The present disclosure is related to spray nozzles and, more particularly, to spray nozzles for steam conditioning devices such as desuperheaters and steam conditioning valves.
Steam conditioning devices (e.g., desuperheaters and steam conditioning valves) are used in many industrial fluid and gas lines to reduce the temperature of superheated process fluid and gas to a desired set point temperature. For example, desuperheaters are used in power process industries to cool superheated steam. The desuperheater utilizes nozzles to inject a fine spray of atomized cooling water or other fluid, which can be referred to as a spraywater cloud, into the steam pipe through which the process steam flows. Evaporation of the water droplets in the spraywater cloud reduces the temperature of the process steam. The resulting temperature drop can be controlled by adjusting the characteristics of the spraywater cloud by adjusting one or more control variables, such as the flow rate, pressure and/or temperature of the cooling water being forced through the nozzles. But the adjustability of these control variables can be limited based on the mechanics of the nozzles themselves. For example, a nozzle equipped for high flow rate and/or high pressure conditions may not properly function at low flow rate and/or low pressure conditions. Thus, the operating range for any given set of nozzles must be considered when designing a steam conditioning device for any given application.
One aspect of the present disclosure provides a spray nozzle including a nozzle body, an outer valve stem, an inner valve stem, an outer bias device, and an inner bias device. The nozzle body has a proximal end, a distal end, a first through bore extending between the proximal and distal ends of the nozzle body, and an outer valve seat disposed at the distal end of the nozzle body. The outer valve stem is slidably disposed relative to the first through bore of the nozzle body and includes a proximal end, a distal end, and an outer valve head. The outer valve head carries an inner valve seat at the distal end of the outer valve stem, and a second through bore extends through at least a distal portion of the outer valve stem. The outer valve head is adapted to engage the outer valve seat of the nozzle body when the outer valve stem is in a closed position and adapted to be spaced away from the outer valve seat of the nozzle body when the outer valve stem is in an open position. The an inner valve stem is slidably disposed relative to the second through bore of the outer valve stem and includes a proximal end, a distal end, and an inner valve head disposed at the distal end of the inner valve stem. The inner valve head is adapted to engage the inner valve seat when the inner valve stem is in a closed position and adapted to be spaced away from the inner valve seat when the inner valve stem is in an open position. The outer bias device generates a first force biasing the outer valve head of the outer valve stem toward the outer valve seat of the nozzle body. The inner bias device generates a second force biasing the inner valve head of the inner valve stem toward the inner valve seat of the outer valve stem. So configured, the inner valve stem occupies the open position and the outer valve stem occupies the closed position upon the application of a first pressure on the distal ends of the inner and outer valve stems, and the inner and outer valve stems occupy the open positions upon the application of a second pressure that is greater than the first pressure on the distal ends of the inner and outer valve stems.
Another aspect of the present disclosure provides a steam conditioning device including a steam pipe, and a plurality of spray nozzles connected to a manifold and mounted about the steam pipe. The plurality of spray nozzles being adapted to deliver cooling water flow into the steam pipe, wherein each spray nozzle includes a spray nozzle as described above and throughout the present specification.
In some aspects, the first force generated by the outer bias device is greater than the second force generated by the inner bias device.
In some aspects, the nozzle body comprises a cylindrical wall defining the first through bore.
In some aspects, the outer bias device is disposed at the proximal end of the outer valve stem and the inner bias device is disposed at the proximal end of the inner valve stem.
In some aspects, the outer bias device comprises a first nut attached to the proximal end of the outer valve stem and a first spring biasing against the first nut, and the inner bias device comprises a second nut attached to the proximal end of the inner valve stem and a second spring biased against the second nut.
In some aspects, the first spring is disposed around the proximal end of the outer valve stem and the second spring is disposed around the proximal end of the inner valve stem.
In some aspects, the proximal end of the nozzle body defines a shoulder surface, and when the outer valve stem is in the closed position the first nut is spaced away from the shoulder surface, and when the outer valve stem is in the open position the first nut is in contact with the shoulder surface.
In some aspects, when the inner valve stem is in the closed position the second nut is spaced away from the first nut, and when the inner valve stem is in the open position the second nut is in contact with the first nut.
In some aspects, the nozzle body, the outer valve stem, and the inner valve stem are coaxially aligned.
In some aspects, the inner and outer valve stems move in a common first direction from the closed positions to the open positions.
In some aspects, the spray nozzle further includes a nozzle casing attached to the nozzle body and enclosing the proximal end of at least one of (a) the inner valve stem and inner bias device, and (b) the outer valve stem and outer bias device.
