外文翻譯--現(xiàn)代帶式輸送機(jī)系統(tǒng)

1、<p><b>　　現(xiàn)代帶式輸送機(jī)系統(tǒng)</b></p><p>　　克.洛德維基斯荷蘭代爾夫特科技大學(xué)學(xué)院的設(shè)計，工程及生產(chǎn)</p><p><b>　　簡介</b></p><p>　　皮帶輸送機(jī)已使用了超過150年。采用皮帶傳送的散裝固體材料的概念并沒有真正改變傳送機(jī)的特點(diǎn)。大多數(shù)的研究一直側(cè)重于改善和輸送

2、部件上的皮帶的加固材料和橡膠化合物的優(yōu)化。然而今天，人們可以區(qū)別開和關(guān)之間輸送系統(tǒng)傳統(tǒng)的開放式皮帶輸送機(jī)系統(tǒng)的帶槽形和散裝固體物質(zhì)直接接觸空氣，（雖然總輸送機(jī)可附后）。封閉的輸送系統(tǒng)，帶包含了大量的材料，從而消除了粉塵污染的風(fēng)險。</p><p><b>　　圖 1</b></p><p>　　新的管道輸送體統(tǒng)，包含龍門三角概念</p><p>

3、;　　本文將討論國家最先進(jìn)的封閉皮帶輸送機(jī)系統(tǒng)設(shè)計，并會強(qiáng)調(diào)開和關(guān)之間皮帶輸送系統(tǒng)中最重要的區(qū)別。下面將討論的主題:</p><p>　　皮帶輸送機(jī)的設(shè)計和施工要求，</p><p><b>　　輸出適宜性， </b></p><p>　　輸送裝卸程序和制度， </p><p>　　輸送帶幾何特別是橫向和縱向曲線設(shè)計，

4、</p><p>　　輸送機(jī)的結(jié)構(gòu)設(shè)計， </p><p>　　輸送機(jī)驅(qū)動系統(tǒng)，特別是能源消耗， </p><p>　　環(huán)境影響皮帶輸送機(jī)。 </p><p>　　傳統(tǒng)的帶式輸送機(jī)要和袋形與管道輸送的特點(diǎn)進(jìn)行討論來得出結(jié)論。這些圖片1、2和3顯示的基本構(gòu)造帶式輸送機(jī)的兩種封閉的概念。這些圖1和2描繪了同一袋形的輸送存在有關(guān)的皮帶構(gòu)造及驅(qū)動技術(shù)

5、的根本分歧,在第二章將詳細(xì)講解。</p><p><b>　　圖 2</b></p><p>　　Enerka-Becker 系統(tǒng)</p><p><b>　　圖 3</b></p><p><b>　　Sicon系統(tǒng)</b></p><p><b

6、>　　圖 4</b></p><p><b>　　管道輸送</b></p><p>　　輸送帶的設(shè)計和施工要求</p><p>　　在介紹中提到三者之間的皮帶的概念主要區(qū)別在于皮帶構(gòu)造。本節(jié)討論的典型皮帶構(gòu)造。</p><p><b>　　傳統(tǒng)的輸送帶</b></p>

7、<p>　　傳統(tǒng)的輸送帶已經(jīng)發(fā)展了多年，現(xiàn)在拉力運(yùn)作高達(dá)1000千牛頓/米（或N/ mm）。他們的結(jié)構(gòu)可以完整的纖維，鋼電纜或鋼基體，一種合金鋼和纖維，或者甚至一個壟斷纖維結(jié)構(gòu)。典型的屠體部分如圖。</p><p><b>　　圖 5</b></p><p><b>　　多層纖維構(gòu)造</b></p><p

8、><b>　　圖6</b></p><p><b>　　壟斷構(gòu)造</b></p><p><b>　　圖 7</b></p><p><b>　　鋼電纜構(gòu)造</b></p><p><b>　　圖 8</b></p>

