WO2017178710A1

WO2017178710A1 - Cavitation arrangement for removing harmful substance from fluid

Info

Publication number: WO2017178710A1
Application number: PCT/FI2017/050277
Authority: WO
Inventors: Leino PEKKA; Walter Eichinger
Original assignee: Nofa Oy
Priority date: 2016-04-14
Filing date: 2017-04-12
Publication date: 2017-10-19
Also published as: FI20165323A; FI127076B

Abstract

An invention relates to cleaning of a fluid, especially cleaning of drinking water or waste water by using ultrasonic waves and a cavitation. The inventions concerns an arrangement (101) for removing a harmful substance from a fluid (102), wherein a tubular space (103) has an inlet (104) for receiving the fluid and an outlet (105) for ejecting the fluid. The arrangement comprises a cavitation element (106) that is configured to rotate inside the tubular space to cause a cavitation in the fluid, the cavitation element tapering towards its top (109) so that a bottom (110) of the cavitation element is wider than the top and an axel intended for rotating the cavitation element is located at a line (111) that penetrates the top and the bottom's midpoint (112). The arrangement further comprises at least one acoustic power transducer (107) for generating sound waves (108), said at least one acoustic power transducer to be located such that the sound waves are targeted to the fluid under an influence of cavitation, and a whirl element (113) for driving the fluid inside the tubular space to a spiral movement (114) towards the top of the cavitation element and the cavitation element's surface from the top to the bottom, the spiral movement contributing the breaking of the molecules.

Description

Cavitation arrangement for removing harmful substance from fluid

Technical field: an invention relates to cleaning of a fluid, especially cleaning of drinking water or waste water from harmful substances by using ultrasonic waves and a cavitation.

Background of the invention Fluids have such property that they don't resist deformation, or resist it only slightly because of viscosity. Fluids also have the ability to flow and they take on the shape of a container. Drinking water is an example of a fluid which should include purely water. A fluid may, however, contain different liquids and gases. Waste water is an example of fluid that contains mostly water but also gases and particles. Cleaning of a fluid means that a harmful substance is removed from the fluid. There are different criteria which is harmful substance when discussing drinking water or waste water.

A harmful substance may be organic, i.e. it includes microbes, such bacteria and arks. Another microbe group comprises moulds, yeasts, and microscopic protozoans. Also viruses can be classified into microbes. Harmful substance may contain an inorganic substance such as phosphates. The phosphates are harmful in drinking water but a small amount of phosphate is allowed in waste water. An antibiotic is a medicine that is originated from a substance produced by microbes. For example, penicillin is an antibiotic. The antibiotic is useful when it cures a patient, but harmful when it ends to a sewer or another location because then a new bacteria population, which is resistant to the antibiotic, may arise

A chemical compound is composed of two or more different chemical elements which have reacted together. The amounts of the chemical elements are in the chemical compound in a certain relation to each other. For example, water is a chemical compound containing two times more hydrogen atoms than oxygen atoms. A harmful substance comprises chemical compounds that are included in an organic substance and/or an inorganic substance, and/or in microbes. The harmful substance can be removed from a fluid by breaking atom bindings inside the harmful substance, i.e. by breaking molecules included in the fluid. Removing of the harmful substance means, in practice, that harmful chemical compounds come apart and/or microbes die. There are several methods for removing a harmful substance from a fluid. The harmful substance can be removed chemically from the fluid by adding into the fluid such compound that reacts with the harmful substance. For example, compounds for eliminating bad odour are used in chemical toilets. Chemicals may be toxic or otherwise harmful, which is a drawback of chemical based cleaning methods.

A membrane can be understood as a selective barrier. It allows some particles to pass through but stops others. Particles to be stopped are, for example, molecules, ions, and bacteria. A filter is intended for bigger particles than a membrane. Membranes are generally classified into synthetic membranes and biological membranes. A drawback of them is that they are expensive and cleaning of them is difficult or impossible.

Some cleaning methods are based on use of ultrasonic waves. For example, there exist ultrasonic cleaners by which consumers can clean their jewels and other small- sized objects. The ultrasonic cleaners generate ultrasonic waves into tap water or into other liquid that includes the objects to be cleaned. A drawback of ultrasonic methods is that in addition to ultrasonic waves also other actions are needed for cleaning fluids.

The performance of the cleaning methods based on ultrasonic waves has been increased by causing a cavitation in a fluid to be cleaned. The cavitation is a natural phenomenon due to which a liquid start to boil because a pressure decreases locally in the fluid. This kind of local under pressure can created, for example, by means of a propeller. In addition to the cavitation, some other actions, such as adding ozone or another gas into the fluid, can utilize to increase the performance of the cleaning method.

US8329043 describes a method and device for treating a liquid. The liquid is introduced into a space in which a mechanical cavitation element acts upon the liquid while gas is supplied into the region of the surface of the cavitation element. The gas can be retained in the liquid by moving the cavitation element and sound waves are introduced directly into the liquid by at least one acoustic power transducer.

CN1120807 describes a method for treating organic waste water by a magnetic field and supersonic waves.

