FIELD
[0001] The invention refers to a cavitation device comprising a rotor arranged to rotate
about a rotation axis and a stator, the rotor and the stator each comprising teeth
arranged along a circle, the teeth of the rotor and the teeth of the stator having
cavitation surfaces facing each other and defining a gap between them in order to
induce cavitation in a liquid flowing therethrough.
BACKGROUND
[0002] Cavitation devices are used to induce cavitation in a liquid. Cavitation is the formation
of vapor cavities in a liquid that are the consequence of cavitational forces acting
upon the liquid. Cavitation usually occurs when a liquid is subjected to rapid changes
of pressure that cause the formation of cavities where the pressure is relatively
low. When subjected to higher pressure, the voids implode and can generate an intense
shockwave. The maximum pressure amplitude caused by an implosion can reach several
thousand N/cm
2. Since the shock waves formed by collapse of the voids are strong enough to cause
significant damage to moving parts, cavitation is usually an undesirable phenomenon.
However, there are numerous applications, in which cavitation is caused to happen
on purpose in order to treat liquids. For example, in chemical engineering cavitation
is often used to homogenize and break down suspended particles in a colloidal liquid
compound. Further, cavitation may also be used in order to purify water. In cavitational
purification devices the extreme conditions of cavitation can break down pollutants
and organic molecules. In such applications, particles contained in the liquid are
destroyed as a result of the tensile stress that is created by the negative pressure
following the shockwave.
[0003] Numerous embodiments of hydrodynamic devices for the creation of cavitation are known.
These embodiments comprise a casing with a liquid inlet and an outlet for the treated
liquid, wherein a rotor and a stator are concentrically arranged within the casing,
the rotor and the stator comprising concentric rows of cavitation elements (e.g. in
the form of blades). Instead of a rotor and a stator two rotors may be used that are
rotating relative to each other.
[0004] A rotor-pulsation device is described in
RU 2124935 C1. The rotor-pulsation device comprises a casing having an inlet and an outlet, in
which a rotor disk and a stator disk with toothed elements located on alternating
concentric circles are arranged. The toothed elements of one or several concentric
circles of the rotor or the stator disks are offset by an amount that provides an
overlapping of open sections between adjacent toothed elements of adjacent pairs of
concentric circles of rotor and stator disks, while the sections of any neighboring
pair of the same disks are open.
[0006] An essential disadvantage of hydrodynamic cavitation devices such as those described
above is that the cavitation intensity (cavitation quantity) is not uniform in the
entire device. The known devices are constructed such that the cavitation elements,
such as the toothed elements, are arranged on the rotor and on the stator in concentric
rows, from the center to the periphery, and thus at different radial distances from
the rotation axis of the rotor. The circular velocity of the cavitation elements increases
with increasing distance from the rotation axis. Since the cavitation intensity strongly
depends on the circular velocity of the cavitation element, the construction of the
known cavitation devices results in that the cavitation intensity increases with increasing
radial distance from the rotation axis. Under these circumstances, it is not possible
to achieve a controlled cavitation process.
[0007] In order to increase the overall performance of the known cavitation devices, it
would be necessary to increase the power of hydrodynamic oscillations; the power of
hydrodynamic oscillations depends on the flow speed of the liquid flowing by the non-uniform
disk surfaces. This is achieved by increasing the number of rotations of the rotor.
Known models generate cavitational flow in the whole volume of the liquid, but the
power of hydrodynamic oscillations in it is restricted by the fact that the maximum
circular velocity occurring at the outer peripheral region of the rotor must not exceed
a specific limit value. When increasing the movement speed of the liquid relative
to solid surfaces of the rotor or the stator by more than 25 m/s, there is a sharp
increase in cavitational erosion that leads to accelerated wear of the rotor and the
stator. Therefore, the rotation speed of the rotor cannot be increased to exceed the
limit value occurring at the outer peripheral region of the rotor, while in inner
regions closer to the rotation axis of the rotor, the full potential of the cavitation
device is not tapped.
[0008] Another essential shortcoming of known cavitation devices is the occurrence of beats
(unstable pulsations) of pressure of the processed liquid and beats of current intensity
in the circuit of the electromotor drive while operating under cavitational or close-to
cavitational modes. This shortcoming is caused by the fact, that in known cavitation
devices the quantity of cavitation elements of the rotor and the stator multiples
by 2,3 or 5. When the gaps of the cavitation elements coincide while the rotor is
spinning, there is an emission of resonant pulsating flows of the treated liquid going
out in radial direction. This leads to pulsations of hydrodynamic rotational resistance
of the rotor; pressure pulsations (in the range of ±30% and more) in output pipes
of the device; and current/flow intensity pulsations (in the range of ±30% and more)
in the electrical circuit of the electromotor drive. As a result, there is a decrease
in efficiency of the cavitational force on the processed liquid, an increase in energy
capacity of the process, a worsening of conditions, and a shortening of the working
life of the cavitation device.
[0009] Document
US-A-1 487 208 discloses a cavitation device in accordance with the preamble of claim 1.
