US3875052A - Process for separating microscopic algae - Google Patents
Process for separating microscopic algae Download PDFInfo
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- US3875052A US3875052A US274252A US27425272A US3875052A US 3875052 A US3875052 A US 3875052A US 274252 A US274252 A US 274252A US 27425272 A US27425272 A US 27425272A US 3875052 A US3875052 A US 3875052A
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- 238000000034 method Methods 0.000 title claims abstract description 75
- 241000195493 Cryptophyta Species 0.000 title claims abstract description 54
- 238000001914 filtration Methods 0.000 claims abstract description 209
- 239000000725 suspension Substances 0.000 claims abstract description 140
- 238000005406 washing Methods 0.000 claims abstract description 26
- 239000007900 aqueous suspension Substances 0.000 claims abstract description 12
- 235000016425 Arthrospira platensis Nutrition 0.000 claims abstract description 7
- 240000002900 Arthrospira platensis Species 0.000 claims abstract description 7
- 229940082787 spirulina Drugs 0.000 claims abstract description 7
- 241000192497 Oscillatoria Species 0.000 claims abstract description 5
- 239000004744 fabric Substances 0.000 claims description 105
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 25
- 239000007788 liquid Substances 0.000 claims description 20
- 239000012530 fluid Substances 0.000 claims description 10
- 239000000706 filtrate Substances 0.000 claims description 9
- 238000005086 pumping Methods 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 5
- 238000000889 atomisation Methods 0.000 claims description 3
- 239000000839 emulsion Substances 0.000 claims description 3
- 238000000227 grinding Methods 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims description 2
- 238000004094 preconcentration Methods 0.000 abstract description 12
- 230000015572 biosynthetic process Effects 0.000 description 6
- 238000000926 separation method Methods 0.000 description 5
- 235000013305 food Nutrition 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 230000000050 nutritive effect Effects 0.000 description 3
- 102000004169 proteins and genes Human genes 0.000 description 2
- 108090000623 proteins and genes Proteins 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 241000894007 species Species 0.000 description 2
- 241001465754 Metazoa Species 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 239000004959 Rilsan Substances 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000001464 adherent effect Effects 0.000 description 1
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- 238000005119 centrifugation Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
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- 238000007796 conventional method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
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- 239000001301 oxygen Substances 0.000 description 1
- 238000009304 pastoral farming Methods 0.000 description 1
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- 239000004033 plastic Substances 0.000 description 1
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- 238000010298 pulverizing process Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
- C12N1/02—Separating microorganisms from their culture media
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G33/00—Cultivation of seaweed or algae
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23J—PROTEIN COMPOSITIONS FOR FOODSTUFFS; WORKING-UP PROTEINS FOR FOODSTUFFS; PHOSPHATIDE COMPOSITIONS FOR FOODSTUFFS
- A23J1/00—Obtaining protein compositions for foodstuffs; Bulk opening of eggs and separation of yolks from whites
- A23J1/009—Obtaining protein compositions for foodstuffs; Bulk opening of eggs and separation of yolks from whites from unicellular algae
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
- C12M33/00—Means for introduction, transport, positioning, extraction, harvesting, peeling or sampling of biological material in or from the apparatus
- C12M33/14—Means for introduction, transport, positioning, extraction, harvesting, peeling or sampling of biological material in or from the apparatus with filters, sieves or membranes
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
- C12M47/00—Means for after-treatment of the produced biomass or of the fermentation or metabolic products, e.g. storage of biomass
- C12M47/02—Separating microorganisms from the culture medium; Concentration of biomass
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/80—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in fisheries management
Definitions
- Microscopic algae for example of the Spirulina or Oscillatoria species, are isolated from aqueous suspensions thereof according to a multi-step process which comprises a pre-concentratioin step in which the suspension is fed along a filtration surface at a high contact velocity, followed with filtration, a washing and a pressing out step. Filtering devices of the drum type, the continuous belt type or the inclined plane type are also disclosed and claimed.
- the separation process of the invention applies particularly to the diluted suspensions of algae having a filamentous or helical shape.
- the algae of the Spirulina or ()scillatoria species such as. for example. the algae of the Spirulina or ()scillatoria species.
