ABSTRACT Belt Conveyor Systems, referred to as BCS, have been used worldwide for conveying passengers, general cargo and bulk cargo for about 250 years. BCS plays an important role in continuous bulk material transport in the mining industry, on bulk terminals, in cement plants, power plants, chemical production, and so on. Compared to other transportation modes often used for the transportation of bulk solid materials, such as trains or trucks, BCS are the most encouraged means to transport large volumes rapidly and efficiently through production processes in areas where roads and railway infrastructures do not exist or are under-developed. BCS transports work materials from one point to another with less consumption of energy and man power. For that, BCS has to work continuously without any stop even when there is no load on the conveyor belt. This traditional Conveyor would consume more useful energy and result in equipment fatigue in less time unnecessary. To avoid this demerit of BCS we would like to introduce “Energy saving Conveyor System” that not only saves energy but also increases the lifespan of the conveyor automatically. The productivity level in an advanced manufacturing environment can be improved by proper design of mechanism at the initial stage in the manufacturing system. By using IR load sensors and smart techniques we can control functioning of Conveyor system efficiently. Not only that but the approach of modelbased design and simulation was used to achieve optimal efficiency of conveyor belt during its operation. Working parameters that can determine the measurable performance of conveyors were studied and presented in a classical model. Keywords : Belt Conveyor System ; Conveyor ; Efficiency ; IR-sensors ; transport ; Modeling ; Simulation ; CONTENTS TITLE 0 - INTRODUCTION PAGE NO 1 0.1- BRIEF CLASSIFICATION OF CONVEYORS 4 0.2- LITERATURE REVIEW 4 0.3- OBJECTIVES OF OUR PROJECTS 4 1 – CONSTRUCTION 5 2 – THE USE OF IR SENSORS 7 2.1 – TYPES OF IR SENSOR 7 2.2 - IR SENSOR REQUIRED FOR ENERGY SAVING CONVEYOR 2.3-WORKING PRINCIPLE OF IR SENSOR 8 10 3 – DESIGN AND SIMULATION 14 4 – WORKING PRINCIPLE 17 5 – DESIGN CONSIDERATION AND CALCULATION 6 – MATERIALS AND COMPONENETS REQUIRED 7– ADVANTAGES AND DISADVANTAGES 23 24 7.1 – ADVANTAGES 24 7.2 – DISADVANTAGES 24 8 - CONCLUSION 26 9 - FUTURE SCOPE 27 10-REFERENCE 28 LIST OF FIGURES TITLE PAGE NO Figure 1 -Conventional troughed belt conveyor 1 Figure-2 – Construction of Conveyor belt 5 Figure 3 -Belt conveyor Assembly 6 Figure 4a -IR sensor Circuit 7 Figure 4b- IR Sensor Circuit 10 Figure 5- Schematic representation of sensor 12 Figure 6- Full Assembly without sensor 14 Figure 7-Rope belt 14 Figure 8- Clamp for the Roller 16 Figure 9- base frame 16 Figure 10 - Roller 17 Figure 11-Conveyer Trainer Board 19 1 0. INTRODUCTION Primitive conveyor belts were used since the 19th century. In 1892, Thomas Robins began a series of inventions which led to the development of a conveyor belt used for carrying coal, ores and other products. In 1901, Sandvik invented and started the production of steel conveyor belts. In 1905 Richard Sutcliffe invented the first conveyor belts for use in coal mines which revolutionized the mining industry. In 1913, Henry Ford introduced conveyor-belt assembly lines at Ford Motor Company's Highland Park, Michigan factory. In 1972, the French society REI created in New Caledonia the longest straight-belt conveyor in the world, at a length of 13.8 km. Hyacynthe Marcel Bocchetti was the concept designer. In 1957, the B. F. Goodrich Company patented a Möbius strip conveyor belt, that it went on to produce as the "Turnover Conveyor Belt System". Incorporating a half-twist, it had the advantage over conventional belts Figure 1-Conventional troughed belt conveyor 2 of a longer life because it could expose all of its surface area to wear and tear. Fig. 1.1 shows a conventional troughed belt conveyor. Conveyors are durable and reliable components used in automated distribution and warehousing, as well as manufacturing and production facilities. In combination with computer-controlled pallet handling equipment this allows for more efficient retail, wholesale, and manufacturing distribution. It is considered a labor-saving system that allows large volumes to move rapidly through a