SUMMARY
[0010] Therefore, it is an object of the instant invention to provide an improved cavitation
device that overcomes the shortcomings of the prior art cavitation devices.
[0011] In order to solve this object, the invention provides a cavitation device of the
initially defined type, in accordance with the features of claim 1, wherein the rotor
comprises at least two circular rows of radially outwardly protruding teeth, the at
least two circular rows of the rotor being arranged parallelly having the same radius
and arranged at an axial distance from each other so that an annular cavity is formed
between each two adjacent rows, wherein the stator comprises at least one circular
row of radially inwardly protruding teeth, wherein the teeth of each row are arranged
at a circumferential distance to each other so that a chamber is formed between each
two subsequent teeth in a row, wherein the teeth of the stator are arranged to protrude
into the annular cavity between the at least two rows of the rotor, so that the chambers
of the at least two rows of the rotor and the chambers of the at least one stator,
when axially aligned with each other, form channels extending parallel to the rotation
axis of the rotor.
[0012] The inventive construction results in that all cavitation elements (i.e. the teeth
of the rotor and the teeth of the stator) are located at the same radial distance
from the rotation axis, so that uniform conditions with regard to the creation of
cavitation are observed in the entire cavitation device. This allows to adjust the
cavitation parameters in the desired manner and in particular an optimization of the
cavitation intensity.
[0013] In the context of the instant invention, the terms "stator" and "rotor" serve to
differentiate between two elements that have a rotational speed relative to each other.
In some embodiments the stator may be static, while the rotor rotates relative to
the stator. However, the term "stator" does not mean that the stator must necessarily
be a static element. Rather, in some embodiments of the invention, both the rotor
as well as the stator may be arranged in a rotatable manner. In particular, the rotor
and the stator may be driven to rotate in opposite directions.
[0014] In the inventive device cavitation is induced by the following mechanism. During
rotation of the rotor, in the moment when the teeth of the stator overlap the chambers
between the teeth of the rotor there is a sharp increase in pressure (direct hydraulic
shock). In the moment when the chambers between the teeth of the stator overlap with
the chambers of the teeth of the rotor, thereby forming channels extending parallel
to the rotation axis, a sudden decrease in pressure occurs, followed by the slowing
down of the movement speed of the liquid and the formation of hydrodynamic cavitation
in the liquid. In the course of hydrodynamic cavitation there is a formation of fields
of cavitational bubbles and cumulative micro-streams with a diameter of 5-200 microns,
moving at speeds 50 to 1500 m/s. When the liquid moves through the gaps between the
teeth, the movement speed decreases, pressure increases, and the cavitational bubbles
implode due to the bypass channels in the working chamber of the device. Pressure
in implosion points of cavitational bubbles can reach 1,5x10
3 MPa. When the teeth of the rotor overlap the chambers between the teeth of the stator,
the solid particles contained in the liquid are destroyed as a result of wedging forces
of cavitational micro-streams, and also under the influence of considerable pulling
stresses, arising on the surfaces of the solid particles.
[0015] With the inventive device, the cavitation intensity may be adjusted in a simple manner.
The cavitation intensity depends on the value and the frequency of pressure pulsations,
arising when the rotor teeth overlap the chambers of the stator. The frequency of
these pulsations can easily be increased by increasing the number of teeth in the
circular rows of teeth of the rotor and the stator. The number of teeth in a circular
row is only limited by the minimum width of teeth required for their structural stability
and by the width of outlet channels in the stator necessary for the complete outlet
of the processed liquid. Further, the frequency of these pulsations can be increased
by increasing the rotating speed of the rotor. The rotational speed of the rotor is
only restricted by the parameters of the bearing block of the rotor shaft (lubrication
conditions, permissible temperature and necessary resource of frictionless bearings)
and should not exceed 50 Hz (3000 rpm).
[0016] As mentioned above, the minimum configuration of the cavitation device comprises
at lest two rows of teeth arranged on the rotor and at least one row of teeth arranged
on the stator. However, the number of circular rows of teeth realized on the stator
and on the rotor may be increased depending on the circumstances. According to a preferred
embodiment of the invention the stator and the rotor each comprise a plurality of
circular rows of teeth, wherein the teeth of the rows of the stator protrude into
the annular cavity between the rows of the rotor and vice versa. Preferably, the stator
comprises at least five rows of teeth, preferably at least 7 rows of teeth.
[0017] According to a further preferred embodiment, the teeth of the rotor, in a longitudinal
section, have a profile that substantially corresponds to the profile of the annular
cavity of the stator, and vice versa. In particular, the cavitation surfaces of teeth
of the rotor and of the stator facing each other are parallel to each other and define
a gap between them that has a width of 0,3-1,7 mm, preferably 0,4-0,6 mm. Preferably,
adjustment means are provided for adjusting the width of the gap.
[0018] According to a preferred embodiment, the teeth of the rotor and of the stator, in
a longitudinal section, have a trapezoidal profile. In particular, the angle of inclination
of the side faces of the teeth is selected to be 15-20° relative to a plane extending
perpendicular to the rotation axis. Preferably, the trapezoidal profile of the teeth
of the rotor, tapers in a radially outward direction and the trapezoidal profile of
the teeth of the stator, tapers in a radially inward direction.
