DE1235527B - Oven for preheating a vitrifiable mixture - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

CZECH

PATENT OFFICE

EDITORIAL

C03b

Int. Cl .:

German class: 32 a -1/00

Number: 1235 527

File number: S 77639 VI b / 32 a

Filing date: January 20, 1962

Open date: March 2, 1967

The invention relates to a furnace for preheating a vitrifiable mixture, in particular one Furnace with a shaft in which the mixture flows in countercurrent to a flow of hot flue gases falls, which emerge from the melting tank arranged below the shaft S. It is already has been proposed to preheat the mixture in a shaft provided with baffles, in which the mixture on the one hand alternately sinks, the same partly from the baffle plates or fully supported, and on the other hand in free fall a small height of a baffle falls down to the other. The heat exchange takes place while the mixture is stored on the baffle plates low, since only the upper layer is in contact with the hot gases. The heating The lower layer of the mixture is restricted by the baffle plates that hold the mixture shield against the hot gases. Only a small part of the gases therefore comes in with the mixture Touch and contributes to the heating of the same to a small extent. Even during the free fall of the As a mixture from one baffle plate to the other, the heat exchange is only central because of the free fall cannot be slowed down by the gases rising in countercurrent and therefore not essential is slowed down. The mixture therefore removes far too little heat from the hot gases, see above that the greater part of the amount of heat is dissipated by the gases, which increases the thermal efficiency of the furnace is greatly reduced.

The invention relates to a furnace for preheating a vitrifiable mixture, which is in the form of a mist distributed freely and without a fixed support essentially over the entire height of a preheating shaft falls in countercurrent to the hot flue gases, which emerge from the melting tank, which is in a lower than the preheating shaft.

The the OF INVENTION du ng object underlying b esteht therein in an oven, the vitrifiable mixture is introduced in the above manner and distributed in the preheating, the J Vorwärmschac ht before he d Strahlun g to protect the molten glass contained in the Üchmelzwanne . ~~~ 45

This object is achieved according to the invention in that between chmelzwanne de r S which contains the molten glass, and the larger part is ngeordnet Before wärmschachtes a n in substantial horizontal Sc ld ausHEeuerfestem material of a. '~~ ~~

According to a further feature of the invention, furnace for preheating a vitrified
Mixture

Applicant:

S. A. Glaverbel, Brussels

Representative:

Dr.-Ing. A. v. Kreisler, Dr.-Ing. K. Schönwald,
Dr.-Ing. Th. Meyer and Dr. JF Fues,
Patent attorneys, Cologne 1, Deichmannhaus

Named as inventor:

Edgard Brichard, Jumet;

Emile Plumat, Gilly;

Pierre Eloy, Lodelinsart;

Alfred Jacobs, Montigny-sur-Sambre;

Maurice Boffe, Fleurus (Belgium)

Claimed priority:

Belgium 7 February 1961 (477 301)

the screen preferably consists of several separate parts which partially overlap.

In a modified embodiment of the invention, the melting tank is in the lateral direction arranged offset relative to the preheating shaft.

Due to the design of the furnace, the heat radiated from the molten glass into the preheating shaft is captured and reflected into the melting tank. This reduces the temperature of the walls of the preheating shaft, and consequently the heat losses through these walls are also reduced. On the other hand, it is ensured that the pre-heating of the mixture takes place exclusively through the heat contained in the flue gases, and in this way the best possible recovery of this heat is achieved. Ultimately, the amount of heat extracted from the molten glass is reduced and, accordingly, the amount of heat that must be added to it in order to maintain the temperature required for processing.

709 517/97

The type of preheating of the mixture according to the invention also results in the following advantages:

1. The heat exchange surface is very large and corresponds to the total surface of the grains of the Mixture.

2. The residence time of the grains in contact with the flowing gases is after Can be adjusted as required (aerodynamic effect).

3. All the grains are only in contact with the gases , and no thermal conduction is required.

4. A segregation is because of the continuous mode of action and the. Dispersion of the grains not to be feared, even if the heavy grains reach the molten glass bath more quickly.

5. The operation and maintenance of the furnace are easy and inexpensive.

6. The higher preheating temperature, i. H. until the mixture melts, is only through that The temperature of the flue gases is limited.

In the drawing, two exemplary embodiments of the subject matter of the invention are shown.

F i g. 1 shows schematically in longitudinal section a furnace according to the invention,

F i g. 2 shows a modified embodiment of the furnace, also in longitudinal section.

