JP3658527B2 - Axial flow blower and air separator used therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an axial blower, and more particularly to an axial blower equipped with an air separator that is operated in a region close to a surging region.
[0002]
[Prior art]
Examples of an axial blower equipped with an air separator for improving low flow characteristics are described in Japanese Utility Model Laid-Open No. 3-87900 and Japanese Patent Laid-Open No. 9-25898. The air separator described in Japanese Utility Model Publication No. 3-87900 includes an outer wall, a side wall, and a rectifying vane, and the position of the inner edge of the rectifying vane is set to be substantially the same as the inner diameter position of the casing. This air separator has an opening that becomes the inlet of the flow path from the upstream side of the moving blade to the vicinity of the center of the axial length of the moving blade, and an opening that becomes the outlet of the flow path upstream of the moving blade inlet portion. Is formed. The rectifying vane is installed at the inlet of the flow path, and the inner edge of the rectifying vane is located at the inlet opening. This rectifying vane has a warp in the direction opposite to the rotating direction of the moving blades in order to remove a circumferential component of the air flow from the tip of the moving blades toward the inlet opening of the flow path of the air separator.
[0003]
When an axial blower without an air separator is operated at a low flow rate, a backflow airflow is generated in a small backflow region of the inter-blade channel on the tip side of the moving blade. As this gradually grows, the moving blades become stalled, which limits the operating range of the axial flow fan. However, by providing the air separator, the backflow airflow generated on the tip side of the rotor blade flows into the flow path from the inlet opening of the air separator by centrifugal force. The airflow that flows into the flow path of the air separator becomes an airflow that does not have a circumferential component due to the rectifying vanes in the flow path, and merges with the main flow that flows between the moving blades by flowing out from the outlet opening upstream of the moving blades. To do. That is, if the backflow at the tip of the moving blade is removed, the operating range of the axial flow fan in the low flow rate region can be expanded.
[0004]
In this conventionally used axial blower with air separator, the position of the inner edge of the rectifying vane extends to almost the same position as the inner diameter position of the casing, so the flow flowing from the blade to the air separator interferes with the rectifying vane. The pressure field formed around the rotor blades and the rectifying vane may interfere with each other to generate noise. Further, since the rectifying vanes are installed only at the inlet portion or the outlet portion of the air separator, the circumferential component of the airflow passing through the air separator cannot be removed much. As a result, there has been a problem that the effect of expanding the operating range of the air separator is reduced or the effect of increasing the pressure is reduced.
[0005]
In order to solve such a problem, in the axial blower described in JP-A-9-25898, a hub is rotated together with a rotating shaft, and a moving blade is provided on the outer periphery of the hub. A plurality of stationary blades and an air separator formed in an annular radial projection are provided on the downstream side of the moving blade. In this air separator, a flow path is formed by two side wall members, an outer wall member that connects between the side wall members, and a rectifying vane so as to guide the flow on the tip side of the blade to the upstream side of the blade. . The inner edge of the rectifying vane recedes radially outward from the inner diameter of the casing at the inlet side of the flow path.
[0006]
An example of removing deposits deposited on a blade by jetting water from the nozzle to the blade when the axial blower is used in an air flow environment with a large amount of deposits is disclosed in JP-A-6-10897. Yes.
[0007]
[Problems to be solved by the invention]
The axial fan described in JP-A-9-25898 includes an air separator having a rectifying vane. And since this rectification | straightening vane is arrange | positioned from the inlet part of an air separator to the exit part, the operating range of an axial fan can be expanded with an air separator, and it is also possible to prevent the fall of the pressure rise in an axial fan. . Moreover, since the inner edge position of the rectifying vane is retracted to the outer diameter side, interference between the outflow air flow and the rectifying vane can be mitigated, and noise can be reduced.
[0008]
However, in the axial fan described in this publication, when a fluid containing a large amount of dust and mist is a working fluid, it is considered that dust or the like adheres to and accumulates on the casing channel surface and the circulation channel. Absent. When working fluid containing a large amount of dust and mist flows into the axial blower, these may adhere and accumulate on the wall surface of the flow path, hindering the flow, reducing efficiency, and causing an unstable phenomenon in the flow.
