NO344502B1

NO344502B1 - Bioreaktor

Info

Publication number: NO344502B1
Application number: NO20170340A
Authority: NO
Inventors: Knut Vangen; Vidar Vangen
Original assignee: Knut Vangen; Vidar Vangen
Priority date: 2017-03-08
Filing date: 2017-03-08
Publication date: 2020-01-20
Also published as: WO2018163096A1; NO20170340A1

Description

TITLE:

[1] Bioreactor

THE FIELD OF THE INVENTION

[2] The present invention relates to a purifying bioreactor comprising:

a pump;

a flow director;

one or more branch pipes;

an intake filter;

a center pipe; and

a biosubstrate.

[3] The present invention also relates to a use of a water purifying bioreactor.

[4] The present invention further relates to a method cleaning a fish pen with a purifying bioreactor.

[5] The present invention also relates to a fish pen cleaning system.

[6] The present invention relates to a purifying bioreactor, particularly for the filtering and cleaning of water, more particularly for filtering and cleaning water in a fish pen. Associated systems, uses, and methods are also presented.

BACKGROUND

[7] Fish farming is a very important source of food. It supplies a great deal of consumed fish in the world. It is easier and more controllable when compared to harvesting wild fish through commercial fishing. While the main focus of this invention is upon fish farming, the same invention could be used on other aquatic animals such as mollusks and crustaceans.

[8] Fish farming can be performed in both fresh and salt water. One technique is to build a fish pen in the body of water itself. A fish pen can be open to the surrounding water by using netting that is too small for fish to escape from, or closed off from the surrounding water through the use of a material that the fish cannot swim through. A closed fish cage has less impact on the environment because any harmful materials or chemicals are contained in the system. It is also common for a fish pen to be built on land.

[9] Bioreactors use biosubstrates to remove chemicals and bacteria from water by a biological process. The biosubstrate can be an organism or other organically active material. They are used to remove different chemicals at different efficiencies. A bioreactor can be used on both still water and running water.

[10] Bioreactors have been used in both aquariums and fish pens on shore. They are located outside of the body of water, usually on land, and pump clean water into the fish pen system. Examples of bioreactors can be found in US8877045B1, US20130105408A1, WO8809615A1 and NO324084B1.

TECHNICAL PROBLEM TO BE SOLVED

[11] There is a need for an efficient and economic way to both increase the yield and quality of the harvested fish.

[12] Each breed of fish has an ideal temperature in which it can thrive. This is often warmer than the surrounding water. This can be particularly true in salt water fish pens where the water can be quite cold. However, if the temperature is too high, the meat may not have the best quality. If the temperature is too cold, the yield may be lower. Heating water requires a significant amount of energy. This energy corresponds to a higher operating cost.

[13] Another of the factors that affect the quality of the meat is how active the fish are. When the fish are allowed to simply sit in one place and rest, the fish meat may be too fatty and the overall quality is lowered. To combat this, many fish pens generate a water current so that the fish must swim and remain active.

[14] In addition to controlling the physical conditions of the fish pen to improve yield and quality of the fish, keeping the fish pen clean is also critical. One of the things that must be done is to remove sediment and other physical matter that can fall to the bottom of the fish pen. Examples of this sediment can include feces, dead fish, uneaten feed.

[15] Removing excess protein from the fish pen, usually through skimming, is also important. It can lower the amount of bacteria and pathogens and increase the amount of oxygen in the water. As such, the fish will have fewer infections.

[16] The production of fish in a fish farm requires the control of different amounts of chemicals. In particular, it is important to control of ammonia and nitrite levels. This is often done using different strains of bacteria or phosphate fertilizers.

SHORT SUMMARY OF THE INVENTION

[17] Thus the purifying bioreactor is described by:

the center pipe is arranged inside the bioreactor roughly along the entire length of the longitudinal axis of said bioreactor;

the pump is arranged inside of and toward the bottom of the center pipe;

the one or more branch pipes are connected to the center pipe and extend outwards from the center pipe to the outside of the bioreactor

the flow director is located inside of the center pipe and is arranged between the pump and the lowest of the lowest of least one branch pipes;

the pump directs water through the intake filter at the bottom of the bioreactor and directs it to the flow director which directs the water at an angle with respect to the longitudinal axis of the center pipe through the biosubstrate.

