JPH0229951B2 - RENZOKUSHIKISHOSEISOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a firing apparatus, and more particularly to an energy-saving continuous firing apparatus. As shown in Figures 1 to 3, conventional continuous firing apparatuses generally have a preheating zone 1, a firing zone 2, and a cooling zone 3 integrated. Therefore, the object to be fired 4 was continuously fired. To explain this with reference to the figure, the object to be fired 4 is loaded on a cart 5, pushed through the entrance 6 of the preheating zone 1 of the furnace, preheated in the preheating zone 1, and then fired in the firing zone 2. Next, it was cooled in the cooling zone 3, and thus fired in sequence. That is, the object to be fired 4 was preheated by introducing waste gas from the firing zone 2 and waste heat recovered from the cooling zone 3 into the preheating chamber 1 through a blower pipe (not shown). In the cooling zone 3, a blowing hole 7 is provided in the ceiling of the furnace, and cooling air is supplied from this hole 7 to cool the fired product 4. After cooling, a side wall hole provided in the side of the furnace is provided. 8 through a wind pipe (not shown) to the preheating zone 1. However, in the case of cooling the fired product 4, the pressure of the cooling air blown in from the blowing hole 7 is approximately the same as the gas pressure at the burner 9 of the firing zone 2 at the boundary between the firing zone 2 and the cooling zone 3. The pressure must be adjusted to be the same, and this pressure adjustment prevents the cooling air blown into the cooling zone 3 from flowing into the firing zone 2. In this way, the conventional continuous firing equipment has a preheating zone
Waste heat was used to preheat the product 4 to be fired in the cooling zone 3, and the product 4 to be fired could be sufficiently cooled in the cooling zone 3, so thermal efficiency could be increased to a certain degree compared to a single kiln that repeatedly operates intermittently. It was also possible to improve productivity and quality. However, the inventor, who has been engaged in the furnace construction business for many years, has conducted further research in order to further improve the continuous firing furnace, which was in a somewhat satisfactory condition as described above. As a result, in order to improve thermal efficiency, productivity, and quality in conventional continuous firing furnaces, it is essential to make the furnace length sufficiently long. This effort was made to develop a device that can be expected to have the same effects as a continuous firing furnace. In other words, an increase in the length of the furnace body not only results in a vast site area, a large amount of power, and an increase in the number of trolleys and other ancillary equipment, but also increases the heat loss due to heat dissipation from the furnace body, which results in This is because it was a cause of an increase in product costs. In addition, in conventional continuous firing furnaces, when the cooling air introduced from the outside into the cooling zone is adjusted in order to obtain optimal cooling conditions, this maintains the pressure balance at the boundary between the firing zone and the cooling zone. Waste gas from the sintering and firing zone flows into the cooling zone, and conversely, cooling air from the cooling zone flows back into the firing zone, causing a decline in the quality of the fired product. Furthermore, even if an attempt is made to use the heated air discharged from the cooling zone exhaust hole as the combustion air supplied to the burners in the firing zone in order to improve the combustion efficiency of the furnace, this discharged heated air will cause dust and waste in the furnace. Another problem was that it could not be used because it contained large amounts of gas and was contaminated. This invention improves the various problems with the conventional continuous firing equipment as described above, maintains the quality of fired products as good as before, further improves thermal efficiency and productivity, and also improves the length of the furnace body. The aim is to provide an energy-saving continuous firing device that is also shortened in size. The present invention will be explained below based on one embodiment of the present invention shown in FIGS. 4 to 6. FIG. 4 is a partial cross-sectional view showing the continuous firing apparatus of the present invention, and FIG. 5 is a longitudinal cross-sectional view of the furnace body of the same apparatus. In the figure, numeral 10 indicates the furnace body. This furnace body 10
In this case, a firing zone 12 is located in the center, a preheating zone 11 is located at one end, and a cooling zone 13 is located at the other end, and these are integrated. A heat-resistant door 14 is provided at the entrance 6 of the preheating zone 11 of the furnace body 10 , and a chimney 15 for discharging waste gas is provided at the side end. A cooling zone 13 is located on the opposite side of the preheating zone 11 across the firing zone 12.
is located. A heat storage cooling type heat exchanger 16 is attached to the cooling zone 13 at an intermediate portion thereof near the firing zone 12 . This heat exchanger 1
6 is installed on the inner wall and ceiling of the furnace, and its structure is a block-like structure in which the inner wall is made of a large number of heat-resistant steel pipes embedded in a refractory with high thermal conductivity (for example, magnesia). The outside of 16 is covered with a heat insulating material (for example, ceramic fiber) to prevent the heat accumulated from the object 4 to be fired inside from dissipating to the outside. A heat-resistant exit door 18 is provided at the exit 17 of the cooling zone 13. Also, 12 in the center
indicates the firing zone, where the firing chamber 19 is located,
A plurality of burners 9, 9 are attached to its inner wall. The combustion air supplied to this burner is supplied with heated air recovered by the heat exchanger 16 from the side wall and ceiling of the cooling zone 13 described above.
