JP3082324B2 - Direct fire hot air circulation furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention heats an object to be processed by circulating a heating gas in a heating space, and heats the gas by burning a burner in a part of the gas flow path. And a direct-fired hot-air circulation furnace.

[0002]

2. Description of the Related Art As a direct-fired hot-air circulation furnace, for example, FIG.
(A) and (B). In other words, in these figures, a cylindrical heating chamber 6f having a heating space 7f for an object to be processed is formed in a hollow cylindrical furnace body 1f, and a space for gas flow is formed therebetween. It is provided in a double cylinder shape. In these, a plurality of zones 15f are defined in the cylinder core direction, and a space between the furnace body 1f and the heating chamber 6f is partitioned into small spaces 16f for the respective zones by partition walls 17f. In each zone 15f, the heating chamber 6f
An ejection port 18f for ejecting gas from the small space 16f into the heating space 7f, and an ejection port for extracting gas ejected from the ejection ports 18f and 19f and flowing through the heating space 7f to the small space 16f. 20f is provided. The small space 16f in each zone 15f is provided with a fan 21f for sending gas drawn from the outlet 20f to the jets 18f, 19f, and further heats the gas sent to the jets 18f, 19f. 24f is arranged such that the gas flow direction Af toward the jet ports 18f and 19f and the hot gas jet direction Bf from the burner 24f are in the same direction.

[0003]

In this conventional direct-fired hot-air circulating furnace, the object to be treated 10f is ejected from the ejection ports 18f and 19f and flows through the heating space 7f regardless of the zone in the heating space 7f. It has the feature that it can be quickly heated by a heating gas. However, when the gas for jetting from the jet ports 18f, 19f to the heating space 7f is heated by the burner 24f, the gas flow direction Af toward the jet ports 18f, 19f and the hot gas jet direction Bf from the burner 24f. Are oriented in the same direction, so their gases are very difficult to mix. Therefore one zone
If the length of 15f is long and the width of the former gas flow in the small space 16f is wide, both gases are ejected to the heating space 7f without being mixed, resulting in uneven temperature at each location. Therefore, the occurrence of such a problem is prevented by shortening one zone 15f. However, for this reason, the number of zones in a furnace of a certain length increases, and there are problems that a large number of fans and burners are required, equipment costs are high, and maintenance takes a lot of time. .

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art, and the flow direction of the gas toward the injection port and the injection direction of the high-temperature combustion gas from the burner are opposed to each other. By arranging the burners in such a direction that both gases are mixed well, one zone can be made longer, reducing the number of fans and burners, etc., and reducing the cost of equipment and maintenance. It is an object of the present invention to provide a direct-fired hot-air circulation furnace that can be reduced.

[0005]

In order to achieve the above object, a direct-fired hot-air circulating furnace according to the present invention has a cylindrical shape in which a hollow space is provided as a heating space for an object to be processed. The heating chamber is provided in a double cylinder shape in which a space for gas flow is formed between them, and in these, a plurality of zones are defined in the cylinder core direction, and a space between the furnace body and the heating chamber is provided. The space is partitioned by partition walls into small spaces for each zone, and in each zone, the heating chamber is provided with an ejection port for ejecting gas from the small space into the heating space, and a heating port for ejecting gas from the ejection port. An outlet for drawing gas flowing through the space into the small space is provided, and the small space in each zone is provided with a fan for sending gas drawn from the outlet to the outlet, And a burner to heat the gas sent to In direct-fired hot-air circulating oven you are,
The burner is arranged such that a gas flow direction toward the jet port and a high-temperature combustion gas jet direction from the burner are opposed to each other.

[0006]

The gas for heating the object to be processed is ejected from the ejection port into the heating space, and heats the object in the process of flowing through the space. The gas is drawn out from the outlet after flowing through the heating space. The extracted gas is mixed with the high-temperature combustion gas from the burner on the way to the injection port again to increase the temperature.
In this case, the flow directions of the two gases are opposite to each other, so that the mixing of the two gases is good. The gas whose temperature has been increased in this way is again ejected from the ejection port into the heating space.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 4, reference numeral 1 denotes a hollow cylindrical furnace body, 2 denotes a charging port in the furnace body, and 4 denotes an outlet, which are opened and closed by vertically movable doors 3 and 5, respectively. . Numeral 6 denotes a cylindrical heating chamber disposed in the furnace body 1, and as shown in FIG. 2, has a double cylindrical shape in which a space for gas flow is formed between the furnace body 1 and the furnace body. The inside is a heating space 7. The heating chamber 6 has one end 6a and the other end 6b serving as an inlet and an outlet, respectively, and these are connected to the charging port 2 and the delivery port 4, respectively. Reference numeral 8 denotes a rail for transporting the workpiece, which is supported by a number of columns 9 penetrating the bottom wall of the heating chamber 6. Reference numeral 10 denotes an object to be processed, for example, a plate-like ingot of aluminum, which is mounted on a shoe 11 movably mounted on the rail 8 and conveyed along the rail 8. Reference numeral 12 denotes a pusher device, which is an example of a device for transporting the workpiece 10, and can push the shoes 11 one by one from the loading port 2 toward the heating space 7. By such a pusher device 12, a large number of objects to be processed 10 are sent into the heating space 7 with the shoes 11 connected in a daisy chain as shown in FIG. 13 is a device for returning the shoe 11, and the workpiece 10 is connected to the outlet 4
After sending out from the
To return to the charging inlet 2 side from the side of the Next, FIG.
Reference numeral 15 denotes a plurality of zones defined in the furnace core 1 and the heating chamber 6 in the cylinder core direction. Hereinafter, each of these zones 15 will be described. Reference numeral 16 denotes a small space, in which the furnace body 1 and the heating chamber 6 are arranged.
Is formed by partitioning the space between them by a partition wall 17 for each zone. Numerals 18 and 19 denote spouts provided on the bottom wall of the heating chamber 6, and are provided at a plurality of locations in the length direction of the zone 15 (the left-right direction in FIG. 1). ). Reference numeral 20 denotes an outlet provided at the top of the heating chamber 6, respectively. Reference numeral 21 denotes a circulation fan whose suction port is disposed so as to face the outlet 20, and is rotated by a motor (not shown) provided outside the furnace. Reference numeral 23 shown in FIG. 4 is a well-known guide plate for guiding gas blown from the fan 21. Numeral 24 denotes a burner. The flow direction A of the gas blown from the fan 21 toward the jet port 18 and the burner 24
The fan 21 is mounted on the furnace body 1 in such a manner that the side of the fan 21 is directed so that the direction B in which the high-temperature combustion gas is blown out of the fan 21 is opposed.

