201236747 • 六、發明說明： 【智^月戶斤屬之„々貝】 技術領域 本發明係有關於一種使用於廢水等之處理之過濾膜元 件。 L· 3 背景技術 薄膜分離技術具有節能、節約空間、劣力及產品之品 質知·昇專特徵’故為應用範臂已擴大且普及之技術。薄膜 分離技術包含逆滲透、超濾、微濾、氣體分離、血液淨化 及滲透蒸發法等方法。且，過濾膜之形態包含平膜、中空 ' 纖維膜及管狀膜等，而對應上述各分離對象物之性質及特 • 徵加以區分使用。 迄今，微濾之範疇中，已就小型之盤濾機及平膜折疊 型濾心式過濾器使用目的在進行較少量之處理以及較清澈 之水溶液之分離、過據之技術。又’超濾之範嘴中，則已 就超純水之製造、食品製造及清涼飲料之製造等使用平膜 過濾裝置及中空纖維膜模組。 然而，近來則因環保之提倡，而發展了亦就廢水處理 應用薄膜分離技術之研究。 廢水處理大多包含藉沈澱而進行固液分離程序，故若 可實施薄膜分離技術予以取代，則不僅可獲致高品質之處 理水’並可省略或縮小大塑之沈澱池，極具空間上之優勢。 廢水處理已廣泛採用了藉稱為活性污泥之微生物分解廢水 3 201236747 中之有機物後，再分離已結塊之汙泥與處理水之活性污泥 處理程序。 活性污泥處理程序為提昇處理效率’―旦使活性污泥 提高濃度，則在進行分解處理時，可能發生後部之沈澱池 中汙泥之洗降性不佳之問題，而使用於避免水質惡化之管 理作業較為繁雜。 就上述汙泥與處理水之固液分離應用薄膜分離技術， 則即便進行高濃度活性污泥處理，亦不致發生水質惡化， 進而可省略沈澱池而極為節省空間。 依據以上各點，近年，如第6圖所示，已進行了浸入型 之過濾犋模組之研究，其係將使前述過濾膜與垂直方向大 致平行而積層複數片板狀之過濾膜元件1並予以固定而成 之過濾膜模組8，浸入活性污泥槽9内，再將自過濾膜元件1 製得之處理水集中於集水管13，並以幫浦1〇加以抽吸或如 虹吸管等般利用水位差而製得處理水者。活性污泥處理通 常須培養嗜氧性之微生物，故朝設於下方之散氣裝置11利 用送風機12而供給空氣以進行曝氣。上述浸入型可利用藉 曝氣而於活性污泥槽内形成之迴旋流6 ’而刮除過渡膜面之 汙垢同時進行固液分離，而可以極低成本進行運轉。 習知之過濾膜元件1構造一如第3圖所示，於端緣形成 有過濾水喷嘴4，並於形成有其所連通之過濾水流道槽（未 圖示）之板體2之兩面上配置有過濾膜3，板體之上端部5_ 般自根部至前端之厚度為固定，端緣則為略經倒圓角處理 之形狀。201236747 • VI. Description of the invention: [Ming ^ ^ 户 户 々 】 】 】 】 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 技术 。 。 。 。 。 。 。 。 。 。 。 。 Space, inferiority, and product quality know-up characteristics are the technology that has been expanded and popularized. The membrane separation technology includes reverse osmosis, ultrafiltration, microfiltration, gas separation, blood purification, and pervaporation. Further, the form of the filter film includes a flat film, a hollow fiber membrane, a tubular film, and the like, and is used in accordance with the nature and characteristics of each of the above-mentioned separation objects. So far, in the category of microfiltration, a small disk has been used. Filters and flat-film folded filter-type filters are used for the purpose of performing a smaller amount of processing and separation of clearer aqueous solutions. In the case of ultrafiltration, ultrapure water has been used. Flat membrane filtration devices and hollow fiber membrane modules are used in the manufacture of food, food manufacturing and refreshing beverages. However, recently, due to the promotion of environmental protection, the development of wastewater treatment should be Research on membrane separation technology. Most wastewater treatment involves solid-liquid separation process by precipitation. Therefore, if membrane separation technology can be replaced, it can not only obtain high-quality treatment water, but also omit or reduce the sedimentation tank of Daplastic. It has a space advantage. Wastewater treatment has been widely used to decompose activated sludge from activated sludge, which is an organic sludge in 201236747, and then separate the activated sludge from treated sludge and treated water. The mud treatment procedure is to improve the treatment efficiency. ——When the activated sludge is increased in concentration, the decomposition of the sludge in the sedimentation tank may be poor during the decomposition treatment, and the management operation for avoiding deterioration of the water quality may occur. The membrane separation technique is applied to the solid-liquid separation of the sludge and the treated water, so that even if the