Patent Abstract:
An improvement is described for the processing of biological material in a continuous stream by the application of radiant energy taken from the wavelengths from infrared to ultraviolet, and its absorption by a feedstock in a workspace of featuring controlled turbulence created by one or more counter-rotating disk impellers. The absorbed energy and the controlled turbulence patterns create a continuous process of productive change in a feed into the reactor, with separated light and heavy product output streams flowing both inward and outward from the axis in radial counterflow. The basic mechanism of processing can be applied to a wide range of feedstocks, from the promotion of the growth of algae to make biofuel or other forms of aquaculture, to a use in the controlled combustion of organic material to make biochar.

Full Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/437,277 filed Jan. 28, 2011. 
     
    
     FIELD 
       [0002]    The present disclosure is related to drying and gas or vapor contact with solids, by continuous processing with centrifugal force and heating; cleaning and liquid contact with solids with means for collecting escaping material; classifying, separating and assorting solids, with heat treatment; classifying, separating and assorting solids with fluid suspension with grading deposition of gaseous feed with fluidically induced, unidirectional swirling; or classifying, separating and assorting solids, with a liquid feed grading deposition including rotational hydrodynamic extraction; and pumps where one fluid is pumped by contact or entrainment with another within a rotary impeller, or by a jet. 
       BACKGROUND 
       [0003]    The separation of the products of a reaction taking place within a feedstock is currently done in several ways. Examples include batch processing, gravity separation, and centrifugal separation. A new approach is a radial counterflow reactor, which uses a feedstock in a workspace with controlled turbulence patterns created by the rotation of one or more disk impellers, and is described in several disclosures by the present applicants. 
         [0004]    There are currently a variety of vessels for the growth or other processing of biological material. The current approaches do not allow for the efficient application of energy throughout the material within the vessel, while simultaneously stripping out exceptionally beneficial or harmful components within the vessel in a continuous process which lends itself to high volume. 
         [0005]    Two examples will be used here to illustrate this. The first is the promotion of algae growth for the production of biofuels from CO 2 . Typically the algae is placed with sterilized water and nutrients in clear vessels such as tubes to allow sunlight to shine in, and CO 2  is bubbled up in the tubes to mix with the algae. There is inefficiency in the application of the sunlight energy to the tube, where much of the algae in the interior of the column are shielded from the sun while that on the exterior may get too much. A need exists for improved access of light for photosynthesis to algae in a bioreactor or in a pond. 
         [0006]    The distribution of the CO 2  in the tube also tends to be uneven because there is not enough mixing. When the algae has had time to create oils and other hydrocarbons, which here will be generally called lipids, then the algae has to be extracted, dried, and processed to remove the lipids. This is a wasteful and energy intensive extra step, and because this is a batch process, there is not a continuous stream that would lend itself to high volume. 
         [0007]    It would be preferable to have a continuous lipid production process that did not depend on killing the algae. A goal of research has been to engineer a “lipid trigger” in the algae to make it extrude lipids, instead of storing them internally, and to do so continuously, instead of only producing them intermittently during periods when there is no cell division. But if a live algae colony were able to be continuously producing lipids in this way, there is no efficient way to extract the lipids to keep them from contaminating the algae environment. There is also no way to, at the same time, continuously separate the dead algae from the live ones, to keep the most productive members flourishing. Also, there is a need to strip out the oxygen produced by the algae to favor the forward photosynthesis reaction for enhancing algae growth. 
         [0008]    Where algae is in a pond, oxygen is produced by photosynthesis and released to the atmosphere, but dissolved oxygen in the water is consumed by the decay of dead algae, and the depletion of oxygen in the water leads to dead zones where fish cannot live. 
         [0009]    In shrimp and fish aquaculture, oxygen is desired, instead of carbon dioxide, but the same need exists for continuous stripping of waste gases and circulation of water to extract feces and other waste material. 
         [0010]    To use another example, the combustion of material to create biochar is typically done in furnaces in a batch process. There is a need for continuous mixing that ensures that heat energy will be evenly applied throughout the feedstock, and for an efficient mechanism for continuously stripping out volatile gases or liquids to aid the forward reaction. 
         [0011]    The applicants have described a variety of variations on the design of a radial counterflow reactor comprising one or more rotating disk impellers, which has many benefits in establishing a radial counterflow pattern with lighter elements continuously migrating toward the axis, and heavier elements toward the periphery. This radial counterflow reactor idea has been described through its application to the continuous processing of gases, liquids and sludge. 
       SUMMARY 
       [0012]    A radial counterflow reactor is described featuring radiant energy, from among the wavelengths from infrared to ultraviolet, applied to the workspace. The reactor typically comprises two approximately parallel counter-rotating disk impellers, defining a turbulent workspace between them. The workspace can also be defined by a single impeller approximately parallel to a static casing. The disk impellers are conductive to the radiant energy, allowing at least some portion of the radiant energy to pass through them into the workspace to transform the feed. The radiant energy can come from emitting elements which are outside of the impellers and the workspace, or the radiant energy can come from elements embedded in the impellers. 