US20140007793 describes certain shapes for a cavitation element. Those shapes should result in a powerful cavitation. WO2015024654 describes a device for the treatment of water by a cavitation. The device comprises annular structures that are rotatable in opposite directions.

JP04392540 describes an apparatus for dispersing micro-bubbles in a water to be cleaned. The apparatus comprises a rotatable part having a form of an ice drill.

The prior art still involves challenges for removing harmful substance from a fluid. One challenge is shaping of a cavitation element and the preparing of the fluid so that an acoustic power transducer can break with sound waves (ultrasonic waves) the most efficient manner molecules in the harmful substance.

Another challenge is placing and targeting the acoustic power transducer in a tubular space so that the all needed molecules can be broken even when a great amount of the fluid flows in the tubular space.

Another challenge is controlling the flow of the fluid depending on a fluid analysis. In more detail, if the fluid analysis indicates that the fluid is cleaned, the flow is appropriate. Otherwise, the operation of the cleaning arrangement should be adjusted.

Summary of the invention

Removing harmful substance from fluid may mean, for example, reuse of the fluid, or that the fluid is clean enough to be emitted to the nature.

One aspect of the invention is that it provides a certain shape for a cavitation element and, in addition, it provides a whirl element for causing a spiral movement into a fluid to be cleaned, such that the certain shape of the cavitation element and the spiral movement prepares the fluid and a harmful substance included it in such manner that sound waves can efficiently break molecules included in the harmful substance.

A basic arrangement for removing a harmful substance from a fluid comprises: a tubular space having an inlet for receiving the fluid and an outlet for ejecting the fluid, a cavitation element that is configured to rotate inside the tubular space to cause a cavitation in the fluid, and at least one acoustic power transducer for targeting sound waves to the fluid, the sound waves being intended for breaking molecules which are included in the harmful substance.

In one embodiment the basic arrangement (as described in the above) further comprises a whirl element and a cavitation element which has a specific shape. In more detail, in a cavitation arrangement in accordance with the invention the cavitation element tapers towards its top so that a bottom of the cavitation element is wider than the top and an axel inside the cavitation element is located at a line that penetrates the top and the bottom's midpoint, and the whirl element is intended for driving the fluid inside the tubular space to a spiral movement towards the top of the cavitation element and the cavitation element's surface from the top towards the bottom, the spiral movement contributing the breaking of the molecules with the sound waves. One aspect of the invention is placing the acoustic power transducers in the tubular space so that at least one of them is located in the middle of the tubular space or its proximity to break efficiently molecules in the harmful substance.

In one embodiment the cavitation arrangement comprises a technical space for placing said at least one acoustic power transducer. This technical space is arranged inside the tubular space and is coupled with a support structure to an inner surface of a body limiting the tubular space such that, excluding the support structure, the technical space is separated from the body.

One aspect of the invention is a possibility to continue removing harmful substance from the fluid, if the fluid analysis indicates that the fluid is not cleaned enough. In one embodiment the cavitation arrangement comprises a return pipe for conducting the fluid from a part of the tubular space locating between the cavitation element and the outlet back to that part of the tubular space which is located between the inlet and the cavitation element. The cavitation arrangement further comprises a flow adjustment mechanism for a flow of the fluid, such that at least part of the flow is guidable by the flow adjustment mechanism to the return pipe. Brief description of the drawings

For a more complete understanding of examples and embodiments of the present invention, reference is now made to the following descriptions taken in connection with the accompanying drawings in which: FIGURE 1 shows an arrangement for removing a harmful substance from a fluid,

FIGURE 2A shows a fluid in spiral movement towards a cavitation element,

FIGURE 2B shows cavitation element having a shape of a pyramid,

FIGURE 2C shows cavitation element whose bottom is extra wide,

FIGURE 3A shows arrangement comprising a magnetize element, FIGURE 3B shows arrangement comprising a gas element,

FIGURE 3C shows an appropriate mutual order for elements in a tubular space,

FIGURE 4A shows a cavitation element that is supported at its both ends,

FIGURE 4B shows a three-point support,

FIGURE 5A shows a suction element for creating suction at a cavitation element, FIGURE 5B shows helical rifling in a tubular space,

FIGURE 6A shows a technical space for a whirl element and magnetize element, FIGURE 6B shows a technical space for an acoustic power transducer, FIGURE 6C shows placing acoustic power transducers to a technical space, FIGURE 7 shows a space arrangement for acoustic power transducers, FIGURE 8A shows a return pipe for a fluid,

FIGURE 8B shows a return pipe and a closure element, FIGURE 9 shows a pipe arrangement. Detailed description of the invention

It is appreciated that the following embodiments are exemplary. Although the specification may refer to "one" or "some" embodiment(s), the reference is not necessarily made to the same embodiment(s), or the feature in question may apply to multiple embodiments. Single features of different embodiments may be combined to provide further embodiments.

FIG. 1 shows a cavitation arrangement 101 for removing a harmful substance from a fluid 102. Arrangement 101 comprises a tubular space 103 which has an inlet 104 for receiving fluid 102 and an outlet 105 for ejecting fluid 102. Arrangement 101 comprises a cavitation element 106 that is configured to rotate inside tubular space 103 to cause a cavitation in fluid 102. Arrangement 101 further comprises at least one acoustic power transducer 107 for targeting sound waves 108 to fluid 102, sound waves 108 being intended for breaking molecules included in the harmful substance.