[18] In accordance with the first aspect of the purifying bioreactor, one or more branch pipes are distributed at approximately equal angles to each other when measured on a transverse plane.

[19] In accordance with the second aspect of the purifying bioreactor, the one or more branch pipes are disposed at different heights along the center pipe.

[20] In accordance with the third aspect of the purifying bioreactor, the one or more branch pipes comprise:

a pipe exit on the end that is away from the center pipe; wherein the angle of the pipe exit with respect to the tangent line of the surface of the bioreactor, can be any angle less than 90º, with preferable between 0º and 45º, most preferably of between 0º and 30º.

[21] In accordance with the fourth aspect of the purifying bioreactor, the biosubstrate travels with the water current inside the bioreactor.

[22] In accordance with the fifth aspect of the purifying bioreactor, the bioreactor has an upper filter at the top of the center pipe.

[23] In accordance with the sixth aspect of the purifying bioreactor, the bioreactor further comprises a scum trap and a scum skimmer above the upper filter.

[24] In accordance with the seventh aspect of the purifying bioreactor, it further comprises one or more radially distributed partitions inside the bioreactor.

[25] In accordance with the eight aspect of the purifying bioreactor, it further comprises a removal anchor, and a mounting plate, wherein the pump and the flow director are both mounted to the mounting plate, and the removal anchor is arranged at the top of the mounting plate.

[26] Thus the use of the present invention is for creating a circular current in the water in a fish pen due to the angle of the pipe exits.

[27] In accordance with the first use of the present invention for cleaning a the water in fish pen by placing the bioreactor in the middle of the fish pen.

[28] In accordance with the second use of the present invention for creating a circular current in a fish pen due to the angle of the pipe exits.

[29] In accordance with the third use of the present invention for harvesting fish in a fish pen without removing the bioreactor from the fish by:

lifting the lifting plate using the removal anchor; and

forcing fish up the now open center pipe.

[30] Thus the method of the present invention is described by the steps in the following order of:

(a) pumping water from the bottom of the purifying bioreactor toward the top;

(b) directing the water using the flow director into the biosubstrate; the water is then

(c) flowing to the top of the bioreactor; then

(d) entering into the center pipe; and further

(e) flowing out the one or more branch pipes; and further

(f) flowing out the pipe exist into the fish pen; and thereby

(g) generating circular water current flow in the fish pen in one or more dimensions.

[31] In accordance with the first aspect of the method in that step (f) further comprises flowing out of the pipe exits which have been arranged to generate a circular current in the fish pen.

[32] Thus the fish pen cleaning system of the present invention is described by the following: a purifying bioreactor in accordance with the present invention; and a fish pen.

[33] In accordance with the first aspect of the system of the present invention the fish pen is made from a waterproof fabric.

ADVANTAGES OF THE PRESENT INVENTION

[34] The present invention has several advantages over previous solutions to the technical problems discussed previously. Using a bioreactor that has been placed directly in the fish pen leads to several improvements over previous inventions. The present invention places a bioreactor directly in the water in the fish pen that has been modified to generate a water current in the fish pen.

[35] By placing the bioreactor directly into the fish pen, there is much less heat loss when compared to using a bioreactor that is not in the fish pen. Since the present invention generates a water current, the fish are forced to swim; without the need for extra equipment. The present invention requires less water because there is less water loss in recirculation.

[36] The operation of the bioreactor removes carbon dioxide and adds oxygen. The protein in the water will then float due to the gas bubbles that are generated. It is a simple matter to remove the protein with a scum skimmer.

[37] The water current will move the sediment, and other matter, to the edge of the fish pen. During typical operation the bioreactor will generate circular currents in more than a single plane. These currents will help the sediment slide down the side of the fish pen. This is much more efficient than simply waiting for the matter to sink down to the bottom of the fish pen.

BRIEF DESCRIPTION OF THE FIGURES

[38] FIG 1 discloses a perspective view of an embodiment of a fish pen system.

[39] FIG 2 discloses a side view of an embodiment of a fish pen system.

