WO2018001735A1

WO2018001735A1 - Reactor and method for treating contaminated water

Info

Publication number: WO2018001735A1
Application number: PCT/EP2017/064513
Authority: WO
Inventors: Svenja BIERBAUM; Olaf STREICH; Jörg GRUBE; Wiebke MATTHIAS; Pascal PHILIPPSEN; Jürgen WETZEL
Original assignee: Skf Marine Gmbh
Priority date: 2016-06-30
Filing date: 2017-06-14
Publication date: 2018-01-04
Also published as: DE102016211920A1

Abstract

The invention relates to a reactor (10) for purifying contaminated water, in particular ballast water of a ship. Said reactor has a treatment channel, having a first section (20a), a second section (20c) extending parallel to the first section, and a turning region (20b) lying between the first and the second sections. The first section (20a) has an inlet (11), which is directed at at least one flow-splitting element (16a'), which extends in the direction of the first section. The invention further relates to a method for purifying contaminated water in a reactor, which method comprises introducing the contaminated water and conducting the contaminated water in succession through a first section (20a), through a turning region (20b), and through a second section (20c) of a treatment channel, wherein the contaminated water is divided into at least two partial flows, which flow through the first section (20a) adjacently to each other.

Description

Reactor and process for the treatment of contaminated water

The present invention relates to a reactor and a method for purifying contaminated water.

Various chemical and physical processes are known for treating liquids loaded with solids or microorganisms. Especially in the field of physical processes, filters and centrifugal separators are used to separate unwanted constituents of a liquid. Smaller microorganisms can subsequently be killed. For this purpose, a loaded liquid with ultrasonic waves or ultraviolet light (UV) can be treated in a reactor.

Seagoing vessels are often designed to contain ballast water to improve their stability. Such water contains pollutants and organisms that are often associated with the ecosystem of an area where the intake of water takes place. Now, if the absorbed water is pumped out again in a target area of the ship, the substances and living beings contained therein can enter with the water into a foreign ecosystem. This can lead to far-reaching environmental damage.

For this reason, the delivery of ballast water was regulated. Thus, in certain areas (e.g., ports), it may only be pumped if it has a predetermined quality given by limits. Therefore, the ballast water often needs to be prepared before draining first.

The object of the present invention is to improve a reactor and a process for purifying contaminated water. The object is achieved by a reactor according to claim 1 and a method according to claim 6. Advantageous embodiments are disclosed in the subclaims, the figures and the description.

A reactor according to the invention for cleaning contaminated water (in particular ballast water of a ship) comprises a treatment channel with a first and a second section and with a turning zone lying between the first and the second section. The first and second portions extend parallel to each other, and the first portion has an inlet directed to at least one flow divider element that is in the same direction as the first portion (ie, like the treatment channel in the first portion).

A method according to the invention for purifying contaminated water in a reactor comprises introducing the contaminated water into a first section of a treatment channel in the reactor and passing the loaded water through the first section successively through a second section of the treatment channel extending parallel to the first section through a turning area connecting the first and second sections. The contaminated water is thereby divided (preferably during introduction or in an inlet region in the first section) into at least two partial streams which flow through the first section at least partially (preferably simultaneously) side by side.

The direction of the first or second section is to be understood as meaning the direction of the treatment channel in the respective section, that is to say the direction in which introduced water substantially propagates in the treatment channel. In the turning region of the treatment channel changes its direction, preferably substantially by 180 °. The treatment channel of a reactor according to the invention or of a reactor used in a method according to the invention therefore runs in a turn in the turning region, ie essentially has a hairpin or U-shape whose legs are formed by the first or second section; each of these sections can be understood as a treatment chamber. The inlet defines an inflow direction into the first portion, which is preferably oriented orthogonal to the direction of the treatment channel in the first portion. Inflowing water is thus deflected before it spreads in the first section of the treatment channel, so it can flow through it. This reduces the flow rate and thus increases the treatment time.