The cavitation element 106, in accordance with arrangement, 101 tapers at its one end to a top 109. A bottom 110 of cavitation element 106 is wider than top 109. An axel, which is rotatable with cavitation element, or to relation which cavitation element 106 is rotatable, is located at a line 111 penetrating top 109 and a midpoint 112 of bottom 110. The axel is substantially parallel with tubular space 103. Arrangement 101 further comprises a whirl element 113 for driving fluid 102 inside tubular space 103 to a spiral movement 114 towards top 109 of cavitation element 106 so that fluid 102 circles line 111. A surface of cavitation element 106 continues from top 109 towards bottom 110 and spiral movement 114 contributes the breaking of the molecules with sound waves 108.

Some molecules have so weak atom bindings that whirl element 113, cavitation element 106, and at least one acoustic power transducer 107 provide enough breaking power to break them. For example, the most bacteria can be killed with the shown arrangement 101. However, breaking the bacteria's DNA requires more breaking power. In the following figures 3 A - 3C arrangement 101 comprises additional elements for increasing the breaking power and for splitting molecules in the harmful substance. There are various implementations for cavitation element 106 and whirl element 113. The following examples concern these implementations. In one embodiment cavitation element 106 is coupled to an angle gear 115 and angle gear 115 is coupled to a drive axle inside a support 116. Support 116 resembles a keel and is coupled to a body limiting tubular space 103. The body is, for example, a pipe made of plastic, cast iron, stainless steel, or bronze. Fluid 102 can easily pass support 116 because it resembles the keel. Cavitation element 106 can be rotated through angle gear 115 and the drive axle. In one embodiment whirl element 113 comprises a propeller and an angle gear 117 which is coupled to a drive axle inside a support 118. Support 118 is coupled to the body limiting tubular space 103. A power sources intended for rotating said drive axles are omitted from the figure. Support 116 and support 118, and other support (structures) related to the present invention may be separated parts which are attached to the body, for example, by bolts. Alternatively, support 116 and/or support 118 can be manufactured by moulding them together with the body (or a part of the body) in order to make them more durable. The moulding can be performed by using plastic, such as polypropylene or polyethylene.

Alternatively, a metal, such as aluminium or cast iron, or an alloy, such as bronze, can be used in the moulding.

In one embodiment acoustic power transducers 107 are placed on the inner surface 119 of the body at both sides of tubular space 103. Acoustic power transducers 107 are configured to produce sound waves and target them into fluid 102. In one embodiment acoustic power transducer 107 is configured to produce ultrasonic waves so that acoustic power transducer 107 is oscillated with electricity on ultrasonic frequency, which cause mechanical oscillation and creates ultrasonic waves into fluid 102. Fluid 102 includes microscopic vacuum bubbles in liquid because of the cavitation created by cavitation element 106. The ultrasonic waves cause pressure differences to the liquid and due to the pressure differences the vacuum bubbles collapse. The collapsing of the vacuum bubbles creates energy (heat) that breaks molecules in fluid 102.

Usually, fluid 102 should make at least 2-3 cycles in spiral movement 114 around line 111 before reaching top 109 of cavitation element 106. The spiral movement 114 shown in figure 1 includes two and half cycles. In one embodiment the required cycles to fluid 102 are made by a basic propeller whose angle of attack to fluid 102 is unchangeable. There are several possibilities to affect spiral movement 114, and by means of spiral movement 114, to the cavitation. In one embodiment the propeller is manufactured so that its angle of attack to the fluid is alterable. When said angle of attack is altered also spiral movement 114 alters. There are also propellers whose angle of attack to the fluid is alterable by a motor. These last mentioned propellers provide the best possibilities to create different spiral movements 114.

In one embodiment the rotation direction of whirl element 113 is adjustable. In other words, the propeller included in whirl element 113 can be rotated to clockwise or counter-clockwise. When this feature of whirl element 113 is combined with a propeller whose angle of attack to the fluid is alterable, it is possible to alter spiral movement 114 so that fluid 102 flows in tubular space 103 clockwise or counter-clockwise towards cavitation element 106 and causes a different cavitation depending the rotation direction of fluid 102. Generally speaking, the cavitation is stronger when whirl element 113 and cavitation element 106 rotate to opposite directions. On the other hand, the throughput in arrangement 101 is higher when whirl element 113 and cavitation element 106 rotate to the same direction and, due to the higher throughput, more fluid 102 can be processed.

An operator or software, which runs the arrangement, has some means to detect whether the harmful substance is vanished from fluid 102 or not. If the harmful substance is vanished, it is reasonable to continue rotating the whirl element 113 and cavitation element 106 to the same direction and use the arrangement at high throughput. If the harmful substance, however, is not vanished, the rotation direction of whirl element 113 can be turned to increase the cavitation.

