Note: Descriptions are shown in the official language in which they were submitted.
12~36658
The present invention relates to a fluid agitator which
stirs fluid, that is liquid and gas or the like, in a closed
space.
Fluid agitating i5 sometimes required under increased
pressure, under reduced pressure or at high temperatures in a
closed space, for example in a reaction chamber, an autoclave, a
rubber vulcanizer, an electric furnace, a heat treatment furnace,
a culture chamber, or the like. The fluid agitation in such
closed space is required to uniformly and promptly to distribute
the temperature and/or the humidity thereof, or to activate the
reactive fluid.
Apparatus for achieving such agitating includes a motive
means, e.g. a motor or the like equipped outside of the closed
space, and a rotating shaft attached to the motor, the shaft
being provided with an agitating blade. The rotating shaft
passes through a partition into the closed space and stirs the
fluid therein by means of the agitating blade.
With such apparatus, a hole must be formed in the partition
to enable the shaft to pass through, and a seal must be provided
around the shaft. A mechanical seal, a labyrinth seal, an oil
seal, a gland packing or the like are generally utilized for the
sealing of such rotating shaft. As is well known, such shaft
sealing devices are not able completely to prevent leakage of the
fluid from the closed space. Where the inner pressure or the
temperature of the closed space is very high, and/or where the
shaft rotates at high speed, such sealing devices cannot retain
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their sealing ability. This lowers the reliability of the
equipment using it. In fact, accidents occurred where
lubricating oil, which has leaked from a double type mechanical
seal into the inside of the closed space, was subjected to high
temperature and ignited.
Thus, it was not generally possible to obtain satisfactory
equipment in which Eluid required to be stirred was disposed in a
closed space. There are many fields, e.g. a high temperature and
pressure moisture curing vessel for light bubble concrete, where
the use of an agitating fluid in the closed space is not
practiced, notwithstanding the fact that agitation of such fluid
would be clearly effective and advantageous.
If a fluid agitator could be provided which substantially
agitated the fluid under high temperature and high pressure
conditions in a closed space without accidents, e.g. without
leakage and/or ignition, it would be applicable for many fields
of industry.
Accordingly it is an object of one aspect of this invention
to provide a fluid agitator which does not utilize a rotating
shaft passing through a partition of a closed space within which
the fluid to be agitated is disposed.
It is an object of another aspect of this invention to
provide a fluid agitator which can agitate the interior of a
closed space with high reliability under condition of high
temperature, high pressure and/or high humidity.
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It is an object of a further aspect of this invention to
provide a fluid agitator which can agitate fluid in a closed
spacQ at high speeds without significant leakage of the fluid out
of the closed space.
~ y one broad aspect of this invention, a fluid agitator for
agitating liquid, gas or the like in the closed space, is
provided, comprising a motor including a stator coil sealed in a
sealing chamber, an agitation blade connected to the driving
shaft of the motor, and a bearing which has resistance to high
temperature and/or high humidity supporting the driving shaft.
In one embodiment thereof, the sealing box may be provided with a
cooling device to cool the inside thereof. In another embodiment
thereof, the motor preferably comprises: a stator having an
almost-square, ring shape with open edges; a stator coil wound
around the stator and sealed by the sealing vessel; and an
armature placed between the open edges of the stator.
With such construction, according to one embodiment of the
invention, the motor safely enables agitation without problems in
a high temperature, and/or high pressure, and/or high humidity
atmosphere of the closed space since the stator coil having
slight resistance to high temperature, and/or high pressure,
and/or high humidity is set and sealed in the sealing chamber.
Consequently, the interior of the closed space can be reliably
stirred without the need for the passing o~ a rotating shaft
through a partition of the closed space.
