Year: 1898

page_text: Date of Application, 19th Apr., 1898-Accepted, 4th June, 1898
A communication from THE PRATT PROCESS COMPANY, a Corporation organized and
existing under the laws of the State of Georgia, one of the United States of
America, and doing business at Atlanta, Georgia, and elsewhere.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, Holborn Circus, in the County
of Middlesex, Chartered Patent Agent, 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:-
This invention relates to rotary fans or exhausters.
The object is to provide an exhauster, adapted, particularly, in use, for handling
corrosive gases, either acid or alkaline, in which those parts subjected to direct
contact with the gases will be shielded from the corrosive action thereof; to provide
an exhauster having a casing of such construction' as to permit of easy and ready
access to the interior thereof, for the purpose of removing the blast-wheel, without
disturbing the permanent parts of the apparatus; to provide simple and effective
means both for holding the blast-wheel on the shaft and for shielding such means
from the action of the gases; and, finally, to provide an exhauster which shall be
simple in construction, durable and efficient in use, and which may be constructed
at a nominal figure.
In an exhauster characterized by this invention, a blast-wheel casing is provided
cast, or made by hand, of an alloy of lead and antimony, or other non-corrosive
materials. This casing is constructed of two parts, one part of which may be
designated as the stationary portion, and the other part as the removable portion.
The stationary portion is provided with the usual entry and exit flues, and these
latter, for the purpose of preventing escape of gases at these points may be burned
to the stationary portion of the casing, or may be provided with flanges to be
bolted to similar flanges on the said stationary portion. The stationary portion is
also provided with a suitable stanchion, on one side, opposite the entry-flue, which
supports the boxes or bearings in which works the blast-wheel shaft, the said shaft
being provided with a non-corrosive protecting-sleeve to shield the shaft against
the corrosive action of gases which may escape at this point and which would tend
rapidly to destroy the shaft. This stationary portion may be constructed of two
sections, as usual (though it may be made in one or any number of sections) and be
held together by bolts passing through flanges provided for the purpose, an acid-
tight joint being provided by interposing a suitable packing or cement between
the flanges, or by burning these parts together, as will be understood.
The removable portion of the casing may occupy the upper part thereof to one
side the entry or exit flue or both, as may be preferred, and is secured to
said stationary portion by bolts passing through flanges provided for the purpose,
suitable packing or cement being interposed between the flanges to present a tight
joint, this removable portion, as also the stationary portion, being provided on one
side with a section of a stuffing-box in which the sleeve-covered shaft works. The
removable portion is of such size with relation to the stationary portion that upon

page_text: its removal the interior of the casing will be exposed to view, so that, if desired, the
blast-wheel may be removed.
The blast-wheel is to be constructed of any suitable non-corrosive materials, and
should possess sufficient rigidity to present the requisite strength for speed, without
danger of losing its shape. This wheel may be secured to the shaft by which it is
driven in any suitable manner, as by casting the wheel around a right- and left-
hand threaded bushing, which may also be provided with keys, and securing this
bushing to the shaft by a key or by so shaping the shaft and the bushing as to
prevent the turning of the shaft therein, or, the keys may be dispensed with, and
the bushing serve to hold the wheel in place; or, the bushing may be simply
roughened or have projecting points, which will sink into the metal of the wheel
when the same is cast around it; or, the shaft may be rounded and fixed in the
bushing by an ordinary key; or the key may be dispensed with, and the shaft may
be made square, triangular, hexagonal, or otherwise, in cross-section, the bushing
being shaped to fit the shaft, or the hub may be soldered to the shaft.
The removable portion of the casing may be constructed in one or more sections,
preferably in one, and the flange or flanges by which it is secured to the stationary
portion may extend only to the entry or exit flues, or may extend over and join
similar flange on either one of these flues, or both.
a
In order to facilitate access to the blast-wheel, the same is free from any support
at one end, so that by removing the section of the casing just described, the portion
of the stuffing-box attached will come apart with it and the shaft and its blast-
wheel may be lifted out.
The shaft on which the blast-wheel is mounted works in bearings entirely
removed and free from the casing, so that they will be readily accessible for the
purpose of oiling, or otherwise.
Further and more specific details of construction
described.
will be hereinafter
In the accompanying drawings, forming a part of the specification, and in which
like letters of reference indicate corresponding parts, a form of embodiment of
this invention is illustrated although it is to be understood that other forms
of embodiment thereof may be employed, without departing from the spirit of
this invention.
set
In these drawings:
Figure 1 is a view in side elevation, displaying the exhauster as it appears when
up for use, the view being taken from the pulley-side of the casing;
Figure 2 is a view in plan;
Figure 3 is a view in end elevation;
Figure 4 is a view in elevation of the blast-wheel;
Figure 5 is a view in vertical section, showing, more particularly, the manner in
which the wheel is secured to the shaft.
Figure 6 is a detached view of the right-and-left-hand threaded bushing for
holding the wheel in place on the shaft; and
Figure 7 is a view in transverse section, showing, more particularly, the manner
in which the sections of the casing are joined.
Referring to the drawings, A designates the stationary portion of the casing,
and A² the removable portion thereof. The stationary portion is provided, on one
side, with an entry-flue a, and at its periphery with an exit-flue a², as usual, it
being understood that my correspondents do not limit themselves to the precise
location of these flues, as their position may be altered, without departing from the
spirit of this invention. The stationary portion of the exhauster is constructed of
one or more sections, and, if more than one are employed, they are secured
together by flanges a³, through which pass bolts at, for holding the parts assembled,
these flanges being packed, cemented, or burned together, in any well-knowu
manner, to present a tight joint. In this form of the invention, the stationary portion
is shown provided with legs or standards a5 for supporting the casing, but it is to