9、<p><b>　　鋼基體構(gòu)造</b></p><p><b>　　袋形輸送帶</b></p><p>　　這兩個不同的袋形帶外在構(gòu)造體現(xiàn)了承受的不同壓力，與sicon結(jié)構(gòu)使用鋼纜張力共同提供10千牛典型繩張力，Enerka-Becker系統(tǒng)（EBS）的是一個總纖維/橡膠結(jié)構(gòu)帶來的一個最大操作張力的大約10牛頓/平方毫米。</

10、p><p>　　兩個系統(tǒng)之間的根本區(qū)別是:</p><p>　　在EBS中皮帶的軸向剖面沒有加固，皮帶軸的SICON型材里面有鋼絲束縛。 </p><p>　　SICON皮帶的主體沒有EBS的皮帶主體包括纖維加固補(bǔ)強(qiáng)。 </p><p>　　在EBS的皮帶和皮帶的橡膠蓋一塊形成一個軸向剖面。在SICON皮帶和皮帶的主體軸向剖面兩件（熱）硫化在一起

11、。更多關(guān)于袋皮帶輸送機(jī)的信息可以在[1] 中找到。</p><p><b>　　管輸送帶</b></p><p>　　管道傳送帶是基于傳統(tǒng)的皮帶輸送機(jī)的結(jié)構(gòu)設(shè)計的。構(gòu)造物和以及鋼鐵混凝土都可以使用。但是有兩個概念之間的細(xì)微差別。.</p><p><b>　　圖 9</b></p><p><

12、b>　　典型纖維結(jié)構(gòu)</b></p><p><b>　　圖10</b></p><p><b>　　典型鋼斜拉橋結(jié)構(gòu)</b></p><p>　　圖4顯示了截面管的輸送帶通過管道，表明皮帶必須能形成一個完整的圓形或橢圓形從而形成重疊/密封。圖9和圖10表明皮帶結(jié)構(gòu)是這樣的：在重疊部分，也就是兩個邊緣部分

13、的彎曲剛度比皮帶的中心彎曲剛度低。</p><p><b>　　適宜輸送機(jī)</b></p><p>　　三種的皮帶輸送機(jī)的概念都不會所有應(yīng)用程序所接受，圖11可以用來區(qū)分這地區(qū)的適用性,塊狀會計為容積大小,和傾斜角度。</p><p><b>　　圖 11</b></p><p>　　在圖的區(qū)域適宜

14、性1米/秒</p><p>　　圖11已顯示出的能力范圍為不同的帶式輸送機(jī)的類型。關(guān)閉輸送系統(tǒng)的能力取決于一些參數(shù)如下:</p><p><b>　　皮帶的橫截面面積 </b></p><p>　　該區(qū)域可填補(bǔ)（最大裝載度）面積的百分比。最大容量的填充度通常在50-60％之間。 </p><p>　　整塊大小的散裝固體材

15、料(如圖11)。最大的整塊的大小是約三分之一的管道或袋形的直徑。 </p><p>　　重量限制條件的最大重量米/皮帶</p><p>　　皮帶速度(如圖11) </p><p>　　圖12顯示了在1米/秒，平均作為管道或囊直徑功能容積。一般來說一個封閉的輸送系統(tǒng)需要一個50%寬皮帶相對應(yīng)，傳統(tǒng)的開放式皮帶輸送機(jī)系統(tǒng)要達(dá)到同樣的容量需要增加20%的成本才能得到加強(qiáng)。

16、此規(guī)則正在嚴(yán)重制約與皮帶速度提高，它已成為可能，因?yàn)橛懈哔|(zhì)量的惰輪來加快控制系統(tǒng)的開發(fā)。袋型皮帶限制于較低的能力, 因?yàn)楸池?fù)系統(tǒng)的惰輪。它通常有一個最大容量大約400到500立方米/ hr在3到4米/秒。目前被認(rèn)為最大的使用800毫米直徑的管道皮帶能夠傳達(dá)到4000 m3/hr。</p><p><b>　　圖 12</b></p><p>　　在皮帶速度

