Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND SYSTEM FOR PUMPING A LIQUID CONTAINING PARTICLES;
PREFERABLY FISH IN WATER
Technical Field of the Invention
The present invention relates to a system for pumping a liquid containing
particles or solid substances, where the particles or solid substances is not
intended
to be pumped through the liquid pump used for the pumping operation, avoiding
exposing said particles or solid substances for moveable parts of the pumps or
exposing the same for high liquid velocities. In particular, but not
exclusively, the
system is suitable for pumping fish in water, in particular, but not
exclusively living
fish. The particles may also other type of food.
In particular, the invention relates a method and system for pumping particles
contained in a liquid, preferably living fish in water but not exclusively,
from a liquid
volume containing the particles to a receiving unit through associated one or
more
closed pipelines, using at least one pump; where liquid and particles are
drawn
through a pipeline from the liquid volume to a chamber for establishing a sub-
pressure in the chamber by means of one or more pumps; and where liquid and
particles are transported from the chamber through one or more closed ducts or
pipelines to a receiving unit contained in a liquid, preferably living fish in
water.
Background for the invention
When pumping fish there is a need for a system enabling pumping of a
continuous flow of water from the suction side of the pump, pumping water and
fish
for delivery of water and fish at a higher level, and at the same time
obtaining a large
total lifting height and proper and adequate lifting capacity on the suction
side
without exposing the fish for excessive water velocities as in an ejector
pumping
system. Moreover, the system must be able to be positioned above the water for
example in a temporary fishing cage containing fish for transfer or the water
in a well
boat for transporting for example fish to a abbatoir, the only part of the
pumping
system being submerged just below the water level being an inlet funnel for
suction
of water.
There exit many prior art solutions for pumping fish, but all of them differ
from
the present invention in that they cannot combine functions as being arranged
above
water; large total lifting height, appropriate proper lifting height on the
suction side;
and continuous water flow from inlet to outlet without exposing the fish for
large and
detrimental water velocities or movable pumping parts, also when pumping large
fish.
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US 4,551,042 discloses a pump for pumping fish where water is extracted and
air is added at a location in the pumping system higher than the initial air
injection
point, thereby excluding a certain percentage of water, whereupon the
efficiency is
not only increased, but variable control capabilities are achieved. According
to this
solution, the fish is lifted up via a transport pipe to a chamber by means of
formation
of a sub-pressure in the transport pipeline, the pump comprises a pump for
gas/air
and pumps for liquid/water, where air and water is injected at a pressure
through
openings into the lower part of the pipe. Air is also injected in an upper air
supply
ring, such that the fish is transported up in party air born state through the
transport
pipe to a height above water level.
Another prior art method for pumping fish is described on EP 0352941, the
method comprising use of a fish pumping device where a chamber receives a
mixture og water and fish via an inlet orifice when the chamber is subjected
to an
under-pressure, and where the mixture of water and fish is transported out of
the
chamber along to the outlet, when the chamber becomes subjected to an over-
pressure.
Other known prior art methods are disclosed in the following listed patents or
patent application: EP 1179508; WO 2010/082834; US 9,011,680 B; GB 2 498 667
B; NO 394301 B; NO 394302 B; NO 303841 B; and US 4,551,042 B.
Summary of the Invention
An object of the present invention is to provide a device for pumping liquid
and
particles, preferably water and fish, where liquid and particles float
continuously in a
pipeline from inlet to outlet, without moving the particles through a liquid
pump with
moveable parts.
Another object of the invention is to provide a device for pumping a liquid
and
particles, preferably water and fish, where the velocity of the liquid flow
may be
maintained at a velocity that does not cause any damage to the particles.
A further object of the invention is to provide a device for pumping liquid
and
particles, preferably water and fish, where the suction side has sufficient
lifting height
so that the pumping device may be positioned at a certain height above the
water
surface, for example onboard a well boat or a fishing vessel, and at the same
time
permitting that the inlet end for liquid and particles to be positioned just
below the
water surface.
Yet another object of the invention is to provide a device for pumping liquid
and particles, preferably water and fish, requiring as small space or foot
print and still
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providing sufficient lifting height to transport liquid and particles to a
plant positioned
a distance apart or at a large height above the water surface.
