TWI553285B - Fan shroud for heat exchange tower fans - Google Patents

Description

Fan cover for heat exchange tower fan

The present invention relates to the field of heat exchange columns, and more particularly to the field of fans for moving air through a heat exchange column, including industrial cooling towers, industrial heating towers, and air-cooled steam condensers.

Various heat exchange tower systems are known in the industry. Such thermal communication towers include, for example, so-called industrial cooling towers for cooling warm water by industrial or other procedures. Such cooling towers typically have liquid sprayed from the inside of the top of the tower and fall onto a medium such as a splash rod or a kit that separates the film sheets. Air is typically drawn through the tower, transversely across the column, up through the column or a combination thereof, and interacts with the falling liquid. The drop system is warmer than the surrounding air and is thus cooled and dropped by this procedure into the collection tray at the bottom of the tower. Another type of heat exchange column can be used, for example, in a heating tower for the evaporation of liquefied natural gas.

Yet another type of tower is an air cooled condenser (ACC) tower. This tower is typically a large box-like structure with an open lower or side frame. The open frame can be closed on some of its sides. The frame supports a bottom plate having a series of fans that blow air up so that air is drawn through the open side of the tower and forced upward by the fan. The tower supports a series of condenser coils above the fan. In some examples, the plurality of steam supply manifolds run longitudinally on the top of the tower and distribute the steam downward into the condenser coils that extend downwardly. The water system is heated in a boiler to produce steam which is then passed to the high pressure end of a turbine to produce work (via energy changes in the steam). The steam at the low pressure end of the turbine is condensed by a condenser to create a vacuum that pulls the steam through the turbine. At the bottom of the downwardly inclined extended condenser coil is a series of collection tube header tubes that receive the condensate fluid and exit it. The entirety of the condenser coil is typically located on the fan. The air is discharged through the steam supply tube header tube to the open top of the tower. A bottom plate of a fan is added under the coil to provide a larger volume of air flow. A base plate typically has a plurality of fans spaced apart in a grid configuration, each surrounded by a fan shroud.

All of the above types of towers are suitable for a variety of applications and are widely accepted in the industry. However, it is often desirable to reduce the noise or sound generated by the tower in such tower installations. One of the main causes of noise or sound in some towers is the operation of the fan itself. In the case of ACC, a relatively large number of fans often occur, and thus the need to reduce the noise associated with each fan is sometimes even greater than with other types of heat exchange towers.

In one aspect, a heat exchange tower includes at least one fan having a fan blade having an outer tip that rotates in a circle of rotation; and a fan cover including an outer ring structure; and a sound absorption A material is disposed to the outer ring surface and radially disposed outside the outer ring structure and outside of the circle of rotation of the tips of the fan blades.

In another aspect, a heat exchange tower also includes at least one fan having a fan blade having an outer tip that rotates in a circle of rotation; and a fan cover having an outer support member; and a sound absorption A member is provided to the outer support member, the sound absorbing member being radially disposed outside the outer support member and outside the circle of rotation of the tips of the fan blades.

In still another aspect, a heat exchange tower has at least one fan having a fan blade having an outer tip that rotates in a circle of rotation; and a fan cover including an outer ring structure Formed by at least one molded section that forms at least one pocket and a sound absorbing material disposed radially outward of the inner circumference of the pocket and the circle of rotation of the tips of the fan blades.

Another aspect provides a method for reducing sound emitted by a heat exchange tower having at least one fan blade having an outer tip that rotates in a circle of rotation; and a fan cover surrounding the The tip of the rotating circle, the method comprising the step of providing a sound absorbing material on the inner surface of the inner surface of the cover and the inner surface of the cover between the rotating circles of the blade tips.

Yet another aspect provides an air-cooled condenser having a plurality of condenser coils, a fan floor disposed under the condenser coil, the fan floor comprising a plurality of fans having fan blades having a circle of rotation a rotating outer tip; and a plurality of fan covers each surrounding an additional fan, each fan cover including an outer ring structure; and a sound absorbing material disposed to the outer ring surface and radially disposed on the outer ring structure And the outer side of the circle of rotation of the tips of the fan blades.

The detailed description of the present invention has been set forth in the claims Additional embodiments of the invention will be described hereinafter and will form the subject matter of the appended claims.

In this regard, the detailed description of the embodiments of the invention, and the details of The present invention is capable of other embodiments, and may be embodied and carried out in various ways. In addition, it is to be understood that the phrase and terminology used herein is for the purpose of description and

Thus, those skilled in the art will understand that the conception of the present disclosure may be readily utilized as a basis for the design of other structures, methods and systems for carrying out the several objects of the invention. Therefore, it is important that the scope of the patent application be construed as including such equivalent constructions as long as they do not depart from the spirit and scope of the invention.

