200946859 六、發明說明： 【發明所屬之技術領域】 本發明係關於熱交換塔的領域，且尤其係更關於用以 f過熱交換塔移動空氣之風扇的領域，包括工業冷卻 塔、工業加熱塔及氣冷式蒸汽凝結器。 【先前技術】 ® I種熱交換塔係工業中為人已知。此等熱交流塔包括 (例如）所謂工業冷卻塔，其係用以藉由工業或其他程序 冷卻溫水。&等冷卻塔典型Λ有從塔頂部内㈣喷激之液 體，且落下在例如飛濺桿或分隔薄膜片之套件的一媒體 上。空氣典型係透過塔汲取，橫向跨過該塔，向上通過 該塔或其組合，且與落下液體相互作用。落下液體係比 周圍空氣溫暖’及因此係藉由此程序冷卻及落下進入至 在塔底部之收集盤。另一類型之熱交換塔係可用於（例如） ® 液化天然氣的蒸發之加熱塔。 又另一類之塔係氣冷式凝結器（ACC)塔。此一塔典型 地係一具有一開放下或側框架的大盒子狀結構。開放框 架可在一些其側面上為封閉。該框架支撐一底板，其具 有一系列將空氣向上吹之風扇以致空氣係透過塔之開放 側被汲取進入且藉由風扇強制向上。該塔在風扇之上支 撐一系列凝結器盤管。在一些實例中，複數蒸汽供應管 集箱管在塔頂部上縱向運行且向下分配蒸汽進入向下傾 3 200946859 :延伸之凝結器盤管。水係在一鍋爐中加熱以產生蒸 =，其係接著被傳送至一渦輪之高壓端以產生功（經由蒸 汽中之能量變化渦輪之低壓端處的蒸汽係藉由凝結器 凝結以產生真空，其透過渦輪拉動蒸汽。在向下傾斜延 伸凝結器盤管之底部處係—系列收集管集lgt，其接收 凝結流體及使其從該塔離開^凝結器歸之整體通常係 位於風扇上。空氣係通過蒸汽供應管集箱管排放出塔的 ❹ 開放頂部。-風扇之底板係在盤管下增加以提供更大體 積的空氣流。-底板典型具有㈣拇狀配置隔開之一些 風扇，其各藉由一風扇罩圍繞。 所有以上類型之塔係適用於各種應用且在工業中被廣 泛地接受。然而，通常在此類塔安裝中需求減少由塔產 生的噪音或聲音。在一些塔中的噪音或聲音之一主要原 因係由風雇本身之操作所產生。在Acc之情況下經常 會出現相對較大數目的風扇，&因此減少關聯各風扇噪 ❿ 音之需求有時甚至比具有其他類型熱交換塔更大。 【發明内容】 在一態樣中，一熱交換塔包含至少一風扇，其具有之 風扇葉片具有在一旋轉之圓中旋轉的外尖端；及一風扇 罩，該風扇罩包含一外環結構；及一聲音吸收材料，其 係没置至該外環表面且徑向佈置在該外環結構内側及該 等風扇葉片之尖端的旋轉之圓的外側。 200946859 在另態樣中，一熱交換塔亦包含至少一風扇，其具 有之風扇葉片具有在-旋轉之圓中旋轉的外尖端；及一 風扇罩其具有一外支撐構件；及一聲音吸收構件，其 係《X置至外支撐構件’該聲音吸收構件係徑向佈置在該 卜支撐構件之内側及該等風扇葉片之尖端的旋轉之圓的 外側。 在又另一態樣中，一熱交換塔具有至少一風扇其具200946859 VI. Description of the Invention: [Technical Field] The present invention relates to the field of heat exchange towers, and more particularly to the field of fans for moving air in a superheat exchange column, including industrial cooling towers, industrial heating towers and Air-cooled steam condenser. [Prior Art] ® I heat exchange towers are known in the industry. Such heat exchange towers include, for example, so-called industrial cooling towers for cooling warm water by industrial or other processes. Cooling towers such as & typically have a liquid that is sprayed from inside the top of the tower (4) and falls onto a medium such as a splash rod or a kit that separates the film sheets. Air is typically drawn through the column, 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 thus is cooled and dropped by this procedure into the collection tray at the bottom of the tower. Another type of heat exchange tower can be used, for example, for the heating tower of the 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 upward 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 instances, a plurality of steam supply manifolds run longitudinally on top of the tower and distribute steam downwardly into a downward tilt 3 200946859: extended condenser coil. The water system is heated in a boiler to produce steam=, which is then sent to the high pressure end of a turbine to produce work (via the energy in the steam, the steam at the low pressure end of the turbine is condensed by a condenser to create a vacuum, It pulls steam through the turbine. At the bottom of the downwardly inclined extension condenser coil, a series of collection tubes lgt that receive the condensate and leave it from the tower. The