Abstract:
A pin jet nozzle for providing an evaporative fog in evaporative cooling systems or the like has a body member with an internal bore for receiving fluid under pressure, and an orifice receiving chamber integrally formed in the upper surface of the body member. The orifice receiving chamber is unitary with the body member and in fluid communication with the internal bore. An orifice member is directly secured in the orifice receiving chamber so that an orifice of the orifice member is coaxial with the internal bore. A pin member has an impingement pin with an impingement face that is spaced from, and in alignment with, the orifice.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to nozzles, and more particularly to pin-jet nozzles capable of producing fog in evaporative cooling systems and the like. 
     Evaporative cooling systems have been employed in various applications for a number of years. Such systems typically involve a pressurized fluid, usually water, escaping through a small orifice and impinging on a proximate surface. The force of the pressurized stream against the proximate surface causes the fluid to disperse into minute particles creating a localized fog. A fog differs from a mist, although the terms are often used imprecisely. As used herein, a fog contains small droplets which evaporate from the air rather than falling to cause a localized wetting. Fogs are typically used for cooling, and sometimes, for humidification. A mist, as used herein, contains larger particles which fall to create a localized wetting, and are typically used more for providing irrigation. 
     A pin-jet nozzle is typically used in a hydraulic system in which the water is pressurized to about 350 to over 1,000 pounds per square inch. At that pressure a thin, substantially-coherent stream of water is forced out through an orifice that is approximately six one-thousandths of an inch in diameter and against an external impingement pin, which is also about six one-thousandths of an inch in diameter, although it is common for larger size impingement pins to be employed. This creates droplets that are sufficiently small to be essentially unaffected by gravity because of their increased surface area in proportion to their volume. Water droplets of such small dimension evaporate in the air and therefore do not contribute to localized wetting and its consequent disadvantages, such as mildew, mold, and water damage. With the evaporation of each droplet, its heat of vaporization is removed from the ambient air, reducing the ambient air temperature. An array of 200 to 300 of these nozzles can cool a large area, including outdoor areas. 
     A suitable pin jet nozzle for producing fog is disclosed in U.S. Pat. No. 5,620,142 to Elkas, the disclosure of which is hereby incorporated by reference in its entirety. This patent teaches the use of an orifice member that is prepared from a ruby or sapphire wafer. An orifice is cut into the wafer and then wire polished to a tolerance (as small as 0.0002 inch) which is not possible with other techniques, such as drilling or extrusion. The wafer is then firmly held within a generally cylindrical insert member by standard metalworking techniques to expand a portion of the metal of the insert member over the surface of the orifice member. The insert member is then placed and secured into an orifice outlet of a nozzle body. Subsequently, an impingement pin is installed in alignment with the orifice. Although this fog nozzle was a vast improvement over the prior art, it has been found that the insert can deteriorate under acid cleaning. In addition, there is a possibility that leakage may occur between the mating surfaces of the insert member and the nozzle body. Accordingly, it is desirable to provide a fog nozzle that is less subject to deterioration and leakage than the prior art. 
     BRIEF SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a pin jet nozzle for providing an evaporative fog with fluid particles having a diameter of less than fifty micrometers comprises a body member, a disk-shaped orifice member directly secured to the body member, and a pin member mounted to the body member. The body member has upper and lower surfaces, an internal bore for receiving fluid under pressure, and an orifice receiving chamber integrally formed in the upper surface of the body member. The internal bore extends along an axis of the body member from the lower surface toward the upper surface. The orifice receiving chamber is unitary with the body member and in fluid communication with the internal bore. The orifice member is directly secured in the orifice receiving chamber so that an orifice of the orifice member is coaxial with the internal bore. The term “disk-shaped” as used herein means a member that is larger in cross dimension than in thickness, and thus does not necessarily refer to a cylindrical member. The pin member has an impingement pin with an impingement face that is spaced from, and in alignment with, the orifice. 