In some aspects, the spray nozzle further includes a nozzle coupler having a proximal end, a distal end and a third through bore extending between the proximal and distal ends of the nozzle coupler, the nozzle coupler fixed in the second through bore of the outer valve steam, the third through bore slidably receiving the inner valve stem and defining the inner valve seat at the distal end of the nozzle coupler.
In some aspects, the second nut is coupled to the proximal end of the nozzle coupler and the second spring is disposed between the second nut and the nozzle coupler.
The present disclosure is directed to a spray nozzle typically for use in steam conditioning applications such as desuperheaters and steam conditioning valves, for example, but other applications are contemplated. In the disclosed embodiments, the spray nozzle includes two or more operating stages for accommodating an increased range of cooling fluid operating pressures and flow rates through the nozzle. The two or more stages are achieved through the implementation of two or more valve stems sensitive to different operating pressures.
During operation, superheated steam or gas may flow along the flow path P in the steam pipe 10 at high temperatures ranging, for example, from approximately 1000° F. to approximately 1200° F. Depending on the temperature, composition and flow rate of the working fluid, the amount of cooling fluid needed to reduce the temperature to the set point may vary. As such, the amount and pressure of cooling fluid passing through the spray nozzles 100 can vary for different applications and environments. For example, in certain circumstances, it may be necessary to have high pressure and high flow rates of cooling fluid passing through the spray nozzles 100, while in other circumstances low pressure and low flow rates are needed. The present disclosure advantageously provides a single spray nozzle that can work in both situations, serving a large range of operating conditions, while also providing a compact device with optimum useful life. Typical steam pressures range from very low pressures down to as low as approximately 5 psia (vacuum) up to perhaps 2500 psia or more. Cooling fluid pressures then are typically in the range of 50-500 psi greater than the steam pressure. Steam and water flow rates can vary even more widely depending on pipe size and pressure, as well as how much temperature reduction is desirable in the particular desuperheating application.
The nozzle body 102 is a hollow generally cylindrical body including a proximal end 114, a distal end 116, a through bore 118, and an outer valve seat 120. The through bore 118 extends between the proximal and distal ends 114, 116 and includes an enlarged flow cavity 117 at the distal end 116. The outer valve seat 120 is disposed at the distal end 116 and includes an inner annular surface of the nozzle body 102 surrounding the enlarged flow cavity 117. In one version, the outer valve seat 120 includes a frustoconical surface extending at an angle α relative to a longitudinal axis A of the spray nozzle 100. The nozzle body 102 further includes a threaded region 122 disposed between the proximal and distal ends 114, 116 and threadably attached to the nozzle casing 112. So configured, the nozzle body 102 is fixed against axial displacement relative to the nozzle casing 112. The proximal end 114 of the nozzle body 102 is disposed inside the nozzle casing 112 and outside of the steam pipe 10. The distal end 116 of the nozzle body 102 is disposed outside of the nozzle casing 112 and inside of the steam pipe 10. In the disclosed embodiment, the threaded region 122 has a diameter that is large than a diameter of the proximal end 114 of the nozzle boy 102 and smaller than a diameter of the distal end 116 of the nozzle body 102. While the present version of the spray nozzle 100 has been described as including the nozzle casing 112, in other versions, the nozzle casing 112 may be considered a component of the spraywater manifold 18 or cylindrical wall 112 of the steam pipe 10. For example, in some embodiments, the nozzle casing 112 may be an integral part of the steam pipe 10 such that the nozzle body is threaded directly into the steam pipe 10.
Still referring to
The inner valve stem 106 is slidably disposed relative to the through bore 134 of the outer valve stem 104 and includes an elongated member disposed along the longitudinal axis A. In this version, the inner valve stem 106 is slidably disposed in the through bore 134. The inner valve stem 106 is coaxially aligned with the nozzle body 102 and the outer valve stem 104. More specifically, the inner valve stem 106 includes a proximal end 136, a distal end 138, and an inner valve head 140 disposed at the distal end 138. The inner valve head 140 includes an enlarged portion of the inner valve stem 106 that defines a seating surface 142 that can be a frustoconical surface disposed at the angle β relative to the longitudinal axis A of the spray nozzle 100. The seating surface 142 is therefore adapted to engage the inner valve seat 130 of the outer valve stem 104 when the inner valve stem 106 is in a closed position (e.g., as shown in
As mentioned above, the spray nozzle 100 of the present disclosure further includes outer and inner bias devices 108, 110. In the disclosed embodiment, the outer and inner bias devices 108, 110 respectively bias the outer and inner valve stems 104, 106 into their closed positions. That is, the outer bias device 108 generates a first force F1 biasing the seating surface 132 of the outer valve head 128 of the outer valve stem 104 toward the outer valve seat 120 of the nozzle body 102. Similarly, the inner bias device 110 generates a second force F2 biasing the seating surface 142 of the inner valve head 140 of the inner valve stem 106 toward the inner valve seat 130 of the outer valve stem 104.