high-concentration activated sludge treatment is carried out, the water quality is not deteriorated, and the sedimentation tank can be omitted, thereby saving space. In recent years, as shown in Figure 6, the immersion type filter cartridge module has been studied, which will enable the aforementioned The filter membrane module 8 in which the filter membrane element 1 having a plurality of plate-like filter membrane elements 1 is laminated in parallel with the vertical direction, is immersed in the activated sludge tank 9, and the treated water obtained from the membrane element 1 is treated. Concentrated on the water collection pipe 13 and pumped with the pump 1 or using the water level difference as a siphon, etc. The activated sludge treatment usually has to cultivate the aerobic microorganisms, so it is placed below the scattered The air device 11 supplies air for aeration by the blower 12. The immersion type can use the swirling flow 6' formed by the aeration in the activated sludge tank to scrape off the dirt on the transition film surface while performing solid-liquid separation. The filter membrane element 1 of the prior art has a structure as shown in Fig. 3, in which a filtered water nozzle 4 is formed at the end edge, and a filtered water flow channel (not shown) is formed therein. The filter film 3 is disposed on both sides of the plate body 2, and the upper end portion of the plate body 5 is fixed in thickness from the root portion to the front end, and the end edge is slightly rounded.
S 4 201236747 上述過濾膜元件1並如第4圖所示，於迴旋流6通過板體 之上端部5時將發生卡門渦7，藉此而於過濾膜元件1之兩面 上產生交替之差壓。過濾膜元件1將朝壓力較低處受牽引， 但一般而言過濾膜元件1之左右兩邊已大致受固定，故過濾 膜元件1之水平方向之中央部則朝壓力較低處發生彎曲變 形。上述現象在兩面上交互發生，結果則使過濾膜元件1振 動，甚至受損，而成問題。 用於減少振動之方法在專利文獻i中提出了 一種方 法’乃經裝設於過濾膜元件之上下之端緣部之保持體而進 行積層’而得以對振動之力維持柔軟性。 然而’該方法需要作為保持體之追加構件，故有成本 將增加，且使組裝作業性降低之問題。 又’專利文獻2則揭露了一種於過濾膜元件之下端緣形 成朝外尖凸之錐部，而使空氣有效率地進入相隣之元件之 間之方法。 然而，該方法雖可提昇過濾膜面之汙垢之刮除效率， 仁無去抑制迴旋流通過板體之上端部時所發生之卡門渦所 致之振動，故尚不足以避免過濾膜元件之損傷發生。 又’專利文獻3則揭露了一種於較過濾膜之周緣端更偏 卜倒之慮板之表面上形成較對應過濾膜之周緣端之濾板之 表面更高之部分’而避免噴射清潔液以清洗薄膜濾心時發 生過據膜之剝離之薄膜濾心。 然而’該薄膜濾心乃設有凸部之構造，故雖具備避免 膜之制離之效果’但無法抑制迴旋流通過板體之上端部時 5 201236747 所發生之卡門渦所致之振動，而尚不足以避免過濾膜元件 之損傷。 先行技術文獻 專利文獻 專利文獻1:日本特開2004-121943號公報 專利文獻2:日本特開2008-73676號公報 專利文獻3 :國際公開第2〇〇9/〇69295號公報 C發明内容】 發明概要 發明欲解決之課題 本發明係提供一種在浸入型之過濾膜模組中，避免過 渡膜元件之板體之上端部之上方之卡門滿之發生，而藉減 少板體兩面之差壓以減少振動，且使活性污泥槽内之迴旋 流之流動順暢，而已提昇汙垢之刮除效率之過濾膜元件。 用以欲解決課題之手段 即，本發明係有關於以下之（1)〜(5)。 (1)一種過濾膜元件，包含有：板體；過濾膜，設於前 述板體之兩面上；過濾水噴嘴，形成於前述板體之端緣上； 及’過滤水流道槽’與前述過濾水喷嘴連通；其並配置成 使前述過濾膜與垂直方向大致平行而可供使用，其特徵在 於刖述板體之上鈿部包含愈接近前端厚度愈小之形狀之部 分0 ⑺如（1)之過軸it件，其特徵在於前述上端部包含錐 狀之部分。S 4 201236747 The above-mentioned filter membrane element 1 and as shown in Fig. 4, a Karman vortex 7 will occur when the swirling flow 6 passes through the upper end portion 5 of the plate body, thereby generating alternating differential pressure on both sides of the filtration membrane element 1. . The filtration membrane element 1 is pulled toward a lower pressure, but generally, the left and right sides of the filtration membrane element 1 are substantially fixed, so that the central portion of the filtration membrane element 1 in the horizontal direction is bent and deformed toward a lower pressure. The above phenomenon occurs alternately on both sides, and as a result, the filter membrane element 