In one embodiment the rotation direction of cavitation element 106 is adjustable. Therefore almost same kinds of effects (either the strong cavitation or the high throughput) can be achieved by means of cavitation element 106. It is also possible that the rotation direction of whirl element 113 and the rotation direction of cavitation element 106 are both adjustable.

The following three figures 2A, 2B, and 2C show examples of cavitation element 106 so that cavitation element 106 is viewed inside tubular space 103 from top 109 towards bottom 110 of cavitation element 106. FIG. 2 A shows fluid 102 in spiral movement 114 towards top 109 of cavitation element 106. The surface of cavitation element 106 continues from top 109 to bottom 110 of cavitation element 106 and includes projections 201 to increase the cavitation. Support 116 attaches cavitation element 106 to inner surface 119 of the body. In this example cavitation element 106 has a shape of a cone and projections 201 have a shape of a lamella, i.e. each projection 201 has a thin, plate-like structure.

FIG. 2B shows cavitation element 106 having a shape of pyramid. Cavitation element 106 tapers from the bottom 110 of a pyramid towards the top 109 of the pyramid. When rotating cavitation element 106 in fluid 102 its (four) edges 211 cause a cavitation. If needed, projections on the surface of cavitation element 106 increase the cavitation. In addition to the shape of cone and the shape of pyramid, other such shapes can be formed that cavitation element 106 tapers gradually from the bottom to the top. This kind of shape causes at least some fluid pressure against whirl element 113 (not shown) when cavitation element 106 rotates in fluid 102. Whirl element 113, however, causes a greater fluid pressure and therefore fluid 102 proceeds towards outlet 105 of the tubular space.

FIG. 2C shows cavitation element 106 whose bottom 110 is clearly wider than its top 109. Bottom 110 locates close to inner surface 119 of the body limiting tubular space 103, thus a space 221 between bottom 110 of cavitation element 106 and the inner surface 119 of the body is narrow. In one embodiment whirl element 113 (not shown) is arranged to increase fluid pressure inside tubular space 103 by its rotation. The rotation of whirl element 113 causes a strong pressure in tubular space 103 in proximity of cavitation element 106, especially when space 221 between bottom 110 of cavitation element 106 and inner surface 119 of the body is narrow as in the figure.

In one embodiment a rotation speed of at least another element is adjustable: whirl element 113 and/or cavitation element 106. Increasing of the rotation speed of whirl element 113 increases the fluid pressure so that, due to the fluid pressure, at least one the following result is achieved: a strong cavitation and/or a high throughput. The throughput is low in many prior art arrangements. In other words, the amount of the fluid to be cleaned per a time unit is low, which makes the operation inefficient. One benefit of whirl element 113 is that it increases the throughput by forcing a great amount of fluid 102 per a time unit to pass cavitation element 106. FIG. 3 A shows arrangement 101 comprising a magnetize element 301 for magnetizing fluid 102. Magnetize element 301 is configured to create a magnetic field 302 for weakening the molecules in the harmful substance. In one embodiment magnetizing element 301 comprises two magnets 303, 304 at the opposite sides of tubular space 103. Magnets 303, 304 have opposite poles to create magnetic field 302 between them.

FIG. 3B shows arrangement 101 comprising a gas element 311 for weakening the molecules by means of gas bubbles 312. Gas element 311 comprises a nozzle 313 for introducing the gas into fluid 102 in tubular space 103. An appropriate location for nozzle 313 is close to the top of cavitation element 106 because then spiral movement 114 caused by whirl element 113 spreads gas bubbles 312 on the surface of cavitation element 106. An appropriate gas for arrangement 101, for example, air, oxygen, or nitrogen.

FIG. 3C shows one appropriate mutual order for the elements in tubular space 103. The applicant has made tests in which magnetize element 301 and gas element 311 were detected to enhance the ability of arrangement 101 to break molecules when those elements were used together with whirl element 113 and cavitation element 106. In one embodiment the elements are situated in tubular space 103 in the following order starting from inlet 104: whirl element 113, magnetize element 301, gas element 311, and cavitation element 106 as the last element. At least one acoustic power transducer 107 is further placed in proximity of cavitation element 106 where the cavitation is the strongest. A similar arrangement has been tested several times and according the test results also the most challenging molecules of the harmful substance get broken so that the harmful substance cannot anymore be detected in the fluid. On the other hand, if molecules are less challenging and can be broken without gas, there is no need to use the gas (all the time).

FIG. 4A shows cavitation element 106 supported at its both ends to reduce resonance during the operation of arrangement 101. In more detail, axel 400 inside cavitation element 106 is supported by a support structure 401 at top 109 of cavitation element 106 and by another support structure 402 at bottom 110 of cavitation element 106.

In this example axel 400 (marked with a dot line) is a fixed axel, i.e. it is not rotatable.

Cavitation element 106 is attached to a pulley 403 which is located inside cavitation element 106. Pulley 403 is an outer surface of a motorized pulley. Pulley 403 includes an electric motor for rotating pulley 403 and cavitation element 106. Pulley 403 is attached with ball bearings, or with another type of bearing, to axel 400 and axel 400 is attached to support structures 401, 402 from its both ends.

