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編號
無錫太湖學院
畢業(yè)設計(論文)
相關資料
題目: 工業(yè)窯爐的設計(輸送裝置)
信機 系 機械工程及自動化 專業(yè)
學 號: 0923220
學生姓名: 李 歡
指導教師: 徐偉明(職稱: 教 授 )
(職稱: )
2013年5月25日
目 錄
一、畢業(yè)設計(論文)開題報告
二、畢業(yè)設計(論文)外文資料翻譯及原文
三、學生“畢業(yè)論文(論文)計劃、進度、檢查及落實表”
四、實習鑒定表
無錫太湖學院
畢業(yè)設計(論文)
開題報告
題目: 工業(yè)窯爐的設計(輸送裝置)
信機系 機械工程及自動化 專業(yè)
學 號: 0923220
學生姓名: 李 歡
指導教師: 徐偉明(職稱: 教 授 )
(職稱: )
2012年11月20日
課題來源
本課題來源于導師布置的任務導老師
科學依據(包括課題的科學意義;國內外研究概況、水平和發(fā)展趨勢;應用前景等)
輸送裝置的設計是機械工程及其自動化專業(yè)所包含的一個較為基礎的內容,選擇輸送裝置方向的畢業(yè)設計題目完全符合本專業(yè)的要求,從應用性方面來說,輸送裝置又是很多機器所必不可少的一個部分。有效保證輸送裝置的功率及穩(wěn)定性能夠達到設計的要求,具有很好的發(fā)展前途和應用前景。
研究內容
1、 選擇電動機,計算傳動裝置的運動和動力參數(shù);
2、 擬定、分析傳動裝置的運動和動力參數(shù);
3、 進行傳動件的設計計算,校核軸、軸承、聯(lián)軸器、鍵等;
4、 繪制減速器裝配圖及典型零件圖(圖紙數(shù)達到3張或以上);
5、 完成設計說明一份,分析明晰,計算正確,闡述清楚。適合的生產加工工 藝
擬采取的研究方法、技術路線、實驗方案及可行性分析
首先確定整體設計方案,由公式的演算得到電動機的動力和運動分析,在以此推算相配的傳動件,軸系零部件的尺寸規(guī)格。綜上計算可以得到相關尺寸,再根據力學性能對所得零部件尺寸進行校驗從而驗證整體方案是否可行。
研究計劃及預期成果
研究計劃:
2012年11月 布置任務。
2013年1月 對課題研究方向進行學習
2013年2月~3月 擬定方案,提出專機總體方案,供討論
2013年4月5日~10日 確定方案,專機總體布置
11日~20日 整機設計、部件設計
21日~30日 改進并完成設計
2013年5月1日~10日 撰寫設計說明書
11日~15日 總結
預期成果:圖紙、設計說明書
特色或創(chuàng)新之處
帶式輸送機本身便具有價格便宜,標準化程度高特點,使成本大幅降低。高速級齒輪常布置在遠離扭矩輸入端的一邊,以減小因彎曲變形所引起的載荷沿齒寬分布不均現(xiàn)象。
已具備的條件和尚需解決的問題
與指導老師的溝通中,對自己所做課題有了整體的認識,清晰了思路。指導老師提供了論文指導,從而使自己明確了每一步的方向。因第一次繪制復雜的裝配圖,所以在繪圖方面還有待提高。
指導教師意見
同意作為本專業(yè)學生畢業(yè)設計課題,其難度和工作量均合適。
指導教師簽名:
年 月 日
教研室(學科組、研究所)意見
教研室主任簽名:
年 月 日
系意見
主管領導簽名:
年 月 日
英文原文
Esign of Speed Belt Conveyors
G. Lodewijks, The Netherlands.
This paper discusses aspects of high-speed belt conveyor design. The capacity of a belt conveyor is determined by the belt speed given a belt width and troughing angle. Belt speed selection however is limited by practical considerations, which are discussed in this paper. The belt speed also affects the performance of the conveyor belt, as for example its energy consumption and the stability of it's running behavior. A method is discussed to evaluate the energy consumption of conveyor belts by using the loss factor of transport. With variation of the belt speed the safety factor requirements vary, which will affect the required belt strength. A new method to account for the effect of the belt speed on the safety factor is presented. Finally, the impact of the belt speed on component selection and on the design of transfer stations is discussed.
