Aquaculture net cleaning system

Abstract

An apparatus for cleaning aquaculture nets underwater. The appartus employs a propeller housing with a centrally disposed axis with a plurality of propeller blades extending therefrom. An outer perimeter ring secured to an outer tip of each propeller blade with a plurality of knuckles secured to the outer perimeter ring. Each knuckle including a curved surface constructed and arranged to strike the aquaculture net upon rotation of the blades for removal of growth by impact and shaking of the aquaculture net.

Claims

1. An aquaculture net cleaning system comprising: at least one propeller housing with a centrally disposed hub with a plurality of blades extending therefrom; an outer perimeter ring secured to an outer tip of each said blade; a plurality of triangular shaped rigid knuckles having a forward surface and a trailing surface forming two opposed convex edges and a base secured to said outer perimeter ring, wherein each said forward surface is constructed and arranged to be forcefully presented to an aquaculture net upon rotation of said blades; wherein rotation of said blades provides thrust for positioning said knuckles against the aquaculture net positioned underwater whereby said knuckles remove fouling from the aquaculture net by causing the aquaculture net to ride up said forward surface of said knuckle and down said trailing surface of said knuckle and upon the aquaculture net traversing said knuckle the aquaculture net returns to position allowing for removal of growth by impact and shaking the aquaculture net.

2. The aquaculture net cleaning system according to claim 1 wherein angles measured from tangent to said forward surface from said base of said knuckle changes from 20 degrees to over 45 degrees.

3. The aquaculture net cleaning system according to claim 1 wherein said forward surface approximates a radius of over 2 inches.

4. The aquaculture net cleaning system according to claim 1 wherein said forward surface of said knuckle is about 30 degrees from a centerline of said base wherein about 30% of the power to said propeller system is directed to said blades and about 70% to said knuckles.

5. The aquaculture net cleaning system according to claim 1 wherein said forward surface of the knuckle is over 66 degrees measured from perpendicular to the propeller rim and tangent to said forward surface.

6. The aquaculture net cleaning system according to claim 5 wherein said forward surface is unsymmetrical and said trailing surface is relieved to allow faster net recovery.

7. The aquaculture net cleaning system according to claim 1 wherein said forward surface has about a 22 degree angle from a centerline of said base with a 0.927 cosine angle and a 0.374 sine angle said forward surface is calculated by a cosine angle parallel to a net and a sine angle perpendicular to the net.

8. The aquaculture net cleaning system according to claim 1 wherein said forward surface has about a 30 degree angle from a centerline of said base with a 0.866 cosine angle and a 0.5 sine angle of said forward surface is calculated by a cosine angle parallel to a net and a sine angle perpendicular to the net.

9. The aquaculture net cleaning system according to claim 1 wherein said forward surface has about a 65 degree angle from a centerline of said base with a 0.406 cosine angle and a 0.906 sine angle of said forward surface is calculated by a cosine angle parallel to a net and a sine angle perpendicular to the net.

10. The aquaculture net cleaning system according to claim 1 wherein said forward surface is constructed and arranged to apply about 7.6 lbs. of force parallel to the aquaculture net and about 4.4 lbs. of force perpendicular to the aquaculture net.

11. The aquaculture net cleaning system according to claim 1 wherein said knuckles are not symmetrical.

12. The aquaculture net cleaning system according to claim 1 wherein said knuckles have a length of less than 2 inches and are removably fastened to said perimeter ring.

