JPH066752B2 - Circulating gas supply device in floating furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a plenum chamber in a floating furnace provided so as to move a metal strip material (strip) in a state of being levitated by a circulating gas ejected from the plenum chamber. To a circulating gas supply device for

[Conventional technology]

A plenum chamber type floating furnace is often used as a device for performing heat treatment such as annealing on a metal strip material (strip). This furnace blows hot air jets from both the upper and lower sides of the strip-shaped material so that the strip-shaped material is floated by the plenum chamber (float). The feature is that a product can be obtained.

The high temperature gas (eg, 1150 ° C.) supplied to the plenum chamber is circulated and blown through the blower, but if the heat resistance of the blower (metal fan) is taken into consideration, the high temperature gas will be blown. Allowable temperature is 85
The limit is about 0 ° C. Therefore, Japanese Patent Publication No. 49-1690
In order to prevent heat damage to the blower, a cooler is attached to the suction side of the blower.The high temperature gas is once cooled to about 800 ° C by the cooler before sucking the blower, and the heater after discharging the blower is used. The method of heating to a high temperature again is used.

FIG. 7 is a drawing showing a specific example thereof, in which a pipe b extending from the side wall of the furnace body a to the outside of the furnace is connected to a blower e with a cooler c provided therebetween. The pipe f extending from the blower e is provided so as to face the plenum chamber h in the furnace with the heater g interposed therebetween.

[Problems to be solved by the invention]

Therefore, in the above method and apparatus, the high temperature gas (for example, 1150 ° C.) supplied to the plenum chamber
For the required capacity of, all of it is cooled to a blower heat resistant temperature (eg 800 ° C) and heated again to a high temperature,
Very large energy loss (eg 594,000 kc
There is a problem in that it causes al / h. The above problem can be solved by changing the material of the blower from ceramic to metal, but there is a problem in that the cost becomes high.

The present invention has made an attempt to solve the above-mentioned conventional problems and aims to reduce the loss of thermal energy by making the gas amount and temperature supplied to the plenum chamber equal to those of the conventional method. However, there is a problem to be solved by the present invention. That is, according to the present invention, only a part of the required volume of the hot gas supplied to the plenum chamber is supplied to the plenum chamber by the blower, and the rest is supplied to the plenum chamber through the ejector suction action. Of the required capacity, it is only necessary to send it to the blower for cooling and reheating, and the remaining required quantity can be sent to the plenum chamber at high temperature. Means and actions are as follows.

[Means for solving the problem] Of the required amount of circulating gas, a part of the circulating gas is ejected from the blower through the cooler and supplied to the plenum chamber, and the remaining necessary amount is the ejected flow of the blower. To the plenum chamber via.

A heater is provided between the cooler and the blower or at any position except for the part communicating only with the cooler, and the jet flow of the jet nozzle formed on the blower side is interposed between the blower and the plenum chamber. An ejector is provided outside the furnace so that the high temperature gas can be sucked through, and the tip of a bypass pipe branching between the furnace body and the cooler is connected to the ejector.

[Work]

Of the required amount of circulating gas, a part of the circulating gas is supplied to the plenum chamber in a reheated state via the cooler, the blower and the ejector. Further, the remaining circulating gas is supplied to the plenum chamber from the bypass pipe through the ejecting action of the ejector while maintaining the high temperature state.

〔Example〕

Specific examples of the present invention will be described below with reference to the accompanying drawings.

In both sides of FIGS. 1 and 2, 1 is a floating furnace, 2 is a heating device, and 3 is a cooling device provided adjacent to the heating device 2. The heating chamber 2'formed in the heating device 2 and the cooling chamber 3'formed in the cooling device 3 accommodate plenum chambers 4 ... Same plenum chamber 4
Are provided so that the strip-shaped material (strip) 6 can be floated through the high-temperature gas ejected from the plurality of ejection holes 5 embedded in the facing surfaces. Further, although not shown, a burner is attached to the heating chamber 2 ', and a cooling chamber 3'is provided.
A cooler 7 is attached to this. Reference numeral 8 indicates an introduction roll, and 9 indicates a discharge roll. 16 is a furnace body of the heating device 2,
The pipe 1 is made to communicate with the heating chamber 2'from the side wall of the furnace body 16.
0a is extended. The pipe 10a is provided with a cooler 11 interposed. Its tip is connected to the blower 12. A pipe 10b extends from the blower 12, and a heater 13 is provided on the pipe 10b. Further, the tip of the pipe 10b is provided with a taper portion which is tapered, and a jet nozzle portion 12 'is provided, while a funnel portion 14 is provided to face the jet nozzle portion 12'.
The funnel portion 14 and the jet nozzle portion 12 ′ form an ejector 15. Then, the pipe 10c is extended from the funnel portion 14 of the ejector 15 toward the inside of the furnace body 16,
Its tip is provided so as to face the plenum chamber 4 located below the heating chamber 2 '. And again, the pipe 10
A bypass pipe 10 'is extended from the middle of the pipe a, and its tip is provided so as to face the ejector 15 portion. Although not shown, the plenum chamber 4 located above the heating chamber 2'is also provided with the same supply device as above.