In the furnace having the above-mentioned structure, a large number of objects to be treated 10 are fed into the heating space 7 in a cascade in the state shown in FIG. Then, the charging entrance 2 is closed by the door 3. In this state, the fan 21 and the burner 24 are operated in each zone 15 in the furnace. Fan 21
The gas in the direction of arrow A sent from the burner 24 and the high-temperature combustion gas in the direction of arrow B from the burner 24 are mixed well, and the hot gas reaches the injection ports 18 and 19. Then, they are jetted into the heating space 7. The high-temperature heating gas ejected into the heating space 7 hits the workpiece 10 and flows upward along the workpiece, thereby heating the workpiece 10 in the process. The gas reaching the upper part of the heating space 7 is drawn out from the outlet 20 by the fan 21, further sent in the direction of the arrow A, and again sent to the burner 24.
The temperature is increased by the high-temperature gas from the furnace. The gas circulation as described above is continuously performed, and the processing target 10 is heated to a predetermined high temperature. When all the workpieces 10 are heated to a predetermined temperature, the door 5 is opened and the workpieces 10 are sequentially sent out from the outlet 4 to a next step, for example, a rolling step. When all the objects to be processed 10 have been sent out in this manner, a new object to be processed is charged into the heating space 7 again, and the heating is performed. The loading and delivery of the workpiece 10 is not limited to the above-described method, and every time one or a plurality of workpieces 10 which have already been heated at the delivery port 4 are sent out from the delivery port 4 through the delivery port 2, Heating space 7
It may be performed by repeatedly charging the inside.

[0009]

As described above, according to the present invention, when a large number of workpieces 10 are put into the heating space 7 and heated, the jet ports 18 and 15 are provided in any of the zones 15 and 15 in the cylinder core direction. 19
Can be heated by the gas which is ejected into the heating space 7 and flows through the heating space 7, so that the object 10 to be treated, which is put in any place in the heating space 7, can be quickly heated.

In each of the zones 15, the jet ports 18,
When the temperature of the gas for jetting from 19 into the heating space 7 is increased by the burner 24, the flow direction A of the gas toward the jet ports 18, 19 and the jet direction B of the high-temperature gas from the burner 24 are opposed to each other. Therefore, the former gas and the latter high-temperature gas are in a state of being largely agitated with each other, and therefore, the length of one zone 15 is long, the width W of the small space 16 is wide, and the flow of the former gas flows. Even if the width is wide, both gases have the feature of being well mixed. This means that even if the length of one zone is set to be long, the gas can be jetted from the jet port without temperature unevenness.Therefore, the effect of reducing the number of zones in a furnace of a fixed length can be obtained. Yes, as a result, the number of fans 21 and burners 24 is small enough, and there is utility that equipment costs can be reduced and maintenance can be facilitated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a shoe pusher furnace.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a diagram showing a part of FIG. 2 in detail.

FIG. 4 is a horizontal cross-sectional view showing a cross-sectional structure of one zone taken along a line IV-IV in FIG. 3;

FIG. 5A is a longitudinal sectional view of a conventional direct-fired hot-air circulation furnace,
(B) is a sectional view taken along line BB in (A).

[Explanation of symbols]

 1 Furnace body 6 Heating chamber 7 Heating space 10 Workpiece 18, 19 Spout 20 Outlet 21 Fan 24 Burner

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F27D 7/02 C21D 1/767 F23C 11/00 320 F27B 9/02

Claims (1)

(57) [Claims] 1. A hollow cylindrical heating chamber having a heating space for heating an object to be processed in a hollow cylindrical furnace body, and a double cylindrical space in which a space for gas flow is formed between the two heating chambers. In these, while defining a plurality of zones in the cylinder core direction, the space between the furnace body and the heating chamber is divided into small spaces for each zone by a partition wall, in each zone, the heating chamber A jet port for jetting gas from the small space into the heating space, and a jet port for drawing gas jetted from the jet port and flowing through the heating space to the small space. In the above small space, a direct-fired hot-air circulating furnace in which a fan for sending gas drawn out from the outlet to the jet outlet and a burner for heating the gas sent to the jet outlet is arranged. In the above, the burner controls the flow of gas toward the jet port. A direct-fired hot-air circulating furnace, wherein the hot-air circulating furnace is disposed so that the direction of the high-temperature combustion gas ejected from the burner is opposite to the direction of the high-temperature combustion gas.