page_text: be understood that these legs may be dispensed with, and the casing supported
upon an ordinary base.
The removable portion A² may be in one piece, or it may be made of more pieces, and
is provided with flanges a on its body and with side-flanges a', mating with similar
flanges as on the stationary portion of the casing, and through these latter flanges
bolts are passed for holding the two parts assembled, any suitable packing, such as
indestructible putty, or the like, being placed between the flanges for the purpose
of making a tight joint. It is to be understood that the location of these
flanges a, a, may be changed, and may be either straight or curved. The
flanges a are also to be burned, packed, or cemented together, to present a tight
joint. The flanges a, as, are to be so formed as to avoid interference with the
entry-flue on that side of the casing, and, on the opposite side of the casing, these
flanges are to be curved into the shaft-opening, as at a, and be provided,
each, with a section of a stuffing-box for the shaft. The objects of curving or pro-
jecting the portion aº of the casing in toward the entry-flue are two-fold: First,
to have the bearing or stuffing-box as near the blast-wheel as possible to reduce
leverage and thus prevent wobbling and eccentric movement of the wheel with
attendant vibrations and consequent injurious racking of the casing; and, second,
to have the portion a correspond with the concavity of the disc of the blast-wheel
to prevent, as far as possible, escape of gases from the casing through the stuffing-
box, by causing the gases to be projected practically from one side of the blast-
wheel.
This peculiar formation of the casing is highly advantageous and increases the
usefulness and life of the device.
As will be noted by reference to Fig. 3, the inner end of the blast-wheel drive-
shaft, or that end next to the inlet-opening, is not supported, as it is essential that
the inlet-flue should be free from any obstruction; and this arrangement, due to
the weight of the blast-wheel, puts a great strain on this end of the drive-shaft,
and without the novel means for supporting the same, as shown, the leverage
would be so great that, in a short time, the wheel would wobble and have
eccentric movement, and thereby tend, rapidly, to destroy the bearings.
By the peculiar manner of curving the sides of the casing inward around the
shaft on the pulley-side to present two members of a stuffing-box, admission of air
from without or escape of gas from within is obviated, and, by having the journal-
boxes as near the plane of rotation of the wheel as possible, the wheel is supported,
braced, and steadied, so that, under all conditions of use, it will run in a true
circle. It will be apparent that by removing the bolts for holding the
flanges a, as, together, and detaching the removable portion of the casing, access
to the interior of the casing may be had, without interfering with the fixed parts
of the casing, that is to say, with the stationary portion thereof, and with the entry
and exit flues.
The blast-wheel B is to be made of any suitable material, combining strength
with non-corrosive qualities, and may be of any preferred shape for the purpose.
The hub of this wheel has, in this instance, fitted within it a bushing C
provided with right- and left-hand threads, this bushing being held in place
within the hub by having the metal thereof cast around it. The shaft D of the
blast-wheel is provided at one end with a collar d against which the bushing C
and the outside projecting end of the hub abut, said shaft being, in this instance,
held against turning by being united, as by being keyed into the bushing, the
bushing being made, really, a part of the blast-wheel hub; or by lightly tinning
the surface of the same before the blast-wheel is cast around it. A. key may
be inserted between the bushing and the shaft, and similar keys c between the
bushing and the hub, sɔ as so hold these two securely assembled, but, as before
stated, the particular manner of holding the blast-wheel in place on the shaft
may be varied at will. The outer end of the shaft is threaded and on this threaded
portion are turned two nuts d³, dt, the latter constituting a locking-nut, these
nuts serving to force the hub tightly against the collar d, and thereby, further,