In the disclosed version of the spray nozzle 100, the outer and inner bias devices 108, 110 are located at the proximal ends 124, 136 of the respective outer and inner valve stems 104, 106. And, as such, the outer and inner bias devices 108, 110 are located inside of the nozzle casing 112 of the version of the spray nozzle 100 depicted in
With more specific reference to
The first nut 144 is a hollow tubular member including a collar portion 154 and a shoulder portion 152 having threads 156 threadably coupled to the proximal end 124 of the outer valve stem 104. Additionally, the depicted version of the outer bias device 108 further includes a stop pin 157 extending through and coupling the first nut 144 to the proximal end 124 of the outer valve stem 104. The stop pin 157 can therefore prevent relative rotation of the first nut 144 and the outer valve stem 104, which can change the axial location of the first nut 144. The collar portion 154 defines an annular recess 155 in which the first spring 146 resides at a location compressed between the proximal end 114 of the nozzle body 102 and the shoulder portion 152 of the first nut 144. Thus, in the depicted version, the compressed first spring 146 exerts the first force F1 by bearing against the fixed nozzle body 102 to push the first nut 144 and therefore the outer valve stem 104 that is fixed to the first nut 144 away from the nozzle body 102.
The second nut 148 of the second bias device 110 is also a hollow tubular member including a collar portion 158 and a shoulder portion 160 having threads 162 threadably coupled to the proximal end 136 of the inner valve stem 106. Additionally, the depicted version of the inner bias device 110 further includes a stop pin 159 extending through and coupling the second nut 148 to the proximal end 136 of the inner valve stem 106. The stop pin 159 can therefore prevent relative rotation of the second nut 148 and the inner valve stem 106, which can change the axial location of the second nut 148. The collar portion 158 defines an annular recess 161 in which the second spring 150 resides at a location compressed between the proximal end 124 of the outer valve stem 104 and the shoulder portion 160 of the second nut 148. Thus, in the depicted version, the compressed second spring 150 exerts the second force F2 by bearing against the proximal end 124 of the outer valve stem 104 to push the second nut 148 and therefore the inner valve stem 106 that is fixed to the second nut 148 away from the outer valve stem 104 and the nozzle body 102.
In the disclosed embodiment, the first force F1 generated by the outer bias device 108 is greater than the second force F2 generated by the inner bias device 110. As such, the second spring 150 of the second bias device 110 can push the second nut 148 and inner valve stem 106 away from the outer valve stem 104 and nozzle body 102 without pushing the seating surface 132 of the outer valve stem 104 out of engagement with the outer valve seat 120 of the nozzle body 102. Moreover, this relationship of relative forces between the first and second springs 146, 150 facilitates the intended two-stage operation of the disclosed spray nozzle 100.
During operation, the spray nozzle 100 disclosed herein has one closed state and two operating states or stages.
During a first stage of operation, however, cooling fluid of a first pressure and flow rate can be supplied to the spray nozzle 100 by way of the nozzle casing 112 and, more particularly, applied to the distal ends 124, 136 of the outer and inner valve stems 104, 106. The cooling water is ultimately supplied to the enlarged flow cavity 117 in the nozzle body 102 by way of a flow conduit 166 in the nozzle body 102, and to the enlarged flow cavity 119 of the outer valve stem 104 by way of a flow conduit 168 in the outer valve stem 104. Thus, fluid pressure in the flow cavity 117 of the nozzle body 102 is applied to the exposed backside of the seating surface 132 of the outer valve stem 104, and pressure in the flow cavity 119 is applied to the exposed backside of the seating surface 142 of the inner valve stem 106. These applied pressures work against the biases of the first and second springs 146, 150.
