Misting systems may be used to fulfill a plethora of functions, among which are: control of the environment of a greenhouse to aid in plant propagation; humidity control for fruit, vegetable, and wine storage; outdoor cooling for residential and commercial applications, including recreational use and animal husbandry; air filtration and dust abatement; and frost protection.
Such misting systems are distinct from sprinkling and/or spraying systems. Those skilled in the art will recognize that a misting system produces a mist, i.e., produces droplets small enough to be borne by the air. A cloud of water droplets is a mist if the droplets are less than 500 microns in diameter.
Droplets greater than 500 microns will precipitate, and therefore do not produce mist.
A misting system works by forcing water (or another fluid) through a specialized fluid-atomization (FA) nozzle (i.e., a misting nozzle) to produce a cloud of mist at a predetermined misting location. Those skilled in the art will appreciate that misting systems vary widely depending upon the characteristics of the system. For example, a misting system driven solely by the pressure of a municipal or other water supply at 60-50 psi (pounds per square inch) may produce a drizzle-like mist having droplets 100-250 microns in diameter.
Such a low-pressure system may be capable of reducing ambient temperature by 15.degree. F. in a given atmosphere. Conversely, a misting system driven by a pump at around 1000 psi may produce a fog-like mist having droplets approximately 5 microns in diameter. Such a high-pressure system may be capable of reducing ambient temperature by 35.degree. F. in the same atmosphere.
A misting system typically incorporates tubing or piping to convey the fluid (usually water) to the desired predetermined misting location. This tubing and associated apparatus (e.g., connectors, fittings, pumps, etc.) form a fluid-distribution (FD) subsystem of the misting system. The FD subsystem normally has a relatively large diameter (i.e., one-quarter to one-half inch standard tubing or piping) to permit relatively turbulent-free flow of the fluid at the required pressure. In normal practice, the diameter of the FD subsystem is a function of the size of the misting system. The greater the number of desired predetermined misting locations to which the fluid is to be distributed (i.e., the greater the fluid flow) and/or the distance between the fluid source and the farthest desired predetermined misting location, the larger the desired FD subsystem diameter. It will be recognized by those skilled in the art, however, that this is not an absolute rule. Other factors, such as tubing composition, fluid pressure, and environmental concerns, also have a bearing upon the diameter of the FD subsystem.
At the desired predetermined misting location, a misting system typically has a fitting with a nozzle coupled thereto. This fitting and nozzle, along with connectors, extensions, or other apparatus between the fitting and the nozzle, form a fluid-atomization (FA) subsystem of the misting system. The task of the FA subsystem is to render the fluid into a mist. This requires that the fluid be entrapped, fractured, and atomized. These are turbulent activities best isolated from the smooth flow of fluid in the FD subsystem. The FA subsystem, therefore, entraps the fluid in a connector or other apparatus having a very narrow diameter relative to the diameter of the FD subsystem. This isolates the turbulent activities of the FA subsystem from the smooth activities of the FD subsystem. Since the flow through an FA nozzle is very low, e.g., less than one and one-half gallon per hour in a typical high-pressure misting system, the small diameter of the FA subsystem has little effect on the resultant mist. A typical misting system has a plurality of such FA subsystems.
A problem arises, however, when it is desirous to produce a greater quantity of mist at a single predetermined misting location than is feasible with a conventional FA subsystem. Multiple interface fittings, hence multiple FA nozzles, may be placed in close proximity to provide increased misting capability. This multiple-fitting approach, however, generally produces less-than optimal results, and often produces unaesthetic layouts. In many cases, the requirements of the environment dictate the layout proximate the predetermined misting locations. In such cases, the multiple-fitting solution is contra-indicated.
A variation on the multiple-fitting approach is the branched-distribution approach. In the branched-distribution approach, short or specially shaped branches in the FD subsystem are implemented, with each branch having interface fittings and FA nozzles at the desired locations thereon proximate the preferred predetermined misting location. One example of this may be a cross (i.e., a double-tee) coupling two short secondary FD tubing to a primary FD tubing. Each secondary tubing may then have one or more interface fittings and FA nozzles. Similarly, a tee may couple a circular or serpentine secondary FD tubing having a plurality of interface fittings and FA nozzles.
Such multiple-FA subsystem approaches fail when retrofitting a pre-existing misting system or a misting system where the environment prohibits other than the primary FD tubing.