US2125120A - Directing vane - Google Patents

Description

July 26, 1938. K. D. MCMAHAN DIRECTING VANE Fil May 25. 1936 2 Sheets-Sheet l Fig. 2.

Invent Kenton UM M bld W iw,

, H Attorney;

July 26, 1938. K. D. MCMAHAN DIRECTING VANE Filed May 23, 1956 2 Sheets-Sheet 2 Patented July 26, 193

nmEo'nNG VANE Kenton D. McMahan, Schenectady, N. Y;,assignor to General Electric Company, a corporation of New York Application May 23, rise, Serial No. 81,433

Claims. (o1. 231 274) drawings, in which Fig. 1 is a perspective view of a casing with my improved directing vanes around an opening from which a fan is mounted to propel air therefrom; Fig. 2 is a similar perspective view of a portion. of the casing with the directing vanes located in a different position; Fig. 3 is a front view of a fan with directing vanes; Fig. 4 is a sectional view along line 4-4 of Fig. 3; Fig. 5 is a sectional view along line 5-5 of Fig. 3; Fig. 6 is a front view of a single vane;

Fig. 7 is a sectional view along line 'l- -'l of Fig.

6; Fig. 8 is a sectional view along line 88 of Fig. 6; Fig. 9 is a sectional view along line 9-9 of Fig. 6; Fig. 10 is a sectional view along line liil0 of Fig. 6. and Fig. 11 is a sectional view along line H--ll of Fig. 6.

Referring to the drawings, 20 indicates a casing in which may be located apparatus for cooling or heating the air passing through the easing. To remove the air from the casing 20 after it has been cooled or heated, a fan 2| is mounted in an opening 22 in the casing and adapted to propel air from the opening. Fan 2| is arranged to rotate in a clockwise direction. A fan of the propeller type either mounted in an opening such as opening 22 or mounted for operation in free air, propels the air in a diverging column, the diverging column entraining air as it moves from the fan end so in this manner greatly increasing the cross sectional area of moving air at a greater distance from the fan. In addition, this diverging column of air propelled by the fan has a rotational component. In other words, this column of air may be described as a whirling column of increasing diameter from the fan. The rotation of the air column does not accomplish a desirable result and consumes energy which might be utilized in propelling the air. In addition, a diverging column is frequently objectionable as for example in an air conditioning unit the diverging column may impinge directly against a person who is located in the proximity 55 of the air conditioning unit which is highly ob- Jectionable because of the relatively high temperature or /relatively low temperature, as the case may be; of the air leaving the unit. This is true even though the average temperature in the vicinity of the unit is not in itself objectionable. The problem in this case is to mix the air leaving the unit thoroughly with the air in the surrounding space without any of the air from the unit coming directly in contact with anyone before it is mixed with the surrounding air. It has been found in the case of cooling units that they may most advantageously be located near the ceiling of a room in order to utilize the natural circulation of cold air from the top to the bottom of the room. However, the air leaving the cooling unit is at such a relatively low temperature and high specific gravity that it has a tendency to spill over, as it is termed, immediately after it leaves the cooling unit. To overcome this tendency it is necessary to propel the air at a relatively high velocity from the cooling unit. However, if afan is used which will produce a high velocity and will throw the air a great distance from the cooling unitbefore it begins to fall, an excessive amount of power must be used .in the fan. The column of air diverges through such a large angle that it may cause some of the air to directly impinge upon persons within the room. In some instances the cooling unit may be mounted on the side wall of a room which is long in comparison with its width and so it is desirable to direct the air from the cooling unit in a band with a wide angle of divergence in that band to distribute the air throughout the length of the room. To overcome these difficulties and to assist in projecting the air in a narrow band at a relatively great distance or with a wide angle of divergence from the cooling unit with the use of an ordinary size fan, directing vanes 23 and 24 are provided. Directing vanes 23 and 24 are located in front of the fan around the ,exhaust side of opening 22. Directing vanes 23 and 24 are mounted on a ring 25 and are located at diametrically opposite sides of theopening 22. Aguard 26 for the fan 2l is also mounted on the ring 25. Directing vanes 23 and 24 occupy substantially one quarter of the circumferential. extent of the ring 25. In other words, the directing vanes 23 and 24 subtend substantially a angle.

