Patent Application
20070029404
The invention relates to a sprinkler and, more particularly, to a nozzle and flow channel of a sprinkler configured to improve flow characteristics.
It is commonly known to use various designs of sprinklers and irrigation systems for various watering applications. Each of these applications typically requires consideration of an emission or flow rate for water distributed to the area, and a distance or area over which the water from a particular sprinkler is distributed. Some particularized applications for sprinkler and irrigations systems require further consideration.
As an example, watering golf courses requires consideration of a greater set of factors. Each of the sprinklers presents an unnatural obstacle that is preferably out of an area of normal play. That is, sprinklers are permanently located at various locations around a golf course. These locations are selected so that, in the normal course of play, most golf balls will avoid the sprinklers and covers placed thereover. As an irrigation network, of which the sprinklers are a part of, may be damaged by excessive weight being placed on the covers, the sprinkler locations are also selected to reduce the likelihood that golf carts are driven over them, as well as pedestrian or golf traffic in general.
Toward the same goal of allowing the sprinkler to be generally avoided by the patrons of a golf course, the number of sprinklers is selected to minimize their number and intrusiveness. However, a typical 18-hole golf course has fairways cumulatively totaling 7000 yards of linear distance or more, not to mention the breadth of the fairways, and areas bounding the fairways commonly known as the rough.
Covering the length and breadth requires distributing or throwing the water a sufficient distance from the sprinklers balanced against minimizing the number of sprinklers. The sprinklers are necessary to provide watering to a variety of verdure, flora and fauna, grass, trees and shrubs, ranging from the azaleas and dogwood trees of Augusta National golf course to the prickly gorse of The Old Course in St. Andrews, Scotland. Watering golf courses, and in particular the watering of fairways, has been performed with sprinklers directing water with a standard trajectory in the range of 20 to 30 degrees above horizontal, and the water is commonly distributed distances of 60 to 100 feet.
While irrigating a farm crop area, the land is generally clear of anything other than the crops. With golf courses, it is common to have trees spread around in an irregular manner, the trees having low-hanging branches. It is also common for golf courses to include other overhanging obstructions. To avoid these obstructions on a golf course, as described, a trajectory lower than the standard trajectory may be used. However, this shortens the distance to which the water can be distributed from the sprinklers. Shortening the distance, then, requires a greater number of sprinklers.
In order to lower the trajectory without increasing the number of sprinklers, a greater throw distance is required. To do so, the water pressure and flow may be increased. Though a higher velocity at the sprinkler nozzle exit is produced, in practice the stream tends to break apart and cause misting, resulting in an imprecise water stream distributed from the sprinkler.
Another issue with golf courses is the careful regulation of the water quantity distributed and the moisture of the various areas. These areas include the fairways, the rough, out-of-bounds, patches of trees or plants, and high and low-lying areas that are affected by run-off more predominantly than other areas. As the areas of a golf course can vary so widely, the irrigation needs of each individual area is specifically planned. Sprinklers are on timers, or automatic sensors may govern the activation and de-activation of various sprinklers.
Nature itself often attempts to wreak havoc on the carefully-designed watering plans. For the most part, the watering plans can be adjusted to compensate for these attempts. Unfortunately, wind is one condition for which it is difficult to plan or compensate. The golf course at Torrey Pines in San Diego, Calif., is located on a bluff overlooking the Pacific Ocean, while the Old Course in St. Andrews is across a beach from the North Sea. Each of these settings subjects their golf courses to a wide range of wind conditions.
Strong winds have a number of negative effects on watering from irrigation sprinklers. In all cases, the wind directs water streams propelled through the air in a downwind direction. In some cases, this results in inappropriate areas receiving water from the stream. In the upwind direction, the stream is unable to distribute water to the proper distances. A water stream under higher pressures, and thus more prone to misting into smaller water droplets, is also more susceptible to effects from the wind as there is an increase in the ratio of wind force on the surface of the droplets and the mass of the droplets.
A lower trajectory for the water stream is less susceptible to wind effects. Wind composed of air, like any other fluid flow, obeys what is known as the no-slip boundary condition. Therefore, the speed or velocity of the wind tends to be lower near the ground surface. In addition, ground structures such as buildings, fences, and trees, reduces the effects of wind close to the ground level.
In summary, there are a number of carefully considered balances in golf course irrigation. A high trajectory for the water stream allows greater distribution distance, but the stream is more susceptible to winds and may be interfered with by trees, for instance, located on the golf course, and a lower trajectory avoiding such obstacles reduces the distribution distance. While a higher-pressured water source may help increase distribution distance, the stream is, again, more susceptible to wind. The number of sprinklers may be increased, but a greater number of sprinklers means a greater number of obstacles to the golf course which can impact or affect the enjoyment of the course by golfers.