The furnace according to FIG. 1 consists of a jacket 1 made of refractory material, which forms the melting tank 2 in the lower part and the preheating shaft 3 above it. At the upper end of the shaft 3 is the filling opening 4 of the furnace, which is closed by a flap 5. Slightly below the opening 4 there is an opening through which the smoke gases emerging from the melting tank can be discharged into the chimney. The vitrifiable mixture is introduced through the opening 4 and falls through the shaft 3 into the melting tank 2, which contains the molten glass 8, which is discharged through the channel 9. The melting tank with burners 10. provided by ,,, 'which hei'ße GaseH n g the esc hmolz ene glass iLein, -jjebTasen werden.TDie'Gase steigerfdänn in the shaft 3 · upwardly, they heat the falling grains of the mixture and finally through the opening 6 in the chimney.

According to the invention, between the melting tank 2 and the larger part of the preheating shaft 3 a substantially horizontal screen 11 made of refractory material is arranged on a part of the cross section of the shaft is limited, so that a passage 12 for the passage of the smoke gases and the mixture is left. Preferably, at a small distance above the screen 11 a similar screen 13 is arranged, but which is directed opposite, so that the screen 13 the Passage 12 covered and the passage 14 next to the screen 13 in the vertical direction above of the screen 11 is located. This arrangement of the screens is used for the smoke gases and the grains of the Mixture made a connection between the melting tank 2 and the shaft 3, which consists of the Passages 12 and 14 and from the channel 15 lying between the screens 11 and 13. the Radiation coming from the molten glass bath 8 is completely passed through the two screens 11 and 13 caught and reflected downwards. The screens are bevelled on the top 16 of the mix covered. The mixture falls from this accumulation on the upper screen 13 in a thin layer 21 down onto the accumulation on the lower screen 11 from which the Mixture falls into the molten glass bath 8 in a thin layer 22.

A modified embodiment of the oven is

ίο in F i g. 2 shown in which like parts with the same reference numerals are designated. According to FIG. 2 are the melting tank 2 and the shaft 3 not arranged in the mutual extension, but the melting tank 2 is relative to the lower End of the shaft 3 offset in the lateral direction. The melting tank 2 is surrounded by a vault 17 covered, which forms the reflective screen, while the shaft 3 at the lower end by a Bottom wall 18 is completed, the vault 17 and the bottom wall 18 being a part of the furnace shell 1 form. The upper end of the melting tank 2 is connected to the lower end of the shaft 3 connected by a passage 19, the grains of the mixture and the flue gases as a passage serves. In this arrangement, too, the radiation from the molten glass bath 8 is captured by the vault 17 and reflected down. This arrangement is enhanced when near the a screen 11 is arranged at the lower end of the preheating shaft 3. This screen catches part of the Indirect radiation directed from the melting tank 2 into the shaft 3 and prevents clogging of the passage 19 through the mixture, which also falls in a thin layer 22 and collects on the bottom wall 18, from which it enters the molten glass bath 8.

According to a very advantageous arrangement, the undersides of the screens 11, 13 or of the vault 17 are covered with a layer 20 made of a material with high reflectivity. As such, we d be ispielswe ise a Edelmet used all, w ith platinum. As a result, the amount of heat reflected from the molten glass bath 8 is increased, the heating of the screens or the vault is reduced, and the amount of heat that is lost through the vault 17 is also reduced.

Claims (4)

Patent claims: 1 .. furnace for preheating a vitrifiable arms' Mixture that is distributed in the form of a mist, free and without fixed support, essentially over the entire height of a preheating shaft, in countercurrent to the hot flue gases which fall from the melting tank, which is at a lower height than the preheating shaft , ~ d ä "du r'c hi in that between the melting furnace (2) containing the molten glass, and the greater part of the preheating shaft (3) is a substantially horizontal erechter shield made of refractory material angeordnefist." 2. Oferi'Tiacfi claim Ϊ, characterized in that the screen consists of several separate parts (11,13), "which partially overlap. 3. Furnace according to claim 1, characterized in that the melting tank (2) . containing the molten glass, in the lateral direction is offset relative to the preheating shaft (3) , in which the mixture is heated by the chewing gases. 4. Furnace according to claim 1, characterized in that the lower side of the screens (11, 13) and / or the vault (17) facing the molten glass is coated with a layer (20) made of a material with high Rellexionsvermogen. Documents considered: French Patent No. 1256 831. 1 sheet of drawings 709 $ 17/97 2.67 © Bundesdruckerei Berlin