1. Field of the Invention
The subject invention relates to spray nozzles for use in spray drying applications, and more particularly to, spray nozzles of the type which employ locating and/or wear part retention/locking features to facilitate ease of replacement and handling of internal nozzle components and the reinstallation of the assembled unit in the nozzle location.
2. Background of the Related Art
Fluid nozzles or atomizers having a spiral swirl chamber and a spray orifice disposed within a nozzle body have been employed in the past for various applications, including spray drying, aeration, cooling, and fuel injection. U.S. Pat. No. 3,680,793 to Tate, which is herein incorporated by reference in its entirety, discloses a spray nozzle that includes a swirl chamber configured such that the origin of the spiral flow in the swirl chamber and the spray orifice formed in the orifice disc are eccentrically offset relative to each other. The spray orifice and the spiral flow origin were eccentrically offset from each other so as to improve the spray patternation in both large and small spray nozzle applications.
Spray drying is the transformation of a feed liquid from a fluid state into dried particulate form by spraying atomized feed into a gaseous drying medium. The liquid feed can be either a solution, suspension, dispersion, emulsion or slip. Often, the liquid feed contains abrasive solids. The atomization of the feed is accomplished by a spray nozzle. The nozzle must disperse the liquid into small droplets, which should be well distributed into the air stream and also serve as the metering device for the feed system.
In applications such as spray drying, the energy for atomization is supplied solely by the liquid feed pressure with inlet pressures typically exceeding 5,000 psi and occasionally reaching 10,000 psi. Due to the high inlet pressure, the liquid feed passes through the flow passages of the spray nozzle at a high velocity. Liquid feed containing abrasive solids and traveling at a high flow velocity causes erosion of the flow passages in the swirl chamber and orifice disc. As a result, the swirl chamber and orifice disc need to be replaced somewhat routinely.
In most nozzles, replacement of the internal components first requires the removal of the nozzle assembly from the fluid delivery system. Then an adapter which is normally threadably secured to the nozzle body must be disengaged. The adapter functions to secure the internal components, namely the swirl chamber, orifice disc and O-ring seals (adapter and orifice), within the nozzle body. The adapter also facilitates the axial alignment of the swirl chamber by providing a recess for the swirl chamber in its down stream end. Next an adapter seal, which is disposed between the adapter and the swirl chamber is removed. At this point, the remainder of the internal components can be freely removed.
Reassembling the spray nozzle is accomplished by reversing the disassembly procedure. However, difficulty is often encountered when attempting to engage the nozzle body, including the orifice disc and associated O-ring, with the adapter. Generally, the adapter is placed on a flat surface and the orifice disc is placed on top within the alignment recess. The nozzle body with orifice disc disposed therein is also placed on a flat surface with the discharge orifice facing down. In order to assemble the nozzle, either the adapter or the nozzle body have to be inverted. However, when inverting either the nozzle body or the adapter to engage the parts, the internal components unseat, become misaligned and often fall out.
There is a need therefore, for a spray nozzle which facilitates replacement of worn internal components by proving a mechanism for aligning and securing the internal components prior to engagement of the adapter with the nozzle body.
The subject application is directed to a new and improved spray nozzle which includes a nozzle body, a swirl element and an orifice disc. The nozzle body has opposed upstream and downstream end portions. The upstream end portion includes a fluid receiving section and the downstream end portion includes a fluid discharge section and defines a spray opening for emitting an atomized spray therefrom. The nozzle body defines a central bore which extends between the fluid receiving section and the fluid discharge section and delineates a central axis and delimits an interior locating surface for the nozzle.
The swirl element is disposed within the central bore of the nozzle body and is positioned adjacent to the fluid receiving section. The swirl element has a peripheral surface and defines an interior swirl cavity. Preferably, the peripheral surface has an upstream and a downstream portion, the downstream portion being configured for slidable engagement with the locating surface of the nozzle body. The upstream portion has a fluid inlet formed therein to provide a path for fluid to communicate between the fluid receiving section of the nozzle body and the interior swirl cavity of the swirl element.
The interior swirl cavity of the swirl element is defined by an approximately curvilinear surface for imparting a spiral flow to the fluid passing therethrough and includes a fluid outlet for discharging the spiral flow therefrom. Additionally, in a preferred embodiment, the swirl element further includes a recessed surface formed in the upstream portion of the peripheral surface for facilitating fluid flow between the upstream portion of the peripheral surface and the nozzle body. In one embodiment, the recessed surface formed in the peripheral surface of the swirl element has a trapezoidal axial cross-section.
