Improvements in Blowers.
Year: 1894

page_text: CUMI DIE DI PULTIVATION
Improvements in Blowers.
I, GEORGE ASHBELL SPANG, of North Tonawanda, in the State of New York,
United States of America, Gentleman do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :—
My invention relates to improvements in blowers of the classes known respectively
as pressure, exhaust, and volume blowers, and the object in view is to so arrange
the co-operating fans that they will discharge into a common outlet, whereby, with
the same peripheral velocity and number of revolutions per minute of the fans, the
pressure and velocity of the blast will be increased, or conversely, whereby the
same pressure and velocity of blast may be attained with a reduced peripheral
velocity and a less number of revolutions per minute of the fans.
With this object in view, I arrange the fans tandem and employ a common
outlet which is arranged at a common tangent thereto, each fan being provided
with an inlet and the blast from all of the fans proceeding in a common direction
and combining to form a common blast.
Further objects and advantages of this invention will appear in the following
description and the novel features thereof will be particularly pointed out in the
appended claims.
In order to show the application of my invention it is necessary to illustrate the
same in connection with only one of the above forms of blowers, and therefore, in
the drawing!
Fig. 1 is a perspective view of a pressure blower embodying my invention.
Fig. 2 is a longitudinal section of the same.
Fig. 3 is a plan view.
Similar numerals of reference indicate corresponding parts in all the figures of
the drawing.
1 and 2 represent respectively, the front and rear fan casings, provided with side
inlets 3, and 4 and 5 represents the common discharge or outlet, which is straight
throughout its length and is arranged at a tangent to the two casings, suitable
supports 6 being provided upon the lower side of said discharge. Projecting
laterally from the opposite sides of the casings are brackets 7 carrying the journal
boxes 8, in which are mounted the fan-shafts 9 and 10, which extend respectively
through the casings 1 and 2. Said shafts carry the rotary fans 11 and 12 which
are adapted to rotate in the same direction, as indicated by the arrows in Fig. 2
and motion is communicated to the fans through the belt-pulleys 13 and 14 which
are secured respectively to the shafts 9 and 10 upon opposite sides of the vertical
plane of the fan-casings.
Reference to Fig. 2 will show that the movements of the lower sides of the fans
are directly in alignment with the discharge 5; and, as the fan-casings are
separated by the intervening wall 15, which extends downward below the plane of
the top of the outlet-end of the discharge, the discharge from one of the fans
cannot produce back pressure upon the other. The shaft of the frout fan is
arranged in the plane above that occupied by the shaft of the rear fan, thereby
causing the rear fan to discharge in a plane somewhat lower, or beneath that of
the front fan, the two blasts being united and proceeding in a common direction
after leaving the front fan. It will be noted that the curvature of the rear wall of
the front fan-casing prevents the air which is discharged from the front fan from
meeting the current of air which proceeds from the rear at an abrupt angle, and
producing conflict and interference with a consequent loss of velocity, but on the

page_text: other hand the two currents of air leave the fans by which they are produced in
approximately parallel planes or directions and thence proceed in a common
direction without diminishing the combined effect.
In the drawing, I have shown the front fan of a somewhat smaller diameter
than the rear fan and in practice it is desirable to drive the front fan at a greater
velocity than the rear fan.
I am aware that it is common to construct blowers with twin fans connected with
a common discharge by means of a Y-pipe, but the disposition of the arms of this
Y-connection causes the two blasts to unite at an angle, thereby producing an
interference and friction which is avoided by the tangential arrangement above
described.
It will be understood that the essential features of the above described
improvement are applicable to blowers of different kinds and employed for different
purposes, and that in adapting the same to these various forms of blowers, various
changes in the form, proportion and the minor details of construction may be
resorted to without departing from the principle or sacrificing any of the
advantages of this invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. A blower having a plurality of fans, disposed in tandem, and a common
discharge or outlet arranged tangentially to said fans, substantially as specified.
2. A blower having a plurality of fans and a common discharge or outlet
arranged tangentially to and upon the same side of said fans, substantially as
specified.
3. A blower having a plurality of fans disposed in tandem and arranged in
independent fan-casings provided respectively with air-inlets, and a
discharge or outlet arranged tangentially to the fans, substantially as specified.
common
4. A blower having a plurality of fans, and a common discharge or outlet
arranged at a tangent to said fans, the shaft of the rear fan being arranged in a
plane below that of the shaft of the front fan, whereby the rear fan discharges in a
plane lower than the front fan, substantially as specified.
5. A blower having a plurality of fan-casings and a common discharge or outlet
connecting said casings and arranged at a tangent thereto, a separating wall
arranged between the fan-casings and extending below the plane of the upper side
of said discharge or outlet, and rotary fans located respectively in the said casings,
each casing being provided with an air inlet, substantially as specified.
Dated this 18th day of May 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.