process, allowing companies to ship or receive higher volumes with smaller storage space and with less labor expense. Belt conveyors are the most commonly used powered conveyors because they are the most versatile and the least expensive. Products are conveyed directly on the belt so both regular and irregular shaped objects, large or small, light and heavy, can be transported successfully. Belt conveyors are also manufactured with curved sections which use tapered rollers and curved belting to convey products around a corner. These conveyor systems are commonly used in postal sorting offices and airport baggage handling systems. Belt conveyors are generally fairly similar in construction consisting of a metal frame with rollers at either end of a flat metal bed. Rubber conveyor belts are commonly used to convey items with irregular bottom surfaces, small items that would fall in between rollers (e.g. a sushi conveyor bar), or bags of product that would sag between rollers. The belt is looped around each of the rollers and when one of the rollers is 3 powered (by an electrical motor) the belting slides across the solid metal frame bed, moving the product. In heavy use applications the beds which the belting is pulled over are replaced with rollers. The rollers allow weight to be conveyed as they reduce the amount of friction generated from the heavier loading on the belting. The exception to the standard belt conveyor construction is the Sandwich Belt conveyor. The Sandwich Belt conveyor uses two conveyor belts, instead of one. These two conventional conveyor belts are positioned face to face, to firmly contain the items being carried in a "sandwich-like" hold. 4 0.1. BRIEF CLASSIFICATION OF CONVEYORS A wide variety of related conveying machines are available, different as regards principle of operation, means and direction of conveyance, including vibrating 1. Screw conveyors 2. Pneumatic conveyors 3. The moving floor system, which uses reciprocating slats to move cargo, and 4. Roller conveyor system, which uses a series of powered rollers to convey boxes or pallets. 0.2. LITERATURE REVIEW After verifying all the research works and journals similar to our project, we were able to guide our project to achieve all the problems they could not solve through introducing sensors and variable speed mechanism into conveyors as a result of which we will be able to save more 20% energy. 0.3.OBJECTIVES OF OUR PROJECT A. Determining of all the equipments to be bought for making the prototype B. CAD designing and analysis of the project through CATIA and ANSYS C. Making of prototype model D. Examining the prototype. 5 1. CONSTRUCTION One typical layout of BCS is the conventional troughed belt conveyor (Figure 1.1 and Figure 1.2). The length of a belt in such a system may vary from 10 m to 20,000 m. The velocity can reach up to 9 m/s and the width can vary from about 0.3 m to 3.2 m. Today’s the highest capable belt conveyors carry up to 40,000 tons/hour of lignite at the RWE lignite mines in Germany (Küsel, 2004). A troughed belt conveyor normally consists of an endless rubber belt reinforced in the warp or longitudinal direction by a polyester or nylon fabric or steel cords. The belt is supported along its length by rotating idler rolls and suspended between pulleys at either end. A drive pulley is powered to rotate the belt and Figure-2 – Construction of Conveyor belt move the materials on the belt forward. A tensioning device, also called a take-up, applies pre-tension on the belt to limit belt sag and to allow 6 drive power transmission (Figure 1.3). The belt can be stopped by means of an operational stop utilizing the motors or an emergency stop utilizing brakes if the BCS has brakes. Figure 1.3 shows the principle assembly of the system of a belt conveyor. The configuration and applied components of the system can vary based Figure 3-Belt conveyor Assembly on design requirements. Taking the assembled elements into account, a belt conveyor can be considered as a system that consists of a number of components. Such a system is as reliable as the combined reliability of its components. The malfunction of one of the components may lead to expensive downtime if it causes a total shutdown of the system. The downtime of one of the conveyors in a sequential conveying system may result in a stop of the production process. Increasing the reliability of the components of a BCS, and therefore of the BCS itself, is a direct way to minimize system downtime and to reduce the cost of downtime for the companies using belt conveyors. Since a BCS cannot be designed to be 100% reliable and the reliability of BCS components decreases with 7 aging and when wear occurs, proper maintenance techniques are required to maintain the reliability of the various components and the system. 