US3481530A

US3481530A - Diametral fan

Info

Publication number: US3481530A
Application number: US698555A
Authority: US
Inventors: Anatoly Grigorievich Korovkin
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-01-17
Filing date: 1968-01-17
Publication date: 1969-12-02
Anticipated expiration: 1986-12-02

Description

Dec. 2, 1969 A. cs. KOROVKIN 3,481,530

DIAMETRAL FAN Filed Jan. 17, 1968 3,481,530 DIAMETRAL FAN Anatoly Grigorievich Korovkin, Ulitsa Dovatora 11, korpus 2, kv. 38, Moscow, USSR. Filed Jan. 17, 1968, Ser. No. 698,555 Int. Cl. F04d 17/08, 29/52; F0111 1/30 US. Cl. 230125 3 Claims ABSTRACT OF THE DISCLOSURE A diametral fan having a rotatable impeller with curved vanes within which is mounted a guide apparatus including alternating long and short vanes respectively having outer edges in close proximity with the vanes of the impellet, whereas the inner edges of the outer vanes are also in close proximity with the vanes of the impeller, while the other vanes of the guide apparatus have inner edges remote from the vanes of the impeller. The end vanes of the guide apparatus define an entry at the inlet as measured along the arc of the impeller which substantially exceeds the outlet as measured from the outer edges along the arc of the impeller. The curvature of the vanes of the impeller and their spacing and the curvature of the vanes of the guide apparatus is such as to provide relatively high pressures at comparatively low circumferential velocities of the impeller.

The present invention relates to installations adapted to transfer gases, and more particularly, to diametral fans.

Diametral fans known heretofore comprise an impeller whose vanes are made concave in the direction of rotation of the impeller. The axis of rotation of the impeller isperpendicular to the direction of flow of the gas being transferred. The impeller accommodates an impeller guide vane assembly or guide apparatus which is capable of changing the direction of the gas flow emerging from that portion of the impeller which is in the vicinity of the delivery pipe of the fan (cf., e.g., FRG Patents Nos. 807,978 and 1,074,816).

The values of the maximum coefficient H of the total pressure (F=H/pu2) in these fans do not exceed H =2 to 2.2, the coefiicients of the fan capacity Q being equal to 1.4 or 1.5, where H is the total pressure of the fan in kg./sq. m., Q is the fan capacity in cu. m./sec., p is the density of gas in kg./sec. /m. b is the width of the impeller in m., D is the impeller diameter as measured at the vane tips in m., and w is the circumferential velocity of the impeller vane tips in m./sec. (cf., e.g., .FRG journal Heizung, Liiftung, Haustechnik, No. 12, 1957, p. 324). However, in case the diametral fans of said type are employed to transfer gas at a relatively high pressure, their overalldimensions and the circumferential velocity of the impeller should be considerably increased.

It is, therefore, the principal object of the present invention to provide a diametral fan which will feature relatively small overall dimensions and weight and be capable of ensuring relatively high pressures at comparatively low circumferential velocities of the impeller.

According to the present invention said object is attained due to the fact that the ratio between the deflection f of the center line of the profile of the curved impeller vane and the vane chord lies within 1:3.5 to 124.5, the angle of inclination p of the chord B relative to the impell r radius r drawn to the vane tip equals 1520 deg., the relation between the chord B and the vane spacing t equals 1.5-2.0, the vanes of the impeller guide vane assembly United States Patent ice or guide apparatus are arranged so that the angle '7 between the tangent AA to the exit edge of the guide vane and the straight line directed opposite to the vector of the circumferential velocity of the impeller does not exceed deg., and the ratio m/n between the lengths of the arcs m, n, at the inlet and exit edges of said vanes equals 1.5-1.6.

The test model of a diametral fan made in accordance with the present invention has the maximum pressure ratio I I equal to 3, and a capacity factor Q equalling 1.6.

Given hereinbelow is a detailed description of an exemplary embodiment of the present invention with due reference to the accompanying drawings, in which:

-FIG..1 is a longitudinal section through a diametral fan, according to the invention (longitudinal section);

FIG. 2 shows a portion of the impeller and of the impeller guide vane assembly or guide apparatus taken on an enlarged scale.