Further, FIGS. 3 to 6 are the same as those in the embodiment shown in FIG.
The heater 13 is installed at a different place, and
As shown in the figure, the heater 13 can be attached to the pipe 10c at a position close to the outer wall of the furnace body 16,
It is also possible to install it in the middle of the bypass pipe 10 'as shown in FIG. And again, as shown in FIG.
It is also possible to install the heater 13 by interposing it between the outer wall of the furnace body 16 and the branch point of the bypass pipe 10 ', and the suction of the pipe 10a on the inner wall of the furnace body 16 as shown in FIG. It is also possible to provide a partition plate 18 so as to surround the opening 17 and to mount the heater 13 between the partition plate 18 and the ceiling surface inside the furnace body 16.

Next, the operation will be described. In the embodiment shown in FIG. 2, the atmospheric gas heated to a high temperature in the heating chamber 2'is sucked in through the suction port 17 and only a part thereof flows to the blower 12 side, and the remaining most part is branched on the way. After that, it flows into the bypass pipe 10 '. More specifically, a part of the high-temperature gas flowing to the blower 12 side is cooled to the heat resistant temperature of the blower 12 by the cooler 11, and then the blower 1
Sent to 2. Then, the gas discharged from the blower 12 is heated to the original set temperature of the high temperature gas by the heater 13, and then ejected as a high-speed, high-pressure jet stream from the jet nozzle 12 '. At this time, the ejector 15 has a function of sucking the high-temperature gas around the jet flow. That is, most of the high temperature gas that has flowed into the bypass pipe 10 ′ side via the ejector 15 can be sucked, and the required volume of gas can be supplied to the plenum chamber 4 together with the gas on the blower 12 side. The same effect as above can be obtained in the upper plenum chambers 4 ... Then, by ejecting the high-temperature gas from the ejection holes 5 of the upper and lower plenum chambers 4, the strip material 6 is levitated and simultaneously heat-treated. Further, the high temperature atmospheric gas filled in the heating chamber 2'can be circulated and used again by sucking it from the suction port 17. Also in the embodiment shown in FIGS. 3 to 6, the same operation as above can be obtained.

〔The invention's effect〕

The present invention is configured as described above, and in the plenum chamber type floating furnace as described above, only a part of the required volume of the high temperature gas supplied to the plenum chamber is supplied to the plenum chamber by the blower. However, since the rest is supplied to the plenum chamber from the bar-pass pipe through the suction action of the ejector, it is sufficient to cool and reheat only the amount sent to the blower out of the required capacity, and the remaining required amount is high temperature. It has become possible to supply it to the plenum chamber as it is.

That is, it has become possible to minimize the loss of heat energy, which in turn leads to a reduction in manufacturing cost.

[Brief description of drawings]

FIG. 1 is an overall sectional view of a floating furnace. FIG. 2 is a drawing showing an embodiment of the present invention, which is a side sectional view of a main part of a heating device in the furnace. 3 to 6
FIG. 7 is a side sectional view of a main part showing another embodiment of the present invention, and FIG. 7 is a side sectional view of a heating device showing a conventional structure. DESCRIPTION OF SYMBOLS 1 ... Floating furnace, 2 ... Heating device, 2 '... Heating chamber, 3 ... Cooling device, 3' ... Cooling chamber, 4 ... Plenum chamber, 5 ... Jet hole, 6 ... Strip material, 7 ... Cooler, 8 ... Introducing roll, 9 ... Ejecting roll, 10a, 10b, 10c ... Pipe, 10 '... Bypass pipe, 11 ... Cooler, 12 ...
Blower, 12 '... Jet nozzle, 13 ... Heater, 14
... Funnel part, 15 ... Ejector, 16 ... Furnace body, 17 ... Suction port, 18 ... Partition plate.

Claims (6)

[Claims] 1. A blower for circulating high-temperature gas is provided outside the furnace body, while the suction side of the blower communicates with the furnace body through a cooler, while the discharge side of the blower faces a plenum chamber in the furnace body. In the floating furnace, the ejector is provided outside the furnace so that the high temperature gas can be sucked through the jet flow of the jet nozzle formed on the blower side by interposing it between the blower and the plenum chamber. Circulating gas supply in a floating furnace that connects the tip of a bypass pipe branching from the space between the ejector and a heater between the cooler and the blower or at any position except the part that communicates only with the cooler. apparatus. 2. A circulating gas supply device in a floating furnace according to claim 1, further comprising a heater provided between the blower and the ejector. 3. The circulating gas supply device in a floating furnace according to claim 1, further comprising a heater provided between the ejector and the plenum chamber. 4. The circulating gas supply device in a floating furnace according to claim 1, wherein a heater is provided in the bypass pipe. 5. The circulating gas supply device in a floating furnace according to claim 1, further comprising a heater interposed between the branch points of the furnace body and the bypass pipe. 6. The circulating gas supply device in a floating furnace according to claim 1, wherein a heater is provided in the vicinity of the suction port in the furnace body.