Each of support structures 401, 402 is a keel shaped support that attached to the inner surface 119 of the body. Support 402 is hollow and includes a passage 404 for the electric wires of the motorized pulley. Passage 404 starts outside of tubular space 103 and includes a through-hole between the tubular space 103 and support 402, and another through-hole between the support 402 and axel 400. Passage 404 ends to the power source locating inside pulley 403. FIG. 4B shows a three-point support 411 whose three rods 412-414 are attachable to three points 415-417 on the inner surface 119 of the body. Three-point support 411 can be utilized in arrangement 101 to support at least one of the following elements: whirl element 113, magnetize element 301, gas element 311, or cavitation element 106. For example, cavitation element 106 can be attached to inner surface 119 of the body with two three-point supports 411 so that structures 401 and 402 are implemented as three-point supports. Rods 412-414 can be hollow for a wire passage or for gas. Each rod 412-414 may include a through-hole which operates as nozzle 313 for introducing the gas into fluid 102.

FIG. 5 A shows a suction element 501 for creating a suction at cavitation element 106 towards outlet 105 of tubular space 103. In more detail, suction element 501 causes the suction in space 221 that is located between bottom 110 of cavitation element 106 and the inner surface 119 of the body. The surface of suction element 501 is formed so that a rotation of it causes the suction. Suction element 501 includes lamellas 502 with a large area. In this embodiment cavitation element 106 and suction element 501 are attached to the same motorized pulley 503. Pulley 503 is supported with three-point support 411 at top 109 of cavitation element 106 and with another three-point support 411 at top 504 of suction element 501. In another embodiment cavitation element 106 and suction element 501 are rotatable by different power sources and therefore they may have different rotation speeds and different rotation directions. In addition to the suction, suction element 501 increases the cavitation in tubular space 103. Cavitation element 106 and suction element 501 cause together the cavitation which starts at top 109 of cavitation element 106 and continues towards outlet 105. FIG. 5B shows a helical rifling 511 included in tubular space 103. Helical rifling 511 comprises is this example six helical grooves, such as groove 512, and is configured to cause spiral movement 114 for fluid 102, i.e. it can operate as whirl element 113. Helical rifling 511 is an alternative to a propeller. In one embodiment the helical rifling 511 is motorized and rotatable. Helical rifling 511 can be motorized, for example, by using an angle gear and an electric motor outside of tubular space 103, or by using a motorized pulley.

In another embodiment, helical rifling 511 is fixed, i.e. helical rifling 511 is an unmovable part in the body limiting tubular space 103, but it is capable to create spiral movement 114 when suction element 501 sucks fluid 102 through it.

In the above pulley 503 is an example of a technical space intended for components of arrangement 101. Also other components of arrangement 101 can be placed inside the technical space.

FIG. 6A shows a technical space 601 for whirl element 113 and magnetize element 301. Technical space 601 is supported at its ends with three-point supports 602, 603, and between whirl element 113 and magnetize element 301 with a third three-point support 604. Technical space 601 is located in the middle of tubular space 103 and fluid 102 can flow around it towards top 109 of cavitation element 106. Whirl element 113 comprises a motorized pulley 605 and a propeller 606 that is attached to the outer surface of motorized pulley 605. The axle of motorized pulley 605 is attached from its ends to three-point supports 602, 604.

Three-point support 604 supports one end of magnetize element 301 and three- point support 603 supports the opposite end of magnetize element 301 and also top 109 of cavitation element 106. Magnetize element 301 has a shape of cylinder so that the side of cylinder is parallel with tubular space 103. The surface of cylinder is made of plastic in order that magnetize element is able to create magnetic field 607 through the surface. Because of its position in the middle of the tubular space 103 and its orientation in relation to tubular space 103 is the before mentioned, magnetize element 301 can target magnetic field 607 to fluid 102 in an efficient manner so that magnetic field 607 fully covers a part of tubular space 103 without any dead zones. FIG. 6B shows a technical space 611 for at least one acoustic power transducer 107. Technical space 611 is a small-sized protrusion that is attached to three-point support 411 at top 504 of suction element 501. Technical space 611 points towards outlet 105 of tubular space 103 where tubular space 103 is open for sound waves 612. In one embodiment at least one acoustic power transducer 107 is attached to technical space 611 and targeted parallel with the tubular space 103. In the figure transducer 107 can introduce sound waves 612 so that sound waves 612 meet inner surface 119 of the body on an area 613 that continues around inner surface 119. At area 613, tubular space 103 does not include any dead zone into which sound waves 612 could not enter. Generally speaking, if sound waves cannot enter in fluid 102 into a certain area, this certain area is a dead zone where molecules don't get broken, and because the molecules don't get broken, a portion of a harmful substance may pass arrangement 101 and therefore cleaning of fluid 102 may fail.