Belt machine by conveyor belt continuous or intermittent motion to transport all kinds of different things ,Can transport all kinds of bulk materials, but also transport a variety of cardboard boxes, packaging bags, weight of single pieces of small goods, a wide range of uses . Belt conveyor belt material: rubber, silicone, PVC, PU and other materials, in addition to ordinary material conveying, but also to meet the transmission oil resistant, corrosion resistance, antistatic and other special requirements for material. Belt conveyor structure: groove belt machine, flat belt conveyor, climbing belt machine, turning machines and other forms belt, conveyor belt can also be created to enhance the tailgate, skirts and other accessories, can meet a variety of technological requirements.The belt conveyor drive: deceleration motor drive, electric drive roller.Belt conveyor mode: frequency control, stepless transmission.The belt rack material: carbon steel, stainless steel, aluminum profile.Scope of application: light industry, electronics, food, chemical, wood, etc..Belt machine equipment characteristics: belt conveyor is stable, the material and the conveyor belt there is no relative motion, to avoid damage to the carrier material. Low noise, suitable for quiet work environment requirements. Simple structure, easy maintenance. Low energy consumption, low use cost.
Conveyor is a common don't have flexible traction component continuous conveying machinery, also called continuous conveyor.It is a material handling equipment, it with handling ability strong, persistent, direction, flexible, and other advantages in industrial production in large being applied. Although many types of belt conveyor, but its working principle is basic similar, most are driving draught device and drive transmission container transport materials. Conveyor can undertake level, the tilt and vertical conveyor, also can make the space transport routes, transmission lines is usually fixed, is a modern production and logistics transport indispensable important mechanical equipment. It has transmission capacity is strong, long distance transportation etc.
With the development of industry, conveyor also obtained fast development, conveyor products have been also gradually improved. With the emergence of the power equipment of similar principle is applied, conveyor continuing into the 19th century, britons use basketwork, wire rope for traction belt conveyor. The principle of belt conveyor, when applied in the 17th century also recorded conveyor, in 1880 German company developed driven by steam belt conveyor. Then the British and German and launched inertial conveyor, if the conveyor belt, the application of the principle, creating a tilt of the belt conveyor, belt, traction with chains. All sorts of conveyor during this time arise conveyor, based on human, hydraulic power drive such. All the structures conveyor successively appeared. In 1887 americans produced the screw conveyor, make enterprise internal, between enterprise and inter-city transportation possible. The development history of belt conveyor, they very ancient instead of the original motive for conveyor provide driving force. Ancient people began to use water overturned and high TongChe conveyor, in turn after the water conservancy project's belt conveyor begin in power. Quick-tempered exalts
According to the mode of operation conveying machinery can be divided into: 1: belt conveyor 2: screw conveyor 3: dou pattern lift machine
The future of large scale, will toward belt use scope, energy consumption, low pollution less, material automatically grading, etc.
Past research has shown the economical feasibility of using narrower, faster running conveyor belts versus wider, slower running belts for long overland belt conveyor systems. See for example [I]-[5]. Today, conveyor belts running at speeds around 8 m/s are no exceptions. However, velocities over 10 m/s up to 20 m/s are technically (dynamically) feasible and may also be economically feasible. In this paper belt speeds between the 10 and 20 m/s are classified as high. Belt speeds below the 10 m/s are classified as low.
Using high belt speeds should never be a goal in itself. If using high belt speeds is not economically beneficial or if a safe and reliable operation is not ensured at a high belt speed then a lower belt speed should be selected.
Selection of the belt speed is part of the total design process. The optimum belt conveyor design is determined by static or steady state design methods. In these methods the belt is assumed to be a rigid, inelastic body. This enables quantification of the steady-state operation of the belt conveyor and determination of the size of conveyor components. The specification of the steady-state operation includes a quantification of the steady-state running belt tensions and power consumption for all material loading and relevant ambient conditions. It should be realized that finding the optimum design is not a one-time effort but an iterative process [6].
Design fine-tuning, determination of the optimum starting and stopping procedures, including determination of the required control algorithms, and determination of the settings and sizes of conveyor components such as drives, brakes and flywheels, are determined by dynamic design methods. In these design methods, also referred to as dynamic analyses, the belt is assumed to be a three-dimensional (visco-) elastic body. A three dimensional wave theory should be used to study time dependent transmission of large local force and displacement disturbances along the belt [7]. In this theory the belt is divided into a series of finite elements. The finite elements incorporate (visco-) elastic springs and masses. The constitutive characteristics of the finite elements must represent the rheological characteristics of the belt. Dynamic analysis produces the belt tension and power consumption during non-stationary operation, like starting and stopping, of the belt conveyor.
