CLIAMS:- ,TagSPECI:TECHNICAL FIELD
Embodiments of the present disclosure generally relate to a mixing device and an apparatus employing the same. The device is adapted for mixing purposes so as to maintain solid mass in a suspended state within the apparatus.

BACKGROUND

With the industrial evolution, different types of bodies of liquid are increasingly being employed for purposes including, but not limited to, agitation of dispersible and insoluble solid substances, cultivation of organisms (and particularly, photosynthetic microorganisms), fishery, and wastewater treatment. However, solid mass in a body of liquid required to be kept in a suspended state to avert settling thereof for achieving best results. Specifically, the solid mass is required to be maintained in a suspended state in the body of liquid for achieving one or more objectives, including, but are not limited to, uniform exposure of the solid mass to light, uniform distribution of the solid mass within the body of liquid, and uniform mixing of the solid mass with other components (such as nutrients, other chemical entities etc.) within the body of liquid and the like. To achieve the above one or more objectives, turbulence needs to be generated in the body of liquid to avoid settling of the solid mass.

In conventional practice, the turbulence is generated by providing solid surface substantially flat agitators such as but not limited to a paddlewheel adapted to rotate in a predetermined direction/ along an axis including but not limited to a horizontal axis and a semi-horizontal axis; a stirrer adapted to rotate in a predetermined direction/ along an axis including but not limiting to a vertical axis and a semi-vertical axis; and a baffle fixed or moving in a predetermined manner including but not limited to a periodic motion and a rotational motion. Typically, all of such conventional solid-surface agitators are either partially or fully submerged in a body of liquid, and are adapted to move or rotate in respective, aforesaid manners for mixing purposes. However, these conventional solid surface agitators, which are substantially flat, require high energy for creating turbulence. Specifically, the conventional agitators with substantially flat solid surface encounter a high resistance provided by various components in the body of liquid, thereby resulting in a high energy requirement for the operation and/ or movement thereof for generating turbulence.. For large-scale applications it is imperative that the energy consumption in mixing is kept at minimum and yet optimal results are achieved. In addition to the high energy consumption, utilization of conventional agitators may lead to problems including but not limited to, inefficient mixing based on vortices formed behind the agitators and settling of solid mass at areas not within the reach of the agitators that have limited dimensions (such as diameters etc.), cavitation and raising of liners in lined bodies of liquid etc.

The term substantially flat agitator as used in this disclosure may be defined as an apparatus which shakes or stirs the components including, but not limited to, water and gases in a body of liquid. The agitators are predominantly two dimensions in shape with a shorter third dimension that is provided for mechanical integrity. Further, the term substantially flat agitator may be defined as agitators with flattened surface which may or may not be 100% planar, which may include curved surface or angular surface, and uneven surface, in other words it is not completely planar.

The term body of liquid as used herein above and below may relate to a natural body of liquid (such as a natural pond) or man-made body of liquid (such as a pilot/ laboratory scale liquid containing vessel which can be a part of any further system) which is independent of dimension and/or shape thereof. Specifically, the body of liquid may comprises components including, but not limiting to, solid mass, liquid and gases. Further, the term ‘solid mass’ may relate to any dispersible solid organic/inorganic chemicals, waste materials and recyclable materials; biomass; organisms; ingredients such as nutrients and the like.

As an example, efficient cultivation of photosynthetic organism in a body of liquid such as a reservoir/ a pond which is filled with liquid such as water, and nutrients is dependent on exposure of photosynthetic organism to sufficient light, which is necessary for growth of photosynthetic organisms. Traditionally, photosynthetic organisms are grown in raceway ponds filled with water in which turbulences are accomplished by conventional mechanical devices such as agitators including, but not limiting to, paddlewheel and the substantially flat agitators having solid surface. As explained above the conventional agitators encounter higher resistance for operation and/ or movement thereof inside the body of liquid, thereby resulting in high energy consumption which in turn increases cost of cultivation of photosynthetic organism.

Limitations of existing conventional substantially flat agitators having solid surfaces such as but not limiting to, paddlewheel, stirrers and baffles are illustrated with the help of cultivation of photosynthetic organism (one of the field of applications of the flat agitators) as an example. However, such example should not be construed as only application. Thus, person skilled in the art can envisage various other applications where such limitation exists.

In light of foregoing discussion, there exists a need to develop an improved mixing device such as agitator configured to be employed in bodies of liquid to overcome the limitations as stated above.