1 is vibrated or even damaged, which is a problem. The method for reducing the vibration is proposed in Patent Document i. The method is carried out by laminating the retaining body attached to the upper edge portion of the filter membrane element to maintain the flexibility against the vibration force. However, this method requires an additional member as a holder, so that the cost is increased and the assembly workability is lowered. Further, Patent Document 2 discloses a method of forming an outwardly convex tapered portion at the lower edge of the filter membrane member to allow air to efficiently enter between adjacent members. However, although this method can improve the scraping efficiency of the dirt on the surface of the filter membrane, it does not inhibit the vibration caused by the Karman vortex which occurs when the swirling flow passes through the upper end portion of the plate body, so it is insufficient to avoid damage of the filter membrane element. occur. Further, Patent Document 3 discloses a portion which is formed on the surface of the filter plate which is more inclined than the peripheral edge of the filter film to form a higher portion than the surface of the filter plate corresponding to the peripheral end of the filter film, and avoids spraying the cleaning liquid. When the film filter is cleaned, a film filter that peels off the film occurs. However, 'the membrane core is provided with a convex structure, so it has the effect of avoiding the separation of the membrane', but it cannot suppress the vibration caused by the Karman vortex which occurs when the swirling flow passes through the upper end of the plate. Not enough to avoid damage to the filter membrane element. CITATION LIST Patent Literature Patent Literature 1: Japanese Laid-Open Patent Publication No. JP-A No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. SUMMARY OF THE INVENTION Problem to be Solved by the Invention The present invention provides a filter module for immersing type which avoids the occurrence of a jammer above the upper end portion of the plate member of the transition film member, and reduces the differential pressure on both sides of the plate body to reduce A filter membrane element that vibrates and smoothes the flow of the swirling flow in the activated sludge tank, and has improved the scraping efficiency of the dirt. Means for Solving the Problem That is, the present invention relates to the following (1) to (5). (1) A filtration membrane element comprising: a plate body; a filtration membrane disposed on both sides of the plate body; a filtration water nozzle formed on an edge of the plate body; and a 'filter water channel groove' and the foregoing filtration The water nozzle is connected; and is disposed such that the filter film is substantially parallel to the vertical direction, and is characterized in that the upper portion of the plate body includes a portion closer to the front end than the thickness of the front end (0) as (1) The shaft member is characterized in that the upper end portion includes a tapered portion.