By another broad aspec-t of this invention, a fluid agitator
is provided including a turbine chamber which is installed in a
closed space. A turbine blade i3 set :in the turbine chamber. A
fluid supply is provided including means to introduce the fluid
into the -turbine chamber for driving and rotating the turbine
blade. The fluid which has driven the turbine blade may be
exhausted into the outside of the closed space by an appropriate
discharging device, or may be leaked into the closed space, such
leakage does not give rise to other problerns. The turbine blade
is connected -to a transmission which transmits the rotation of
the turbine blade to the outside of the turbine room. The
agitation blade is connected to th0 transmission outside of the
turbine chamber.
~lthough it is not required for the turbine chamber to be
perfectly sealed, and even though some leakage may be allowed to
the extent of the limit of the present art, it is preEerred to
minimize the leakage o the fluid into the turbine chamber or the
leakage oE the fluid for driving the turbine into the closed
space.
It is preferred that the agitating blade be connected to a
driving shaft, and that the driving shaft be supported by a
bearing having resi tance against high temperature and/or high
humidity. The agitating blade is connected to such driving
shaft.
i5~3
Furthermore, it is preEerred tha-t the bearing for the
driving shaft include a first ball ~hich i3 adap-ted to be in
sliding contact with an end face of the driving shaft, and at
least one secon~ ball which is adapted to be in rolling contact
~ith the firs-t ball.
Gas, air, inert gases, e.g. ~17, ~r, or the like, liquid or
steam can be employed as the fluid for driving the turbine blade.
Though a designat0d fluid may be supplied for driving the
turbine blade the fluid, gas or steam for pressurizing and/or
10 heatin~ the inside of the closed space may b0 u-tilized as such
driving fluid. Th0 pressure oE such gas or steam is reduced to
the prescribed value through a reducing valve for such driving
use. When such gas or s-team is used as the driving fluid, such
fluids may be introduced directly from the source without passing
through a reducing valve into the turbine chamber to drive the
turbine blade. The gas or steam which has been used Eor driving
the turbine may be leaked into the closed space to pressurize or
heat the inside thereof, or it may be exhausted out of the system
to heat or pressurize other equipment. The application of such
20 gas or steam for driving effectively reduces the operating cost
of the turbine system.
Such embodiment of the present invention provides efEective
agitation of the fluid in the closed space by introducing the
fluid for driving into the turbine room from the outside~ The
fluid rotat0s the turbine blade and the rotation is transmitted
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by the -transmission. to -the agitation blade which stirs the fluid
in the closed space.
In the accompanying drawings,
FIG. 1 i.5 an ~levational view in --;ection showing one
embodiment of the Eluid agitator oE an asp~ct of the present
invention;
FIG. 2 is a plan vie~ of the embocliment o:E FIG. 1;
FIG. 3 ancl FIG 4 are plan views showing an arrangement of
balls in a b~a.riny;
F'IG. 5 is an enlarged section view showing ano-ther
embodiment of the bearing;
FIG. 6 is an elevational view in sec-tion showing another
embodiment oE the agitator of another aspect of this invention;
and
FIG. 7 is an enlarged saction view showing the bearing part
of the embodiment of FIG. 6.
Refer:ring to the attached drawings, (X) indica-tes a closed
space, e.g. a chamber, a Eurnace or the lilce. (A) indicates a
fluid agitator of an embodiment of this invention in FIG. 1 and
FIG. 2. In FIG. 2, tha closed space (X) is omitted fo.r clarity.
Though the closed .space (X) is illustrated in FIGS. 1 and 2, as a
ractangular parallelepiped, it may be of any shapa; for exampls
it may be a ring shape.
The agitator (A) consists of a motor 1, an agit~ting blade
2, and a bearing 3. A stator coil 11 o~ the motor 1 is placed in
a closed space (X~. In this embodiment, the stator coil 11 is
5~3
set and sealed in a sealing chamber 13 made of stainless steel
which protects the sta-tor coil 11 from atmo3pheres of high
temperature, and/or high pressurs and/or high humidi-ty in the
clo~ed space (X). The sta-tor coil 11 and sealing chamber 13 hav~
the shape oE a rectangular ring ha~ing a hole in -the center,
through which a stator 10 passes. The stator 10 has a shape of
an almost-square ring with an open edge, whose end faces facing
each other are each formed in Q semi-circle. An arma-ture 12 is
installed between the end faces.
