JP3019499B2 - Bi-directional discharge type centrifugal blower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way discharge type centrifugal blower, and more particularly to a two-way discharge type centrifugal blower whose discharge direction can be switched.

[0002]

2. Description of the Related Art In general, as a double discharge centrifugal blower, two spiral chambers having a rectangular cross section are provided around the center of an impeller.
A double casing type arrangement having a phase shift of 0 ° is often used. Since this blower blows air continuously in two directions from two discharge ports, for example, when used as a hot air circulation fan in a heat treatment furnace for a long material, two blowers are required to reverse the hot air circulation direction. The outlet must be opened and closed alternately by a damper, and only one swirl chamber is used, reducing the air volume by half and reducing the efficiency. Was.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a small, high-efficiency, double-discharge centrifugal blower capable of switching the discharge direction.

[0004]

SUMMARY OF THE INVENTION A two-way discharge centrifugal blower according to the present invention comprises a two-way discharge centrifugal blower in which two spiral chambers each having a rectangular cross section are arranged 180 degrees out of phase around the center of the impeller. In the blower, an opening is provided on the outer peripheral side wall of each of the spiral chambers to communicate one of the spiral chambers and the discharge port of the other spiral chamber, and the opening is opened and closed, and a part of the outer peripheral side wall is provided when the opening is closed. Is formed so as to be rotatable around an axis extending along the downstream edge of the opening, and the swirl is formed by the damper rotated inside the swirl chamber when the opening is opened. The room is closed.

[0005]

In the two-way discharge type centrifugal blower of the present invention, if the opening of the side wall of the spiral chamber is closed by the damper,
The air or gas pressurized and accelerated by the impeller flows in the spiral chamber and flows out to the discharge port. If the damper is rotated to open the opening and close the spiral chamber,
The air or gas flows out of the opening and flows out to a discharge port communicating with the other volute.

Accordingly, if the opening of one of the spiral chambers is closed, the opening of the other spiral chamber is opened, and the other spiral chamber is closed, the total amount of air discharged from the impeller becomes one of the spirals. It is discharged from the discharge port of the chamber. If the opening and closing of each opening is reversed and one of the spiral chambers is closed, the entire amount of the discharge air is discharged from the discharge port of the other spiral chamber, and the discharge direction can be switched.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the drawing, reference numeral 1 denotes a case made of a steel plate, which has a flat duct shape, and discharge ports 2 and 3 are formed at both ends thereof. Reference numeral 4 denotes an impeller incorporated in the center of the casing 1 and has a plurality of shallowly curved impellers 7 fixed between an upper disk 5 and a lower ring 6 for a Shirotsuko fan. The drive shaft 8 fixed to the disk 5 is
And is rotatably supported on the casing 1 by the drive shaft 8.
Is driven by a motor 10 in a chain drive. 1
Reference numeral 1 denotes a suction port provided at the center of the lower plate 12 of the casing 1 for supplying suction air into the impeller 4 through the ring 6.

The inside of the casing 1 is defined by spirally curved side walls 21 and 31 and spiral chambers 22 and 32 which are 180 ° out of phase around the center of the impeller 4.
Are formed. Each of the spiral chambers 22 and 32 has a rectangular cross section whose sectional area gradually increases in the discharge direction. The spiral chamber 22 communicates with the discharge port 2, and the spiral chamber 32 communicates with the discharge port 3. The outer side walls 21 and 31 forming these spiral chambers are provided in the middle of the spiral chambers 22 and 32.
Openings 23 and 33 each having a rectangular front shape are provided so as to fully open between the upper plate 13 and the lower plate 12 of the casing 1.

The openings 24 and 34 are provided with these openings 23, 3
3 is a damper which opens and closes from the inside of the spiral chamber, and has a hollow blade shape curved so as to form a part of the spiral side walls 21 and 31 with these openings closed. Damper 2
4, 34 are the downstream edges 23 of the openings 23 and 33.
a, 33a are fixed to rotating shafts 25 and 35, respectively, which extend in parallel to the shafts 33a. The rotating shafts 25 and 35 penetrate the casing 1 and are rotatably supported at upper and lower portions by bearings 14 and 14, and are fixed to upper ends thereof with levers 26 and 36.
Are connected to the piston rods of the air cylinders 27 and 37, and the dampers 24 and 34 are driven to rotate by the air cylinders 27 and 37.

The tip edges of the dampers 24, 34 pivotally driven in the opening closing direction abut against the upstream edges of the openings 23, 33, and the dampers 24 pivotally driven in the opening direction. , 34 are in contact with the inner side walls 31, 21 so as to rotate to a position where the swirl chambers 22, 32 are closed at an intermediate portion. Reference numerals 28 and 38 denote guide plates for guiding the discharge air from the openings 23 and 33 to the discharge ports 2 and 3 with little loss.

