摘要 |
This invention relates to a fan suction chamber having front, back, and bottom walls. The front wall defines a suction inlet; and the back wall has an upper section, which is parallel to the front wall, and a lower section, which slants downward and forward toward the front wall of the suction chamber at an angle of 67 DEG to 78 DEG with the horizontal. The bottom wall of the suction chamber connects the front wall and the lower section of the back wall. The depth of the chamber at the upper section of the back wall is 0.35 to 0.38 times the width of the suction chamber, and the depth of the chamber at a lower end of the lower section of the back wall is 0.14 to 0.18 times the width of the suction chamber. The diameter of the suction inlet is 0.42 to 0.50 times the width of the suction chamber. |