Patent Application
20120148416
The present invention relates generally to the field of paddlewheel apparatus for moving water, and more particularly, to a high efficiency paddlewheel apparatus including an alternating set of fixed, alternating crisscrossed flanged curved paddles supported by at least two, and preferably three, hubs coupled to a motor driven shaft, wherein the paddle design provides improved rigidity, energy transfer and reduced drag as compared to conventional paddlewheel apparatus.
Various species of algae are now being commercially grown for a variety of uses including bio-fuel feedstock and health supplements, among others. Algae are desirable in that they can be grown year round under the right temperature conditions, have relatively short generation times, and require readily available and inexpensive nutrients for growth, such as sunlight, water and carbon dioxide. Algae are also desirable in that they can be grown in adverse conditions, such as saline and brackish water.
Algae are typically grown in open bio-ponds and shallow raceways in which it is necessary to create a current to prevent the algae from becoming stagnant. It is also necessary to prevent algae from remaining at the surface of the pond in which sunlight exposure may be too great, or remaining at the bottom of the pond in which there is too little sunlight exposure, both of which are adverse to growth. Conventionally, to address these issues, paddlewheels have been deployed within ponds and raceways to introduce a current. These conventional paddlewheel designs, however, suffer from several disadvantages, some of which include utilizing large flat paddles that require large amounts of energy to move through the water, paddle structures that are cupped in the direction of rotation and retain water as the paddles leave the water, and paddlewheels that are fixed in height in relation to the pond floor, thus causing cavitation and the raising of liners in lined ponds.
Accordingly, to overcome the disadvantages of conventional paddlewheel designs, and to improve the creation of current in a bio-pond or raceway, a paddlewheel apparatus and methods of operation are provided that include an energy efficient paddle design, height adjustability, sensor control to optimize paddlewheel rotational speed and construction including materials adapted to withstand both fresh and salt water conditions.
In one aspect, a paddlewheel apparatus is provided herein including a lightweight, rigid construction with a multi-functional energy efficient paddle design that reduces drag, increases the amount of water moved and does not collect water as the paddles leave the water. The overall paddlewheel can be raised and lowered to accommodate sudden increases in pond water levels.
In another aspect, the paddlewheel apparatus may be provided for creating and maintaining an active current in a bio-pond or raceway. The apparatus creates and maintains a bidirectional (i.e., left and right actions) to its forward moving water current. This novel design accomplishes this by using a crisscrossed scissor blade layout attached to circular hubs on the axle of the paddlewheel. Each paddle sweeps the water in the channel in a forward alternating movement pattern that moves the water first left and then right. Additionally, the design positions the paddles to enter the water first from each end of the paddle, which causes the paddles to cut into the water at an angle. This effect provides for a very smooth entry, resulting in a minimal resistance (i.e., splash back) and greater wheel efficiency. This smooth entry into the water by the paddles also creates less of a shock to the water, substantially preventing injury to the algae. One effect of the paddlewheel design is the production of a three dimensional eddy current effect in all corners of the channel. In contrast, traditional paddlewheels create a linear current direction. The scissor wheel, because of its left right push design, along with the non-cupping action of its paddles, creates a complex matrix eddy effect in the water channel that reduces current dead zones normally found in algae raceways channels.
Because of this multi-directional movement, it is not necessary to have the paddles the full depth of the pond water to create a large singular push to reach all of the corners of the pond channel. Thus, this design allows for smaller surface area of the paddle apparatus. The smaller paddle surface area advantageously results in a high-efficiency apparatus due to the low cavitation effect of the paddles upon their entry into the water, and the smaller surface area of the paddles not having to push the water in a linear flow, thus the wheel can be operated with less energy and consequently lower operating costs. The reduced surface area design further has a lower construction costs.
To achieve the foregoing and other aspects and advantages of the present invention, in one embodiment a paddlewheel apparatus is provided herein including a paddlewheel axle, spaced apart annular wheel hubs mechanically coupled to and locked in rotation with the paddlewheel axle, and elongated, crisscrossed flanged paddles each being arranged symmetrically angled with respect to a longitudinal axis of the paddlewheel axle, and being cooperatively supported by the wheel hubs. The crisscrossed paddles are arranged at predetermined intervals around the circumference of the annular wheel hubs and are spaced apart from the paddlewheel axle.
In one particular embodiment, the paddles are flanged or curved, also referred to herein as “scissor shaped,” and are continuous and are bent or otherwise formed to define an inner paddle portion for providing rigidity to the paddle and for moving water, and an outer paddle portion positioned at an angle with respect to the inner paddle portion for reducing paddle drag. The inner and outer paddle portions together define a cup-shape that opens in the direction opposite the rotational direction of the paddlewheel apparatus so as not collect water therein as each paddle leaves the water.
In smaller channel applications, where the width and or the depth of the water is less, a single scissor blade design may be employed.
The wheel hubs may have defined slots in which the inner paddles are received and secured therein.
