Automatic production line
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Date
2014
Authors
Omar Husni Odeh
Omar Taher Toffaha
Saad Sami Halaweh
Yahya Hisham Abu bieh
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Abstract
One Palestinian tin-cans manufacturing company faces a problem of discontinuity of manufacturing. The tin-plates are treated manually with synthetic adhesive, and dried at room temperature and conditions. Then the dried plates collected and conveyed manual to the next manufacturing line fix the proper place on the body of the can .These steps delay the processing. This project aim to achieve these operations continuouslyA Conveyor, is a mechanized device used to move materials in relatively large quantities between specific locations over a fixed path. Conveyors are especially useful in applications involving the transportation of heavy or bulky materials. Conveyor systems allow quick and efficient transportation for a wide variety of materials, which make them very popular in the material handling and packaging processes. There are many kinds of conveying systems, and are used according to the various needs of different processes.The process for the production line is to transport rubber-coated tin plates on a conveyor which moves in a certain velocity, the coated rubber needs to be dried while plates are translating on the conveyor. Thus, the conveyor should be designed on the basis of many specifications such as conveyor velocity, shape, length, step width, roller or treadmill conveyor, friction with belt, horsepower, total weigh of plates, drying time and sensitivity of the sensor.The factory suffers from a big problem in which the coated tin-plates need to be dried. So labors move these work-pieces from the coating machine to a sunny location and expose these plates to the sunlight for four consecutive hours in order to dry them well. This long and arduous process takes so much time for the plates to be prepared for the subsequent production processes which in turn affects the productivity of the factorySo the problem swirls around how to improve this production line. After studying this trouble, we came up with an appropriate solution in which we use a combined production system consisting of a conveyor, dryer and counting sensor. The existence of the conveyor will facilitate the process of handling the tin-plates, reduces the time consumed in moving the plates from one place to another, improves the productivity of the factory and increases the overall efficiency of process. The types of products to be conveyed are tin plates 30cm X 30cm, 20cm X 15cm and 20cm X 10cm all have 1 mm thickness in a widthwise manner, these plates are to be placed on the conveyor manually, the method of transportation is powered belt conveyor and it will be used for a shift daily. Drying is concerned with the removal of water from process materials and other substances. The term drying is also used to refer to removal of other organic liquids, such as benzene or organic solvents, from solids. Drying in general, usually means removal of relatively small amounts of solvent from materials. Drying process for our project depends on the temperature, air flow and time, where we will design a process that works on drying adhesive sample within the fastest time possible.That we will design process similar to the process dehydrators drying in terms of the mechanism of action. A dryer will be installed along the conveyor to allow the drying process of the rubber-coated plates while they are moving on the conveyer, the newly-rubber painted plates enter the conveyor where the rubber is still liquid, as they move on the conveyor, a hot air flow strikes the plates and leads to dry the rubber gradually, the hot air inside the dryer will not cause the conveyed plates to fly from its place. According to our experimental results, it takes about 1 minute at an air flow rate of 80 Liter/second for the rubber material to be completely dried inside the dryer which provide a uniform distribution of heat, so after one minute of entering, the plates now are on the exit of the conveyor where a counting IR sensor is mounted there in order to count how many plates leaving the conveyor. The plates leave the conveyor to be arranged on the shipment board where a proximity displacement sensor is located there, if the height of the plates accumulated over each other (column-by-column filling) reaches a certain height, the proximity sensor gives the mechanized shipment board an order to move a specific distance to allow the filling of the next column and so on. Electric motors are all around us, from common appliances to our most sophisticated computers. In fact, the technology has been present for over a century, with many of the earliest motor types still in broad use. Motors provide motion. Whether rotating or linear, motors enable us to move people and machines. They impact every aspect of our daily lives. Electric motors are clean and relatively efficient for the tasks they perform when compared to pneumatic or hydraulic alternatives. In our project, all DC motors are excluded from the selection because the tin works factory operates at 3 phase system and the owner did not want us to dig in control. AC motors are the most suitable type of motors to be operated in such a project. Synchronous motor can't be operated because the starting torque is zero and this is the most important factor in the section of motor selection where the starting torque should not be zero in order to initiate the motion of the production line. Another choice is : 3-phase induction motor which is available in the market with approximately all power and torque ratings. The 3-phase induction motor is the most commonly used industrial motor, finding applications in industrial machineries where speed regulation is not essential. It is simple and relatively inexpensive, and the absence of sliding contacts with the rotor reduces maintenance to minimum. There are two general types of 3-phase induction motors : the squirrel-cage type and the wound-rotor type. Both motors have a stator structure similar to that of synchronous generator, consisting of three individual windings which overlap one another and offset by an electrical angle of 120 degrees. The phase displacement between the voltages applied to the stator windings produces a travelling MMF or rotating magnetic field in the uniform air gap. This field links the short-circuited rotor bars, and the relative motion induces short circuit currents in them, which move about the rotor in exact synchronism with the rotating magnetic field. It is well known that any induced current will react in opposition to the flux linkages producing it, resulting herein a torque on the rotor in the direction of the rotating magnetic field. This torque cause the rotor to revolve. If the rotor were to revolve at exactly synchronous speed, there would be no changing flux linkages about the rotor coils and no torque would be produces. However, the practical motor has friction losses requiring some electromagnetic torque, even at no load. It is important to mention that the torque of the three-phase induction motors is zero at the synchronous speed and there is a maximum torque called pullout torque which is two or three times greater than the rated full load torque. The starting torque of there-phase induction motors is slightly larger than its full load torque, so the motor is able to start carrying any load. Unlike the three-phase synchronous motors which have zero starting torque. According to what was mentioned above, the three-phase induction motor appears to be the best choice for such a project. Gains and benefits of the project:The designed production line has the same efficiency of any imported one. Therefore we can talk in savingIn design costsIn fulfillment, establishment and erection costsIn used materialsEasy to make maintenance and to exchange any defect parts.Beside that it encourages the employer to go into further developments. In another word the employer will provide work opportunity to local engineers and local material suppliers. As a resultant such works helps in economic growth in micro levels.