         [0013]    One example design is a photobioreactor with two counter-rotating disk impellers, defining a turbulent workspace between them. The disk impellers are transparent to radiant energy, to allow an applied radiant energy, from infrared to ultraviolet, to be transmitted through them into the workspace to transform the feed. This type of photobioreactor reactor is especially useful for the growth and processing of biological and organic material, including in aquaculture. 
         [0014]    For example, algae can be grown between transparent disk impellers in an axenic closed photobioreactor system, with improved means for extraction of products such as lipids for oil production. The impellers can be oppositely rotating solid disks, or moving liquid disk layers created by an array of jets. The algae feedstock, together with water, CO 2  and nutrients, is fed into the workspace and slowly sheared by the impellers, creating a fractal network of branching vortices where controlled turbulence and centrifugal force spins heavier components toward the periphery of the vortices and toward the periphery of the disks. At the same time, suction applied to the axial port in the upper disk impeller by a suction pump draws the lighter products such as lipids inward in a sink flow through the cores of the vortices, to be exhausted out of the axial port. The transparent disk impellers can be solid or liquid. If moving liquid disk layers form the impellers, they can contain dissolved nutrients or gases to be supplied by diffusion to the workspace, and they can also carry away wastes through drains in the impeller layers. In addition, the liquid impeller layers can supply hot or cool water as needed. Dead algae sink and are swept to the periphery of the photobioreactor where they are extracted as a sludge. Continuous gentle churning of the algae in this way exposes more of them to the light and extracts the waste products. 
         [0015]    In an embodiment for shrimp farming, algae and shrimp may coexist in the photobioreactor such that the shrimp eat the algae. Dead shrimp and feces are spun out by the disk impellers while live shrimp thrive among the live algae being nourished at the center. Methane and other waste gases are stripped out continuously and oxygen is introduced along with the recycled water. 
         [0016]    In an embodiment for fish farming, feces and dead fish are spun to the periphery of the photobioreactor where they can be easily collected at a wall, while the water is extracted, clarified, degassed, and aerated prior to being reintroduced to the tank. 
         [0017]    In another example design, biological and organic material is processed by radiant energy coming out of the solid impellers in a biochar reactor where wood or other organic waste is pyrolyzed by heat applied through heated impellers, with biochar accumulating at the periphery, and bio-oil and gases exhausted out of the axis. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  shows a cross section of a radial counterflow reactor utilizing absorbed energy applied into a feedstock, showing the basic components, as well as the flow of a feedstock and energy into it, and the flow of byproducts out. 
           [0019]      FIG. 2  shows a closeup of a portion of the reactor shown in  FIG. 1 , with more detail for the workspace. 
           [0020]      FIG. 3  shows a schematic side view of the flow patterns in the workspace. 
           [0021]      FIG. 4  shows a head-on view of the flow patterns in the workspace, featuring nested vortices. 
           [0022]      FIG. 5  shows a top view of the bottom disk impeller, showing the ports, vanes and other components. 
           [0023]      FIG. 6  shows a side cross section view of the bottom disk impeller shown in  FIG. 5 . 
           [0024]      FIG. 7  shows the superimposed patterns of the vanes for the top and bottom impellers, at a starting point in their counter-rotation. 
           [0025]      FIG. 8  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 10° in opposite directions. 
           [0026]      FIG. 9  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 20° in opposite directions. 
           [0027]      FIG. 10  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 30° in opposite directions. 
           [0028]      FIG. 11  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 40° in opposite directions. 
           [0029]      FIG. 12  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 50° in opposite directions. 
           [0030]      FIG. 13  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 60° in opposite directions. 
           [0031]      FIG. 14  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 70° in opposite directions. 
           [0032]      FIG. 15  shows the superimposed patterns of the vanes for the top and bottom impellers, rotated by 80° in opposite directions. 
           [0033]      FIG. 16  shows a set of flows for a radial counterflow algae photobioreactor. 
           [0034]      FIG. 17  shows a set of flows for a radial counterflow biochar bioreactor. 
           [0035]      FIG. 18  shows a top view of an array of jets to create a moving liquid disk impeller. 
           [0036]      FIG. 19  shows a cross section of two liquid impellers in a photobioreactor for aquaculture. 