Another object of the invention is to provide a device for pumping a liquid
and
particles, preferably water and fish, with sufficient capacity so that the
water flow
obtains a velocity sufficient to catch living fish without allowing the fish
to
unintentionally escape or swim away from the suction inlet, also when using
pipes
with large pipe diameter, thus allowing pumping of large fish.
According to the invention, the objects are achieved by a solution more
clearly
defined by the independent claim, while embodiments, variants and alternatives
are
defined by the dependent claims.
According to a first embodiment of the invention, it is provided a method for
pumping particles contained in a liquid, preferably living fish in water, from
a liquid
volume containing the particles to a receiving unit through associated one or
more
closed pipelines, using at least one pump; where liquid and particles are
drawn
through a pipeline from the liquid volume to a chamber for by establishing a
sub-
pressure in the chamber by means of one or more pumps; and where liquid and
particles are transported from the chamber through one or more closed ducts to
a
receiving unit. The liquid and particles are delivered from the chamber into
an ejector
and from the ejector to the receiving unit through a pipeline by means of a
pump
pumping water through the ejector and into duct for formation of a sub-
pressure at
the ejector and for providing a required liquid flow through the duct, and by
connecting the suction side of the pump to a separate chamber connected to the
chamber via an outlet with openings that are smaller than the particles for
supply of
only liquid and gas from the chamber into the chamber, the ejector and the
pump
together forming a sufficient sub-pressure with a subsequent over-pressure so
that
sufficient volume of liquid and particles may be drawn from the liquid volume
through
the closed duct to the chamber, and from the chamber through the ejector and
the
duct to the receiving unit, preventing the particles from passing through the
pump.
One or more compressors may be used for supply of pressurized gas
delivered to a distribution chamber, allowing the gas to ascend upwards in the
liquid
via openings in the chamber wall, drawing particles through the chamber past
the
outlet and into the ejector.
Moreover, the pump may pump gas in addition to liquid, so that the pump
evacuates gas from the chamber and the volume that is substituted by liquid.
drawn
up from the liquid volume.
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According to one embodiment, a rotating sieve or band sieve may be used in
association with the outlet to the chamber in order to transport the particles
past the
inlet towards the ejector.
The sieve may preferably be cleaned by a liquid jet forcing liquid in
direction
from the chamber into the chamber in order to force particles away from the
outlet
and into the ejector.
According to an alternative, nozzles forming a part of the ejector may be
used,
allowing a part of the flow of liquid out of the ejector to pass through the
outlet for
forcing particles away from the outlet and into the ejector.
According to another embodiment, the particles may be shielded from the
liquid flow out of the ejector by means of a sieve or filter at least until
the liquid
velocity out of the ejector has dropped downstream of the ejector to a level
where
said flow does not harm the particles.
According to the invention, it is also provided a system for pumping particles
contained in a liquid, preferably living fish in water, comprising a pump; a
suction line
arranged between the pump and a liquid volume containing the liquid and the
particles to pumped; a receiving unit, and a pipeline for transferring the
pumped
liquid and particles. An ejector is arranged downstream of the pump, an inlet
of
which being arranged in fluid communication with an outlet of the pump and
with a
device for formation of a sub-pressure at inlet of the ejector, providing a
required
liquid flow through the duct, said device being a separate chamber in fluid
communication with chamber via an outlet with openings that are smaller than
the
particles for supply of only liquid and gas from the chamber into the chamber,
enabling both the ejector and the pump together to form a sufficient sub-
pressure
with a subsequent over-pressure at the outlet of the ejector so that
sufficient volume
of liquid and particles may be drawn from the liquid volume through the closed
duct
to the chamber, and from the chamber through the ejector and the duct to the
receiving unit, preventing the particles from passing through the pump.
According to one embodiment of the system, the suction side of the pump
may be connected to the chamber at the bottom of the chamber, and that outlet
is
positioned at the upper end of the chamber, so that gas mixed with the liquid
will
ascend upwards and back into the chamber through the outlet, while liquid is
drawn
downwards in the chamber and into the pump. The suction side of the pump may
also be connected to an external supply of liquid.
