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Thank you: COMMENTS: 2008-08-28T23:36:20+09:00 http://engineeringreport.atwiki.com/page/1111 11111 2008-07-15T09:07:24+09:00 http://engineeringreport.atwiki.com/page/comment_plugin1 ==comment plugin test (above) with wiki-mode== **comment plugin** is __creating comment-form with wiki.__ Example) **@@comment(above)@@** is ------- @@comment(above)@@ 2008-06-05T11:13:49+09:00 http://engineeringreport.atwiki.com/page/Group%201 Group members 2008-05-02T16:36:16+09:00 http://engineeringreport.atwiki.com/page/comment_plugin2 ==comment plugin test (below) with wiki-mode== **comment plugin** is __creating comment-form with wiki.__ Example) **@@comment(below)@@** is ------- @@comment(below)@@ 2008-03-16T14:06:49+09:00 http://engineeringreport.atwiki.com/page/Electrical%20Engineering Electrical Engineering Reports 2008-02-15T03:50:25+09:00 http://engineeringreport.atwiki.com/page/Group%205 Group members 2007-08-15T06:29:11+09:00 http://engineeringreport.atwiki.com/page/Nur%20Sharlinawati%20Md.%20Said CHAPTER 1   INTRODUCTION   This chapter will briefly describe the background of the study which contained the description of the batch polymerization reactor, PID controller, polyethylene polymer and Aspen Plus programmer. The problem statement will discuss about why this research is done. It is also include the objective and scope of this research which will be what do I want to achieve in this research and the simulation is run under the certain scope.      1.1 Background of Study    1.1.1        Batch Polymerization Reactor A batch polymerization reactor is jacketed, has a stirred tank. The reactor is rated for certain temperatures and pressure range which is 0-200oC and the pressure is 80 psig of full vacuum for 30 gallons tank. This reactor is widely used in the industry because of its operational flexibility which can be attractive and challenging in solving the industry’s control problems due to its nonlinearity, complexity, variability and uncertainty of the reactor.     1.1.2        PID Controller PID controller is a proportional-integral-derivative controller which is a generic control loop feedback mechanism had widely been used in the industry control systems. The PID controller attempts to correct the error between a measured process variable and a desired set point by calculating and then outputting a corrective action that can adjust the process accordingly.   From the algorithm calculations of the PID controller, it involves three separate parameters which are; the Proportional, the Integral and Derivative values. The Proportional value determines the reaction to the current error, the Integral determines the reaction based on the sum of recent errors and the Derivative determines the reaction to the rate at which the error has been changing. The weighted sum of these three actions is outputted to a control element such as the position of a control valve or power into a heating element.   By "tuning" the three constants in the PID controller algorithm the PID can provide control action designed for specific process requirements. The response of the controller can be described in terms of the responsiveness of the controller to an error, the degree to which the controller overshoots the set point and the degree of system oscillation.     1.1.3        Polyethylene Polymer Ultra high molecular weight polyethylene (UHMWPE), also known as high modulus polyethylene (HMPE) or high performance polyethylene (HPPE) is a thermoplastic. It has extremely long chains, with molecular weight numbering in the millions, usually between 2 and 6 million. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. These results in a very tough material, with the highest impact strength of any thermoplastic presently made.   It is highly resistant to corrosive chemicals, with exception of oxidizing acids. It has extremely low moisture absorption, very low coefficient of friction, is self lubricating and is highly resistant to abrasion (15 times more resistant to abrasion than carbon steel). Its coefficient of friction is significantly lower than that of nylon and acetal, and is comparable to Teflon, but UHMWPE has better abrasion resistance than Teflon. It is odorless, tasteless, and nontoxic.     1.1.4        Aspen Plus Program Engineers are constantly being called upon to predict the behavior of systems. Chemical engineers in particular must be able to predict the actions of chemical species, a very difficult task.   Thus the ASPEN PLUSprogram allows to create our own simulation process model, starting with the flow sheet, then specifying the chemical components and operating conditions. ASPEN PLUS will take all of the specifications and we can simply simulate the model. The process simulation is the action that executes all necessary calculations needed to solve the outcome of the system, hence predicting its behavior. When the calculations are complete, ASPEN PLUS lists the results, stream by stream and unit by unit and we can observe what happened to the chemical species of the process model.   1.2 Problem Statement The chemical process industries are faced with an increasingly competitive environment, ever-changing market conditions, and government regulations. Yet, they still must increase productivity and profitability. Bottom line performance can be adversely affected by a many factors, such as production economies and product quality. Many of these factors are extremely complex and subject to varying degrees of unpredictability.   Process engineers routinely address these difficult issues. They are faced with challenges that range from the designing new processes to evaluating and improving performance of existing plants while they address these business objectives. By experiencing alone is not always the sufficient to answer the questions that continually arise. Efforts which are needed to provide meaningful insight is costly and potentially dangerous. To avoid production delays, downtime or off-spec product, process manufacturers require cost-effective tools that help identify and correct anticipated problems before they occur.   Previously there were researches done by few people to investigate the effect of temperature by using batch polymer reactor. But in those cases they used PID-fuzzy controller which is the most suitable with the dynamics change with the operating point and there might be other essentials nonlinearities in the process (Ljung, 1996). The variety application of this controller indicates that this technique has becoming the important tool for complex process (Lee, 1990). They found that this is the promising way to deal with industrial control problems.   Thus, this research is done to investigate the effect on the polymer’s gain concentration by using the same controller which is the PID controller. This simulation will be design by using Aspen Plus program. By the end of the simulation we will manage to determine weather the PID controller is also the most suitable controller to achieve the optimum value of the gain concentration.   1.3 Objective Designing batch polymerization reactor by using Aspen Plus to obtain an       optimum value of the gain concentration.   1.4 Scope This simulation process will be done under these scopes of experimental, which are:      1. This polymerization process will be done by using by only bract reactor.      2. To obtain the optimum gain concentration the simulation will be controlled           by PID controller.       3. This simulation process will only use the polymer.      4. The simulation process will be designed by using Aspen Plus. 2007-08-09T03:23:11+09:00 http://engineeringreport.atwiki.com/page/Chemical%20Engineering Chemical Engineering Reports 2007-08-09T03:10:19+09:00 http://engineeringreport.atwiki.com/page/Menu ==menu== * [[FrontPage]] * [[Menu]] ---- ==recent list 20 == @@recent(20)@@ ---- 2007-08-09T02:25:48+09:00