Patent Grant
10399095
The invention relates generally to the field of bath and shower systems. More specifically, the invention relates to vorticity generating elements and atomizing elements, also called splash vanes, and shower heads incorporating the same.
Shower heads generally include a plurality of nozzles to provide a shower of water droplets over a large area of a user's body. It is generally desired that a shower head provide the following: efficient wetting of maximum body, sufficient pressure to wash soap suds off the body, a comfortable feel of the droplet spray on impact with the body, and conservation of water.
Spray nozzles with generic vanes are widely used in the agricultural field for spreading water, fertilizers, and pesticides. Such spraying is often performed over large tracts of land, and farmers desire to use conservative methods to dispense the fertilizers and pesticides in an efficient and economical manner. Agricultural spray nozzles use atomization techniques to break up the flow of fluids into smaller droplets, enabling the coverage of wider areas of farm land. When the droplet is too small, for instance less than 150 microns in diameter, it then becomes a misty fog and drifts away from the area that needed to be treated. Indeed one needs to be careful not to be anywhere close to such drifting, fogging, and clouding conditions.
Spray nozzles with vanes are also used widely for tank cleaning, auto wash facilities, driveway cleaning and other high-pressure applications. For such applications a higher impact force of the droplets from the liquid jet on the contact surface that is being cleaned becomes significantly important.
Spray nozzles and vanes developed for the above applications fall short of meeting the needs of bath systems, and there is clear need for an improved system that addresses this complex and challenging problem. The small droplet sizes preferred in agricultural spraying and the high droplet impact forces of pressure cleaning systems are inappropriate for shower systems. In addition, the temperature characteristics of the droplet spray are critical in showering applications, but generally have no relevance to agriculture and cleaning applications.
To apply such technology to shower heads, one has to be cognizant of the heat transfer characteristics of the water droplets and their dependence on the size of the droplets. The larger the droplet the more the mass and higher the heat flux it can hold (heat flux, Q, is defined as the amount of heat contained in the mass of material Q=mass*specific heat of the fluid*Delta T, where Delta T is the temperature difference between the inlet temperature of the jet and the ambient temperature). As the water exits from the shower head it exchanges heat with the surrounding ambient air by convection from its surface area and the bather by conduction. The larger the surface area of the droplet the greater the heat loss. Also, as a large droplet is split into large number of small droplets, the total surface area of all such smaller droplets increases, resulting in larger heat loss through convection at their surfaces. The smaller the droplet the smaller the heat flux in it and larger the heat loss. Also, the larger the droplet size the higher the heat flux in the droplet. In other words, for the same amount of flow from a shower head, larger droplets retain more heat than smaller droplets and cover lesser area to wash, whereas smaller droplets cover larger area to wash and loses more heat than the larger droplets. These two opposing properties of the droplet sizes require careful attention in selecting the droplet size to achieve the satisfactory performance from the shower head.
The vane for a shower head described herein provides a splash spray capable of delivering a warm and comfortable shower experience while also conserving water. Embodiments of the atomizing and vortex generating element, also referred to herein as a splash vane or vane, can generate a class of conic fluid jets varying from full cone fluid jets to hollow cone fluid jets with various dispersion angles of the exit jets. Embodiments provided give the designer a unique capability to design conic fluid jets with variable droplet density and diameter that can be used in many applications meeting the challenging property requirements including the heat transfer requirements. In this invention the methodology adopted comprises a qualitative investigation to find a splash vane mechanism that yields the desired characteristics of a droplet and its heat transfer properties for shower head applications. The splash vane geometry should be small enough to be accommodated in a small splash nozzle body needed to conserve the water.