SUMMARY:

In one non-limiting embodiment of the present disclosure, there is provided a mixing device and an apparatus employing at least one such mixing device. The apparatus comprises a body of liquid of a predetermined shape and size for holding various components including but not limited to solid mass. Specifically, one or more mixing devices of a predetermined shape and size conforming to the shape and size of the body of liquid are adapted to be movably disposed within the body of liquid.

The mixing device comprises a plurality of perforations to accomplish turbulence of the components in the body of liquid.

In an embodiment of the present disclosure, the apparatus is used for cultivation purposes, such as culturing/ cultivation of organisms, and more specifically, for culturing photosynthetic organisms. Further, the components may include solid mass such as photosynthetic organisms and other ingredients such as water and nutrients as required for culturing of the organisms.

In an embodiment of the present disclosure, the mixing device is configured to have at least one movement that is horizontal and translational either in straight line or any curvature in the body of liquid.

In an embodiment of the present disclosure, the perforations of the mixing device are distributed substantially on an entire surface of the mixing device.

In an embodiment of the present disclosure, the body of liquid is natural body of liquid or man-made body of liquid with varying dimensions. The man-made body of liquid includes but is not limited to, a container, a reactor, a bio-reactor, a photo-bioreactor, and a pond. The body of liquid may be configured to have a shape including but not limited to a rectangular shape, V-notch shape, a circular shape and square shape. Further, in one embodiment the shape of the mixing device conforms to the shape of the body of liquid.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS:

FIG. 1 illustrates a schematic view of an apparatus employing a mixing device of the present disclosure, in accordance with an embodiment of the present disclosure.

FIG. 2 illustrates a schematic section of the apparatus employing the mixing device, in accordance with another embodiment of the present disclosure.

FIGS. 3a-3c illustrate schematic views of a motorized mechanism used to move one or more mixing devices in a body of liquid in accordance with an embodiment of the present disclosure.

DESCRIPTION:

To overcome the limitations stated in the background, the present disclosure provides a mixing device also hereinafter interchangeably referred to as ‘agitator’, and an apparatus employing one or more such mixing devices for use in applications including, but not limited to, cultivation of organisms; fishery; and wastewater treatment. The apparatus comprises a body of liquid employed with one or more mixing devices adapted for mixing components including but not limited to solid mass present in the body of liquid to maintain the solid mass in a suspended state within the body of liquid.

The mixing device of the present disclosure is provided with a plurality of perforations in order to be configured as an agitator with a porous surface. In one embodiment, the perforations are distributed substantially on entire surface of the mixing device. In another embodiment, the perforations may be distributed on a portion of the surface of the mixing device. The perforations are provided on the mixing device to accomplish turbulence of the components including, but not limited to, solid mass in the body of liquid by allowing the flow of components through perforations when the mixing device operates and/ or is moved inside the body of liquid. Since, the perforations allow the flow of components in the body of liquid through the mixing device, less resistance is provided to the operation of the mixing device as imparted by the components in the body of liquid. This aids in consumption of less power for operating the mixing device. Further, percentage free area of the mixing device which is relative to ratio of the area of perforations on the mixing device and total cross-sectional area of the mixing device may be optimized based on mixing requirement. Specifically, higher the free area, lower is the resistance to the movement of the components in the body of liquid, thereby involving less power consumption for moving the mixing device. The term ‘free area’ as used herein above and below relates to area available for liquid movement through the mixing device. Perforation size for a fixed free area may also be optimized for improving mixing quality. Specifically, size of vortices formed behind the mixing device may be determined based on the perforation size for a fixed free area for improving quality of mixing.

Further, due to the provision of the plurality of perforations in the mixing device, a more complex turbulence of the solid mass can be generated in the body of liquid than the one expected out of a solid block without perforations. Further, perforation on the mixing device also aids in saving energy because of lesser resistance for the operation (liquid being allowed to pass through) of the mixing device. In addition, the size and arrangement of the perforations are provided in the mixing device such a way that it reduces entanglement, agglomeration or adhesion of the dispersible components in and around the perforations and/or on the solid surface.