2. THE USE OF IR-SENSORS An infrared sensor is an electronic device, that emits in order to sense some aspects of the surroundings. An IR sensor can measure the heat of an object as well as detects the motion. These types of sensors measure only infrared radiation, rather than emitting it that is called a passive IR sensor. Usually, in the infrared spectrum, all the objects radiate some form of thermal radiation. These types of radiations are invisible to our eyes, that can be detected by an infrared sensor. The emitter is simply an IR LED (Light Emitting Diode) and the detector is simply an IR photodiode that is sensitive to IR light of the same wavelength as that emitted by the IR LED. When IR light falls on the photodiode, the resistances and the output voltages will change in proportion to the magnitude of the IR light received. 2.1. TYPES OF IR SENSORS: Active IR Sensors: Active IR Sensors are the type of IR Sensors that employs an IR source & IR detector (emitter & receiver). They operate by transmitting energy from either a light emitting diode (LED) or a laser diode. A phototransistor is used as an active IR detector. In these types of IR sensors, the LED or laser diode illuminates the target, and the reflected energy is focused onto 8 a detector. Photoelectric cells, Photodiode or phototransistors are generally used as detectors. The measured data is then processed using various signal-processing algorithms to extract the desired information. Active IR detectors provide count, presence, speed, and occupancy data. Passive IR Sensors: These are basically IR detectors; they don’t use any IR source. These form the major class of IR sensors/detectors. A passive infrared system detects energy emitted by objects in the field of view and may use signal-processing algorithms to extract the desired information. It does not emit any energy of its own for the purposes of detection. Passive infrared systems can detect presence, occupancy, and count. 2.2-IR SENSOR REQUIRED FOR ENERGY SAVING CONVEYOR Obstacle Sensing Circuit or IR Sensor Circuit A typical IR sensing circuit is shown below. It consists of an IR LED, a photodiode, a potentiometer, an IC Operational amplifier and an LED. IR LED emits infrared light. The Photodiode detects the infrared light. An IC Op – Amp is used as a voltage comparator. The potentiometer is used to calibrate the output of the sensor according to the requirement. When the light emitted by the IR LED is incident on the photodiode after hitting an object, the resistance of the photodiode falls down from a huge 9 value. One of the inputs of the op – amp is at threshold value set by the potentiometer. The other input to the op-amp is from the photodiode’s series resistor. When the incident radiation is more on the photodiode, the voltage drop across the series resistor will be high. In the IC, both the threshold voltage and the voltage across the series resistor are compared. If the voltage across the resistor series to photodiode is greater than that of the threshold voltage, the output of the IC Op – Amp is high. As the output of the IC is connected to an LED, it lightens up. Therefore, if we adjust the threshold voltage according to the load then at a specific minimum load, conveyor starts moving until the load is unloaded and once unloaded it stops automatically. Basically, we see a part of this in conveyors of escalator but those sensors are single starter that is if it starts, even after unloading it does not stop at the moment and takes time to stop and load detection is for a certain range around 5- 15 m maximum. But if we are looking to incorporate it within a standard industrial conveyor which spreads over kilometres then those sensors must be fitted at regular intervals and must be powerful enough and along with it there should other sensors to monitor there functioning. And to advantage if we properly design it through simulation to make it variable speed mechanism that is different speeds for varied loads then a massive amount of power consumption can be compromised. 