201236747 (3) 如（1)或(2)之過渡膜元件，其特徵在於前述上端部在 前述板體兩面上呈對稱形狀。 (4) 如（1)~(3)中任一之過濾膜元件，其特徵在於前述上 端部整體係愈接近前端厚度愈小之形狀。 (5) —種過渡膜模组，包含有：（1)〜(4)中任一之過渡膜 元件，配置複數個於框體内；及，散氣裝置，設於前述過 濾膜元件之下方。 另，本說明書中所謂「大致平行」乃包含鐘於本發明 之作用效果而視為平行之概念，即便並非真正平行亦無妨。 發明效果 將本發明之過濾膜元件設於過濾膜模組中並加以浸入 活性污泥槽内而加以使用，即可避免過濾膜元件之板體之 上端部之上方之卡門渦之發生，並藉減低板體兩面之差壓 而減少振動。 圖式簡單說明 第1圖係例示本發明之過濾膜元件者。 第2圖係係顯示本發明之過濾膜元件之上端部與迴旋 流者。 第3圖係例示習知之過濾膜元件者。 第4圖係顯示習知之過濾膜元件之上端部與迴旋流者。 第5(a)〜5⑴圖係顯示本發明之過濾膜元件之他例者。 第6圖係例示過濾膜模組者。 第7(a)〜7(c)圖係顯示實施例所使用之板體之上端部之 形狀者。 201236747 第8圖係顯示實施例之結果者。 I：實施方式3 用以實施發明之形態 本發明之過濾膜元件一如第1圖所示，於端緣形成過濾 水喷嘴4，並於形成有其所連通之過濾水流道槽（未圖示）之 板體2之兩面上配設有過濾膜3。 構成板體之材質雖無特別之限制，但就大量生產、成 本、輕量化之觀點而言，通常宜選擇適用於射出成形之樹 脂。進而，宜使用耐化學性優良者以避免受廢水中所含之 各種物質所侵蝕，一般係使用丙烯腈丁二烯苯乙烯共聚物 (ABS)。 過濾膜之材質亦無特別之限制，可適當選擇聚砜 (PS)、聚偏二氟乙烯(PVDF)等。且，過濾膜之構造若為多 孔物質則亦無特別之限制。過濾膜表面之細孔徑亦無特別 之限制，但宜使用Ο.ΟΙμιη以上、20μιη以下程度者。 過濾水喷嘴係用以嵌合連結過濾膜元件與過濾膜模組 之集水管之管體者，乃與板體一體進行射出成形所得。又， 過濾水流道槽係於板體之表背面上與過濾水喷嘴連通而形 成複數條之槽。藉過濾膜而得之過濾膜元件内部之處理水 將流經過濾水流道槽而流入過濾水喷嘴，並經管體而集中 於過濾膜模組之集水管。 本發明之過濾膜元件一如第1圖所示，其特徵在於板體 之上端部5包含愈接近前端厚度愈小之形狀之部分。 板體之上端部包含愈接近前端厚度愈小之形狀，故如 201236747 - 第2圖所示，可使通過相隣之板體之間之迴旋流之流道徐緩 擴大，並避免迴旋流通過板體之上端部時發生卡門滿。藉 此，而可減少板體之兩面之差壓，並減少過濾膜元件之振 動。 板體之上端部5包含愈接近前端厚度愈小之形狀之例 一如第5(a)〜5(e)圖所示，可舉出上端部之整體呈愈接近前 端厚度愈小之形狀。第1圖及第5(a)圖即板體之上端部5設有 過濾水噴嘴4，而過濾水喷嘴4除外之板體之上端部5之整體 形成錐狀之例。第5(b)〜5(d)圖則係板體之上端部5之整體形 成錐狀之例，第5(b)圖及第5(c)圖係過濾水喷嘴4與板體之 上端部5—體化之形狀，第5(d)圖係過濾水喷嘴4形成於板體 2之側面上之形狀。 在此，所謂錐狀，係指板體之兩面或單面形成具有一 定之傾斜角之斜面，且隨著接近前端而使厚度依一定比例 減小而成之形狀。斜面之傾斜角則稱為錐角度。錐角度可 在板體之兩面上相同，亦可不同。 呈錐狀時，錐角度在較小範圍内無法避免卡門渦之發 生’但大於某個角度即可避免卡門渦之發生。該角度係隨 板體之厚度、上端部之高度(過濾膜之上端緣至板體之上端 緣之距離）、相隣之板體之間隔等過濾膜元件之各尺寸及迴 旋流之速度及密度等過濾膜模組之運轉之各條件而不同。 錐角度過大並無優點’並可能發生板體之厚度減小所致之 剛性降低、碎裂及龜裂等’故宜在不致發生卡門渦之範圍 内先加以控制在最小限度之角度。 201236747 又’本發明不限於錐狀，亦可考量採用諸如第5(e)圖所 示之拋物線形狀n就板體2之射出成形所使用之模具 之加工性之觀點而言則宜制錐狀^即便㈣錐狀，亦與 習知之形狀相同’就射出成形時之產品與模具之擦傷防止 及產品之安全性之觀點而言，端緣宜略經倒圓角處理。 又，如第5(f)圖所示，亦可不使上端部之整體而使其局 部包含愈接近前端厚度愈小之形狀之部分。 板體之上端部之形狀就活性污泥槽内整體之迴旋流之 均-性之觀點而言，宜在板體之兩面上呈對稱形狀。尤其 在上端部之形狀為錐狀時，錐角度宜在兩面上均相同。 實施例 刀别製作U片概略尺寸為南800mmx寬240mmx厚 6mm ’上端部形成第7⑷〜7(c)圖所示之3種形狀之abs樹脂 製之板體2 〇第7刚所示者乃習知之形狀之形成矩形形狀 之上端部14。第7(b)圖所示者乃其整體形成愈接近前端厚度 愈小之形狀之上端部15。第7(c)圖所示者乃其局部形成愈接 近前端厚度愈小之形狀之上端部16。 使該等各11片之3組之板體構成使相隣之板體之間隔 為8.5mm而就各組加以裝填於下部設有散氣裝置之過濾膜 模組中’再加以固設於寬700mmx深270mmx高1500mm之透 明水槽内’並加入清水至液面較過濾膜模組之頂部高 3〇〇mm而加以浸入’再朝散氣裝置就每片過濾膜元件導入 7.5公升/分鐘之空氣而進行運轉。 第1實施例 10 201236747 以高速攝影機拍攝11片中配置於中央之板體之上端部 附近之迴旋流之狀態’而觀察板體之上端部之形狀所致之 迴旋流之變化。 其結果，已就上端部14觀測到板體之上端部之上方之 卡門渦之發生。另’就上端部16雖已確認略微發生板體之 上端部之上方之卡門渦，但就上端部15則未確認發生板體 之上端部之上方之卡門渦，上端部15、16之通過上端部之 迴旋流與上端部14相較之下均較為順暢。 第2實施例 由板體表面之應變大小計算11片中配置於中央之板體 之上端部所承受之彎矩大小，並比較板體之上端部之形狀 所致之振動負載之變化。於距板體之上端緣25mm之下方、 距板體之側緣120mm(板體之中心線上）、6〇mm之2部位之表 面上，分別黏著固定1軸之水中用應變測量計，而使其軸同 於板體之寬度方向，並匯入上述2部位之應變之波形資料。 再由該波形資料求出應變之振幅ε，而算出將對板體作用之 彎矩Μ。 彎矩M(N . mm)=2xExIxs/h 其中， E :板體之縱彈性係數(MPa) I .板體之截面2次力矩(mm4) h :板體之厚度(mm) 其結果’則如第8圖所示，板體所承受之彎矩大小與習 知之上端部14相較，已確認上端部15減為66% ，上端部16 11 201236747 則減為77%。 如上，已顯不構成包含愈接近前端厚度愈小之形狀之 部分之上端部，即可獲致振動之抑制效果。尤其，亦顯示 了與其局部愈接近前端厚度愈小之上端部相較，則其整體 愈接近則端厚度愈小之上端部之效果更為明顯。其等僅變 更板體之上端部之形狀，故與需要追加構件之構造相較， 成本及組裝作業性、可靠性較佳。 以上已詳細或參照特定實施態樣而說明本發明，但在 不逸脫本發明之主旨與範圍之限度内，可追加各種變更及 修正，凡本技術領域從業人員應可得而知。 本案申請係以2010年12月15日提申之日本專利申請 2010-279077號為依據，而將其内容參照引用於本說明書 中。 產業上之可利用性 將本發明之過濾膜元件設於過濾膜模組内並加以浸入 活性污泥槽内而加以使用，即可避免過濾膜元件之板體之 上端部之上方之卡門渦之發生，旅減少板體之兩面之差壓 而減少振動。 【圖式簡單說明】 第1圖係例示本發明之過濾膜元件者。 第2圖係係顯示本發明之過濾膜元件之上端部與迴旋 流者。 第3圖係例示習知之過濾膜元件者。 第4圖係顯示習知之過濾膜元件之上端部與迴旋流者。 12 201236747 第5 (a)〜5⑴圖係顯示本發明之過濾膜元件之他例者。 第6圖係例示過渡膜模組者。 第7(a)〜7(c)圖係顯示實施例所使用之板體之上端部之 形狀者。 第8圖係顯示實施例之結果者。 【主要元件符號說明】 1...過濾膜元件 8...過濾膜模組 2...板體 9...活性污泥槽 3...過濾膜 10…幫浦 4...過濾水喷嘴 11...散氣裝置 5...