- suspensions usually have an algal concentration of (HM to 3 g (dry weight) per liter.
- these microscopic algae have various shapes and sizes. from a few microns to a few hundreds of microns.
- the Spirulina alga has the shape of an helix of about 200-400 microns length. consisting of turns of about 20 microns diameter.
- the filtration and/or pressingout techniques appear as being the most suitable ones. However. they cannot easily be operated on account of the size of the cells to be recovered. their mechanical strength. the high amount of liquid to be separated and the nature of the latter. which is strongly clogging since it has a high content of organic materials.
- the conventional filtration devices for example the vacuum drum filters and the belt filters are useless for the filtration of such suspensions. mainly since the filtration cake formed on the filtration cloth very quickly clogs the meshes ofthis cloth which forbids the satisfactory continuing of the operation.
- this operation mainly comprises two filtration steps: the first one consists in filtering the algae suspension under such specific conditions. as to avoid the clogging of the fabric and to obtain a concentrated suspension which has not the same defects as the initial diluted suspension with respect to the conventional filtration techniques.
- the second one is a conventional filtration steps.
- the separation process of this invention comprises a first pre concentration step. in which a suspension of microscopic algae is fed onto a filtration surface in such manner that the suspension. when contacting said filtration surface. has a sufficiently high relative contact velocity to carry away the forming filtration cake in the form of a concentrate suspension and a second step. in which the said concentrated suspension is filtered through a filtration surface. thus retaining an algae cake. It further comprises a third step. in which the said cake is washed by feeding water therethrough. a fourth step. in which water is pressed out from the washed cake. a fifth step. in which the resulting cake is converted to a fluid mud by mechanical breaking of a fraction of the algae contained therein. and a sixth step.
- Each of the filtration surfaces used in this process has mesh size of l-l00 microns. These surfaces may particularly consist of fabrics made of synthetic gut such as Rilsan (trade mark) gut. Nylon. polyester or stainless steel gauges may also be used.
- the suspension to be pre-concentrated has a velocity. when the kinematic energy thereof contacts the filtration surface. that a part ofthe liquid content thereof. usually -20% and preferably 0.5-57? by volume. does not filter through the filtration surface but flows therealong. thus carrying away the filtration cake which tends to form. so as to constitute a concentrated suspension which may thereafter be filtered under conventional conditions in the second step.
- the initial suspension is usually concentrated by 5 to 200 times. preferably to 200 times. in this pre-concentration step.
- the resulting concentrated suspension usually has an algal concentration from I to grams (dry weight) per liter. preferably from I to 10 grams per liter.
- the concentrated suspension recovered from the first step is filtered under conventional conditions.
- the third step consists in withdrawing the salts which contaminate the cake by water-washing. for example by means of one or more pulverization pipes and under sucking of the water through the filtration surface. This water-washing is sufficient to limit the ash-content to a value lower than the maximum tolerated by the standards for food products lie. 5% by weight).
- water is pressed out from the washed cake. for example to a water-content from to 83% by weight. for example by sucking thereof through the filtration surface.
- the resulting cake appears as a plastic solid material which cannot be pumped.
- This mechanical breaking which permits the fluidization of the said cake.
- This mechanical breaking which permits the fluidization of the said cake. may be carried out according to various techniques. for example by means of a mixer. a grinding pump or an emulsion homogeneizer: in the latter apparatus, the cake is subjected to a quick pressure release. from a pressure higher than 100 bars down to the atmospheric pressure.
- the fluidized cake is dried according to a conventional technique. for example by atomization or on rolls.
- the first step preconcentration operation according to the invention may be carried out with a number of filtration devices which are conceived in such manner that the algae suspension to be pre-concentrated. when contacting the filtration surface. is moved at a relative velocity sufficient for impeding the formation ofa cake sticking on the said filtration surface.
- FIG. shows a perferred association of filtration devices.
- a first device consists of an inclined plane filter (FIG. I). which mainly comprises a plane filtration cloth 1 inclined with respect to an horizontal plane and whose inclination angle (05) may range, for example, from 2 ln this device.