10 The threshold voltage can be adjusted by adjusting the potentiometer depending on the environmental conditions. The positioning of the IR LED and the IR Receiver is an important factor. When the IR LED is held directly in front of the IR receiver, this Figure 4a -IR sensor Circuit setup is called Direct Incidence. In this case, almost the entire radiation from the IR LED will fall on the IR receiver. Hence there is a line of sight communication between the infrared transmitter and the receiver. If an object falls in this line, it obstructs the radiation from reaching the receiver either by reflecting the radiation or absorbing the radiation. 2.3-WORKING PRINCIPLE OF IR SENSOR An infrared sensor circuit is one of the basic and popular sensor module in an electronic device. This sensor is analogous to human’s visionary senses, which can be used to detect obstacles and it is one of the common 11 applications in real-time. This circuit comprises of the following components LM358 IC 2 IR transmitter and receiver pair Resistors of the range of kilo-ohms. Variable resistors. LED (Light Emitting Diode). Figure 4(b)- IR Sensor Circuit In this project, the transmitter section includes an IR sensor, which transmits continuous IR rays to be received by an IR receiver module. An IR output terminal of the receiver varies depending upon its receiving of IR rays. Since this variation cannot be analyzed as such, therefore this output can be fed to a comparator circuit. Here an operational amplifier (op-amp) of LM 339 is used as comparator circuit. When the IR receiver does not receive a signal, the potential at the inverting input goes higher than that non-inverting input of the comparator IC (LM339). Thus, the output of the comparator goes low, but the LED does not glow. When the IR receiver module receives signal to the potential at the inverting input goes low. Thus, the output of the comparator (LM 339) goes high and the LED starts glowing. Resistor 12 R1 (100), R2 (10k) and R3 (330) are used to ensure that minimum 10 mA current passes through the IR LED Devices like Photodiode and normal LEDs respectively. Resistor VR2 (preset=5k) is used to adjust the output terminals. Resistor VR1 (preset=10k) is used to set the sensitivity of the circuit Diagram. Read more about IR sensors. 13 Figure 5- Schematic representation of sensor DC motor that operated at 12(v)/24(v) DC supply. The voltage depends upon speed require for the process. This conventional method of conveyor control is further mobilized by use of dimmers. They were better option in the case of on off control they can be operated in full load condition also. But the main problem with them is stoppage of conveyors. the pneumatic stoppers were used which did not stop the belts completely but use to stop materials on it. This leads to wear and tear of the belts as well as the product also the rejection ratio is increased. Computerized conveyor belt system issued. In this the control of these belts is achieved by the use of the pc interface and embedded system based. These lead to better option of conveyor control in today’s industrial environment. It is very difficult for those to maintain them at 14 constant or through variable speeds. Recently single shop conveyor belt systems are modified to become multiple type i.e. instead of single conveyor multiple conveyors are used in series, parallel and speed is controlled using remote monitoring. Also, the recent trend is3 emerging towards controlling the speed of these conveyors by the use of computer technology. Conveyors are used in a broad range of industries and applications to move packaged goods, assemblies, process byproducts, or any material from one place to another. A process designer will typically look for opportunities to use the force of gravity to accomplish product movement. Electric motors are commonly used when gravity cannot be employed or when the speed of a gravitational fall needs to be controlled. Airports, mines, cement plants, distribution facilities, assembly, and food processing plants all utilize conveyors. Conveyors are typically constant torque loads, meaning the required torque to drive a conveyor is independent of speed. A fixed amount of torque is also required to overcome the frictional, or machine drag, portion of the total load. Conveyors can have nominal amounts of friction and machine inertia for which to compensate. Material flowing over the belt may be weighed in transit using a belt weigher. 