JPS6215519Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a radial flow blower for a burner, which supplies air to an oil burner, a gas burner, or the like.

BACKGROUND OF THE INVENTION Burner radial flow blowers used in connection with oil burners or gas burners are designed to effectively cope with the large flow resistance experienced when the burner is first started, even at low flow speeds. Although it is necessary to have a high delivery pressure, the disadvantage of conventional radial blowers is that they create a circulating flow inside the blower, causing eddies, etc., and this phenomenon is particularly strong at low speeds, making it impossible to obtain high pressure. It was hot.

Means for Solving the Problems In this invention, in order to eliminate the drawbacks of the conventional method, a jiyama board is attached to the edge of the cutout for air inflow, and this jiyama board is attached to the impeller at the upstream edge of the cutout. The fan-shaped corner of the cutout is within the range of 45° to 240°, and the angle between the axis of the outlet passage and the upstream edge of the cutout is 0° to 135°.
The angle between the axis of the outlet passage and the upstream edge of the cutout portion is selected so that the angle between the axis of the outlet passage and the upstream edge of the cutout portion becomes smaller as the corner of the fan shape becomes larger.

Embodiment FIG. 1 is an end view of an embodiment of the radial blower of this invention, and FIG. 2 is a sectional view taken along line 2-2 in FIG. 10, from whose circumferential wall 11 an outlet passage 12 and two axial end walls 13,1
4 is growing. Inside the casing 10, one impeller 15 having a plurality of blades 16 from which one plate 17 extends is rotatably mounted. The outlet passage 12 extends generally tangentially to the impeller 15 as shown.
The blades 16 have an exit angle of at least 90°, and the outer peripheral surface of the impeller 15 is connected to the spiral wall 11 and the exit 1
2, that is, the part 11a is closest to the spiral wall 11, and the part 1
1a is at the smallest radial distance from the axis of the impeller 15. A gap 18 is formed between the walls 11 of the impeller 15 and the gap 18 surrounds the impeller 15 and communicates with the outlet 12.

The axial dimensions of the impeller are significantly smaller than the dimensions of the casing 10. In practice, it has been found that satisfactory results are obtained when the impeller 15 has dimensions within the range of 30 to 85% of the axially inner dimensions of the casing 10. The impeller 15 has a considerable axial clearance space between the end wall 13 and adjacent axial ends of the impeller 15, i.e. a central portion 19a adjacent to the open end of the impeller and a radially outer portion 19b. It is arranged inside the casing 10 so as to be able to do so.
Unlike the conventional blower, in this embodiment, the gap 18 and the spaces 19a, 19
No attempt has been made to prevent air flow between b and b, allowing such air flow to flow completely unimpeded.

The wall 13 has one circular opening through which the impeller can be removed. wall 13
is provided with a flat plate 20 which partially closes and closes the opening. The plate 20 is provided with a cutout 21 forming the blower inlet.
The center of the range of the cutout 21 is offset from the axis of the impeller 15. The direction of the shift is generally away from the outlet 12. The cutout 21 is shown generally in the shape of a sector of a circle which contains within itself the axis of rotation of the impeller. One edge 21 of the cutout 21
a forms a leading edge relative to the direction of rotation of the impeller. In this embodiment, the edge 21a is at an angle of 45 DEG to the axis of the outlet passage.
Generally, the angle between edge 21a and the axis of passageway 12 is selected within the range of 0 DEG to 135 DEG. Next, in the illustrated example, a bevel angle of 90° is formed between the downstream side 21b of the cutout 21 and the edge 21a. The groove angle is selected within the range of 45° to 240°. However, the larger the groove angle, the more the edge 21a
and the axis of the outlet passage 12 are selected to be small. The cutout 21 is then configured such that it is located approximately at a distance from the outlet 12 with respect to the blade axis.

A board member 22, generally in the shape of a vane, is secured to the board 20 around a portion of the cutout 21. The mountain board member 22
stands perpendicularly from the plate 20 such that it extends substantially parallel to the impeller 15 and close to the plate 17 inside the impeller 15 . A portion of the edge plate member 22 is the edge 21a of the cutout portion.
, thereby forming an angle of 45° to the axis of the outlet 12 in this embodiment. The jamb plate member 22 extends around the axis of rotation of the impeller 15 so as to be located generally between the inlet and the portion 11a of the spiral wall 11. The extent of the board member 22 is substantially the same for all sizes of the cutouts 21. The end of the jamb plate member 22 far from the plate 20 is partially surrounded by the boss 23 of the impeller plate 17.
Alternatively, the end of the cutting board member 22 may completely surround the boss 23 and be supported by the boss.