For this purpose, a pipe (not shown) of the heat exchanger 16 and a combustion air introduction pipe of the burner of the combustion chamber 19 are connected by a blower pipe 20. A rail 21 is laid on the floor of the furnace body 10 , and is orthogonally connected to guide rails 22 and 23 provided separately at both ends thereof.
Note that FIG. 6 shows a longitudinal cross-sectional view of the furnace body 10 . Reference numeral 24 indicates a box-type preheating chamber provided independently of the furnace body 10 , which is mounted on a guide rail 22 provided on the side of the preheating zone, and is capable of reciprocating in the direction of arrow 25. This preheating chamber 24 is
It has a closed box structure with a cavity inside that can store the trolley 5 carrying the object 4 to be fired while it is mounted on the guide rail 22, the inside is made of heat-resistant steel plate, and the outside is made of heat insulating material 26, such as rock wool. It is. A heat-resistant door 27 is provided in the preheating chamber 24 on the side opposite to the door 14 provided in the preheating zone 11 of the furnace body 10 to allow the object to be baked 4 to enter and exit the preheating chamber 24 . Reference numeral 28 is a box type cooling chamber for finally cooling the fired product 4, and like the preheating chamber 24 described above, it is mounted on the guide rail 23 and provided on the cooling zone side of the furnace body 10 . This cooling chamber 28 is also capable of reciprocating movement on the guide rail 23 in the direction of the arrow 29.
Like the preheating chamber 24, this structure is also a sealed structure with a cavity inside which can accommodate the trolley 5, but it has a cavity wall made of steel plate on the side wall, and holes for cooling air from the outside are provided here. I'll keep it. In this cooling chamber 28, there is a heat insulating door 41 for entering and exiting the fired product 4 from the furnace body 1.
0 on the side opposite to the cooling zone side. A side line 30 is provided in the middle by connecting the side ends of each of the guide rails 22 and 23 on which the preheating chamber 24 and cooling chamber 28 described above are mounted, and a drying chamber 31 is mounted on this side line 30. There is. This drying chamber 31 is for drying the objects to be fired 4 before preheating them, and is for drying the objects to be fired 4 placed on the trolley 5.
is mounted on the side track 30 and can be freely accessed and removed.The door 32 is opened and two carloads of the material to be fired 4, for example, are inserted therein and then dried. It is then taken out from the tank and then fed into the preheating chamber 24. In addition,
The drying chamber 31 is provided with a chimney (not shown) for discharging heated air, such as waste gas, used to dry the object 4 to be fired. A blower pipe is installed between the above-described furnace body 10 and the preheating chamber 24, cooling chamber 28, and drying chamber 31. That is, a blow pipe 34 is provided between the firing chamber 19 of the furnace body 10 and the preheating chamber 24 to send waste gas from the preheating zone 11 to the preheating chamber 24, and a blower pipe 34 is provided between the preheating chamber 24 and the drying chamber 31. A similar blower pipe 35 is arranged between them. Fans (not shown) for blowing air are provided at appropriate locations on these pipes. Additionally, there is a blower pipe 3 between the pipe of the heat exchanger 16 provided in the cooling zone 13 of the furnace body 10 and the cavity provided in the side wall of the cooling chamber 28.
6 is piped, and fans (not shown) are also provided at appropriate locations. Next, the operation of the continuous firing apparatus of the present invention having the above-described configuration will be explained. The material to be fired 4 is loaded onto the trolley 5 before the drying chamber 31, and this is transferred to the drying chamber 3.
Open the door 32 of 1 and store the trolley 5 inside.
After storage, the door 32 is closed, and moisture in the object 4 to be fired is removed here. The waste gas generated in the firing chamber 19 of the furnace main body 10 is sent to this drying chamber 31 via the preheating chamber 24 through blast pipes 34 and 35, so that the object to be fired 4 is sufficiently dried by the preheating. can do.