Some embodiments of the present invention provide a fan shroud for a heat exchange tower fan that includes a noise reducing material that reduces fan noise from the heat exchange tower. In some embodiments, the fan shroud includes an outer ring structure and the sound absorbing material is disposed outside the outer ring structure and outside of the circle of rotation of the fan blade tip. Some preferred embodiments of the invention will now be described with reference to the drawings, in which like reference numerals

Referring now to Figure 1, an air cooled condenser (ACC) column 10 is shown. The tower includes a base 12 that is placed on the ground and a frame 14 that supports a fan floor 16. The lower frame 14 is simply shown as a foot at the corner of the tower. However, those skilled in the art will appreciate that the frame 14 is typically an internal lattice frame having cylinders and enclosures interconnected to form an open frame. All four sides of the frame can be opened under the fan floor 16, or in some instances, each side of the opposite side can have a closed wall. Examples of ACCs described herein will be described in the context of having two end walls labeled 18 and 19 closed and two sides labeled 20 and 21 open. However, it should be understood that there may be any number of open or closed sides below the fan floor 16.

The fan floor 16 is a support structure that typically supports a plurality of fans (for clarity of the blade, not shown in Figure 1), each fan having its own fan cover 26 coupled thereto. Fan shroud 26 is discussed in further detail below. Fan 24 blows air up through a series of inclined condenser tube coil structures 28. The coil 28 is an elongated coil that generally forms air through a planar sheet-like structure. The coil 28 receives steam from a plurality of steam supply headers 30. The steam supply pipe header is introduced into the coil 28 and the steam/water falls vertically downward through the coil 28 and is cooled by heat exchange with the ambient air outside the coil 28. The steam condenses into water, which is collected in the lower water collecting pipe header 32 and discharged from the tower.

An upper frame structure 40 is typically provided to provide overall structural support for areas having supply headers 30, condenser coils 28, and water headers 32. The coil and the tube assembly are built into an upper superstructure. The frame structure 40 is used for a simple structure of the housing. The housing may extend to the bottom of the steam tube header or may extend some moderate distance above the steam tube header. This upper frame 40 will typically have a cladding 42 on all four sides or on all four sides that are closed by solid or substantially non-porous sidewalls. It will be appreciated that many of the solid project wall systems, such as the side walls, are shown to be transparent in Figure 1 to provide an internal view of the tower 10.

Figures 2 through 6 show a first preferred embodiment of the invention. In this embodiment the fan shroud 26 includes a constricted or flared, inwardly tapered inlet section 102, and a noise absorbing section 104 disposed at an axial position of the fan and when rotated Surround the fan tip.

The noise absorbing section 104 is adapted to reduce the sound from the particular fan tip and generally from the fan. The constricted or flared inlet section 102 can be a relatively well known construction and can be made, for example, from a segment of molded fiberglass material, or can be a steel sheet from a section or a continuous piece. The noise absorbing section 104 includes a sound absorbing material 114 as part of it. Various configurations for setting the sound absorbing material 114 are discussed further herein. The sound absorbing material may comprise any sound absorbing material known or to be discovered in the future, such as glass fiber batting or foam. Additionally, the sound absorbing material may comprise an irregularly shaped surface material. By way of example, only some suitable materials include acoustic foams, such as those made by SONEX®, or all flexible polyurethanes, polyimines, melamines, and other absorbents that are open and closed. Foam, or flexible outer viscoelastic and constrained layer products available from SOUNDCOAT®. For example, a simple glass fiber wadding for insulation is also suitable. In addition, in addition to the above and other passive materials, topical active materials can be used. A combination of different sound absorbing materials can be used. Further, the sound absorbing material may integrally span around the periphery of the noise absorbing portion 104, may span the arched portion of the noise absorbing portion 104, and may span a portion or the entire height of the noise absorbing portion 104. Moreover, although the noise absorbing portion 104 is referred to herein as having a straight side for convenience, it is of course also possible that either or both of its inner and outer surfaces have a slightly convex surface, or a slightly concave shape, or may have an undulating shape. Further, the noise absorbing portion 104 may simply be a truncated cone-shaped horn in the upward or downward direction, or a combination of one of the outward and upward horn cones.

In particular, turning to Figures 4 and 5, the noise absorbing section 104 is illustrated as having an outer ring 106 having a straight C-shaped cross section and having a straight side outer wall 108 and top and bottom walls 110 and The 112-roll steel cylinder is formed. This configuration is also characterized by the thickness of the sound absorbing material 114, which in a preferred embodiment may be a fiberglass wadding. As discussed herein, the sound absorbing material 114 can be other materials such as foam or have complex Miscellaneous reflection or material that attracts surface finishes. In addition, the sound absorbing material 114 can be made using a combination of various sound absorbing materials.