Further, the mixing device is configured to optionally move in a predetermined direction and/ or manner including but not limited to, a horizontal translation movement in either a straight line or curvature in at least one axis including, but not limited to, horizontal axis, vertical axis, or any other axis based on the requirements. Further, the mixing device is adapted to move within the body of liquid using a mechanism, including, but not limited to, a sliding mechanism, a motorized mechanism, and an actuator mechanism. Without departing from the scope of the present disclosure, any other mechanism may be employed for moving the mixing device within the body of liquid. The movement of the mixing device within the body of liquid additionally creates a complex turbulence, thereby resulting in mixing of the components including, but not limited to, solid mass in the body of liquid. Due to provision of mixing, the solid particles in the body of liquid suspend in the body of liquid.

In one non-limiting embodiment of the present disclosure, the turbulence is further generated by “planetary motion” for the mixing device/ agitator in the body of liquid. The term planetary motion as used herein above may be defined as essentially having a horizontal, translational motion apart from/ irrespective of an axial motion, if any, around the vertical, horizontal or any other axis. In some embodiments, the axial motion can be avoided in order to reduce centrifugal precipitation or agglomeration.

The term mixing device as used in this disclosure preferably relates to a substantially flat agitator having a porous surface. The substantially flat agitator may not be limited to an agitator with a planar porous surface; a curved porous surface; an uneven porous surface; and an angular porous surface; and like. Further, the agitator may be a porous agitator having a configuration including but not limited to, a paddle wheel, a mixing plate, a baffle, a stirrer and the like. In an embodiment, the mixing plate referred herein above is a plate of predetermined shape such as but not limiting to a rectangular plate and a trapezoidal plate with perforations.

In an embodiment of the present disclosure, the mixing device and apparatus are more conducive to solid dispersants which has a reticular and/or lamellar rather than pure granular disposition.

In an embodiment of the present disclosure, the mixing device may be configured in a shape examples of which include, but are not limited to, a flat shape, a curvature shape, a tapered shape, an angular shape, or any other shape, or combinations thereof, which serves the purpose of the present disclosure. Further, the perforations provided on the mixing device are configured in a shape examples of which include, but are not limited to a circular shape, a rectangular shape, a triangular shape, a square, or any other shape, or combinations thereof, which serve the purpose of the present disclosure.

Further, the mixing device may be made up of a light-weight material such as a plastic material and a fiber reinforced plastic (FRP) material, which requires minimum power for operation and/ or movement thereof. In another embodiment, the mixing device may be configured in the form of a mesh or a net made of wires composed of materials such as a metallic material, a plastic material, a polymeric material, a combination thereof, and the like, for mixing. For example, the mixing device may be configured in the form of a net made of High-density polyethylene (HDPE). In yet another embodiment, the mixing device may be configured as either a perforated metal or a polymeric sheet. The aforesaid materials or configurations of the mixing device are only for exemplary purposes and need not be considered to be limiting to the scope of the present disclosure.

For better mixing, speed of motion of the mixing device may be optimized. Specifically, higher speed of motion for the mixing device ensures better mixing. The time lag between two successive visits of the mixing device at a same location of the body of liquid may be optimized/ designed based on the dimensions of the body of liquid, speed of motion of the mixing device and the number of mixing devices installed along a channel length/ width of the body of liquid.

Without departing from the scope of the present disclosure, the body of liquid may be of any shape and dimension as required for the purposes of the present disclosure. Further, the body of liquid may be made of materials such as cement, metals, glass, plastic and the like, which are known in the art, and with or without a liner material.

Henceforth the present disclosure is explained with the help of one or more exemplary embodiments. However such exemplary embodiments should not be construed as limitations of the present disclosure. The person skilled in the art can envisage various such embodiments without deviating from scope of the present disclosure.

As an exemplary embodiment of the present disclosure, the apparatus which is employed with the one or more mixing devices is used for cultivation of organisms such as photosynthetic organisms. The following explanation of FIG. 1 and FIG. 2 is directed to the cultivation apparatus of photosynthetic organisms including, but not limited to, algae.