[40] FIG 3A discloses a cross sectional view of an embodiment of the purifying bioreactor.

[41] FIG 3B discloses a cross sectional view of an alternate embodiment of the upper part of the circulation system of the purifying bioreactor.

[42] FIG 3C discloses a front view of an alternate embodiment of the top part of the circulation system of the purifying bioreactor.

[43] FIG 3D discloses a cross sectional view of an alternate embodiment of the top part of the circulation system of the purifying bioreactor.

[44] FIG 4 discloses a cross sectional view of an embodiment of the pipe system

[45] FIG 5 discloses a front view of an embodiment of the pipe system.

[46] FIG 6A discloses a top view of an embodiment the purifying bioreactor.

[47] FIG 6B discloses a perspective view of an embodiment of the partitioning in the purifying bioreactor.

[48] FIG 7 discloses a transverse slice through the branch pipe of the purifying bioreactor.

[49] FIG 8 discloses a top view of an embodiment of the purifying bioreactor.

[50] FIG 9 discloses a top view of an embodiment of a fish pen system.

LIST OF USED REFERENCE NUMERALS:

[51] 10 Bioreactor

[52] 11 Bioreactor Housing

[53] 12 Float

[54] 13 Intake Filter

[55] 14 Hatch

[56] 15 Tank Cover

[57] 20 Circulation System [58] 21 Center Pipe

[59] 211 Center Pipe Cover [60] 212 Inner Pipe Cover [61] 2121 Inner Pipe Cover Filter [62] 213 Outer Pipe Cover Filter [63] 22 Pump

[64] 23 Pump Filter

[65] 24 Flow Director

[66] 25 Branch Pipe

[67] 251 Pipe Exit

[68] 26 Removal Anchor [69] 27 Partition

[70] 28 Upper Filter

[71] 281 Retaining Filter

[72] 29 Mounting Plate

[73] 30 Fish Pen System

[74] 31 Pen Boundary

[75] 37 Pen Edge

[76] 33 Column Grate

[77] 34 Bridge

[78] 40 Biosubstrate

[79] 41 Scum

[80] 42 Scum Skimmer

[81] 43 Scum Trap DETAILED DESCRIPTION OF THE INVENTION

[82] Using the attached drawings, the technical contents, and detailed descriptions, the present invention is described. Alternate embodiments will also be presented. In summary: the present invention relates to a specially adapted bioreactor. Water is brought in from the bottom of the bioreactor by a pump. The water is directed through a biosubstrate. As the water travels through the bioreactor system, waste chemicals are removed and at the same time protein scum is removed from the water. This water exits the bioreactor through branch pipes. The pipes are at an angle with respect to the bioreactor housing. This angle facilitates the generation of a circular current flow of water around the outside of the bioreactor. This bioreactor can be used inside a fish pen. The invention is described in further detail below. Included are alternate embodiments. One skilled in the art can adapt many of these embodiments without undue burden.

[83] Reference is made to FIG 1. This figure discloses a perspective view of an embodiment of a fish pen system. In this embodiment the bioreactor 10 is located in the approximately the middle of a fish pen 30. The bioreactor comprises a cylindrical housing 11 that has a float 12 on the upper portion. This float aids the bioreactor in keeping the proper position in the water. A bottom filter 13 safely prevents fish from the fish pen 30 to enter the bioreactor when it is under operation. A tank cover 15 rests on the float 12. Under the tank cover 15 are elements that are associated with scum 41 (not shown) removal. A series of pipe exits 251 allows the water to flow out of the bioreactor 10. The inner elements of the bioreactor will be first disclosed in FIG 3A.

[84] The fish pen 30 shown in FIG 1 is provided as an illustrative example. The pen edge 37 is the top of the fish pen 30. From the pen edge 37 connects to the pen boundary 31. Water and fish are located inside the pen boundary 31. A column grate 33 has openings large enough for the fish to travel through and aids in harvesting the fish.

[85] While the bioreactor 10 is shown as cylindrical, this is not the only acceptable shape. The important thing is not the shape, but that water can enter the bioreactor 10 and exit through the pipe exits 251. One skilled in the art can adapt the inner elements (discussed shortly) to fit the task. The shape of the shape of the fish pen 30 can easily be adjusted to fit the requirements of the task by one skilled in the art. It is preferable the fish pen 30 is of limited permeability for the best circular current effect.

