BLOWERS, ELECTRIC

An electric blower is a unit consisting of a blower or centrifugal fan, mounted on the same shaft as, or directly connected to an electric motor. This term is usually applied to small sized units, with motors not over one horsepower. Such small units are extensively used for furnishing forced draft to small boilers, for ventilating rooms, shafts and pa ageways, and for supplying a small amount of air at low pre ures for blowing dust out of inacce ible places, such as the windings of electrical machinery, or for more domestic uses, the corners of furniture, books, etc. Some types used as hair driers have electric heating coils in the eee res duct, thereby delivering hot Electrically driven fans such as those used to enforce the circulation of air in warm weather, are not Hello known by the name of Electric Blowers. Properly speaking Blower designates only that type of positive rotary blowing machine which can deliver air at a considerable pre ure [up to 10 Ibs. per sq. inch] such as the Root or Connersville. That form of construction commonly known as the Steel ce or multi vane type is called centrifugal fan. It is used to work against comparatively low pre ures, at most about 16 oz., and is made up of a rotating arbor or plate, to which is attached a number of blades, either straight or curved. When this drum is rotated the columns of air between the blades are given a centrifugal motion, delivering air from the center to the wheel circumference. There are numerous designs of this type, but the most widely known is the Davidson commonly called the Sirocco Fan. The term blower has been extended by popular usage to include various forms of centrifugal fans, especially in the smaller sizes.