- the inclination of the filtration cloth (1) by a selected angle value (11)) usually from to 60. preferably from 10 to 30, permits the flowing of the suspension along the said filtration cloth, so as to impede the formation of an adherent filtration cake.
- the filtration cloth 1. usually of rectangular shape, may be placed on a plane carrier, itself rectangular. consisting of a grid. and maintained on the latter, for example by means of a fixed frame 6.
- the device also comprises a feed box 2 along the higher edge of the filtration cloth. a collector 3 along the lower edge of the said cloth for receiving the concentrated suspension resulting from the filtration and a recovery tank 4 below the filtration cloth 1 for collecting the filtrates.
- the device may also comprise a multiple position supporting device and a hinge along the lower edge of the carrier 5 of the cloth 1, so that the said carrier 5 may revolve to take any of the positions provided on the carrier 7.
- the suspension to be pre-concentrated is fed from a pipe 9 into the feed box 2 which may be provided with baffle-plates such as 10 for reducing the turbulence caused in the feed box 2 by the supply thereinto of the suspension from the pipe 9, so that a smooth flow of the suspension through the slot 11 of the said box 2 is obtained.
- baffle-plates such as 10 for reducing the turbulence caused in the feed box 2 by the supply thereinto of the suspension from the pipe 9, so that a smooth flow of the suspension through the slot 11 of the said box 2 is obtained.
- the suspension then flows along the filtration cloth 1 as a uniform sheet.
- the concentrated algae suspension which forms on the cloth 1 is carried along by the unfiltered liquid fraction down to the lower edge 1 of the said cloth, wherefrom it is collected in collector 3, from which it may be withdrawn by pumping through pipe 12 to be fed to the filtration zone ofthe following step.
- the filtrate is collected in the recovery tank 4, from which it may be flowed through pipe 13.
- the diluted suspension to be pre-concentrated may be fed at an hourly rate of l05O m" per sq.rn. of filtration area.
- the concentration of the resulting suspension may be. for example. l30 grams (dry weight) per liter. It is usually 5-15 g per liter.
- a second pre-concentration device consists of a vertical drum rotative filter, as shown on FIGS. 2 and 2A. which mainly comprises a vertical cylindrical drum able to revolve around its hollow shaft and whose external surface of the vertical wall, consisting for example of a grid or a perforated wall. supports the filtration cloth [7.
- This drum [4 is placed in a fixed tank 18 itself cylindrical and of same axis as the drum l4 and whose vertical wall is provided with at least one baffle-plate such as [9, consisting. for example. of a rectangular plate attached to the said vertical wall of the tank 18.
- This device also comprises a feeding pipe 20. placed above the annular zone 2] located between the vertical wall 16 of the drum l4 and the vertical wall of the tank 18, and a stationary set of pipes, placed inside the drum 14, for the withdrawing ofthe filtrates.
- Said set of pipes comprises a vertical pipe 22 leaving the drum [4 through its hollow shaft 15 and receiving the extremity of at least one afferent pipe as 23, the other extremity of which is located near the vertical wall 16 ofthe drum 14.
- the device also comprises a pipe 24 for withdrawing the concentrated mud from the tank 18.
- the device is fed with the algae suspension to be preconcentrated from pipe 20.
- the drum l4 revolves around its axis. for example at such a speed as to give to its vertical wall 16 a linear velocity of 0.5 5 meters per second.
- the filtration of a selected fraction of the liquid volume through the filtration cloth 17 is obtained by pumping through the pipes 22 and 23.
- the baffleplate 19 by disturbing the flowing of the suspension in the annular zone 21, impedes the said suspension to be circulated at the same speed as the drum 14.
- the difference in speed between the filtration cloth and the suspension to be preconcentrated (relative contact velocity along the said cloth) impedes the formation and/or the sticking of a filtration cake on the cloth 17.
- the diluted suspension to be pre-concentrated may be fed at an hourly rate of 3 10m sq.m. of filtration surface.
- the concentrated suspension obtained in this operation has, for example, an algal concentration of 3 8 g (dry weight) per liter.
- the device has the same features as above. except that the vertical axis of the drum 14 does not coincide with the vertical axis of the tank 18 and the vertical wall of the tank has no baffle-plate such as 19.