The suction side may be connected to both the chamber and an external
supply, where the connection may be completely opened and closed by means of a
valve on the supply line and a valve on the connection to the chamber, said
valves
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preferably being controlled so that it is a least flow resistance in the
connection line
to the chamber, until the outlet becomes partly or completely clogged by
particles,
and then it will be lower flow resistance in the external supply until gas
delivered by
the compressor draws away said particles when the gas ascends upwards through
5 the liquid column in the chamber.
An outlet is arranged at the top of the chamber, having a controllable opening
for gas with a non-return valve or check valve, configured to close at a sub-
pressure
in the chamber, and in case of build up of gas with overpressure at the top of
the
chamber the gas will force it way out of the chamber through the outlet, and
by
controlling or adjusting the opening of the outlet, sufficient overpressure
will be
maintained at the top of the chamber to force or press liquid and particles to
the
receiving unit.
The gas pressed out through the outlet may be directed to the distribution
chamber for supply of additional gas at the bottom of the chamber. The outlet
(9)
may be provided with a third line with adjustable or controllable opening and
a valve
for allowing superfluous gas to escape out of the system, and wherein the
valve may
be mechanically adjusted or controlled for opening at a certain pressure,
controlled
manually or automatically by a sensor measuring the pressure or liquid level
inside
the chamber.
The compressor may be provided with two outlets, each with a valve where
one of the valves being associated with the distribution chamber and the other
with
the ejector, so that by closing valve on the outlet from the distribution
chamber and
supplying pressurized gas from the compressor into the ejector, a sub-pressure
is
formed at the ejector, emptying the closed duct, the chamber and the chamber
for
gas, said gas being substituted by liquid drawn up from the liquid volume.
A non-return valve or check valve may be arranged in the closed duct or duct,
closing if the flow of liquid and particles is moving in wrong direction from
the duct to
the liquid volume, and opens when the liquid flow moves in opposite direction.
According to another embodiment of the invention, it is provided a system for
pumping particles contained in a liquid, preferably living fish in water. The
system
comprises a liquid volume containing the particles; one or more closed ducts
from
the liquid volume to a chamber for receipt of liquid and particles by
establishing a
sub-pressure in the chamber; one or more pumps for supply of gas and liquid;
one or
more compressors for supply of pressurized gas; and one or more closed ducts
for
transport of liquid and particles from the chamber to a receiving unit.
The chamber is provided with an outlet for liquid and particles into an
ejector
and from the ejector to a closed duct ending at the receiving unit; and a
distribution
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chamber into which pressurized gas is supplied from the compressor(s), the gas
ascending upwards in the liquid via openings in the chamber wall; and a pump
pumping
water through the ejector and into duct for formation of a sub-pressure at the
ejector and
for providing a required liquid flow through the duct, the suction side of the
pump being
connected to the chamber so that the volume of liquid supplied to the pump is
drawn
from the liquid volume; the chamber being connected to the chamber via an
outlet with
openings that are smaller than the particles for supply of only liquid and gas
from the
chamber into the chamber, so that the gas ascend vertically in the chamber,
the ejector
and the pump together forming a sufficient sub-pressure with a subsequent over-
pressure so that sufficient volume of liquid and particles may be drawn from
the liquid
volume through the closed duct to the chamber, and from the chamber through
the
ejector and the duct to the receiving unit, preventing the particles from
passing through
the pump.
According to one embodiment, the pump may pump gas in addition to liquid, so
that the pump evacuates gas from the chamber and the chamber that is
substituted by
liquid drawn up from the liquid volume.