condenser is generally located on the fan. The 顶部 open top of the tower is discharged through the steam supply pipe header tube. The bottom plate of the fan is added under the coil to provide a larger volume of air flow. The bottom plate typically has a fan that is separated by a (4) thumb configuration. Each is 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 towers in such tower installations. One of the main reasons for noise or sound is caused by the operation of the windemployer itself. In the case of Acc, a relatively large number of fans often appear, & The demand for fan noise is sometimes even greater than with other types of heat exchange towers. [Invention] In one aspect, a heat exchange tower includes at least one fan having fan blades in a circle of rotation a rotating outer tip; and a fan cover, the fan cover including an outer ring structure; and a sound absorbing material that is not disposed on the outer ring surface and radially disposed inside the outer ring structure and the fan blades 200946859 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 a support member; and a sound absorbing member, which is "X placed to the outer support member". The sound absorbing member is radially disposed outside the support member and outside the circle of rotation of the tips of the fan blades. In another aspect, a heat exchange tower has at least one fan
有之風扇葉片具有在一旋轉之圓中旋轉的外尖端；及一 風扇罩’該風扇罩包含—外環結構，其係由至少一模製 區段形成，該區段形成至少一穴及一聲音吸收材料，其 係佈置在該/、内侧及該等風扇葉片之尖端的旋轉之圓的 徑向外側。 另一態樣提供一用於減少藉由一熱交換塔發射之聲音 的方法，料具有至少—風扇葉片，其具有在—旋轉之 圓中旋轉的外尖端；及-風扇罩，其圍繞該等尖端的旋 轉之圓’該方法包含提供—聲音吸收材料之步驟，其係 在該罩之-内表面及該等葉片尖端的旋轉之圓間的該罩 之該内表面上。 其具有複數凝結器 又另一態樣提供一氣冷式凝結器 盤管，一佈置於凝結器盤營下之厨# 邇官下之風扇底板，該風扇底板 包含複數風扇’其具有之風扇葉片具有在—旋轉之圓中 旋轉的外尖端，·及複數風扇罩，其各圍繞—個別風扇， 各風扇罩包含一外環結構；及一聲 耸9吸收材料，其係設 置至外環表面之且徑向佈置在外環址椹 丨辰、構内側及該等風扇 200946859 葉片之尖端的旋轉之圓的外側。 因此已相當廣泛地概述本發明之某些具體實施例以便 可更加理解本文中之其詳細描述，且以便對於此項技術 之目前貝獻可更加瞭解。當然下文中將描述本發明之附 加具體實施例且其將形成本文隨附申請專利範圍之標 . 的。 在此態樣中，在詳盡解釋本發明之至少一具體實施例 Φ 前，應理解不限制本發明之應用至以下描述中提出或圖 式中說明之構造細節及組件配置。本發明係能有該等經 描述以外之具髏實施例，且能依各種方式實現及實行。 另外，應理解本文以及摘要使用之詞組及術語係用於說 明之目的且不應視為限制。 因此，熟習此項技術人士應理解此揭示内容所依據之 概念可易於用作一用於實行本發明之若干目的之其他結 構、方法及系統的設計之基礎。因此，重要的是申請專 © 利範圍係視為包括此等等效構造’只要其不脫離本發明 之精神及範脅。 【實施方式】 本發明之-些具體實施例提供一用於熱交換塔風扇之 風扇罩’其包括-可減少來自熱交換塔之風扇噪音的噪 音減少材料。在-些具體實施例中，風扇罩包含一外環 結構且聲音吸收材料係佈置在外環結構内側及風扇葉片 200946859 尖端的旋轉之圓的外側。纟發明之一些較佳具體實施例 現將參考繪圖描述，其中全文中相似參考數字指相似部 分。 現參考第1圖，其顯示一氣冷式凝結器（八€(：;)塔丨〇。該 塔包括一置於地面上之基座12及支撐一風扇底板16之下 框架I4。下框架μ係簡單顯示為在塔角落處之支腳。然 而，熟習此項技術人士應瞭解此一框架14典型係一内部 ❹ 格狀框架’其具有彼此互連以形成開放框架之圓柱及包 圍。可使框架之所有四側在風扇底板16下開啟，或在一 些實例中相反側之兩側可各具卜封㈣。本文中㈣ 之ACC的實例將會在具有標示為⑽㈣封閉的兩端壁 及標示為20與21係開啟的兩側之背景下描述 '然而，應 理解在風扇底板16之下可具有任何數目之開啟或封閉 侧。 風扇底板16係一支撐結構，其典型支撑複數風扇（為Ί 說明清楚葉片未在第1圖中顯示），各風扇具有與其^ 之其自己的風扇罩26。風扇罩26係在下文中進—步詳知 討論。風扇24將空氣向上切過—系列傾斜凝結器管盘 管結構28。盤管28係細長盤管，其大體上形成空氣能經 過之一平面片狀結構。盤管28從複數蒸汽供應管集箱3( 接收蒸汽。蒸汽供應管集料人歸微蒸汽/水垂直地 向下落通過盤管28且係藉由與盤㈣外側之周圍空氣敎 200946859 交換而冷卻。蒸汽凝結成為水，其被收集在下方水收集 管集箱32内且從塔排放。 一上框架結構40係典型提供以對於具有供應管集箱 30、凝結器盤管28及水管集箱32之區域提供整體結構支 撐。盤管及管集箱件内建至一上方之上層結構内。