- the flowing of the suspension to be pre-concentrated around the drum is no more disturbed by such baffle-plates as 19 but by the fact that the horizontal cross-section of the annular zone 21 has not a constant width all around the drum l4, and the narrowing (resp. the widening) ofthis crosssection re sulting in an acceleration (resp. a slowing down) of the suspension flow.
- a third device which may be used in the preconcentration step of the process of the invention consists of a fixed drum-filter as shown on FIGS. 3 and 3A.
- a fixed drum-filter as shown on FIGS. 3 and 3A.
- the drum 25 is placed in a stationary tank 28 for example having the shape of a truncated cone and the same axis as the drum 25.
- the device also comprises at least one feed pipe such as 29. which opens along the higher side of the drum 25 wall. a pipe 30 for withdrawing the filtrates and a pipe 31 for withdrawing the concentrated suspension.
- the suspension to be pre-concentrated is injected onto the filtration cloth from pipe 29 at a contact speed sufficient for impeding the formation and/or the sticking of an algae cake.
- the injected suspension turns inside the drum as a vortex.
- the concentrated suspension accumulate at the bottom of the drum 25. wherefrom they are withdrawn through pipe 31.
- the filtrate passing into tank 28 is withdrawn through pipe 30.
- a fourth pre-concentration device consists of a belt filter as shown on FIGS. 4. 4A and 4C. It comprises a continuous mobile cloth belt 32 which is moved along a path at least of part of which is horizontal. This device also comprises at least one feed device 33 on FIG. 4 for pouring the suspension on the horizontal portion of the cloth 32 at a contact velocity. in the same direction as the cloth is moved. which is sufficient for impeding the formation or the sticking of a filtration cake on the said Cloth 32.
- the feed device 33 may consists. as shown for example on FIG. 4A. of a grazing injection pipe fed from a pipe under pressure 35.
- Said injection pipe 34 may consist of a pipe provided with a longitudinal slit 36.
- the plane comprising the slit 36 axis and the pipe 34 axis and the plane of the filtration cloth 32 meet at an angle a of [0 45 and preferably 20-40.
- the device for feeding the algae suspension to be pre-concentrated may also consist of a feed box under atmospheric pressure. such as shown by the respective reference 37 and 40 on FIG. 4B and 4C.
- the height of said feedbox must be sufficient for feeding the suspension flowed therefrom through slit 38 or over-flow shoot 41 at the required contact velocity.
- the axial plane of the slit 38 or of the over-flow-shoot 4I meets the plane of the filtration cloth 32 at an angle of I0 and preferably 20 40 (B on FIG. 4B and a on FIG. 4C
- the feed boxes 37 and 40 may be provided with either horizontal 39 on FIG. 4B or vertical 42 on FIG. 4C baffle-plates. so as to reduce the turbulence of the suspension contained therein.
- feed devices such as 33 may be provided along the horizontal path of the moving cloth FIG. 4.
- the cloth speed is usually from 0.5 to 20 centimeters per second.
- the suspension to be pre-concentrated is injected on the cloth 32 at an incidence angle of 10 45 and preferably 20 40 and. for example. at a velocity of l It) meters per second.
- a concentrated suspension is collected at the end of the horizontal portion of the filter.
- the device may treat an amount of suspension corresponding. for example. to 3 20 kg of dry material per sq. meter of cloth and per hour.
- the devices used for the first preconcentration step of the process are so conceived as to impede the formation ofa clogging cake. It is necessary for each of them that the filtration cloth be subjected to a washing step.
- the washing is intermittent and usually requires the stopping of the filtration step.
- the fixed or mobile drum filters Conversely. regarding the inclined plane filter or the belt filter, it may be carried out during the filtration step.
- the washing step consists of passing pressurized water through the filtration cloth. usually in the opposite direction with respect to the filtrates. or in the same direction. regarding the inclined plane filter.
- the second. third and fourth steps of the process may advantageously be carried out by using different zones of a single device. for example. a rotative filter or a belt filter.
- the device consists of a mobile continuous cloth belt which receives the concentrated suspension from the first step.