With such construction, the stator coil 11 is protec-ted by
the sealing chamber 13, which does not magnetically affect the
motor 1 because the sealing chamber 13 is not in-terposed between
the stator 10 and the armature 12.
The sealing bo~ 13 may be cooled according to demand. In
the embodiment shown, the sealing bo~ 13 is provided with two
co~munication pipes 16a and 16b which extend outwardly through
the partition of the closed space (X). The holes in the
partition through which the communication pipes 16a, 16b pass are
sealed by O-rings 19, 19 or other equivalent sealing means. The
communication pipe 16a is connected to a source of cooling gas
(not illustrated), and carries the gas to the sealing box 13 for
cooling the stator coil 11. The communication pipe 16b is for
the purpose of exhausting the cooling gas. The communication
pipe 16b may be open to the air or may b~ connected to a suction
pump (not illustrated) or the like~ The communication pipes 16a,
16b also serve as the extending pipes for a cord 17 of the stator
~X~665B
coil 11, from which the cord 17 projecl:s through a seal 18. The
sealing box 13 may be provided with a covering jacket or the like
over the outside, and may be cooled by a cooling gas introduced
therebetween. Man~ other embodiments i-or cooling the sealing box
13 can be employed within the scope of this invention.
The armature 12 is provided with eL vertically-extending
driving sha~t 14 which is supported by bearings 3, 3 at the top
and bottom ends -thereo~. An agitating blade 2 i~ ~ixed to the
upper part of the driving shaft 14. The agitating blade 2 is
made o-~ any metallic material which is resistant to high
temperature and/or high humidity. The bearings 3 consist of
supports 7, 7 which have a semi-spherical shape and include balls
8 th0rein. The supports 7 have holes therein which hold a
plurality o balls 8 which rotatably support the end of the
driving shaft 14 disposed therein. The upper support 7 is held
in a supporting box 4 by spring 5 which absorbs the vertical
movement oE the driving sha~t 14. The supporting box 4 includes
a foot 6 having a crank shape which supports the supporting box 4
on the stator 10.
In this embodiment, the bearing 3 has the inventi~e
construction which is resistant to high temperature and/or high
speed rotation without an oil-supply. As shown in Figs. 3 and 4,
the support 7 holds a plurality of balls 8. A second ball 8' is
disposed in rotatable contact with each of ball ~. The ball 8'
is placed in a cone-shaped groove 9 formed on an end face of the
driving sha~t 14. Thç driving shaft 14 is supported by the ball
~6~i5~
8' which is in rolling contact with groove 9. A material which
does not require lubricating oil and which has high wear and
corrosion resistance is preferably utilized for the support , and
balls 8,8'. For e~ample, carbon, SiC, cemented carbide,
sapphire, ceramics or the like may be utilized. The material mav
be selected depending on the characteristic and the temperature
of the fluid to be stirred. The number of the balls 8,8' and/or
of the packing of the balls 8,8' are optional. For example, Fig.
5 shows the embodiment where the driving shaft 14 has a pair of
supports 7, one at each upper and lower end thereof and the balls
8 are packed in three steps, that is, the balls 8 are placed in
each oE the supports 7 and the ball 8' is placed between the pair
of supports 7 and in rolling contact with balls 8.
The inventive bearing having the construction mentioned
above does not need an oil supply and is wear-resistant because
the amount oE rolling contact of the balls is less than that of
the conventional pivo-t bearing. Consequently a high PV value is
obtained with such bearing in a high temperature atmosphere or
liquid, and the driving shaft 14 can be resistant to high speed
rotation.
The material of the driving shaft 14, of the armature 12 and
of the stator 10 may be selected depending on the atmosphere in
the closed space (X). 15 indicates the shading coil in Fig. 1
and 2.