The diametral fan of the invention comprises" impeller 1 (FIG. 1) accommodated in housing 2. Suction and delivery pipes 3, 4 are arranged perpendicular to the axis of rotation of the impeller 1. Mounted in the central portion of the impeller 1 are fixed

curved vanes

5, 6, 7, 8 and 9 of an impeller guide vane assembly or guide apparatus, a cascade of curved vanes 10 of the impeller 1 rotating with respect to said fixed vanes. Gas is admitted to the impeller 1 via the suction pipe 3 and from vane channels of the impeller which pass near the pipe 3, said gas enters vane channels defined by the

vanes

5, 6, 7, 8 and 9. Said vanes being curved in shape, the direction of the gas flow is changed and the gas is fed at a preset angle to the vanes 10 of the impeller 1 which pass near by the delivery pipe 4.

The vanes 10 of the impeller .1 are made concave in the direction of rotation and are arranged along the circumference of the impeller. The relation between the deflection (FIG. 2) of the center line of the profile of each vane 10 and the chord B of said profile is within 1:35 to 1:45. The angle ,8 of inclination of the chord B relative to the radius r of the impeller 1 drawn to the tip of the vane 10 equals 15-20 deg. The relation between the chord B of the vane and the spacing t of the vanes 10 equals 1.5 to 2.0.

The vanes 5 and 8 of the impeller guide vane assembly or guide apparatus are arranged so, that their inlet edges adjoin the exit edges of the vanes 10 of the impeller 1, in the region of the outlet of suction pipe 3, with a small clearance, whereas the inlet edges of the vanes 7 and 8, are disposed at a relatively great distance from the exit edges of the vanes 10. The exit edges of vanes 5, 6, 7, 8 adjoin the inlet edges of vane 10 near the inlet of the suction pipe 4. It is obvious that when the impeller is rotating, the exit edges of the vanes 10 arranged near by the suction pipe 3 become the inlet edges as disposed near by the suction pipe 4.

The inlet edges of the vanes 5, 8 are arranged along an are In (FIG. 1), and the exit edges of the vanes 5, 6, 7 and 8 are arranged along the are n. The ratio m/n is 1.5 to 1.6. Located between the vanes 5, 6, 7 and 8 are the vanes of a smaller length, whose exit edges are disposed along the are n.

The angle '7 (FIG. 2) between the tangent AA at the exit edge of any of the

vanes

5, 6, 7, 8, 9 and the straight line directed opposite to the vector of the rotational velocity of the impeller 1 (a line tangent to the impeller periphery) does not exceed 90 deg.

What is claimed is:

1. A diametral fan comprising a rotatable impeller with curved vanes which are concave in the direction of rotation, each said curved vane having a deflection at the center which is in a ratio between 123.5 and 1:45 with respect to its chord, the chord being inclined and forming an angle of inclination relative to a radius of the impeller of a value between 15-20, said vanes being circumferentially spaced at a distance which is in the ratio between 1:1.5 and 122.0 relative to said chord; a fixed guide apparatus within said impeller for guiding the flow across the impeller and including alternating long and short vanes having respective inner and outer edges, said outer edges of the vanes being curved in the direction opposite to the direction of rotation of the impeller, each having a tangent at the outer edge thereof which forms an angle with the straight line directed opposite the vector of the circumferential velocity of the impeller which is less than 90, said vanes of the guide apparatus forming at their inner edges an arc measured along the impeller which is in a ratio with the are formed by the outer edges of the vanes of the guide apparatus as measured along the inner diameter of the impeller of between 1.5 and 1.6.

2. A fan as claimed in claim 1, wherein the outer edges of all of the vanes of the guide apparatus are in equal close proximity to the vanes of the impeller.

3. A fan as claimed in claim 2, wherein the end vanes of the guide apparatus are long vanes and have inner edges in close proximity to said vanes of the impeller, the remaining vanes of the guide apparatus having inner edges disposed within the impeller in substantial spaced relation from the vanes thereof.

References Cited UNITED STATES PATENTS 2,658,700 11/1953 Howe 230-125 2,942,773 6/1960 Eck. 3,23 8,725 3/1966 Ludin.

HENRY F. RADUAZO, Primary Examiner US. Cl. X.R. 230-133