JP3082327B2 - 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 relates to a hot air circulating furnace for circulating hot air into an accommodation room for an object to be heated and performing heat treatment of the object.

[0002]

2. Description of the Related Art For example, a hot-air circulation furnace (aging furnace) for performing aging annealing of a long aluminum mold material is shown in FIG.
As shown in FIG. 1, a processing object storage chamber 72 for storing a processing object W in a furnace body 71 and a hot air circulation path 73 extending in parallel to the processing object storage chamber 72 are provided. A circulating blower 74 is installed in the radiant tube 7.
A type that circulates the hot air heated by the method 5 is generally used.

[0003]

In the hot-air circulating furnace 70 having the above-mentioned structure, since the workpiece W is long, it is necessary to switch the hot-air circulating direction during the furnace operation in order to equalize the temperature. . Conventionally, the direction of rotation of the blower 74 is switched for this purpose, so that the efficiency of the blower 74 at the time of reverse rotation is reduced, and the air volume is also reduced. Motor 7
The frequent start and stop of No. 6 causes wear of each part and also has a problem that it takes time to switch. It is also conceivable to provide two blowers at both ends of the furnace body 71, but there is a problem that equipment costs and installation space are increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a hot air circulating furnace capable of quickly and easily switching a hot air circulation direction without changing a rotation direction of a blower. .

[0005]

According to the present invention, there is provided a hot-air circulating furnace having a hot-air circulating passage communicating with a processing chamber at both longitudinal ends of a furnace body. A two-way discharge type blower is installed in the middle part of the furnace, and one discharge port of the blower is connected to the open end of the hot air circulation path from one end of the furnace body to the blower, and from the other end of the furnace body. The other discharge port of the blower is connected to an open end of the hot air circulation path leading to the blower, and the suction port of the blower is connected to an intake path communicating with both open ends, and the discharge direction of the blower is switched. A discharge direction switching damper, and a suction direction switching damper provided in the intake path and switching a suction direction of the blower are provided.

[0006]

In the hot air circulating furnace according to the present invention, the operation of the discharge direction switching damper causes the discharge air of the two-way discharge blower to be discharged from one of the discharge ports and the other discharge port, whichever is more desirable, so that the hot air circulation path is formed. It can be supplied to the open end of the blower by opening and closing the suction direction switching damper so that the open end of the hot air circulation path on the opposite side to the discharge side communicates with the suction port of the blower. The hot air circulation direction can be switched without changing the rotation direction of the motor.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the figure, reference numeral 1 denotes a furnace body, 2 denotes a charging port, 3 denotes an extraction port, and 4 denotes a heart roll for transporting the workpiece W. Reference numeral 5 denotes a processing chamber, a reference numeral 6 denotes a hot air circulation path communicating with the processing chamber 5 at both ends of the furnace 1, and a reference numeral 7 denotes a heating radiant tube. A two-way discharge type blower 20 (hereinafter simply referred to as a blower 20) is inserted and installed at a middle portion of the hot air circulation path 6 in the furnace length direction. The casing 21 of the blower 20 has the same width as the width of the hot air circulation path 6 (size in the furnace width direction), and one discharge port 23 has an open end of the hot air circulation path 6 from the furnace inlet side to the blower 20. 6a, the other discharge port 24
Is connected to the open end 6b of the hot air circulation path 6 extending from the furnace outlet side to the blower 20 via ducts 8 and 9, respectively.

[0008] Reference numeral 10 denotes an intake duct which communicates the open ends 6a and 6b. An intake port 22 of a blower 20 is opened in the intake duct 10. Reference numerals 11 and 12 denote suction direction switching dampers whose bases are fixed to rotating shafts 13 and 14 extending in the furnace width direction along the lower edges of the discharge ports 23 and 24 of the blower 20, and these rotating shafts 13 and 14 are provided. Are rotationally driven by an air cylinder (not shown), whereby the intake duct 1
0 is opened and closed at both ends. Reference numerals 15 and 16 denote baffles provided at both ends of the furnace body 1 as needed for circulating hot air rectification, which are of a bogie type, but may be of other types.