[0019] With regard to the number of teeth in each circular row of teeth an embodiment is
preferred, wherein the rows of the stator have the same number of teeth and the rows
of the rotor have the same number of teeth. In particular, all the teeth of the rotor
have the same shape and dimension and all the teeth of the stator have the same shape
and dimension, so that, in accordance with a preferred embodiment of the invention,
the rows of teeth of the stator, in a cross section thereof, are congruent, and the
rows of teeth of the rotor, in a cross section thereof, are congruent.
[0020] According to a preferred embodiment of the invention, the ratio of the circumferential
extent of each tooth to the circumferential extent of each chamber is 0,6-1,15.
[0021] A further preferred embodiment relates to the number of teeth in a circular row of
teeth of the stator in relation to the number of teeth in a circular row of teeth
of the rotor. According to a first alternative, the rows of teeth of the rotor have
the same number of teeth as the rows of the stator. This construction results in a
simultaneous formation of axial channels along the entire circumference of the rotor
when the chambers of the rows of the stator and those of the rows of the rotor get
axially aligned with each other. Upon further rotation of the rotor by a rotation
angle that corresponds to the width of the teeth, all teeth of the rotor will overlap
the adjacent chambers of the stator and all teeth of the stator will overlap the adjacent
chambers of the rotor simultaneously along the entire circumference.
[0022] Alternatively, the at least two rows of teeth of the rotor each have fewer teeth,
in particular one tooth less, than the at least one row of teeth of the stator. In
this embodiment an overlapping of the teeth of the rotor with the adjacent chambers
of the stator and vice versa at the same time along the entire circumference is excluded.
Rather, the overlapping position is assumed gradually along the circumference in the
course of the rotation of the rotor. This leads to a stabilization of the hydrodynamic
resistance to the rotation of the rotor, thus stabilizing pressure pulsations in outlet
pipes of the device and pulsations of current intensity in the circuit of the electromotor
drive, wherein the pulsations preferably do not exceed ±5%. The technical result is
a lowering of the noise level, an improvement of operating conditions and an increase
of the service life of the device.
[0023] In particular, the number of teeth in a row of the rotor is a prime number not less
than 20.
[0024] As to the flow of the liquid through the device, the following embodiments are advantageous.
Preferably, the stator encloses a circular cavity, in which the rotor is arranged
in a rotatable manner and which comprises a central inlet arranged coaxially with
the rotation axis of the rotor. Thus the feeding of the liquid into the device is
performed through a central inlet, that opens into the circular cavity. Inside the
circular cavity, the liquid is forced to flow in an outward direction to reach the
working region, in which it is subjected to cavitation while being pressed to flow
between the teeth of the rotor and the teeth of the stator. The liquid preferably
exits the stator in a radial direction and is collected in an annular chamber surrounding
the stator.
[0025] In order to impart a centrifugal force to a liquid, a preferred embodiment provides
that the rotor comprises impeller blades to direct liquid that enters the cavity through
the inlet radially outwardly to the chambers of the rotor and the stator. In this
way, the liquid is sucked up by the impeller through the inlet opening and the centrifugal
forces direct the liquid from the center of the cavity to the periphery, creating
a movement of the liquid in the axial channels that are formed when the teeth of the
rotor are aligned with the teeth of the stator.
[0026] According to the invention, the chambers of the stator each have a discharge opening
directed radially outwardly. In particular, the discharge opening opens into a radially
extending discharge channel, that has a cross section that preferably widens in an
outward direction. Due to the widening of the discharge channels, the effect of a
diffuser is obtained.
[0027] Under the influence of centrifugal forces the liquid contained in the chambers is
removed via the discharge channels, wherein the diffusor effect promotes a pressure
decrease, which in turn results in a collapse of cavitation bubbles in the liquid.
In particular, the collapsing proceeds from the discharge channels to the walls of
the annular chamber surrounding the stator, without contacting the walls. Thus, the
working organs and the casing of the device do not experience the destructive force
of cavitation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In the following, the invention will be described by reference to an exemplary embodiment
schematically illustrated in the drawings.
Fig. 1 is a longitudinal section of a first embodiment of a cavitation device,
Fig. 2 is a partial illustration of the rotor and the stator of the first embodiment
in a perspective view, with the rotor in a first position,
Fig. 3 is a perspective cross sectional view of the rotor and the stator with the
rotor in a second position,
Fig. 4 is a partial illustration of the stator in an inside perspective view,
Fig. 5 is an outside view of the stator and the rotor,
Fig. 6 is a front view of a second embodiment of the stator and the rotor,
Fig. 7 is a system comprising a cavitation device according to the invention.
DETAILED DESCRIPTION
[0029] Aspects of the present invention are disclosed in the following description and related
figures directed to specific embodiments of the invention. Those skilled in the art
will recognize that alternate embodiments may be devised without departing from the
spirit or the scope of the claims. Additionally, well-known elements of exemplary
embodiments of the invention will not be described in detail or will be omitted so
as not to obscure the relevant details of the invention.