[86] The pipe exits 251 are shown in the preferred embodiment. They are positioned at a tangential angle to the bioreactor housing 11. This will provide good circular water current generation. To generate the circular current. However the generation of circular water currents is not a requirement of the bioreactor 10. It can easily be operated without any special angle between the bioreactor housing 11 and the pipe exit 251. This can be an advantage if the body of water to be filtered does not require any circular currents. It can also be an advantage is the pen boundary 31 is netting and only needs cleaning. The pipe exits 251 could be arranged such that they could attain different angles while the bioreactor 10 was in operation.

[87] While FIG 1 shows a float 12, this is simply a means to keep the bioreactor at the proper height with respect to the surface of the water. This could be done by physical or mechanical means as well. For example a crane that keeps the bioreactor 10 at the right depth.

[88] The bottom filter 13 is to keep the fish out. It also severs the role of preventing any large particles from entering the bioreactor 10. Depending on the needs of the system, this should be a fine mesh screen, a large mesh screen, a grating, etc. If a maximum circulation of water is desired, this could be as large as possible to not let fish into the bioreactor 10. If however, the bioreactor was simply used to effectively filter water inside of a fish pen 30 that did not contain fish, then a bottom filter 13 would not be necessary.

[89] Reference is made to FIG 2. This figure discloses a side view of an embodiment of a fish pen 30. The bioreactor 10 is located in the middle of the fish pen 30. The exterior of the bioreactor 10 is the same as shown in the previous figures. The tank cover 15 is on top of the main bioreactor housing 11. The intake filter 13 is located on the bottom of the bioreactor 10.

[90] The fish pen 30 is shown with the pen edge 37 and the fish boundary 31. The longitudinal axis of both the fish pen 30 and the bioreactor 10 runs through the s of each of these.

[91] Reference is made to FIG 3A. This figure discloses a cross sectional view of an embodiment of the purifying bioreactor. The internal elements of an embodiment of the bioreactor 10 are shown. Water to be filtered is brought into the bioreactor 10 through the intake filter 13. This water is drawn into the bioreactor 10 by the pump 22. The water current formed by the pump 22 is then deflected by the flow director 24 into the inner body of the bioreactor 10. The water travels through a biosubstrate 40. The biosubstrate helps to remove unwanted chemicals from the water. Note that system is arranged such that the biosubstrate 40 is entirely or primarily retained inside the bioreactor 10 during operation. The water then passes upwards through the body of the bioreactor 10. There are many kinds of biosubstrate that can be used depending on the operating conditions and the chemicals that are to be filtered. One embodiment on the invention uses KMT as a biosubstrate.

[92] When the water reaches high enough, it falls into the longitudinally (vertically) arranged center pipe 21, into the branch pipes 25, and out through the pipe exits 251. The branch pipes 25 extend radially out from the center pipe 21.

Additionally an upper filter 28 is arranged such that scum 41, primarily from proteins in the water, floats up and is trapped on its surface. This scum 41 will be moved into a scum trap 43 during the bioreactor’s 10 operation. The tank cover 15 covers the top of the bioreactor 10. The bioreactor is fully or partially held at the correct depth by use of the float 12. The intake filter 13 has a hatch 14 to aid maintenance and the harvesting of fish.

[93] The circulation system 20 refers to the parts that are inside the bioreactor 10 that are for the primary motion of the water inside the bioreactor 10. It is comprised of: a center pipe 21, pump 22, pump filter 23, flow director 24, branch pipe 25, with a pipe exit 251. This will be disclosed in further detail in FIG 4 and FIG 5.

[94] While in the preferred embodiment, the biosubstrate 40 is not stationary and travels along with the water stream. This maximizes the possible contact area between the biosubstrate and the water that needs treated. Different choices of substrates will effect which chemicals are removed from the water. This will easily be found by one skilled in the art. The pH and chemical composition of water is well known in the art. To minimize the amount of biosubstrate 40 that enters into the fish pen, a retaining filter 281 can be used. This is a filter that is small enough to prevent the biosubstrate 40 particles from leaving the bioreactor. Other embodiments may include different types of retaining filters 281, screens that also serve for particulate or protein filtering, or not have one at all.