The paddlewheel apparatus may further include fixed supports for supporting the position of the paddlewheel axle. The apparatus may further include variable height dual platforms operable to simultaneously raise and lower the entire paddlewheel assemble including a motor coupled to the paddlewheel axle through a gearbox for rotating the paddlewheel axle. The spaced apart annular wheel hubs are mechanically coupled to and locked in rotation with the paddlewheel axle. The crisscrossed, elongated, scissor-shaped paddles are each cooperatively supported on the outer portion of the wheel hubs.
The paddlewheel apparatus may include a control system that receives an input from a sensor module regarding at least one of liquid density and water current, and controls the rotational speed of the paddlewheel based upon the output.
In another embodiment, a method of creating current in a bio-pond is achieved with a paddlewheel apparatus including a paddlewheel axle supported about each end by first and second supports, at least two spaced apart annular wheel hubs mechanically coupled to and locked in rotation with the paddlewheel axle, a plurality of crisscrossed scissor blades circumferentially arranged around the annular wheels hubs and spaced apart from the paddlewheel axle, and a motor for rotating the paddlewheel axle through a gearbox. Because of the zigzag design of the paddles, a complex matrix of currents are created, causing a left and right current along with an up and down current. The complex matrix of currents ensures better overall pond circulation, eliminating traditional no-flow voids or dead spots in open pond designs. The apparatus may further include a sensor module including at least one of a liquid density sensor and a water current sensor, and a motor speed regulator for regulating the voltage supplied to the motor. The method further includes increasing or decreasing a rotational speed of the paddlewheel axle in response to the output of the sensor module by regulating the voltage supplied to the motor.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein. It is to be understood that both the foregoing general description and the following detailed description present various embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification.
These and other features, aspects and advantages of the present invention are better understood when the following detailed description of the invention is read with reference to the accompanying figures, in which:
The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which exemplary embodiments of the invention are shown. However, the invention may be embodied in many different forms and should not be construed as limited to the representative embodiments set forth herein. The exemplary embodiments are provided so that this disclosure will be both thorough and complete, and will fully convey the scope of the invention and enable one of ordinary skill in the art to make, use and practice the invention. Like reference numbers refer to like elements throughout the various figures.
Referring to the figures, various embodiments and deployments of an energy efficient paddlewheel apparatus are shown and described. The paddlewheel apparatus may be constructed from any materials, and is preferably constructed from lightweight materials adapted for long term use in both fresh water and saltwater applications without component degradation. Suitable paddlewheel material examples include, but are not limited to, stainless steel, fiberglass and aluminum. Various components of the apparatus may be mechanically coupled or fastened together using any number of conventional methods, and the specific methods described herein are not intended to limit the invention.
Referring to
The paddlewheel 22 further includes at least one annular wheel hub 50 for supporting a plurality of paddles 52. Referring specifically to
The wheel hubs 50 define slots 56 in which portions of the paddles 52 are received within and secured. The paddles 52 may be secured using any conventional fastener or by welding. Preferable fasteners are preferably low profile to reduce drag in the water. The paddles 52 are secured in predetermined intervals about the circumference of the wheel hubs with their longitudinal axis arranged generally parallel to the longitudinal axis 30 of the paddlewheel axle 28, and with the general lateral axis arranged generally perpendicular to a tangent of the wheel hub. The paddles preferably define a width less than the radius of the wheel hubs 50, and thus are spaced apart from the paddlewheel axle 28 providing an internal material void in the paddle to reduce rotational mass, prevent the paddles from collecting water and reducing materials.
Each paddle 52 is elongated and tri-curved, also referred to herein as “Z-shaped,” and is preferably constructed from a continuous piece of material bent, formed or molded to define the proper shape. Each paddle 52 defines an inner paddle portion 56 positioned closest to the axle 28 for providing rigidity to the paddle, a center paddle portion 58 positioned at an angle with respect to the inner paddle portion 56 for moving water, and an outer paddle portion 60 positioned furthest from the axle 28 and at an angle with respect to the center paddle portion 58 for reducing paddle drag.
The tri-curve paddle 52 is specifically designed for moving algae in culturing ponds. The inner paddle portion 56 is designed to add rigidity to the paddle 52 allowing a small amount of paddle area while the bend increases the structural support allowing for fewer wheel hub support sections along long paddle length distances. The center paddle portion 58 is the key water moving section of the paddle 52. The outer paddle portion 60 transfers the final energy of the sweep of the paddle 52 in the pond to continue along its final path. Thus, the paddle shape aids in energy transfer, unlike conventional flat or cupped paddles in which the final sweep of the paddle creates a drag on the system and a load on the motor.
Referring to
Referring to
The apparatus further includes a height adjustment mechanism including holes defined through the mounting plate 48 for allowing threaded rods 70 to pass therethrough. Thus, the threaded rods 70 are secured about one end to the axle 28, and secured about their other end to the supports 32 and 34. The height adjustment mechanism may include a simple nut and bolt locking arrangement on the threaded rod to the gearbox/motor mounting plate 48, and the paddlewheel portion has the ability to be raised and lowered to adjust the position of the paddles 52 with respect to the pond floor 66. The motor/gearbox unit 46 is preferably positioned above the surface of the water. The ability to raise or lower the paddles 52 in relation to the pond floor is important for efficient water flow, minimizing cavitation, and creating a non-turbuent mixing. Further, in applications including a pond liner, the ability to position the paddles away from the liner prevents it from being pulled up.