15 3. DESIGN AND SIMULATION Figure 6-Full Assembly without sensor Figure 7-Rope belt 16 Figure 8-Clamp for the Roller Figure 9-base frame 17 Figure 10 - Roller 4. WORKING PRINCIPLE The use of IR-sensor enables the conveyor mechanism to detect the load on the conveyor belt. When a load rests on the conveyor belt IR sensor senses and sends the signal to processing unit. Processing units activates the driving wheel of the conveyor, the conveyor transports the materials, and stops when there is no load on the belt. Variable Speed Mechanism – Different load conditions will have different reflectivity for IR rays. Depending on the conditions of load carrying capacity, threshold voltage at the potentiometer are adjusted though computer aided control. In other words, we can say, heavy loads have higher triggering voltages hence the speed of conveyors will be faster for those and small loads will have 18 lesser speed of conveyor. Hence continuous moving conveyor is now a variable speed-controlled conveyor achieved through IR sensors. Problem of High Starting Torque for the electric drive motor that drives the conveyor is also solved in this process by incorporating AC drives coupled with IR sensors. Conveyors with a very high starting torque have the potential to damage both the mechanical equipment and the power supply. On long conveyors in particular, the loads can be very high as there is more material on the belt, with higher starting torque and more current required. Soft starters can be used to reduce the starting current, but they also reduce the torque. If the conveyor is fully loaded at start-up, it may not start at all if the torque is insufficient. The AC drive offers high starting torque combined with low starting current, eliminating current peaks and voltage fluctuations on the network. In addition, power factor is close to unity at all times. With a more stable network, all electrical equipment on site will run more reliably, increasing productivity and reducing the need for maintenance. Smooth starting with accurate torque also minimizes belt stretching and slippage. On belts that are already stretched, the AC drive minimizes the risk of slippage. 19 Figure 11-Conveyer Trainer Board 20 5. DESIGN CONSIDERATIONS AND CALCULATION Li = (mass of idlers – mi)/ (spacing between idlers-l) Lc = cc/v Notations and specific values Tb= belt tension Tp= tension in pulley Fx= friction coefficient = 0.02 Fy= run factor of conveyor=0.014 L= length of conveyor(mm) Li= idler load(kg/m) Lb=load effect of belt (kg/m) =17kg Lc=load of conveyor material (kg/m) H= conveyor height(m)=20mm Pp= power required by drive pulley(kw) Pm= power required to drive the electric motor v=speed of conveyor belt(m/s) =2.4m/s A=conveyor belt acceleration(m/secs)2 Bf= belt fracture strength I= spacing between idler=240mm D=diameter of driving pulley=0.62 T=ambient temperature N=number of revolutions per minute=75 rev/min g= acceleration due to gravity=9.8 m/s2 21 δ=angle of inclination of conveyor (in degrees) =6 Tt=operating time=12s Sk=start up coefficient Cc= capacity of conveyor=400kg/sec Cr=factor responsible for friction to occur Mi= mass of idler 1. Li= mi /I =20/1.4=14285.71 kg/m 2. Lc=Cc/v =400/2.4=166.66 kg/m 3. Tb= 1.37=Flg(2Li+2Lb+Lc) cosδ+HgLc= 1.37*0.02*240*10-3*9.81[(2*14285.71) +(2*17) +166.66] + (20*10-3*9.81*166.66) =1878.633N 4. Pp= Tb*v /1000 kw = 1878.633*2.4/1000=4.508 kw 5. Pm= Pp/ Df = 4.508 /0.9 = 5.0088 kw 6. Tt = 60 A = 60* 0.136=8.161 7. V= Ꙥ*D*N /60 m/s =Ꙥ*0.62*75 /60 = 2.435 m/s 22 8. Hp = (Pp+Pm) *1.05 kw = (4.508 + 5.0088) *1.05 kw = 9.9926 Kw 9. Tp = Tb + Sk= 1878.633*1.5 = 2817. 