[0030] It should be understood that the described embodiments are not necessarily to be
construed as preferred or advantageous over other embodiments. Moreover, the terms
"embodiments of the invention", "embodiments" or "invention" do not require that all
embodiments of the invention include the discussed feature, advantage or mode of operation.
[0031] In Fig. 1 a cavitation device 1 of the invention is illustrated comprising a substantially
cylindrical housing 2 having a flange connection 3 for connecting a feeding pipe for
feeding liquid to the inside of the device. The housing 2 comprises an inlet opening
4 that opens centrally into the cavity of the housing and is aligned with the rotation
axis 5 of the device 1.
[0032] A stator arranged inside the housing 2 is denoted by 6 and defines a cylindrical
cavity, in which a rotor 7 is arranged in a rotatable manner. The rotation axis of
the rotor 7 is denoted by 5. The rotor 7 is supported on a shaft 8, which is arranged
to rotate within a bearing 9. A sealing member is denoted by 10. The rotor carries
a plurality of impeller blades 11, in order to direct fluid that enters the cavity
through the inlet 4 radially outwardly towards the periphery of the rotor 7 and to
the stator 6. As will be explained with reference to Figs. 2 to 4 the fluid is subjected
to cavitation by cavitation elements of the rotor 7 and the stator 6, exits the stator
6 in a radial direction and is collected in an annular chamber 12 that surrounds the
stator 6. The housing 2 comprises a tangential outlet opening 13, which serves to
discharge the treated fluid.
[0033] As can be seen in Fig. 2 the impeller blades 11 of the rotor 7 are curved and extend
to the peripheral region or the rotor 7. On its periphery, the rotor 7 comprises a
plurality of teeth 15 that are arranged at equal circumferential distances from each
other, so that a chamber 16 is formed between each two subsequent teeth 15 in a row.
The teeth 15 are arranged along the entire circumference of the rotor 7. Further,
the teeth 15 are arranged in eight parallel, circular rows 14 of teeth. The rows 14
of teeth 15 are arranged parallelly and at the same radial distance from the rotation
axis 5. An annular cavity is formed between each two adjacent rows 14.
[0034] As best seen in Fig. 4, the stator 6 comprises a plurality of circular rows 17 of
radially inwardly protruding teeth 18, wherein the teeth 18 of each row 17 are arranged
at an equal circumferential distance to each other so that a chamber 19 is formed
between each two subsequent teeth 18 in a row 17. The teeth 18 of the stator 6 are
arranged to protrude into the annular cavity between two neighboring rows 14 of the
rotor 7. The teeth 15 of the rotor 7 and the teeth 18 of the stator 6, in a longitudinal
section as shown in Fig. 1, have a trapezoidal profile. The trapezoidal profile of
the teeth 15 of the rotor 7 tapers in a radially outward direction and the trapezoidal
profile of the teeth 18 of the stator 6 tapers in a radially inward direction. Specifically,
the profiles of the teeth 15 correspond to the profile of the annular cavity formed
between two adjacent rows 19 of the teeth 18 and the profiles of the teeth 18 correspond
to the profile of the annular cavity formed between two adjacent rows 14 of the teeth
15. However, the corresponding surfaces of the teeth and the annular cavity do not
glide on each other, but the surfaces facing each other define a gap between them
that allows fluid to flow therethrough.
[0035] In a first rotational position of the rotor 7 as shown in Fig. 2, the teeth 15 of
the rotor 7 and the teeth 18 of the stator 6 overlap each other, so that the respective
chambers 16 and 19 are aligned in an axial direction thereby forming channels extending
parallel to the rotation axis 5 of the rotor 7. Upon further rotation of the rotor
6, the chambers 16 of the rows 14 get gradually closed on their sides by the teeth
18 of the stator 6 and the chambers 19 of the rows 17 get gradually closed on their
sides by the teeth 15 of the rotor 7. Fig. 3 illustrates the beginning closing procedure,
wherein the teeth 15 of the rotor 7 have left their position, in which they are axially
aligned with the teeth 18 of the stator 6, and slightly project into the chambers
16,19.
[0036] The chambers 19 of the stator 6 each have a discharge opening 20 directed radially
outwardly. The discharge opening 20 is configured as a slit and has a circumferential
extent that corresponds to the circumferential distance between two teeth 18 in a
row 17. The discharge openings 20 each open into a discharge channel 21, that has
a cross section that widens in an outward direction. Specifically, the discharge channels
21 are defined between circumferential ribs 22 of the stator 6, wherein the ribs 21
taper in a radially outward direction.
[0037] In the embodiment shown in Fig. 1 to 5 the rows 14 of the rotor 7 and the rows 17
of the stator 6 have an equal number of teeth 15,18. In contrast, in the embodiment
shown in Fig 6, the rows 14 of the rotor 7 have one tooth 15 less than the rows 17
of the stator 6. Therefore, as illustrated in Fig. 6, the teeth 15 of the rotor 7
and the teeth 18 of the stator 6 do not overlap each other to the same extent.