框架 結構40係用於殼體之簡單結構。殼體可延伸至將近蒸汽 官集相的底部或可在蒸汽管集箱上方延伸某些適度距 離。此上框架40典型地將具有由實心或大體上非多孔側 壁封閉之所有四側或在所有四側上之包覆42。應瞭解在 第1圖中例如侧壁之許多實心項目壁係顯示為透明以致 能提供塔1 0之内部視圖。 第2至6圖顯示本發明之第一較佳具體實施例。在此具 體實施例中風扇罩26包括一收縮或喇叭狀、向内漸縮之 入口區段102，以及一噪音吸收區段1〇4，其係佈置在風 扇之轴向位置處，且當其旋轉時圍繞風扇尖端。 噪音吸收區段104係調適以減少來自尤其係風扇尖端 及一般來自風扇的聲音。收縮或喇叭狀入口區段1〇2可為 相對較I知構造及可為（例如）由模製玻璃纖維材料之 片段製成’或可為依區段或一連續件之輥製鋼。噪音吸 收區段104包括一聲音吸收材料114成為其一些部分。用 於設置聲音吸收材料114之各種配置係在本文中進_步 討論。聲音吸收材料可包含任何已知或將來會發現之聲 8 200946859 音吸收材料，例如玻璃纖維絮（batting)或泡沫。另外，聲 音吸收材料可包含不規則成型表面材料。藉由舉例言 之’僅有一些適合材料包括聲響泡沫，例如藉由s_X(g) 所製成，或開放及封閉之所有撓性聚氨基曱酸酯、聚醯 亞胺、三聚氰胺及其他吸收泡沫，或可從SOUNDC〇AT⑧購 得之撓性外黏彈性及限制層產品。例如用於絕緣之簡單 玻璃纖維絮亦適合。另外，除了以上及其他鈍性材料以 © 外，可使用局部活性材料。可使用不同聲音吸收材料之 組合。此外，聲音吸收材料可整體地橫跨圍繞噪音吸收 部分104之周圍’可橫跨噪音吸收部分ι〇4之拱形部分， 及可橫跨噪音吸收部分104之部分或整個高度此外，雖 然本文為了方便將噪音吸收部分i 〇4指為具有一筆直 側’其當然亦可使其内及外表面任一者或兩者具有稍微 凸面，或稍微凹面狀，或可具有起伏狀。此外，噪音吸 ® 收部分104可簡單地為一在向上或向下方向中之截頂錐 形喇11八狀，或向外及向上喇η八狀錐的之一組合。 現尤其係轉向第4及5圖，噪音吸收區段1〇4係說明為更 具有一外環106，其具有一筆直c形斷面及可藉由一具有 筆直側外壁108及頂部及扈部壁11〇及u2之輥製鋼圓柱 形成。該配置亦以聲音吸收材料114之厚度為特徵，其在 一較佳具體實施例中可為玻璃纖維絮。如本文中討論， 聲音吸收材料114可為例如泡沫之其他材料或具有複雜 9 200946859 反射或吸引表面加工的材料。另外’可使用各種聲音吸 收材料之組合來製成聲音吸收材料114。 在所說明的具體實施例_，一内篩網120係在聲音吸收 材料114之位置的側面提供。篩網12〇係對於聲音至少稍 微可滲透以致聲音將藉由聲音吸收材料n4吸收，及進一 步能提供結構支撐以保持聲音吸收材料114在定位❶在此 具體實施例中’係使用一具有百分之2〇至50開放區域之 ® 鋼筛網。適合篩網之實例包括用孔或槽打穿的金屬或塑 勝板’或金屬或塑膠網。在當經受氣流、振動及/或濕氣 而失去其完整性之聲音吸收材料114的情況下，篩網120 用於保持聲音吸收材料11 4於其定位之功能，以致其不會 傾向於撕裂或破碎。篩網120亦減少濕氣，其將在例如雨 落下進入風扇罩之情況下進入聲音吸收材料114»在第3 至5圖中描述的具體實施例中，整體風扇罩26(包括聲音 ® 吸收材料特徵）係藉著使用習知支撐配置由一風扇底板 16從上方支撐。 第6圖顯示組合篩網120形成一空心穴122的之外環 106。在第6圖中未顯示聲音吸收材料114。第6圖亦顯示 外環106能由一些輥製箱狀彎曲鋼片段製成，其能藉由容 納螺栓進入至相鄰拱形區段之相鄰凸緣的凸緣124接 合。第6圖亦說明一沿環106之底部提供的凸緣126，其可 促進與喇0八狀入口部分1 02之接合。 200946859 第7及8圖說明一利用以上所述第一具體實施例之原理 的第二具體實施例，但增加一些變動及附加特徵。例如， 在第7圖之具體實施例中，一喇σ八狀入口部分2〇2係與噪 音吸收區段204之外環成為整體。因此，一整體罩係藉由 複數梹形區段形成，其中各區段具有一下1八狀部分204 及一聲音吸收部分204之一上外環。在第7圖的實例中， 整體罩係藉由複數拱形區段製成。在此實例中，各拱形 區段已從玻璃纖維材料模製。接合凸緣224係提供，且可 彼此螺接。在玻璃纖維構造之情況下，中間強化鋼板可 螺接以夾在相鄰凸緣224之間。 進一步轉向在第7及8圖之具體實施例中的聲音吸收部 分204 ’應瞭解各區段形成聲音吸收部分2〇4之部分且具 有一或多數穴222,其係直接模製進入結構中。在第7及8 圖之實例中，兩細長穴222係模製成一者在另一者上。此 提供一在穴222間可增強區段之剛性的中間肋狀結構 223 〇 如具有以上时淪的具體實施例，一篩網22〇係提供形成 風扇罩之内表面的部分。佈置在篩網22〇.及穴222間係聲 音吸收材料214。如第7圖中說明，聲音吸收材料214包括 佈置在波形玻璃纖維片230前之玻璃纖維絮2〇8的片段。 玻璃纖維絮208傾向於吸收整立，品、a…j 汉^又笨曰’而波形玻璃纖維片230 在不同方向中反射聲音進一舟站+ # & 步減；其傳播。波形玻璃纖 200946859 維片230亦可用於以上描述的第一具體實施例中。此外， 其可自此具體實施例中省略，且雖然玻璃纖維絮係相對 於第一具體實施例討論，但可運用任何其他聲音吸收材 料或材料之一組合。在第7及8圖的具體實施例中，篩網 可藉由螺絲232螺入環結構2〇4中。 以上所述實例顯示可減少在ACC中藉由風扇底板發射 的聲音。亦可應用此等具體實施例之態樣至其他熱交換 ❹ 塔風扇。 本發明之許多特徵及優點可從詳細說明書中瞭解，且 因此預期藉由隨附申請專利範圍以涵蓋落入本發明之真 實精神及範疇的本發明之所有此等特徵及優點。此外， 因為對於熟習此項技術人士將易於產生各種修改及變 動，故無須將本發明限制至所說明及描述之確切構造及 操作，且因此可憑藉洛入本發明之範_的所有適合修改 ❹ 及等效内容。 【圖式簡單說明】 第1圖係一具有一風扇底板（其具有複數風扇罩）之氣 冷式凝結器之示意性透視圖。 第2圖係一藉由風扇罩圍繞之風扇的俯視圖。 第3圖係一依據本發明之第一具體實施例透過第2圖 中的線3-3取得的一風扇及一風扇罩之斷面圖。 12 200946859 第4圖係一透過第3圖的放大圓圈取得之一風扇罩的詳 圖。 第5圖係一風扇罩之部分剖視圖。 第ό圖係一在第5圖中所示之風扇罩的剖開透视圖。 第7圖係一依據本發明之第二較佳具體實施例的風 罩之部分分解圖。 第8圖係一第7圖之風扇罩的剖視詳圖。 