17、為1米/秒關(guān)閉輸送系統(tǒng)的能力</p><p>　　輸送機(jī)加載和卸載程序</p><p>　　傳統(tǒng)的皮帶輸送機(jī)和管道裝載和卸載的方法完全一樣，正在為傳統(tǒng)的帶式進(jìn)料系統(tǒng)從尾部打開皮帶輪，并再次開放在頭排皮帶輪。</p><p><b>　　圖 13</b></p><p><b>　　管料皮帶輸送和關(guān)閉</b

18、></p><p><b>　　圖 14</b></p><p><b>　　管帶開放和排出</b></p><p>　　然而帶型皮帶負(fù)荷安排使用了更嚴(yán)格的類型，但可能有類似的排放到其他系統(tǒng)。所有的傳統(tǒng)裝車點(diǎn)劣勢被淘汰的郵袋安全帶溢出和偏心荷載不應(yīng)該發(fā)生的。但現(xiàn)在變成了超載的重大關(guān)切，這個問題也通過對管道進(jìn)行輸送。重

19、要的是，無論是郵袋和管道輸送機(jī)有一個控制喂點(diǎn)，以確保沒有超載的發(fā)生。這通常是通過使用控制的饋線及重載限位開關(guān)。這使得管道和袋型皮帶裝置不合格，如在破碎機(jī)排放點(diǎn)的地方激增的情況非常普遍。另一種與袋輸送機(jī)的關(guān)注點(diǎn)是散裝物料的水分含量。在傳統(tǒng)槽形皮帶輸送機(jī)讓水分流失，在頭部或尾部帶皮帶輪，一小袋輸送機(jī)是在裝貨點(diǎn)完全關(guān)閉。如果頭皮帶輪位于比高于裝車點(diǎn)帶可能充滿了水，它可以處理本身的問題。</p><p><b>

20、;　　圖 15</b></p><p><b>　　袋料皮帶</b></p><p><b>　　圖 16</b></p><p>　　袋型皮帶排放：水平排放</p><p><b>　　幾何輸送帶</b></p><p>　　除了所有的環(huán)境

21、效益，對封閉的皮帶輸送系統(tǒng)中最重要的優(yōu)勢之一是能夠圍繞小半徑曲線運(yùn)行。在傳統(tǒng)的開放式皮帶輸送機(jī)系統(tǒng)的曲線半徑主要取決于在曲線皮帶張力。在水平曲線的曲線半徑應(yīng)足夠大，以防止，加上銀行的角度，從流失托輥皮帶應(yīng)用。在豎曲線半徑應(yīng)足夠大，以防止帶升空的凹曲線，并限制在惰輪凸曲線的負(fù)荷。進(jìn)一步曲線半徑應(yīng)該是這樣，隨著皮帶張力的曲線，帶既不是過度緊張，也不能受壓表決。通常是一個傳統(tǒng)的平曲線半徑為開放帶輸送1000至2000米。在一個開放的皮帶輸送機(jī)

22、的垂直變化曲線半徑一般400至800米。封閉的皮帶輸送系統(tǒng)在惰輪一般要小得多非公開皮帶輸送系統(tǒng)中使用的間距。在一個封閉的皮帶輸送系統(tǒng)曲線半徑，因此主要取決于受理帶伸展。此外，一個曲線半徑應(yīng)足夠大，以保持帶的典型截面（一管應(yīng)留一管），穩(wěn)定中的惰輪帶（對中應(yīng)防止管道輸送管旋轉(zhuǎn)）的立場。惰輪皮帶流失不是一個封閉式皮帶輸送機(jī)系統(tǒng)的問題，因?yàn)闊o論是總帶或帶的軸向剖面鎖在惰輪了。</p><p><b>　　圖