       
    
    
     DRAWING REFERENCE NUMERALS 
       [0000]    
       
           1 —feed source 
           2 —feed transfer 
           3 —axial feed conduit 
           4 —axial feed port 
           5 —baffle 
           6 —bottom disk impeller 
           7 —top disk impeller 
           8 —rotation of top disk impeller 
           9 —rotation of bottom disk impeller 
           10 —axis of rotation 
           11 —workspace 
           12 —periphery of the workspace 
           13 —heavy products exhaust port 
           14 —heavy products collection 
           15 —heavy products transfer 
           16 —heavy products storage 
           17 —sink flow 
           18 —axial exhaust port 
           19 —axial suction pump 
           20 —lighter products transfer 
           21 —lighter products receptacle 
           22 —axial support shaft 
           23 —upper exhaust conduit 
           24 —upper disk bearing and seal 
           25 —lower intake conduit 
           26 —lower disk bearing and seal 
           27 —base support 
           28 —prime mover 
           30 —lower drive track 
           31 —upper drive track 
           32 —support wheel 
           33 —sleeper wheel 
           34 —sleeper wheel support 
           35 —drive shield wall 
           36 —output deflector wall 
           37 —output vent 
           38 —heavy product screw conveyor 
           39 —pinch section 
           40 —pinch opening 
           41 —radiant energy source 
           42 —absorption into feed 
           45 —axial feed pump 
           46 —feed flow 
           47 —sink flow 
           48 —heavy products flow 
           50 —vortex in shear layer 
           51 —vane on lower disk 
           52 —vane on baffle 
           53 —vane on upper disk impeller 
           54 —crossflow filter inset into bottom disk impeller 
           55 —liquid flow through crossflow filter 
           56 —rugose ridges on bottom disk impeller 
           56   a —gas vent on top disk impeller 
           57 —rugose ridges on top disk impeller 
           60 —boundary layer 
           61 —direction of flow of boundary layer 
           62 —flow from boundary layer to shear layer 
           63 —shear layer 
           64 —outer part of vortex 
           65 —direction of flow of outer vortex 
           66 —movement from shear layer to boundary layer 
           67 —inner part of vortex 
           68 —direction of flow of inner vortex 
           69 —inward sink flow 
           70 —vortex with counterclockwise rotation 
           71 —vortex with counterclockwise rotation 
           72 —centrifugal separation 
           73 —bottom impeller 
           74 —first vane 
           75 —second vane 
           76 —third vane 
           77 —fourth vane 
           78 —edge of baffle 
           79 —conical apex of screw feed conveyor 
           80 —vane crossing intersection 
           81 —corresponding inverted vane on top disk impeller 
           82 —first intersection axis 
           83 —second intersection axis 
           84 —third intersection axis 
           85 —fourth intersection axis 
           86 —fifth intersection axis 
           87 —sixth intersection axis 
           88 —seventh intersection axis 
           89 —eighth intersection axis 
           90 —rugose ridge on bottom disk impeller 
           91 —example of corresponding inverted rugose ridge on top disk impeller 
           92 —gas vent 
           93 —drive shield wall brace 
           96 —straight vane on bottom impeller 
           97 —straight vane on top impeller 
           98 —heavy products flow 
           99 —light products sink flow 
           100 —vortex network 
           101 —main supply pipe 
           102 —branch supply pipe 
           103 —liquid jet nozzle 
           104 —area of jet 
           105 —direction of flow 
           106 —drain inlet 
           107 —drain pipe 
           108 —central drain 
           109 —central supply pipe 
           110 —axial exhaust 
           111 —support frame 
           112 —support float 
           113 —peripheral wall 
           114 —upper liquid impeller 
           115 —lower liquid impeller 
           116 —turbulence flow 
           117 —nutrients 
           118 —waste products in liquid impeller 
           119 —supply inlet 
           120 —drain outlet 
       
     
       DETAILED DESCRIPTION 
       [0150]    Three examples will be given of a radial counterflow reactor with radiant energy applied to the feed. Each comprises a closed vessel with one or more feed stock input ports, one or more output ports for lighter products, and one or more output ports for heavier products, plus a source of radiant energy, in wavelengths selected from infrared to ultraviolet, to be to be absorbed by the feedstock. The first example will describe a photobioreactor with solid impellers. The second example describes a more simplified photobioreactor with liquid impellers. Both of these examples use radiant energy transmitted through transparent impellers. The third example is a biochar processor which also uses solid impellers, which are heated, either by the application of external heat or internal heating elements. 
       Algae Processor 
       [0151]    This reactor will first be described in an exemplary configuration as a photobioreactor for growing lipid-producing algae. It will be appreciated by the skilled practitioner that this example is not meant to restrict the possible applications of this description to the solution of other types of problems. Similarly, the design disclosed here is exemplary, and is not meant to preclude any modified design to suit a particular purpose. 
         [0152]    A feed source  1  comprises storage for a transportable feed, such as algae, combined with water, CO 2 , and nutrients. A feed transfer  2  brings the feed into the photobioreactor, by means such as pumps, conveyors or a gravity feed, into an axial feed conduit  3 , leading to an axial feed port  4 , where the feed enters the photobioreactor in a space underneath a baffle  5 , which is located between a bottom disk impeller  6  and top disk impeller  7 . These two disk impellers, which act as centrifugal pumps, rotate in opposite directions, such as those shown at  8  and  9 , about an axis of rotation  10 . A workspace  11  is defined in the space between the disk impellers. The workspace has boundary layers along the surfaces of the impellers, and a shear zone between the boundary layers, where amplified centrifugal force in organized vortex turbulence creates separation between the heavy and lighter products. 