The splash spray shower head, also referred to as a shower head, includes a shower head body with a fluid inlet connected to a supply tank which holds and distributes the fluids to a plurality of splash nozzles. The splash nozzles, also referred to as nozzles, are held by a nozzle holding plate, which may be an integral part of the shower head. A plurality of splash vanes are inserted in nozzles, and may be used with retaining rings. The splash vane has a substantially cylindrical body with a central longitudinal axis extending from a top face to a bottom face. A vane blocker is centered about the central longitudinal axis, as has a cross-sectional profile orthogonal to the central longitudinal axis. The shape of the solid body of the vane blocker includes the cross-sectional profile rotated about the central longitudinal axis in a helical path from the top face to the bottom face, and forms a plurality of helical flow boundary walls. These flow boundary walls define a plurality of flow paths. Each flow path has a vane opening at both the top face and the bottom face so that fluid may flow from the top face to the bottom face in a swirling path around the central longitudinal axis.
Fluid enters the shower head at its inlet and is distributed to the plurality of nozzles that are held in a water tight manner by the nozzle holding plate. A vigorous forced rotational motion is imparted to fluid entering the nozzles by the plurality of swirling flow paths of the splash vane. Fluid exits the vane with a large vorticity coupled with high intensity turbulence. Fluid impinging on the inner walls of the nozzle undergoes atomization. These properties of vorticity, rotational motion, turbulence, and atomization cause the fluid to exit in a conical jet form with significant dispersion angles. Without the presence of the splash vanes, the fluid would have exited the nozzles in a string-like laminate form with no dispersion at all.
Referring initially to
Rotating ball swivel connector has a connecting end to main water supply 12, configured for connection to the water supply line in the household. The straight connector to swivel ball connector 1 of shower head body 3 is connected to connecting end to the shower head 13 of rotating ball swivel connector 11 in a secure fashion which provides the flexibility in positioning the shower head.
Splash nozzles 6 are each fitted with an atomizing and vortex generating element also known as turbulence and swirl generating splash vane 9. Nozzles 6 are securely fastened to nozzle holding plate 5 and positioned and configured to spray fluid through a plurality of holes in a bottom plate 7 of the shower head. Bottom plate 7 may be an integral part of the shower head body 3. The plurality of holes in the nozzle holding plate 5 and those in the bottom plate of shower head 7 are aligned to properly to insert and hold the splash nozzles securely to the nozzle holding plate 5. All parts of the assembled shower head are secured in a water tight fashion.
The shown embodiment includes five splash nozzles 6 and five splash vanes 9. Embodiments are presented wherein the splash vanes may or may not include a retaining ring 9. Several embodiments of splash nozzles and splash vanes can be arranged to serve the same purpose of this application. The embodiment of the shower head presented in this invention is very flexible and can be scaled to fit many a specific needs as a situation warrants. Notice this splash spray shower head is quite different from the conventional round bottomed shower heads where the water outlets, the nozzles, are usually placed in a symmetric circular manner. As seen in
With reference again to
Referring to
The design process and the performance of these the splash nozzle and splash vane are described below.
The Splash Nozzle
The splash nozzle 10 is a device that ejects liquid droplets in a spray form. The details of geometry and flow paths of an example splash nozzle 10 are shown in the
Fluid enters splash nozzle 10, with a splash vane 9 inserted in it (see, e.g.,
The splash nozzle 10, shown in
The inlet pressure of the fluid and the exit diameter 26 of the shower head splash nozzle control the flow rate from the splash nozzle and thereby the flow rate of the shower head. The splash vane, by virtue of its geometry and its position in the flow path of the fluid, controls the inlet and exit angles of the fluid flow, the turbulence levels of the flow, the atomization of the fluid in the splash nozzle, the dispersion angle of the fluid jet exiting the splash nozzle, and thereby the droplet size of the exiting fluid jet.
For the shower head to meet water conservation requirements, a splash nozzle that yields lower mass flow rates was designed. The estimated flow rates and the measured flow rates from such a splash nozzle are compared in
The splash vanes, by virtue of their geometry, impart rotational motion to the fluid in the nozzle. The rotational motion of the fluid imparted by the vane in the nozzle changes the flow properties of the exiting jet from a long cylindrical string-like laminate form to a conical shaped jet. Some of these conical forms comprise a full cone jet wherein at every cross section of the full conical jet is filled by the droplets. Other forms include hollow conical jets. The droplets from the hollow cone jets display a ring-like form where all the droplets exiting from the splash nozzle are concentrated at the periphery of the jet forming a dense ring of droplets with none in the middle of it.