23、17</b></p><p>　　平曲線半徑的不同典型帶式輸送機(jī)</p><p>　　圖17顯示了典型的封閉式皮帶輸送機(jī)惰輪支持的系統(tǒng)平曲線半徑。正如在看到這個數(shù)字所需的半徑小于一半或等于未使用的皮帶輸送系統(tǒng)半徑的三分之一。Enerka- Becker系統(tǒng)的袋型皮帶輸送機(jī)，是在這方面與典型的平曲線半徑的僅是一個開放式皮帶輸送機(jī)所需的半徑分?jǐn)?shù)方面的優(yōu)勢。</p>&

24、lt;p><b>　　圖18</b></p><p><b>　　典型的彎曲囊輸送臺</b></p><p><b>　　圖 19</b></p><p><b>　　彎曲的細(xì)皮帶輪</b></p><p>　　一個進(jìn)一步的減少對水平曲線半徑為一袋帶

25、式輸送機(jī)甚至可能由惰輪取而代之。在這種情況下的半徑水平曲線可以少于一米假設(shè)皮帶的不完全載入。也見圖18和圖19。對于一個封閉的皮帶輸送系統(tǒng)圖17豎曲線半徑的確定是需要的并且很好, 但是袋形EP或EBS的輸送皮帶線在這種情況下，與管道輸送EP皮帶線重合。帶式輸送機(jī)相比傳統(tǒng)的開放系統(tǒng)關(guān)閉系統(tǒng)允許帶式輸送機(jī)垂直曲線半徑的實(shí)質(zhì)上減小。.</p><p><b>　　圖 20</b></p>

26、;<p>　　管道輸送適宜半徑300米和90度曲線</p><p>　　對于非常小半徑曲線，在輸送機(jī)的鋼筋袋袋屈曲難以避免。在承載鋼筋節(jié)，這旁邊的軸向剖面，將永遠(yuǎn)不會扣。承載能力大，因此不會受到影響。經(jīng)驗(yàn)表明，袋形皮帶是不是因?yàn)榍茐?。但是它的容量減少。非常小半徑曲線路段因此大多應(yīng)用于皮帶在身上沒帶負(fù)荷。非增強(qiáng)袋輸送機(jī)沒有責(zé)任的皮帶屈曲。然而他們易疲勞損傷敏感。</p><p&

27、gt;　　輸送管道的屈曲不過是不能接受的，因?yàn)樗粌H嚴(yán)重降低了其能力，還它可能會損壞成員以及承載。管道輸送皮帶因此必須有足夠的力量承受屈曲時形成緊密的縱向和橫向曲線.</p><p><b>　　輸送機(jī)的結(jié)構(gòu)設(shè)計</b></p><p>　　考慮到所有類型的輸送系統(tǒng)的結(jié)構(gòu)設(shè)計未來幾年將發(fā)生一個巨大的革命，消除為盡可能多的結(jié)構(gòu)。囊輸送進(jìn)去鋼結(jié)構(gòu)量減少百分之材料每噸需要一

28、個很長的路要走傳達(dá)和圖21顯示了如何簡單的建設(shè)可制成。該Enerka - Becker系統(tǒng)的特點(diǎn)是非常低的張力局勢，由于帶了一個獨(dú)特的多驅(qū)動系統(tǒng)的應(yīng)用。低帶的緊張局勢使小半徑平曲線和一個非常輕盈飄逸的支撐結(jié)構(gòu)。結(jié)構(gòu)上有許多可供選擇。當(dāng)前所安裝的系統(tǒng)布局如圖21。這個方案的整體尺寸是在一個1米× 1米范圍另一個選擇是兩個以上的位置互相帶部分地區(qū)。</p><p><b>　　Figure 21&

29、lt;/b></p><p><b>　　典型的EBS的截面</b></p><p><b>　　圖 22</b></p><p>　　典型Enerka- Becker布局</p><p><b>　　環(huán)境影響</b></p><p>　　當(dāng)考慮到