According to an embodiment, there is provided a method for pumping particles
contained in a liquid, preferably living fish in water, from a liquid volume
containing the
particles to a receiving unit through one or more associated closed pipelines,
using at least
one pump; where liquid and particles are drawn through a first pipeline from
the liquid
volume to a chamber for by establishing a sub-pressure in the chamber by means
of the at
least one pump; and where liquid and particles are transported from the
chamber through
one or more second closed pipelines to a receiving unit, wherein the liquid
and particles
are delivered from the chamber into an ejector and from the ejector to the
receiving unit
through the one or more second closed pipeline by means of the at least one
pump
pumping water through the ejector and into duct for formation of a sub-
pressure at the
ejector and for providing a required liquid flow through the one or more
second closed
pipelines duct, and by connecting the suction side of the at least one pump to
a separate
chamber connected to the chamber via an outlet with openings that are smaller
than the
particles for supply of only liquid and gas from the chamber into the chamber,
the ejector
and the at least one pump together forming a sufficient sub-pressure with a
subsequent
over-pressure so that sufficient volume of liquid and particles may be drawn
from the liquid
volume through the first closed pipelines to the chamber, and from the chamber
through
the ejector and the one or more second closed pipelines to the receiving unit,
preventing
the particles from passing through the at least one pump.
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According to another embodiment, there is provided a system for pumping
particles contained in a liquid, preferably living fish in water, comprising a
pump; a suction
line arranged between the pump and a liquid volume containing the liquid and
the particles
to pumped; a receiving unit, and a pipeline for transferring the pumped liquid
and particles,
wherein an ejector arranged downstream of the pump, an inlet of which being
arranged in
fluid communication with an outlet of the pump and with a device for formation
of a sub-
pressure at inlet of the ejector, providing a required liquid flow through the
pipeline, said
device being a separate chamber in fluid communication with chamber via an
outlet with
openings that are smaller than the particles for supply of only liquid and gas
from the
chamber into the separate chamber, enabling both the ejector and the pump
together to
form a sufficient sub-pressure with a subsequent over-pressure at the outlet
of the ejector
so that sufficient volume of liquid and particles may be drawn from the liquid
volume
through the closed pipeline to the chamber, and from the chamber through the
ejector and
the pipeline to the receiving unit, preventing the particles from passing
through the pump.
Short Description of the Drawings
An exemplary embodiment of the invention shall in the following be described
in
further detail, referring to the accompanying drawings, wherein:
Figure 1 shows schematically, partly in vertical section, an outline of an
exemplary
embodiment of the invention for pumping fish from a cage to a well onboard a
well boat;
Figure 2 shows schematically in an enlarge scale a vertical section through an
exemplary embodiment of a pump according to the present invention;
Figure 3 shows schematically, partly in vertical section, an outline of a
second
exemplary embodiment according to the invention for pumping fish from a cage
to a well
onboard a well boat;
Figure 4 shows schematically in an enlarge scale a vertical section through a
second exemplary embodiment of a pump according to the invention;
Figure 5 shows schematically, partly in vertical section, through a third
exemplary
embodiment of a pump according to the present invention; and
Figure 6 to 8 show schematically an outline of a second exemplary embodiment
of
a pump according to the invention.
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Detailed Description of the Exemplary Embodiment disclosed in the Drawings
The following description of the exemplary embodiment refers to the
accompanying drawings. The same reference numbers in different drawings
identify
the same or similar elements. The following detailed description does not
limit the
invention. Instead, the scope of the invention is defined by the appended
claims. The
following embodiments are discussed, for simplicity, with regard to various
forms of
pumping systems and pumps used for pumping water and fish. It should be
appreciated, however, that the referenced pumping system may also be used for
pumping other mixtures of a liquid and a substance, or particles or soft or
solid
bodies without deviating from the inventive idea.
Reference throughout the specification to "one embodiment" or "an
embodiment" means that a particular feature, structure, or characteristic
described in
connection with an embodiment is included in at least one embodiment of the
subject
matter disclosed. Thus, the appearance of the phrases "in one embodiment" or
"in
an embodiment" in various places throughout the specification is not
necessarily
referring to the same embodiment.
Moreover, the arrows in the drawings indicate the direction of flow and
movement through the system and the direction of rotation with respect to
direction
of flow.
Figure 1 shows schematically, partly in vertical section, an outline of a
first
exemplary embodiment of the invention for pumping fish from a cage to a well
onboard a well boat, while Figure 2 shows schematically in an enlarge scale a
vertical section through an exemplary embodiment of a pump according to the
present invention. As indicated in the Figures, water and fish 2 (particles)
is pumped
up from a well 1 in the direction of the arrows and delivered to a tank or
container or
the like 16.