FIG. 6C shows another example of placing acoustic power transducers to technical space 620. A first view 621 shows benefits of technical space 620 and a second view 622 illustrates why it is reasonable to place the acoustic power transducers on the technical space 620. Technical space 620 is a small- sized protrusion which is parallel to tubular space 103 and which is coupled at its one end to a support 623 and support 623 is coupled to inner surface 119 of the body that limits tubular space 103. In one embodiment arrangement 101 comprises a plurality of acoustic power transducers 107, 624-626 that are arranged with even distances around the surface of technical space 620. In this example four acoustic power transducers 107, 624-626 are arranged on the surface of technical space 620 so that they are targeted towards inner surface 119 of the body (transducer 107 upwards, transducer 624 downwards, transducer 625 towards, and transducer 626 away). Each acoustic power transducers 107, 624-626 is able to introduce sound waves at a sector whose central angle is at least 90°. Because there are four acoustic power transducers and each of them has a sound wave sector with at least 90° central angle, the four acoustic power transducers are able to cover 360°. In other words, acoustic power transducers 107, 624-626 are arranged so that their sound waves enter to a uniform area that continues around inner surface 119 of the body. First view 621 shows only sound waves introduced by transducers 107 and 624. It should also be noticed that the coverage of 360° is possible to achieve by using another number of acoustic power transducers than four. For example, three acoustic power transducers is an appropriate number for the coverage of 360°, if each transducer has a sound wave sector with at least 120° central angle.

Second view 622 shows tubular space 103 and two acoustic power transducers 627, 628 placed opposite to each other, on the both sides of tubular space 103. Sound waves introduced by transducer 627 and sound waves introduced by transducer 628 meet each other at the middle of tubular space 103. A problem related to second view 622 is that the sound waves of transducers 627, 628 disturb each other. Due to this disturb effect, there are dead zones 629, 630 around the both transducers 627, 628. For example, the sound waves of transducer 627 disturb the sound waves of transducer 628 and hinder their entering into the area of dead zone 629. The disturb effect can be avoided by placing transducers 627, 628 so that they don't locate opposite to each other. Then the sound waves of transducers 627, 628 reach the opposite side of tubular space 103. In this manner it is possible to solve the problem related to the disturb effect, but the sound waves must travel the distance of the diameter of tubular space 103. Said distance is about two times longer than the distance which sound waves travel in first view 621. The longer the distance the more the sound waves weaken. A benefit of technical space 620 shown in first view 621 is the following. When acoustic power transducers 107, 624-626 introduce sound waves, the sound waves need to travel only a half of the distance of diameter of tubular space 103 assuming that acoustic power transducers 107, 624-626 are placed on middle of tubular space 103.

FIG. 7 shows a technical space 700 for a space arrangement 701. Arrangement 701 is intended for removing a harmful substance from a fluid 702 and it comprises a tubular space 703 which has an inlet 704 for receiving fluid 702 and an outlet 705 for ejecting fluid 702. Arrangement 701 comprises any cavitation element (not shown) that is configured to rotate inside tubular space 703 to cause a cavitation to fluid 702.

Arrangement 701 further comprises at least one acoustic power transducer 706 for targeting sound waves 707 to fluid 702, sound waves 707 being intended for breaking molecules included in the harmful substance. Technical space 700 enables that said at least one acoustic power transducer 706 can be placed so that said at least one acoustic power transducer 706 is capable to target sound waves 707 to fluid 702 to bread the molecules. Technical space 700 is arranged inside tubular space 703 and is coupled with a support structure 708 to an inner surface 709 of a body limiting tubular space 703. Excluding support structure 708, technical space 700 is separated from the body.

In one embodiment arrangement 101 comprise measurement equipment for measuring whether fluid 102 is cleaned or not. It is possible to chain a plurality of arrangements 101 so that fluid 102 flows through the plurality of arrangements 101 in order to continue cleaning of fluid 102. Alternatively, a return pipe can be used.

FIG. 8A shows a return pipe 801 to conduct fluid 102 from a part of tubular space 103 locating between cavitation element 106 and outlet 105 back to that part of tubular space 103 which is located between inlet 104 and cavitation element 106. In one embodiment arrangement 101 comprises a flow adjustment mechanism 802 for flow of fluid 102, such that at least part of the flow is guidable by flow adjustment mechanism 802 to return pipe 801. Flow adjustment mechanism 802 comprises a branch pipe 803 which has two branches so that one of branches is configured to operate as the outlet 105 and the other branch is configured to operate as a return pipe inlet 804.

In one embodiment flow adjustment mechanism 802 comprises a pump 805 for pumping fluid 102 from return pipe inlet 804 into return pipe 801. Because pump 805 recycles fluid 102 in arrangement 101, the cleaning result of fluid 102 enhances. A benefit of return pipe 801 is that a single arrangement 101 is adequate, i.e. there is no need to chain a plurality of arrangements 101, which means savings in the investment costs.

Regarding to figure 8 A there is an assumption that tubular space 103 can be closed at inlet 104 by a closure element 806, such as a closable port. Generally speaking, when tubular space 103 can be isolated somewhere at inlet 104, or before it, fluid 102 cannot escape through outlet 105 when outlet 105 locates in branch pipe 803 higher (in relation to the earth) than return pipe inlet 804.

Cleaning arrangements can usually be closed by a valve or a closable port. In addition, the cleaning arrangements are usually protected by a sieve (not shown) which prevents large particles to enter at a cavitation element, because the large particles would worsen the breaking of molecules.