This paper discusses the design of high belt-speed conveyors, in particular the impact of using high belt speeds on the performance of the conveyor belt in terms of energy consumption and safety factor requirements. Using high belt speeds also requires high reliability of conveyor components such as idlers to achieve an acceptable component life. Another important aspect of high-speed belt conveyor design is the design of efficient feeding and discharge arrangements. These aspects will be discussed briefly.
Many methods of analyzing a belt’s physical behavior as a rheological spring have been studied and various techniques have been used. An appropriate model needs to address:
1. Elastic modulus of the belt longitudinal tensile member
2. Resistances to motion which are velocity dependent (i.e. idlers)
3. Viscoelastic losses due to rubber-idler indentation
4. Apparent belt modulus changes due to belt sag between idlers
Since the mathematics necessary to solve these dynamic problems are very complex, it is not the goal of this presentation to detail the theoretical basis of dynamic analysis. Rather, the purpose is to stress that as belt lengths increase and as horizontal curves and distributed power becomes more common, the importance of dynamic analysis taking belt elasticity into account is vital to properly develop control algorithms during both stopping and starting.
Using the 8.5 km conveyor in Figure 23 as an example, two simulations of starting were performed to compare control algorithms. With a 2x1000 kW drive installed at the head end, a 2x1000 kW drive at a midpoint carry side location and a 1x1000kW drive at the tail, extreme care must be taken to insure proper coordination of all drives is maintained.
Figure 27 illustrates a 90 second start with very poor coordination and severe oscillations in torque with corresponding oscillations in velocity and belt tensions. The T1/T2 slip ratio indicates drive slip could occur. Figure 28 shows the corresponding charts from a relatively good 180 second start coordinated to safely and
smoothly accelerate the conveyor.
Figure 27-120 Sec Poor Start
BELTSPEED
BELT SPEED SELECTION
The lowest overall belt conveyor cost occur in the range of belt widths of 0.6 to 1.0 m [2]. The required conveying capacity can be reached by selection of a belt width in this range and selecting whatever belt speed is required to achieve the required flow rate. Figure 1 shows an example of combinations of belt speed and belt width to achieve Specific conveyor capacities. In this example it is assumed that the bulk density is 850 kg/m3 (coal) and that the trough angle and the surcharge angle are 35' and 20' respectively.
Figure 1: Belt width versus belt speed for different capacities.
Belt speed selection is however limited by practical considerations. A first aspect is the troughability of the belt. In Figure 1 there is no relation with the required belt strength (rating), which partly depends on the conveyor length and elevation. The combination of belt width and strength must be chosen such that good troughability of the belt is ensured. If the troughability is not sufficient then the belt will not track properly. This will result in unstable running behavior of the belt, in particular at high belt speeds, which is not acceptable. Normally, belt manufacturers expect a sufficiently straight run if approximately 40% of the belt width when running empty, makes contact with the carrying idlers. Approximately 10% should make tangential contact with the center idler roll.
A second aspect is the speed of the air relative to the speed of the bulk solid material on the belt (relative airspeed). If the relative airspeed exceeds certain limits then dust will develop. This is in particular a potential problem in mine shafts where a downward airflow is maintained for ventilation purposes. The limit in relative airspeed depends on ambient conditions and bulk material characteristics.
A third aspect is the noise generated by the belt conveyor system. Noise levels generally increase with increasing belt speed. In residential areas noise levels are restricted to for example 65 dB. Although noise levels are greatly affected by the design of the conveyor support structure and conveyor covers, this may be a limiting factor in selecting the belt speed.
BELT SPEED VARIATION
The energy consumption of belt conveyor systems varies with variation of the belt speed, as will be shown in Section 3. The belt velocity can be adjusted with bulk material flow supplied at the loading point to save energy. If the belt is operating at full tonnage then it should run at the high (design) belt speed. The belt speed can be adjusted (decreased) to the actual material (volume) flow supplied at the loading point. This will maintain a constant filling of the belt trough and a constant bulk material load on the belt. A constant filling of the belt trough yields an optimum loading-ratio, and lower energy consumption per unit of conveyed material may be expected. The reduction in energy consumption will be at least 10% for systems where the belt speed is varied compared to systems where the belt speed is kept constant [8].