In such construction, since the stator coil 11 which is
least resistant to high temperature, and/or high pressure and/or
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- 10 -
high humidity is set and sealed in the sealing box 13, the motor
1 may provide rotation without problems in such atmosphere of
high temperature, and/or high pressure, and/or high humidity
and makes the agitating blade 2 effectively agitate the fluid in
the closed space (~). When cooling of the sealing box 13 is
carried out, the heat resistance is further increased. Moreover,
since the sealing box 13 does not interfere with the magnetic
field between the stator 10 and the armature 12, and does not
magnetically affect them, the power of the motor 1 i5 the same as
that of an ordinary motor. The bearing which is resistant to
high temperature, and/or high pressure and/or humidity without an
oil supply bears the driving shaft 14 so that the driving shaft
14 can rotate without problems and maintains substantial stirring
by the agitating blade 2.
Referring now to Figs. 6 and 7, another embodiment of the
invention is shown. In Fig. 6, a fluid agitator (~) of one
aspect of this invention is installed in the closed space (X)
which is provided with the fluid to be stirred. The agitator (B)
is cylindrical in shape, whose under part is a turbine chamber
21. The upper part constitutes a space for the agitation blade
25 to rotate therein.
A turbine blade 22 is furnished in a turbine chamber 21 so
as to rotate horizontally therein by means of driving fluid for
driving the turbine blade 22 supplied from an injection nozzle 30
having a small bore. The injection nozzle 30 is set into the
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inner side-wall of the turbine chamber 21 and is connected with a
introduction pipe 32 through a conduit hole 31 which passes
through the bottom of the turbine chamber 21. The introduction
pipe 32 extends out of the closed space (X) passing through the
wall of the closed space (X), and is connected with a fluid
source (not shown) through a control valve 33 and a condenser,
pump, blower or the like 34. The control valve 33 is controlled
by a pressure controller 27 to be described hereinafter. The
injection nozzle 30, the conduit hole 31, the introduction pipe
32, the control valve 33, the condenser, pump, blower or the like
34, and the fluid source constitute a fluid supply device 23.
In this embodiment, the fluid, which has driven the turbine
blade 22, is exhausted out of the turbine chamber 21 to the
outside of the closed space (X). A discharge hole 35 is formed
in the bottom of the turbine chamber 21, which is connected to a
discharge pipe 36 which passes through the wall of the closed
space (X) and extends outside of it. The discharge pipe 36 is
provided with a control valve 37 which is also controlled by the
pressure controller 27. The fluid which has driven the turbine
blade 22 is exhausted through the discharge hole 35, the
discharge pipe 36 and the control valve 37. It is easy
completely to seal the part of the closed space (X) where the
introduction pipe 32, the discharge pipe 36 pass through, and to
prevent fluid leakage from the closed space (X) because the
introduction pipe 32, and the discharge pipe 36 are not
rotatable, but in the other hand, are stationary.
~6~S~
The -turbine blade 22 is secured vertically on the driving
shaft 2~ which is set in the turbine chamher 21 and is supported
by bearings 26,26 at each upper and lower end thereof. The top
and bottom of the turbine chamber 21 where the driving shaft 24
passes through is provided w:ith a b0ari:ng and shaft seal 40,40 to
improve the sealing perEormance of the turbine chamber 21. Many
embodiments rrlay be employed as the beariny and shaft seal 40; for
example, a labyrinth seal with a bushing is utilized in Fig. 6
The ~aterial oE the bearing and shaft seal 40 is preferably a
solid-lubricant, e.g. carbon, ceramics or the like, where it is
10 used in th0 high temperature of the closed space (X).
The agitation blade 25 is set at the upper end of tha
driving shaft 24. The driving shaft 24 transmits the rotation of
the turbine blade 22 to the agitation blade 25. The driving
shaft 24 is the means in this embodiment to transmit the rotation
of the turbine blade 22. The agitation blade 25 rotates
horizontally in rotation space 50 of the agitator (B). The
agitator (B) is provided wi-th an inlet 51, at one face -thereof
for the introduction of the fluid to be agitated into the
rotation space 50, and with an outlet 52 at the upp0r part of
20 side wall. The rotation of the turbine blade 22 induces flow of
the fluid in direction of the arrows in Fig. 6. The flow serves
to stir the fluid in the closed space (X). The setting position,
scale, number, and the like, of the outlet 51 and/or the outlet
52 may be determined depending on the position of the agitator
12866~
(~) in the closed space (X) and/or the amount of flow required
substantially to agitate the fluid.
