초록

The invention relates to a method for changing glass compositions in continuously operated melting installations which has a significantly shortened melt changeover time and therefore lower costs and in which the glass quality is not adversely affected.

대표청구항 ▼

We claim: 1. Method for changing glass compositions in continuously operated melting installations, comprising the following steps: a) a number of mobile melting-down units are made available which correspond to the number of glasses to be produced with the glass composition desired in each case, k

We claim: 1. Method for changing glass compositions in continuously operated melting installations, comprising the following steps: a) a number of mobile melting-down units are made available which correspond to the number of glasses to be produced with the glass composition desired in each case, known as the target glasses, which melting-down units are provided with coupling devices so that they can be connected to and disconnected from the melting installation, the melting-down units, after use, still having glass residues comprising the target glass in question, which is available once again for the next melting process with the same or a similar target glass; b) the melting-down unit which has been selected in each case is used as part of the melting installation, the coupling devices of the melting-down unit being connected to those of the melting installation, in order to be able to carry out glass-melting operation and vessel-wall cooling, and a glass overflow is formed into a further processing system; c) the contents of the melting-down unit which has been fitted into the melting installation are locally preheated in order to create a region of sufficient glass conductivity, in which electrical energy can be introduced; d) the glass-melting operation with electrical energy being introduced is commenced with vessel-wall cooling taking place at the same time; e) the contents of the melting-down unit are supplemented by a batch having the composition of the target glass, and the glass-melting operation in accordance with step d) is continued in order to produce target glass and in order to feed this target glass to the further-processing system; t) after the further-processing system has been brought to operating temperature, glass residues which are of a different type than the target glass, if any such residues are present, are displaced on an ongoing basis in the further processing system by the target glass supplied, until the target glass is produced with a sufficiently pure, composition. 2. The method as claimed in claim 1, wherein in step c) a gas burner is used to produce a molten pool as local conductivity region in the glass of the melting-down unit. 3. The method as claimed in claim 1, wherein in step d) high-frequency electrical energy is supplied, this energy being introduced into the local conductivity region, heating and increasing the size of the latter until the entire contents of the melting-down unit, apart from in the cooled vessel-wall region, has been melted. 4. The method as claimed in claim 1, wherein a flying change is performed between molten starting glass and cold target glass, the melting-down unit holding the starting glass, after it has been emptied as far as possible, being connected to a mobile vessel wall cooling means, in order to be transported with the latter to a cooling site, while the melting-down unit holding the target glass is introduced into the melting installation at the vacated location. 5. A melting installation, comprising: at least one melting-down unit; central coolant circuits; means for feeding the melting-down unit with glass constituents of the desired composition which are to be melted; and a further-processing system for treating the melted glass, wherein the central coolant circuits have stationary connection locations for the coolant feed and for the coolant return, a number of skull crucibles are provided as mobile melting-down units, these crucibles each having connection locations which are carried with them for coolant feed and coolant return, and wherein the stationary connection locations and the connection locations which are carried along belonging to one of the skull crucibles cooperate with one another to act as coupling devices, in order to complete the coolant circuit when the skull crucible is introduced into the melting installation. 6. The melting installation for carrying out the method as claimed in claim 5, wherein the coupling devices comprise connections for flexible lines, which are used to circulate cooling media after the skull crucible in question has been disconnected from the stationary melting installation during the transporting and storage of the skull crucible in question. 7. The melting installation for carrying out the method as claimed in claim 5, wherein the coupling devices comprise electrical plug-connection features for a high-frequency coil of the skull crucible. 8. The melting installation for carrying out the method as claimed in claim 5, wherein the coupling devices comprise electrical plug-connection features for temperature sensors of the skull crucible. 9. The melting installation for carrying out the method as claimed in claim 5, wherein the coupling devices comprise quick-fit clamping connections for bubbling gas. 10. The melting installation for carrying out the method as claimed in claim 5, wherein the coupling devices are arranged on a lower part of the skull crucible in question, which interacts in the manner of a plug connector with at least one crucible-receiving location of the stationary melting installation. 11. The melting installation for carlying out the method as claimed in claim 5, wherein the skull crucible has a mating flange and a clamping device in order to enable a flange of a connected unit to be clamped securely in place and to enable the clamping to be released when the skull crucible is being changed. 12. The melting installation for carrying out the method as claimed in claim 10, wherein a mounting location and dismantling location for the skull crucible is provided next to the crucible-receiving location, being connected to one another via a displacement unit in order for the skull crucible in question to be displaced from one location to the other.