上端部 12...送風機 6...迴旋流 13...集水管 7...卡門渦 14、15、16____L端部 13The transition film element according to (1) or (2), wherein the upper end portion has a symmetrical shape on both surfaces of the plate body. (4) The filter membrane element according to any one of (1) to (3), wherein the upper end portion as a whole has a shape closer to a thickness of the tip end. (5) A transition film module comprising: the transition film element of any one of (1) to (4), disposed in a plurality of frames; and a diffusing device disposed under the filter element . Further, the term "substantially parallel" as used in the present specification encompasses the concept of the effect of the present invention as parallel, even if it is not truly parallel. Advantageous Effects of Invention When the filter membrane element of the present invention is placed in a filtration membrane module and immersed in an activated sludge tank, the Karman vortex above the upper end of the plate body of the filtration membrane element can be avoided and borrowed. Reduce the differential pressure on both sides of the board and reduce vibration. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a filter membrane element of the present invention. Fig. 2 is a view showing the upper end portion and the swirling flow of the filtration membrane element of the present invention. Fig. 3 is a view showing a conventional filter membrane element. Figure 4 is a diagram showing the upper end and the swirling flow of a conventional filter membrane element. Figures 5(a) to 5(1) show other examples of the filter membrane element of the present invention. Fig. 6 is a diagram showing a filter membrane module. The seventh (a) to (c)th drawings show the shape of the upper end portion of the plate body used in the embodiment. 201236747 Figure 8 shows the results of the examples. I: Embodiment 3 In order to carry out the invention, as shown in Fig. 1, the filter membrane element of the present invention forms a filtered water nozzle 4 at the end edge, and is formed with a filtered water flow channel groove (not shown) A filter membrane 3 is disposed on both sides of the plate body 2 . The material constituting the plate body is not particularly limited, but in view of mass production, cost, and weight reduction, it is generally preferable to select a resin suitable for injection molding. Further, it is preferable to use an excellent chemical resistance to avoid attack by various substances contained in the wastewater, and generally an acrylonitrile butadiene styrene copolymer (ABS) is used. The material of the filtration membrane is not particularly limited, and polysulfone (PS), polyvinylidene fluoride (PVDF), or the like can be appropriately selected. Further, the structure of the filtration membrane is not particularly limited as long as it is a porous substance. The pore diameter of the surface of the filtration membrane is not particularly limited, but it is preferably Ο.