Referring again to
In operation, the motor speed regulator 72 is set to a predetermined pond current water velocity for the given growth cycle of an algae species. The motor speed regulator 72 maintains the current speed by a variety of measurements including monitoring the density of the water (i.e., the level of growth of the algae strands), and water current speed. This information is used to determine the correct rotational speed of the paddles. Less energy is required when the water density is low and the current high.
The paddlewheel apparatus further optionally includes a carbon dioxide exhaust tube 76 for injecting carbon dioxide into the water to saturate the water with gas. The tube 76 is preferably mounted along the back edge of the water entry side onto the paddlewheel support structure. The length of the tube 76 may correspond to the length of the paddles 52. The placement of the injection tube 76 at the paddle exit point optimizes the infusion of carbon dioxide while not mixing oxygen into the system caused by the cavitation of the paddles in the water. Carbon dioxide is a key feedstock nutrient to promote the growth of algae.
Referring to
In response to the output of the motor speed regulator 72, the motor 24, preferably an electric motor known to those skilled in the art, turns the reduction gearbox 26, which in turn rotates the paddlewheel axle 28 and paddles 52. The paddlewheel apparatus works on the principle of pushing the water along the raceway 78 by the force of the tri-curved paddles 52 sweeping across the entire width w of the shallow water in the pond. The diameter of the paddlewheel, the number of paddles, and the required speed of the rotation of the paddles is determined by the specific strand of algae being grown, the height of the water that holds the algae, and the support wall or brim height to insure the motor and gear box are above the flood plane of the pond.
Referring to
The paddlewheel 102 includes at least two annular wheel hubs 114 for supporting a plurality of paddles 116. Referring specifically to
The wheel hubs 114 each define slots 118 in which portions of the paddles 116 are received within and secured. The paddles 116 may be secured using any conventional fastener or by welding. The paddles 116 are circumferentially spaced apart around the wheel hubs 114. The paddles each preferably define a width less than the radius of the wheel hubs 114, and thus are spaced radially outwardly from the paddlewheel axle 106, providing an internal material void in the paddle to reduce rotational mass, prevent the paddles from collecting water and reducing materials.
Each paddle 116 is elongated, mounted at an angle, and arced across the hubs 114, also referred to herein as a “scissor paddle design.” Each paddle 116 may be constructed from a continuous piece of material bent, formed or molded to define the predetermined shape. Each paddle 116 defines an inner paddle portion 120 for providing rigidity to the paddle and resisting larger objects, and an outer paddle portion 122 arranged at an angle to the inner paddle portion 120 for moving water. The outer paddle portion 122 is positioned furthest from the axle 106 at an angle with respect to the inner paddle portion 120 for reducing paddle drag. The angle of the each paddle 116 and its respective inner and outer portions 120, 122 in relation to its mounting on the hubs 114 is variable and may be determined based upon application. Each paddle 116 is preferably arranged on the paddlewheel 100 such that the “cup” formed by the inner and outer portions 120, 122 opens in the direction facing away from the direction of contact with the water so that the paddles do not hold water.
The paddles 116 are arranged crisscrossed on the paddlewheel, meaning that the paddles are arranged back and forth and at an angle around the circumference of the wheel hubs 114. As shown in
The crisscrossed paddles 116 are specifically designed for moving algae in culturing ponds. The inner paddle portion 120 is designed to add rigidity to the paddle, allowing a small amount of paddle area while the bend increases the structural support allowing for fewer wheel hub support sections along long paddle length distances. The outer paddle portion 122 transfers the final energy of the sweep of the paddle in the pond to continue along its final path. Thus, the paddle shape aids in energy transfer, unlike conventional flat or cupped paddles in which the final sweep of the paddle creates a drag on the system and a load on the motor. The angled design of the paddles 116 allow for easy entry and exit from the water, and further advantageously prevent algae clusters from being picked up as the paddles travel along the circular path.
The apparatus provides for height adjustment based upon application. The motor/gearbox is preferably positioned just above the surface of the water. The ability to raise and lower the paddles 116 in relation to the pond floor is important for efficient water flow, minimizing paddle entry cavitation. In one exemplary installation, the top of the paddle may be positioned at the surface of the pond. Height adjustment and motor speed may be achieved according to the embodiment discussed above.
Referring specifically to
Referring to
While paddlewheel apparatus have been described with reference to specific embodiments and examples, it is envisioned that various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.
This application is a continuation-in-part application claiming priority to U.S. application Ser. No. 12/402,001 filed Mar. 11, 2009, the contents of which is incorporated by reference herein. This application further claims priority to U.S. Provisional Application No. 61/548,387 filed Oct. 18, 2011, the contents of which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61548387 | Oct 2011 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12402001 | Mar 2009 | US |
| Child | 13401186 | US |