As indicated in Figure 1 and 2, the pumping plant comprises a hose with a
suction funnel 3, where the end of the hose provided with the funnel 3 is
submerged
into the upper layer 20 of a liquid volume 1 containing the fish 2. The
opposite end of
the hose with the funnel 3 is connected to a first chamber 4. In association
with the
first chamber 4 a distribution chamber 11 is arranged, the interface plate
between
the first chamber 4 and the distribution chamber 11 being provided with a
number of
small holes or apertures for supply of air or a gas in the form of small
bobbles to the
chamber 4. This distribution chamber 11 is connected to a compressor 12,
delivering
pressurized gas to the distribution chamber 11 and hence to the firs chamber 4
through the small openings or apertures. The first chamber 4 extends
vertically
upwards to an outlet with a non-return valve or check valve 14, where liquid
and
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particles 2 pass through the valve 14 and into an ejector 7 and then further
into a
pipeline 15, extending from the outlet of the ejector 7 and to a well, tank or
a
container 16. The check valve 14 opens up when the pressure in the first
chamber 4
is larger than the pressure in the ejector 7 and closes when the pressure in
the first
chamber 4 is lower than the pressure in the ejector 7. The check valve 14
prevents
in this manner liquid and particles from returning back from the pipeline 15
and
downwards into the liquid volume 1.
On top of the first chamber 4, an outlet 9 is provided, the outlet 9 being
provided with an associated valve 10 for evacuating air trapped at the top of
the first
chamber 4, while at the same time the valve 10 closes when an under-pressure
is
formed in the first chamber 4, preventing that false air is drawn into the
first chamber
4. If possible the outlet 9 is connected to a point on the pipeline 15 where
the
pipeline ascend upwards toward the outlet, allowing air to be drawn with the
liquid
flow and out of the pipeline 15, into the tank 16.
In the upper part of the first chamber 4, a liquid outlet 6 is provided for
transfer
of liquid to an outer chamber 5, the outlet 6 having openings or apertures
that is
smaller tan the smallest particles 2 to be pumped, thus preventing said
smallest
particles to enter into the outer chamber 5.
The outer chamber 5 is given such height that air that is drawn with the water
into the outer chamber 5 ascends up and back into the first chamber 4 through
the
outlet 6, at the same time as the liquid is drawn downwards and into the pump
13. In
this manner the suction side of the pump 13 contributes to filling of liquid
in the first
chamber 4, and during operation, to parts of the flow of liquid and particles
2 in the
first chamber 4.
The pump 13 is a liquid pump of desired type, such as a positive pressure
pump or a centrifugal pump with a non-return valve or check valve, where the
pump
13 sealed when it is not in operation, such that the liquid does not flow back
or return
through the pump 13 and back into the first chamber 4.
The liquid is pumped through the pump 13 and into the ejector chamber 8 and
further through the ejector 7 and into the pipeline 15. When the first chamber
4 is to
be filled with liquid, there is no liquid in the pump 13 or in the ejector 7.
It will then be
the lowest pressure in the first chamber 4. The non-return valve or check
valve 14
will the be closed, such that the pump 13 will form a sufficient sub-pressure
in the
first chamber 4 in order to lift liquid and particles 2 up from the liquid
volume 1
through the hose with suction funnel 3. When the liquid level has come up to
the
pump 13, then the compressor 12 may be started. The compressor 12 forces the
air
into the distribution chamber 11, so that air is supplied to the bottom of the
first
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chamber 4. When this air ascends, it will function as a mammoth pump where the
ascending air sucks or draws water up through the chamber 4.
Simultaneously the pump 13 pumps liquid into the antechamber 8 and from
the antechamber 8 through the ejector 7, such that the ejector 7 forms an
further
pressure drop in the pipeline 15 at the ejector 7, and a corresponding
pressure
increase in the pipeline downstream of the ejector 7. In this manner both the
pump
13, the mammoth pump and the ejector 7 contribute to a liquid flow of 200 to
300
liters per second and a lifting height in the order of 15 to 20 meters, in
spite of the
first chamber 4 having a limited height of 2.5 meters, and without causing any
increase in liquid velocity in the ejector 7 that may cause damage or injury
to the
particles 2.