[0009]
Further, the one described in Japanese Patent Laid-Open No. 6-10897 does not include an air separator. Therefore, when the operating range is expanded and the pressure is increased by the air separator, the performance of the air separator is reduced by dust or mist. It is not considered to do.
[0010]
The present invention has been made in view of the above-described problems of the prior art, and its purpose is to stabilize an axial blower equipped with an air separator or an air separator used in an axial blower with a simple device regardless of the type of working gas. To drive. Another object of the present invention is to expand the operating range of the axial blower and reliably increase the pressure.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the first feature of the present invention is that a hub 2 that rotates together with a rotatable rotating shaft, and a plurality of sheets that are provided on the outer peripheral side of the hub and spaced in the circumferential direction. In the axial blower including the rotor blade 1 and the air separator 5 formed to extend radially outward in an annular shape, the air separator connects a plurality of partial cylindrical members in the circumferential direction. An outer peripheral wall member 4a, a hollow ring-shaped member 6 positioned on the inner peripheral end side of the outer peripheral wall member and having a circular cross section, and first and second plate-shaped members 14 and 15 fixed to the ring-shaped member. The air separator is provided with an adhering deposit removing means capable of removing adhering deposit adhering to or depositing on the air separator during operation of the axial blower, and the adhering deposit removing means is a hollow member of the ring-shaped member. A pipe 8 for guiding a high-pressure fluid into the interior space of A plurality of ejection holes 7 are formed in the ring-shaped member .
[0012]
Preferably , a plurality of ejection holes are formed in at least one of the first plate member and the second plate member, or a plurality of ejection holes are formed in the outer peripheral wall member, and a high-pressure fluid is formed in the ejection holes. Flexible piping that guides the connection .
[0014]
In order to achieve the above object, a second feature of the present invention is an air separator that is provided on the outer peripheral side of a moving blade of an axial-flow fan and extends annularly outward in the radial direction. An outer peripheral wall member connected in a circumferential direction, a hollow ring-shaped member having a plurality of holes and having a circular cross section located on the inner peripheral end side of the outer peripheral wall member, and fixed to the ring-shaped member First and second plate-like members, and attached deposit removing means capable of removing attached deposits that adhere to or deposit on the air separator during operation of the axial blower, the attached deposit removing means includes the ring A pipe for guiding a high-pressure fluid into the hollow internal space of the member .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view of an embodiment of an axial blower according to the present invention, FIG. 2 is an enlarged view of an air separator used in the axial blower shown in FIG. 1, and FIG. 3 is shown in FIG. It is an axis perpendicular cross section of an air separator part.
[0018]
In the axial blower 17 according to one embodiment of the present invention, a rotor is disposed between the outer cylinders 10a to 10c and the inner cylinder 12, and the pressure of the gas sucked from the suction casing 9 is increased and discharged from the diffuser 11 to the demand source. doing. A plurality of moving blades 1 are arranged on the outer periphery of the hub 2 forming a part of the inner cylinder at intervals in the circumferential direction. The rotor formed by a part of the moving blade 1 and the inner cylinder 12 is rotationally driven by an electric motor (not shown) provided in the inner cylinder 12 or outside the machine. When the moving blade 1 rotates, the air sucked from the suction casing 9 is pressurized and discharged to the diffuser 11, but at that time, noise may be generated due to the backflow generated on the tip side of the moving blade 1. Therefore, an air separator 5 protruding in a ring shape in the circumferential direction is formed on the outer periphery of the outer cylinders 10a and 10b where the rotor blade 1 is located.
[0019]
In order to convert the kinetic energy imparted to the gas by the moving blade 1 into pressure energy, a plurality of stationary blades arranged at intervals in the circumferential direction may be disposed on the downstream side of the moving blade 1. . A plurality of stays 13 a to 13 d are attached between the outer cylinders 10 a to 10 c and the inner cylinder 12 in order to hold the rotating portion of the axial flow fan configured as described above in the outer cylinders 10 a to 10 c.
