DE903856C - Device for melting powdery or grainy substances - Google Patents

Description

Device for melting powdery or granular substances for production bubble-free melting of sand, quartz powder or the like. there are different procedures known. The most effective: means i, st the melting at high negative pressure and high tempera ruins, dia, then @diie gas inclusions or those during melting Additionally released gases have the largest volume and are relatively light get out of the barely tenacious bath. It has been difficult so far, that way To bring melted goods back to normal pressure ratios. Either the furnace operation had to be interrupted for the purpose of: So d! iskon @ tin: uierl: I will be geared, or it was Auslewsungsanlage.n necessary. The latter are, however, in the presence of large Teml4erabur and large pressure differences structurally difficult and expensive.

Processes are also known which are the most commonly used heating of the melts Replace with hot gases with electrical heating. But this was hardly Care was taken to ensure that one part of the required, relatively large Electric energy can be saved if you take the appropriate direction Forces heat flow in the melt and if you especially heat radiation losses to the outside.

To remedy the existing deficiencies, this will be a new design Melting furnace as well as means for a rational electrical heating of this Furnace specified. The "'#, usschleu.sen becomes very easy when you consider the weight of a used a few meter high column of melted and half-melted good, in order to overcome the counter-pressure of the atmosphere completely or for the most part. Therefore is sent to the crucible, in which the melt flow that has not yet been completed is reached need to be connected to a downpipe that is electrically heated: is-. In its bottom end the clearest and best network flow is obtained, which if necessary even as a conductor for edenelectric: electricity can be used.

Because the flow of the gases to be sucked off in this pipe is constantly upwards is directed, the crucible and the downpipe practically constitute a countercurrent heat exchanger represents that the heat of the electrical heating favorably on the half-melted and transfers the feed material newly introduced from above. Unnecessary heat loss are also .noch avoided that said downpipe is concentric and is surrounded with a sufficiently large distance with a cylindrically shaped housing, the Inner wall is polished metallic bright and thus the heat rays in the direction of Long axis reflected. The metal parts of this housing can also be used as electrical Ladder to be used with. The intermediate space can contain and / or contain protective gas Un @ te: be held rd-jerk.

Wila one annoying: avoid large height of the downpipe., So you have to create a correspondingly large underpressure in the lower outlet area of the downpipe as well as a Schleusie od. Ügl. for the discharge of the finished product. At this Lock, however, the difficulties are no longer as great as those mentioned above, because the pressure and temperature differences to the outside are no longer so great.

The drawing shows .the basic process of bubble-free Melting down, whereby gases from the melting interface through the not yet melted Contents can escape through and are completely sucked off. 'She provides one Furnace for continuous operation with good drainage of the melting material, against Serve ,, tnnospheric pressure dlwrch lein Fal.l, pipe.

The crucible i heaps into a vertical downpipe 5 and is with this suspended in the vertical housing 2., the space between the crucible @ fiallrolhr and the housing -with the roughness 4. is connected above this low gel., which is constantly connected to the vacuum pump VP. Via the faucet lock 6 is continuous! granular feed material 3 in, the crucible i introduced, while the Seh.melzflussdurch the downpipe 5 due to its weight against any possible: negative pressure in the processing crucible 7 in. This one runs out. Room 7 will! with a contradiction in heating in the glass, se even kept at a higher temperature. One can also use the downspout as an electrode use for the well-known resistance heating of the outflowing jet, the crucible 7 forming the other electrode.

Des, downpipe is expediently designed as a Wi.dorstandskörper, its return is useful to reduce the inductive loop effect inside the boiler or through the metal hatchets on its wall (Pfeilre I). The lower end of the feed line of the downpipe can be protected from a protective gas in a known manner Way around and be provided with a nozzle piece for pipe production: The inner wall of 2 is conveniently a mirror! for thermal radiation reflection.

Compared to the gas melting, the get heat losses as a result the one for the melting process is not. more exploitable! Avoided exhaust fumes.

That. Processes and procedures for this are made easier and cheaper the production of bubble-free, vitreous or crystallizing melts. It is particularly suitable for optically ie glasses and is ideal for increased use of the little cooling-sensitive quartz glass and similar glasses, during use on the fiberglass production from the melt flow results in the removal of fibers greater strength by reducing the number of imperfections.

Claims (1)

PATENT CLAIMS: e.g. Device for melting powdery or granular ones Substances, e.g. B. Quarzsiandi, where the Nied @ melt, z by electric heating takes place under ventilation, characterized by an idias Schmelegut absorbing Downpipe (5), through the one if necessary; constant removal of the melted Good is made possible from the furnace container without breaking the vacuum. a. Facility Make claim i, characterized in that the removal of the molten goods to reduce the size of the felling pipe in a container (7) with a gas negative pressure he follows. 3.. Device according to claims i and 2, characterized in that " the downpipe (5) is designed as a heating conductor and in a housing (2) in protective gas or vacuum is disordered, where the housing may be more concentric Rear body serves and is nut-clad with a heat mirror. 4. Set up after the claims (i- to 3, characterized in that the downpipe (5) at the entrance (i) is widened in the shape of a taper or funnel ..