Accordingly, there has been a need for an improved sprinkler for efficiently irrigating golf courses or other like areas.
Referring initially to
The case is typically buried so that a top edge is proximate or flush with a top ground surface. When the sprinkler is activated, water from the water source flows into, and eventually through, the sprinkler. The pressure of the water in the sprinkler overcomes the bias of the spring to force the riser 16 and the sprinkler head 12 upward to an extended position above the ground surface. Water is then distributed from the nozzle member 100 in a selected radial pattern or sweep.
The pressure and flow of the water also provide the sprinkler head 12 with rotational power. As can be seen in
The motor 30 communicates with the sprinkler head 12 to effect rotation thereof. The motor 30 includes an output shaft 36 secured with the drive train so as to rotate with an output speed therefrom. The output shaft 36 has an upper end 36a secured with the sprinkler head 12 to rotate the sprinkler head 12 with the output speed.
The sprinkler head 12 rotates in a selected radial sweep to distribute water therefrom. The radial sweep is adjusted by a control rod 38 having a top end 40 including structure, such as slot 42, for rotatably adjusting the rod 38. The rod 38 further has a lower end 44 including structure, such as gear teeth 46, for cooperating with a control plate (not shown). The position of the control plate determines the radial sweep, such as between 0 degrees and 360 degrees.
The riser 16 includes a lower body portion 52 having a lower end 54 with which a screen 56 (
The case and riser 16 cooperate to prevent dirt or particulate matter from entering therebetween from above ground. The case defines a cavity (not shown) in which the riser 16 is received, and the cavity includes a seal (not shown) at an upper portion thereof. The riser 16 has an upper body portion 66 including a cylindrical portion 68 with an outer surface 68a that the seal is in sealing contact, regardless of the position of the riser 16 relative to the case. The seal thus prevents entry for sand, dirt or other particulate matter from entering the sprinkler 10 during operation and, particularly, as the riser 16 retracts when the sprinkler 10 is shut off.
The upper body portion 66 of the riser 16 also directs water to the sprinkler head 12. The upper body portion 66 has an interior conical portion 72 angled inwardly as the water flows upwardly therethrough. The conical portion 72 has an upper opening 74 having a radius R1 through which the water flows to the sprinkler head 12.
The sprinkler head 12 has a body 50 rotatably supported by the riser 16. A cavity 78 is defined between the inwardly angled conical portion 72 and the cylindrical portion 68. The sprinkler head body 50 includes a lower cylindrical portion 80 positioned around an exterior surface 72a of the conical portion 72 and within an interior surface 68b of the cylindrical portion 68. As can be seen in
The output shaft 36 rotates the sprinkler head 12 on the riser 16. The body 50 includes radial ribs 81 joined about a central longitudinal axis of the sprinkler 10 by a hub 82. The hub 82 includes an axially-aligned keyhole 84 with an irregular shape for mating with the output shaft 36. Therefore, the rotation of the output shaft 36 effects co-rotation of the hub 82, the body 50, and the sprinkler head 12.
The output shaft 36 also secures and retains the body 50 on the riser 16. The output shaft 36 has an upper end 86 extending through the keyhole 84. A securement (not shown) that is larger than the keyhole 84 is secured with, such as by threading, the output shaft upper end 86 so that the body 50 and, consequently, the sprinkler head 12 is secured to the output shaft 36 while being rotatable relative to the riser 16.
Water flows through the riser conical portion 72, into the sprinkler head body 50, and between the ribs 81. The water flow is then channeled through the sprinkler head 12 and emitted from the nozzle member 100. More specifically, the water flow between the ribs 81 is channeled by the flow channel member 110, which focuses the water flow through a grid 102 located at the flow channel member 110, and is emitted from the nozzle member 100.
With reference to
The water flows between the ribs 130 and into the cap 126 for emission from a nozzle member 132. The cap 126 is generally cylindrical such that it has a cylindrical wall 134 and a top wall 136 orthogonal to the cylindrical wall 134. In general, the cylindrical and top walls 134, 136 form a right angle therebetween, such as at 138. The water flows into a cavity 140 defined by the cylindrical and top walls 134, 136 and, then, is forced through the nozzle member 132.
The nozzle member 132 is secured with and extends through an opening 142 defined by the cap 126. The nozzle member 132 includes a cylindrical feed portion 150 extending into the cavity 140 and towards the water flow. Within the feed portion 150 is a grid 152 which assists in collimating the water flow. The water passes through the grid 152 and exits through a nozzle 154 formed in the nozzle member 132. Specifically, the nozzle 154 is frustoconically-shaped having a larger inlet radius R2 than exit radius R3.