- the cloth first goes through a filtra tion zone where the suspension is usually subjected to a pressure decrease of less than I00 grams per sq. cm. preferably 4 25 grams per sq.cm.. so as to form a fil tration cake whose thickness is usually a few centimeters. for example 4 20 cm.
- the cake-bearing cloth is then transferred to a washing zone in which water is passed through the cake subjected to a pressure decrease which is not limited as before and may attain 750 g/sq.cm.
- the cloth bearing the washed cake then passes through a pressing-out zone. where said cake is subjected through the cloth to a pressure decrease which may also attain about 750 g/sq.cm.
- the resulting cake is then discharged from the cloth by means of a knife or a pneumatic system.
- the cloth made free of the cake is then transferred into a washing zone. where pressurized water is passed therethrough. usually in opposite direction with respect to the filtrates.
- the washed cloth is finally returned to the initial filtration zone to receive a new charge of the algae suspension to be treated.
- the said device rotative filter or belt filter
- washing and pressing-out steps may be carried out continuously.
- any device of the first (preconcentration) step as hereinbefore described may be associated with any device of the second. third and fourth steps (filtration. washing. pressing-out) also hereinbefore described.
- a preferred association comprises the use of the same belt filter for the pre-concentration step and the three following steps.
- Such a device is shown on FIG. 5.
- the same filtration cloth belt 32 comes along a pre-concentration zone 43, where it is fed from 33 as described with respect to the pre-concentration step.
- the cake is discharged at 50 and the cloth goes into the washing zone SL
- the sucking tanks such as 47 and 48 produce the pressure decrease required in the filtration. washing and pressing-out zones.
- Injection nozzles such as 49 and 52 are respectively used for washing the cake in the washing zone 45 and washing the cloth in the washing zone 51.
- a process for separating microscopic algae from a dilute aqueous suspension thereof. comprising a first step, in which the aqueous suspension of microscopic algae having an algae content of about 0.01 to 3 grams of dry weight per liter is fed onto a filtration surface. with such a relative velocity that said suspension. when contacting the filtration surface. carries away any forming filtration cake. and that a portion of about 0.5 to 2071 of the liquid volume of the said suspension does not filter through said filtration surface resulting in a concentrated suspension.
- a second step. in which the said concentrated suspension is filtered through a filtra tion surface which retains an algae cake.
- a process according to claim l wherein the concentrated suspension issuing from the first step is filtercd under a pressure decrease lower than lilil grams per sq. cm.. in the second step.
- a process according to claim 1. further comprising a step of washing the filtration surface after the first step by means of pressurized water.
- a process according to claim wherein the suspension is fed at an hourly rate of [0-50 in" per square meter of filtration area of said filtration cloth. inclined with respect to an horizontal plane by such an angle that 0.5 to 20% of the liquid volume of said suspension flows along said filtration cloth.
- a rotative drum filter comprising a rotative. vertical. cylindrical drum. the vertical perforated wall of which supports a filtration cloth on its ex ternal surface. said drum being placed in a stationary cylindrical tank of same axis as said drum. the vertical wall of said tank being provided with at least one baffleplate on its internal surface. and wherein the suspen sion. fed to the annular zone located between the external vertical wall of said drum and the internal vertical wall of said tank. is circulated in said annular zone by the rotation of said drum. the circulation of said suspension being disturbed by said baffle-plate in such a manner that. during filtration. by pumping through said filtration cloth. ofa fraction of the liquid volume of said suspension. the relative velocity of said suspension in contact with said filtration cloth is sufficient to carry away from the surface of said filtration cloth any forming filtration cake. in the form of a concentrated suspension, which is received at the bottom of said annular zone.
- a process according to claim 1. wherein. in the first step. there is used a rotative drum filter comprising a rotative. vertical. cyclindrical drum. the vertical per forated wall of which supports a filtration cloth on its external surface. said drum being placed in a stationary cylindrical tank the axis of which is distinct from the axis of said drum. and wherein the suspension. fed to the annular zone located between the external vertical wall of said drum. and the internal vertical wall of said tank is circulated in said annular zone by the rotation of said drum. the circulation of said suspension being disturbed by the variation of the cross-section of said annular zone all around said drum. in such a manner that during filtration. by pumping through said filtration cloth. ofa fraction ofthe liquid volume of said suspension. the relative velocity of said suspension in contact with said filtration cloth is sufficient to carry away from the surface of said filtration cloth any forming filtration cake in the form of a concentration suspension. which is received at the bottom of said annular zone.