The course of the treatment channel thus enables in particular a compact design of the reactor and at the same time a small cross section of the two sections respectively. This allows a maximum exposure of the flowing contaminated water in an area of action of one or more treatment elements and thus its efficient and targeted treatment, for example, successively with different treatment elements.

In particular, the reactor may be substantially circular cylindrical or a straight prism (preferably with a regular polygon, for example with a hexagon or octagon, as a base); the first and the second section preferably extend in the direction of its geometric height (which is to be understood as the description parameter of a circular cylinder or prism and thus independently of the respective orientation); in the case of a circular cylinder, this direction coincides with the direction of the central axis.

In the interior of the reactor, in the axial direction (or in the direction of a prism height), preferably along a central axis of the reactor, a dividing wall is arranged, which is incomplete at one end of the reactor, so that there is a passage and thus the turning region. Preferably, a first side surface of the partition wall forms a wall of the first section of the treatment channel and one of the first opposing second side surface of the partition wall forms a wall of the second section of the treatment channel.

Preferably, one or more treatment element (s) such as in particular UV lamps (preferably in each case in a cladding tube, for example a quartz glass cladding tube) and / or sonotrodes is or are arranged in the treatment channel and / or outside of the treatment channel. Preferably, treatment elements are arranged both in and / or (outside) on the first section and in and / or (outside) on the second section. An invention The method according to the invention preferably comprises treating the loaded water introduced into the reactor with such at least one treatment element.

From such sonotrodes outgoing ultrasound generated in the contaminated water so-called cavitation, ie formation and dissolution of vapor-filled cavities. As a result of the mechanical stress caused by the ultrasound, the stressed water is so heavily stressed that the water phase "breaks up" and small bubbles filled with steam or gas form, which implode again after a short time under the influence of external pressure limited extreme conditions (very high pressures and temperatures) that damage the microorganisms contained in the water.

According to an advantageous embodiment, sonotrodes of a first type may be arranged in and / or on the first section and sonotrodes of a second type in or on the second section, or sonotrodes of a first type may be arranged in a first zone in an inlet region of the first section Furthermore, sonotrodes of a second type may be arranged in a second zone in or on a region of the first section which adjoins the turning region, and sonotrodes of a third type may be arranged in the second section as the third zone. The types can differ by the ultrasound frequencies that can be produced by the respective sonotrodes. Preferred is an embodiment in which the respectively producible ultrasonic frequencies of the first type are lower than those of the second type (which in turn may be lower than those of the third type). Such sonotrodes are or preferably comprise stab sonotrodes, which advantageously extend in the direction of the respective section of the treatment channel.

According to a specific embodiment with three types of sonotrodes, the sonotrodes of the first type (in an inlet zone of the first section) are adapted to produce an ultrasonic field with frequencies of 20-30 kHz, the sonotrodes of the second type (in a zone of the first section which is adjacent to the turning region) are adapted to generate an ultrasonic field with frequencies of 30-50 kHz and the sonotrodes of the third type (in the second section as third zone) are adapted to an ultrasonic field with frequencies of 50-100 kHz produce. By means of the different frequencies, different types of cavitations can be generated, which reaches different microorganisms: Namely, stronger cavitations are produced at lower frequencies than at higher frequencies. Such greater cavitation produces relatively large cavitation bubbles and very strong, localized pressure surges and temperature increases. However, these bubbles are not evenly distributed, and relatively few of these cavitation bubbles are generated, so that they are only achieved rather large microorganisms. On the other hand, the higher the frequency becomes, the larger the number of smaller cavitation bubbles becomes. The distribution of the bubbles in the water phase is more uniform, and thereby increasingly smaller organisms are damaged or killed.

Even with UV light, microorganisms can be eliminated. At least one UV lamp (preferably designed as a flashlight, ie rod-shaped) as the treatment element is preferably arranged in the first and / or second section such that the respective section is fully illuminated with UV radiation (or UV light). According to a preferred embodiment, low-pressure UV lamps which preferably emit UV-C radiation are used as UV lamps. In particular, UV lamps can preferably be used which emit UV radiation at a specific wavelength in the range from 245 nm to 265 nm, in particular preferably about 254 nm. This wavelength permanently damages organs in the contaminated water by destroying the DNA of the organisms.

