JP3795222B2 - Centrifugal blower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a centrifugal blower including a spiral casing used for air conditioning equipment and ventilation equipment.
[0002]
[Prior art]
FIG. 4 is a diagram showing a basic configuration example of this type of conventional centrifugal blower. In the figure, the centrifugal blower B includes a casing 10, and an impeller 11 is arranged in a spiral chamber of the casing 10. In the centrifugal blower B having such a configuration, the center line 12 of the discharge port 10a of the casing 10 and the center line 13 of the spiral of the casing 10 at the discharge port 10a are parallel to each other.
[0003]
[Problems to be solved by the invention]
In the conventional centrifugal blower, when a bent duct is connected immediately after the casing 10, there is no problem as long as the bent direction of the bent duct 14 is the same as the rotational direction 15 of the impeller as shown in FIG. When the bending direction of the bending duct 14 is opposite to the rotation direction 15 of the impeller as in FIG. 6, there is a problem that the pressure loss increases and a predetermined air volume cannot be obtained.
[0004]
Although it is desirable to avoid bending the duct immediately after the blower, problems such as piping layout and duct piping space may cause the duct to be bent immediately after the blower.
[0005]
In order to cope with this, in the case of a centrifugal blower, two types of impellers and casings are prepared for clockwise rotation and counterclockwise rotation, respectively. As shown in (a) to (f) of FIG. 7 as standard, the discharge direction 16 is prepared in six types, and a method is used that prevents the occurrence of a large pressure loss by properly using the direction of duct bending. ing. Further, since the discharge direction other than that shown in FIG. 7 is also required depending on the arrangement of the ducts, there are many types of discharge directions. In FIG. 7, B is a centrifugal blower, 17 is a motor for driving the centrifugal blower B, and 18 is a base.
[0006]
For this reason, the impeller and the casing of the centrifugal blower B must have two types of blowers of the same size and the same performance, and at least six types must be prepared as finished products of the centrifugal blower B. There was a problem in terms of production and inventory. In addition, there are cases in which the discharge direction cannot be changed unless the casing and impeller are replaced, such as when changing the discharge direction such as duct layout change at the installation site. There was also the complexity of having to choose.
[0007]
The present invention has been made in view of the above points, and an object thereof is to provide a centrifugal blower having a configuration in which an impeller and a casing are prepared only for one-way rotation and the discharge direction can be reduced.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention described in claim 1 is a centrifugal blower having a configuration in which an impeller is arranged in a spiral casing, and the entire spiral of the casing is arranged with respect to the center line of the discharge port of the casing. The structure is characterized in that the center of the discharge port of the casing is made closer to the center of the suction port by rotating the impeller by a predetermined angle.
[0009]
The invention described in claim 2 is characterized in that, in the centrifugal blower described in claim 1, the angle at which the spiral is rotated in the rotation direction of the impeller is in the range of 5 ° to 35 °.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a basic configuration of a centrifugal blower according to the present invention. In FIG. 1, 1 is a casing, 2 is a center line of the discharge port 1a of the casing 1, 3 is a center line of the spiral of the casing 1, and 4 is an impeller. As shown in the figure, the centrifugal blower A is configured by discharging the entire spiral of the casing 1 and rotating it in the rotational direction of the impeller 4 by a predetermined angle θ with respect to the center line 2 of the opening 1a.
[0011]
Here, the angle θ is in the range of θ = 15 ° to 35 °. In the conventional centrifugal blower, as shown in FIG. 4, the center line 12 of the discharge port 10a and the center line 13 of the spiral are parallel, whereas in the present invention, the center line 3 of the spiral is discharged from the casing 1. The casing 1 is configured to rotate at an angle θ in the rotation direction of the impeller 4 around the center line 2 of the mouth 1a. As a result, the center of the discharge port 1a of the casing 1 approaches the center of the suction port as compared with the centrifugal blower having the conventional configuration. FIG. 2 is a comparative view superimposed on the centrifugal blower A according to the present invention shown in FIG. 1 and the conventional centrifugal blower B shown in FIG.
[0012]
In the centrifugal blower having the conventional configuration, the wind speed at the discharge port 10a of the casing 10 is increased on the outer peripheral side. Therefore, if there is a bend in the duct immediately after the discharge port, and if this bend is in the same direction as the rotation direction of the impeller 11, air flows along this bend, so a large pressure loss does not occur. When the direction is opposite to the rotation direction of the impeller, a large loss occurs due to the influence of the air in the fast flow portion. In general, considering the arrangement of pipes and blowers, it is often the case that the duct is bent immediately after the blower outlet, and this is unavoidable.
[0013]
As described above, the centrifugal blower of the present invention has a configuration in which the spiral centerline 3 of the casing 1 is rotated by the angle θ in the rotational direction of the impeller 4 to the centerline 2 of the discharge port 1a. The center of the discharge port 1a approaches the center of the suction port. As a result, the portion of the discharge port of the casing 1 where the wind speed is high approaches the central portion of the discharge port, and the duct immediately after the discharge port 1a of the casing 1 of the centrifugal blower is defined as the rotational direction of the impeller 4. Even if bent in the same direction, bent in the opposite direction, or straightened without bending, there is no significant difference in pressure loss. Therefore, it is sufficient to allow for the pressure loss of a normal bent duct.