The material of the turbine blade 22, the bearing and shaft
seal 40 or other elements may be select:ed at will. In the
embodiment shown, carbon material is ut:ilized so as to make the
turbine blade 22 light and the bearing and shaft seal 40 into an
oil-less bearing. Other materials, for example, organic
materials, inorganic materials, metals, or complex materials made
thereof, can be utilized if such material is light ~nd can be
lubricated without oil.
When the fluid to be stirred is a liquid, it is preferred to
use gas as the fluid for driving the turbine blade 22 and to
provide no discharge hole and pipe in the turbine chamber 21.
With such construction, the gas to drive the turbine blade 22
leaks from the bearing and shaft seal 40 into the sealed space
(X) and forms a bubble in the liquid and aids in agitation of the
liquid.
The introduction pipe 32 and the discharge pipe 36 each have
a pressure gauge 70 and 71 (respectively) which measure the
pressures P1,P2 thereof. A pressure gauge 72 to measure pressure
P3 is set in the sealed space (X). The pressure valves P1, P2,
and P3 input to a r~ressure controller 27 which controls the
control valves 33,37 so as to make the following pressure
condition: P1 = P2 + ~ P. Though ~ P may be determined
depending on the required speed of rotation of the turbine blade
22, a P is usually set at several atm. The pressure controller
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27 also controls P2 to be almost equal to P3 in order to prevent
the fluid which is to be stirred from leaking into the turbine
chamber 21 through the bearing and shaft seal 40 or to prevent
the fluid which is used to drive the turbine blade 22 from
invading into the sealed space (X).
Referring now to Fig. 7, a bearing is shown which has also
the inventive construction which is resistant to high temperature
and/or high speeds of rotation without oil supply. In the same
manner as the construction shown in Figs. 3 and 4, the supports
60,60 hold a plurality of balls 61' in rotational contact with
balls 61 in a well therein. The ball 61' is placed in cone-
shaped groove 41, which is formed on each end face of the driving
shaft 24. The ball 61' supports the driving shaft 24 in sliding
contact with the groove 41. A material which does not require
lubricating oil and which has high wear and corrosion resistance
is preferably utilized for the support 60 and/or for the ball 61.
Examples of such material include carbon, SiC, cemented carbide,
sapphire, ceramics or the like. The material may be selected
depending on the characteristics and the temperature of the fluid
to be stirred. The number of balls 61,61' and/or the stacking of
balls 61,61' are also optional. In the same manner shown in Fig.
5, such construction may be characterized by the driving shaft 24
having a pair of the supports 60 and having the balls stacked in
three steps; that is the balls 61 are placed in each support 60
and the ball 61' is disposed between the end of the driving shaft
24 and the pair of balls 61 in the support 60.
1~86G58
The lower support 60 is vertically movable and is supported
by the spring 62 in order to absorb such movement as caused by
the heat of expansion of the driving shaft 24.
The inventive bearing having the construction mentioned
above does not need any oil supply and is wear-resistance because
the amount of sliding of the ball 61 is less than that of the
conventional pivot bearing. Consequently a high PV value is
obtained with such bearing in a high temperature atmosphere, and
the driving shaft 24 can be resistant to high speed rotation.
In such construction, the turbine blade 22 rotates by
supplying the fluid, e.g. air, from the fluid supply 23, and
simultaneously rotates the agitation blade 25, which induces
stirring flow of the fluid i~ the closed space. There is no
significantleakage of the fluid out of the closed space, because
such construction includes no rotating shaft passing through the
partition of the closed space (X).