FIG.1 is an exemplary embodiment of the present disclosure which illustrates a schematic view of photosynthetic organisms culturing apparatus (100) which is rectangular in shape and employs one or more mixing devices (102). The culturing apparatus (100) comprises a body of liquid (101) which is either a natural body of liquid (such as a natural pond) or man-made body of liquid (such as a pilot/ laboratory scale liquid containing vessel which can be a part of any further system). The mixing device (102) such as flat agitator having perforations, of a rectangular shape that conforms to the shape of the body of liquid (101) is movably disposed, and is either removably or non-removably fitted to a motorized mechanism [as shown in FIGS. 3a-c] within the body of liquid (101) with sufficient clearance from a bottom surface (101a) and side walls (101b) of the body of liquid (101). The mixing device (102) moves in predetermined direction and makes horizontal translational movement in either straight line along length or width of the body of liquid (101) or travels in curvature within the body of liquid (101). Thus, the movement of the mixing device (102) helps in mixing the photosynthetic organisms growth medium including but not limited to water and nutrients in the body of liquid (101) to facilitate periodic uniform exposure of photosynthetic organisms to light, uniform distribution of the photosynthetic organisms within the body of liquid (101), and uniform mixing of the photosynthetic organisms with other components (such as nutrients, other chemical entities etc.) within the body of liquid (101). Further, the mixing device (102) is provided with a plurality of perforations (102a) for efficient mixing. In one embodiment the perforations (102a) are distributed substantially on entire surface of the mixing device (102). When, the mixing device (102) travels in the body of liquid (101) turbulence is generated in the wake of the mixing device (102) due to presence of perforations (102a), which results in surface renewal of the solid mass such as but not limited to photosynthetic organisms, which is desired for appropriate photosynthetic organisms growth.

FIG. 2 is an exemplary embodiment of the present disclosure which illustrates a schematic view of a photosynthetic organisms culturing apparatus (100) having V-notch shape employing one or more mixing devices (102). The culturing apparatus (100) includes a body of liquid (101) having a V-notch shaped design for minimizing the energy consumption in mixing components in the body of liquid (101) for photosynthetic organisms cultivation. One or more mixing devices (102) of V-notch shape conforming to the shape of the body of liquid (101) is movably disposed, and is either removably or non removably fitted to a motorized mechanism [as shown in FIGS. 3a-c] in the body of liquid (101) with sufficient clearance from the bottom surface (101a) and the side walls (101b) of the body of liquid (101). The mixing device (102) moves in a predetermined direction and makes horizontal translational movement along length or width of the body of liquid (101) or travels in a curvature in the body of liquid (101). Without limitation to the scope of the disclosure, the mixing device (102) may make a non-translational movement within the body of liquid (101).

The movement of the mixing device (102) enables mixing the photosynthetic organisms growth medium including but not limited to water and nutrients in the body of liquid (101) to facilitate periodic uniform exposure of photosynthetic organisms to light, uniform distribution of the photosynthetic organisms within the body of liquid (101), and uniform mixing of the photosynthetic organisms with other components (such as nutrients, other chemical entities etc.) within the body of liquid (101). Further, the mixing device (102) is provided with a plurality of perforations (102a). In one embodiment the perforations (102a) are distributed substantially on entire surface of the mixing device (102). In yet another embodiment, the perforations (102a) may be distributed on a portion of the surface of the mixing device (102). When, the mixing device (102) travels in the body of liquid (101) turbulence is generated in the wake of the mixing device (102) due to presence of perforations (102a), which results in surface renewal of the solid mass such as but not limited to photosynthetic organisms which is desired for appropriate photosynthetic organisms growth. In an embodiment of the present disclosure, the number of mixing devices (102), speed of motion of the mixing devices (102), and porosity of the mixing devices (102) can be optimized using flow modeling and mixing analysis.

Further, the following aspects are envisioned for V-notch shaped design of the photosynthetic organisms’ cultivation apparatus (100) as advantageous over traditional raceway pond.

In one aspect, photosynthetic organisms' culturing apparatus (100) having V-notch cross-section has a smaller width compared to traditional raceway design for same amount of volume. Since the mixing energy consumption is largely decided by width of the body of liquid, the culturing apparatus (100) having V-notch shape would incur less energy consumption compared to traditional raceway pond. Further, the mixing device in translational (linear) motion creates vigorous turbulence in its wake promoting a greater localized mixing compared to poor global mixing in a traditional raceway design.

In another aspect, amount of liner material required for photosynthetic organisms culturing apparatus (100) having V-notch geometry would be lesser than that of a standard rectangular design. The potential liner material savings depends upon the specification of V-notch width and depth. It must be noted that the liner savings are compared for the same wetted-volume of rectangular design.

In further aspect, V-notch cross-section design of the body of liquid (101) offers a unique advantage for cleaning the body of liquid (101). The precipitates, dead- photosynthetic organisms biomass would naturally accumulate on the floor/ bottom surface (101a) and can be cleaned very easily compared to a rectangular design. This reduces the cost, since the cleaning of the body of liquid (101) is a very labor-intensive process.