     According to a further aspect of the invention, pin jet nozzle for providing an evaporative fog comprises a body member, a disk-shaped orifice member directly secured to the body member, and a pin member mounted to the body member. The body member has upper and lower surfaces, an internal bore for receiving fluid under pressure, with the internal bore extending along an axis of the body member from the lower surface toward the upper surface and including lower, intermediate and upper bore portions, the upper bore portion being smaller in diameter than the intermediate bore portion which is in turn smaller in diameter than the lower bore portion, and an orifice receiving chamber that is integrally formed in the upper surface of the body member. The orifice receiving chamber is unitary with the body member and intersects with the upper bore portion so that the orifice receiving chamber is in fluid communication with the internal bore. The orifice receiving chamber comprises a first annular wall portion that surrounds the orifice member and extends in a first direction from the upper surface of the body member and a second annular wall portion that extends in a second direction toward the axis of the body member from the first wall portion. The orifice member is directly secured in the orifice receiving chamber of the body member and sandwiched between the upper surface and the second wall portion. The orifice member includes an orifice that is coaxial with the internal bore and smaller in diameter than the upper bore portion. The pin member includes an impingement pin with an impingement face that is spaced from, and in alignment with, the orifice. 
     According to an even further aspect of the invention, a method of forming a pin jet nozzle comprises the steps of: providing a body member with upper and lower surfaces; forming an internal bore in the body member, the internal bore extending along an axis of the body member from the lower surface toward the upper surface; forming an orifice receiving chamber in the upper surface of the body member, the orifice receiving chamber being unitary with the body member and in fluid communication with the internal bore; providing an orifice member with an orifice; securing the orifice member directly in the orifice receiving chamber of the body member so that the orifice is coaxial with the internal bore; and securing a pin member to the body member, the pin member including an impingement pin with an impingement face that is spaced from, and in alignment with, the orifice. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
     In the drawings: 
     FIG. 1 is a perspective view of a pin jet nozzle in accordance with the present invention; 
     FIG. 2 is a top plan view of the pin jet nozzle of FIG. 1; 
     FIG. 3 is a sectional view of the pin jet nozzle taken along line  3 — 3  of FIG. 1; 
     FIG. 4 is an enlarged sectional view of a nozzle body that forms part of the pin jet nozzle of FIG. 1; and 
     FIG. 5 is an enlarged sectional view of a portion of the pin jet nozzle. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings, and to FIG. 1 in particular, a pin jet nozzle  10  in accordance with the present invention is illustrated. The pin jet nozzle  10  includes a body member  12 , an orifice member  14  fixedly mounted in the body member  12 , and a pin member  16  mounted to the body member. 
     With additional reference to FIG. 2, the body member  12  is preferably constructed of nickel, silver, or stainless steel, but may be constructed of other suitable material or combination of materials. The body member  12  has a lower portion  20  with an external helical thread  22  and an upper portion  24  with flat faces  26  that can be engaged with a wrench or the like in a well-known manner for securing the pin jet nozzle  10  to a threaded opening of a pressurized hydraulic system (not shown). It will be understood that the pin jet nozzle  10  can be secured to the pressurized hydraulic system through other well-known securing means, such as welding, press-fitting, mutually engaging structure, and so on. 
     As shown in FIG. 3, an internal chamber or bore  30  is formed in the body member  12  and is preferably concentric with a central axis  32  of the body member. The bore  30  preferably has lower, intermediate and upper bore portions  33 ,  35  and  37 , respectively, that decrease in diameter in a step-wise fashion from the bottom surface  34  to the top surface  36  of the body member  12 . The bore  30  is arranged for receiving fluid from the pressurized hydraulic system and preferably includes a first inner transitional frustro-conical surface  38  that extends generally upwardly and inwardly from the bottom surface  34  to the lower bore portion  33 , a first inner circumferential surface  40  that defines the lower bore portion  33  and extends generally upwardly from the first transitional surface  38 , a second inner transitional frustro-conical surface  42  that extends generally upwardly and inwardly from the first circumferential surface  40  to the intermediate bore portion  35 , a second inner circumferential surface  44  that defines the intermediate bore portion  35  and extends generally upwardly from the second transitional surface  42 , a third inner transitional frustro-conical surface  46  that extends generally upwardly and inwardly from the second circumferential surface  44  to the upper bore portion  37 , and a third inner circumferential surface  48  that defines the upper bore portion  37  and extends upwardly to an orifice receiving chamber  50  from the third transitional surface  46 . Although a particular configuration of the internal bore  30  has been shown and described, it will be understood that other bore configurations with more or less bore portions of different diameters, cross-dimensions, and/or cross sectional shapes can be provided. 