         [0153]    After the algae is introduced into the photobioreactor, it is expected to multiply and grow there within it, and the primary feed from then on will be water along with CO 2  and nutrients to promote proper growth. 
         [0154]    The heavier products, such as an algae sludge, move toward the periphery of the workspace  12  where they are extruded, falling through a heavy products exhaust port  13  to be collected, in this case into an annular heavy products collection trough  14 , where the heavy products transfer means  15  convey the heavy products to the heavy products storage  16 . Meanwhile, while the heavy products migrate outward, an inward sink flow  17  is set up above the baffle, leading inward to an axial exhaust port  18 . The sink flow is forced by an axial suction pump  19 , in this case a screw conveyor. This pump can also be a mechanical pump or any other kind of appropriate pump to draw out the light products axially so a lighter products transfer  20  can convey them to a lighter products receptacle  21 . These lighter products include anything with a lower specific gravity than the heavier products. For example, the lighter products can include lipids extruded by the algae and oils as well as gases including oxygen produced by photosynthesis. 
         [0155]    The disks and the conveyor pumps in this design are supported by an axial support shaft  22 , which extends downward through the upper exhaust conduit casing  23 . This casing has the support for the upper disk bearing and seal  24 , which preferably contains a combination thrust bearing and rotary seal. A similar disk bearing and seal is in the casing for the lower disk. If the disk bearing and seal  24  is made to be movable up and down, such as by a telescoping upper exhaust conduit casing  23  and/or a similar one for the bottom disk impeller, then the separation between the top and bottom disk impellers  7  and  6  can be changed if needed. For instance, in the example of algae, a relatively wide separation could be used for an algae growth process, and a narrower one could be used to concentrate and dewater a resulting algae sludge. The axial support shaft  22  preferably also extends down through the axial feed conduit  3 , which has an axial feed pump  25 , in this case a screw conveyor, and lower disk bearing and seal  26 . Because these screw conveyors are tied to the disk impeller motion and the disk impellers have opposite rotation  8  and  9 , the screw conveyors in this design have an opposite slope in order to make a consistent movement of material upward in both cases. A base support  27  anchors the assembly. 
         [0156]    On the periphery of the disks is a prime mover  28  to turn the disk impellers in counter-rotation. This prime mover  28  can be a motor or another source of motive power such as wind or water power. The motor can be coupled to the hub or another part of the disk impellers in order to turn them. In this instance, the prime mover is coupled to a peripheral drive wheel  29  which simultaneously contacts the bottom disk impeller  6  at a bottom drive track  30 , and the top disk impeller  7  at a top drive track  31 . The rotation of the drive wheel  29  would therefore turn the two disk impellers in opposite directions. The drive wheel would preferably be a straight or spiral bevel gear, and the drive tracks would be compatible gear tracks. Support wheels such as at  32  contacting the opposite side of the disk impeller from the drive tracks will help to maintain a consistent engagement of the drive wheel  29  with the drive track such as at  30 . Sleeper wheels such as at  33  also maintain a consistent separation of the disks, and are supported by sleeper wheel supports such as at  34 . 
         [0157]    Inboard of the drive wheels are barrier walls to shield the drive components from the products inside, and to direct their flow. The drive shield wall  35  is an annular wall attached to the top disk impeller, and is a backup barrier to prevent the products from the interior of the photobioreactor from clogging the drive system. Inboard of the drive shield wall  35  is the output deflector wall  36 , which is also an annular wall, but this time attached to the bottom disk impeller, and angled inward so that the outward flow from the periphery is deflected downward to the heavy products exhaust port  13  and the heavy products collection trough  14 . On the top of this output space, an output vent  37  allows remaining gases from the heavy product to escape. The collection trough  14  for the heavy product can contain a conveyor to further collect it, such as an annular heavy product screw conveyor  38  in the bottom of the trough, ending in a tangential branch for dumping the product into a hopper. 
         [0158]    Inboard of these barrier walls, the separation of the disks narrows to the pinch section  39 , where heavy output products are squeezed and concentrated, beginning with the pinch opening  40 , where the workspace narrows. 
         [0159]    The passage of feed into the workspace, while the disk impellers are in motion, creates a fractal network of vortices in the shear layer, with lighter products converging in a sink flow  17  into the axial exhaust port  18 . At the same time, radiant energy, selected from the range of wavelengths from infrared to ultraviolet, is transmitted by a radiant energy source  41 , so that it is absorbed into the feed  42  in the workspace. 
         [0160]    This radiant energy transmission is done by making the disk impellers transparent or conductive to the radiant energy. For this example of an algae photobioreactor, the transparent disks allow the energy from sunlight or other artificial light energy to pass through them into the feed to be absorbed, including the wavelengths most beneficial for algae growth. 