ΟΙμη or more and 20 μmη or less. The filtered water nozzle is obtained by fitting and integrating the filter film element and the water collecting pipe of the filter membrane module, and integrally forming the same with the plate body. Further, the filtered water flow channel groove is connected to the filtered water nozzle on the front and back surfaces of the plate body to form a plurality of grooves. The treated water inside the filter membrane element obtained by the filter membrane flows through the filtered water flow channel and flows into the filtered water nozzle, and is concentrated on the water collecting pipe of the filtration membrane module through the tubular body. The filter membrane element of the present invention, as shown in Fig. 1, is characterized in that the upper end portion 5 of the plate body contains a portion having a shape closer to the thickness of the front end. The upper end of the plate body has a shape closer to the thickness of the front end, so as shown in 201236747 - Fig. 2, the flow path through the swirling flow between adjacent plates can be gradually expanded, and the swirling flow can be prevented from passing through the plate. The Carmen is full when the upper end of the body. Thereby, the differential pressure between the two sides of the plate body can be reduced, and the vibration of the filter membrane element can be reduced. The upper end portion 5 of the plate body includes a shape having a shape closer to the thickness of the tip end. As shown in Figs. 5(a) to 5(e), the entire upper end portion has a shape which is smaller toward the front end. Figs. 1 and 5(a) show an example in which the upper end portion 5 of the plate body is provided with a filtered water nozzle 4, and the upper end portion 5 of the plate body except the filtered water nozzle 4 is formed into a tapered shape. 5(b) to 5(d) are examples in which the entire upper end portion 5 of the plate body is tapered, and the fifth (b) and fifth (c) drawings are the filtered water nozzle 4 and the upper end of the plate body. The shape of the portion 5 is formed, and the fifth (d) is a shape in which the filtered water nozzle 4 is formed on the side surface of the plate body 2. Here, the term "tapered" means that the two sides or one side of the plate body are formed with a slope having a certain inclination angle, and the thickness is reduced by a certain ratio as the front end is approached. The angle of inclination of the slope is called the cone angle. The taper angle can be the same on both sides of the board or different. When it is tapered, the cone angle cannot be avoided in a small range. However, it is greater than a certain angle to avoid the occurrence of the Karman vortex. The angle is the thickness of the plate body, the height of the upper end portion (the distance from the upper edge of the filter film to the upper edge of the plate body), the spacing between adjacent plates, and the size and velocity of the swirling flow. The conditions for the operation of the filter membrane module vary. If the taper angle is too large, there is no advantage, and the rigidity reduction, chipping, cracking, etc. due to the reduction of the thickness of the plate body may occur. Therefore, it is preferable to control the minimum angle within the range where the Karman vortex does not occur. 