AGITATOR FOR FUSIONLIQUID GLASS

The invention concerns the constructional structure of agitators for fusionliquid glass, preferably for the homogenization of Glasschmelzen in higher temperature ranges.

Agitators for the homogenization of Glasschmelzen are in different execution variants in the glass industry admit and in use. Temporal as well as qualitative homogenisation success is essentially by the constructional structure of the agitators and certain the contact material by the materials, essentially to the glass. With easy-melting and little aggressive glass ones simple Blattund screw agitator from high-quality fireproof materials is well-known, which obtained however one nich sufficient homogenization, short service lives besa&szlig in the construction; EN and by the high material abrasion constantly to unwanted glass errors led. Agitators out hitzeund steel resistant to scaling could be able and only in limited cases to be used, since these kinds of steel lead partially to the discoloration and blistering of the glass and are a little steady to aggressive Glasbesdandteilen. Therefore agitators, which possess a material of the group of precious metals as glass contact material, for nearly all technical types of glass worked satisfactorily and become as admit in the strengthened Maß e successfully assigned.

In a set of godfather writings the structure of well-known agitator constructions for the homogenization of Glasschmelzen is descriptive.

In the DE-A-43 26,143 is represented, daß the agitator or plunger from a molybdenum core as well as a ceramic(s) body and a coat from platinum exists. The DE-A-19 16,817 indicates, daß the pores of the refractory material with one against molybdenum, which refractory material and platinum inert gas are filled. In the DE-A-25 00,793 the structure is particularly described the shank range of a molybdenum agitator, which is surrounded by a platinum pipe and whose gap of an inert gas flowed through.

The agitator after the patent DD-C-203 899 consists of a molybdenum part diving in into the glass and a shank of a heatproof steel. The shank is inside hollow and with air cooled.

All these agitators are composed of different materials and require the supply of an inert gas as protection against oxidation of the molybdenum parts.

The combination of the different materials at high temperature is in practice connected with problems due to different expansions and the oxidation susceptibility of the molybdenum. Also the supply of inert gas or cooling air is trouble-prone at high temperatures.

Unfavorably are au&szlig with these well-known agitators; erdem the high material employment of the pure precious metals and their alloys, which increase the Investkosten substantially, as well as their limited area of application at high temperatures, which lead to the destruction of the agitators. By the use of stabilized and dispersion-solidified precious metals, platinum or platinum/rhodium Legierunge, a crucial employment extension of these agitators is preferably obtained with affordable capital outlays, sufficient life span and good glass quality. From practice, from folder material and the literature (glass-technical reports 65, 1992 No. 4, P. 99 and FF) the employment of feinkornstabilisieitem and dispersion-hardened platinum or appropriate platinum alloys is well-known for the purposes of the glass production. Agitators, plungers or other homogenisation mechanisms for Glasschmelzenn as well as centrifuges or nozzles for the glass fiber production are preferably made of these fine-grain-stabilized dispersion-solidified precious metals or precious metal alloys, particularly platinum or platinum rhodium alloys.

In order to lower immmer still high precious metal portions further, increasingly agitators are well-known, which consist of several layers of different materials and exhibit as glass contact layer a very thin precious metal layer. The basic layer of these well-known agitators preferably consists of molybdenum or tungsten; this precious metal layer is protected by ceramic materials opposite the substrate. Since the Tragermaterialien oxidizes with approx. more than 600 °C, muß the interior of the agitator hermetically locked and evacuated its. From this the disadvantages of these agitators with layer structure result. There the precious metals and/or their alloys are not gas-tight and badly implemented Schweiß the agitator if a penetration of atmospheric oxygen sewed makes possible, the substrate is destroyed in shortest time, a total failure of the agitator is the result. Auß erdem arise through unregelmäß glass error increased ige glass currents. Further is after the Pat. Abstr. OF Japan, C - 354, Abstr. JP 61 - admits 21,923 (A) a stirrer with superstructures as full screw, whereby the Vollstab consists of steel. Centrically upward led, the upper glass layers will become however due to the closed construction of the scrambled egg container with not mixed the glass current. The agitator causes both horizontal and vertically only a partial mixing of the fusionliquid glass. The task of the invention consists of arranging the constructional structure of an agitator for homogenizing fusionliquid glass in high temperature ranges with foundation engineering parts so daß the agitator a small material employment possesses, ausschließ lich from precious metals and/or precious metal craving and at a higher life span a continuously good glass quality exists produced.

Erfindungsgemäß becomes gemä&szlig the task by the agitator; Requirement 1 solved. The basic element of the agitator within that erfindungsgemäß EN stand construction is erfindungsgemä&szlig the cylindric agitator shank, that; is hollow trained. The agitator is erfindungsgemäß thus characterized, daß the hollow agitator shank over the height of cultivations of agitator possesses and on the inside by more zylinderoder flächenförmige agitator shank reinforcements against twists, diving in into the glass bath, is stabilized. Auß erdem the cylindric agitator shank can possess kreuzund/or segmentförmige reinforcements. The cultivations of agitator become erfindungsgemäß in an educated manner by the agitator shank reinforcements through-rising up by agitator shank drillings.