page_text: prevent the wheel from turning on the shaft. In order to protect the end of the
shaft carrying the nuts d³, d, and also the nuts, from the corrosive action of the
gases, a cap 62 is burned on to the hub of the blast-wheel and incloses these
nuts. When the wheel is to be removed from the shaft, this cap may be cut
off and the nuts and key removed in any obvious manner to effect release of the
wheel.
The shaft D is supported exteriorily of the casing upon a bed E having
journal boxes e in which the shaft works, these boxes being provided
with suitable openings 2 by which oil may be supplied to the shaft, the
latter, also, being provided with a pulley by which the wheel may be
driven.
In order to remove the liquids resulting from condensation of gases, a drip-
pipe is provided at the bottom of the casing by which the liquid may be removed
as rapidly as generated, and caught in a suitable receptacle, as G.
It is to be understood that I do not limit my invention to the materials and
to the particular use described, as the apparatus is adapted for handling
gases other than those described, or for air. In the latter instance, the
casing may be made of wood, paper, or other suitable materials, instead
of metal.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondents and in what manner
the same is to be performed, I declare that what I claim is :-
1. The exhauster, substantially as and for the purpose described.
2. An exhauster-casing comprising a stationary portion provided on one side with
an entry-flue and at its periphery with an exit-flue, and a peripherally-remov-
able portion extending to the axis of and impermeably secured to the stationary
portion, the removable portion being of such size that, when removed, an open-
ing is left, through which the blast-wheel and its shaft can be taken out with-
out detaching either of the flues, substantially as described.
3. An exhauster-casing comprising a stationary portion provided on one side
with an entry-flue and at its periphery with an exit-flue, and a peripherally-
removable portion extending to the axis of and impermeably-secured to the
stationary portion, a blast-wheel mounted in the stationary portion opposite the
entry-flue, and a stuffing-box arranged partly on the stationary portion and
partly on the removable portion for preventing admission of air from without or
escape of gas from within, the removable portion of the casing being of such
size that, when removed, an opening is left, through which the blast-wheel and
its shaft can be taken out without interference with either of the flues, sub-
stantially as described.
4. An exhauster comprising a stationary portion having an entry- and an
exit-flue, and a removable portion, the sides of the two portions, opposite the
entry-flue, being curved or bent inward to present two members of a stuffing-
box, substantially as described.
5. An exhauster comprising a stationary portion having an entry and an exit
flue, and a removable portion, the sides of the two portions, opposite the entry-
flue, being curved or bent inward to present two members of a stuffing-box, a
shaft running in the stuffing-box, and a blast-wheel supported on the shaft in
juxtaposition to the stuffing-box, substantially as described.
6. An exhauster comprising a stationary portion having an entry and an exit
flue impermeably secured thereto, and a removable portion, the removable por-
tion being adapted to be separated from the stationary portion without inter-
ference with any of the parts of the latter, the sides of the two portions,
opposite the entry-flue, being curved or bent inward to present two members of a
stuffing-box, a blast-wheel mounted within the casing and having a shaft running
in the stuffing-box, the end of the shaft, opposite the entry-flue, being unsupported,
substantially as described.

page_text: 7. An exhauster comprising a stationary portion provided on one side with an
entry-flue and at its periphery with an exit-flue, and a peripherally-removable por-
tion extending to the axis of and impermeably. secured to the stationary portion, the
removable portion being of such size that, when removed, an opening is left, through
which the blast-wheel and its shaft can be taken out without interference with
either of the flues, and a drip-pipe connected with the casing, substantially as
described.
8. In an exhanster, a shaft, a blast-wheel secured thereto by solder or the like,
nuts secured on one end of the shaft for holding the wheel in place, and a non-
corrosive cap or casing inclosing the nuts and the end of the shaft, substantially as
described.
9. In an exhauster, the combination with a shaft, of a blast-wheel, a right-and-
left-hand threaded bushing secured to the hub of the wheel and to the shaft, and
keys inserted between the bushing and shaft, substantially as described.
BOULT & WADE,
Agents for the Applicant.