- a process according to claim 1. wherein in the first step. there is used a stationary drum filter comprising a stationary drum of vertical axis in the shape of a truncated cone enlarging towards the top, the inclined perforated wall of which supports a filtration cloth on its internal surface, said drum being placed in a stationary tank, and wherein the suspension is fed along the higher edge of the internal surface of said drum, in such a manner that the suspension circulates inside said drum at a speed sufficient to carry away from the surface of said filtration cloth any forming filtration cake, in the form of a concentrated suspension which is received at the bottom of said drum.
- a process for separating microscopic algae from a dilute aqueous solution having an algae content of about 0.0] to 3 grams of dry weight per liter comprising the steps of feeding said aqueous suspension onto a filtration surface with such a velocity relative to the filtration surface that said suspension, when contacting the filtration surface, carries away any forming filtration cakes. and that a portion of about 0.5 to of the liquid volume of said suspension does not filter through said filtration surface, resulting in a concentrated suspension. and filtering said concentrated suspension to form a filtration cake of algae on a filtration surface.
- a process for separating microscopic algae from a dilute aqueous suspension thereof comprising a first step in which the aqueous suspension, having an algae content of about 0.01 to 3 grams ofdry weight per liter, is fed onto a filtration surface with such a relative velocity that said suspension, when contacting the filtration surface carries away any forming filtration cake and that a portion of about 0.5 to 20% of the liquid volume of said suspension does not filter through said filtration surface, resulting in a concentrated suspension.
- a second step in which said concentrated suspension is filtered through a filtration surface which retains an algae cake
- a third step in which the said cake is washed by feeding water therethrough
- a fourth step in which water is pressed out from the washed cake
- a fifth step in which the resulting cake is converted to a fluid mud by mechanical breaking of a fraction of the algae contained therein
- a sixth step in which the said fluid mud is transferred to a drying zone where it is dried, the filtration surfaces having each a mesh size in the range of 10-100 microns
- the concentration of the first step, the filtration of the second step, the washing of the third step and the pressing-out of the fourth step are carried out on the same filtration surface of a belt filter, which is successively passed through four different zones, and the pressed-out cake is discharged at the end ofthe fourth step
- said belt filter comprises a mobile, continuous perforated belt supporting a filtration cloth and moved along a path, at least a portion of which is included
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Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR7128186A FR2148732A5 (enrdf_load_stackoverflow) | 1971-07-30 | 1971-07-30 |
Publications (1)
Publication Number | Publication Date |
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US3875052A true US3875052A (en) | 1975-04-01 |
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Application Number | Title | Priority Date | Filing Date |
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US274252A Expired - Lifetime US3875052A (en) | 1971-07-30 | 1972-07-24 | Process for separating microscopic algae |
Country Status (8)
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US (1) | US3875052A (enrdf_load_stackoverflow) |
JP (1) | JPS565513B1 (enrdf_load_stackoverflow) |
BR (1) | BR7205084D0 (enrdf_load_stackoverflow) |
CA (1) | CA984308A (enrdf_load_stackoverflow) |