In one embodiment, a first pressure is sufficient to overcome the second force F2 to move the inner valve stem 106 toward the nozzle body 102 such that the seating surface 142 moves to be spaced away from the inner valve seat 130 on the outer valve stem 104. In this position, as depicted in
As the pressure of the supplied cooling water is increased, it can also overcome the first force F1 such that the spray nozzle 100 operates in a second stage. In the second stage, a second fluid pressure greater than the first moves the outer valve stem 104 in the same direction as the inner valve stem 106 toward the nozzle body 102 such that the seating surface 132 moves to be spaced a second distance d2 (shown in
As with the nozzle 100 described above in
Still referring to
Continuing to refer to
The inner valve stem 206 of the version of the spray nozzle 200 depicted in
As shown in
As mentioned above, the spray nozzle 200 of the present disclosure further includes outer and inner bias devices 208, 210. In the disclosed embodiment, the outer and inner bias devices 208, 210 respectively bias the outer and inner valve stems 204, 206 into their closed positions. That is, the outer bias device 208 generates a first force F1 biasing the seating surface 232 of the outer valve head 228 of the outer valve stem 204 toward the outer valve seat 220 of the nozzle body 202. Similarly, the inner bias device 210 generates a second force F2 biasing the seating surface 242 of the inner valve stem 206 toward the inner valve seat 260 of the nozzle coupler 203.
In the version of the spray nozzle 200 in
In more detail, the disclosed version of the outer bias device 208 includes a first nut 244 and a first spring 246, while the inner bias device 210 includes a second nut 248 and a second spring 250. The first spring 246 can be disposed about or around the proximal end 224 of the outer valve stem 204 and the second spring 250 can be disposed about or around the proximal end 236 of the inner valve stem 206.
The first nut 244 is a hollow tubular member including a collar portion 268 and a shoulder portion 252 having threads 286 threadably coupled to the proximal end 224 of the outer valve stem 204. Additionally, the depicted version of the outer bias device 208 further includes a stop pin 267 extending through and coupling the first nut 244 to the proximal end 224 of the outer valve stem 204. The stop pin 267 can therefore prevent relative rotation of the first nut 244 and the outer valve stem 204, which can change the axial location of the first nut 244. The collar portion 268 defines an annular recess 255 in which the first spring 246 resides at a location compressed between the proximal end 214 of the nozzle body 202 and the shoulder portion 252 of the first nut 244. Thus, in the depicted version, the compressed first spring 246 exerts the first force F1 by bearing against the fixed nozzle body 202 to push the first nut 244 away from the nozzle body 202, thereby seating the seating surface 232 on the outer valve stem 204 against the valve seat 220 on the nozzle body 202.
The second nut 248 of the second bias device 210 is also a hollow tubular member including a collar portion 288 and a shoulder portion 270 having threads 272 threadably coupled to the proximal end 236 of the inner valve stem 206. Additionally, the depicted version of the inner bias device 210 further includes a stop pin 259 extending through and coupling the second nut 248 to the proximal end 236 of the inner valve stem 206. The stop pin 259 can therefore prevent relative rotation of the second nut 248 and the inner valve stem 206, which can change the axial location of the second nut 248. The collar portion 288 defines an annular recess 261 in which the second spring 250 resides at a location compressed between the proximal end 254 of the nozzle coupler 203 and the shoulder portion 270 of the second nut 248. Thus, in the depicted version, the compressed second spring 250 exerts the second force F2 by bearing against the proximal end 254 of the nozzle coupler 203 to push the second nut 248 away from the nozzle coupler 203, thereby seating the seating surface 242 of the inner valve stem 206 against the inner valve seat 260.
In the embodiment in
During operation, the spray nozzle 200 has one closed state or stage and two operating states or stages.
During a first stage of operation, however, cooling fluid of a first pressure and flow rate can be supplied to the spray nozzle 200 by way of the nozzle casing 212 and, more particularly, applied to the distal ends 224, 236 of the outer and inner valve stems 204, 206. The cooling water is supplied to the enlarged flow cavity 217 in the nozzle body 202 by way of at least a pair of flow conduits 278 extending axially through the nozzle body 202. Cooling water is further supplied to the enlarged flow cavity 257 in the nozzle coupler 203 via the conduit portions 237a, 237b and retention portion 235 of the through bore 234 of the outer valve stem 204. More specifically, as can be seen in
Thus, fluid pressure in the flow cavity 217 of the nozzle body 202 is applied to the exposed backside of the seating surface 232 of the outer valve stem 204, and pressure in the flow cavity 257 is applied to the exposed backside of the seating surface 242 of the inner valve stem 206. These applied pressures work against the biases of the first and second springs 246, 250.