The droplets from full cone jets are larger than those from hollow cone jets. As such, the hollow cone jets yield a greater number of droplets for a given mass flow of the jets and are capable of wetting a larger surface area for showering purposes compared to a full cone jet. In view of that a hollow cone nozzle was chosen to meet the goals set for the present invention.
The approach here is to define a variable geometric property of a splash vane and investigate qualitatively its influence on the flow properties like the dispersion angle of the flow from the splash nozzle and the droplet particle size. An option for the splash vane design comprising a variation of the inlet flow area of vane opening at entrance of the nozzle was chosen. Such an approach gives the designer an ability to control the flow at the vane inlet of the splash nozzle and investigate its influence on the flow properties of the exit jet like the dispersion angles of the jet, droplet heat transfer and impingement properties qualitatively.
Such designs not only control the inlet mass flow of water but also the angle of entrance and the exit angle of flow into the nozzle. Several splash vanes were designed with different vane opening areas and identical flow entrance and exit angles for the flow to enter and exit the splash nozzle. These splash vanes were inserted into identical splash nozzles and tested at a chosen design pressure of the shower head. A test bed shower head with plurality of holes to accommodate one to six splash nozzles at any given time was used. These test splash nozzles with designed splash vanes were installed in the test bed shower and tested to measure the dispersion angles of the exit jets. Such a test setup eliminates the deviations in the test conditions from one splash vane to the other.
Qualitative results of some of these tests at design pressure are presented in
These results indicate that the fluid jet dispersion angle widens with the decrease of the flow inlet area; thereby the inlet mass flow. It further shows that the large area ratio vanes yield full cone fluid jets whereas the smaller area ratio vanes resulted in hollow cone fluid jets. This is a significant finding as it indicates that with appropriate measurable changes to the geometry of the splash vanes in a systematic fashion (in this invention flow inlet areas were changed—this in turn changed the inlet mass flow through the vane opening) one can generate a class of jets varying from a full cone fluid jets to hollow cone fluid jets. The interesting feature here is that the geometry of the splash nozzle and its flow rates were unchanged while the character of the exit jet was dramatically changed from one class of jets to a significantly different class of another ones. These results strongly indicate that the hollow cone fluid jets are a subset of full cone fluid jets. Further tests indicated that increasing the swirl flow path rotation also yields hollow cone fluid jets. Implementation of such higher swirl flow path rotation lengthens the vane. With the aid of this information the designer can design the same class of splash vanes and splash nozzles to meet the desired requirements of their applications.
The splash vanes described herein were designed with the aid of the information from the above independent investigation. The splash vane embodiments shown in
11C show splash vane configuration plan views with two vane openings 50 at the top of the vane for the fluid entrance. A vane blocker 41, separates the two openings. The splash vane comprises a continuous flow boundary wall 42, encircling a solid body in the center of it. In this design the solid body is the vane blocker of the nozzle. The swirling flow paths 43, in the splash vane was created by rotating the vane blocker by a small angle around the vane axis 51 (the central longitudinal axis of the vane), of the splash vane and traversing it; up or down; simultaneously along the same axis. This process was repeated in a continuous circular manner from one angular position to another and connecting the corresponding points or lofting in a three dimensional domain from one position to another of the vane blocker.