In one embodiment pump 805 and helical rifling 51 1 operate as whirl element 113 when tubular space 103 is closed at inlet 104. Pump 805 is arranged to pump fluid 102 from tubular space 103 so that fluid 102 flows through return pipe 801 and through return pipe outlet 807 back into tubular space 103 and into helical rifling 511. Pump 805 recycles fluid 102 until fluid 102 is clean enough. Then pump 805 can be stopped and inlet 104 to tubular space 103 can be opened.

Assuming that fluid 102 flows from a higher position 808 (in relation to the earth) to inlet 104, the gravitation forces fluid 102 to flow from inlet 104 with a pressure into helical rifling 511. Even if helical rifling 511 is an unmovable part in tubular space 103, helical rifling 511 drives fluid 102 due to said pressure to spiral movement 114.

FIG. 8B shows a return pipe 811, a flow adjustment mechanism 812,

measurement equipment 813 for measuring the content of fluid 102, and a control unit 814 comprising a processor and a memory. Flow adjustment mechanism 812 comprise closure element 815 which is, for example, a valve or a port at outlet 105 of tubular space 103.

Measurement equipment 813 is configured to measure fluid 102 independently or in response to a measurement command from control unit 814. A measurement result of measurement equipment 813 indicates, for example, whether the percentage of the harmful substance has reaches a predetermined limit. Control unit 814 is configured to receive the measurement result from measurement equipment 813 and make a deduction on the basis of the measurement result to adjust the operation of arrangement 101. Control unit 814 is further configured to form a control command on the basis of the deduction.

Measurement equipment 813 and control unit 814 are configured to communicate via a wire or wirelessly. In addition, control unit 814 and at least one of the following elements are configured to communicate via a wire or wirelessly: whirl element 113, magnetize element 301, gas element 311, cavitation element 106, suction element 501, or said at least one acoustic power transducer 107.

At least one of the elements 113, 301, 311, 106, or transducer 107 is capable to receive the control command formed by control unit 814. Control unit 814 is capable to make various deductions on the basis of the measurement result it receives. A deduction of control unit 814 is, for example, that outlet 105 of tubular space 103 must be closed, because a measurement result indicates that fluid includes too much the harmful substance. If outlet 105 of tubular space 103 locates far enough from measurement equipment 813, there is time to close outlet 105 with closure element 815 before the harmful substance reaches outlet 105. When closure element 815 is set in the closed position, fluid 102 flows to a return pipe 811 and can be recycled in cleaning arrangement 101.

In one embodiment closure element 815 has two positions: the closed position and an open position. This embodiment is appropriate, if the harmful substance is very dangerous, such as Marburg virus in a drinking water. Then arrangement 101, including control unit 814 and closure element 815, is configured to operate fast enough, in relation to the distance between measurement equipment 813 and closure element 815, to close outlet 105 with closure element 815 before the harmful substance reaches outlet 105.

For example, if it takes ten seconds to close outlet 105 with closure element 815 and fluid 102 flows one meter in a second, the distance between measurement equipment 813 and closure element 815 should be more than ten meters because then outlet 105 can be closed before any portion of the harmful substance reaches outlet 105. Of course, the margins should not be too tight. It is reasonable to implement arrangement 101 so that the distance between measurement equipment 813 and closure element 815 is long enough. In one embodiment closure element 815 has the closed position and a number of open positions. This embodiment is appropriate, if fluid 102 is allowed to temporarily include (a small amount of) the harmful substance. For example, phosphates are such substance in waste water. Arrangement 101 is configured to adjust a size of outlet 105 by closure element 815. For example, the size of outlet 105 may be set to 40% of the maximum size to guide a portion (60%) of fluid 102 to return pipe 811.

In one embodiment whirl element 113 and suction element 501 are configured to operate as a pump that forces fluid 102 to flow through return pine 811.

In one embodiment the control command of control unit 814 is for the closure element to adjust outlet 105. In another embodiment the control command is for some of the following elements: whirl element 113, magnetize element 301, gas element 311, cavitation element 106, suction element 501, or at least one acoustic power transducer 107. The operation of the elements can be adjusted in various manners as described in the above. In one embodiment return pipe 811 is completely or partly closable by a closure element 817. When closure element 817 is its closed position, closure element 817 prevents fluid 102 to flow via return pipe 811 to a wrong direction, i.e. towards outlet 105. Closure element 817 can be controlled by control unit 814. For example, control unit 814 may close outlet 105 (with element 812) and simultaneously open return pipe 811 by opening closure element 817.

FIG. 9 shows a return pipe 900 for a pipe arrangement 901 that is intended for removing a harmful substance from a fluid. Arrangement 901 comprises a tubular space 903 which has an inlet 904 for receiving fluid 902 and an outlet 905 for ejecting fluid 902. Arrangement 901 comprises any cavitation element 906 that is configured to rotate inside tubular space 903 to cause a cavitation in fluid 902. Arrangement 901 comprises at least one acoustic power transducer 907 for targeting sound waves to fluid 902, the sound waves being intended for breaking molecules included in the harmful substance.