As water flows into the cavity 140 of the prior art sprinkler head 120, there is significant pressure or head loss. The flow of water within the sprinkler head 120 is generally uncontrolled. The head loss limits the performance of the prior art sprinkler head 120. For instance, the nozzle 154 is typically given an output trajectory between 20 and 30 degrees, and is typically fed with a high water pressure and flow rate, in order to achieve desirable throw distances in the range of 60-100 feet.
As discussed above, it is preferable to operate a sprinkler at a lower trajectory, which requires increasing the water pressure and flow rate to the prior art sprinkler head 120. With a nozzle trajectory of 12 degrees, the prior art sprinkler head 120 is generally capable of throwing water 55-60 feet for flow rates between 24 and 28 gallons per minute. As another more specific example, the prior art sprinkler 120 with a nozzle trajectory at 10 degrees and 70 psi requires 19.7 gallons per minute of flow to throw the water 52 feet.
High water high pressure and flow rates have a number of drawbacks. First, high pressure and flow rates place significant stress on the irrigation network, as well as each individual sprinkler. In addition, the nozzle member 132 does not effectively direct the water without causing misting, which is more susceptible to being blown or carried by wind away from the desired watering area.
The sprinkler head 12 described herein allows a greater throw distance at a lower flow rate. In order to do so, the sprinkler head 12 utilizes the flow channel member 110, cooperating with the nozzle member 100, for reducing head loss within the sprinkler head 12. As can be seen in
The flow channel 110 is supported by the body 50. The body 50 has an interior surface 180 including a circumferential shoulder 182 immediately above the ribs 81 and extending a short distance inwardly. The flow channel 110 has a generally circular bottom edge 184 resting on the shoulder 182 when the sprinkler head 12 is assembled.
Referring now to
Alternatively, the cap 170 may be secured with the body 50 in any other suitable manner, such as with an adhesive or welding, so that the posts 194 are not present. In this event, the cut-outs 202 would not be necessary, and a demarcation between the front and rear sections 190, 192 would be at along a line 212, as will be discussed below. The flow channel member 110 further defines a throughbore 203 for allowing the above-described control rod 38 to pass therethrough.
The cylindrical front section 190 rises from the bottom edge 184 a relatively short height 196 (
The cylindrical front section 190 terminates in an upper wall 198 for channeling the water received thereagainst. As water flows upwardly from the body 50, the water entering at the front area of the flow channel member 110 is guided by the upper wall 198 rearward and around the upper wall section 198 and further into the flow channel member 110. To ease this re-direction and to minimize head loss, the front section 190 and the upper wall section 198 form a curved or smoothly radiused edge 200 (
The cylindrical rear section 192 rises a distance from the bottom wall edge 184, though the distance varies around the circumferential extent of the cylindrical rear section 192. More specifically, the cylindrical rear section 192 transitions into a tapered section 210. The rear section 192 and tapered section 210 are joined along an arced line or portion 212. With reference to
As noted above, the flow channel member 110 reduces the head loss experienced by water as it flows through the sprinkler head 12 generally and, more particularly, through the cap 170. In general, the tapered section 210 allows for a smooth transition between the generally vertically flowing and collimated water through the sprinkler head 12 and the nozzle member 100 emitting the water in an exit trajectory, angle β above horizontal (
The tapered section 210 is generally a combination of a tapered tube and an elbow pipe to define a flow channel 220 through the tapered section 210. Consequently, the tapered section 210 is generally arcuately shaped in the direction of water flow, such as along line 250, discussed below, as well as in directions transverse to the direction of water flow and circumferentially around the water flow. As seen in
As seen in
The outlet 224 is sized to correspond to a nozzle 230 formed in the nozzle member 100. As can be seen in
As stated above, the preferred flow channel member 110 is generally similar to a combination of an elbow pipe and a tapered tube. For instance, the tapered section 210 angles forward from the cylindrical rear section 192, and tapers inward towards the outlet 224. As the upper wall section 198 curves upward, it joins with an outlet wall 242, as can be seen in
Generally, the flow channel member 110 reduces head loss and channels the water into the nozzle member 100. It is known that a smooth or gradual change of direction for flowing fluid results in lower head loss than does a sharp change in direction. It is also known that constriction of fluid flow results in a head loss. Accordingly, the design of the flow channel member 110 may be enhanced through the use of smoother transitions such as rounded edges and tapered surfaces, as opposed to sharp transitions. One aspect to note is that increasing the curve of a sharply turned portion may produce a head loss from constriction of the flow path that is greater than the head loss benefit achieved by increasing the curve.
