore, to control the bubble growth, it is necessary to at least approximately investigate the size distribution and the volume density of the incoming bubbles as well as the content of the gases dissolved in the melt.

In addition to the elimination of the bubbles, the proportion of dissolved gases in the melt should be significantly reduced. This purpose is the regulation of degassing. The mass flow dm / dt between the bubbles present in the melt and their surroundings is proportional to

Denoted therein r _{B is} the mean bubble radius, N _{B is} the bubble density, D _i (T) is the diffusion coefficient, Δp _{i is} the partial pressure difference between bubbles and surrounding melt for the gas i and Δt is the duration of the action.

you recognizes in Equation 13 that the extracted gas amount Δm becomes higher, the longer the process takes the higher the internal exchange surface the bubbles (bubble density and surface area) is, the greater the pressure difference and the higher the temperature is higher as the diffusion coefficient increases Temperature also rises. These are the most important ones Manipulated variables for Regulation of degassing.

By default, though the starting bubbles are not easily influenced. As for the scheme the bubble growth is thus also for the regulation of degassing required, the size distribution and the volume density of the incoming bubbles and the content of the dissolved in the melt Gases at least approximately to know. For this purpose, the melt, as mentioned above, regularly samples taken and the content of dissolved Gases as well as the bubbles examined.

In another embodiment can however, the number and size distribution the starting bubbles are affected: this is the temperature in Melting range specifically varied. Another, independent possibility is in front of or at the entrance of the glass in the refining aggregate targeted bubbles in a certain size distribution and density produce. This can be done, for example, by passing through fine nozzles pulsed glass injected into melt.

A different possibility is the targeted exploitation of electrochemical reactions, for example on platinum, which are known from the literature.

There the bubbles are removed from the process is the time for size growth the bubbles are limited. This leaves as largely independent control variables for the control the degassing especially the starting bubble density and the mean bubble radius.

The following embodiment describes the regulation of the glass level and the furnace pressure in one Unterdruckläuteraggregat.

The Height of Glass stand in a vacuum pressure unit with vacuum part results from the density of the glass, the height of the refining bank and in the Läuterteil set atmospheric Residual pressure.

• – der Absolutdruck in dem Läuteraggregat
• – der Differenzdruck zwischen Luftdruck und dem Druck im Läuteraggregat, oder
• – der Glasstand im Läuteraggregat.

A predetermined pressure difference can be regulated, for example, in the following way: as control variables for the furnace pressure in a vacuum-pressure generator, it is possible to use:

• - The absolute pressure in the refining unit
• - the differential pressure between air pressure and the pressure in the refining aggregate, or
• - The glass stand in the refining unit.

This are also examples of Controls that are performed in a low-level controller can.

According to 5 is measured with a pressure sensor, the absolute pressure in the Unterdruckzählaggregat. A signal converter sends this signal to a controller with a fixed setpoint. The controller controls a control valve, which regulates the inflow of false air and thus a so-called tes forms controllable leak.

Unlike in 5 shown absolute pressure control is with a differential pressure control according to 6 controlled by a differential pressure measurement of the differential pressure between the Unterdruckzigeraggregat and the outer atmosphere. A signal converter sends this signal to a controller with a fixed setpoint. The controller controls a control valve, which regulates the inflow of false air and thus forms a controllable leak. The absolute pressure control and the differential pressure control therefore differ only in the type of measuring device used 13 , which is formed in the discussed embodiment as a pressure sensor.

In the glass level control, as in 7 represented, measured with a glass level sensor, the glass level in the Unterdruckzählaggregat. A signal converter sends this signal to a controller with a fixed setpoint. The controller controls a control valve that regulates the inflow of false air (adjustable leak). The varying pressure in the Unterdruckzählaggregat leads due to the hydrostatic pressure to a varying glass level. Therefore, the glass level control is connected to the pressure control, which as stated above, can be designed as absolute pressure or differential pressure control.