Return pipe 900 is intended for conducting fluid 902 from a part of tubular space 903 locating between cavitation element 906 and outlet 905 back to that part of the tubular space 903 which is located between inlet 904 of tubular space 903 and cavitation element 906. Arrangement 901 further comprises a flow adjustment mechanism for a flow of fluid 902, such that at least part of the flow is guidable by the flow adjustment mechanism, such as mechanism 802 or 812, to return pipe 900.

Arrangement 901 can be used in figures 8 A, 8B instead of arrangement 101. Figures 8 A, 8B and the preceding figures and text also concern pipe arrangement 901.

While the present invention has been described in connection with a number of exemplary embodiments, and implementations, the present invention is not so limited, but covers various modifications, and equivalent arrangements, which fall within the purview of prospective claims.

Claims

1. An arrangement (101) for removing a harmful substance from a fluid (102) comprising a tubular space (103) having an inlet (104) for receiving the fluid and an outlet (105) for ejecting the fluid, a cavitation element (106) that is configured to rotate inside the tubular space to cause a cavitation in the fluid, the cavitation element tapering towards its top (109) so that a bottom (110) of the cavitation element is wider than the top and an axel intended for rotating the cavitation element is located at a line (111) that penetrates the top and the bottom's midpoint (112), c h a r a c t e r i z e d in that the arrangement further comprising at least one acoustic power transducer (107) for generating sound waves (108), said at least one acoustic power transducer to be located such that the sound waves are targeted to the fluid under an influence of cavitation, and a whirl element (113) for driving the fluid inside the tubular space to a spiral movement (114) towards the top of the cavitation element and the cavitation element's surface from the top to the bottom, the spiral movement contributing the breaking of the molecules with the sound waves and the spiral movement of the fluid being adjustable with a motor coupled to the whirl element or with a pump capable to pump the fluid towards the whirl element.

2. The arrangement as claimed in claim 1, c h a r a c t e r i z e d in that the arrangement comprises a magnetize element (301) for magnetizing the fluid, the magnetize element being configured to create into the fluid a magnetic field (302) for weakening of molecules.

3. The arrangement as claimed in claim 1, c h a r a c t e r i z e d in that the arrangement comprises a gas element (311) for weakening the molecules by adding gas (312) into the fluid, the gas element comprising at least one nozzle (313) for the gas.

4. The arrangement as claimed in claim 1, characterized in that a shape of the cavitation element is similar to one of the following shapes: a cone, a pyramid.

5. The arrangement as claimed in claim 1, characterized in that the axel inside the cavitation element is supported at its both ends to reduce resonance.

6. The arrangement as claimed in claim 1, characterized in that the whirl element comprises a propeller.

7. The arrangement as claimed in claim 6, characterized in that in order to alter the spiral movement, the propeller's angle of attack to the fluid is alterable.

8. The arrangement as claimed in claim 1, characterized in that the whirl element comprises a helical rifling (511) on an inner surface (119) of a body limiting the tubular space.

9. The arrangement as claimed in claim 1, characterized in that the whirl element is rotatable by the motor (605).

10. The arrangement as claimed in claim 1, characterized in that a rotation speed of at least another element is adjustable: the whirl element, the cavitation element.

11. The arrangement as claimed in claim 1, characterized in that a rotation direction of at least another element is adjustable: the whirl element, the cavitation element.

12. The arrangement as claimed in claim 1, characterized in that the arrangement comprises a suction element (501) whose surface is formed so that a rotation of the suction element causes a suction at the cavitation element towards the outlet.

13. The arrangement as claimed in claim 1, characterized in that the arrangement comprises a technical space (601, 611, 700) for placing said at least one acoustic power transducer, such that the technical space is arranged inside the tubular space and is coupled with a support structure to an inner surface of a body limiting the tubular space and, excluding the support structure, the technical space is separated from the body.

14. The arrangement as claimed in claim 13, characterized in that said at least one acoustic power transducer is arranged to create sound waves lengthwise inside the tubular space.

15. The arrangement as claimed in claim 13, characterized in that the arrangement comprises a plurality of acoustic power transducers (107, 624-626) that are arranged with even distances around the surface of technical space.

16. The arrangement as claimed in claim 15, characterized in that the acoustic power transducers are arranged to create sound waves so that the sound waves proceed towards the inner surface of the body.

17. The arrangement as claimed in claim 1, characterized in that the arrangement comprises a return pipe (801, 811, 900) for conducting the fluid from a part of the tubular space locating between the cavitation element and the outlet back to that part of the tubular space which is located between the inlet and the cavitation element, and a flow adjustment mechanism (802, 812) for a flow of the fluid, such that at least part of the flow is guidable by the flow adjustment mechanism to the return pipe.

18. The arrangement as claimed in claims 8 and 17, characterized in that a pump (805) arranged in the return pipe operates as the pump capable to pump the fluid towards the whirl element.

19. The arrangement as claimed in claim 17, characterized in that the arrangement comprises a branch pipe (803) so that one of branches is configured to operate as the outlet and another of the branches is configured to operate as an inlet (804) of the return pipe.

20. The arrangement as claimed in claim 17, characterized in that the outlet of the tubular space is completely or partly closable by a closure element (815).