[95] As mentioned previously, the type of filter used can be adjusted depending on the operating conditions and available materials. Normally these will be screens of different opening sizes.

[96] The top portion of the circulation system 20 can serve a number of purposes. The arrangement of screens and filters will influence how easy it is for gas to vent from the system, protein to bubble up in the system, and how pure the water is that enters the center pipe 21. If desired, it is also possible for the top portion of the circulation system 20 to be arranged such that little biosubstrate 40 can enter the center pipe 21. The exact configuration can be determined by one skilled in the art. The main requirement of the top of the circulation system 20 is that water that has been cleaned inside the bioreactor 10 can exit through the center pipe 21.

[97] FIG 3A is shown with four (two on the left and right, one on the front and back) branch pipes 25. They are also shown as perpendicular to the branch pipe 25. This is not a requirement for operation of the bioreactor 10. It is the configuration that will use the short lengths of branch pipes 25. This angle between the branch pipe 25 and the center pipe 21 could be changed in order to change the angle at which the water exits the bioreactor 10. Changing the number of branch pipes 25 would also not change the function of the bioreactor. Depending on the needs, a single branch pipe 25 could be enough; where in others more than four could be needed. This will be dependent upon the amount and placement of pipe exits 25 that are needed.

[98] Additionally FIG 3A shows that the branch pipes 25 exit in a straight line radially outwards from the center pipe 21. While this is the preferred configuration, it is also possible for the branch pipes 25 to have an elbow in them. This may be required to work around internal elements in the bioreactor 10. It could also be to take water from different points in the center pipe 21 and distribute them at different a different point in the bioreactor 10. The branch pipes 25 are all shown at different heights on the center pipe 21, but this not required. There will be no loss of functionality.

[99] The speed of the water through the bioreactor 10 will be controlled by a number of factors including the sizes of various filters. It is also dependent upon the strength of the pump 22. This will be adjusted by one skilled in the art for the desired rate of output and the contact time between the water and the biosubstrate 40. If needed for flow rate or strength, more than one pump could be used. It is foreseeable that one pump 22 would pull water into the bioreactor 10 and a second pump 22 would be located after the pump filter 23 to improve flow within the bioreactor itself 10. It could be advantageous to have a pump 22 arranged inside of the center pipe 21 to increase the force of the output current. The pump(s) 22 can be operated in both a continuous, regular pulsing, or in an intermittent manner.

[100] It would be possible to either separate the center pipe 21 or replace it with more than one pipe. In that situation it would be possible to have a different branch pipe 25 taking water from a different portion of the “center pipe” 21.

[101] The flow director 24 is shown such that it is arranged such that the water stream is directed off of it at a 45 degree angle. This is not a required angle. The purpose of this is to allow for a vertically aligned pump to move the water into the biosubstrate 40 rather than going up into the bottom of the central pipe 21. If the pump was at an angle, this flow director 24 may not be necessary.

[102] Reference is made to FIGs 3B – 3D. These figures disclose different views of the preferred embodiment of the top portion of the circulation system 20. In this embodiment, the top center pipe 21 is enclosed in a number of other structures. Water from the bioreactor 10 passes through the upper filter 28. His upper filter 28 helps to keep the bio substrate 40 (not shown) inside the bioreactor 10. This water will then pass through the outer pipe cover filled 213 and into the inner pipe cover filter 2121. The water then flows down into the inner pipe cover 212 up into the center pipe cover 211 and falls into the center pipe 21. As before protein will be removed from the upper filter 28 and into the scum trap 43. A spray nozzle 45 will help prevent protein scum from building up onto the inner pipe cover filter 213 or the inner pipe cover filter 2121. An Injector 44 is used to add new water to the bioreactor 10. This water can help the filtering process by adding bubbles to the water and by increasing the rate of motion inside of the bioreactor 10.