[0038] The cavitation device 1 of the invention may be used in a system illustrated in Fig.
7. The system comprises a supporting frame 23, which carries a pump 24, a mixing tank
25, a power cabinet 26, a control console equipped with a touch screen 27 and an electric
engine 28. All components of the device are connected by a system of pipes 29. The
pipes 29 are equipped with temperature measuring devices 30, pressure measuring devices
31, a flow meter 32, a protective screen 33 for the operator and other devices necessary
for the measuring and defining the technical working parameters of the cavitational
pump.
[0039] The functioning of the device can be split into three cyclically changing phases,
whereby in the mechanical functioning of device, phase (I) is conjugated with phase
(III).
First phase (I)
[0040] The teeth 15 of the rotor 7 and the teeth 18 of the stator 6 are completely aligned
in an axial direction (as shown in Fig. 2). In this position of the rotor 7 relative
to the stator 6 axial channels are formed by the alignment of the chambers 16 and
19, through which the liquid moves. Further, in this position a gap is present between
the surfaces of the teeth 15 and the teeth 18 facing each other. In this gap there
is a sudden drop in pressure and caverns are formed.
[0041] During the movement of the liquid or gas-like environment, the pressure in the environment
drops. Thereby, the higher the movement speed of the environment, the lower the pressure.
Thus, when the liquid flows through the local narrowing (gaps), according to the continuity
equation of flows, there is an increase in speed with a simultaneous decrease in pressure
in this spot. At this point, absolute pressure reaches a value equal to the pressure
of saturated gases of the liquid at a given temperature; or it reaches a value equal
to the pressure at which dissolved gases are released from the liquid. In this case,
intensive steam formation (boiling) and release of gases is observed. The beginning
of the cavitational processes takes place, with the formation of caverns.
[0042] Characteristic of this phase is flow, accompanied by intensive mixing of liquid with
pulsation of speeds and pressure in the narrow gaps. Along with the main longitudinal
movement of liquid, a transversal movement and spinning motions of separate volumes
of liquid are observed.
Second phase (II)
[0043] The teeth 15 and the teeth 18 leave their axially aligned position, whereby the chambers
16,19 begin to get closed on their sides by the adjoining teeth, thereby slowing down
the movement of the liquid. Inside the closing chambers 16,19 there is a sudden spike
in pressure (direct hydraulic shock). In the process of hydrodynamic cavitation there
is a formation of fields of cavitational bubbles and cumulative micro streams with
a diameter of 5-200 micrometers, moving at speeds of 50-1500 m/s. When the liquid
moves in the chambers 16,19 the movement speed decreases, the pressure increases and
the cavitational bubbles implode. The pressure in the area of implosion of cavitational
bubbles can reach 1,5x10
3 MPa.
[0044] Liquid flow moves along the discharge channels 21 for the outlet of treated liquid.
The treated liquid is transferred from the discharge channels 21 into the annular
cavity 12 and to the outlet opening 13 of the device.
Third phase (III)
[0045] Under certain circumstances, when the liquid moves along the closed chambers 16,19
a phenomenon, associated with a change in the aggregate condition of the liquid occurs,
i.e. the transformation of the liquid into steam with the release of gases which were
dissolved in the liquid. Teeth rows 14 of the rotor 7 additionally provide flow of
liquid to the discharge channels 21 due to centrifugal forces. At low rotation speed
of the rotor 7 and at low pressure, no visible change in the liquid movement in the
discharge channels 21 is observed. When increasing the movement speed of the liquid
in the discharge channels 21 a second zone of cavitation formation arises, with the
formation of gas filled bubbles. A second area of local boiling is formed. i.e. the
formation of steam with the release of gas which is dissolved in the water. The subsequent
condensation and the implosion of caverns are accompanied by a hydraulic shock.
[0046] The speed at which the liquid moves in the device can be altered by the rotation
frequency of the rotor; pressure in the system can be altered, for example, by a stop
valve which is placed at the inlet 4. In this way a controlled cavitational process
is provided that safeguards the working organs from tear and wear. The productivity
of the device is directly dependent on altering these parameters and the parameters
of the processed liquid.
[0047] When treating liquid containing organic inclusions, in the axial channels, which
form when the chambers 16,19 are axially aligned, mechanical grinding, cross slicing,
mixing, and shredding occurs. This occurs due to the chopping movement of the rotor
teeth between the stator teeth, working on the principle of guillotine scissors.
[0048] The foregoing description and accompanying figures illustrate the principles, preferred
embodiments and modes of operation of the invention. However, the invention should
not be construed as being limited to the particular embodiments discussed above. Additional
variations of the embodiments discussed above will be appreciated by those skilled
in the art.
[0049] Therefore, the above-described embodiments should be regarded as illustrative rather
than restrictive. Accordingly, it should be appreciated that variations to those embodiments
can be made by those skilled in the art without departing from the scope of the invention
as defined by the following claims.