At the exit of the pipeline 15, the flow of liquid and particles 2 is led into
a
receiving unit 16, where the particles 2 are transported for further storage
or
processing.
Figure 3 shows schematically, partly in vertical section, an outline of a
second
exemplary embodiment according to the invention for pumping fish from a cage
to a
well onboard a well boat, while Figure 4 shows schematically in an enlarge
scale a
vertical section through a second exemplary embodiment of a pump according to
the
invention. . As indicated in the Figure, water and fish 2 (particles) is
pumped up from
a well 1 in the direction of the arrows and delivered to a tank or container
or the like
16.
Figure 3 and 4 disclose an alternative embodiment of the invention n. This
alternative embodiment differs from the embodiment disclosed in Figures 1 and
2, in
that the pump 13 is connected to an external liquid supply 19 in addition to
the
connection to the outer chamber 5. The supply of liquid is controlled by means
of a
valve 17 on the external supply line 19 and a valve 18 on the supply from the
chamber 5.
The external supply 19 is used for example for cleaning of the system with
pure or clean water, filling of water at start-up and operation of the ejector
7 in those
cases where particles 2 may have a tendency to clog the outlet 6.
When the external supply 19 is connected to the liquid volume 1, the system
may be operated with a valve 17 partly open and the valve 18 completely open.
The
pump 13 will then draw liquid supply with lowest flow resistance, so that if
the outlet
6 becomes more or less clogged, then the least flow resistance will be in in
the
external supply 9. When the flow of air and liquid then flowing in the chamber
4 has
cleaned the outlet 6, the pump 13 will again draw water from the external
chamber 5,
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since the valve only will be partly open and function as a flow resistance in
the
external supply 19.
Figure 5 shows schematically, partly in vertical section, through a third
exemplary embodiment of a pump according to the present invention. The Figure
5 shows yet another exemplary embodiment that differs from the previously
described
embodiments in that fluid out of the outlet 9 is fed to the distribution
chamber 11 for
increase of air supply to the bottom of the first chamber 4. The outlet 9 is
in addition
connected to a valve 21 that may open a third line for addition of free air
when the air
at the top of the first chamber 4 obtains a certain increase in pressure or
when a
10 certain liquid level is obtained. The valve 21 may be controlled so as
to open at a
certain over-pressure. This occur when a larger build-up of air at the top of
the first
chamber 4 is formed, said air then obtaining an increase in pressure when the
passage for the liquid below the pocket of air is narrowing in and the liquid
is forced
against the pocket of air.
Figure 5 shows also a further embodiment, where the gas from the
compressor 12 is directed either to the distribution chamber 11 or to the
ejector 7.
This is obtained by providing the compressor 12 with first line to the
distribution
chamber 11 that may be closed and open by a valve 22 and a second line 24
communicating with the ejector 7, that may be closed and opened by a valve 23.
The
valves 22,23 may be controlled manually or by a sensor sensing the liquid
height in
the chamber 4.
This function is used when the system is in progress of filling liquid. In
such
case the valve 22 is closed and the valve 23 is opened, while the compressor
delivers pressurized gas into the ejector 7, creating a sub-pressure
evacuating gas
from the first chamber 4 and sucking up liquid from the liquid volume 1 and
into the
first chamber 4.
Figure 6 to 8 show schematically an outline of a second exemplary
embodiment of a pump according to the invention. This second exemplary
embodiment differs from the first exemplary embodiment in that the outlet 6
for liquid
to an outer chamber 5 is configured as a rotating sieve (ref. Figure 6) or a
rotating
bans sieve (ref. Figure 7), powered by a separate motor 28.
At the inlet to the ejector 7, a flushing unit 25 is arranged, forcing water
through an outlet 6 from the side facing the chamber 5 and into the chamber 4.
A
closed wall 26 guides the particles and the liquid flow delivered from the
flushing unit
25 into the ejector 7. The particles that follow the outlet when rotating, is
drawn to the
flushing unit 25 where the particles 2 are forced away from the outlet 6 by
the liquid
flow from the flushing unit25 and in such manner is fed to the inlet of the
ejector 7.