The top of the agitator shank is in such a way arranged, da&szlig after well-known solutions; problem-free and fast changing of the agitator to the agitator drive engine takes place. The lower part of the agitator shank is prefer-proves with an approximate round cap completely locked. For the reaching of good homogenization the fusionliquid glass is mixed by a sufficiently high rotation speed of the turning agitator. The glass in a vertically ascending or vertically descending Flie&szlig becomes simultaneous by the rotating motion of the agitator; direction constantly in its altitude changes. Drehund vertical movements of the glass is reached by the lateral cultivations of agitator to the agitator shank. The number of cultivations of agitator to the agitator shank is limited by their pressure areas and the forces resulting from it to the agitator shank. The agitator possesses a process engineering optimal number of cultivations to the agitator shank with particulars groß EN Scherflächen.

In the simplest case the agitator shank is provided in certain headrooms with opposite drillings, by which cylindric, rounded at both ends locked pipes passed through and with the agitator shank verschweiß t are. From it an agitator with several more zylinderoder flächenförmigen cultivations of agitator, which homogenize the glass, results. An optimal torsional strength of the agitator shank can be achieved by it, daß in certain angles transferred over the entire glass condition height several cylindric agitator shank reinforcements in the interior of the agitator arranged are. At an agitator shank with groß em diameters are fastened small flächenförmige cultivations of agitator to an end of an internal reinforcement and depending upon surface größ ere flächenförmige cultivations of agitator attached at the ends several agitator shank reinforcements. Sufficiently if agitator shank reinforcements over the entire glass condition height are present, then the flächenförmigen cultivations of agitator are fastened to any place of the agitator shank. Auß passing through of flächenförmigen cultivations of agitator is preferably screw-shaped arranged, possible for erdem by the agitator shank. If the diameter of the agitator shank to 90% of the agitating cell diameter amounts to, then the agitator star, more kreuzoder possesses segmentförmige reinforcements or a combination of these reinforcements, which represent together the basic elements of the agitator shank. Those äuß ere outline of the agitator shank for the cultivations of agitator is cylindric. With a preferential Auführung the ends of the segmentförmigen reinforcements are at the same time designed as cultivations of agitator. The ends of the agitator shank reinforcements are designed as cylindric or flächenförmige cultivations of agitator. For highest demands remaining the cavity can be in the agitator shank and in the cross-shaped reinforcements with a ceramic, powdered mass filled out, in the temperature range approx. more the than 800 °C sintered, but although for a constant air interchange is open-porously porous. In addition each Rürhrerschaftversteifung in the agitator shank possesses one or more expansion openings, which ensure a pressure balance during rise in temperature.

The advantage erfindungsgemäß EN of agitator exists in the minimized use of precious metals and precious metal craving due to erfindungsgemäß EN of constructional structure of stand of the agitator. By the use of ausschließ lich precious metals the well-known structure of multi-layer of the agitator from different Metallund ceramic(s) materials is avoided and thus the life span of the agitator is substantially increased.

A repair of defective agitators is easily possible by the simple constructional structure. A complete renewal of individual defective agitator construction units is at short notice and time-saving executable by their exchangeability.

Those erfindungsgemäß EN agitators are to be described on the basis of remark examples more near.

In the figures represent:

Figure 1

- a cut plan view with agitator shank reinforcements and cultivations of agitator

Figure 2

- a side view of the figure 1 with interrupted surfaces förmigen cultivations of agitator

Figure 3

- a side cut of an agitator shank with cylindric cultivations of agitator

Figure 4

- a cut plan view of the figure 3

Figure 5

- a side cut of an agitator shank with cylindric agitator shank reinforcements and flächenförmigen agitator cultivated

Figure 6

- a cut plan view of the figure 5.

The figure 1 shows the cut of an agitator in plan view, whereby the agitator shank 1 consists of four parts and on the inside by four segmentförmige reinforcements 8 is stabilized. The segmentförmigen reinforcements 8 are at the same time trained as flächenförmige cultivations of agitator 6 at their ends. Both by the agitator shank 1 and by the segmentförmigen reinforcements 8 agitator shank drillings 2 are brought in, by which cylindric cultivations of agitator 3 with rounded locked ends 4 obtains an additional reinforcement. Each cylindric agitator shank reinforcement 7 possesses at least one expansion opening 5. the entire cavity within the agitator shank 1 is filled out with a porous frit 9. A side view of an agitator shank 1 is represented in the figure 2. In this execution variant the flächenförmigen cultivations of agitator 6 are differently gro&szlig in their Scherfläche; and differently long and in several levels arranged, so daß around the agitator shank 1 the glass stream is often torn up.

The figure 3 shows a side cut of an agitator shank part. The agitator shank 1 consists of a platinhaltigen cylinder barrel, in which any number of agitator shank drillings shifts 2 is oppositely arranged. In the agitator shank drillings 2 facing in each case cylindric agitator shank reinforcements 7, which change 3 with rounded locked ends 4 into cultivations of agitator, are passed through and to the agitator shank 1 fastened.

In the figure 4, the arrangements of the cylindric cultivations of agitator 3 are to be seen to a cut plan view of the figure 3. Their is represented around 60 ° transferred arrangement on three elevator levels. 7 5 six cultivations of agitator 3. cylindric with expansion openings result from three agitator shank reinforcements.

A further execution variant of an agitator is represented in the figures 5 and 6. In the agitator shank 1, in this case transferred drawn, agitator shank reinforcements 7 are brought in. On the rounded off ends of 10 of two agitator shank reinforcements 7 a flächenförmiger cultivation of agitator 6 is applied. Auß erdem a flächenförmiger cultivation of agitator 6 is shown, which is fastened on a rounded off end of 10 of an agitator shank reinforcement 7 or only on the agitator shank 1.