Improvements in High Gauge Centrifugal Fans, and Fittings for the same, Applicable also to Centrifugal Pumps.
Year: 1896

page_text: Improvements in High Gauge Centrifugal Fans, and Fittings for the
same, Applicable also to Centrifugal Pumps.
I, GEORGE MARIE CAPELL of Passenham near Stony Stratford Clerk in Holy
Orders do hereby declare the nature of this invention to be as follows:-
It is an established fact that curved outer blades of a fan revolving with the
concave portion in direction of rotation, produces the highest water gauge effects,
while the mechanical, or useful effect, is low, and that a curved fan blade moving
with its convex surface in the direction of rotation gives lower water guage, but
a higher mechanical or useful effect.
In my invention I use a compound outer blade to my fan, consisting of two
parts. One is a curve struck from a centre outside the periphery of the fan and
lies between the periphery and the inlet circle, forming a concave blade in the
direction of rotation. I then form another curved blade, meeting the first blade,
and secured to it across the width of the fan, at a point about midway between
the inlet circle and the periphery of the fan, to which this second wing, with
its convex surface in direction of rotation extends. I do not confine myself to
a curved blade for this second wing, as in some cases it can be straight.
The space between the forward blade and the rear blade at the periphery,
may be closed to prevent Eddies, but it is not indispensable.
This compound outer wing or blade may be used in conjunction with straight
or curved inner blades or wings.
The fans may have any suitable number of these compound outer wings or
blades and be constructed with or without side discs, and with the usual boss
or bosses and axle. They may also be used with or without casings, and with
Evasé outlets in the case of mine fans for large volumes of air. In high guage
mine fans, great difficulty exists in entering the fan drifts to oil the bearings,
the great velocity of the air flow at the fans inlet rendering approach to the
bearings dangerous. I make a bearing frame of a hollow conical form, resting on
the masonry of the air passage and projecting into it, towards the fan inlet.
In this holow cone, I place my bearing, or bearings in double inlet fans, which
are thus accessible from the outside of the air passage and also they enable a
shorter shaft to be used for the fan, which reduces vibration at high speed.
The improvements described for fan wings or blades are also applicable to
centrifugal pumps.
1000

page_text: Improvements in High Gauge Centrifugal Fans, and Fittings for
same, Applicable also to Centrifugal Pumps.
I, GEORGE MARIE CAPELL of Passenham near Stony Stratford, in the County
of Buckingham, Clerk in Holy Orders, 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:
The present invention relates to certain improvements in high-gauge centrifugal
fans and their fittings and is also applicable to centrifugal pumps.
Experience has shown that the form of wing or vane for such fans to give the
highest water gauge or manometric effects, is that curved in the direction of
rotation, or in other words, that in which a concave surface is opposed to the
air in front of it as the fan revolves, but with this form the mechanical or
useful effect is found to be low; and, on the contrary, a fan with curved wings
or vanes moving with their convex surface towards the direction of rotativa,
produces an opposite effect, giving a lower water gauge but higher useful effect.
The object of the present invention is to construct a high-gauge centrifugal
fan that will yield the most efficient combined results.
"
I will now proceed to describe my invention with reference to the accompanying
drawings forming part of this Specification, in which :-
Figure 1 represents my improved high-gauge centrifugal fan in central section
made on a plane parallel to its face.
Figure 2 represents my improved high-gauge centrifugal fan in central section
made on a plane at right angles to its face.
་
Figure 3 represents, in central section on a plane parallel to its face, my
improved high-gauge centrifugal fan as preferably constructed for use as a
centrifugal pump.
Figure 4 represents, in central section on a plane at right angles to its face,
my improved high-gauge centrifugal fan as preferably constructed for use as a
centrifugal pump.
Figure 5, represents in sectional elevation my improved fan mounted in an
improved form, of conical wall-box which forms also an air guard to inlet.
Figure 6 is an end elevation to my improved form of conical wall-box.
Similar reference letters indicate the same parts throughout the different
views.
A is the forward blade of the compound outer wing or vane, B is the rear
blade of the compound outer wing or vane, C is the space between the outward
extremities of the blades A, B, of the outer wings, D inlet circle, E is the boss,
F are the inner wings, G is the conical wall-box, H is the fan shaft or axle, I is
the air inlet, J is the masonry supporting the wall-boxes G, K indicates the
juncture of the blades A and B, L indicates the centre of the curve for the
blade B, M indicates the centre of the curve for the blade A, b indicates the
rounded corners of the fan when used as a pump.
According to my invention I form each outer wing or the portion of the wing
nearest the periphery of the fan, of two blades A, B, placed back to back.. One
of these blades, B, may be a straight one but preferably both are curved in
contrary directions, and united across the width of the fan at a point about
midway between the inlet circle and the periphery of the fan, as shown. I do
not wish to confine myself to any particular radii or centres for the curvature of
these blades but those which I have so far found to answer the purpose best are.
struck with a radius of about one fourth the diameter of the fan, for the blade A,