The Differential pressure or absolute pressure control can also be used for the control the furnace pressure are used: for the purification in aggregates at normal pressure is the atmospheric Pressure in the refining chamber relevant. This results from the weather-dependent pressure of the ambient atmosphere, the fed through the burner Gas quantity, the discharged Amount of exhaust gas and by the leak rate. At the same time, the partial pressures the gases in the furnace atmosphere by setting a balance of the amount of gas supplied and discharged kept stable. The basic version of the regulation of pressure in the oven is carried out with differential pressure or absolute pressure regulators.

Control of the foam height

The foam height in the refining chamber can by mechanical sensors, by a thickness measurement with radionuclides or by interaction with electromagnetic or acoustic Waves are detected.

By Introduction of chemical substances, of thermal energy, pressure change or mechanical agitation, the foam decomposition rate can be varied become.

For example, the following strategy is used to control the number of bubbles in the case of vacuum refilling: a predetermined temperature profile is maintained by means of the heating power of various burners via a MIMO temperature controller. An independent control circuit regulates the glass level and furnace pressure in the refining chamber via adjustments to the height of the refining bench and the suction power of the vacuum pump. The setpoints for glass level, furnace pressure and the temperature profile to be set are determined from a higher-level control loop. The higher-level control loop calculates the setpoint values for the subordinate control loops from the currently measured number of bubbles and a corresponding setpoint, as described in 8th is illustrated.

In the case of in 9 As shown in the scheme for high-frequency refining, both upper furnace burners and the electric power of the coil are available as energy sources. Both energy inputs affect the temperatures in the glass bath and in the upper furnace. For the control of a desired temperature profile in vaults and melt, therefore, a MIMO regulator is necessary, which calculates the required performance of the burner and the coil. The setpoint values for the temperature profile can in turn be obtained from a superordinate control loop which regulates the bubble number or another quality variable of the glass.

Claims (42)