The action of the vanes on the air may be understood by reference to Figs. 3, 4 and 5. In Fig. 3 a front view is shown'in which vanes 21 and 28 are mounted in position for directing the air in the horizontal band from an orifice 29 in 1. Fan 38 rotates in a clockwise direction.

which a fan 38 is located. Vanes 21 and 28 are in the same position as vanes 28 and 24 in Fig. The air moving through orifice 29 tends to diverge, at the same time rotatingin a clockwise direction. The highest velocity in the stream of air as it passes through the orifice 29 is near the outer periphery of the fan 30. This high velocity air comes in contact with either vane 21 or 28 passing around the vane in a clockwise direction and discharging from the edge of the vane in a horizontal plane. The effect on the air by the vane may be understood by referring to Figs. 6 to 11. In Fig. 6 an end view of vane 21 is shown. Figs. 7 to 11 are sectional views of vane 21 cut by radial planes along the lines 1 to II respectively. It will be seen from Figs. '1 to 11 that the vane 21 curves inwardly toward the axis of rotation of the fan and outwardly from the face of the fan. The vane 21 decreases in width in a clockwise direction and the curvature also decreases in radius, or, in other wordspincreases in rate of curvature in a clockwise direction. Thus, as the high velocity air travels in contact with the vanes 21 and 28 rotating in a clockwise direction it is acted upon and-directed with an increasing force as it passes in a clockwise direction and is discharged from the edge of the vanes tangentially to the surface of the vanes in a horizontal plane. Much of the air'passing through the orifice 29 does not actually come in contact with either vane 21 or 28 but the streams of air discharged from the vanes 21 and 28 serve to deflect and thus direct the remaining air. In Fig. 3, the arrows show the direction of the air to be in a horizontal plane, the air directed by vane 21 passing to the right and the air directed by vane 28 passing to the left. In Fig. 4 it may be seen that the air does not diverge in a vertical direction at all as it leaves the vanes 21 and 28. In Fig. the arrows indicate the direction of air movement in the horizontal plane to be divergent in a horizontal direction. The rotational component of the air passing through the orifice 29 causes the air to remain in contact with the vanes 21 and 28. Thus, the rotational component of the air is utilized to produce a force to direct the air in a horizontal plane and as a result overcomes or .eliminates the rotational component. This rotational component, as mentioned above, does not have any advantage, but if not eliminated tends to reduce the energy which may be utilized in moving the air forward by consuming it in the rotational movement, the vanes 21 and 28 thereby utilizing the component of force which is detrimental and thus eliminating this force improves the operating condition of the fan or device producing the air movement. In addition, vanes 21 and 28 extend over but a very small portion of the disc area of the fan 30 or over the opening of the orifice 29. The directing vanes 21 and 28 utilize an undesirable force to direct the air and do not extend in the path of air flow so as to interfere with the free movement of the air. The distance the air is propelled is actually increased by the use of the directing vanes 21 and 28 and no back pressure is created which would reduce the flow of air as normally encountered with the conventional types of directing vanes or bailies. Also, the directing vanes 21 and 28 do not increase the noise of operation of the fan by more than an imperceptible amount. In many cases the vanes which are located directly in the path of air flow may increase the noise energy of air movement two or three times that of the air movement without the directing vanes. If it is desired to make the angle of divergence greater in a horizontal plane with the vanes placed as in Fig. 1, it is only necessary to decrease the radius of curvature successively in a clockwise direction throughout the length of the vane. Similarly, if a lesser angle of divergence is desired the radius of curvature throughout the length of the vane could be increased. For a fan operating in a counterclockwise direction, it is obvious that the vane would have to be reversed in direction and the decrease in the radius of curvature would be in a counterclockwise direction. With these directing vanes 21 and 28, it is possible to produce a .flat plane or band of air from any openingthrough which air is passing and the band may be directed in any plane desired, and within reasonable limits any angle-of divergence may be obtained. If it is desired to merely remove the rotational component of the air stream or to obtain a wide divergence of the air stream in all directions more than two vanes may be used.