1. Cavitation device (1) comprising a rotor (7) arranged to rotate about a rotation axis
(5) and a stator (6), the rotor (7) and the stator each (6) comprising teeth (15,18)
arranged along a circle, the teeth (15) of the rotor (7) and the teeth (18) of the
stator (6) having cavitation surfaces facing each other and defining a gap between
them in order to induce cavitation in a liquid flowing therethrough, wherein the rotor
(7) comprises at least two circular rows (14) of radially outwardly protruding teeth
(15), the at least two circular rows (14) of the rotor (7) being arranged parallelly
having the same radius and arranged at an axial distance from each other so that an
annular cavity is formed between each two adjacent rows (14), wherein the stator (6)
comprises at least one circular row (17) of radially inwardly protruding teeth (18),
wherein the teeth (18) of each row (17) are arranged at a circumferential distance
to each other so that a chamber (19) is formed between each two subsequent teeth (18)
in a row (17), wherein the teeth (18) of the stator (6) are arranged to protrude into
the annular cavity between the at least two rows (14) of the rotor (7), so that the
chambers (16) of the at least two rows (14) of the rotor (7) and the chambers (19)
of the at least one stator (6), when axially aligned with each other, form channels
extending parallel to the rotation axis (5) of the rotor (7), characterized in that the chambers (19) of the stator (6) each have a discharge opening (20) directed radially
outwardly.
2. Device according to claim 2, wherein the stator (6) and the rotor (7) each comprise
a plurality of circular rows (14,17) of teeth (15,18), wherein the teeth (18) of the
rows (17) of the stator (6) protrude into the annular cavity between the rows (14)
of the rotor (7) and vice versa.
3. Device according to claim 1 or 2, wherein the teeth (15) of the rotor (7), in a longitudinal
section, have a profile that substantially corresponds to the profile of the annular
cavity of the stator (6), and vice versa.
4. Device according to claim 1, 2 or 3, wherein the cavitation surfaces of teeth (15,18)
of the rotor (7) and of the stator (6) facing each other are parallel to each other
and define a gap between them that has a width of 0,3-1,7 mm, preferably 0,4-0,6 mm.
5. Device according to claim 4, wherein adjustment means are provided for adjusting the
width of the gap.
6. Device according to any one of claims 1 to 5, wherein the teeth (15,18) of the rotor
(7) and of the stator (6), in a longitudinal section, have a trapezoidal or rectangular
profile.
7. Device according to any one of claims 1 to 6, wherein the rows (17) of the stator
(6) have the same number of teeth (18) and the rows (14) of the rotor (7) have the
same number of teeth (15).
8. Device according to any one of claims 1 to 7, wherein the rows (17) of teeth (18)
of the stator (6), in a cross section thereof, are congruent, and the rows (14) of
teeth (15) of the rotor (7), in a cross section thereof, are congruent.
9. Device according to any one of claims 1 to 8, wherein the rows (14) of teeth (15)
of the rotor (7) have the same number of teeth (18) as the rows (17) of the stator
(6).
10. Device according to any one of claims 1 to 8, wherein the at least two rows (14) of
teeth (15) of the rotor (17) each have fewer teeth (15), in particular one tooth less,
than the at least one row (17) of teeth (18) of the stator (7) .
11. Device according to any one of claims 1 to 10, wherein the discharge opening (20)
opens into a discharge channel (21), that has a cross section that preferably widens
in an outward direction.
12. Device according to any one of claims 1 to 11, wherein the ratio of the circumferential
extent of each tooth (15, 18) to the circumferential extent of each chamber (16, 19)
is 0,6-1,15.
13. Device according to any one of claims 1 to 12, wherein the stator (6) encloses a circular
cavity, in which the rotor (7) is arranged in a rotatable manner and which comprises
a central inlet arranged coaxially with the rotation axis (5) of the rotor (7).
14. Device according to any one of claims 1 to 13, wherein the rotor (7) comprises impeller
blades (11) to direct fluid that enters the cavity through the inlet radially outwardly
to the chambers (16,19) of the rotor (7) and the stator (6).