         [0161]    If the algae can benefit from the maximum amount of exposure to light, it is preferable for both disk impellers  6  and  7  to be transparent, and for there to be a light source both above and below the disks. This can be done with a reflector for a single light source such as the sun, or with duplicate artificial light sources above and below the disks. If the photobioreactor described here is duplicated in a stack, then the light source for the bottom of one photobioreactor can serve as the light source for the top of another. As an alternative, a single light source can be reflected back into the feed from a mirror finish on the disk impeller opposite the transparent disk impeller. 
         [0162]    As the disk impellers slowly turn, the algae in the workspace are slowly swirled and rotated in the vortex flows, being exposed to light from every side, and continuously absorbing energy, like a roast being rotated on a spit. Heat flux due to forced convection sweeping the heat transfer surfaces is 50 W/cm2 which is better than static heating (pool boiling) at only 20, Controlled agitation of the algae maximizes the energy flux into them. This controlled agitation also provides radially inward pathways for the extraction of oxygen from photosynthesis, ammonia, H2S, oil, and clean water through the axial exhaust port  18 , here shown as an opening at the center of the top disk. The axial extraction of light fractions enables a continuous process which favors photosynthesis by extracting the products. 
         [0163]    The disk impellers may be solid transparent disks, screens, radial arms, or other configurations and materials permitting flux of radiant energy into the workspace. Ultraviolet radiant energy can thus have enhanced disinfecting by churning the feed so that microbes are exposed and killed by UV because suspended solids offer them no effective shade. 
         [0164]      FIG. 2  shows a closeup of the left side of the workspace  11  in  FIG. 1 . The feed flow into the photobioreactor is shown at  46 , and the sink flow for light products to axial extraction out of the photobioreactor is shown at  47 , as well as the peripheral flow outward for heavy products  48 . The feed in the axial feed conduit  3  comes through the axial feed port  4  and enters the photobioreactor in the space underneath the baffle  5 , which is located between the bottom disk impeller  6  and the top disk impeller  7 . The feed flow is enhanced by vanes attached to the impellers, such as those shown in  FIGS. 7-15 . The vanes on the bottom impeller are indicated by  51 , the vanes on the baffle are at  52 , and the vanes on the upper impeller are shown at  53 . In this example, the baffle is assumed to be attached to the bottom disk impeller so they co-rotate, so the vane pattern of the vanes on the top of the baffle  52  will resemble the vanes on the bottom impeller  51 . 
         [0165]    An optional crossflow filter  54  inset into the bottom disk impeller can be used to remove fluid from a sludge in a fluid flow  55 , by making use of the force produced when the sludge is forced outward by centrifugal force while being squeezed by the pinch section  40  where the disks impellers have a narrower separation. The crossflow filter is a sintered metal or plastic screen, made flush to the interior surface of the disk impeller facing the workspace, and usually backed by a watertight plug to close it when it is not in use. This crossflow filter would be used for dewatering an algae sludge, with the disk impellers spinning much faster than they normally would for general algae growth. This faster rotation would tend to spin all of the algae outward from the workspace, to clear the way for a fresh batch. The dewatered algae sludge concentrate would then proceed outward into the pinch section  40 . 
         [0166]    A similar perforated opening gas vent  56   a  in the top disk impeller could be used to vent gases that would tend to accumulate in bubbles on its interior surface, and be swept out toward the periphery by the vanes. There would be a smaller net area of opening needed for the vent in this case. The vented gases should be monitored as to their composition, as part of the sensors which would monitor the condition of the feed in the workspace, measuring factors such as temperature, pH, density, nutrients and mass flow. 
         [0167]    Optional rugose ridges, such as  56  on the bottom impeller and  57  on the top impeller, can interrupt and constrict the outward flow  48  flow still further, causing pressure waves for osmotic shock at low speed or cavitation in fluids at high speed, as another way to transform the feed. These rugose ridges are described more fully in the discussion of  FIG. 5 . 
         [0168]      FIG. 3  shows a cross section closeup of the flows in the workspace. Next to each disk impeller  6  and  7  is a boundary layer  60 , characterized by a laminar flow  61  of the feed, some of which flows inward  62  to the shear layer  63 , which is located between the boundary layers. The shear layer contains a branching area-preserving network of vortices, with larger vortices toward the axis collecting the products of smaller vortices toward the periphery. The outer region of a typical vortex is shown at  64 , with its flow at  65 . Heavier products are spun out by amplified centrifugal force in the photobioreactor and migrate outward, first to the outer regions of the vortex and then to the boundary layer in an outward flow  66 . Meanwhile, the inner part of the vortex  67  has a flow  68  that collects the lighter parts, which are drawn inward toward the axis of rotation in a sink flow  69 . 
         [0169]    In the case of algae, under normal growth conditions the boundary layers would comprise mostly a water, CO 2  and nutrient feed, and the algae would concentrate in the vortices in the shear layer, where they would divide and grow. 