【主要元件符號說明】 10 氣冷式凝結器（ACC)塔 12 基座 14 下框架 16 風扇底板 18 端壁 19 端壁 20 側面 21 側面 24 風扇 26 風扇罩 28 盤管 30 蒸汽供應管集箱 32 水收集管集箱 40 上框架結構 13 200946859 42 包覆 1 02入口區段 104噪音吸收區段 106外環 108側外壁 110頂部壁 112底部壁 114聲音吸收材料 ® 120篩網 122 空心穴 124凸緣 126凸緣 202喇η八狀入口部分 204噪音吸收區段 208玻璃纖維絮 H 214聲音吸收材料 220篩網 222 穴 223中間肋狀結構 224凸緣 230波形玻璃纖維片 232螺絲 14a fan blade having an outer tip that rotates in a circle of rotation; and a fan cover that includes an outer ring structure formed by at least one molded section that forms at least one hole and one A sound absorbing material disposed on a radially outer side of the circle of rotation of the /, inner side, and the tips of the fan blades. Another aspect provides a method for reducing sound emitted by a heat exchange tower having at least a 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 includes the step of providing a sound absorbing material on the inner surface of the cover between the inner surface of the cover and the circle of rotation of the blade tips. The utility model has a plurality of condensers and another aspect, which provides an air-cooled condenser coil, and a fan bottom plate disposed under the kitchen of the condenser, the fan bottom plate comprising a plurality of fans having fan blades having An outer tip that rotates in a circle of rotation, and a plurality of fan covers each surrounding each of the individual fans, each fan cover including an outer ring structure; and a sounding 9 absorbing material that is disposed to the outer ring surface and Radially disposed outside the outer ring, the inside of the structure, and the outer circle of the rotating tip of the blade of the fan 200946859. The detailed description of the present invention has been described by way of a It is a matter of course that the following detailed description of the invention is set forth in the accompanying claims. In this regard, the detailed description of the application and the configuration of the components as set forth in the following description or the drawings are not to be construed as limiting the invention. The present invention is capable of other embodiments than those described and can be implemented 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 this disclosure may be readily utilized as a basis for the design of other structures, methods and systems for carrying out several objects of the invention. Therefore, it is important that the scope of the application is to be construed as including such equivalent constructions as the invention may be [Embodiment] Some embodiments of the present invention provide a fan cover for a heat exchange tower fan' which 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 rotating circle of the tip of the fan blade 200946859. BEST MODE FOR CARRYING OUT THE INVENTION Reference will now be made to the drawings, in which like reference Referring now to Figure 1, there is shown an air-cooled condenser (eighth (:;) tower. The tower includes a base 12 placed on the ground and a frame I4 supporting a fan base plate 16. Lower frame μ The system 