Patent ID: 9046108
Filing Date: 2015-06-02
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 number of 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 impeller blades are each spaced asymmetrically about a central hub such that a summation of the nominal blade angles 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 10.7792°, the second nominal blade angle value is 11.5672°; the third nominal blade angle value is 12.7214°; the fourth nominal blade angle 12.6427°; the fifth nominal blade angle value is 11.7955°; the sixth nominal blade angle value is 10.7489°; the seventh nominal blade angle value is 10.2102°; the eighth nominal blade angle value is 10.5044°; the ninth nominal blade angle value is 11.4303°; the tenth nominal blade angle value is 11.2102°; the eleventh nominal blade angle value is 11.6129°; the twelfth nominal blade angle value is 13.0226°; the thirteenth nominal blade angle value is 11.2263°; the fourteenth nominal blade angle value is 10.8982°; the fifteenth nominal blade angle value is 9.9924°; the sixteenth nominal blade angle value is 12.0156°; the seventeenth nominal blade angle value is 13.4934°; the eighteenth nominal blade angle value is 13.0156°; the nineteenth nominal blade angle value is 12.3276°; the twentieth nominal blade angle value is 12.4769°; the twenty-first nominal blade angle value is 11.9995°; the twenty-second nominal blade angle value is 11.6586°; the twenty-third nominal blade angle value is 10.5831°; the twenty-fourth nominal blade angle value is 9.7324°; the twenty-fifth nominal blade angle value is 9.8737°; the twenty-sixth nominal blade angle value is 10.1688°; the twenty-seventh nominal blade angle value is 12.4466°; the twenty-eighth nominal blade angle value is 10.2032°; the twenty-ninth nominal blade angle value is 13.0570°; the thirtieth nominal blade angle value is 13.3521°; and the thirty-first nominal blade angle value is 13.2334°.