1. Kavitationsvorrichtung (1), umfassend einen Rotor (7), der zum Drehen um eine Drehachse
(5) angeordnet ist, und einen Stator (6), wobei der Rotor (7) und der Stator (6) jeweils
Zähne (15, 18) umfassen, die entlang eines Kreises angeordnet sind, wobei die Zähne
(15) des Rotors (7) und die Zähne (18) des Stators (6) Kavitationsflächen aufweisen,
die einander zugekehrt sind und einen Spalt dazwischen definieren, um Kavitation in
eine Flüssigkeit einzuleiten, die dort hindurch strömt, wobei der Rotor (7) zumindest
zwei kreisförmige Reihen (14) von radial nach außen vorstehenden Zähnen (15) umfasst,
wobei die zumindest zwei Reihen (14) des Rotors (7) parallel mit demselben Radius
angeordnet sind und mit einem axialen Abstand voneinander angeordnet sind, sodass
ein ringförmiger Hohlraum zwischen jeweils zwei benachbarten Reihen (14) ausgebildet
ist, wobei der Stator (6) zumindest eine kreisförmige Reihe (17) von radial nach innen
vorstehenden Zähnen (18) umfasst, wobei die Zähne (18) jeder Reihe (17) in einem umfänglichen
Abstand zueinander angeordnet sind, sodass eine Kammer (19) zwischen jeweils zwei
aufeinanderfolgenden Zähnen (18) in einer Reihe (17) ausgebildet ist, wobei die Zähne
(18) des Stators (6) zum Vorstehen in den ringförmigen Hohlraum zwischen den zumindest
zwei Reihen (14) des Rotors (7) angeordnet sind, sodass die Kammern (16) der zumindest
zwei Reihen (14) des Rotors (7) und die Kammern (19) des zumindest einen Stators (6),
wenn sie axial aneinander ausgerichtet sind, Kanäle ausbilden, die parallel zur Drehachse
(5) des Rotors (7) verlaufen, dadurch gekennzeichnet, dass
die Kammern (19) des Stators (6) jeweils eine Ablassöffnung (20) aufweisen, die radial
nach außen gerichtet ist.
2. Vorrichtung nach Anspruch 2, wobei der Stator (6) und der Rotor (7) jeweils mehrere
kreisförmige Reihen (14, 17) von Zähnen (15, 18) umfassen, wobei die Zähne (18) der
Reihen (17) des Stators (6) in den ringförmigen Hohlraum zwischen den Reihen (14)
des Rotors (7) vorstehen und umgekehrt.
3. Vorrichtung nach einem der Ansprüche 1 oder 2, wobei die Zähne (15) des Rotors (7)
in einem Längsschnitt ein Profil aufweisen, das im Wesentlichen dem Profil des ringförmigen
Hohlraums des Stators (6) entspricht und umgekehrt.
4. Vorrichtung nach einem der Ansprüche 1, 2 oder 3, wobei die Kavitationsflächen von
Zähnen (15, 18) des Rotors (7) und des Stators (6), die einander zugekehrt sind, parallel
zueinander sind und einen Spalt dazwischen definieren, der eine Breite von 0,3 bis
1,7 mm, vorzugsweise 0,4 bis 0,6 mm, aufweist.
5. Vorrichtung nach Anspruch 4, wobei Einstellmittel zum Einstellen der Breite des Spalts
vorgesehen sind.
6. Vorrichtung nach einem der Ansprüche 1 bis 5, wobei die Zähne (15, 18) des Rotors
(7) und des Stators (6) in einem Längsschnitt ein trapezförmiges oder rechteckiges
Profil aufweisen.
7. Vorrichtung nach einem der Ansprüche 1 bis 6, wobei die Reihen (17) des Stators (6)
dieselbe Anzahl von Zähnen (18) aufweisen und die Reihen (14) des Rotors (7) dieselbe
Anzahl von Zähnen (15) aufweisen.
8. Vorrichtung nach einem der Ansprüche 1 bis 7, wobei die Reihen (17) von Zähnen (18)
des Stators (6) in einem Querschnitt davon kongruent sind und die Reihen (14) von
Zähnen (15) des Rotors (7) in einem Querschnitt davon kongruent sind.
9. Vorrichtung nach einem der Ansprüche 1 bis 8, wobei die Reihen (14) von Zähnen (15)
des Rotors (7) dieselbe Anzahl von Zähnen (18) wie die Reihen (17) des Stators (6)
aufweisen.
10. Vorrichtung nach einem der Ansprüche 1 bis 8, wobei die zumindest zwei Reihen (14)
von Zähnen (15) des Rotors (7) jeweils weniger Zähne (15), insbesondere einen Zahn
weniger, als die zumindest eine Reihe (17) von Zähnen (18) des Stators (7) aufweisen.
11. Vorrichtung nach einem der Ansprüche 1 bis 10, wobei die Ablassöffnung (20) in einen
Ablasskanal (21) mündet, der einen Querschnitt aufweist, welcher sich vorzugsweise
in einer Richtung nach außen aufweitet.
12. Vorrichtung nach einem der Ansprüche 1 bis 11, wobei das Verhältnis der umfänglichen
Ausdehnung jeden Zahns (15, 18) zur umfänglichen Ausdehnung jeder Kammer (16, 19)
0,6 bis 1, 15 beträgt.
13. Vorrichtung nach einem der Ansprüche 1 bis 12, wobei der Stator (6) einen kreisförmigen
Hohlraum einschließt, in dem der Rotor (7) drehbar angeordnet ist, und der einen mittigen
Einlass umfasst, welcher koaxial mit der Drehachse (5) des Rotors (7) angeordnet ist.
14. Vorrichtung nach einem der Ansprüche 1 bis 13, wobei der Rotor (7) Laufradschaufeln
(11) zum Leiten von Fluid, das durch den Einlass in den Hohlraum eintritt, radial
nach außen zu den Kammern (16, 19) des Rotors (7) und des Stators (6) umfasst.