In an alternate embodiment, the swirl element further includes a tapered neck portion associated with an upstream end thereof. The tapered neck portion, by providing a smooth transition, facilitates the communication of fluid between the fluid receiving portion of the nozzle body and fluid inlet of the swirl element. The tapered neck portion also prevents material blockages from forming within the internal flow path and reduces the pressure loss across the nozzle assembly.
The orifice disc is also disposed within the central bore of the nozzle body and is positioned upstream of the fluid discharge section. The orifice disc includes axially opposed upstream and downstream surfaces which define a peripheral surface therebetween. The peripheral surface is configured for slidable engagement with the interior locating surface of the nozzle body.
A spray orifice extends between the opposed upstream and downstream surfaces and is in fluid communication with the fluid outlet of the swirl cavity and the discharge section of the nozzle body. It is presently envisioned that the orifice disc has a protuberance associated with the downstream surface thereof which projects into the spray opening of the nozzle body and prevents the incorrect orientation of the disc. In a preferred embodiment, the protuberance has a chamfered downstream edge which facilitates the insertion of the protuberance into the spray opening of the nozzle body.
It is envisioned that the spray nozzle further includes an adapter member which is engaged with the upstream end portion of the nozzle body so as to contain the orifice disc and swirl element within the bore of the nozzle body. Preferably, the upstream end portion of the nozzle body has male threads associated therewith for engagement with corresponding female threads associated with the adapter member.
Preferably the central bore of the nozzle body further includes a second interior locating surface having two radially opposed recesses formed therein. The second interior surface is positioned radially outward of the interior locating surface so as to facilitate the communication of fluid between the upstream portion of the swirl element peripheral surface and the nozzle body.
In a preferred embodiment, the spray nozzle of the present disclosure further includes a locking plate disposed within the central bore of the nozzle body and positioned upstream of the swirl element. The locking plate is rotatably engaged within radially opposed recesses formed in the central bore of the nozzle body. It is envisioned that the recesses are formed in a plane which passes through the central axis of the nozzle at a right angle. In an alternate embodiment, the recesses are angled with respect to a plane passing through and perpendicular to the central axis. As a result, the rotational engagement of the locking plate with the recesses increases a contact pressure applied by the locking plate to the swirl element. It is presently preferred that the locking plate also includes a tool engaging portion which facilitates the rotational engagement of the locking plate within the recesses.
Alternatively, the spray nozzle disclosed herein can include a retainer element in lieu of the locking plate. The retainer element is also disposed within the central bore of the nozzle body and positioned upstream of the swirl element. The retainer element includes a retainer disc and a seal member. The retainer disc has opposed upstream and downstream planar surfaces and a peripheral surface extending therebetween. A groove formed in the peripheral surface and the seal member is disposed within the groove. The seal member engages with a corresponding recess formed in the central bore of the nozzle body so as to secure the retainer element, swirl element, and orifice disc within the central bore of the nozzle body. In a preferred embodiment, the retainer disc includes flow apertures formed therein which extend between the opposed upstream and downstream planar surfaces. The flow apertures providing for fluid communication between the fluid receiving portion of the nozzle body and the upstream portion of the swirl element peripheral surface.
The present disclosure is also directed to an orifice disc for a spray nozzle which includes a nozzle body. The nozzle body has opposed upstream and downstream end portions. The upstream end portion includes a fluid receiving section and the downstream end portion includes a fluid discharge section and defines a spray opening for emitting an atomized spray therefrom. The nozzle body defines a central bore which extends between the fluid receiving section and the fluid discharge section and delineates a central axis and delimits an interior locating surface for the orifice disc.
The orifice disc includes axially opposed upstream and downstream surfaces which define a peripheral surface therebetween. The peripheral surface is adapted and configured for slidable engagement with the interior locating surface of the nozzle body. The orifice disc further includes a spray orifice that extends between the opposed upstream and downstream surfaces. The downstream surface has a protuberance formed thereon for increasing the axial length of the spray orifice. It is envisioned that the spray orifice of the orifice disc further includes a tapered inlet formed in the upstream surface of the orifice disc so as to centrally direct fluid provided thereto. Preferably, the protuberance has a chamfered downstream edge which facilitates the insertion of the protuberance into the opening of the nozzle body.
The present disclosure is also directed to a spray nozzle which includes a nozzle body, a swirl element, an orifice disc and a locking mechanism. The nozzle body, swirl element and orifice disc being similar to those described for previous embodiment. The locking mechanism is disposed within the central bore of the nozzle body and is positioned upstream of the swirl element. The locking mechanism is dimensioned and configured for engagement with at least one groove formed in the central bore of the nozzle body. In one embodiment, the locking mechanism is provided in the form of a plate member. Alternatively, the locking mechanism includes protrusions formed on the upstream portion of the swirl element peripheral surface which are adapted and configured for engagement with the at least one groove. Also, the locking mechanism can be formed as an independent structural element or can be integral with the swirl element.