         [0170]      FIG. 4  shows an orthogonal cross section of the workspace, with a flow pattern of vortices, where the clockwise flow of a larger vortex  70  may be surrounded by counterclockwise flows  71  in the overall turbulence pattern. Both of these types of vortices contribute to the overall sink flow network by creating centrifugal separation  72  of the feed. For algae, the rotations of the algae in these vortices would expose all of them more completely to the light coming through the disk impellers, while at the same time the centrifugal separation  72  would strip out the products with a lower specific gravity, such as extruded lipids, into the sink flow. Recent work by VG Energy has shown how the lipid trigger can be manipulated to make algae overproduce and extrude lipids, instead of storing them in their bodies. If these extruded lipids can be continuously stripped away from the algae, they will not contaminate the environment of the algae and inhibit their growth. The live algae are typically kept apart by electrical repulsion, and kept buoyant by their motility as well as internal gas vacuoles or gas bubbles on their membranes, but as they die they would become less buoyant and would migrate into the heavier products flow outward. Thus, the dead algae would tend to collect on the periphery of the reactor, and the lighter products such as lipids would be continuously collected in the axial sink flow. 
         [0171]    If the goal of the photobioreactor is the mass production of algae, then the excess algae be extruded at the periphery, leaving a constantly growing and dividing stock in the workspace. This separation could be assisted by the clumping of algae by autoflocculation. As the algae consume the carbon dioxide being introduced axially, the outer regions of the workspace grow to have a higher pH, which, together with flocculants in the solution such as calcium carbonates and calcium phosphates, cause the algae to clump together. This increases the centrifugal force on the clumps, and causes them to spin outward to the periphery. Using ports in the disk impellers for introducing flocculant chemicals directly into the solution at a given radial distance from the axis of rotation  10  can allow more precise control of this process. 
         [0172]    In  FIG. 5  is a top view of the bottom impeller  73 , which has a clockwise rotation  9 . It can be made of any suitable material, such as plastic, glass, ceramic, metal or any practical material. In the case of transparent disk impellers for algae, the material used should not block the most beneficial wavelengths. There are, in this example, four vanes  74 ,  75 ,  76  and  77 , attached to the impeller and made of a suitable material, shaped in this case according to a spiral. The edge of the baffle  5  is indicated at  78 . In the center, at the axis of rotation, is the apex of the screw feed conveyor  79 , which preferably should be conical to produce a more lateral feed underneath the baffle. 
         [0173]    The vanes form crossing intersections such as  80  with the corresponding but inverted vanes on the underside of top impeller, such as  81 , which is here seen as if looking down through the top impeller at a moment when the vanes are crossing. These moving intersections form a rhythmical flow along eight well-defined intersection axes:  82 ,  83 ,  84 ,  85 ,  86 ,  87 ,  88  and  89 . This rhythmical flow is shown in  FIGS. 7-15 . The mass flow along these eight axes is the basis for the organized turbulence of the flow of the shear layer between the disks. This mass flow through the boundary layers also prevents the formation of biofilm which can coat the disk impellers and block light. The vanes push the feed outward as the disk impellers turn, and the intersection points moving outward along the intersection axes form moving zones of increased shear and vorticity which reinforce the sink flow moving inward toward the axis of rotation. 
         [0174]    A pattern of rugose ridges  90  can be part of the peripheral section, as also seen in  FIG. 2 . They are designed to intersect the corresponding rugose ridges from the top impeller, such as shown by a sample at  91 . These rugose ridges are for causing osmotic pressure waves at low speeds or cavitation in liquids at high speeds, or to aid in the comminution of a more solid feed. In the case of algae, the rugose ridges would produce osmotic shock, and, at high speed, cavitation bubbles in the water, which would explode the algae cell membranes and release the contents, allowing a better interaction with digestive enzymes for more complete recovery of any stored lipids. 
         [0175]    The output deflector wall is shown at  36 . This barrier, which can be made part of the impeller or separately attached, deflects the processed heavy products downward into the heavy products outlets  13 , which are here shown partially covered because of the overhang of the output deflector wall  36 . The drive shield wall is shown at  35 . This wall is actually attached to the top disk impeller, but is added here for clarity. A gas vent  92  and a drive shield wall brace  93  are also shown. The drive shield wall brace  93  aids in the attachment of the drive shield wall to the top disk impeller. If a similar brace and attachment is also built into the disk impeller for the output deflector wall  36 , then the disk impeller design can be made to be interchangeable; usable for either the top or the bottom disk impeller. 
         [0176]    The optional annular crossflow filter inset into the bottom disk impeller is shown at  54 , which can be used to remove fluid from a sludge as discussed and shown in cross section in  FIG. 2 . A fuller description of this annular crossflow filter in a radial counterflow reactor can be found in the applicant&#39;s U.S. Pat. No. 7,757,866 entitled “Rotary Annular Crossflow Filter, Degasser and Sludge Thickener.” 