[0020]
The air separator 5 whose details are shown in FIGS. 2 and 3 is located on the upstream side of a casing 10 a (10 b) disposed in the outer circumferential direction of the moving blade 1 with a slight gap from the tip of the moving blade 1. More precisely, the middle part of the tip of the rotor blade 1 is the boundary between the casing 10a (10b) and the air separator 5. The air separator 5 is formed in a ring shape by the outer wall 4a and the side walls 4b and 4c. The outer wall 4a of the air separator 5 has a partially arcuate cross-sectional shape perpendicular to the axis, and one end side thereof extends to the inner cylinder 12 side. The arc-shaped outer wall 4a functions as a rectifying vane.
[0021]
As shown in FIG. 2, the air separator 5 forms a flow path 5 c from the upstream side of the moving blade 1 to the vicinity of the center of the axial blade length of the moving blade 1. That is, the reverse flow generated at the tip of the moving blade 1 flows into the flow path 5 of the air separator 5 from the opening 5 b of the air separator 5 and flows out from the opening 5 a provided on the upstream side of the moving blade 1. The radial position of the outer wall 4a is such that the inflow 5b side is closer to the inner diameter side than the outflow 5a side.
[0022]
In order to separate the inflow portion and the outflow portion of the reverse flow into the air separator 5, the pipe 6 is provided in the circumferential direction in the flow path of the air separator 5, from the same radial position as the moving blade tip position to the outer diameter side position. Is arranged. On the downstream side of the pipe 6, plate-like members 14 and 15 are disposed in contact with the pipe 6. The shape formed by the pipe 6 and the plate-like members 14 and 15 has a cross-sectional shape that approximates the wing shape.
[0023]
In this embodiment, the cross-sectional shape perpendicular to the axis of the outer wall 4a of the air separator 5 is an arc shape, and the inner diameter of the outer wall 4a located at the inlet opening 5b portion of the flow path 5c is larger than the inner diameter position of the casings 10a and 10b. Is located. Thereby, the effect of removing the circumferential component of the backflow can be increased, and the effect of expanding the operating range of the air separator and the decrease in the pressure rise can be prevented.
[0024]
By the way, if a large amount of dust and mist is contained in the working fluid, these adhere to and accumulate on each part of the axial blower during long-term use, causing a decrease in performance and an increase in noise. In a conventional axial blower that does not use an air separator, pressurized water or the like is sprayed onto a moving blade, a stationary blade, or a casing when operation is stopped to prevent a decrease in performance or an increase in noise. However, in recent years when installation conditions for axial fans and performance maintenance conditions for axial fans have become strict, it is required to prevent adhesion and accumulation of dust and mist in the axial fan even during operation. .
[0025]
In view of this, in the present invention, the air separator near the most upstream position of the axial blower is provided with means for preventing adhesion and accumulation of dust and mist that do not interfere with operation. Specifically, a plurality of ejection holes 7 are provided in a ring-shaped pipe 6 included in the air separator 5, and a high-pressure fluid is guided to the ring-shaped pipe 6 by a pipe 8. As the high-pressure fluid, pressurized water is the simplest, but high-pressure gas or the like may be used. However, it is limited by the type of fluid handled by the axial blower. Moreover, it must be higher than the flow path pressure of the axial blower.
[0026]
As shown in FIG. 3, since the outer wall 4a of the air separator is formed by continuously forming a semicircular member having a substantially semicircular cross-section in the circumferential direction, the ejection hole 7 is formed corresponding to each semicircular portion. Provide. The position of the ejection hole 7 is preferably the arc center of the semicircular outer wall. In addition, it is desirable to provide the ejection hole 7 also in the plate-like member 14. In this case, the position of the ejection holes 7 is set to the same circumferential position as the ejection holes 7 provided in the ring-shaped pipe 6 or the same circumferential pitch as the circumferential pitch of the ejection holes 7 provided in the ring-shaped pipe 6. It is desirable.