FR (1) | FR2148732A5 (enrdf_load_stackoverflow) |
IL (1) | IL40007A (enrdf_load_stackoverflow) |
IT (1) | IT963484B (enrdf_load_stackoverflow) |
OA (1) | OA04669A (enrdf_load_stackoverflow) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4192743A (en) * | 1974-05-08 | 1980-03-11 | Albert Klein Kg | Process of dewatering sludge-type material and installation for carrying out the process |
ES2174679A1 (es) * | 1999-09-03 | 2002-11-01 | Consejo Superior De Investiaga | Dispositivo con hilo de nylon para recuperar filamentos microscopicos. |
US20040121447A1 (en) * | 2002-11-07 | 2004-06-24 | Real Fournier | Method and apparatus for concentrating an aqueous suspension of microalgae |
US20090134091A1 (en) * | 2007-11-24 | 2009-05-28 | Green Vision Energy Corporation | Method for removing undesirable components from water while containing, cultivating, and harvesting photosynthetic marine microorganisms within water |
US20100167339A1 (en) * | 2007-06-19 | 2010-07-01 | Eastman Chemical Company | Process for microalgae conditioning and concentration |
US20100224574A1 (en) * | 2009-03-09 | 2010-09-09 | Youngs Ross O | Method and apparatus for separating particles from a liquid |
US20110253612A1 (en) * | 2010-04-06 | 2011-10-20 | Arizona Board Of Regents For And On Behalf Of Arizona State University | Extraction With Fractionation of Oil and Co-Products From Oleaginous Material |
US20120288917A1 (en) * | 2008-08-01 | 2012-11-15 | Algae-Tech (Uk) Ltd | Algae growth system |
CN104159442A (zh) * | 2011-12-30 | 2014-11-19 | Spxapv丹麦公司 | 旋转过滤器 |
CN109207359A (zh) * | 2018-08-29 | 2019-01-15 | 福清市新大泽螺旋藻有限公司 | 一种螺旋藻采收机及其使用方法 |
WO2024134649A1 (en) * | 2022-12-21 | 2024-06-27 | Algaecore Technologies Ltd | System and method for scalable production of cyanobacteria biomass |
Families Citing this family (5)
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FR2194465A1 (en) * | 1972-08-03 | 1974-03-01 | Triton Sa | Filter for industrial cleaning fluids - with endless belt filter from which deposits are continuously removed by spray |
PL138171B1 (en) * | 1983-10-12 | 1986-08-30 | Politechnika Warszawska | Apparatus for dynamic classification of suspensions of solids in liquid |
FR2572303A1 (fr) * | 1984-10-25 | 1986-05-02 | Goavec Sa | Dispositif de filtration a bande filtrante destine a la filtration fine de liquides fragiles |
WO1991016961A1 (en) * | 1990-05-03 | 1991-11-14 | Nytek A/S | Filter |
JP7709061B2 (ja) | 2020-09-30 | 2025-07-16 | 日亜化学工業株式会社 | 複合部材、その製造方法、およびモータの回転子 |
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- 1972-07-28 IT IT7227571A patent/IT963484B/it active
- 1972-07-28 CA CA148,238A patent/CA984308A/en not_active Expired
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US2969225A (en) * | 1955-02-09 | 1961-01-24 | Harry N Jenks | Detention and mixing apparatus for treating waste liquids |
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Cited By (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4192743A (en) * | 1974-05-08 | 1980-03-11 | Albert Klein Kg | Process of dewatering sludge-type material and installation for carrying out the process |
ES2174679A1 (es) * | 1999-09-03 | 2002-11-01 | Consejo Superior De Investiaga | Dispositivo con hilo de nylon para recuperar filamentos microscopicos. |
ES2174679B1 (es) * | 1999-09-03 | 2004-08-16 | Consejo Superior De Investiagaciones Cientificas | Dispositivo con hilo de nylon para recuperar filamentos microscopicos. |
US20040121447A1 (en) * | 2002-11-07 | 2004-06-24 | Real Fournier | Method and apparatus for concentrating an aqueous suspension of microalgae |
US20080213868A1 (en) * | 2002-11-07 | 2008-09-04 | Rival | Concentrated aqueous suspensions of microalgae |
US9358553B2 (en) | 2007-06-19 | 2016-06-07 | Renewable Algal Energy, Llc | Process for microalgae conditioning and concentration |