     With particular reference to FIGS. 4 and 5, an annular wall  52  extends upwardly from the upper surface  36  to define the orifice receiving chamber  50 . The annular wall  52  includes a lower wall portion  54  that extends upwardly from the upper surface  36  and an upper wall portion  56  that initially extends upwardly from the lower wall portion  54 , as shown in FIG.  4 . Preferably, the upper wall portion is thinner than the lower wall portion so that it can be bent or otherwise deformed to extend inwardly toward the central axis  32  of the of the body member  12  and generally perpendicular to the lower wall portion  54 , as best shown in FIG.  5 . Prior to deformation of the upper wall portion  56 , the orifice member  14  is inserted into the orifice receiving chamber  50 . Once the upper wall portion  56  is deformed, the orifice member  54  is securely held within the orifice receiving chamber  50  and sandwiched between the upper wall portion  56  and the upper surface  36 . Standard metalworking techniques can be used to deform the upper wall portion over the surface of the orifice member  14 . The orifice member  14  should be held in a flat position, generally perpendicular to the central axis  32  of the body member  12 . Other techniques for firmly securing or holding the orifice member  14  on or in the body member  12  can be employed. 
     The orifice member  14  is preferably constructed of wear-resistant material that can be formed to precise tolerances, such as artificial jewel material, including ruby and/or sapphire, or other suitable material. The outer shape of the orifice member  14  is not critical, but the flat disk illustrated is preferred for ease in locating the orifice member  14  in the orifice receiving chamber  50 . An orifice  60  is formed in the orifice member  14 , preferably at a center of the disk and extends from a lower surface  62  to an upper surface  64  thereof. When the orifice member  14  is installed in the body member  12 , the orifice  60  is preferably in axial alignment with the central axis  32  and the upper bore portion  37  of the body member  12 . The orifice member is constructed of the wear-resistant material to precise tolerances, including at least one surface which is smooth and polished with no surface pocketing, scarring, voids, or imperfections. The orifice  60  is precision-cut with a laser and then polished by wire polishing to a tolerance which is not possible with machining or extrusion technologies. 
     With reference to FIGS. 3 and 5, the pin member  16  of the nozzle  10  has a support post  70  and an impingement pin  72  connected at a terminal end  74  of the support post, as in the prior art. The support post is generally inverted J-shaped and has a mounting end  76  that is securely affixed onto or into the body member  12 . The terminal end  74  of the support post is preferably aligned with the central axis  32  of the body member  12 , with an impingement face  74   73  of the impingement pin  72  centered over the orifice  60 . By virtue of the orifice size and tolerance, which define an exact output for each nozzle, the impingement pin  72  and the diameter of the impingement face  73  may be smaller in diameter than a comparable impingement pin of prior art pin jet nozzles. It has been common in the prior art to provide an impingement pin larger in diameter than the outlet orifice. As in the prior art, the impingement pin  73  is preferably axially positioned from the orifice  60  at a fixed distance. The exact dimension of the pin, its position and the geometry of its taper are believed to be within the knowledge of one skilled in the art. 
     The above-described arrangement of the present invention is capable of generating an evaporative fog with fluid particles that have a diameter of less than fifty micrometers. Further fluid input and output characteristics of the pin jet nozzle, as well as its use, are more fully disclosed in U.S. Pat. No. 5,620,142 to Elkas, the disclosure of which is hereby incorporated by reference in its entirety. Accordingly, the characteristics and use of the pin jet nozzle will not be further described. 
     By eliminating the prior art insert and mounting the orifice member  14  directly to the body member  12  in accordance with the present invention, deterioration of the insert under acid cleaning, as well as leakage between the insert and nozzle body are eliminated. 
     It will be understood that terms of orientation and/or position as used throughout the specification, such as top, bottom, upwardly, downwardly, inwardly, lower, intermediate, and upper, as well as their respective derivatives and equivalent terms, refer to relative rather than absolute orientations and/or positions. 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.