The number of UV lamps in the first and second sections (or each zone) may be the same, for example, three, four, five, or six, respectively. Alternatively, the two sections (or in at least two of the zones) may comprise different numbers of UV lamps. According to an advantageous embodiment, the number of UV lamps in the first and / or in the second section is variable; thus, the sections can be adapted to the particular requirements (for example, by the quality of the liquid to be purified and / or the purity of the liquid to be achieved) by inserting or fitting a suitable number of UV lamps.

It is particularly advantageous if the at least one treatment element comprises both at least one sonotrode and at least one UV lamp. It has been found that the effect of UV radiation is accompanied by exposure to ultraviolet radiation. sound cavitation has a reinforcing effect. The number of UV lamps in the first and / or second section may be equal to or different from the number of horns in the corresponding section (or the corresponding zone) respectively (or in one, second or each of the zones). According to a specific embodiment, in the first section or in the first zone the same number of UV lamps are arranged as on sonotrodes, for example three each; The same applies preferably to the second section or the second and / or the third zone. According to a further embodiment, the first section has the same number of UV lamps as the second section (eg three, four, five or six UV lamps in each case), while the number of sonotrodes in the first and / or second section (or the first section) , second and / or third zone) may each be smaller or larger than the number of UV lamps in each section. For example, the first section may comprise two zones each having a plurality of sonotrodes, for example three sonotrodes each, and the second section may comprise a single zone with a total of three sonotrodes.

According to a preferred embodiment of a method according to the invention, the introduced contaminated water is passed through the first section and analogously through the second section within at least one second and a maximum of 10 seconds, more preferably no more than 6 seconds (or more preferably no more than 5 seconds). With such an exposure time during which the organisms are exposed to the combination of UV radiation and the ultrasonic field, sufficient treatment of the contained microorganisms can be achieved. According to a particular advantageous embodiment, a residence time of the loaded water in the reactor is a maximum of 10 seconds.

Sonotrodes are preferably arranged in or on the reactor as treatment elements which are connected to different ultrasound generators (so that therefore a first sonotrode is connected to a first ultrasound generator and a second sonotrode is connected to a second ultrasound generator different from the first); In particular, different sonotrodes of the same type can be driven by different ultrasonic generators. Thus, an in-phase oscillation of the various ultrasonic sonotrodes (eg of the same type or in the individual zones) can be avoided. Thus, a weakening of the energy within a zone is avoided because no common resonant frequency arises. An inventive method can analogously Driving different sonotrodes (especially within the same zone) with mutually different ultrasonic generators include.

The flow dividing element extending in the first section in the direction of the first section of a reactor according to the invention effects a division of an introduced flow of contaminated water into at least two partial flows which preferably flow through the first section side by side (or at the same time). Accordingly, the division can be effected in a method according to the invention by means of such a flow splitting element, to which an introduced stream is directed with contaminated water and thus bounces.

Divided in this way, the polluted water can be brought closer targeted to treatment elements in or at the reactor. This can improve the efficiency of the treatment.

The flow dividing element may comprise a rod extending in the direction of the first portion or an element having an edge in this direction. In particular, the flow dividing element may comprise an edge of the dividing wall projecting towards the inlet (which in this case may for example be angled and / or may have a projection).

Preferably, the at least one flow divider is substantially in a plane that bisects an opening of the inlet to the reactor. In particular, the first portion is preferably formed symmetrically to the said plane. In this way, the partial flows generated by the at least one flow sharing element can be formed identically; In particular, the partial flows preferably have essentially the same volume flow. Thus, a uniform treatment of the contaminated water can be effected.

Particularly preferred is an embodiment in which the at least one current-dividing element comprises at least one treatment element extending in the first section, for example at least one stab sonotrode and / or at least one UV lamp (which may be arranged in a cladding tube). In particular, can thus dispensing with an additional (space-claiming) element in the treatment channel.