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 squash frame that has interconnects and are interconnected to form an open frame of cylinders and enclosures. All four sides of the frame are opened under the fan floor 16 or, in some instances, on either side of the opposite side, each of which may have a seal (4). An example of the ACC (4) herein will have both ends of the wall marked with (10) (four) and marked It is described in the context of the sides of the 20 and 21 series opening. 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 Ί It is clear that the blades are not shown in Figure 1. Each fan has its own fan cover 26. The fan cover 26 is discussed in more detail below. The fan 24 cuts the air upwards - a series of tilting condensers Tube coil Structure 28. Coil 28 is an elongated coil that generally forms air through a planar sheet-like structure. Coil 28 is supplied from a plurality of steam supply manifolds 3 (receiving steam. Steam supply pipe collectors are micro-steam/ The water falls vertically downward through the coil 28 and is cooled by exchange with the surrounding air 敎200946859 outside the disk (four). The steam condenses into water which is collected in the lower water collecting pipe header 32 and discharged from the tower. The frame structure 40 is typically provided to provide integral structural support for the area having the supply headers 30, the condenser coils 28, and the water headers 32. The coils and headers are built into an upper superstructure. The structure 40 is for a simple structure of the housing. The housing may extend to the bottom of the near-steam official phase or may extend some moderate distance above the steam tube header. This upper frame 40 will typically have a solid or substantially The cladding 42 of all four sides of the non-porous side wall closure or on all four sides. It will be appreciated that in Figure 1 a number of solid project wall systems such as side walls are shown to be transparent to provide an internal view of the tower 10. To 6 A first preferred embodiment of the present invention is shown. In this embodiment, the fan cover 26 includes a retracted or flared, inwardly tapered inlet section 102, and a noise absorbing section 1〇4, which is Arranged at the axial position of the fan and surrounding the fan tip as it rotates. 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 1〇2 For a relatively well-known construction and may be made of, for example, a segment of molded glass fiber material, or may be a section or a continuous piece of steel. The noise absorbing section 104 includes a sound absorbing material 114. Some of the various configurations for setting the sound absorbing material 114 are discussed herein. The sound absorbing material may comprise any known or future sound 8 200946859 sound absorbing material, such as 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 s_X(g), or all