Regulating device ( 1 ) for a plant ( 2 ) for melting and / or refining glass with regulating devices ( 50 . 60 ), which form at least two control circuit levels, characterized in that the control device ( 1 ) a linking device ( 70 ), which can link a multiplicity of desired values and / or actual values over a plurality of control circuit levels, - wherein the control circuit levels are hierarchically arranged and the at least one control device ( 50 ) of the superior control circuit level a first default device ( 56 ), with which of the at least one control device ( 60 ) the subordinate control circuit level setpoints can be specified, wherein the control device ( 1 ) a first detection device ( 10 ) for detecting at least one superordinate controlled variable of the following control variables for controlling the glass quality: - volumetric number of bubbles number - bubble size distribution - content of the gases dissolved in the glass melt, and - wherein the control device ( 1 ) a second detection device ( 11 ) for detecting at least one subordinate controlled variable of the following process variables: - temperature - atmospheric residual pressure in the refining chamber - heating power - heating power in upstream and / or downstream process steps - moisture content - mixed batch - mixture form - volume flow through the tuyeres - glass level in the melting tank and / or in the lauter tub and / or in the gutter and / or in the agitating crucible - Viscosity of the glass - Throughput of the glass - Oxygen partial pressure of the glass - Water content of the glass - Oxygen partial pressure of the exhaust gas - Oven pressure in the melting tank - Foam height - Shape of the foam - Location of the foam - Pressure and / or flow rate of the protective gas - Blistering rate in the melting tank - Stirrer speed - Partial oxygen pressure on precious metal components. Regulating device ( 1 ) according to claim 1, characterized in that the linking device ( 70 ) is a multiple input multiple output (MIMO) system. Regulating device ( 1 ) according to claim 1 or 2, characterized in that the at least one control device ( 50 ) of the superordinate control circuit level, a second presetting device ( 55 ), with which directly manipulated variables can be specified. Regulating device ( 1 ) according to one of the preceding claims, characterized by a presetting device, which the first presetting device ( 56 ) for specifying the desired values and the second presetting device ( 55 ) for presetting the manipulated variables. Regulating device ( 1 ) according to one of the preceding claims, characterized by at least one first processing device ( 21 ) in which at least one of the process variables can be processed. Regulating device ( 1 ) according to one of the preceding claims, characterized by at least one first output device ( 31 ), which can output at least one of the process variables. Regulating device ( 1 ) according to one of the preceding claims, characterized in that at least one detection device at least one measuring device ( 13 ) for measuring at least one process variable. Regulating device ( 1 ) according to claim 7, characterized in that the measuring device ( 13 ) can be arranged at at least one of the following: melting tank, floor drains, top furnace, lauter tub, refining chamber, refining crucible, riser, horizontal refining chamber, downpipe, conditioning part, homogenization system, feeder, device for hot forming, cold end. Control device according to one of the preceding claims, characterized by at least one adjusting device ( 80 ) for adjusting at least one manipulated variable. Regulating device ( 1 ) according to claims 9, characterized in that the adjusting device ( 80 ) can be arranged at at least one of the following: melting furnace, top furnace, refining tank, refining chamber, refining crucible, riser, horizontal refining chamber, downpipe, conditioning part, homogenizing system, feeder, device for hot forming. Regulating device ( 1 ) according to one of the preceding claims, characterized by at least one third detection device ( 12 ), in which at least one of the following control variables can be detected: - water addition amount into the mixture - water injection amount in the upper furnace atmosphere - Oxidationsmittelzumischungsmenge for fossil fuels - flow rate through the blast nozzles - ratio between fuel and oxidant - position and / or number of cycles and / or Pause times and / or amount of substance per cycle of the insertion machine - Volume flow and / or composition of the injection of surface-active substances - Power density, which is generated by the foam-destroying energy form - Suction power of the pump - Leak rates - Height of the refining bank - Heating power - Pressure and / or flow rate of the inert gas - Stirrer speed - gas composition on the glass-facing surface of precious metal components Regulating device ( 1 ) according to one of the preceding claims, characterized by at least one second processing device ( 22 ), in which at least one of the manipulated variables can be processed. Regulating device ( 1 ) according to one of the preceding claims, characterized by at least one second output device ( 32 ), which can output at least one of the manipulated variables. Regulating device ( 1 ) according to one of the preceding claims, characterized by a compensation device ( 14 ), which can compensate for the influence of disturbance variables, such as in particular day-night fluctuations, air pressure fluctuations, humidity variations, on the manipulated variables and / or controlled variables. Regulating device ( 1 ) according to one of the preceding claims, characterized by an archiving device ( 90 ), which can archive the setpoint values for the controlled variables and / or the parameters of the control devices. Regulating device ( 1 ) according to one of the preceding claims, characterized by an input device ( 95 ) through which the current production target can be entered. Regulating device ( 1 ) according to one of claims 15 or 16, characterized in that the archiving device ( 90 ) the setpoint values for the control variables and / or the parameters of the control devices ( 50 . 