[103] Reference is made to FIG 4 and FIG 5. These figures disclose a cross sectional view of an embodiment of the circulation system 20. The main function of this system is the control the active flow of water through into and out of the bioreactor 10. A pump 22 is located at the bottom of the center pipe 21. A flow director 24 forces the water through the pump filter 23 to enter the main body of the bio reactor 10, rather than simply traveling up into the center pipe 21. The pump filter is located on the center pipe 21. Eventually water will reach high enough and fall back into the center pipe 21. During the fall, the water will travel through the branch pipes 25, pass through the bioreactor housing 11, and leave the bioreactor through the pipe exits 251.

[104] To aid in the harvesting of fish, the pump 22, flow director 24 can be pulled out of the center pipe 21 by use of a removal anchor 26. For this to be achieved, the pump 22 and the flow director 24 are both mounted to a plate or pipe of some kind. The removal anchor 26 is attached to the mounting plate 29. In this way, the pump 22 and the flow director 24 could both be pulled out of the center pipe 21. That would allow for fish to be harvested without the need to remove the bioreactor 10 from the fish pen 30. The hatch 14 (shown in FIG 3A) would be opened to aid in this process.

[105] Reference is made to FIGs 6A and 6B. These figures disclose an embodiment of the partitions 27 in the purifying bioreactor 10. In this embodiment, partitions 27 have been inserted inside of the bioreactor 10. This divides up the inner space of the bioreactor 10 into several sections. This can serve the function of increasing the contact time that the water that is in contact with the biosubstrate 40 in the narrower space. As seen form this figure, the radius of the center pipe 21 is only a small portion of the total radius of the bioreactor 10. The branch pipes 25 are within the water that is inside the bioreactor 10. They do not serve as a partition 27 in a large capacity. The pipe exits 251 direct the water in a way that generates a circular current in the fish pen 30.

[106] The partitions 27 extend almost the full length of the bioreactor 10. The first partition 27 shown in FIG 6B has a gap at the top between the partition 27 and the upper filter 28. The gaps of the partitions 27 alternate between the top and the bottom. In an embodiment of the present invention, the gaps are about a sixth of the height of the bioreactor. In another embodiment, they are approximately 30cm. Also, the width of the partition 27 can extend from the center pipe 21 to the bioreactor housing 11. In another embodiment, the width of the partition can be such that a gap is left between the partition 27 and the bioreactor housing 11. In one embodiment there is no gap between the partition 27 and the bioreactor housing 11, in another the gap is 10cm, and in another embodiment the gap is a sixth of the radius of the bioreactor. The dimensions, both height and width, of the partitions 27 are arranged such to give the required amount of contact time of the water and contact surface area. The larger the gaps, the less resistance to the water flow are obtained, but correspondingly a reduction in how long the water spends inside the bioreactor 10.

[107] As disclosed previously, the flow director 24 (not shown) directs the water at an angle with respect to the longitudinal axis of the center pipe 21. This causes a circular current inside of the bioreactor 10 makes the water flow in a uniform direction. During operation, the water will tend to flow from one partition to another, due to the water current. The partition 27 that is closest to where the water enters the bioreactor 10 will usually be the one with the most impurities. It will then travel up and either over into the next partition or into the center pipe 21. This will continue as the water travels up and over subsequent partitions. The water in each partition 27 will be cleaner than the one before it due to longer overall contact time with the biosubstrate 40. Water that is in the first partition 27 will be less filtered than that in the next one.

[108] Even through the figure is shown with 4 partitions at right angles to each other this is not required. On skilled in the art would easily be able to add or subtract partitions to meet the needs of the task. Normally, the partitions 27 would be at equal angles to each other. This becomes more complicated to describe the angle between the partitions 27 when it is curved in any dimension. It may be desirable to have a curved partition 27 to aid in the flow of water.

[109] It would be possible to attach a partition 27 directly to a branch pipe 25. In this way, it would help lend support to the branch pipe 25.

[110] Reference is made to FIG 7. This figure discloses a transverse slice through the branch pipe 25 of the purifying bioreactor 10. Each of branch pipes is shown with its longitudinal axis perpendicular to the center pipe’s 21 longitudinal axis. Each branch pipe 25 extends from the center pipe 21 through the bioreactor housing 11. The pipe exit 251 is at an angle with respect to the longitudinal axis of the branch pipe 25 and the longitudinal axis of the pipe exit 251.