30、開啟和關(guān)閉的輸送線以下的環(huán)境優(yōu)勢存在于封閉輸送設(shè)備:</p><p>　　周圍塵埃不能發(fā)展，因?yàn)樵谶\(yùn)輸過程中的大部分固體物質(zhì)，在封閉的皮帶鎖定。環(huán)境粉塵發(fā)展，可以是一個重大的問題時，運(yùn)送糧食，水泥等細(xì)顆粒材料。</p><p>　　政府法規(guī)已經(jīng)開始應(yīng)用或資助他們的無塵輸送系統(tǒng)的安裝.</p><p>　　如果輸送帶鏈的回應(yīng)也關(guān)閉，那么沒有散裝固體物質(zhì)可以建立下面的傳

31、送帶。這可能是一個與傳統(tǒng)的主要問題，槽形皮帶輸送系統(tǒng)輸送時，粘壤土等材料。在一個傳統(tǒng)的皮帶輸送機(jī)排放點(diǎn)這種材料將部分粘在皮帶導(dǎo)致積聚在回滾筒和其他機(jī)械部件。這不能完全避免，甚至不帶刮時使用。此外，帶刮刀可導(dǎo)致皮帶蓋磨損。</p><p>　　關(guān)閉輸送系統(tǒng)能使垂直和水平的小半徑曲線,然后打開帶式輸送機(jī)。這是一個很大的好處,只有很小的地方可再擺一個輸送系統(tǒng)。</p><p>　　封閉輸送系統(tǒng)比

32、傳統(tǒng)的陡傾角允許，槽形（非異型）輸送帶。這樣做的主要理由是，帶鎖定散裝物料造成較高的散裝材料的內(nèi)部壓力。這增加了的意思，一個比正常陡傾角為起始原料需要跑回來材料內(nèi)部的摩擦。阿非異型帶具有最高約17度傾角。如雪佛龍德士古實(shí)皮帶、腰帶、或高雪佛龍德士古公司可以用更陡傾斜角度如果是必要的。在許多應(yīng)用領(lǐng)域,然而,異型傳送帶很難被應(yīng)用。</p><p>　　由于能夠通過小半徑曲線運(yùn)行，封閉的輸送系統(tǒng)，我們認(rèn)為，在轉(zhuǎn)機(jī)處只應(yīng)

33、該有一個原因，“我們別無選擇。“在轉(zhuǎn)機(jī)處是失敗，損壞，功率損耗，勞動消耗，高環(huán)境影響的最大原因。一個方向的轉(zhuǎn)變并不意味著一個中轉(zhuǎn)站。t.</p><p><b>　　結(jié)論</b></p><p><b>　　鳴謝</b></p><p>　　非常感謝輸送機(jī)知識和信息技術(shù)中心委員會主席P. Staples先生，在筆者完成本論

34、文過程中所給予的幫助。</p><p><b>　　參考文獻(xiàn)</b></p><p>　　克.洛德維基斯的研究和封閉皮帶輸送系統(tǒng)與散裝固體處理，卷20，2000，第465-470頁。</p><p>　　Modern Belt Conveyor Systems</p><p>　　G. LodewijksFaculty

35、 of Design, Engineering and Production, Delft University of Technology, the Netherlands</p><p>　　INTRODUCTION</p><p>　　Belt conveyors have been used for over 150 years. The concept of conveying

36、bulk solid materials by belt, however, has not really changed. Most research has been focused on the improvement of conveyor components and on the optimization of the belt’s reinforcement material and rubber compounds. T

37、oday however, one can differentiate between open and closed conveyor systems. In conventional open belt conveyor systems the belt is troughed and the bulk solid material is in direct contact with the air, </p><

38、;p><b>　　Figure 1</b></p><p>　　New pipe conveyor system incorporating triangular gantry concept</p><p>　　This paper will discuss the state-of-the-art in closed belt conveyor system

39、 design, and will highlight the most important differences between open and closed belt conveyor systems. The following topics will be discussed:</p><p>　　conveyor belt design and construction requirements,