The two partial flows can, for example, wind essentially in two parallel helices from the inlet into the first section to the turning zone, preferably around one or more treatment elements, which preferably extend in the direction of the first section. In this way, the contaminated water is exposed in a small space on a relatively long treatment path to the influence of the treatment element or the treatment elements. Thus, the removal of the contaminated water to the treatment element (s) is reduced and the duration of treatment (in the form of the treatment route) is prolonged in a small space, thus resulting in an overall improved treatment efficiency.

For effecting such a helical flow guidance, the partial flows in the first section can preferably be deflected several times, for example by being directed onto an inner wall of the first section. In particular, the inlet of a reactor according to the invention is preferably oriented orthogonal to the direction of the first section of the treatment channel, preferably directed towards a central axis of the reactor.

Pumped polluted water thus has a directional component transverse to the direction of the first section (e.g., radially toward a central axis of the reactor) and therefore preferably bounces sequentially at different portions of the inner wall, each undergoing a change of direction.

According to an advantageous embodiment of a method according to the invention, the reactor is arranged or aligned during passage of the contaminated water, that the treatment channel in the first section from an inlet to the turning area substantially vertically downwards and in the second section from the turning area to an outlet substantially runs vertically upwards. A reactor according to the invention is analogously preferably designed to be used in such an orientation; In particular, in a polluted water purification plant (eg in a ballast water treatment plant of a ship), such an oriented reactor according to one of the embodiments disclosed in this document.

By means of such an orientation, a residence time of the contaminated water in the reactor can be controlled particularly suitably, for example by pulsed introduction.

Before cleaning the polluted water in the reactor this is preferably filtered; a reactor according to the invention can be connected to a filter system, which is flowed through by the charged water before it is introduced into the reactor. In this case, in a filtration stage, the large amounts of water (organisms and solids) whose size is greater than 10-100 μιη, more preferably 25-50 μιη, are separated. The filter system can to filter fabric with a mesh size of 10 μιη, 20 μιη, 25 μιη, 30 μιη, 40 μιη, 50 μιη and / or 100 μιη include.

According to advantageous embodiments of the present invention, a reactor according to the invention is installed according to one of the embodiments disclosed herein for cleaning ballast water on a ship, or a method according to the invention is carried out according to one of the embodiments disclosed in this document on a vessel for cleaning ballast water.

In the following preferred embodiments of the invention will be explained in more detail with reference to drawings. It is understood that individual elements and components can be combined differently than shown. Reference numerals for corresponding elements are used across figures and may not be rewritten for each figure.

They show schematically:

FIG. 1 shows a side view into a reactor according to the invention according to an embodiment of the present invention;

FIG. 1b shows the course of the treatment channel of a reactor shown in FIG. and

Figure 2: a cross section of a reactor according to the invention with flow guidance. Figure la provides a side view into a reactor 10 according to an exemplary embodiment of the present invention. The rector 10 is substantially circular-cylindrical with a substantially circular base and cover surface 17b or 17a and a lateral surface 18. In an area of the lid surface 17a (or in a quarter of a longitudinal extension of the reactor adjoining the lid surface), the reactor 10 has an inlet 11 and an outlet 12, respectively. Inlet 11 and outlet 12 are each arranged in a lateral surface of the reactor and aligned orthogonal to the height H of the reactor.

A diameter of a base of such a reactor is in the example shown substantially half as large as the height of the reactor. With such dimensions can (analogous to a prismatic reactor) particularly advantageous flow and treatment shares can be achieved.

The inlet leads into a treatment channel located inside the reactor, which has a first section 20a and a second section 20c and a turning section 20b therebetween. The first and second sections are parallel to each other in opposite directions; they are separated from one another by a partition wall 14 extending parallel to their (passage) direction and which can be seen in the illustration of FIG. 1a in a longitudinal section. In the area of the bottom surface, the dividing wall 14 leaves open a passage 19 which connects the first and the second section in the turning area 20b.