         [0177]    At the periphery of the disk, a drive track  30  engages the gear teeth of the drive wheel  29  which is driven by a motor  28 , or a sleeper wheel such as  33  which has a sleeper wheel support  34 . The drive can be a gear drive, a belt drive, a chain drive, or a friction drive, as needed for the application requirements, including noise, speed, and torque. 
         [0178]      FIG. 6  shows a side view cross section of the bottom disk impeller  73  of  FIG. 5 , drawn to the same scale, as also shown in  FIG. 1 . The bottom disk impeller  6  has an axial feed conduit  3  and an axial feed port  4  where the feed enters underneath the baffle  5 . A motor  28  drives a drive wheel  29  which engages a drive track  30  to rotate the disk impeller  6  around the axis of rotation  10 , stabilized by sleeper wheels such as  33  and other supports such as sleeper wheel support  34  and a base support  27 . The heavy products exhaust port is shown at  13 . The disk impeller vanes  51  and the baffle vanes  52  as well as the crossflow filter  54  are also shown in  FIG. 2 . In the peripheral pinch section b are the rugose ridges  56 . Further toward the periphery are the output deflector wall  36  and the drive shield wall  35  with optional gas vents  92 . A drive shield wall brace  93  can be built into a generic disk impeller design to enable attachment of the disk shield wall to the top disk impeller. 
         [0179]      FIGS. 7-15  show the successive rotation positions of a set of four straight vanes on two counter-rotating disk impellers. Each figure represents a rotation of 10°, so they make a repeating cycle of 90°. The direction of rotation for the top disk impeller is at  8 , and the direction of rotation for the bottom disk impeller is shown at  9 . The location of the edge of the baffle is at  78 . A straight vane on the bottom disk impeller is shown at  96 , and a straight vane on the top disk impeller is at  97 . The successive positions for these vanes are shown in each figure, and the parts representative of the top disk impeller are shown with dashed lines. The intersection points of the vanes form eight radial axes, such as at  82 , which are the organizing axes for the sink flow. 
       Liquid Impellers 
       [0180]      FIGS. 18-19  show another example of a photobioreactor, featuring liquid impellers, which is especially useful for aquaculture and for UV disinfection.  FIG. 18  shows a top view of an array of jets to create a moving liquid disk impeller. Preferably this array is static, and only the liquid moves. The liquid is fed through a network of supply pipes. An example of a main supply pipe is shown at  101 , and  102  shows a branch supply pipe. An example of a liquid jet nozzle is at  103 . When liquid such as water is forced through this nozzle, it makes a jet area of water pressure  104  which, in combination with the flow from the other jets, creates an overall direction of flow  105  for the liquid layer, forming a liquid impeller disk. Preferably the jets should be in a planar arrangement, parallel to the surface of the water, and the jet nozzles are configured to spray a pattern which spreads more horizontally than vertically, to fill in the liquid impeller layer more completely and to keep it from becoming too thick. 
         [0181]    In addition to the supply pipes spraying into the liquid impellers, preferably there are also drain pipes. Drain inlets  106  feed into drain pipes  107  which lead back to a central drain  108 , which is distinct from the central supply pipe  109 . An axial exhaust pipe  110  takes out the sink flow products from the workspace. Support frame members  111  keep the pipes and jets from becoming distorted or out of place, and support floats  112  can relieve their weight. A peripheral wall  113  sets a boundary for the photobioreactor. 
         [0182]      FIG. 19  shows a cross section of two liquid impellers in the photobioreactor. The top liquid impeller  114  is created by jets from fluid such as water carried by main supply pipes such as at  101 , fed by a central supply flow  119 , creating an overall direction of flow  8 . In this case the upper boundary of the upper impeller is equal to the surface of the water. The bottom liquid impeller  115  is created by a similar array of pipes and jets, but pointing in the opposite direction, so as to produce an opposite direction of rotation  9  in the liquid impeller. Oppositely flowing turbulence  116  extending from the boundary layer into the shear layer in the workspace  11  creates a vortex network, with a sink flow of lighter products  17  being drawn into the central exhaust, while a flow of heavier products  15  flows from the periphery. A network of drain pipes  107  is preferably also present, leading into a central drain outlet  120 . A support float  112  helps manage the weight of the pipes, and the peripheral wall is shown at  113 . The liquid impellers can be used within a cylindrical tank or in a pond or lake which is larger than the width of the array of jets. One liquid impeller can also be used by itself at some distance below the surface, allowing the surface of the water and the liquid impeller to define the workspace. 
         [0183]    Radiant energy  41  is applied in this case by sunlight shining through the transparent water to encourage growth in the workspace. The liquid impellers can introduce nutrients such as food and beneficial gases into the workspace, by first dissolving these components into the water carried in through the supply pipes. The drain pipes can help draw out any waste products that find their way into the liquid impeller layer. The liquid impellers can also help regulate temperature in the workspace. For example, on a hot day, the upper impeller layer can be supplied with colder water, which will diffuse downward and cool the workspace. 
