How to solve the problem that the centrifugal fan has a small air volume and can reduce the density of the blades? The fan volume should be reduced 1. Reduce the fan speed, use the inverter or change the pulley ratio to reduce the speed; 2. The impeller diameter is smaller, and the small diameter is small; 3. Lower the width of the impeller outlet, reduce the flow to the area, and reduce the air volume; Is it a reduction? It depends on the specific situation and is judged. Concerned about surprises Label: How to solve the problem of small air volume of centrifugal fan? Previous: The hazard of airflow backflow in the impeller of the centrifugal fan? Next: What is the consequence of the sudden increase in the air volume of the fan?
Spade bits are used for rough boring in wood. They tend to cause splintering when they emerge from the workpiece. Woodworkers avoid splintering by finishing the hole from the opposite side of the work. Spade bits are flat, with a centering point and two cutters. The cutters are often equipped with spurs in an attempt to ensure a cleaner hole. With their small shank diameters relative to their boring diameters, spade bit shanks often have flats forged or ground into them to prevent slipping in drill chucks. Wood Spade Drill Bit,Fat Drill Bit,Paddle Drill Bit,Wood Drill Bit Behappy Crafts (suzhou)Co.,Ltd , https://www.jshaoyue.com
Some bits are equipped with long shanks and have a small hole drilled through the flat part, allowing them to be used much like a bell-hanger bit. Intended for high speed use, they are used with electric hand drills. Spade bits are also sometimes referred to as "paddle bits".
Spade drill bits are ordinarily available in diameters from 6 to 36 mm, or ¼ to 1½ inches.