The dried object 4 is taken out from the drying chamber 31 by opening the door 33 of the drying chamber 31, and then runs along the side line 30 along with the cart 5 in the preheating chamber 24, which is specially installed at the end of the side line 30. will be moved towards. Next, the door 27 of the preheating chamber 24 is opened, and the above-mentioned dried material to be fired is fed into it together with the cart 5, where it is sufficiently preheated by the high temperature waste gas generated in the firing zone 12. Next, this preheating chamber 24 is connected to the preheating zone 11 of the furnace main body.
Move to the entrance 6 using the guide rail 22, adjust the position where the door 27 of the preheating chamber 24 and the door 14 of the furnace body 10 are facing each other, and open the door 27 and the door 14 almost simultaneously to release the object 4 to be fired. The loaded cart 5 is pushed into the preheating zone 11 of the furnace body 10 . After entering the furnace, the door 14 is closed and the object to be fired 4 is further sufficiently preheated in the preheating zone 11 of the furnace body 10 . Here, the high temperature waste gas flowing from the firing chamber 19 to the preheating zone 11 is sufficient to heat the heating, but it is of course possible to obtain a separate heat source here. The waste gas used for preheating in the preheating zone 11 is then blown to the preheating chamber, and excess waste gas is discharged from the chimney 15. The object to be fired 4, which has been sufficiently preheated again, passes through the preheating zone 11, moves to the firing zone 12, and is fired by a plurality of burners 9, 9 provided on the side wall of the firing chamber 19. During this firing, clean heated air blown from the heat exchanger 16 provided in the cooling zone 13 is used as the air supplied to the burners 9, 9, and the combustion effect can be significantly improved. The fired product 4 that has been fired is then transferred to the cooling zone 13
sent to. A heat exchanger 16 is installed in this cooling zone 13.
is provided, where the fired product 4 is primarily cooled. That is, cooling air is constantly fed into the heat exchanger 16 installed on the side wall and ceiling in the cooling zone 13, and after removing high heat from the fired product 4, it is discharged as combustion air. 4 is indirectly cooled here. The fired product 4 that has been primarily cooled in the cooling zone equipped with the heat exchanger 16 is sent to the further cooling zone 13, where it is secondarily cooled, and then finally sent to the cooling chamber 28. When this stage is reached, the door 41 of the cooling chamber 28 is closed to the furnace door 18.
Open both doors 18 and 41 at almost the same time, and move the fired product 4 along with the trolley 5 onto the guide rail 2.
3 to the upper cooling chamber 28, and quickly close the door 41 of the cooling chamber 28. After this, this cooling room 2
Cooling air is blown into the cavity wall of 8 from a blow pipe (not shown), and the baked product 4 is indirectly cooled in the same way as cooling in the heat exchanger 16 of the cooling zone 13. After the fired product 4 has been sufficiently cooled in the cooling chamber 28, the cooling chamber 28 is moved to the end of the guide rail 23, and the fired product 4, together with the trolley 5, is moved from the cooling chamber 28 to the side track 3.
Push out above 0. The empty cooling chamber 28 from which the trolley 5 loaded with the baked products 4 was pushed out onto the side track 30 is returned on the guide rail 23 and placed at the furnace outlet 17 of the cooling zone 13 . And the preheating chamber 2 of the furnace body 10
At the same time, the trolley 5 loaded with the objects 4 to be fired is inserted into the cooling zone 13, and at the same time, the objects 4 to be fired and the trolley 5 pushed out from the cooling zone 13 are loaded again, and cooling air is blown into the trolley 5. The above operations are performed continuously and firing is repeated. In addition, in the apparatus of the present invention, the heated air obtained from the regenerative cooling type heat exchanger installed in the cooling zone is clean and stabilized during furnace operation, so it can be used not only for combustion but also for drying and other purposes. It can also be used as a heat source. In addition, air may be directly blown to the heat storage cooling type heat exchanger without using air blown from the cooling chamber. In particular, if the drying room is not airtight, introducing waste gas may cause it to leak and worsen the surrounding work environment.In such cases, it is recommended to supply clean heated air from the cooling room mentioned above. Thus, these problems will be resolved. Furthermore, when carrying out the present invention, if drying takes a long time due to the shape of the fired product or other reasons, it is possible to dry for a long time without interfering with furnace operation by using a plurality of turntables, a spare side wire, etc. on the side wire. becomes possible. As explained above, the present invention provides an independently movable box-type preheating chamber on the preheating zone side of the furnace body, an independently movable box-type cooling chamber on the cooling zone side, and By installing a storage cooling type heat exchanger that enables indirect cooling of the fired product, clean heated air recovered from the cooling zone side is used as combustion air, which not only greatly improves thermal efficiency. This made it possible to significantly shorten the furnace length and further improve the quality of fired products. That is, in this invention, a preheating chamber is provided independently of the furnace main body, the pre-dried material to be fired is inserted into the preheating chamber, and the material to be fired is sufficiently preheated using waste gas supplied from the furnace main body. Since it is sent to the preheating zone of the furnace body, the preheating of the object to be fired can be uniformly and reliably performed by these preheating operations, and rapid preheating can be performed in the preheating chamber of the furnace body. Summer. In conventional continuous furnaces, the materials to be fired at room temperature are placed in the furnace, or
Or even if you use a drying oven in advance, the temperature will be at most 100℃.