60 ) according to the current production target. Device for melting and / or refining with a regulating device ( 1 ) according to any one of the preceding claims. Contraption ( 1 ) according to claim 18, characterized in that the plant ( 2 ) for melting and / or refining glass at least one insertion machine, at least one melting tank, at least one top furnace, at least one refining tank, at least one refining chamber, at least one refining crucible, at least one riser pipe, at least one horizontal refining chamber, at least one downpipe, at least one conditioning part, at least one device for injecting surface-active substances, at least one device for introducing inert gas, at least one homogenization system, at least one feeder, at least one device for hot forming, at least one cold end, at least one blowing nozzle, at least one pump and at least one stirrer. Vacuum melting and / or annealing unit with a control device ( 1 ) according to one of claims 1 to 17. High-frequency heatable melting and / or refining plant with a control device ( 1 ) according to one of claims 1 to 17. Directly electrically heatable melting and / or refining plant with a control device ( 1 ) according to one of claims 1 to 17. Method for regulating an installation ( 2 ) for melting and / or refining glass, comprising the following method steps: detecting at least one controlled variable, detecting at least one process variable corresponding to the controlled variable, determining at least one manipulated variable for controlling the process variable, characterized in that the glass quality depending on the type of glass and or is controlled by the plant for melting and / or refining glass as a function of at least one of the following parameters in a control system with hierarchical control circuit levels: - volumetric number of bubbles density - bubble size distribution - content of gases dissolved in the molten glass, wherein at least one control variable in a control system is determined, which comprises at least two control circuit levels, wherein the higher-level control circuit level specifies the target values to the subordinate control circuit levels and these parameters form the higher-order controlled variable of the superordinate control circuit level. Method according to claim 23, characterized that one Variety of setpoints and actual values over several control loop levels linked together become. Method according to claim 23 or 24, characterized that the Control using a MIMO (multiple input multiple output) algorithm carried out becomes. Method according to one of claims 23 to 25, further characterized by the following method steps: detecting at least one controlled variable which can be used as detected setpoint, detecting at least one process variable, processing the process variable, outputting the processed process variable as actual value, linking detected setpoint values and actual values via Control loop levels, passing the setpoint values to a control device ( 50 ) at high control circuit level, predetermining the setpoint values by a control device ( 50 ) at a higher control loop level to a control device ( 60 ) at a lower control loop level, transfer of the actual values to the control device ( 60 ) at a lower control circuit level, determining a manipulated variable from the setpoint values and actual values in the control device ( 60 ) at a lower control circuit level output the control variable to a setting device ( 80 ) Setting the manipulated variable in the process. Method according to claim 26, characterized in that that stored Setpoints available which are also with actual values over control circuit levels connected become. Method according to Claim 27, characterized that the stored setpoints correspond to the process target. Method according to one of Claims 26 to 28, characterized in that manipulated variables are generated directly by a control device ( 50 ) of the superordinate control circuit level for setting. Method according to one of Claims 26 to 29, characterized that at least a manipulated variable is detected, which is processed and for the setting is output as processed manipulated variable. Method according to one of claims 23 to 30, characterized in that the operating behavior of the system ( 2 ) for melting and / or refining glass by simulation calculations and / or is simulated. Method according to one of claims 23 to 31, characterized that this Result of the simulation for determining the control behavior at least a process level is used. Method according to one of claims 23 to 32, characterized that for at least a process level from the result of the simulation for determining derived from the control behavior a model for control in real time becomes. Method according to one of Claims 23 to 33, characterized in that the result of the simulation for determining the control behavior of the entire system ( 2 ) is used for melting and / or refining glass. Method according to one of Claims 23 to 34, characterized that to Determining the at least one manipulated variable from the at least one Setpoint and the at least one actual value an empirically developed Regulation is applied. Method according to one of claims 23 to 35, characterized that to Determining the at least one manipulated variable from the at least one Setpoint and the at least one actual value one on a phenomenological Model-based regulation is applied. Method according to one of claims 23 to 36, characterized that to Determining the at least one manipulated variable from the at least one Setpoint and the at least one actual value one on a chemical and / or physical model-based prescription becomes. Method according to one of Claims 23 to 37, characterized that to Determining the at least one manipulated variable from the at least one Setpoint and the at least one actual value, a rule applied which is a combination of an empirically developed Regulation and / or one based on a phenomenological model Regulation and / or on a chemical and / or physical model, is developed. Method according to one of claims 23 to 38, characterized. in that in For each control loop, the parameters of the regulations for determining at least one manipulated variable based a comparison with the process data adapted to the current circumstances. Method according to claim 39, characterized that the for the Comparison used process data derived from current production. Method according to claim 40, characterized in that that the for the Comparison used process data be determined in experiments. Method according to one of claims 23 to 41, characterized that beside the glass quality of Change of production parameters is regulated.