In furthermore aspect, the depth of water in body of liquid (101) having V-notch shape is higher than that of the body of liquid (101) having rectangular shape. Thus, the body of liquid (101) having V-notch shape would save land area as compared to the body of liquid (101) having rectangular shape. Therefore, body of liquid (101) having V-notch shape would be especially useful where land availability is a critical issue.

In one embodiment, the body of liquid (101) having V-notch shape can be a V-shaped photo-bioreactor or any another closed system where such requirement of mixing exists.

FIGs. 3a-3c depict schematic views of an exemplary embodiment of the present disclosure which illustrates a motorized mechanism (M) used to move mixing devices (301) in a body of liquid (302). In the body of liquid (302), a supporting member (303) is provided in a predetermined location (such as at the center of the body of liquid (302) and along a width thereof), and a motorized mechanism (M) is provided on the supporting member (303) to move one or more mixing devices (301) which are either removably or non-removably fitted to the motorized mechanism (M), as depicted in FIG. 3b. The supporting member (303) may be configured as a mid-wall of the body of liquid (302). For the purpose of simplicity, the mixing devices (301) are shown without any perforation. However, it should be understood that the mixing devices (301) are similar to the mixing device (102) and may include appropriate number, size, shape and type of perforations as described earlier.

In an embodiment of the present disclosure, the supporting member (303) is provided substantially at the center of the body of liquid (302) and includes at least one of but not limited to a guide rail [not shown] and track. The motorized mechanism (M) is provided on the supporting member (303) for a movement thereof across the body of liquid (302). The motorized mechanism (M) comprises one or more wheels (304) connected to a base plate (305) mounted on the supporting member (303). The base plate (305) is configured to move on the supporting member (303) through the one or more wheels (304). Without limiting the scope of the present disclosure, the one or more wheels (304) may be configured to move over the supporting member (303) based on the configuration of the supporting member (303).

The base plate (305) is further supported on the supporting member (303) with one or more support wheels (310) joined to the base plate (305) through a support shaft (311) for moving the mixing devices (301) over the supporting member (303).

In alternate embodiments of the present disclosure, at least one of the one or more wheels (304), the one or more support wheels (310) or both may be provided for the movement of the mixing devices (301).

Further, at least one motor (306) is mounted on a base plate (305), and is connected to at least one of the one or more wheels (304) and the one or more support wheels (310) for moving the base plate (305). In an embodiment of the present disclosure, the motor (306) is an electric motor and is coupled to one or more of the one or more wheels (304) and the one or more support wheels (310) using at least one of a chain drive (307) and a belt drive [not shown]. For the use of the chain drive (307), a driven sprocket is provided on the one or more wheels (304) and a driving sprocket is provided on the electric motor (306), and a chain is coupled between the driven sprocket and the driving sprocket. The motorized mechanism (M) further comprises a battery (308) interfaced with the electric motor (306) for providing necessary power to the electric motor (306) to move the one or more wheels (304) and /or the one or more support wheels (310). A controller (309) is interfaced with the electric motor (306) to regulate the movement of the electric motor (306). In an embodiment of the present disclosure, a pair of mixing devices (301) is connected to either ends of the base plate (305), and the base plate (305) carries the mixing devices (301) to mix the components including, but not limited to, solid mass in the body of liquid (302) when the motorized mechanism (M) is actuated. The controller (309) may be operated from site of the body of liquid (302) or from a remote location.

In an alternate embodiment of the present disclosure, the mixing devices (301) are moved on the supporting member (303) inside the body of liquid (302) by a mechanism including, but not limited to, rack and pinion mechanism, a hydraulic actuator mechanism, a pneumatic actuator mechanism, or any other mechanism which serves the purpose without going beyond the scope of the present disclosure.

In an exemplary embodiment one can envisage having more than one supporting members (303) to facilitate movement of the mixing devices (301). This could be either to carry more weight of mixing devices (301) or to provide multiple paths/directions for the mixing devices (301) to move.

Equivalents:
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Referral Numerals:
Reference Number Description
100 Apparatus employed with mixing device
101 and 302 Body of liquid
101a Bottom surface of the body of liquid 101
101b Side walls of the body of liquid 101
102, 301 Mixing device
102a Perforations on the mixing device 102
303 Supporting member
304 Wheels
305 Base plate
306 Motor
307 Chain drive
308 Battery
309 Controller
310 Support wheels
311 Support shafts
M Motorized mechanism