US1998184A

US1998184A - Fan

Info

Publication number: US1998184A
Application number: US715786A
Authority: US
Inventors: Earle W Ballentine
Original assignee: SOLAR IND Inc
Current assignee: SOLAR IND Inc
Priority date: 1934-03-15
Filing date: 1934-03-15
Publication date: 1935-04-16
Anticipated expiration: 1952-04-16

Description

April 1935. w. BALLENTINE 1,998,184

FAN

Filed March 15, 1954 2 Sheets-Sheet l April 16, 1935.

E. w. BALLENTINE 1,998,184

FAN

Filed March 15, 1934 2 Sheets-Sheet 2 fizy/ 552 am- Zia.

- cold air inlet of a furnace (not shown).

Patented Apr. 16, 1935 UNITED STATES FAN Earle W. Ballentine, Chicago,

Solar Industries, Inc., tion of Illinois Ill., assignor to Chicago, 111., a corpora- Application March 15, 1934, Serial No. 715,786

4 Claims.

This invention relates to improvements in fans and, more especially, a pressure fan for furnace application.

Among the features of my invention is the provision of such a fan simple in construction and operation which can be manufactured and operated at relatively low cost. My improved fan is practically noiseless and has a high degree of efiiciency.

Another feature of my invention is the provision of a fan of the character described that can be used for furnace application and which will offer a minimum resistance to free gravity circulation when the fan is not operating. My improved fan is also substantially non-loading so that practically constant power is required at all deliveries. My improved fan is especially designed to operate vertically so that the air thrust counterbalances the weight of the fan and the shaft, so that a rotating system with minimum friction resistance is the result.

I have found that for a disc fan to efliciently produce pressure, it is necessary that the area of the blades approximate the face area of the fan. This consideration is limited only by the fact that it is necessary to have sufficient port area to give the necessary volumetric capacity. My improved fan has only two blades which, for example, may be approximately 22" in diameter and revolve at 750 R. P. M. This combination produces substantially no air waves of a frequency exceeding 25 beats per second and, therefore, the operation is substantially noiseless.

I also prefer to make the pitch of the blades uniform in order to give a uniform rate of displacement and, accordingly, a uniform pressure.

Other features and advantages of my invention will appear more fully as I proceed with my specification.

In that form of device embodying the features of my invention shown in the accompanying drawings- Figure l is a view in perspective; Fig. 2 is a diagrammatic view showing the shape of one of the blades; Fig. 3 is a top plan view of the fan; Fig. 4 is a view in side elevation; Fig. 5 is a diagrammatic view showing the dimensions and angle of inclination of the blades.

As shown in the drawings, the fan may be mounted in a suitable and rectangular casing ID to which is connected a boot ll leading to the Above the casing l 0 is a filter casing l2 designed to hold suitable filters l3 forming no part of the present invention. I4 indicates the cold air inlet. I5 indicates an orifice plate which is provided with a circular orifice l 6 which may, for example, be 24" in diameter.

I 1 indicates a spider supported on suitable legs I 8 carrying the bearing member IS in which is supported the shaft 20. This shaft may carry a belt wheel 2| on its lower end adapted to be driven by the belt 22 from the motor 23. The upper end of the shaft is provided with a fan hub 24 carrying the

inclined flanges

25, 25 to which the

blades

26, 26 are attached.

In the practice of my invention, the size, shape, proportions, dimensions and inclinations of the blades of the fan are important and, consequently, I shall describe these in detail, it being understood that both blades are similar. In Fig. 2 I have shown a circle 21, the diameter of which is the diameter of the fan. In this circle I have shown one of the fan blades 26 laid fiat. It will be seen that the width of this blade, as indicated by the line 26 is substantially uniform and is substantially of the diameter of the fan. In Fig. 5, I have shown diagrammatically a side view of one of the blades in order to indicate its inclination. In this view the diameter of the fan is indicated by the line 26'. As stated above, the width of the blade is 75% of the diameter. When the blade is inclined as shown in Fig. 5 at an angle of 28 to the horizontal, its projection on the diameter will extend from the point A to the point B and this distance is substantially 65% of the diameter. I have found that very good results are obtained when the blades are made and inclined as shown in Figs. 2, 3 and 4, that is, when the blade has such inclination and width that its projection is substantially 65% of the fan diameter. In other words, I have found that with less inclination the blade ought to be made narrower, and vice versa, in order to keep the projection between 40% and of the fan diameter. As shown, such projection is 65% of the fan diameter and, as stated, .I have found this to give good results. As stated above also, the width of the blade as shown is 75% of the fan diameter. I have found this to give good results, although such width may vary from 50% to of the fan diameter. Also, as stated, I have found the inclination of 28 to give good results, although it appears that such angle may vary from 15 to 45.

It will be noticed also that I prefer to curve the ends of the blades. This is shown in Fig. 2 where the curvature of the end is indicated by 30, such curvature being the arc of a circle.- Such the spirit and scope of Y prior art.

curved ends'give the maximum blade area in a given diameter. r 7 while 1 have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from my invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in 1117 invention as broadly as permissible, in view of the whatlclaimasnemanddesiretosecureby Letters Patent, is:

1. In combination with a casing, 'a rotary air fan therein adapted to move air in said casing against static pressure therein, said ian including a hub and only two similar blades, said blades oppositely arranged and inclined with respect to said hub and attached thereto, each blade having a radial length substantially equal to halt the ian therein adapted -to. .move air in said casing.

against static pressure therein,"said ian including a hub and only two similar blades, said blades oppositely arranged and inclined with respect to said hub and attached thereto, each blade having a radial length substantially equal to halt the distance between the tips of the blades and a substantially uniform width throughout its length 3. A device as claimed in claim 1, in which the inclination of the blades with respect to the plane of rotation is less than 4. A device as claimed in claim 2, in which the inclination of the blades with respect to the plane oi rotation is less than 45".

EARLE w. BALLENTINE.

of substantially of its radial length.