The blower 20 has a built-in discharge direction switching damper, and its detailed structure will be described with reference to FIGS. In the figure, reference numeral 21 denotes a case made of a steel plate, which has a flat duct shape, and discharge ports 23 and 24 are formed at both ends thereof. Reference numeral 25 denotes an impeller built in the center of the casing 21. The impeller for the Shirotsu Kofan has a large number of shallow curved blade plates 25c fixed between an upper disk 25a and a lower ring 25b. A drive shaft 26 fixed to the disk 25a is rotatably supported on the casing 21 by bearings 27 and 27, and the drive shaft 26 is chain-driven by a motor 28. Reference numeral 22 denotes a suction port provided at the center of the lower plate of the casing 21 for supplying suction air into the impeller 25 through the ring 25b. 29
Is a heat insulating material for covering the outer peripheral surfaces of the casing 21 and the intake duct 10.

The casing 21 is defined by spirally curved side walls 31 and 41, and spiral chambers 32 and 42 which are 180 ° out of phase around the center of the impeller 25 are formed. The spiral chambers 32 and 42 have a rectangular cross section whose sectional area gradually increases in the discharge direction. The spiral chamber 32 is located at the discharge port 23, the spiral chamber 42 is located at the discharge port 24, and
Each is in communication. In the middle part of the spiral chambers 32 and 42, openings 33 and 43 each having a rectangular shape in front are formed on outer side walls 31 and 41 forming the spiral chambers.
The casing 21 is provided so as to fully open between the upper plate and the lower plate.

Reference numerals 34 and 44 denote these openings 33, 4
3 is a discharge direction switching damper that opens and closes from the inside of the spiral chamber.
Is formed to have a shape of a hollow wing plate which is curved so as to form a part thereof. The discharge direction switching dampers 34 and 44 are fixed to rotating shafts 35 and 45 extending in parallel with the downstream edges 33a and 43a of the openings 33 and 43, respectively. Rotating shaft 3
The upper and lower parts 5 and 45 are rotatably supported by bearings 30 and 30 through the casing 21 and the levers 36 and 46 fixed to the upper ends thereof are connected to the air cylinders 37 and 47.
The air cylinders 37 and 47 drive the discharge direction switching dampers 34 and 44 to rotate.

The distal end edges of the discharge direction switching dampers 34 and 44, which are driven to rotate in the opening closing direction,
The tip edges of the ejection direction switching dampers 34, 44, which are in contact with the upstream edges of the nozzles 3, 43 and are driven to rotate in the opening direction, contact the inner side walls 41, 31 to form the spiral chambers 32, 42.
Is pivoted to a position where it is closed at the intermediate portion. Reference numerals 38 and 48 denote guide plates which reduce the discharge air from the openings 33 and 43 with little loss.
It is for guiding to each part.

Next, a hot air circulating furnace (aging treatment furnace) having the above configuration.
Prior to the description of the hot air circulation direction switching method at 50, the operation of the blower 20 will be described first. In order to blow air only from the discharge port 23 in the blower 20, as shown in FIG. 2, the discharge direction switching damper 34 is driven by the air cylinder 37 to close the opening 33, while the air cylinder 4
7 drives the discharge direction switching damper 44 to open the opening 43.
And the spiral chamber 42 is closed at the middle part. As a result, the discharge air from the spiral chamber 42 reaches the discharge port 23 through the normal route, while the discharge air from the spiral chamber 42 is prevented from flowing to the discharge port 24 by the discharge direction switching damper 44, and Since it flows out from the part 43 and flows to the discharge port 23, the entire amount of the compressed air blown by the impeller 25 is discharged from the discharge port 23.

In order to switch the blowing direction and blow air only from the discharge port 24, the opening and closing directions of the discharge direction switching dampers 34 and 44 may be reversed. That is, as shown in FIG.
The opening 43 is closed by the discharge direction switching damper 44, the opening 33 is opened by the discharge direction switching damper 34, and the spiral chamber 32 is closed at the middle. As a result, the discharge air from the swirl chamber 42 passes through a normal route to reach the discharge port 24, while the discharge air from the swirl chamber 32 passes through the opening 33.
And flows to the discharge port 24, and the entire amount of the compressed air blown by the impeller 25 is discharged from the discharge port 24.