The outlet 12 is arranged mirror-symmetrically to the inlet 11; the partition 14 is arranged in the mirroring plane. Furthermore, the illustrated reactor 10 on its lateral surface connecting piece 13 for (not shown) UV sensors. Such UV sensors are preferably arranged in the reactor and adapted to measure an intensity of UV radiation arriving at its respective position (and at the respective distance to one or more of the UV lamp (s)). By means of a control device (not shown), which can be connected to the UV sensors via the connecting pieces, the respective UV lamp can then be set (or regulated) as a function of the measured intensity. In Figure 2 it can be seen that the reactor 10 eight Such connection piece 13 has, alternatively, a different number of connection pieces is possible.

In the first section 10a and in the second section 20c, a plurality of UV lamps 15 and rod sonotrodes are respectively arranged as treatment elements, which extend in the direction of the respective section. The UV lamps are preferably configured to fully illuminate the first and second sections, respectively.

The first section has, in a first zone in the region of the inlet 11, a first type of rod sonotrodes 16a; in the figure lb this first zone is indicated by the reference numeral 21. In a second zone (indicated in the figure by the reference numeral 22) which adjoins (or merges with) the turning zone 20b, the first section 20a of the treatment channel has a second type of rod sonotrodes 16b; the rod sonotrodes of the first and second types extend in the direction of the first portion only over a portion which is smaller than half the length of the first portion, in the example shown about two-fifths of its length (or height). Finally, in the second section 20c, rod sonotrodes 16c of a third type are arranged; this third region is identified by the reference numeral 23 in FIG. 1b and these rod sonotrodes extend for substantially the full length of the second section.

The individual types of Stabsonotroden differ in particular in a frequency of ultrasound, they emit each. Each of the three regions preferably has a plurality of stab sonotrodes 16a, 16b and 16c, respectively, which are connected to different ultrasonic generators (not shown). This avoids an in-phase oscillation of the rod sonotrodes in the individual regions.

According to an exemplary advantageous embodiment, the rod sonotrodes 16a of the first type are arranged to generate frequencies of 20-30 kHz, the rod sonotrodes 16b of the second type generate an ultrasonic field with frequencies of 30-50 kHz and the rod sonotrodes 16c of the third type to generate an ultrasonic field with frequencies of 50 - 100 kHz. In this way, successive different forms of cavitation in the treatment channel can be generated, which in each case damage the various microorganisms contained in the contaminated water. In Figure lb the course of the treatment channel from the inlet 11 to the outlet 12 through the reactor 10 is illustrated. The reactor is thereby oriented vertically, wherein the inlet 11 and the outlet 12 are arranged in a vertically upper region. The individual zones thus allow an advantageous exposure time during which the organisms are exposed to the combination of UV radiation (preferably UV-C radiation) and the ultrasound field within the respective areas. In particular, the exposure time can be controlled, for example, by a pulsed introduction of contaminated water, because the water is displaced from the reactor only by water flowing in.

According to a specific embodiment, the exposure time in the reactor is a maximum of 10 seconds, preferably in each case between a minimum of 1 second and a maximum of 3 seconds in each of the zones 21, 22 and 23.

The introduced contaminated water is thereby divided by means of a flow divider into two parallel (in the direction of the figure lb one behind the other) partial flows, each helically winding in along the treatment channel around the treatment elements, as illustrated by the arrows in the figure; the division and deflection into such turns is illustrated in FIG. 2:

2 shows a cross section through the reactor 10. As can be seen in the illustration, each of the (separated by the partition wall 14) sections 20a and 20c of the treatment channel each three UV lamps 15 (in cladding) on. In the area shown, three rod sonotrodes 16a, 16c are also arranged in each of the sections; As indicated by the different boundaries, other types of rod sonotrodes are arranged in the first section 20a than in the second section. In the representation perspective of FIG. 2, it is not possible to see in the first section 20a in an area lying further behind in the viewing direction another three rod sonotrodes (which are designated by reference numeral 16b in FIG. 1a).