However, by using the preheating chamber of the present invention, this can now be preheated to about 300°C. Furthermore, for cooling in the cooling zone, by installing a regenerative heat exchanger that indirectly cools the fired product, it is possible to rapidly cool the fired product without adversely affecting the fired product. There is no longer any problem of loss of pressure balance at the boundary between the cooling zone and the firing zone, which occurs in furnaces. Experiments have confirmed that by using such indirect cooling, good fired products can be obtained even when the firing temperature is rapidly cooled to 750°C. Conventionally, cooling air was blown in from the blowing holes in the cooling zone without using the indirect cooling method as in the present invention.
Since the fired product was directly cooled in this way, rapid cooling was not possible due to the adverse effects of rapid cooling on the fired product. Furthermore, in this invention, a closed type cooling chamber is provided on the above-mentioned cooling zone side independently of the furnace main body,
The fired product, which has been primarily cooled in the cooling zone of the furnace body, is inserted into this cooling chamber and cooled, so that the fired product can be pushed out of the furnace body while still maintaining a high temperature of 500 to 600℃. Summer. Furthermore, since the cooling in this cooling chamber is also indirect cooling, unlike direct cooling in conventional continuous firing furnaces, problems such as the occurrence of defective products caused by variations in cooling conditions have been solved. As a result, the yield of fired products increased by 3 to 5%. As described above, in the apparatus of the present invention, a preheating chamber is provided independently in the preheating zone of the furnace body, and a cooling chamber is provided independently on the cooling zone side, in which preheating of the object to be fired and cooling of the object to be fired are performed. As a result, the length of the furnace can be shortened by 20 to 30% compared to conventional equipment, and along with this, it has also become possible to save significantly on other ancillary equipment. Furthermore, in the apparatus of the present invention, clean air, normally heated to about 300°C, blown from a heat storage cooling type heat exchanger installed on the cooling zone side is used as the combustion air for the burners in the firing zone. As a result, combustion efficiency can be greatly improved compared to conventional continuous furnaces, and as a result, the number of burners can be reduced, resulting in approximately 20% fuel savings. In addition, this device connects a preheating chamber and a cooling chamber to the preheating zone inlet and cooling zone outlet when moving objects and carts into and out of the furnace body, so cold air from outside will not rush into the furnace during operation. can be prevented.
In conventional furnaces, when the exit door of the cooling zone was opened, a gust of wind entered the furnace, creating an abnormal flow of gas into the firing zone and preheating zone, which could lead to poor quality.
According to the present invention, stable operation can be performed without such problems.

[Brief explanation of drawings]

Figure 1 is a partial cross-sectional view of a conventional continuous firing apparatus, Figure 2 is a longitudinal cross-sectional view of the furnace body of the apparatus shown in Figure 1, Figure 3 is a cross-sectional view thereof, and Figure 4 is a main body of the furnace shown in Figure 1. FIG. 5 is a partial cross-sectional view of a continuous firing apparatus according to an embodiment of the invention, FIG. 5 is a vertical cross-sectional view of the furnace body of the apparatus shown in FIG. 4, and FIG. 6 is a cross-sectional view thereof. 4... Baked product, 5... Cart, 9... Burner,
10...furnace body, 11...preheating zone, 12...firing zone, 13...cooling zone, 24...preheating chamber, 28...
Cooling room, 31... Drying room, 16... Heat storage cooling type heat exchanger.

Claims (1)

[Claims] 1. A furnace body in which a preheating zone, a firing zone, and a cooling zone are provided in this order, and a box-shaped preheating chamber that is movably provided on a guide rail at the side end of the preheating body of the furnace body. , a drying chamber provided in front of this preheating chamber to dry the object to be fired before being transported to the preheating chamber; and a drying chamber that is movable so as to be movable toward and away from the guide rail at the side end of the cooling zone of the furnace main body. 1. A continuous firing device characterized by comprising a box-shaped cooling chamber provided in a box-shaped cooling chamber.