40、</p><p>　　conveyor suitability, </p><p>　　conveyor loading and unloading procedures and systems, </p><p>　　conveyor geometry in particular the design of horizontal and vertical curv

41、es, </p><p>　　conveyor structure design, </p><p>　　conveyor drive systems, in particular the energy consumption, </p><p>　　environmental impact of belt conveyors. </p><p&

42、gt;　　The characteristics of a conventional belt conveyor will be compared with those of both the pouched and pipe conveyor to discuss the above mentioned topics. The figures 1, 2, & 3 show the basic construction of t

43、he two closed belt conveyor concepts. Although the figures 1 and 2 depict the same principal of pouch conveyors, there are fundamental differences relating to the belt construction and drive techniques, as will be explai

44、ned in section 2.</p><p><b>　　Figure 2</b></p><p>　　Enerka-Becker System</p><p><b>　　Figure 3</b></p><p>　　Sicon System</p><p><

45、b>　　Figure 4</b></p><p>　　Pipe Conveyor System</p><p>　　CONVEYOR BELT DESIGN AND CONSTRUCTION REQUIREMENTS</p><p>　　The main difference between the three belt concepts ment

46、ioned in the introduction is the construction of the belt. This section discusses typical belt constructions.</p><p>　　Conventional Conveyor Belt</p><p>　　Conventional conveyor belting has devel

47、oped over the years and today operates at tensions as high as 1000 kN/m (or N/mm) width. Their construction can be full fabric, steel cable or steel matrix, a combination of the steel and fabric, or even a monopoly fabri

48、c construction. Typical carcass sections are shown in figures.</p><p><b>　　Figure 5</b></p><p>　　Multiply fabric construction</p><p><b>　　Figure 6</b></p&

49、gt;<p>　　Monoply construction</p><p><b>　　Figure 7</b></p><p>　　Steel Cable Construction</p><p><b>　　Figure 8</b></p><p>　　Steel matrix c

50、onstruction</p><p>　　Pouch Type Conveyor Belt</p><p>　　The two pouch belt options differ in their appearance by the construction of the tension number, with the Sicon using a steel cable tension

51、 member offering a typical rope tension of 10 kN and the Enerka-Becker System (EBS) being a total fabric/rubber construction having a maximum operating tension of about 10 N/mm.</p><p>　　The basic difference

52、 between the two systems are:</p><p>　　The axial profiles of the EBS belt have no reinforcement, the axial profiles of the SICON belt have a steel cord inside. </p><p>　　The main body of the SIC

53、ON belt has no reinforcement whereas the main body of the EBS belt includes fabric reinforcement. </p><p>　　The axial profiles of the EBS belt and the belt’s rubber cover form one piece. The axial profiles o

54、f the SICON belt and the main body of the belt are two pieces (warm) vulcanized together.More information on pouch belt conveyors can be found in [1]. </p><p>　　Pipe Conveyor Belt</p><p>　　The p

55、ipe conveyor belt is based on the construction of the conventional belt conveyor. Both fabric and as well as steel reinforcing can be used. However there are subtle differences between the two concepts.</p><p&

56、gt;<b>　　Figure 9</b></p><p>　　Typical Fabric Construction</p><p><b>　　Figure 10</b></p><p>　　Typical steel Cable Construction</p><p>　　Figure 4

57、shows the cross section of the pipe conveyor belt through the pipe indicating that the belt must be capable of forming a complete circle or oval and have an overlap / seal. Figure 9 and Figure 10 show that the belt const

58、ruction is such that the bending stiffness at the overlap sections, which are the two edge sections, is lower than the bending stiffness of the center of the belt.</p><p>　　CONVEYOR SUITABILITY</p>&l

59、t;p>　　None of the three individual belt conveyor concepts will be preferable / acceptable for all applications. Figure 11 can be used to distinguish between the areas of suitability accounting for capacity, lump size,

60、 and inclination angle.</p><p><b>　　Figure 11</b></p><p>　　Graph of areas of suitability at 1 m/s</p><p>　　Figure 11 already shows the capacity range for the different b