Varying the belt speed with supplied bulk material flow has the following advantages:
Less belt wear at the loading areas
Lower noise emission
Improved operating behavior as a result of better belt alignment and the avoidance of belt lifting in concave curve by reducing belt tensions
Drawbacks include:
Investment cost for controllability of the drive and brake systems
Variation of discharge parabola with belt speed variation
Control system required for controlling individual conveyors in a conveyor system
Constant high belt pre-tension
Constant high bulk material load on the idler rolls
An analysis should be made of the expected energy savings to determine whether it is worth the effort of installing a more expensive, more complex conveyor system.
ENERGY CONSUMPTION
Clients may request a specification of the energy consumption of a conveyor system, for example quantified in terms of maximum kW-hr/ton/km, to transport the bulk solid material at the design specifications over the projected route. For long overland systems, the energy consumption is mainly determined by the work done to overcome the indentation rolling resistance [9]. This is the resistance that the belt experiences due to the visco-elastic (time delayed) response of the rubber belt cover to the indentation of the idler roll. For in-plant belt conveyors, work done to overcome side resistances that occur mainly in the loading area also affects the energy consumption. Side resistances include the resistance due to friction on the side walls of the chute and resistance that occurs due to acceleration of the material at the loading point.
The required drive power of a belt conveyor is determined by the sum of the total frictional resistances and the total material lift. The frictional resistances include hysteresis losses, which can be considered as viscous (velocity dependent) friction components. It does not suffice to look just at the maximum required drive power to evaluate whether or not the energy consumption of a conveyor system is reasonable. The best method to compare the energy consumption of different transport systems is to compare their transport efficiencies.
TRANSPORT EFFICIENCY
There are a number of methods to compare transport efficiencies. The first and most widely applied method is to compare equivalent friction factors such as the DIN f factor. An advantage of using an equivalent friction factor is that it can also be determined for an empty belt. A drawback of using an equivalent friction factor is that it is not a 'pure' efficiency number. It takes into account the mass of the belt, reduced mass of the rollers and the mass of the transported material. In a pure efficiency number, only the mass of the transported material is taken into account.
The second method is to compare transportation cost, either in kW-hr/ton/km or in $/ton/km. The advantage of using the transportation cost is that this number is widely used for management purposes. The disadvantage of using the transportation cost is that it does not directly reflect the efficiency of a system.
The third and most "pure" method is to compare the loss factor of transport [10]. The loss factor of transport is the ratio between the drive power required to overcome frictional losses (neglecting drive efficiency and power loss/gain required to raise/lower the bulk material) and the transport work. The transport work is defined as the multiplication of the total transported quantity of bulk material and the average transport velocity. The advantage of using loss factors of transport is that they can be compared to loss factors of transport of other means of transport, like trucks and trains. The disadvantage is that the loss factor of transport depends on the transported quantity of material, which implies that it can not be determined for an empty belt conveyor.
The following are loss factors of transport for a number of transport systems to illustrate the concept:
Continuous transport:
Slurry transport around 0.01
Belt conveyors between 0.01 and 0.1
Vibratory feeders between 0.1 and 1
Pneumatic conveyors around 1 0
Discontinuous transport:
Ship between 0.001 and 0.01
Train around 0.01
Truck between 0.05 and 0.1
INDENTATION ROLLING RESISTANCE
For long overland systems, the energy consumption is mainly determined by the work done to overcome the indentation rolling resistance. Idler rolls are made of a relatively hard material like steel or aluminum whereas conveyor belt covers are made of much softer materials like rubber or PVC. The rolls therefore indent the belt's bottom-cover when the belt moves over the idler rolls, due to the weight of the belt and bulk material on the belt. The recovery of the compressed parts of the belt's bottom cover will take some time due to its visco-elastic (time dependent) properties. The time delay in the recovery of the belt's bottom cover results in an asymmetrical stress distribution between the belt and the rolls, see Figure 2. This yields a resultant resistance force called the indentation rolling resistance force. The magnitude of this force depends on the visco-elastic properties of the cover material, the radius of the idler roll, the vertical force due to the weight of the belt and the bulk solid material, and the radius of curvature of the belt in curves in the vertical plane.
Figure 2: Asymmetric stress distribution between belt and roll [7].
It is important to know how the indentation rolling resistance depends on the belt velocity to enable selection of a proper belt velocity, [11].
Figure 3: Loss factor (tanb) of typical cove