201236747 Further, the present invention is not limited to the tapered shape, and it is also possible to adopt a parabolic shape n such as shown in Fig. 5(e), and it is preferable to form a taper from the viewpoint of the workability of the mold used for the injection molding of the plate body 2. ^ Even if the (four) taper shape is the same as the conventional shape, the edge should be slightly rounded from the viewpoint of the scratch prevention of the product and the mold at the time of injection molding and the safety of the product. Further, as shown in Fig. 5(f), the entire portion of the upper end portion may not include a portion having a shape closer to the thickness of the front end. The shape of the upper end portion of the plate body is preferably symmetrical on both sides of the plate body from the viewpoint of the uniformity of the entire swirling flow in the activated sludge tank. In particular, when the shape of the upper end portion is tapered, the taper angle should be the same on both sides. In the example, the shape of the U-piece is approximately 800 mm x 240 mm x 6 mm thick. The upper end is formed into a plate of the three types of abs resin shown in the seventh (4) to 7 (c). The conventional shape forms an end 14 of a rectangular shape. The figure shown in Fig. 7(b) is the upper end portion 15 of the shape in which the whole shape is formed to be closer to the thickness of the front end. The figure shown in Fig. 7(c) is the upper end portion 16 of the shape in which the partial formation is closer to the thickness of the front end. The plates of the 11 groups of the 11 pieces are formed so that the distance between the adjacent plates is 8.5 mm, and the groups are loaded in the filter film module having the diffusing device at the lower portion, and then fixed in the width. 700mmx deep 270mmx 1500mm high transparent water tank' and add water to the liquid surface 3 inches higher than the top of the filter membrane module and immersed in it. Then introduce 7.5 liters/min of air into each filter membrane element. And it works. First Embodiment 10 201236747 A high-speed camera photographs the state of the swirling flow near the upper end portion of the upper portion of the central plate in 11 sheets, and observes the change in the swirling flow caused by the shape of the upper end portion of the plate body. As a result, the occurrence of the Karman vortex above the upper end portion of the plate body has been observed with respect to the upper end portion 14. Further, although the upper end portion 16 has confirmed that the Karman vortex slightly above the upper end portion of the plate body has occurred, the upper end portion 15 does not confirm the occurrence of the Karman vortex above the upper end portion of the plate body, and the upper end portions 15 and 16 pass through the upper end portion. The swirling flow is smoother than the upper end portion 14. (Second Embodiment) The magnitude of the bending moment received by the upper end portion of the 11-piece plate body at the center of the plate body was calculated from the strain amount on the surface of the plate body, and the change in the vibration load due to the shape of the upper end portion of the plate body was compared. The strain gauge is fixed to the water of one axis at a distance of 25 mm from the upper edge of the plate body, 120 mm from the side edge of the plate body (the center line of the plate body), and 