JPS6121170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode support structure for direct current heating in a glass melting furnace.

Conventionally, since glass is a good electrical conductor at high temperatures, glass raw materials have been made by inserting an electrode into the molten glass and using the Joule heat generated when electricity is applied directly to the molten glass through the electrode. The methods used include melting and clarification using this Joule heat, and methods using heavy oil or gas combustion as an auxiliary heat source for melting.

Regarding the insertion structure of electrodes for supplying electric power into molten glass, there are two main types: one is to insert them vertically into the furnace from the hearth, and the other is to insert them horizontally into the furnace from the furnace wall. Each type has its own unique characteristics, such as its ability to provide convection to glass, and all are commonly used.

By the way, in the latter type where the electrode is inserted horizontally into the furnace by penetrating the furnace wall, an electrode insertion brick having a through hole penetrating into the furnace from outside the furnace is provided in a part of the furnace wall, and the carbon When using an electrode, insert the electrode directly into the through hole. When using a molybdenum electrode, it is easily oxidized when exposed to the atmosphere at high temperatures, so the electrode 1 is inserted into the water cooling device 2 as shown in Figure 1. It is common to insert the electrode device 3 into a through hole as an internally constructed electrode device 3.

However, the above horizontal electrode insertion method has the following problems. This is because the portion of the surface of the electrode insertion brick 5 on the molten glass 9 side (inner side of the furnace) around the through hole 6, especially the upper part of the through hole 6, is eroded by the hot molten glass. This erosion is caused by the convection of the molten glass 9 that occurs around the electrode 1 due to direct current heating by the horizontal electrode 1, especially the upward flow of high-temperature molten glass, and this flow strongly melts the upper part of the through hole 6 of the electrode insertion brick 5. The erosion part 7 becomes deeper and deeper as the furnace operates.
The cracks will spread widely and the thermal shock will cause cracks (which are especially noticeable in cases with water cooling equipment), eventually leading to the risk of collapse. This period was shorter than the durability period of the other so-called tank blocks that made up the furnace wall, and was a major factor in determining the lifespan of the furnace.

The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an electrode support structure that can effectively prevent erosion of electrode-inserted bricks.

That is, the gist of the present invention is to prevent the upward flow of high-temperature molten glass that occurs around the electrode inserted horizontally into the furnace from directly contacting the surface of the electrode-inserted brick, and for this purpose, An electrically insulating refractory sleeve is passed loosely through the through hole of the electrode insertion brick, and the electrode (or electrode device) is supported by penetrating the sleeve with one end protruding a certain length into the molten glass. The upward flow of the surrounding high-temperature molten glass is directed away from the surface of the electrode-inserted brick by a sleeve surrounding the electrode and protruding into the furnace, thereby preventing erosion of the electrode brick.

Hereinafter, the present invention will be explained in detail according to embodiments shown in the drawings.

Embodiment In FIG. 3, a part of the side wall 8 of the glass melting furnace 10 is provided with an electrode insertion brick having a through hole 6 for horizontally inserting the rod-shaped electrode 1 made of molybdenum into the molten glass 9 in the furnace. 5 is provided in the through hole 6, and a cylindrical electrically insulating refractory sleeve 21 consisting of a plurality of divided pieces 20, 20' divided into two in the axial direction shown in FIG. The electrode 1 is inserted into the furnace so as to protrude a certain length, and the part of the electrode 1 which is exposed to the atmosphere and which becomes high temperature due to heat conduction is inserted into the cylindrical water cooling device 2, and the part of the electrode 1 is inserted into the through hole. It passes through the sleeve 21 in 6 and is inserted into the furnace.

Next, a method of using the device of the present invention will be explained.

The molten glass 9 is heated by passing current between the electrode 1 and an electrode (not shown) electrically opposing the electrode 1, and an upward flow of high-temperature molten glass occurs around the insertion portion of the electrode 1 into the furnace. However, this upward flow does not come into direct contact with the surface of the electrode insertion brick 5 as in the case of the conventional device, but rises at a position away from the electrode insertion brick 5 due to the sleeve 21 projecting a certain length into the furnace.

