These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims, and accompanying drawings wherein:
The preferred embodiment of the present invention is illustrated by way of example below and in
In the discussion of the present invention, the invention will be discussed in a fire extinguishing environment; however, this invention can be utilized for any type of need that requires use of a fluids mixing nozzle. For instance, but without limitation, the fluids mixing nozzle may be used for: portable fire extinguisher nozzle or sprinkler head replacement; medical drug delivery or mixing and other medical applications; agricultural purposes; painting applications; fire suppression systems within aircraft cabins and storage bays; food processing applications; any application where an efficient mixture is required of two or more substances, liquids or gases; fuel nozzles; fuel furnaces; power plant scrubbers; and eductors (for mixing of powders).
The converging-diverging nozzle 17 includes a nozzle intake section 19, a convergent mixing flow zone 21 adjacent to the nozzle intake section 19, a throat section 23 adjacent to the convergent mixing flow zone 21, a divergent mixing flow zone 25 adjacent to the throat section 23, and a nozzle exit section 27 adjacent to the divergent mixing flow zone 25. In the preferred embodiment, the converging-diverging nozzle 17 has an inner diameter that has a cross section that is substantially circular. This inner diameter extends through the length of the converging-diverging nozzle 17. As shown in
In the preferred embodiment, the supply ports 11, 13 have a cross section that is substantially circular; however, they may have any type of cross section practicable. The first supply port 11 has a inner diameter of A, and the second supply port has a inner diameter of B.
Typically the diameter X of the nozzle intake section 19 is equal to the diameter Z of the nozzle exit section 27. However, in instances where several substances, liquids or gases are to be mixed through one fluids mixing nozzle 1, the diameter X of the nozzle intake section 19 and the nozzle port 15 is increased proportionately to the number of extra quantities of agents to accommodate the influx through the nozzle intake section 19 and into the convergent mixing flow zone 21. For maximum mixing and performance of the fluids mixing nozzle 1, the inside diameter Y of the throat section 23 is half that of the inside diameter Z of the nozzle exit section 27.
In preferred embodiments of the present invention, the following ratios of inner diameters of the first fluid supply port 11(A), the second fluid supply port 13(B), the nozzle intake section 19(X), the throat section 23(Y) and the nozzle exit section 27(Z), respectively, are as follows:
1. A=B=X=Z=2Y, for even preliminary fundamental mixing and even convergent mixing (preferred range, easiest to manufacture);
2. A=B=X=2Z=4Y or A=B=X=2Z=3Y, for even preliminary fundamental mixing and more convergent mixing;
3. A=B=2X=2Z=4Y, for enhanced preliminary fundamental mixing and even convergent mixing;
4. A=3B=3X=3Z=6Y or A=2B=2X=2Z=4Y, for uneven preliminary fundamental mixing and even convergent mixing;
5. A=3B=4X=5Z=6Y or A=2B=3X=4Z=5Y, for uneven preliminary fundamental mixing and uneven convergent mixing (most difficult to manufacture); and,
6. A=B=X=3Z=4Y or A=B=X=4Z=5Y, for even preliminary fundamental mixing and uneven convergent mixing.
In operation, fluids (or substances) enter the internal portion 7 of the mixing chamber 3 via the first supply port 11 and the second supply port 13. In another embodiment of the invention, there may be a plurality of supply ports in order to mix more than two fluids and/or substances. Fluids and/or substances of various types may enter the internal portion 7 of the mixing chamber 3 through the fluid supply ports, where they interact and mix. The supply ports may be in fluid communication with fluid holding tanks, which contain and/or store the respective fluids to be mixed. In a fire extinguishant environment, the fluid holding tanks may hold air and water, respectively. Another example of substances that can be used in the fluids mixing nozzle 1, but without limitation, is nitrogen (or an inert gas) with potassium powder or aerosol. Another example, particularly in a system with three fluid supply ports, could be water, a surfactant (to enhance water such as “FireBlock”) and an inert gas.
The preliminary mixture in the internal portion 7 of the mixing chamber 3 is mixed and reacts and then enters the converging-diverging nozzle 17 via the nozzle port 15. Upon entering the diverging-converging nozzle 17, the mixture enters the convergent mixing flow zone 21. The mixture is then choked and abruptly compressed as it flows through the throat section 23 and into the divergent mixing flow zone 25. The fully mixed resultant flow that exits through the nozzle exit section 27 is atomized into a fine mist, and can be used for desired result and intended applications.
If a gas is used as one of two constituents to be mixed the following process occurs: the gas and either a liquid or other substance (i.e. aerosol, powder, oil, kerosene, paint, medicine, pesticide, etc.) flow together into the internal portion 7 of the mixing chamber 3 and are preliminarily mixed. The gas and substance or liquid will encounter some additional preliminary mixing as they approach the throat section 23 of the converging-diverging nozzle 17. Then, the substance or liquid flows through the throat section 23 with the highly compressed gas. After passing through the throat section 23 of the diverging section of the converging-diverging nozzle 17 and into the divergent mixing flow zone 25, the gas rapidly expands with an increase in velocity. The energy from this rapid expansion of the gas shears the substance or liquid, causing it to shatter (explode) into droplets or particles. Effective atomization depends upon the viscosity of the substance or liquid to be mixed, and the ratio of gas to substance or liquid within the fluids mixing nozzle 1. This ratio can be varied by the operator or engineered into the system process to accommodate the desired result or intended application. This process usually occurs at low pressure (less than 50 psi), but higher pressures (greater than 50 psi) can be utilized if required for fine atomization of higher viscosity substances.
The fluids mixing nozzle 1 may also be utilized as a single stand-alone or part of a multiple nozzle array designed system. In an embodiment of the invention, there may be multiple diverging-converging nozzles 17.
Upon exiting the narrowed throat section 23, the flow rapidly expands into the divergent mixing flow zone 25, and then exits the converging-diverging nozzle 17 via the nozzle exit section 27. As discussed above, because of the compression and subsequent rapid expansion of the compressed flow (the mixed fluids/substances), the fluid(s) (and/or other substances) are sheared into small droplets or are atomized. The sequence discussed above is illustrated in
The fluids mixing nozzle 1 allows mixing of two or more gases, fluids or substances to achieve a multi-phase mixture therethrough, thereby effectuating efficient use of fully mixed agents. Further, the fluids mixing nozzle 1 herein works efficiently enough to allow a generally larger than conventional-sized nozzle for mixing of two or more gases, fluids or substances or combination thereof to be used, which tends not to clog like the conventional nozzles.
Other industries may require a hardened fluids mixing nozzle for abrasive substances or liquids and chemical solutions mixing.
Alternatives in construction of the fluids mixing nozzle 1 can be utilized. The fluids mixing nozzle 1 works well at very low pressures, therefore the use of plastics for a molded single unitary assembly is possible, as well as multiple elements of the same or different materials being connected so as to form the fluids mixing nozzle 1. Other alternatives in construction are possible depending on the mixing that may occur. For example, but without limitation, in some mixing applications a polished stainless steel may be the best construction, such as in the food or medical industries.
When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the,” and “said” are intended to mean there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Although the present invention has been described in considerable detail with reference to a certain preferred embodiment thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiment(s) contained herein.
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.