2 parts of the surface of 6 mm. The axis is the same as the width direction of the plate body, and the strain waveform data of the above two parts is merged. Further, from the waveform data, the amplitude ε of the strain is obtained, and the bending moment 将 which acts on the plate body is calculated. Bending moment M(N . mm)=2xExIxs/h where E is the longitudinal elastic modulus (MPa) of the plate body I. The second moment of the section of the plate body (mm4) h : the thickness of the plate body (mm) The result is ' As shown in Fig. 8, the bending moment of the plate body is compared with the conventional upper end portion 14, and it has been confirmed that the upper end portion 15 is reduced to 66%, and the upper end portion 16 11 201236747 is reduced to 77%. As described above, it has been shown that the end portion of the portion including the shape having a smaller thickness toward the front end is formed, and the vibration suppressing effect can be obtained. In particular, it is also shown that the closer the thickness is to the end portion, the closer the thickness is to the upper end portion, and the closer the overall thickness is, the smaller the end thickness is. Since only the shape of the upper end portion of the plate body is changed, the cost, assembly workability, and reliability are better than those of the structure requiring additional members. The present invention has been described in detail above with reference to the specific embodiments thereof. However, various modifications and changes may be made without departing from the spirit and scope of the invention. The application of the present application is based on Japanese Patent Application No. 2010-279077, filed on Dec. 15, 2010, the content of which is hereby incorporated by reference. INDUSTRIAL APPLICABILITY The filter membrane element of the present invention is disposed in a filter membrane module and immersed in an activated sludge tank to avoid the Karman vortex above the upper end portion of the membrane element of the filtration membrane element. Occurs, the brigade reduces the pressure difference between the two sides of the board and reduces vibration. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a filter membrane element of the present invention. Fig. 2 is a view showing the upper end portion and the swirling flow of the filtration membrane element of the present invention. Fig. 3 is a view showing a conventional filter membrane element. Figure 4 is a diagram showing the upper end and the swirling flow of a conventional filter membrane element. 12 201236747 Sections 5(a) to 5(1) show other examples of the membrane element of the present invention. Figure 6 is a diagram illustrating a transition film module. The seventh (a) to (c)th drawings show the shape of the upper end portion of the plate body used in the embodiment. Figure 8 shows the results of the examples. [Description of main component symbols] 1...Filter membrane element 8...Filter membrane module 2...plate body 9...activated sludge tank 3...filter membrane 10...helper 4...filter Water nozzle 11... diffusing device 5... upper end portion 12... blower 6... swirling flow 13... water collecting tube 7... Karman vortex 14, 15, 16-1L end portion 13