JPH0222630Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an electric furnace used for calcining ceramic raw materials that generate corrosive gas when heated for the purpose of denitrification and deoxidation. .

(Prior art) Conventionally, an electric furnace with a quartz tube with excellent corrosion resistance placed horizontally inside the furnace body has been used to pre-sinter ceramic raw materials such as zirconia, which generate corrosive gas when heated. Ceramic raw materials in a container called a pod are stored inside this quartz tube and heated electrically.
The corrosive gas generated is discharged outside the furnace through a chimney that communicates with the end face of the quartz tube. However, because a large weight acts on the lower surface of the quartz tube, cracks are likely to occur in the quartz tube, and since a rectangular sheath is inserted into a cylindrical quartz tube, wasted space is created inside the quartz tube, resulting in a small storage capacity. In addition, the end of the quartz tube needs to protrude from the furnace body in order to prevent corrosion of the furnace body, so the temperature distribution inside the quartz tube becomes uneven, and it is difficult to put the pod in and out of the quartz tube. In addition to many problems such as being difficult to perform and poor workability, there was also a sanitary problem in that workers were likely to inhale corrosive gas inside the quartz tube when removing the pods.

(Purpose of the invention) This invention was completed with the aim of solving these conventional problems and creating an electric furnace that has a long life, has a large capacity, has good workability, and does not cause hygiene problems. It is something.

(Structure of the invention) The invention consists of a quartz tube with a corrosion-resistant lid at the upper end for storing the materials to be fired, which is placed inside the furnace body so that the lower end of the quartz tube faces the furnace bottom, which is closed off by an elevating trolley. It is characterized by being vertically installed, and will be described in detail below with reference to illustrated embodiments.

In the figure, 1 is a furnace body electrically heated by a heater 2 such as a SiC heating element, and 3 is a quartz tube erected vertically inside the furnace body 1 for storing the object to be fired. The lower end of the quartz tube 3 is a through hole 5 made in the hearth bottom 4.
In addition, the top end of the quartz tube 3 is equipped with a lid 7 with a chimney 6 made of a corrosion-resistant, non-breathable material such as alumina refractory. The inside is isolated from the inside of the furnace body 1. An elevating type truck 8 is provided in the lower part of the furnace body 1, and the elevating type truck 8 can be lifted by a cylinder or other suitable elevating mechanism 9 to a height where its upper surface closes the furnace bottom 4. On the top surface of the elevating cart 8, there is a sheath stand 10 at a position corresponding to each quartz tube 3.
A cylindrical sheath 11 of a size that can be housed inside the quartz tube 3 is filled with a material to be fired, and then stacked in multiple stages on a sheath table 10. In addition, 12 is a sheath lid that is placed on the uppermost sheath 11, 13 is a furnace material for closing the bottom of the hearth disposed on the upper surface of the elevating truck 8, and 14 is a rail for pulling out the truck.

In this structure, the elevating cart 8 is pulled out onto the rail 14, the pods 11 filled with the materials to be fired are stacked in multiple stages on the upper surface of the sheath stand 10 of the elevating cart 8, and then placed directly under the furnace body 1. If it is raised by the lifting mechanism 9 together with the lifting trolley 8, the sheath 11
is housed inside a quartz tube 3 for storing the objects to be fired, which is vertically installed inside the furnace body 1 and has a corrosion-resistant lid 7 at the upper end, and is also used for closing the bottom of the furnace with an elevating cart 8. The furnace material 13 seals the furnace bottom 4 and the lower end of the quartz tube 3. In this way, the object to be fired is temporarily fired while being sealed inside the quartz tube 3 of the electrically heated furnace body 1, and the corrosive gas generated at this time is removed from the furnace by the quartz tube 3, which has excellent corrosion resistance. The gas is guided from the chimney 6 to the gas treatment device and treated while being prevented from coming into contact with the body 1. During this firing, no load is applied to the quartz tube 3, so there is no risk of cracking, and since the quartz tube 3 is entirely housed within the furnace body 1, there is no possibility of uneven temperature distribution. Without any
Therefore, the effective soaking area can be widened. After the preliminary firing is completed in this way, by lowering the elevating cart 8, the pod 11 can be easily taken out below the furnace body 1.
There is no risk of workers inhaling corrosive gas at this time. Further, at this time, outside air suddenly flows into the interior of the furnace body 1, but the quartz tube 3 has excellent thermal shock resistance, so it does not break.

(Effects of the invention) As is clear from the above explanation, this invention has a quartz tube vertically installed inside the furnace body, so no load is applied to the quartz tube, so there is no risk of cracks occurring, and it is uniform. It has a wide temperature distribution area, is easy to insert and remove, and there is no risk of workers inhaling corrosive gas. Furthermore, by making the cross-sectional shape of the quartz tube and the cross-sectional shape of the sheath similar, the present invention eliminates wasted space within the quartz tube and can approximately double the storage capacity of the materials to be fired. Its practical value is extremely great as it eliminates the problems of conventional electric furnaces of this type.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, and FIG. 2 is a partially cutaway plan view. 1... Furnace body, 3... Quartz tube, 4... Hearth bottom, 7...
...Lid body, 8...Elevating trolley.

Claims (1)

[Scope of utility model registration request] A quartz tube 3 for storing objects to be fired, which is equipped with a corrosion-resistant lid 7 at the upper end, is vertically placed in the furnace body 1 with the lower end of the quartz tube 3 facing the furnace bottom 4 which is closed by an elevating trolley 8. An electric furnace characterized by being installed vertically.