Patent ID: 9039393
Filing Date: 2015-05-26
Classification: F04D

Abstract:
1. A centrifugal blower, comprising: a motor having a number of pole passes, wherein the number of pole passes is an even number; and thirty one impeller blades, wherein each of the thirty one impeller blades is associated with a nominal blade angle, the nominal blade angle being an angular displacement between adjacent impeller blades, wherein the thirty one blades are each spaced asymmetrically about a central hub such that a summation of the nominal blade angle values is equal to 360° and an operating characteristic value of the centrifugal blower is deemed to be within a pre-determined range of operating characteristic values, wherein the first nominal blade angle value is 10.1034°, the second nominal blade angle value is 10.0229°; the third nominal blade angle value is 13.1577°; the fourth nominal blade angle value is 13.2029°; the fifth nominal blade angle value is 13.6692°; the sixth nominal blade angle value is 13.0442°; the seventh nominal blade angle value is 13.5653°; the eighth nominal blade angle value is 11.9834°; the ninth nominal blade angle value is 11.6129°; the tenth nominal blade angle value is 10.1071°; the eleventh nominal blade angle value is 11.2424°; the twelfth nominal blade angle value is 10.1532°; the thirteenth nominal blade angle value is 10.1816°; the fourteenth nominal blade angle value is 9.7922°; the fifteenth nominal blade angle value is 13.4336°; the sixteenth nominal blade angle value is 13.6681°; the seventeenth nominal blade angle value is 12.6063°; the eighteenth nominal blade angle value is 9.5578°; the nineteenth nominal blade angle value is 10.0681°; the twentieth nominal blade angle value is 10.7533°; the twenty-first nominal blade angle value is 11.1850°; the twenty-second nominal blade angle value is 13.5670°; the twenty-third nominal blade angle value is 12.4725°; the twenty-fourth nominal blade angle value is 13.1224°; the twenty-fifth nominal blade angle value is 13.0726°; the twenty-sixth nominal blade angle value is 13.1187°; the twenty-seventh nominal blade angle value is 12.0408°; the twenty-eighth nominal blade angle value is 10.6195°; the twenty-ninth nominal blade angle value is 9.5566°; the thirtieth nominal blade angle value is 9.6588°; and the thirty-first nominal blade angle value is 9.6605°.