Operation In use, the blower operates to draw in air through the inlet cutout 21 and expel it through the outlet 12. A portion of the air within the gap 18 flows into the outer portion 19b of the gap space. That part of the air is moving in approximately the same direction as the direction of rotation of the impeller 15, and this swirling air can re-enter the impeller via the interstitial space 19a. If there is no cutting board like the one in this invention, when the speed of the air flow is low, the air will flow from the space 19b to the impeller 15.
enters the inside of the impeller and creates a counterflow through the impeller.
However, this counterflow causes turbulence and impairs efficiency. In this invention, the cutting board 22 extending along the cutout edge 21a has a radially outer end adjacent to the inner circumference of the impeller 15. The swirling air in the impeller 15 is then guided to the baffle plate 22 and directed through the vanes 16 near the smallest cross section of the gap 18 (ie near the junction point 11a). In addition, in the conventional type, the point where the impeller touches part 11a is the starting point of operation, so there was a risk that the high pressure air in the outlet passage would leak from part 11a to the spiral part. The point where the blade 22 touches the impeller 15 is the starting point of operation, and the junction point 11a
The air that passes through the impeller 16 at this point is the air that has already passed through the impeller and re-entered from the gap 18 through the spaces 19a and 19b.
has already been given energy, and when it comes out from the impeller 15 near the junction 11a, the pressure is high enough, so the There is also less leakage through the tube and less pressure loss.

As a variant, the cutout 21 can be provided with a flap or shutter which is pivotally attached to the plate 20 in order to be able to change its bevel angle. Such flaps or shutters can be used to change the pressure-volume characteristics of the blower and/or to adjust the total amount of airflow through the blower.

Effects As stated above, the blower of this invention has improved pressure-volume at low flow rates. FIG. 3 shows a characteristic curve 30 showing the relationship between the pressure DP caused by the blower and the flow volume V for the blower arrangement according to this invention. A characteristic curve 31 for a conventional blower of comparable size is shown for comparison, and it can be seen from this graph that significant improvements are made at low flow rates.

[Brief explanation of the drawing]

Fig. 1 is an end view of one embodiment of the radial blower of this invention, Fig. 2 is a sectional view taken along line 2-2 in Fig. 1, and Fig. 3 is a comparison diagram of the pressure-volume characteristics of the blower. ing. Explanation of symbols, 10... Casing, 11... Spiral peripheral wall, 11a... Joint portion, 12... Outlet passage, 13... Axial end wall, 14... Axial end,
15... Impeller, 16... Vane, 17... Board, 1
8... Gap, 19a, 19b... Space, 20...
Plate, 21... Entrance cutout, 21a, 21b...
Edge, 22...Jiyama board, 23...Boss, 30,3
1...Characteristic curve, DP...Pressure by blower, V
...Flow volume caused by a blower.

Claims (1)

[Claims for Utility Model Registration] It has an outlet passage 12 in the tangential direction and end walls 13 and 14, and the end wall 13 has a fan-shaped air intake cutout 2.
casing 1 on which a plate 20 having 1 is arranged;
0 and an impeller 15 rotatably disposed within the casing 10.
A gap 18 is formed between the outer periphery of the impeller 15 and the peripheral wall 11 of the casing, and the closest point between the outer periphery of the impeller 15 and the peripheral wall 11 of the casing is a junction point 11a between the outlet passage and a portion of the casing other than the outlet passage. , and the impeller 15 is aligned with the above-mentioned axial end wall 13.
In a radial flow blower for a burner, which is arranged so as to form gap spaces 19a and 19b between the end of the impeller and the end of the adjacent impeller, Board 22
However, it extends to the inside of the impeller 15 over the entire width of the impeller, and on the upstream edge 21a of the cutout 21, it extends to the point where it touches the impeller, and similarly on the downstream edge 21b, it extends to an appropriate length. The fan-shaped corner of the cutout is in the range of 45° to 240°, and the angle between the axis of the outlet passage 12 and the edge 21a is in the range of 0° to 240°.
A radial blower characterized in that the angle between the axis of the outlet passage 12 and the edge 21a is selected such that the angle between the axis of the outlet passage 12 and the edge 21a becomes smaller as the angle formed by the fan shape increases within the range of 135 degrees.