9495 10. A (Tp – Tb)/ L (2Li + 2Lb+ Lc = 939.316/ 6985.2992= 0.136 m/s2 23 6. COMPONENT USED AND FINAL COST NAME PRICE NO. COST CONVEYOR CONTROLLER 3500 1 3500 RELAY MODULE 600 1 600 MOTOR 400 1 400 BATTERY 800 1 800 ROLLER SETUP AND BELT 3000 1 3000 OBJECT SENSOR IR 500 2 1000 LED LIGHT 20 1 20 L CHANNEL MATERIAL 1500 1 1500 PAINT 500 350 OTHER 3000 2500 MODULE TOTAL Estimated cost = Rs 14320 Final cost = Rs 13670 Hence the project is feasible as per price is concerned 13670 24 7. ADVANTAGES AND DISADVANTAGES 7.1 Advantage: 1. Minimises Expenditure Automated conveyor systems would speed up productivity. The work can get done faster and with less energy and people than with manual equipment. It is an economical investment. 2. Improved efficiency Workers are better able to do their tasks using automated equipment, meaning they can work much more efficiently. The automated conveyor system will consume less energy for the same amount of material transport compared to traditional conveyor system as it has the ability to sense when it has to work and when to stop. 3. Reduce accidents Employee safety is a top concern for businesses in the industrial sector. As this conveyor system stays idle when there is no material on it to transfer there is a reduced chance of accidents to occur. 4. Avoiding Fatigue As there involves idle time when there is no material on the conveyor, the continuous working of the belt and associated equipment are avoided. Eventually the lifespan of conveyor increases to a great extent. 7.2 Disadvantage: 1. Initial cost of equipment The initial cost for IR equipped smart conveyor system would be high. However, the less energy consuming and automatic smart conveyor will eventually pay for itself. 25 2. Reduced flexibility for change Once systems are in place, it is likely not as easy to make changes in your workspace. But once you go automated and see how smoothly everything runs, it’s not likely you’ll want to return to manual equipment afterward. 3. Possible downtime due to malfunction With automatic machines there is always the chance of a problem or breakdown, which can lead to considerable downtime while it is repaired. If the problem cannot be fixed by anyone on site, an outside specialist may need to be called, which could mean more time spent waiting. Equipment malfunction can be avoided in most cases with routine maintenance of all machinery. If proper care is taken to keep automated systems in good shape, breakdowns should only occur rarely. 4. Maintenance costs Equipment needs maintenance. Routine maintenance may be performed regularly by onsite workers, but periodic professional maintenance should be handled by specialists who are trained to inspect and tune-up machinery so that it runs smoothly and efficiently, easing the overall lifespan of your systems. 26 8. CONCLUSIONS By employing the automatic conveyor at the level crossing, the arrival component, we can reduce the consumption, neglect the unwanted motion of the conveyor and to avoid wastage on life duration of conveyor and its equipments 27 9. FUTURE SCOPE Further much more accessories and modifications such as 1. use of variable speed gear motor and 2. pocket belts will increase its applications, effectiveness in various fields. If the enlarge scaling of machine is done then it may be used to accurately count the large object such as in food processing industries. 28 10. REFERENCES 1. Konakalla Naga Sri Ananth1, Vaitla Rakesh2, Pothamsetty Kasi Visweswarao – “Design and Selecting the Proper Conveyor-belt” - International Journal of Advanced Engineering Technology Vol. 4 issue 2- April 13, 2012 2. Shalom Akhai, Harpreet Singh. - “Design Optimization for Modification of Trough Belt Conveyor to Reduce Material Spillage Used in Clinker Transport in Cement Plant” - International Journal of Research in Advent Technology - Volume 1, Issue 4, November 2013 3. Tasmin F. A riff, Muhd. Fahmi B. Jusoh, Malek Parnin and Mohd. Hanif Azenan. - “Design Improvements and Fabrication of Conveyor Belt Cleaner and Washing System at Westports Malaysia” - International Journal of Education and Research -Vol. 1 No. 10 October 2013 4. Suhas M. Shinde and R.B. Patil – “Design and Analysis of a Roller Conveyor System for Weight Optimization and Material Saving” - International Journal on Emerging Technologies- 25 April, 2012 5. Ilesanmi Afolabi Daniyan, Adefemi Adeodu And O M Dada – “Design of A Material Handling Equipment: Belt Conveyor System for Crushed Limestone Using 3 Roll Idlers” – Journal of advancement in engineering and technology January 16, 2014.