AXIAL FLOW FAN ASSEMBLY

• US 3,768,546 A
• Filed: 12/27/1971
• Issued: 10/30/1973
• Est. Priority Date: 12/27/1971
• Status: Expired due to Term

• Current Assignee: Kelly V. Shipes
• Original Assignee: Kelly V. Shipes
• Inventors: Shipes, Kelly V.
• Primary Examiner(s): Raduazo, Henry F.
• Application Number:
  US05/212,555
• Time in Patent Office: 673 Days
• Field of Search: 415/198,199,130,127,149 261/DIG.10 416/130 165/39,96,122 138/39
• US Class Current: 165/96
• CPC Class Codes: F04D 19/007 multistage fans
• CPC Class Codes: F04D 19/024 with contrarotating parts
• CPC Class Codes: F04D 27/002 by varying geometry within the pumps, e.g. by adjusting vanes
• CPC Class Codes: F04D 29/362 during rotation
• CPC Class Codes: F28B 1/06 using air or other gas as the cooling medium
• CPC Class Codes: F28F 2250/08 Fluid driving means, e.g. pumps, fans
• CPC Class Codes: Y10S 165/90 Cooling towers

Abstract

An axial flow fan assembly having two or more fans in series to provide successive fan stages in which less than the total number of fans are of the variable pitch type.

Claims

1. An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first and second axial flow fans mounted coaxially within the fan ring and relatively close together, means for rotating the first and second fans, the blades of the first fan having a positive pitch which is non-adjustable during rotation thereof and arranged to move the air through the fan ring in a direction from said first fan to said second fan, and remotely operable means for adjusting the pitch of the blades of the second fan, during rotation thereof, within a range between positive pitches gerater than and less than the positive pitch of the blades of the first fan.

2. An air cooler of the character defined in claim 1, wherein said remotely operable pitch adjusting means includes means for adjusting the blades of the second fan to a negative pitch.

3. An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first, second and third axial flow fans mounted coaxially within the fan ring, the first fan being relatively close to the second fan, and the second fan being relatively close to the third fan, means for rotating the first, second and third fans, the blades of the first fan having a positive pitch which is non-adjustable during rotation thereof and arranged to move the air through the fan ring in a direction from said first fan to said second fan, and remotely operable means for adjusting the pitch of the blades of each of the second and third fans, during rotation thereof, within a range between positive pitches greater than and less than the positive pitch of the blades of the first fan.

4. An air cooler of the character defined in claim 3, wherein said remotely operable pitch adjusting means includes means for adjusting the blades of the second and third fan to a negative pitch.

5. An air cooler, comprising a tube bundle, and an axial flow fan assembly mounted on one side of the tube bundle for causing air to pass thereacross, said fan assembly including a fan ring, first, second and third axial flow fans mounted coaxially within the fan ring, the third fan being relatively close to the second fan, and the second fan being relatively close to the third fan, means for rotating the first, second and third fans, the blades of each of the first and second fans having a postivie pitch which is non-adjustable during rotation thereof and arranged to move air through the fan ring in a direction from the first fan to the second fan and from the second fan to the third, with the pitch of the blades of the second fan being greater than the pitch of the blades of the third fan, and remotely operable means for adjusting the pitch of the blades of the third fan, during rotation thereof, within a range between the positive pitches greater than and less than the positive pitch of the second fan.

6. An air cooler of the character defined in claim 5, wherein said remotely operable pitch adjusting means includes means for adjusting the blade of the third fan to a negative pitch.