The arrows illustrate in the figure how charged water flowing in through the inlet 11 into the reactor 10 impinges on a rod sonotrode 16a 'located substantially in a plane E bisecting an opening of the inlet; in the illustration of Figure 2, the plane E is orthogonal to the plane of representation and is given as such by the horizontal. The Stabsonotrode 16a 'thus acts as a flow divider element, which - as indicated by the arrows - divides the introduced water flow into two partial streams. Each of the partial flows is deflected several times by the partition and then by an outer wall of the reactor, so that the strained water winds around the UV lamps 15 around; in the course of the treatment channel, this results in a helical flow up to the turning region of the treatment channel. From there, the contaminated water enters the second section, in which it is preferably again guided in two partial streams and by multiple deflections around the UV lamps 15 and to the outlet. In this way, the contaminated water can be effectively and controlled exposed to the treatment elements in the treatment channel, which allows its particularly efficient and targeted treatment.

A reactor 10 according to the invention serves to clean contaminated water. It has a treatment channel with a first section 20a and a second section 20c extending parallel thereto and with a turning section 20b lying between the first and the second section. The first portion 20a has an inlet 11 directed to at least one flow divider 16a 'extending in the direction of the first portion.

A method according to the invention for purifying polluted water in a reactor comprises introducing and passing the polluted water through a first section 20a, through a turning section 20b and through a second section 20c of a treatment channel, whereby the loaded water is divided into at least two substreams that flow through the first portion 20a side by side.

LIST OF REFERENCE NUMBERS

10 reactor

11 inlet

12 outlet

13 Connecting pieces for UV sensors

14 partition wall

15 UV lamp

16a, 16b, 16c Stabsonotrode

16a 'Stabsonotrode as Stromteilungselement

17a cover surface

17b floor space

18 lateral surface

19 passage

20a first section of the treatment channel

20b turning region of the treatment channel 20c second section of the treatment channel

21 first area

22 second area

23 third area

E opening of the inlet halving level

H height of the reactor

Claims

P atentansprü che reactor and process for the treatment of contaminated water

A reactor (10) for cleaning contaminated water comprising a treatment channel having a first section (20a) and a second section (20c) extending parallel thereto and a turning section (20b) lying between the first and second sections,

wherein the first portion has an inlet (11) directed towards at least one flow divider (16a ') extending in the direction of the first portion.

2. Reactor according to claim 1, wherein the at least one flow divider element (16a ') as a treatment element, in particular as an ultrasonic Stabsonotrode (16a) and / or a UV lamp is formed.

3. A reactor according to any one of claims 1 or 2, wherein the reactor is substantially circular cylindrical or a straight prism having a substantially regular polygon shaped base, and wherein the inlet (11) is oriented orthogonal to a height (H) of the reactor is.

4. Reactor according to one of the preceding claims, wherein the flow dividing element (16a ') is located substantially in a plane (E) which halves an opening of the inlet (11).

A reactor according to any one of the preceding claims wherein the reactor is substantially circular cylindrical or a straight prism and the first and second portions are separated from one another by a dividing wall (14) extending along a central axis of the reactor.

6. A method of purifying contaminated water in a reactor (10) comprising introducing the contaminated water into a first section (20a) of a treatment channel in the reactor

and passing the contaminated water through the first section in succession, through a turning region (20b) of the treatment channel and through a second section (20c) of the treatment channel extending parallel to the first section,

wherein the loaded water is divided into at least two partial streams, which flow through the first section at least partially adjacent to each other.

A method according to claim 6, wherein the splitting is performed by impingement of an introduced ballast water flow on at least one flow splitting element (16a ') extending in the direction of the first section.

8. The method according to claim 7, wherein the flow divider element comprises at least one treatment element, in particular an ultrasonic Stabsonotrode (16a) and / or a UV lamp.

9. The method according to any one of claims 6 to 8, wherein the reactor is formed substantially circular cylindrical or as a straight prism with a substantially regular polygon shaped base surface, and wherein the introduction is orthogonal to a height (H) of the reactor.

10. The method according to any one of claims 6 to 9, wherein the treatment channel when passing the ballast water in the first section (20a) of an inlet

(11) extends substantially vertically down to the turning region (20b) and substantially vertically upward in the second section from the turning region to an outlet (12).