In the two-way discharge type centrifugal blower 15 having the above-described structure, in order to blow air only from the discharge port 2, as shown in FIG. The damper 34 is driven by the cylinder 37 to open the opening 33 and close the spiral chamber 32 at the middle. As a result, the discharge air from the spiral chamber 22 reaches the discharge port 2 through a normal route, while the discharge air from the spiral chamber 32 is prevented from flowing out to the discharge port 3 by the damper 34, and is discharged from the opening 33. Since it flows out and flows to the discharge port 2, the entire amount of the compressed air blown by the impeller 4 is discharged from the discharge port 2.

Next, in order to switch the air blowing direction and blow air only from the discharge port 3, the opening and closing directions of the dampers 24 and 34 may be reversed. That is, as shown in FIG. 3, the opening 33 is closed by the damper 34 by the air cylinders 37 and 27, and the opening 2 is closed by the damper 24.
3 is opened and the volute 22 is closed at the middle. As a result, the air discharged from the swirl chamber 32 is reduced to a normal flow rate.
To the discharge port 3, while the discharge air from the swirl chamber 22 flows out of the opening 23 and flows to the discharge port 3, and the impeller 4
Is discharged from the outlet 3 in its entirety.

The switching of the discharge direction by the opening and closing of the dampers 24 and 34 can be performed while the impeller 4 is rotating or stopped.
It is particularly preferable that the discharge direction be changed during the rotation because the discharge direction can be switched in a short time without starting and stopping the impeller 4 and the motor 10.

The present invention is not limited to the above embodiment. For example, the openings 23 and 33 may be provided further downstream than the above embodiment. The shape of each part of the casing 1 may be other than the above, such as reducing the width of the discharge ports 2 and 3 as shown by a chain line 16 in FIG. Further, in the above embodiment, the rotation shafts 25 and 35 of the damper are connected to the openings 23 and 3.
3 are provided close to the downstream side edge portions 23a, 33a. However, when dampers 24, 34 having an elongated triangular cross section are used as shown in FIG.
a, 33a. In the drawing, the same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals.

Further, the opening / closing drive of the dampers 24 and 34 may be performed by a driving device other than the above-described air cylinder. In particular, a driving device including one driving machine and an interlocking mechanism such as a link mechanism and a gear train is used. It is preferable to use the two dampers to drive the two dampers in the opening / closing reverse direction so that the discharge direction can be quickly and reliably switched. In addition to this invention, in addition to Shirotsukofan (multi-blade fan), radial fan,
It can also be applied to a centrifugal blower such as a Turbofan.

[0016]

As explained above, according to the present invention,
By rotating the dampers provided at the two openings, the discharge direction can be easily switched, and the openings and the dampers are provided on the side wall of the spiral chamber, so that the entire blower has a simple and compact structure. In addition, since the total amount of air flowing through both swirl chambers is used as the discharge air, the blower becomes smaller and more efficient than when using only the discharge air from one of the swirl chambers of the two-way discharge type blower. Less.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view of a two-way discharge type centrifugal blower showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line AA of FIG.

FIG. 3 is a horizontal sectional view showing a state of switching the discharge direction of the centrifugal blower of FIG. 1;

FIG. 4 is a view corresponding to FIG. 1, showing another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 casing 2 discharge port 3 discharge port 4 impeller 11 suction port 15 bidirectional discharge centrifugal blower 21 side wall 22 spiral chamber 23 opening 23 a downstream side edge 24 damper 25 rotation axis 26 lever 27 air cylinder 31 side wall 32 Spiral chamber 33 Opening 33a Downstream edge 34 Damper 35 Rotating shaft 36 Lever 37 Air cylinder

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-14896 (JP, A) JP-A-63-189698 (JP, A) JP-A-62-113898 (JP, A) 22498 (JP, U) Japanese Utility Model Showa 58-30116 (JP, U) Japanese Utility Model Showa 50-49240 (JP, U) Japanese Utility Model Showa 58-46896 (JP, U) Japanese Patent Publication No. 63-10319 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) F04D 29/40-29/56

Claims (1)

(57) [Claims] 1. A two-way discharge centrifugal blower in which two spiral chambers each having a rectangular cross section are arranged with a phase difference of 180 ° around the center of an impeller. An opening communicating with the discharge port of the other spiral chamber is provided, and a damper that opens and closes the opening and forms a part of the outer peripheral side wall when the opening is closed is formed along the downstream edge of the opening. A bidirectional discharge blower, wherein the blower chamber is rotatably supported about an axis extending therethrough, and the swirl chamber is closed by the damper which is turned into the swirl chamber when the opening is opened. .