In the illustrated embodiment, an inner screen 120 is provided on the side of the location of the sound absorbing material 114. The screen 120 is at least slightly permeable to sound so that sound will be absorbed by the sound absorbing material 114, and further provides structural support to maintain the sound absorbing material 114 in position. In this particular embodiment, a steel screen having an open area of 20 to 50 percent is used. Examples of suitable screens include metal or plastic sheets that are pierced with holes or slots, or metal or plastic mesh. In the case of sound absorbing material 114 that loses its integrity when subjected to airflow, vibration, and/or moisture, screen 120 is used to maintain the function of sound absorbing material 114 in its positioning so that it does not tend to tear or broken. The screen 120 also reduces moisture which will enter the sound absorbing material 114 in the event that, for example, rain falls into the fan shroud. In the particular embodiment depicted in Figures 3 through 5, the integral fan shroud 26 (including the sound absorbing material features) is supported from above by a fan bottom plate 16 by using a conventional support arrangement.

Figure 6 shows the outer screen 106 of the composite screen 120 forming a hollow pocket 122. The sound absorbing material 114 is not shown in Fig. 6. Figure 6 also shows that the outer ring 106 can be formed from a number of roll box-shaped curved steel segments that can be engaged by the flanges 124 that receive the bolts into adjacent flanges of adjacent arcuate segments. Figure 6 also illustrates a flange 126 provided along the bottom of the ring 106 that facilitates engagement with the flared inlet portion 102.

Figures 7 and 8 illustrate a second embodiment utilizing the principles of the first embodiment described above, with some variations and additional features added. For example, in the particular embodiment of Figure 7, a flared inlet portion 202 is integral with the outer ring of the noise absorbing section 204. Thus, a unitary cover is formed by a plurality of arcuate sections, wherein each section has a flared inlet portion 202 and an outer ring on one of the sound absorbing portions 204. In the example of Figure 7, the integral cover is made from a plurality of arched sections. In this example, each arcuate section has been molded from a fiberglass material. Engagement flanges 224 are provided and can be threaded to each other. In the case of a fiberglass construction, the intermediate reinforcing steel sheets can be threaded to be sandwiched between adjacent flanges 224.

Turning further to the sound absorbing portion 204 in the specific embodiments of Figures 7 and 8, it will be appreciated that each segment forms part of the sound absorbing portion 204 and has one or more pockets 222 that are molded directly into the structure. In the examples of Figures 7 and 8, the two elongated pockets 222 are molded one on the other. This provides an intermediate rib structure 223 that enhances the rigidity of the section between the pockets 222.

As with the specific embodiment discussed above, a screen 220 provides a portion that forms the inner surface of the fan shroud. The sound absorbing material 214 is disposed between the screen 220 and the holes 222. As illustrated in Figure 7, the sound absorbing material 214 includes segments of fiberglass batts 208 disposed in front of the wavy glass fiber sheet. The glass fiber wadding 208 tends to absorb sound, while the wavy fiberglass sheet reflects sound in different directions to further reduce its propagation. Waveglass fiber sheet can also Used in the first embodiment described above. Moreover, it may be omitted from this particular embodiment, and while glass fiber floes are discussed with respect to the second embodiment, any other sound absorbing material or combination of materials may be utilized. In the specific embodiment of Figures 7 and 8, the screen can be screwed into the ring structure by screws 232.

The examples described above show that the sound emitted by the fan floor in the ACC can be reduced. The aspects of these specific embodiments can also be applied to other heat exchange tower fans.

The many features and advantages of the invention are set forth in the description of the invention. In addition, the present invention is not limited to the exact construction and operation shown and described, and thus may be modified and equivalent by the scope of the invention. Effective content.

10‧‧‧Air-Cooled Condenser (ACC) Tower

12‧‧‧ Pedestal

14‧‧‧ Lower frame

16‧‧‧Fan bottom plate

18‧‧‧End wall

19‧‧‧ End wall

20‧‧‧ side

21‧‧‧ side

24‧‧‧fan

26‧‧‧Fan cover

28‧‧‧ coil

30‧‧‧Steam supply pipe header

32‧‧‧Water collection tube header

40‧‧‧Upper frame structure

42‧‧‧Cover

102‧‧‧ Entrance section

104‧‧‧Noise absorption section

106‧‧‧Outer Ring

108‧‧‧ lateral outer wall

110‧‧‧ top wall

112‧‧‧ bottom wall

114‧‧‧Acoustic Absorbing Materials

120‧‧‧ screen

122‧‧‧ hollow hole

124‧‧‧Flange

126‧‧‧Flange

202‧‧‧ flared entrance section

204‧‧‧Noise absorption section

208‧‧‧glass fiber floc

214‧‧‧Acoustic Absorbing Materials

220‧‧‧ screen

222‧‧‧ points

223‧‧‧Intermediate ribbed structure

224‧‧‧Flange

232‧‧‧screw

Figure 1 is a schematic perspective view of an air-cooled condenser having a fan bottom plate with a plurality of fan shrouds.