[0014]
FIG. 8 shows a case where a straight measurement duct 101 is connected to a casing discharge port of a conventional centrifugal blower B, and a duct 102 bent in a direction opposite to the rotation direction of the impeller and a straight measurement duct downstream thereof. FIG. 9 is a diagram showing an example of a result of performing a performance (static pressure-air volume) test when 101 is connected, and FIG. 9 is a diagram showing how a straight measurement duct 101 is connected to the casing outlet of the centrifugal blower A of the present invention A case where a duct 102 bent in the direction opposite to the rotation direction of the impeller is connected and a straight measurement duct 101 is connected downstream thereof, and a case where a duct 103 bent in the same direction as the rotation direction of the impeller is connected. It is a figure showing an example of a result of performing a performance test when a straight measurement duct 101 is connected downstream.
[0015]
As shown in FIG. 8, in the conventional centrifugal blower B, compared to the case where a straight duct is connected to the casing discharge port, the pressure loss is caused when a duct bent in the direction opposite to the rotation direction of the impeller is connected. Becomes larger. On the other hand, in the centrifugal blower according to the present invention, as shown in FIG. 9, even when a straight duct is connected, a duct bent in the same direction as the impeller rotation direction or the opposite direction is connected. There is no big difference in loss.
[0016]
For this reason, conventionally, in the centrifugal blower B, it is general to select the rotation direction of the impeller 11 according to the bending direction of the duct immediately after the discharge port 10a of the casing 10. However, since the rotation direction of the impeller 11 of the blower is two types, even if the centrifugal blower has the same size and the same performance, the impeller 11, the casing 10, and other parts are used for clockwise rotation and counterclockwise rotation. Therefore, there is a problem that the types of production and stock increase as described above.
[0017]
On the other hand, in the centrifugal blower A according to the present invention, if the blower has the same size and the same performance, the impeller 4, the casing 1, and other parts may be made one type for clockwise or counterclockwise. Can reduce the types of production and inventory. Moreover, as a completed product of a centrifugal blower, it can reduce to four types as shown in FIG. 3, and it is not made into six types like the prior art example shown in FIG. Therefore, the problem of inventory space can be alleviated. In FIG. 3, 5 is a motor for driving the centrifugal blower A, and 6 is a base.
[0018]
In addition, the centrifugal blower A according to the present invention replaces the parts because the impeller 4, the casing 1, and other parts are one type even when the fan and duct arrangement is changed at the installation site and the discharge direction of the blower is changed. It is now possible to change the discharge direction without changing the discharge direction, so the discharge direction can be changed even after the inlet of the blower is blocked. It was.
[0019]
【The invention's effect】
As described above, according to the present invention, the following excellent effects can be expected.
Since the entire spiral of the casing is rotated by a predetermined angle in the rotation direction of the impeller with respect to the center line of the discharge port of the casing, and the center of the discharge port of the casing is brought close to the center of the suction port, the discharge port of the blower Immediately after the rotation of the impeller, there is no significant difference in pressure loss between the case where it is bent in the same direction and the case where a straight duct is used. There is no need to prepare, and one type can be obtained, and the types of production and stock can be reduced.
[0020]
In addition, as a finished product of the blower, this can reduce the conventional 6 types to 4 types, so the number of stocks can be reduced, selection errors can be reduced, and the direction of discharge at the installation site can be changed. Can be simplified compared to the conventional example.
[Brief description of the drawings]
FIG. 1 is a diagram showing a basic configuration example of a centrifugal blower of the present invention.
FIG. 2 is a diagram showing an example in which a centrifugal fan of the present invention and a conventional centrifugal fan are displayed in an overlapping manner.
FIG. 3 is a view showing types of finished products of the centrifugal blower of the present invention.
FIG. 4 is a diagram illustrating a basic configuration example of a conventional centrifugal blower.
FIG. 5 is a diagram showing a configuration in which a bending duct is connected in the same direction as the rotation direction of an impeller of a conventional centrifugal blower.
FIG. 6 is a diagram showing a configuration in which a bending duct in a direction opposite to the rotation direction of an impeller of a conventional centrifugal blower is connected.
FIG. 7 is a view showing types of finished products of a conventional centrifugal blower.
FIG. 8 is a diagram showing an example of a result of a performance test of a conventional centrifugal fan.
FIG. 9 is a diagram showing an example of a result of performance test of the centrifugal blower of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Casing 2 Centerline 3 of discharge port 1a Centrifugal centerline 4 Impeller

Claims (2)

In the centrifugal blower having a configuration in which the impeller is arranged in a spiral casing,
The entire spiral of the casing is rotated by a predetermined angle in the rotation direction of the impeller with respect to the center line of the discharge port of the casing, and the center of the discharge port of the casing is made closer to the center of the suction port. Centrifugal blower characterized by. In the centrifugal blower according to claim 1,
The centrifugal blower characterized in that an angle of rotating the spiral in the rotation direction of the impeller is in a range of 5 ° to 35 °.

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