However, even in such a configuration, the protruding portion of the sleeve 21 in the furnace is gradually eroded and shortened by the high temperature molten glass due to changes over time, and the effect of keeping the upward flow of the high temperature molten glass away from the electrode insertion brick 5 is reduced. At this point, the effect of keeping the upward flow away is restored by pushing the part of the sleeve 21 outside the furnace into the long furnace to compensate for the shortened part due to erosion.

At this time, one set 20, 2 of the divided pieces of the sleeve 21
It is also possible to push one unit length of 0' and drop one set of eroded tip sections into the furnace, and then position a new set at the tips. In any case, if the pushed length is equal to the length of one unit of the divided pieces of the sleeve 21, it goes without saying that one additional set can be inserted.

In the case of a glass melting furnace in which the amount of molten glass pulled up is approximately constant, the pushing operation described above only needs to be carried out for a fixed period of time because the erosion of the in-furnace protrusion of the sleeve 21 progresses at a constant speed. It is something.

As described above, according to the apparatus of the present invention, the sleeve 21 is periodically pushed out into the furnace and the sleeve 21 is
By compensating for the erosion amount in step 1, it is possible to prevent the electrode brick 5 from being eroded by the upward flow of high-temperature molten glass, and furthermore, the cooling by the water cooling device directly affects the electrode insertion brick and causes cracks in the electrode insertion brick. This problem has the advantage of being solved by the heat insulating effect of the sleeve. Therefore, this device has the remarkable effect of eliminating the problem of shortening the life of the furnace due to the danger of the electrode-inserted bricks collapsing due to erosion and cracking, which is the case with conventional devices.

In the above embodiment, the sleeve 21 is divided into divided pieces 20, 20' in the axial direction and in a plane perpendicular to the axial direction.
Although the sleeve is constructed by integrating multiple sleeves, in some cases it may be constructed as an integrated sleeve, or it may be simply divided into two parts in the axial direction and the pushing lengths of the upper and lower parts can be freely adjusted. Moreover, it is also possible to provide a concave and convex shape that fits each other on the dividing surface (continuous joint surface in the axial direction) perpendicular to the axial direction, so that rotation is applied when the sleeve is pushed in, thereby making insertion easier.

[Brief explanation of the drawing]

FIG. 1 shows the cross-sectional shape of the electrode insertion brick part of the conventional structure. FIG. 2 shows a front view of the electrode insertion brick section as seen from inside the furnace. FIG. 3 shows a cross-sectional shape of an electrode insertion brick part according to an embodiment of the present invention. FIG. 4 shows a front view of the electrode insertion brick part according to the same embodiment as seen from inside the furnace. FIG. 5 is an explanatory diagram of one unit of the sleeve according to the same embodiment. DESCRIPTION OF SYMBOLS 1... Electrode, 2... Water cooling device, 3... Electrode device, 4... Power connection part, 5... Electrode insertion brick,
6... Through hole, 7... Erosion part, 8... Furnace wall, 9...
Molten glass, 10... Melting furnace, 11... Hearth, 1
2... Crack, 20, 20'... Sleeve division piece,
21...Sleeve.

Claims (1)

[Scope of Claims] 1. In a glass melting furnace of the type in which a horizontal electrode or an electrode device for directly heating molten glass by passing through a side wall of the melting furnace and inserted into the molten glass in the furnace, An electrode insertion brick having a through hole for electrode insertion is arranged in a part of the side wall of the furnace, and an electrically insulating refractory sleeve with one end protruding a certain length into the molten glass in the furnace is inserted into this through hole. An electrode support structure characterized in that the electrode or electrode device is further fitted into the sleeve and supported so that a portion substantially forming the electrode is inserted into the molten glass. 2. The electrode support structure according to claim 1, wherein the sleeve made of electrically insulating refractory is constituted by divided pieces in the axial direction. 3. The electrode support structure according to claim 1 or 2, wherein the sleeve made of electrically insulating refractory material is constituted by divided pieces divided at right angles in the axial direction. 4. The electrode according to claim 2 or 3, characterized in that the sleeve made of electrically insulating refractory material has a concavo-convex shape that can be fitted to each other on divided surfaces that are divided at right angles in the axial direction. Support structure.