61、elt conveyor types. The capacity of closed conveyor systems depends on a number of parameters including:</p><p>　　the cross sectional area of the belt </p><p>　　the percentage of that area that

62、can be filled (maximum filling degree). The maximum volumetric filling degree is typically in the range of 50-60%. </p><p>　　the lump size of the bulk solid material (shown in Figure 11). The maximum lump si

63、ze is about one third of the pipe or pouch diameter. </p><p>　　weight limitations in terms of a maximum weight per meter of belt </p><p>　　the belt speed (shown in Figure 11) </p><p&g

64、t;　　Figure 12 shows the average volumetric capacity at 1 m/s as a function of the pipe or pouch diameter. In general a closed conveyor system requires a 50% wider belt compared to a belt used in a conventional open belt

65、conveyor system to achieve the same volumetric capacity. The increase in belting costs however is less, about 20% depending on the belt’s reinforcement. This rule is now being seriously tested with the introduction of mu

66、ch higher belt speeds, which has been made possible because of t</p><p><b>　　Figure 12</b></p><p>　　Capacity of closed conveyor systems at a belt speed of 1 m/s</p><p>　

67、　CONVEYOR LOADING AND UNLOADING PROCEDURES</p><p>　　Conventional belt and pipe conveyors are loaded and unloaded in exactly the same way; being opened for a conventional belt feed system from the tail pulley

68、 and again opening out at the head pulley for discharging.</p><p><b>　　Figure 13</b></p><p>　　Pipe belt feeding and closing</p><p><b>　　Figure 14</b></p&g

69、t;<p>　　Pipe Belt Opening and Discharging</p><p>　　The pouch belt however uses a much more restrictive type of loading arrangement but may have a similar discharge to the other systems. All the disadv

70、antages of a conventional loading point have been eliminated in the pouch belt where spillage and off center loading should not occur. However overloading now becomes a major concern and this problem is also carried thro

71、ugh to the pipe conveyor. It is essential that both the pouch and pipe conveyor have a controlled feeding point to ensure that no o</p><p><b>　　Figure 15</b></p><p>　　Pouch belt feed

72、ing</p><p><b>　　Figure 16</b></p><p>　　Pouch belt discharging: horizontal discharge</p><p>　　CONVEYOR GEOMETRY</p><p>　　Besides all the environmental benefi

73、ts, one of the most important advantages of closed belt conveyor systems is their ability to run around small radii curves. In conventional open belt conveyor systems the radius of a curve is primarily determined by the

74、belt tension in the curve. In horizontal curves the curve radius should be large enough to prevent, together with the application of banking angles, the belt from running off the idlers. In vertical curves the radius sho

75、uld be large enough to p</p><p>　　Closed belt conveyor systems have in general much smaller idler spacing than those used in open belt conveyor systems. The radius of a curve in a closed belt conveyor system

76、 is therefore primarily determined by the admissible belt stretch. Further, the radius of a curve should be large enough to maintain the belt’s typical cross section (a pipe should stay a pipe) and to stabilize the posit

77、ion of the belt in the idlers (rotation of the pipe in a pipe conveyor should be prevented). Belt running o</p><p><b>　　Figure 17</b></p><p>　　Typical radii of horizontal curves for

78、different belt conveyors</p><p>　　Figure 17 shows typical horizontal curve radii of closed belt conveyor systems supported by idlers. As can be seen in that figure the required radii are less than half or on

79、e third of the radii used in open belt conveyor systems. A pouch belt conveyor, like the Enerka-Becker System, is superior in this respect with typical horizontal curve radii that are only a fraction of the radii require

80、d for an open belt conveyor.</p><p><b>　　Figure 18</b></p><p>　　Typical bend station for a Pouch Conveyor</p><p><b>　　Figure 19</b></p><p>　　Det