Figure 2 is a top plan view of a fan surrounded by a fan shroud.

Figure 3 is a cross-sectional view of a fan and a fan cover taken through line 3-3 of Figure 2 in accordance with a first embodiment of the present invention.

Figure 4 is a detailed view of a fan cover taken through the enlarged circle of Figure 3.

Figure 5 is a partial cross-sectional view of a fan cover.

Figure 6 is a cut-away perspective view of the fan cover shown in Figure 5.

Figure 7 is a partially exploded view of a fan cover in accordance with a second preferred embodiment of the present invention.

Figure 8 is a cross-sectional detail view of the fan cover of Figure 7.

202. . . Flared inlet section

204. . . Noise absorption section

208. . . Glass fiber floc

214. . . Sound absorbing material

220. . . Screen

222. . . hole

223. . . Intermediate rib structure

224. . . Flange

Claims (23)

A heat exchange tower comprising: at least one fan having fan blades, the fan blades having an outer tip rotating in a circle of rotation; a tower outlet having a fan cover, the fan cover comprising: an outer ring structure, Wherein the outer ring structure comprises a plurality of individual arcuate segments interconnected to each other, wherein each arcuate segment comprises at least two elpngated pockets that are laterally separated by a ribbed structure And a sound absorbing material disposed on an inner side of each of the elongated holes and outside of the rotating circle of the tips of the fan blades. The heat exchange tower of claim 1, wherein the arcuate sections are connected to adjacent arcuate sections through the joint flange. The heat exchange column of claim 1, wherein each of the arcuate segments has a length, and the holes extend throughout the length, and the sound absorbing material extends throughout the length. The heat exchange column of claim 2, further comprising a rib structure, wherein the flanges and the rib structures must interrupt the sound absorbing material around the outer ring structure. The heat exchange tower of claim 1 wherein the fan shroud includes a flared inlet portion that is directed into the outer ring structure. The heat exchange column of claim 5, wherein the inlet portion is integral with the outer ring structure. The heat exchange column of claim 1, further comprising an inner structure sandwiching the sound absorbing material between the inner structure and the outer ring structure. The heat exchange column of claim 7, wherein the inner structure comprises a metal mesh. The heat exchange column of claim 1, wherein each of the arcuate segments is a molded glass fiber. The heat exchange column of claim 1, wherein the sound absorbing material is a glass fiber wadding. The heat exchange column of claim 1, wherein the sound absorbing material is a foam. A heat exchange tower comprising: At least one fan having fan blades having an outer tip that rotates in a circle of rotation; a tower outlet having a fan shroud, the fan shroud comprising: an outer support member that includes each other Connecting a plurality of individual arcuate segments, wherein each of the arcuate segments includes at least two elongated cavities that are laterally separated by a rib structure; and a sound absorbing member that sets the sound absorbing member The inside of each of the elongated cavities and the outside of the circle of rotation of the tips of the fan blades. The heat exchange tower of claim 12, wherein the arcuate segments are joined to adjacent arcuate segments by a joint flange. The heat exchange column of claim 12, wherein each of the arcuate segments has a length, and the holes extend throughout the length, and the sound absorbing member extends throughout the length. The heat exchange tower of claim 13, further comprising a rib structure, wherein the flanges and the rib structures must interrupt the sound absorbing member around the outer support member. A heat exchange tower according to claim 12, wherein the fan cover includes a flared inlet portion that is guided into the outer support member. The heat exchange column of claim 16, wherein the inlet portion is integral with the outer support member. The heat exchange tower of claim 12, further comprising an inner support member sandwiching the sound absorbing member between the inner support member and the outer support member. The heat exchange column of claim 18, wherein the inner support member comprises a metal mesh. A heat exchange column according to claim 12, wherein each of said arcuate segments is a molded glass fiber. The heat exchange column of claim 12, wherein the sound absorbing member is a glass fiber wadding. The heat exchange column of claim 12, wherein the sound absorbing member is a foam. An air-cooled condenser comprising: a plurality of condenser coils; a tower outlet having a fan cover, the fan cover comprising: an outer ring structure, wherein the outer ring structure comprises interconnecting each other a plurality of individual arcuate segments, wherein each of the arcuate segments includes at least two elongated cavities that are laterally separated by a rib structure; and a sound absorbing material disposed on the sound absorbing material An inner side of each of the elongated cavities and an outer side of the rotating circle of the tips of the fan blades; and an upper frame assembly extending over the cover, wherein the frame assembly encloses the plurality of condensers A coil and the outer ring structure, wherein the frame assembly is substantially non-porous.