[0027]
As described above, in the present embodiment, since the inside of the ring-shaped pipe included in the air separator is a cavity, a high-pressure fluid is guided into the pipe, and a plurality of jet holes are formed in the pipe. It is possible to prevent mist and dust from adhering to and accumulating on the air separator during operation with a simple configuration.
[0028]
4 and 5 show another embodiment of the present invention. The difference between the embodiment shown in FIGS. 4 and 5 and the embodiment shown in FIGS. 2 and 3 is that a high-pressure fluid ejection hole 7 is provided directly on the outer wall 4a of the air separator. According to the present embodiment, since the ejection holes are provided directly on the outer wall where dust and mist are expected to adhere most, the effect of removing dust and mist is great. Although the description is simplified in FIG. 5, in this embodiment, it is necessary to provide a high-pressure fluid introduction path 16 corresponding to each ejection hole 7 on the outer wall 4 a. In this case, flexible piping is preferable as the introduction path 16 in terms of construction.
[0029]
The positions and the number of the ejection holes shown in the above embodiments are exemplary, and it goes without saying that the position and the number may be increased or decreased according to the type and operating environment of the working gas of the axial blower. Moreover, as shown in FIG. 1, it is natural that it may be provided at a position other than the air separator.
[0030]
【The invention's effect】
As described above, according to the present invention, the air separator provided in the axial blower is provided with the removing means capable of removing the deposits or the like adhered or deposited on the air separator even during operation. The efficiency of the axial blower and the air separator can be prevented from being reduced. Further, the pressure increase does not decrease.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an embodiment of an axial blower according to the present invention.
FIG. 2 is an enlarged cross-sectional view of an air separator portion of the axial blower shown in FIG.
3 is a cross-sectional view perpendicular to the axis of the air separator shown in FIG.
FIG. 4 is a longitudinal sectional view of another embodiment of the air separator.
5 is a cross-sectional view perpendicular to the axis of the air separator shown in FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Moving blade, 2 ... Hub, 4a ... Outer wall, 5 ... Air separator, 6 ... Ring-shaped member, 7 ... Injection hole, 8 ... Pipe, 9 ... Suction casing, 10a-10c ... Outer cylinder, 12 ... Inner cylinder, 13a to 13d ... stays, 14 ... plate-like members, 15 ... plate-like members, 16 ... flexible piping.

Claims (4)

A hub 2 that rotates together with a rotatable rotating shaft, a plurality of rotor blades 1 that are provided on the outer peripheral side of the hub and spaced in the circumferential direction, and annularly extend radially outward. In the axial blower provided with the air separator 5 formed as described above, the air separator is arranged on the outer peripheral wall member 4a in which a plurality of partial cylindrical members are connected in the circumferential direction, and on the inner peripheral end side of the outer peripheral wall member. A hollow ring-shaped member 6 having a circular cross-section and first and second plate-shaped members 14 and 15 fixed to the ring-shaped member, and a deposit deposited on or deposited on the air separator The air separator is provided with an adhering deposit removing means that can be removed during the operation of the flow blower, and the adhering deposit removing means has a pipe 8 for introducing a high-pressure fluid into the hollow internal space of the ring-shaped member, and the ring this formed a plurality of jet holes 7 Jo member Axial blower according to claim. The axial blower according to claim 1, wherein a plurality of ejection holes are formed in at least one of the first plate member and the second plate member . The axial blower according to claim 2, wherein a plurality of ejection holes are formed in the outer peripheral wall member, and a flexible pipe for guiding a high-pressure fluid is connected to the ejection holes . An air separator provided on the outer peripheral side of a moving blade of an axial blower and extending annularly outward in the radial direction, and an outer peripheral wall member in which a plurality of partial cylindrical members are connected in the circumferential direction, and the outer periphery A hollow ring-shaped member with a plurality of holes formed and circular in cross section located on the inner peripheral end side of the wall member, first and second plate-shaped members fixed to the ring-shaped member, and attached to the air separator An adhering deposit removing means capable of removing adhering accumulated deposit during operation of the axial blower, and the adhering deposit removing means has a pipe for guiding a high-pressure fluid to a hollow internal space of the ring-shaped member. An air separator for an axial-flow fan.

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