flexible polyaminophthalate, polyimide, melamine, and other absorbent foams that are open and closed. Or a flexible outer viscoelastic and constraining layer product available from SOUNDC(R) AT8. For example, a simple glass fiber wadding for insulation is also suitable. In addition, in addition to the above and other passive materials in addition to, a topical active material can be used. A combination of different sound absorbing materials can be used. Further, the sound absorbing material may integrally span the surrounding portion of the noise absorbing portion 104, which may span the arched portion of the noise absorbing portion ι 4, and may span a portion or the entire height of the noise absorbing portion 104, although It is convenient to refer to the noise absorbing portion i 〇 4 as having a straight side 'which of course may also have either or both of the inner and outer surfaces having a slightly convex surface, or a slightly concave shape, or may have an undulating shape. Further, the noise absorbing portion 104 can be simply a combination of one of the truncated cones 11 in the upward or downward direction, or one of the outward and upward η octagons. In particular, turning to Figures 4 and 5, the noise absorbing section 1 〇 4 is illustrated as having an outer ring 106 having a straight c-shaped cross section and having a straight side outer wall 108 and a top and ankle portion The roll steel cylinders of the walls 11〇 and u2 are 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 materials having a complex or intensive surface finish. Further, 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 position of the sound absorbing material 114. The screen 12 is at least slightly permeable to sound so that the sound will be absorbed by the sound absorbing material n4, and further provides structural support to maintain the sound absorbing material 114 in the position ❶ in this particular embodiment ® steel screens from 2〇 to 50 open areas. Examples of suitable screens include metal or plastic panels or metal or plastic mesh that are pierced with holes or slots. In the case of a sound absorbing material 114 that loses its integrity when subjected to airflow, vibration and/or moisture, the screen 120 serves to maintain the function of the 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 of, for example, rain falling into the fan shroud. In the particular embodiment depicted in Figures 3 through 5, the integral fan shroud 26 (including the sound absorbing material) The feature is supported from above by a fan bottom plate 16 by using a conventional support configuration. 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 joined by flanges 124 that accommodate the adjacent flanges of adjacent arcuate segments. Figure 6 also illustrates a flange 126 provided along the bottom of the ring 106 which facilitates engagement with the louvered inlet portion 102. 