US2471178A - Air cleaning axial flow blower - Google Patents

Description

May 24, 1949. R. WALSH AIR CLEANING AXIAL FLOW BLOWER Filed Sept. 3, 1947 h ws w ma m V? b mm Z Patented May 24, 1949 UNITED SS TENT OFFICE Robert Walsh, Wilmington, Del., assignor to General Electric Company, a corporation of New York Application September 8, 1947, Serial No. 771,955

5 Claims. 1

My invention relates to improvements in axial flow blowers, and more particularly to blowers of this type incorporating improved means for the removal of dirt and foreign particles from the air.

In many fields the need for an adequate supply of clean air, free from dirt or other foreign particles, is of paramount importance to the effective operation of certain apparatus. This is particularly true in the railway field with special emphasis on the supply of ventilating air to the electric driving motors for supplying tractive efiort to railway locomotives. Due to their inherently small physical size and relatively large electrical rating, such motors require a large volume of cooling air in order to prevent overheating during continued periods of operation. Also, due to their physical location, being mounted either on or near the driving truck, they are in a position where large quantities of dirt and dust, agitated from the roadbed, may enter through the air circulating means.

It is, therefore, especially important that the motors designed for mounting on railway equipment and also on other equipment, which must operate under conditions where a large amount of foreign matter or dirt is present in the air, be provided with suitable air circulating means, such as fans, or blowers, in which provision is made for eficient removal of all, or substantially all,

of the dirt and foreign matter from the cooling air before it is supplied to the electrical machinery.

It is, therefore, an object of my invention to provide an improved air cleaning type of axial flow blower.

It is another object of my invention to provide an improved form of axial flow fan that is simple, compact and effective in removing dirt and foreign particles from the air stream.

In accordance with a preferred form of my invention, I provide an axial-flow type of electric motor driven blower which is compactl built and designed for mounting in restricted space such as beneath the underframe of a locomotive. The air enters the blower radially and is deflected around a ninety degree bend, thereby separating the entrapped foreign material from the main body of the air stream by centrifugal action. The fan construction of the blower is provided with dual concentric sets of blades which are in axial alignment with the divided air stream, the inner set of blades acting as scavenging blades and providing only enough suction to insure that the dirt-laden air is propelled through the casing to a discharge. The outer set of concentric blades are in axial alignment with the main air stream, and supply the required pressure to force the clean air to the railway traction motors, or to any other use in which a pressurized supply of clean air is required.

For a better understanding of my invention, reference should now be had to the accompanying drawing in which Fig. 1 shows schematically in cross section a view of my improved air cleaning axial flow blower; Fig. 2 is a radial cross sectional view taken along the line 2-2 of Fig. 1 showing the pitch of the inner scavenging blades, and Fig. 3 is also a radial sectional view, taken along the line 33 of Fig. 1, showing the pitch of typical outer axial flow fan blades.

Referring to the drawing, I have shown the horizontal plate or supporting member I upon which the device is mounted and which may be the underside of a locomotive cab or main frame. Secured to the plate i is a vertically mounted electric motor 2 carrying on the lower end of its rotor shaft the spider 3 which supports two sets of fan blades. The fan spider 3 is provided with an inner rim 4, an intermediate rim 5, and an outer peripheral rim 6. Surrounding the motor drive unit 2 is a cylindrical enclosure l for preventing dirt and foreign material from entering the enclosed motor space. The total unit including the motor 2, spider 3 and air cleaning apparatus is surrounded by an enclosure 8 which, as shown in Fig. l, is provided with an annular opening 9 around the upper portion through which the dirt laden air enters. The clean air is discharged under pressure at the lower end of the casing Ill from whence it may be supplied to the encased electric drive motors of the locomotive, or any other apparatus requiring cleaned air. Positioned concentrically with the inner casing l and entirely surrounding this casing is the intermediate casing H which defines an annular space and, as shown, is also open at the upper end l2 forming an inlet for the dirt laden air. The lower end of the annular space between the casings 'l and l I is connected to the discharge pipe 13 which opens to the atmosphere and through which the dirt laden air is removed from the apparatus for disposal in any convenient manner.

From the drawing, Fig. 1, it will be noted that the inner rim 4 of the motor spider is axially aligned with the inner casing l and the intermediate rim 5 is axially aligned with the intermediate casing II, thereby defining a continuous annular chamber surrounding the motor space exhausting to the outlet I 3. The outer rim 6 of casing, and an outer set of radial blades having their inlet side in alignment with the space between said intermediate casing and said outer casing, and duct means adjacent the discharge side of said inner and outer sets of blades for maintaining separate the gas flow through said inner and outer sets of impeller blades.

5. An axial flow gas cleaner and blower comprising an outer cylindrical casing having a peripheral gas inlet adjacent one end thereof, an inner casing concentric with said outer casing, an intermediate casing between said inner and outer casings and concentric therewith, a driving motor within said inner casing and axially aligned therewith, a rotary gas impeller secured for operation to said driving motor, said impeller consisting of an inner set of radial blades having their inlet side in alignment with the space between said inner casing and said intermediate blade pitch than said outer set of blades, and

partitioning duct means adjacent the discharge side of said inner and outer sets of blades for maintaining separate the gas flow through said inner and outer sets of impeller blades.

ROBERT WALSH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,720,863 Stebbins July 16, 1929 2,375,203 Appledoorn May 8, 1945

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