Since the discharge direction of the blower 20 can be switched as described above, the discharge direction switching dampers 34 and 44 are rotated to operate the discharge port 23 shown in FIG.
When the suction direction switching dampers 11 at both ends of the intake duct 10 are turned to the closed state and the suction direction switching damper 12 is turned to the open state as shown in FIG. The hot air sucked from the open end 6b through the intake duct 10 flows from the discharge port 23 to the open end 6a.
The hot air circulates in the workpiece storage chamber 5 in the direction of arrow X to heat the workpiece W.

In order to reverse the hot air circulation direction, the discharge direction switching dampers 34 and 44 and the suction direction switching dampers 11 and 12 are respectively rotated while the impeller 25 and the motor 28 are rotated in the same direction. Is rotated in the direction opposite to that of FIG.
Distribute in the direction.

In the above embodiment, the total air volume accelerated and pressurized by the impeller 25 merges and is discharged from one of the discharge ports, so that the blower has a small size and high efficiency and requires less power consumption. While having great advantages, it is also possible to use a conventional two-way discharge type blower which does not have the openings 33 and 43 in the side wall of the above-mentioned volute chamber (and therefore does not have the discharge direction switching dampers 34 and 44). . In this case, the suction direction switching damper 11 is rotated to a position where the discharge port 23 is closed when the intake duct 10 is opened, and the suction direction switching damper 12 is rotated to a position where the discharge port 24 is closed when the intake duct 10 is opened. It may be used as a dual-purpose damper having both the suction direction switching and the discharge direction switching.

Further, as shown in FIG. 5, a normal type bidirectional discharge blower 60 having no openings 33 and 43 is provided.
Ejection direction switching dampers 63, 6
Alternatively, the intake duct 65 may be provided with suction direction switching dampers 66 and 67 that are separate from them. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals as in FIG.

The present invention is not limited to the above embodiments. For example, other types of blowers may be used as the two-way discharge type blower. Further, the installation position of the two-way discharge type blower does not necessarily have to be at the longitudinal center position of the hot air circulation path. The present invention is also applicable to a hot air circulation furnace other than the aging furnace.

[0015]

As explained above, according to the present invention,
The switching of the hot air circulation direction can be quickly and easily performed only by operating the damper without performing the forward / reverse switching of the blower, and there is no loss of each part due to repeated forward / reverse rotation of the blower and loss of time and power. In addition, since the blower is installed in the middle of the hot air circulation path, the furnace length can be shortened.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a hot-air circulation furnace showing one embodiment of the present invention.

FIG. 2 is a horizontal sectional view of the two-way discharge type blower 20 in FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a horizontal sectional view showing a discharge direction switching state of the two-way discharge type blower of FIG. 2;

FIG. 5 is a longitudinal sectional view of a hot air circulating furnace showing another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing an example of a conventional hot air circulation furnace.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Furnace body, 5 ... Processing object accommodation room, 6 ... Hot air circulation path, 6a
... open end, 6b ... open end, 10 ... intake duct, 11
... Suction direction switching damper, 12 ... Suction direction switching damper, 2
0 ... bidirectional discharge type blower, 21 ... casing, 22 ... suction port, 23 ... discharge port, 24 ... discharge port, 25 ... impeller, 2
8 motor, 31 side wall, 32 spiral chamber, 33 opening, 34 discharge direction switching damper, 41 side wall, 42 spiral chamber, 43 opening, 44 discharge direction switching damper, 50
... hot air circulation furnace, 60 ... bidirectional discharge type blower, 61 ... discharge port, 62 ... discharge port, 63 ... discharge direction switching damper, 64 ...
Discharge direction switching damper, 65: intake duct, 66: suction direction switching damper, 67: suction direction switching damper

Claims (1)

(57) [Claims] 1. A hot-air circulating furnace having a hot-air circulating path communicating with an object-receiving chamber at both ends in a longitudinal direction of a furnace body, wherein a two-way discharge type blower is installed at an intermediate portion of the hot-air circulating path. One outlet of the blower is connected to an open end of a hot air circulation path from one end of the body to the blower, and the blower is connected to an open end of a hot air circulation path from the other end of the furnace body to the blower. A discharge direction switching damper for connecting a suction port of the blower to an intake path communicating with the both open ends and switching a discharge direction of the blower, and the blower provided in the intake path. And a suction direction switching damper for switching the suction direction of the hot air.