13. The aquaculture net cleaning system according to claim 1 wherein said hub is elastomeric with said plurality of blades attached to said elastomeric hub.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of the aquaculture net cleaning system propeller housing with knuckles secure to a perimeter ring;

(2) FIG. 2 is an enlarged view of a portion of FIG. 1;

(3) FIG. 3 is a front plane view of a first embodiment knuckle;

(4) FIG. 4 is a perspective view of FIG. 3;

(5) FIG. 5 is a front plane view of a second embodiment knuckle;

(6) FIG. 6 is a perspective view of FIG. 5;

(7) FIG. 7 is a front plane view of a third embodiment knuckle;

(8) FIG. 8 is a perspective view of FIG. 7;

(9) FIG. 9 is a front plane view of a fourth embodiment knuckle;

(10) FIG. 10 is a perspective view of FIG. 9;

(11) FIG. 11 is an end view of FIG. 9;

(12) FIG. 12 is a front plane view of a fifth embodiment;

(13) FIG. 13 is perspective view of 12;

(14) FIG. 14 is exploded view of the elastomeric hub; and

(15) FIG. 15 is a cut away view of the elastomeric hub.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(16) A detailed embodiment of the instant invention is disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific functional and structural details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representation basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

(17) FIGS. 1 and 2 depict an aquaculture net cleaning system technology comprising a propeller housing with a centrally disposed elastomeric hub 12 with a plurality of blades 14 extending from the elastomeric hub 12 to an outer tip 16 of each blade. An outer perimeter ring 18 is secured to the outer tip 16 of each blade 14. A knuckle 20 is secured to the outer perimeter ring 18. Each knuckle 20 includes a curved surface 22 constructed and arranged to be forcefully presented to the aquaculture net upon rotation of the blade 14 for removal of growth by impact and shaking of the aquaculture net.

(18) Lower tensioned net loads with the described technology is analogous to a base guitar where strings move easily and far when compared to standard guitar or banjo where movement is very low with the same force and movement is far less. The knuckle design of the instant invention is designed to play the standard guitar versus the base guitar. The cleaning of nets with the new knuckle design results from impacting hard growth by cleaning knuckles, friction on net twine and aggressive shaking of the net to remove soft growth. The energy required to do this without net damage is a function of the net or twine tension and the angle of the moving knuckle, the speed and the distance pushed.

(19) The Lindgren disclosure WO 2016/183274 A1 works well with low tension nets. However, with high tension large mesh nets the net is much more difficult to shake and move distant from normal positions. The forces are a geometric function being the sine or cosine of the angle of the knuckle to compare the forces paralleled to the face of the net versus perpendicular to the face of the net. To reduce the force on the net and torque requirement of the equipment and clean well requires a curved surface to change the angle as the net is moved to keep the forces more constant than can be achieved with a straight surface.

(20) FIGS. 3 and 4 depict a preferred knuckle 20 having a curved surface 22 on a leading edge and compound angle trailing edge 24. Apertures 26 and 28 allow for receipt of fasteners 30 and 32. The centerline 34 is illustrated as about 0.375″ from the center of the apertures 26, 28. The knuckle 20 is more net friendly, reduces power requirement and improves equipment life. This knuckle 40 embodiment having a length of about 2.086″. The design is symmetrical to operate in clockwise or counterclockwise direction and can be reversed if worn.

(21) FIGS. 5 and 6 depict a knuckle 40 having a symmetrical edge surfaces 42, 44 with a centerline 46 illustrated as about 0.375″ from the center of the apertures 48, 50. This knuckle 40 embodiment having a length of about 1.802″. FIGS. 7 and 8 depict a knuckle 60 having non symmetrical edge surfaces 62 and 64. Edge surface 62 having an angle of about 25 degrees, rear edge surface 64 having a compound angle slightly more than 65 degrees. FIGS. 9-11 depict a knuckle 70 having symmetrical edge surfaces 72, 74 of about 60 degrees. The length is about 2.0″ and the curvature of the knuckle provides a radius of about 9.75. Excluding friction the forces on the net. FIGS. 12 and 13 depict a knuckle 80 with a rapidly sloping curved edge 82 and rearward curved edge 84. This embodiment provides faster net strand return that can improve cleaning on very tight nets at the expense of an efficient reverse that is can be used to move more easily or untangle kelp, ropes and other fouling.