[111] This angle has been shown in several figures as a 90º angle. The main purpose of this angle is to generate a circular current in the water around the bioreactor 10. Technically that means any angle less than 90º. For an angle that is exactly 90º, there would be no force in a direction that would generate a circular current. In practical terms it will dictated by the conditions of the task. However, an angle of between 89º and 45º would be efficient, and with between 89º and 60º being better, for generation of a circular current.

[112] This angle is perhaps more convenient when measured with respect to the line tangential to the surface of the bioreactor 10. The angle of the pipe exit 251 with respect to the tangent can be any angle less than 90º, with an angle of between 0º and 45º being more efficient, and between 0º and 30º

[113] Reference is made to FIG 8. This figure discloses a top view of an embodiment of the purifying bioreactor. Bridges 34 connect the bioreactor 10 to the rest of the fish pen 30. Partitions 27 are under the upper filter 28. The upper filter 28 will help to trap the scum 41 (not shown), from the water. This scum 41 is scraped off using a scum skimmer 42 and into a scum trap 43. The scum removal can be carried out or adapted from standard techniques by one skilled in the art. The bioreactor is kept at the right depth with the aid of a float 12.

[114] Reference is made to FIG 9. This figure discloses a top view of an embodiment of a fish pen 30 system. In this standard arrangement, the bioreactor 10 is located within the center of the circle defined by the pen edges 37. A float 12 helps to hold the bioreactor 10 at the correct depth. Bridges 34 extend from the pen edges 37 to the bioreactor. These bridges 34 allow axis and provide some degree of lateral support for the bioreactor.

[115] By circular current flow, it is meant in a plane that is level with the surface of the water. Note that even though the currents are being viewed from the top of the bioreactor, it is in a system that has depth. Because of this, the currents can also have a depth component. Circular does not refer to a perfect circle. This can be thought of as the pipe exits 251 create a rotation of the water in the fish pen. It is not the exact angle and shape of that rotation that is important.

[116] The bioreactor 10 is shown in the FIG 1, FIG 2, and FIG9 as being in the middle of the fish pen 30. While this is the preferred embodiment, it is not the only embodiment. It is governed in part by the shape of the fish pen 30. The one that has been shown has been parabolic and the most efficient way would be to have both the bioreactor 10 and the fish pen 30 on the same longitudinal axis. However if the shape of the fish pen 30 and/or the bioreactor 10 changed, or the operational requirements demanded; one skilled in the art would have no problem moving the bioreactor 10 as needed. There is no functional limitation on the position.

[117] Different materials and shapes of the pen boundary 31 can improve the sedimentation process. Shapes materials and shapes that make it easier for the sediments to slide down could make a difference in the efficiency of the sedimentation portion of the purification process.

[118] Even though the bioreactor 10 was mainly designed to be used in a fish pen 30, there is no reason that it would not function equally well in other enclosed bodies of water.

[119] Also, the invention is preferably used in a fish pen that is in the water. It could also be placed on land.

[120] A specific and non-limiting example of a set of operating conditions is given below. Using KMT as the biosubstrate, 1 m<3>can be used for 15 kg of feed each day. A reacting/contact time of 4 minutes is sufficient in this case. One skilled in the art could experiment with the level of feed, biosubstrate, and contact time to satisfy the needed operating conditions.

[121] Note that it will be possible, and often desirable, to generate circular currents in more than one dimension during operation. An example of this could be a current that is clockwise with the longitudinal axis of the fish pen and a current that is rolling from shallower to deeper water in the tank.

[122] Please note that “step of” is not to be interpreted as “step for”. By “comprised of”, “comprising”, “comprises” etc. it is referring to an open set and by “consisting of” it is referring to a closed set.