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When the liquid has passed through the outlet 6, the liquid is pumped through
the
pump 13 and onto the antechamber 8 and from the antechamber into the ejector
7.
A sieve 27 shields the particles 2 from the strong and hard water flow coming
out of the ejector 7 until the particles 2 and the water flow out of the
ejector 7 are
mixed in the pipeline 15 so far downstream of the ejector 7 that the water
velocity out
of the ejector 7 has been reduced to a level that does not cause any harm or
damage to the particles 2.
According to one embodiment, the compressor 12 forces air into the distri-
bution chamber 11, such that air is introduced into the chamber 4. The air is
mainly
supplied for moving the particles away from the outlet and into the ejector 7.
It is of
importance that the system is configured in such that sufficient sub-pressure
is
established at the inlet to the ejector 7. Moreover, it is also important that
the
chamber is formed and configured in such way that the air ascends upwards in
the
chamber 4, ending at the inlet to the ejector 7. If the ejector 7 creates an
increased
sub-pressure 4, the ejector 7 will contribute to increased flow of liquid and
particles 2
into the chamber 4. A part of the liquid flow will pass through the pump 13,
while the
remaining part of the liquid flow will enter at the suction side of the
ejector 7. If a
volume of air corresponding to the remaining part of the liquid flow is
supplied, air will
be lighter than the liquid and hence will be drawn into the ejector 7 instead
of water.
The system will then adjust itself down again until the flow of water and
particles 2
entering the chamber 4 correspond to the liquid flow passing through the pump
13,
while supplied air is drawn towards the ejector 7 instead of entering the pump
13.
Without supply of gas, only the particles 2 floating or sinking will be fed to
the
ejector 7, if the ejector is positioned at the top of the chamber 4 for
floating particles
2, or at the bottom of the chamber 4, if the particles 2 sink. The particles 2
must then
be much larger or lower density than the liquid, so that the particles when I
the
chamber 4 will be able to leave the water flow due to own weight or buoyancy.
If not,
the liquid flow will feed the particles 2 forward until the particles are
forced against
the outlet(s), and after a while clog the outlet(s).
In such latter case it may be necessary to use for example a rotating sieve 30
as outlet 6, moving the particles 2 forced against the outlet 6 towards the
inlet of the
ejector 7 due to the rotation of the sieve 30, ref. the arrows in Figures 6
and 7. As
shown, while the particles and the liquid flow is in a direction to the left
in the
drawing, the direction of rotation of the rotating sieve is a clockwise
direction. It
should be noted that the embodiment disclosed in Figures 6 and 7, i.e. an
embodiment with a rotating sieve 30, supply of gas/air may be superfluous. Not
with-
CA 03029442 2018-12-07
WO 2017/213511
PCT/N02016/050124
12
standing the above, it should be noted, however, that the disclosed embodiment
may
also function in the intended manner even if a gas is supplied.
The embodiment disclosed in Figures 6 and 7, i.e. use of a rotating sieve,
differs from the embodiments disclosed in Figures 1 to 5 in that the outlet 6
for
supply of a liquid to the outer chamber 6 is configured or formed as a self-
cleaning or
rinsing sieve. The sieve may be ion the form of a rotating, cylindrically
shaped sieve
30 or a rotating, band sieve, either being driven by a separate motor 28 (only
indicated in Figure 8).
At the inlet to the ejector 7, one or more one or more nozzles 25 forcing
liquid
through sieve or filter 30 out through the outlet 6 from the side facing
towards the
chamber and into the chamber 4. Particles 2 following the outlet 6 when
rotating, will
be drawn towards the nozzles 25 where the particles are forced away from the
outlet
6 by the flow of liquid out of the nozzles 25, and hence into the inlet of the
ejector 7.
A closed wall 26 guides the particles and the flow of liquid from the nozzles
25 into
the ejector 7.
As shown in Figure 8, a sieve 27 protects the particles 2 against the tough
and hard water flow out of the ejector 7, until the particles 2 and water flow
out from
the ejector are mixed downstream in the pipeline 15, such mixing occurring at
a
distance downstream of the outlet of the ejector 7where the velocity has
decreased
to a level that does not cause any harm to the particles.
30