200946859 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 embodiment of Fig. 7, a sigma-shaped inlet portion 2〇2 is integral with the outer ring of the noise absorbing section 204. Thus, a unitary cover is formed by a plurality of dome-shaped sections, wherein each section has a lower one-eighth portion 204 and an outer outer ring of a sound absorbing portion 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. Further turning to the sound absorbing portion 204' in the specific embodiments of Figures 7 and 8 should be understood that each segment forms part of the sound absorbing portion 2〇4 and has one or more holes 222 which 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. For example, with a specific embodiment of the above, a screen 22 provides a portion that forms the inner surface of the fan shroud. Arranged between the screen 22 and the hole 222 is a sound absorbing material 214. As illustrated in Fig. 7, the sound absorbing material 214 includes a segment of the glass fiber wadding 2〇8 disposed in front of the wavy glass fiber sheet 230. The glass fiber floc 208 tends to absorb the erection, and the product, a...j is awkward and the wavy fiberglass sheet 230 reflects the sound in different directions into a boat station + # & step reduction; its propagation. Waveglass Fiber 200946859 The tile 230 can also be used in the first embodiment described above. Moreover, it may be omitted from this particular embodiment, and while the glass fiber floc is discussed with respect to the first 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 2〇4 by means of 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 apparent from 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 by the invention. And equivalent content. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic perspective view of an air-cooled condenser having a fan bottom plate having a plurality of fan covers. 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. 12 200946859 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. The figure is a cutaway perspective view of the fan cover shown in Fig. 5. Figure 7 is a partially exploded view of a hood according to a second preferred embodiment of the present invention. Figure 8 is a cross-sectional detail view of the fan cover of Figure 7. [Main component symbol description] 10 Air-cooled condenser (ACC) tower 12 Base 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 collecting tube header 40 Upper frame structure 13 200946859 42 Covering 102 Entrance section 104 Noise absorbing section 106 Outer ring 108 Side Outer wall 110 Top wall 112 Bottom wall 114 Sound absorbing material ® 120 Screen 122 Hollow hole 124 flange 126 flange 202 η n octagonal inlet portion 204 noise absorbing section 208 glass fiber wadding H 214 sound absorbing material 220 screen 222 hole 223 intermediate rib structure 224 flange 230 wave glass fiber sheet 232 screw 14