1. Dispositif de cavitation (1) comprenant un rotor (7) agencé pour tourner autour d'un
axe de rotation (5) et un stator (6), le rotor (7) et le stator (6) comprenant chacun
des dents (15, 18) agencées le long d'un cercle, les dents (15) du rotor (7) et les
dents (18) du stator (6) ayant des surfaces de cavitation en regard l'une de l'autre
et définissant un espacement entre elles afin d'induire une cavitation dans un liquide
qui les traverse, dans lequel le rotor (7) comprend au moins deux rangées circulaires
(14) de dents (15) faisant saillie radialement vers l'extérieur, les au moins deux
rangées circulaires (14) du rotor (7) étant agencées parallèlement avec le même rayon
et étant agencées à une distance axiale l'une de l'autre de sorte qu'une cavité annulaire
soit formée entre chacune de deux rangées adjacentes (14), dans lequel le stator (6)
comprend au moins une rangée circulaire (17) de dents (18) faisant saillie radialement
vers l'intérieur, dans lequel les dents (18) de chaque rangée (17) sont agencées à
une distance circonférentielle l'une de l'autre de sorte qu'une chambre (19) soit
formée entre chacune de deux dents postérieures (18) d'une rangée (17), dans lequel
les dents (18) du stator (6) sont agencées pour faire saillie dans la cavité annulaire
entre les au moins deux rangées (14) du rotor (7) de sorte que les chambres (16) des
au moins deux rangées (14) du rotor (7) et les chambres (19) du au moins un stator
(6), lorsqu'elles sont alignées axialement l'une avec l'autre, forment des canaux
s'étendant parallèlement à l'axe de rotation (5) du rotor (7), caractérisé en ce que les chambres (19) du stator (6) ont chacune une ouverture de décharge (20) dirigée
radialement vers l'extérieur.
2. Dispositif selon la revendication 2, dans lequel le stator (6) et le rotor (7) comprennent
chacun une pluralité de rangées circulaires (14, 17) de dents (15, 18), dans lequel
les dents (18) des rangées (17) du stator (6) font saillie dans la cavité annulaire
entre les rangées (14) du rotor (7) et vice-versa.
3. Dispositif selon la revendication 1 ou 2, dans lequel les dents (15) du rotor (7)
ont, en coupe longitudinale, un profil qui correspond sensiblement au profil de la
cavité annulaire du stator (6) et vice-versa.
4. Dispositif selon la revendication 1, 2 ou 3, dans lequel les surfaces de cavitation
des dents (15, 18) du rotor (7) et du stator (6) en regard l'une de l'autre sont parallèles
l'une à l'autre et définissent un espacement entre elles qui a une largeur de 0,3
à 1,7 mm, de préférence de 0,4 à 0,6 mm.
5. Dispositif selon la revendication 4, dans lequel des moyens d'ajustement sont prévus
pour ajuster la largeur de l'espacement.
6. Dispositif selon l'une quelconque des revendications 1 à 5, dans lequel les dents
(15, 18) du rotor (7) et du stator (6) ont, en coupe longitudinale, un profil trapézoïdal
ou rectangulaire.
7. Dispositif selon l'une quelconque des revendications 1 à 6, dans lequel les rangées
(17) du stator (6) ont le même nombre de dents (18) et les rangées (14) du rotor (7)
ont le même nombre de dents (15).
8. Dispositif selon l'une quelconque des revendications 1 à 7, dans lequel les rangées
(17) de dents (18) du stator (6) sont, en coupe transversale, congruentes et les rangées
(14) de dents (15) du rotor (7) sont, en coupe transversale, congruentes.
9. Dispositif selon l'une quelconque des revendications 1 à 8, dans lequel les rangées
(14) de dents (15) du rotor (7) ont le même nombre de dents (18) que les rangées (17)
du stator (6).
10. Dispositif selon l'une quelconque des revendications 1 à 8, dans lequel les au moins
deux rangées (14) de dents (15) du rotor (7) ont chacune moins de dents (15), en particulier
une dent en moins, que la au moins une rangée (17) de dents (18) du stator (7).
11. Dispositif selon l'une quelconque des revendications 1 à 10, dans lequel l'ouverture
de décharge (20) débouche dans un canal de décharge (21) qui a une section transversale
qui s'élargit de préférence en direction de l'extérieur.
12. Dispositif selon l'une quelconque des revendications 1 à 11, dans lequel le rapport
de l'extension circonférentielle de chaque dent (15, 18) à l'extension circonférentielle
de chaque chambre (16, 19) est de 0,6 à 1,15.
13. Dispositif selon l'une quelconque des revendications 1 à 12, dans lequel le stator
(6) enserre une cavité circulaire, dans laquelle le rotor (7) est agencé de manière
à pouvoir tourner et qui comprend une entrée centrale agencée coaxialement avec l'axe
de rotation (5) du rotor (7).
14. Dispositif selon l'une quelconque des revendications 1 à 13, dans lequel le rotor
(7) comprend des pales d'hélice (11) pour diriger un fluide qui entre dans la cavité
à travers l'entrée radialement vers l'extérieur en direction des chambres (16, 19)
du rotor (7) et du stator (6).