In an alternative embodiment, the locking mechanism includes a retainer element disposed within the central bore of the nozzle body which is positioned upstream of the swirl element. The retainer element includes a retainer disc and a seal member. The retainer disc has opposed upstream and downstream planar surfaces and a peripheral surface extending therebetween. A recess is formed in the peripheral surface and the seal member is disposed therein. When the retainer element is disposed within the central bore, the seal member engages with the at least one groove formed in the central bore. It is envisioned that the retainer disc includes flow apertures which extend between the opposed upstream and downstream planar surfaces to provide fluid communicated between the fluid receiving portion of the nozzle body and the upstream portion of the swirl element peripheral surface.
Preferably, the locking mechanism includes a tool engaging portion for facilitating the rotational engagement of the locking mechanism with the recesses formed in the central bore, where such rotational movement is required to remove the locking mechanism.
Those skilled in the art will readily appreciate that the subject invention facilitates the replacement of worn internal nozzle components and the reassembling of the nozzle, whilst ensuring the retention of said internal components during the reinstallation process of the assembled nozzle. These and other unique features of the spray nozzle disclosed herein will become more readily apparent from the following description, the accompanying drawings and the appended claims.
So that those having ordinary skill in the art to which the subject invention appertains will more readily understand how to make and use the same, reference may be had to the drawings wherein:
a is a cross-sectional view of a spray nozzle constructed in accordance with an alternate embodiment of the subject invention, wherein an orifice disc and swirl element are secured within the nozzle body by a retaining element which includes a retaining disc and seal member;
b is a partially exploded view of the nozzle body of
a is a cross-sectional view of the retainer disc which illustrates a groove formed in the periphery of the disc for receiving a seal member;
b is a partially exploded view of the groove formed in the retainer disc of
c is a top plan view of the retainer disc of
These and other features of the subject invention will become more readily apparent to those having ordinary skill in the art from the following detailed description of preferred embodiments.
In the description which follows, as is common in the art to which the subject invention appertains, “upstream side” shall refer to the end of the component which faces the inlet side of the nozzle, while “downstream side” shall refer to the side that faces the discharge orifice of the nozzle. In
Referring now to the drawings wherein like reference numerals identify similar elements of the subject invention, there is illustrated in
The nozzle body 10 is constructed from stainless steel and includes an opening 20 at the downstream end for the emission of spray from the orifice disc 12 and an elongated passage 22 for receiving the various components of the nozzle. A suitable gasket 24 is preferably disposed between shoulder 25 adjacent to opening 20 and the orifice disc 12. The gasket 24 prevents fluid from leaking around the periphery of orifice disc 12 and between the disc 12 and shoulder 25.
The swirl chamber member 14 has a spiral swirl chamber 16 formed therein with a generally tangential inlet 17. The swirl chamber member 14 is positioned adjacent to the orifice disc 12 such that the downstream side of the swirl chamber 16 communicates with a spray orifice 13 formed in the orifice disc 12, and the upstream side communicates with retainer member 18. Retainer member 18 is preferably cruciform in shape and is engaged with the nozzle body 10 by way of threads 26 to maintain the gasket 24, orifice plate 12, and swirl chamber block member 14 position, as shown in
As discussed previously, the flow passages in swirl chamber block member 14 and orifice disc 16 wear due to the flow velocity of the fluid and therefore, must be frequently replaced. However, due to the configuration of spray nozzle 100, reassembling the nozzle is difficult. In order to engage the nozzle body 10, including the orifice disc 12 and the associated O-ring 24, with the adapter 18, either the adapter 18 or the nozzle body 10 must be inverted. The inversion of the adapter 18 or the nozzle body 10 causes the internal components to unseat, become misaligned and often fall out.
Referring now to
The orifice disc 212 is disposed within the central bore 222 of the nozzle body 210 and is positioned adjacent to the discharge portion 220. An O-ring gasket 211 is provided between the orifice disc 212 and discharge portion 220 of the nozzle body 210. The gasket 211 provides a seal which prevents fluid from leaking around the periphery of the orifice disc 212 and between the orifice disc 212 and discharge portion 220 into spray opening 223.
As shown in
With continued reference to
In the assembled configuration, the adapter member 218 is threadably engaged with the second end 227 of the nozzle body 210 so as to contain the orifice disc 212 and swirl unit 214 within the bore 222 of the nozzle body 210. An adapter O-ring gasket 268 is disposed between the adapter member 218 and the nozzle body 210 for preventing fluid leakage from the assembled nozzle 200.