By moving the vanes 28 and 24 of Fig. 1 through an angle of substantially 90 and locating them in the position shown in Figs. 2, the air passing through the opening 22 may be converted into a vertical band of air in which the air movement from the fan diverges only in a vertical direction. By positioning the directing vanes 28 and 24 at an intermediate position between the positions shown in Figs. 1 and 2, a band of air may be directed at any angle to the vertical or horizontal desired.

From the foregoing, it may be seen that by the provision of my directing vanes the rotational component of air movement of [a diverging column of air may be utilized to ponvert it into a narrow band of airwhich may be moved a great distance without increasing the amount of power necessary to move the air and without increasing the noise level of operation or may be used to produce a diverging column of air without a rotational component.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Directing vanes for a moving column of air having a rotational component about the axis of flow passing through an opening comprising two members circumferentially spaced apart around and extending axially from the opening in the direction of flow and having a decreasing radius of curvature in the direction of the rotational component of air moving through the opening whereby to produce a band of air without rotational component.

2. Means for directing the air moved by a propeller type of fan in a band including two circumferentially spaced apart axially extending vanes curved with a decreasing radius of curve.- ture in the direction of rotation of the fan to convert the rotational component of air into a diverging stream.

3. In combination, a fan, and means for directing the air propelled by the fan in a band including two circumferentially spaced apart axially extending vanes each having a decreasing radius of curvature in the direction of rotation of the fan and mounted in front of the fan in line with the outer periphery of the fan blades.

4. In combination, means to propel a column of air through a circular opening, said column of air rotating about the axis of flow, and axially extending vanes mounted around the opening each occupyin substantially a quadrant of the opening and curved inwardly toward the center or the opening with a decreasing radius of curvature in the direction of rotation of the air to direct the air from the opening in a band.

5. In combination, an orifice, means to propel air through the orifice, said air rotating about the axis of the orifice, circumi'erentially spaced apart axially extending vanes mounted on the exhaust side of the orifice around the periphery of the orifice, said vanes being curved inwardly with a decreasing radius of curvature in the direction of rotation of the air from one end of the vane to the other whereby the air passing out from the orifice is discharged between the vanes in a common plane diverging only in that plane.

6. In combination, a fan, and means to convert the air propelled by the fan into a band, including two vanes substantially in extent mounted in front of the fan in line with the peripheral edge of the fan, said vanes being curved inwardly toward the axis oi. rotation of the fan and outwardly from the fan with a decreasing radius of curvature and decreasing width in the direction of rotation of the fan.

7. In combination, a fan, and means for directing the air propelled by the fan in a diverging column without rotational component including a plurality of axially extending vanes each having a decreasing radius 01' curvature in the direction ofrotation of the fan, and mounted in front of the fan in line with and spacedapart around the outer periphery of the fan blades.

8. Directing vanes for an axially moving colvature.

umn of air having a rotational component about the axis of flow, comprising a plurality of axially extending vanes spaced apart around and extending circumferentially in contact with the periphery of the air column and restricting the normal divergence of the air column whereby the rotational component of the air is converted into an axial component.

9. Directing vanes for an axially moving column of air having a rotational component about the axis 01' fiow, comprising a plurality of axially extending vanes spaced apart around and in contact with the periphery of the air column and restricting the normal divergence oi. the air column whereby the rotational component of the air is converted into an axialcomponent, said vanes having a decreasing radius of curvature in the direction of rotation of the air.

10. Directing vanes for an axially moving column of air having a rotational component about the axis of flow, comprising a plurality of axially extending vanes spaced apart around and in contact with the periphery of the air column and restricting the normal divergence of the air column whereby the rotational component of the air is converted into an axial component, said vanes being curved inwardly toward the axis of rotation of the air and outwardly in the direction of fiow of the air with a decreasing radius of cur- KENTONFD. MCMAHAN.

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