US8512998B2 (en) | 2007-06-19 | 2013-08-20 | Renewable Algal Energy, Llc | Process for microalgae conditioning and concentration |
US20100176062A1 (en) * | 2007-06-19 | 2010-07-15 | Eastman Chemical Company | Process and apparatus for adsorptive bubble separation using a dense foam |
US20100181234A1 (en) * | 2007-06-19 | 2010-07-22 | Eastman Chemical Company | Process and apparatus for adsorptive bubble separation |
EP2985082A1 (en) | 2007-06-19 | 2016-02-17 | Renewable Algal Energy, LLC | Process for microalgae conditioning and concentration |
EP3219390A1 (en) | 2007-06-19 | 2017-09-20 | Renewable Algal Energy, LLC | Process for microalgae conditioning and concentration |
US8251228B2 (en) | 2007-06-19 | 2012-08-28 | Renewable Algal Energy, Llc | Process and apparatus for adsorptive bubble separation |
US20100167339A1 (en) * | 2007-06-19 | 2010-07-01 | Eastman Chemical Company | Process for microalgae conditioning and concentration |
US8196750B2 (en) | 2007-06-19 | 2012-06-12 | Renewable Algal Energy, Llc | Process and apparatus for adsorptive bubble separation using a dense foam |
US20090134091A1 (en) * | 2007-11-24 | 2009-05-28 | Green Vision Energy Corporation | Method for removing undesirable components from water while containing, cultivating, and harvesting photosynthetic marine microorganisms within water |
US9688951B2 (en) * | 2008-08-01 | 2017-06-27 | Algae-Tech Ltd. | Algae growth system |
US20120288917A1 (en) * | 2008-08-01 | 2012-11-15 | Algae-Tech (Uk) Ltd | Algae growth system |
US8092691B2 (en) * | 2009-03-09 | 2012-01-10 | Univenture, Inc. | Method and apparatus for separating particles from a liquid |
US8286801B2 (en) | 2009-03-09 | 2012-10-16 | Univenture, Inc. | Method and apparatus for separating particles from a liquid |
US20100224574A1 (en) * | 2009-03-09 | 2010-09-09 | Youngs Ross O | Method and apparatus for separating particles from a liquid |
US8212060B2 (en) | 2010-04-06 | 2012-07-03 | Arizona Board Of Regents For And On Behalf Of Arizona State University | Extraction with fractionation of oil and co-products from oleaginous material |
US8524929B2 (en) | 2010-04-06 | 2013-09-03 | Arizona Board Of Regents For And On Behalf Of Arizona State University | Extraction with fractionation of lipids and proteins from oleaginous material |
US8318963B2 (en) | 2010-04-06 | 2012-11-27 | Arizona Board Of Regents For And On Behalf Of Arizona State University | Extraction with fractionation of lipids and co-products from oleaginous material |
US8222437B2 (en) | 2010-04-06 | 2012-07-17 | Arizona Board Of Regents For And On Behalf Of Arizona State University | Extraction of lipids from oleaginous material |
US8157994B2 (en) * | 2010-04-06 | 2012-04-17 | Arizona Board Of Regents For And On Behalf Of Arizona State University | Extraction with fractionation of oil and co-products from oleaginous material |
US20110253612A1 (en) * | 2010-04-06 | 2011-10-20 | Arizona Board Of Regents For And On Behalf Of Arizona State University | Extraction With Fractionation of Oil and Co-Products From Oleaginous Material |
CN104159442A (zh) * | 2011-12-30 | 2014-11-19 | Spxapv丹麦公司 | 旋转过滤器 |
CN104159442B (zh) * | 2011-12-30 | 2016-09-21 | Spxapv丹麦公司 | 旋转过滤器 |
CN109207359A (zh) * | 2018-08-29 | 2019-01-15 | 福清市新大泽螺旋藻有限公司 | 一种螺旋藻采收机及其使用方法 |
CN109207359B (zh) * | 2018-08-29 | 2021-06-08 | 福清市新大泽螺旋藻有限公司 | 一种螺旋藻采收机及其使用方法 |
WO2024134649A1 (en) * | 2022-12-21 | 2024-06-27 | Algaecore Technologies Ltd | System and method for scalable production of cyanobacteria biomass |
Also Published As
Publication number | Publication date |
---|---|
CA984308A (en) | 1976-02-24 |
BR7205084D0 (pt) | 1973-06-07 |
JPS565513B1 (enrdf_load_stackoverflow) | 1981-02-05 |
IT963484B (it) | 1974-01-10 |
OA04669A (fr) | 1980-07-31 |
IL40007A (en) | 1975-07-28 |
FR2148732A5 (enrdf_load_stackoverflow) | 1973-03-23 |
IL40007A0 (en) | 1972-09-28 |
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