page_text: from a centre at M outside the periphery, of the fan, and, for the blade B, from
a centre at L; and in some cases as mentioned above the blade B may be straight.
The space between the blades at the periphery may either remain open or
be closed if desired to prevent eddies which the action of the fan may give
rise to.
This compound outer wing or vane may be used in conjunction with either
straight or curved inner wings, or that portion of the wings nearest the axle of
the fan, and any suitable number of these compound wings or vanes may be
employed in one fan.
The fan may be constructed with the usual bosses and axle, and, according
to requirements, with or without casing and side discs, and when used for
ventilating mines, may be used with special evasee outlets. The improvements
above described in connection with fan-wings are also applicable to pumps.
When the fan is to be employed as a pump the modification in the construction
is preferably that shown in Figures 3 and 4. Compound outer wings A, B, of
various curves to suit different lifts are employed. The corners bare preferably
rounded as shown to suit the water flow. The spaces C are closed in. The boss E is
joined to the inner wings F. These inner wings may be either complete wings or
detachable as shown at N.
The other improvement in the fittings is illustrated in Figures 5 and 6 namely
an improved form of wall-box bearing G for the fan-shaft, the object of it being
to shorten the shafts H in high-gauge fans with outside bearings. In high-
gauge mine fans great difficulty has been experienced in entering the fan drifts
for the purpose of oiling or inspecting the bearings, owing to the great velocity
of the air flow at the inlet I rendering the approach to the bearings dangerous.
In order to obviate this, I make a bearing frame or wall-box G of a hollow conical
form resting on the masonry J of the air passage and hanging over or projecting
into it towards the fan inlet I. In this hollow cone G are placed the bearings
which are then accessible from the outside of the air passage, and being closer
together it will be seen that this arrangement also enables a shorter shaft to be
used for the fan, which reduces vibration when running at high speed.
My improved fan whether employed as fan or pump may consist of the compound
outer wings A, B, either with or without the addition of the inner wings F. The
inner wings when used may dip into the inlet circle D and be secured to the
outer compound wings as shown.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. A high-gauge centrifugal fan or pump having compound outer wings or
vanes consisting of two curved blades fastened together back to back, and either
with or without the combination of inner wings, substantially as and for the
purpose herein described and shown.
2. A high-gauge centrifugal fan or pump having compound outer wings or
vanes consisting of two blades, one curved and the other straight, fastened together
back to back, and either with or without the combination of inner wings, sub-
stantially as and for the purpose herein described and shown.
3. A compound outer-wing for a centrifugal fan or pump, consisting of two
blades fastened together back to back, the space between their divergent extremities
being either open or closed-in, substantially as herein described and set forth.
Dated this 12th day of August 1897.
PHILLIPS & LEIGH,
No 22 Southampton Buildings, Chancery Lane, London, W.C.
Agent for the Applicant.