Claims

1. A purifying bioreactor (10) comprising:

a pump (22), a flow director (24), one or more branch pipes (25), an intake filter (13), a center pipe (21); and a biosubstrate (40);

CHARACTERIZED in that:

the center pipe (21) is arranged inside the bioreactor (10) roughly along the entire length of the longitudinal axis of said bioreactor (10);

the pump (20) is arranged inside of and toward the bottom of the center pipe (21);

the one or more branch pipes (25) are connected to the center pipe (21) and extend outwards from the center pipe (21) to the outside of the bioreactor (10)

the flow director (24) is located inside of the center pipe and is arranged between the pump and the lowest of the lowest of least one branch (25) pipes;

the pump draws water through the intake filter (13) at the bottom of the bioreactor (10) and directs it to the flow director (24) which directs the water at an angle with respect to the longitudinal axis of the center pipe (21) through the biosubstrate (40).

2. A water purifying bioreactor (10) in accordance with claim 1, CHARACTERIZED in that one or more branch pipes (25) are distributed at approximately equal angles to each other when measured on a transverse plane.

3. A water purifying bioreactor (10) in accordance with claim 1 or 2,

CHARACTERIZED in that the one or more branch pipes (25) are disposed at different heights along the center pipe (21).

4. A water purifying (10) bioreactor in accordance with any of claims 1 to 3,

CHARACTERIZED in that the one or more branch pipes (25) comprising:

a pipe exit on the end that is away from the center pipe (21); wherein the angle of the pipe exit (251) with respect to the tangent line of the surface of the bioreactor (10), can be any angle less than 90º, with preferable between 0º and 45º, most preferably of between 0º and 30º.

5. A water purifying bioreactor (10) in accordance with any of the proceeding claims, CHARACTERIZED in that the biosubstrate (40) travels with the water current inside the bioreactor (10).

6. A water purifying bioreactor (10) in accordance with any of the proceeding claims, CHARACTERIZED in that the bioreactor (10) has an upper filter (28) at the top of the center pipe (21).

7. A water purifying bioreactor (10) in accordance with any of the proceeding claims, CHARACTERIZED in that the bioreactor (10) further comprises a scum trap (43) and a scum skimmer (42) above the upper filter (28).

8. A water purifying bioreactor (10) in accordance with any of the proceeding claims, CHARACTERIZED in that it further comprises one or more radially distributed partitions (27) inside the bioreactor (10).

9. A water purifying bioreactor (10) in accordance with any of the proceeding claims, CHARACTERIZED in that it further comprises a removal anchor (26), and a mounting plate, wherein the pump (22) and the flow director (24) are both mounted to the mounting plate (29), and the removal anchor (26) is arranged at the top of the mounting plate (29).

10. Use of a water purifying bioreactor (10) in accordance with any of claims 1-9 for cleaning the water in a fish pen (30) by placing the bioreactor in the middle of the fish pen (30).

11. Use of a water purifying bioreactor (10) in accordance with any of claims 1-9 for creating a circular current in a fish pen (20) due to the angle of the pipe exits (251).

12. Use of a water purifying bioreactor (10) in accordance with claim 9 for harvesting fish in a fish pen without removing the bioreactor (10) from the fish pen (30) by: lifting the lifting plate (29), using the removal anchor; and forcing fish up the center pipe (21).

13. A method for cleaning the water in a fish pen (20) with a purifying bioreactor (10) in accordance with any of claims 1-9, CHARACTERIZED by comprising the steps in the following order of:

(a) pumping water from the bottom of the purifying bioreactor (10) toward the top;

(b) directing the water using the flow director into the biosubstrate (40); the water is then

(c) flowing to the top of the bioreactor (40); then

(d) entering into the center pipe (21); and further

(e) flowing out the one or more branch pipes (25); and further

(f) flowing out the pipe exist (251) into the fish pen (30); and thereby

(g) generating circular water current flow in the fish pen (30) in one or more dimensions.

14. A method for cleaning a fish pen with a purifying bioreactor (10) in accordance with claim 13, CHARACTERIZED in that step (f) further comprises flowing out of the pipe exits (251) which have been arranged to generate a circular current in the fish pen (30).

15. A fish pen cleaning system CHARACTERIZED in that it comprises:

a purifying bioreactor (10) in accordance with any of claims 1-9; and a fish pen (30).

16. A fish pen cleaning system in accordance with the previous claim CHARACTERIZED in that the fish pen (30) comprises a pen boundary (31) that is made from a waterproof fabric.