The swirling flow path is the encircling cavity formed in the splash vane in between the adjacent flow boundary walls 42, which accommodates the flow of fluid entering the vane opening at the top of the splash vane to its exit. The swirling flow path 43, guides the fluid flow from the entrance at the top of the splash vane to exit at its bottom. The inner walls of the vane chamber of the nozzle form the outer enclosing boundary of the splash vane to contain the fluid flow in its swirling flow path. In the splash vane shown in
These two properties of the splash vane namely the thickness of the flow boundary wall 44, and the distance between the two flow boundary walls, the swirling flow path width 45, are defined by the rotation angle and the traversing distance of the vane blocker around and along the axis 51, which can be varied and scaled to make them non uniform. The height of the splash vane 46 and 47, and the turning of the flow from entrance position at the top of the splash vane to its bottom are determined by the rotation angle and traverse of the vane blocker. The longer the traverse, the taller the splash vane height. Higher the rotation angle, the larger the entrance and exit angles 48 and 49 of the fluid. The splash vane can be made to turn the fluid in the nozzle as many turns as one wants. By the same token they also can be made as long or short as one needs. The height of the splash vane (including retaining ring, if present) relative to the nozzle internal height (defined as the total height of the vane chamber 23, swirling chamber 24, and flow contraction area 28) may be varied to control the shape of the fluid jet exiting the nozzle. In embodiments, a ratio of splash vane height to nozzle internal height is between about 0.2 and 0.7. In one embodiment, a ratio of splash vane height to nozzle internal height of less than 0.5 provides a fluid jet having the shape of a full cone. In another embodiment, a ratio of splash vane height to nozzle internal height between about 0.5 and 0.75 provides a fluid jet having the shape of a hollow cone.
The splash vane of the
Further it may be instructive to note that splash vanes with a plurality of openings can be devised to suit ones purpose.
These splash vanes can be designed to effect a plurality of flow properties. These geometrical variations can be scaled to make these configurations shorter, longer with as much of swirl or rotations as one desires. In embodiments, the flow paths complete between 0.5 to 3 revolutions about the central longitudinal axis. While these geometrical variations of the splash vane have a significant effect on the flow properties of the exit jets from the nozzle, the exit angle of the flow from such changes has considerable effect on the impact force of the exit jets for shower applications. By managing the rotation angle and traversing distance of the blocker one can make the fluid entrance angle much lower; to contain the entrance losses; and at the same time the exit angle can be made very large to reduce the impact force of the droplets from the exit jet.
These unique splash vanes were installed in the splash nozzles used in the shower head. The splash vanes when inserted into the splash nozzle fit snugly into their vane chamber. Such unique splash vane-splash nozzle embodiment incorporated into the splash spray shower head made it a unique shower device.
It should be noted here that the swirling flow paths in the splash vane configurations shown in this investigation are laid out in a clockwise direction. As such the flow in the vane swirl chamber rotates in clockwise direction. They can just as well be laid out in anticlockwise direction making the flow rotate in anticlockwise direction in the swirl chamber of the splash nozzle with no change in their performance.
In summary, it is the combination of the plurality of splash nozzles comprising a vorticity generating element and an atomizing element with or without a retaining ring that makes these splash spray shower heads provide a shower of fluid droplets of desired diameter with low heat loss over a large area of the body to wash off efficiently in a warm comfortable environment with as little an amount of water as is possible.
These embodiments of a splash vane, a vorticity generating element and an atomizing element, are unique and different in purpose and performance and are one of a kind with its unique capability of generating a class of jets comprising full cone jets to hollow cone jets with a measured change of the splash vane inlet opening geometry.
While the preceding narration describes our invention in significant detail, it is by no means an exhaustive examples of the possible embodiments encompassing the full range of applications and variations of this invention. The informed and skilled in the art will realize that many other forms, variations and applications of the splash vane depicted in
A demonstrated example of significant variation of the flow properties of the jets exiting from the splash nozzles is presented in
Another example of importance is to investigate the effect of splash vane configuration with a plurality of vane openings 50 as shown in
One could also choose a design, for example, to vary the number of rotations of the swirling fluid flow in the vane chamber of the splash nozzle by varying the geometrical design of the swirling flow paths 43 and the flow boundary walls 42 of the splash vane to alter the properties of the exiting fluid jets from the splash nozzles within the inventive scope of this invention.
This application claims the filing benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/584,247, filed 10 Nov. 2017, which is hereby incorporated by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 916984 | Bleymehl | Apr 1909 | A |
| 1310938 | Ballerstedt | Jul 1919 | A |
| 2458876 | Rehn | Jan 1949 | A |
| 2752201 | Blass | Jun 1956 | A |
| 3104829 | Wahlin | Sep 1963 | A |
| 5232165 | Tournier | Aug 1993 | A |
| Number | Date | Country | |
|---|---|---|---|
| 62584247 | Nov 2017 | US |