In one embodiment, a first pressure is sufficient to overcome the second force F2 to move the inner valve stem 206 such that the seating surface 242 moves to be spaced away from the inner valve seat 260 on the nozzle coupler 203. In this position, a first cone of spray (not shown) is emitted from the spray nozzle 200 from a location between the inner valve stem 206 and the nozzle coupler 203. Before the fluid pressure overcomes the second force F2, the second nut 248 of the inner bias device 210 attached to the inner valve stem 206 is spaced away a distance from the proximal end 254 of the nozzle coupler 203, as shown in
As the pressure of the supplied cooling water is increased, it can also overcome the first force F1 such that the spray nozzle 200 operates in a second stage. In the second stage, a second fluid pressure greater than the first also moves the outer valve stem 204 in the same direction as the inner valve stem 206 such that the seating surface 232 on the outer valve head 228 moves to be spaced (not shown) away from the outer valve seat 220 on the nozzle body 202. In this configuration, the inner and outer valve stems 206, 204 occupy open positions. More particularly, the first nut 244 attached to the outer valve stem 204 moves from a position spaced away from a shoulder surface 274 on the proximal end 214 of the nozzle body 202 (shown in
Based on the foregoing, the present disclosure provides a spray nozzle that can operate in a first open stage at low pressures and high flow rates, and operate at a second stage at high pressures and high flow rates, which advantageously increase the total range of pressures and flow rates over known spray nozzles in similar applications. Moreover, the present disclosure provides a very simple and compact design with an optimal useful life. That is, because the various valve stem bias devices are located only in the cooling fluid flow path, they are not exposed to the superheated temperatures resident in the steam pipe which can degrade and weaken the bias device components. Furthermore, in some embodiments, the bias devices are of very simple construction, consisting only of nuts and springs attached to the proximal ends of the valve stems. This minimum number of components allows the overall axial and radial dimension of the spray nozzle to be minimized which facilitates handling, reduces material costs, and reduces the overall size of the steam pipe or other steam conditioning device to which the nozzles are attached.
While the foregoing description includes spray nozzles 100, 200 having two stage of operation—one with a single cone of spray and one with dual cones of spray—alternative forms of spray nozzles within the scope of the present disclosure may have three, four, or even more stages. In order to add stages, a person of ordinary skill would understand that additional valve stems could be nested inside of the inner valve stem 106, 206 of the disclosed spray nozzles 100, 200 but the same principles of operation would apply with each stage including a bias device generating slightly more force than the immediately prior bias device.
As mentioned above in relation to
Finally, based on the foregoing it should be appreciated that the scope of the present disclosure is not limited to the specific examples disclosed herein and a variety of changes and modifications can be useful depending on a desired end application and such changes and modifications are intended to be within the scope of the disclosure. Accordingly, the scope of the invention is not to be defined by the examples discussed herein and shown in the attached figures, but rather, the claims that are ultimately issued in a patent and all equivalents thereof.
Number | Name | Date | Kind |
---|---|---|---|
1876980 | Lentell, Jr. | Sep 1932 | A |
2063709 | Leonard | Dec 1936 | A |
2127188 | Schellin | Aug 1938 | A |
2313994 | Grant | Mar 1943 | A |
2320964 | Yates | Jun 1943 | A |
2801881 | Campbell | Aug 1957 | A |
3737105 | Arnold | Jun 1973 | A |
3850373 | Grolitsch | Nov 1974 | A |
4197997 | Wu | Apr 1980 | A |
4512520 | Schoonover | Apr 1985 | A |
4958771 | Klomp | Sep 1990 | A |
4991780 | Kannan | Feb 1991 | A |
5357914 | Huff | Oct 1994 | A |
5862992 | Stinson | Jan 1999 | A |
6729351 | Bircann | May 2004 | B2 |
6746001 | Sherikar | Jun 2004 | B1 |
7296545 | Ellingsen, Jr. | Nov 2007 | B2 |
7654509 | Freitas | Feb 2010 | B2 |
8327831 | Sturman | Dec 2012 | B2 |
8800895 | Hicks | Aug 2014 | B2 |
8955773 | Watson | Feb 2015 | B2 |
9631855 | Dodson | Apr 2017 | B2 |
20080308064 | Yudanov | Dec 2008 | A1 |
20120138710 | Hicks | Jun 2012 | A1 |
20140091485 | Watson | Apr 2014 | A1 |
20140252125 | Mastrovito | Sep 2014 | A1 |
20160033124 | Giove | Feb 2016 | A1 |
Number | Date | Country |
---|---|---|
2808957 | Sep 2013 | CA |
4213826 | Nov 1992 | DE |
102007054673 | May 2009 | DE |
0501164 | Sep 1992 | EP |
2415533 | Feb 2012 | EP |
WO-2013077849 | May 2013 | WO |
Entry |
---|
International Search Report and Written Opinion of the International Searching Authority for application No. PCT/US2017/047881, dated Nov. 2, 2017. |
Number | Date | Country | |
---|---|---|---|
20180058685 A1 | Mar 2018 | US |