81、ails of bend pulley</p><p>　　A further reduction of the radius of a horizontal curve for a pouch belt conveyor is even possible by the application of a pulley to support the belt instead of idlers. In that c

82、ase the radius of a horizontal curve can be less than one meter assuming that the belt is not fully loaded. Also see Figure 18 and Figure 19. For the determination of the required radius of a vertical curve of a closed b

83、elt conveyor system Figure 17 can be used as well except that the pouch conveyor EP or EBS belt line i</p><p><b>　　Figure 20</b></p><p>　　Pipe conveyor negotiating a 300m radius and

84、a 90deg curve.</p><p>　　For very small radii curves, buckling of the pouch of a reinforced pouch conveyor can hardly be prevented. The load carrying section of the reinforcement however, that is located next

85、 to the axial profiles, will never buckle. The tension carrying ability is therefore never affected. Experience has shown that also the pouch is not damaged because of buckling. It does however reduce the capacity. Very

86、small radii curves are therefore mostly applied in belt sections where the belt carries no load. </p><p>　　Buckling of a pipe conveyor however is not acceptable because it does not only seriously reduces its

87、 capacity but it may damage the load carrying member as well. The pipe conveyor belt must therefore have sufficient strength to withstand buckling when forming tight vertical and horizontal curves.</p><p>　　

88、Conveyor Structural Design</p><p>　　Considering that the structural design of all types of conveying systems will undergo the biggest revolution in the coming years, with a view to eliminating as much of the

89、 structure as possible. The pouch conveyor goes a long way in reducing the amount of steelwork required per ton of material conveyed and Figure 21 indicates how simple the construction can be made. The Enerka-Becker Syst

90、em is characterized by very low belt tensions due to the application of a unique multiple drive system. The l</p><p><b>　　Figure 21</b></p><p>　　Typical cross section of an EBS</p

91、><p><b>　　Figure 22</b></p><p>　　Typical Enerka-Becker Layout</p><p>　　ENVIRONMENTAL IMPACT</p><p>　　When one considers open and closed conveyors the following

92、 environment advantages are present on the closed conveyors:</p><p>　　Ambient dust can not develop during transportation since the bulk solid material is locked-up in the closed belt. Ambient dust developmen

93、t can be a significant problem when transporting fine granular materials such as grain and cement.</p><p>　　Governmental regulations sometimes prescribe the application of dust-free conveyor systems or subsi

94、dize their installation.</p><p>　　If the return strand of the conveyor belt is also closed, then no bulk solid material can build up underneath the conveyor. This can be a major problem with conventional, tr

95、oughed belt conveyor systems when conveying sticky materials such as loam. At the discharge point of a conventional belt conveyor this material will partly stick to the belt causing build-up on the return rollers and on

96、other mechanical parts. This can never be avoided completely, even not when belt scrapers are used. Moreove</p><p>　　Closed conveyor systems are able to make vertical and horizontal curves with smaller radii

97、 then open belt conveyors. This is a great advantage when there is little space to place a conveyor system.</p><p>　　Closed conveyor systems allows for steeper inclination angles than conventional, troughed

98、(non-profiled) conveyor belts. The main reason for this is that the belt locks up the bulk material causing a higher internal pressure in the bulk material. This increases the internal friction of the material meaning th

99、at a steeper inclination angle than normal is required to start material run back. A non-profiled belt has a maximum inclination angle of about 17 degrees. Profiled belts, such as chevron or</p><p>　　Because

100、 of the ability to run through small radii curves, closed conveyor systems We consider that a transfer point should only be there for one reason, “We have no alternative”. A transfer point is the biggest cause of failure

101、, damage, power loss, labor consumption and high environmental impact. A change in direction need not mean a transfer point.</p><p>　　CONCLUSION</p><p>　　ACKNOWLEDGEMENT</p><p>　　Th

102、e author is grateful to Mr. P. Staples, managing director of Conveyor Knowledge and Information Technology cc (CKIT) for his kind assistance in writing this paper.</p><p>　　REFERENCES</p><p>　　[