Liquid feed flows through nozzle 200 as indicated by the flow arrows. A feed supply conduit (not shown) is engaged with adapter 218 at surface 241. The feed passes through the adapter 218 and enters flow port 264 defined by the space between swirl unit 214 and nozzle body 210. As shown in
The liquid feed enters the swirl chamber 254 of the swirl unit 214 through fluid receiving portion 262 and a spiral motion is imparted thereon as known to those skilled in the art. The feed then exits the swirl chamber 254 through discharge portion 266 and is atomized by spray orifice 213. Atomized feed exits spray orifice 213 and spray opening 223 of the nozzle body 210.
With continuing reference to
After the gasket 211, orifice disc 212 and swirl unit 214 are positioned within the bore 222, locking plate 230 is installed through access segment cuts 270a and 270b provided in the nozzle body using a suitable fixing tool. When face 271 of locking plate 230 contacts the recesses 231a and 231b of the nozzle body 210, locking plate 230 is rotated clockwise into the recesses until the fully locked position is reached. The assembly, which includes the nozzle body 210, swirl unit 214, orifice O-ring gasket 211 and orifice disc 212 is thereupon a fixed unit and is ready for engagement with the adapter.
The locking plate 230 also includes a tool receiving portion 282 for facilitating the rotational engagement of the locking plate 230 with the nozzle body 210. The locking plate, in addition to securing the internal components within the nozzle body, provides a mechanism for ensuring that O-ring gasket 211 is properly compressed and a fluid tight seal is established between the orifice disc 212 and the discharge portion 220 of the nozzle body 210. This is achieved by selectively positioning the recesses 231a and 231b with respect to the second end 227 of the nozzle body 210 such that the desired compression is obtained. It should be noted that recesses 231a and 231b are formed such that they are positioned in a plane extending through central axis 240 at a right angle. Alternatively, the recesses could be formed in a plane which intersects the central axis 240 at an acute angle, and therefore, the rotational manipulation of locking plate 230 increases or decreases the compression of O-ring gasket 211.
Referring now to
Retainer element 330 is disposed within the central bore 322 of nozzle body 310 and is positioned upstream of swirl element 314. The retainer element 330 includes a retainer disc 332 and a seal member 342. As shown in
Retainer element 330 functions similar to that of locking plate 230 in that it facilitates the reassembling of nozzle 300. Retainer element 330 provides a mechanism for positively securing the orifice disc 312 and swirl unit 314 in place and compressing the orifice O-ring gasket 311 prior to threadably engaging the nozzle body 310 with the adapter 318. After the O-ring gasket 311, orifice disc 312 and swirl element 314 are positioned with the central bore 322, the retainer element 330 is inserted into the central bore 322 until the seal member 342 engages with recess 360. Recess 360 is positioned such that proper compression is applied to O-ring gasket 311.
With continued reference to
In contrast to swirl element 214 of
Those skilled in the art will readily appreciate that various materials can be used for the construction of the spray nozzle components disclosed herein. Spray nozzle wear largely depends upon its corrosion and erosion resistance. Corrosion occurs when the liquid feed and nozzle component material are chemically incompatible. Erosion results from the liquid feed with its abrasive solids passing through the flow passages at high velocities and physically removing component material. Corrosion problems can often be avoided or at least greatly reduced by determining the chemical characteristics of the liquid feed. Various materials can then be used based upon their ability to resists chemical and physical attack. Material possibilities are too numerous to list, but the materials disclosed herein are intended for illustrative purposes only and are not intended to limit the scope of the disclosure.
While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention with departing from the spirit or scope of the invention as defined by the appended claims.
Number | Name | Date | Kind |
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1183393 | Merrell | May 1916 | A |
2378348 | Wilmes et al. | Jun 1945 | A |
2921747 | Burman | Jan 1960 | A |
3304013 | O'Brien | Feb 1967 | A |
3441223 | Lapera | Apr 1969 | A |
3680793 | Tate et al. | Aug 1972 | A |
4079762 | Hanson, Jr. | Mar 1978 | A |
4103830 | Roth | Aug 1978 | A |
4258885 | Legeza | Mar 1981 | A |
4307840 | Schulze et al. | Dec 1981 | A |
4618101 | Piggott | Oct 1986 | A |
4736893 | Norskov | Apr 1988 | A |
5934569 | Soule et al. | Aug 1999 | A |
6193172 | Soule et al. | Feb 2001 | B1 |
Number | Date | Country |
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0 430 858 | Jun 1991 | EP |
336112 | Feb 2001 | NZ |
WO 9911382 | Mar 1999 | WO |
Number | Date | Country | |
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20070235564 A1 | Oct 2007 | US |