The preferred flow channel member 110 balances smoothing of contours for the flow path 220 with resulting constriction that optimizes the flow path 220 for minimal head loss. For instance, the line 212 between the tapered section 210 and the cylindrical rear section 190 creates a relatively sharp contour for the water to flow over. Complete elimination of this line 212, in which the height 213 is zero, however would result in the inlet 222 being horizontal and generally coincident with the bottom edge 184. In such an instance, the water flow would experience less head loss through the region where the line 212 would otherwise be; however, this results in a narrowing of the flow path 220 that increases the head loss in a greater amount than the amount of head loss saved by the smooth contour.
The height 213 is selected to balance these factors. In general, any contouring of the flow path 220 provides a performance benefit. As seen in
As discussed above, the tapered section 210 transitions between the outlet wall 242, the upper wall section 198, and the rear wall section 192 along the line 212. As can be seen in
The height 213 determines where the intersection point 215 would be formed, in terms of position and angle α between the line 212 and the plane of the bottom edge 184. More specifically, the height 213 determines a radius of curvature R4 (
The line 212 is formed at the transition from the cylindrical shape of the lower cylindrical portion 186 and the tapered elbow pipe shape of the tapered section 210. Therefore, increasing the radius of curvature R4 correspondingly generally increases a radius of curvature along other portions of the tapered section. Thus, the line 212 between the tapered section 210 and the cylindrical portion 186 will shift upward so that the intersection point 215 at which the line 212 crosses the horizontal plane with the bottom surface 184 will correspondingly shift rearward, towards the rear-most point 211. Therefore, angle α will increase for a greater height 213. Conversely, lowering the height 213 is achieved by decreasing the radius of curvature for portions of the tapered section 210, thereby constricting the passage 220 through the tapered section 210 while reducing the sharpness of the transition along boundary 212″. Thus, the intersection point 215 moves forward, towards the front cylindrical wall portion 190, decreasing the angle α.
With reference to
More specifically, the flow channel member 110 defines a number of openings for various construction purposes. The flow channel member 110 includes the opening 203 for the control rod 38, and includes the cut-outs 202 for the posts 194 for attaching the cap 170 via fasteners or screws. Each of these is permitted to leak, and is not fashioned as to be sealed. Accordingly, a relatively small portion of the water flowing into the flow channel member 110 from the body 50 leaks outside of the flow channel member 110.
This designed leakage supplies water to the short and intermediate nozzles 260, 262. The flow channel member 100 serves to divide the cavity 176 into the flow path 220 through the flow channel member 100 and a cavity 264 (
With reference to
For the flow channel member 300, the angle α has been decreased to zero degrees. The flow channel member 300 includes an outlet 314, which preferably receives therein a grid substantially similar to grid 102. The radius of curvature for the flow channel member 300 is decreased to provide for the angle α of zero degrees. Accordingly, the constriction on water flow through the tapered section 310 is increased, in comparison to the above-discussed flow channel member 100. However, the flow channel member 300 does not have a transition line such as the above-discussed transition line 212.
In further comparison with the flow channel member 100, the flow channel member 300 has a top wall 318 joining with a front cylindrical wall section 320 to direct flow around to a nozzle opening 322. The top wall 318 joins with an outlet wall 324 to form a relatively smooth path for the water flow through the region proximate and below the nozzle opening. The front wall section 320, the top wall 318, and outlet wall 324 thus provide a smoother path for water to flow along, thus reducing head loss.
The sprinkler head 12 utilizing the flow channel members 100, 300 benefit from improved watering and flow characteristics. For instance, the sprinkler head 12 may be operated at 70 psi having a nozzle trajectory of 10 degrees. When used with the flow channel member 100 having an angle α of 12 degrees, the sprinkler head 12 delivers water a distance of 64 feet with a flow rate of 19.2 gallons per minute. When used with the flow channel member 300, angle α being zero degrees, water is emitted a distance of 60 feet with a flow rate of 19.2 gallons per minute. Under the same parameters, the prior art sprinkler 120 throws water only 52 feet and requires a flow rate of 19.7 gallons per minute. In order to achieve 64 feet of throw distance, the prior art sprinkler 120 requires a flow rate of 20.4 gallons per minute and a trajectory of 25 degrees. In a representative embodiment, the lower cylindrical wall 186 has an approximate inner diameter of 1.185 inches at the entrance to the inlet 222, the outlet wall 242 is positioned on a horizontal line approximately 0.757 inches from the rear wall portion 192, and the diameter of the outlet 224 is approximately 0.599 inches.
While the invention has been described with respect to specific examples, including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described devices and methods that fall within the spirit and scope of the invention as set forth in the appended claims.