(22) Forces from the cleaning knuckle can be compared by calculating as follows:

(23) Parallel to net face=force (cosine angle)

(24) Perpendicular to net face=force (sine angle)

(25) TABLE-US-00001 TABLE 1 Angle from centerline Cosine Sine 22 degrees .927 .374 30 degrees .866 .5 65 degrees .406 .906

(26) Maximum torque for a propeller in this type of net cleaner is 50 to 100 ft. lbs. with approximately 30% of the power delivered to the propeller blades 70 lbs. force is remaining for typically 8 cleaning knuckles or 8.75 lbs. per knuckle. Single angle knuckles typically have an angle of around 30 degrees from centerline.

(27) TABLE-US-00002 TABLE 2 Single angle Force parallel Force perpendicular 30 degrees to net to net Curved angle 4″ radius 7.6 4.4 Lower curve 22 deg. 8.1 3.3 Upper curve 65 deg. 3.6 8.4

(28) Shown in Table 2 is how dramatically the forces parallel and perpendicular the net change as the knuckle moves on the net strand. The curved angle knuckle can provide high forces to move the aquaculture net parallel to the net face and then shift to high push perpendicular to the net for maximum movement with less torque. This is not possible with a single angle.

(29) The existing designs were symmetrical commonly with an acute angle to centerline of approximately 30 degrees. Because of the low angle on the downstream side recovery of the twine is fast and also shakes off fouling. With the advance invention of the curved knuckle the downstream side can have inhibited return recovery at low rotational speeds causing less cleaning power of the twine not quickly returning to position rapidly. The solution is a more acute or straight angle on the downstream side. Sometimes the propellers are run in reverse to untangle or reposition the cleaning head. The downstream angle must not be so acute to prevent reverse rotation of above below 20 degrees. When in reverse the propellers quickly move the cleaning head off the net and only a small angle is required. The current invention increases efficiency and rotational speeds for better cleaning.

(30) Referring to FIG. 14, illustrated is an exploded view of the elastomeric hub 12 which forms a flexible drive coupling to facilitate the use of the knuckles. The elastomeric hub operates as a shock absorber to lessen impact damage to the knuckles when removing aged barnacles or other hard growth that would otherwise case spike loads. The elastomeric hub 12 consists of a driver 84 having a plurality of splined shaped formations 86, 88 positioned around the diameter of the driver 84 on each side of a centrally disposed guide wall 90. In the preferred embodiment, the driver 84 is formed from a rigid material such as aluminum, delrin or the like. A elastomeric body 92 is over molded to the driver 84 wherein the splined shaped formations 86, 88 maintain the elastomeric body 92 from rotating separately from the driver 84. Similarly, the guide wall 90 which extends outwardly from the splined formations 86, 88 prevents the elastomeric body 92 from detaching from the driver 84. In the preferred embodiment the elastomeric body 92 is a urethane elastomer. While the inner surface 94 of the elastomeric body 92 is molded to the splined formations 86, 88, and outer surface 96 has a plurality of concave sections formed from valleys 98 and peaks 99 along the outer surface 92. The elastomeric hub 92 is constructed and arranged to prevent spike loads in a rotational direction and parallel to the rotational axis of the propeller simultaneously. The elastomeric body 92 forms a flexible element preferably with a durometer between 70 and 90 A shore hardness, the I.D. and O.D. of the flexible element and mating surface are splined. A base 100 of the hub 12 has an inner surface 104 having concave sockets 106 for receipt of the valleys 98 and peaks 99 of the elastomeric body 92. The outer shell preferably constructed from aluminum for support of the blades 14 and outer perimeter ring 18. A coupling ring 108 secures the driver 84 within the base 100, the coupling ring 108 may be secured along a groove 110 formed along an edge of the base 100. A protective shield 112 is securable to the base 100 having a lip 114 for securement along edge 116 of the base.

(31) All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.

(32) The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more” or “at least one.” The term “about” means, in general, the stated value plus or minus 5%. The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.”

(33) The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements, possesses those one or more steps or elements, but is not limited to possessing only those one or more elements.

(34) One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.