         [0184]    Aquaculture can include the cultivation of many different types of organisms, such as algae, shrimp, fish, oysters, and seaweed, either alone or in combination. The younger or weaker organisms would be more likely to be passively carried by the vortices created in the workspace, but the larger or stronger mobile organisms would be able to be actively able to swim into the disk impellers themselves, where they could have more direct access to food in the liquid impeller layer, with less competition than in the workspace. This self-separation of organisms could aid in the harvesting of the more mature individuals. 
       Biochar Processer 
       [0185]    Another example of a radial counterflow reactor with applied radiant energy is used for the processing of biomass for biochar, bio-oil, and combustible gas. In this case the feed  1  is different, but the general design of  FIG. 1  is the same, with the applied energy  41  absorbed into the feed  42  in the workspace  11  being infrared or heat energy heating the disk impellers  6 ,  7 , which are made of a refractory material that can resist heat, pressure and wear. The heating can be done by external means, such as flames heating a portion of the disk impeller as it passes, or internal means, such as heating coils built into the rotating disk impellers. The combustible gas output of the process can be burned to help supply this heat. 
         [0186]    A wide variety of cellulosic biomass feed stocks can be used, including wood chips, sawdust, switchgrass, bagasse, corn stover, plant cuttings, seaweed, and algae cake, and other biodegradable waste. The feed should be ground before it is input into the bioreactor to enable it to be churned by the turbulence in the workspace, and dried to reduce the energy needed to convert it. 
         [0187]    The biomass feedstock is churned and heated in the workspace  11  of the radial counterflow reactor, where it undergoes thermal decomposition in an oxygen-starved environment, forming biochar and gaseous products that comprise bio-oil and syngas. The pyrolysis of triglycerides and other organic compounds in the feedstock forms carboxylic acids, alkans, alkenes, aromatics, and other volatile compounds that can be condensed into bio-oil. Syngas is comprised of hydrogen and carbon monoxide. In addition, there will be steam and other gaseous. The biochar may contain potash and other compounds, depending on the feed. More applied energy  41  applied to the bioreactor for higher temperatures will create more gasification and less char. The infrared energy can come from heated disk impellers, or heated sand mixed with the feed, such as is used by BTG-BTL in their design for a rotating cone reactor. The pyrolysis can be fast pyrolysis, for a higher proportion of bio-oil output, or slow pyrolysis, for more biochar out. The present design for a bioreactor will be more efficient in the processing because of the high turbulence and rapid stripping of the light products from the feed. 
         [0188]    In the workspace  11 , the pyrolysis of triglycerides and other organic compounds in the feedstock forms carboxylic acids, alkans, alkenes, aromatics, and other volatile compounds, which comprise the light products stream  99 . Producer gas, a more complete gasification product created by even more heat and pressure, is comprised of carbon monoxide, steam, hydrogen and other compounds, and is useful for producing fuel and chemicals. The biochar product is useful for soil remediation and carbon sequestration, and also can be burned as a fuel. 
         [0189]      FIGS. 16 and 17  shows examples of sets of flows for a radial counterflow reactor, showing the outline of a disk impeller  7 , the axial exhaust port  18 , the heavy products flow  98  toward the periphery, and the inward light products sink flow  99 , as separated by a vortex network  100 . In  FIG. 16 , for a radial counterflow algae photobioreactor, the heavy products flow  98  comprises heavy products with more specific gravity than water in the feed, such as algogenic organic matter (AOM), senescent algae, and flocculated algae. The light flows would be the components with less specific gravity, such as gases, including oxygen and excess CO 2  and extruded lipids. Increasing the rotation speed of the disk impellers as well as the suction at the axial exhaust port  18  would increase the radial counterflow separation effects, to make healthy excess algae that is crowding the workspace also move outward. When the central suction is decreased and the rotation speed is increased, the net effect is to clear out the workspace, for cleaning or restocking. In  FIG. 17 , the heavy products for a biochar reactor would include biochar, and the light products would include bio-oil, volatile organic compounds (VOCs) and steam. 
         [0190]    The radial counterflow reactor with applied radiant energy of this disclosure has here been described for its use as an algae churn, in aquaculture and as a biochar oven. However, it will be appreciated by those skilled in the art that a continuous separator of this type, making use of applied energy to transform the feed while simultaneously separating the byproducts, can find use in other applications, such as chemical engineering, refining, and food processing. 
         [0191]    For example, radiant energy in radial counterflow can aid in drying, cleaning or processing solids while simultaneously extracting vapors and gases, or other continuous processing with centrifugal force and heating. It can also be of use in classifying, separating and assorting solids with heat treatment, or with separating or classifying gases and liquids by induced swirl and rotational hydrodynamic extraction. The radial counterflow reactor with applied radiant energy is also of use as a pump where one fluid is pumped by contact or entrainment with another within a rotary impeller, or by using one or more jets. 
         [0192]    While the embodiments of the present invention have been particularly shown and described above, it will be understood by one of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Technology Classification (CPC): 8