الفهرس 
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Abstract
Formaldehyde is produced by oxidation of methanol in gaseous state. Current production of formaldehyde uses look-up table and proportional and integral (PI) feedback control to regulate the flow rates of both methanol and air independently, which is not efficient, not safe and not robust to process parameter uncertainty.
Developing a controller for controlling both air mass flow rate and methanol volume flow rate is considered in this work. The approach used to carry out this task is based on perfonning design to implementation work. The system under study is divided into two loops. The first is the air loop and the second is the methanol loop. A fan and a pump with two different drives are used to drive this system. A controller is designed to achieve the required system performance in different modes of operations, supported with a friendly Graphical User Interface (GUI) control panel. The controller adjusts the motor speed of the fan depending on the required flow set point for the air. It also adjusts the speed of the pump to get the required flow of methanol. The controller is optimized to produce minimum steady state error and minimize rise time and overshoot. A model is introduced in order to study the system response. Simulation is carried out using MA TLAB I SIMULINK.
The hardware implementation of this work is carried out using LabVIEW. So, LabVIEW 2009 software is used with AID and D/A interfaces. The software controller digitizes the error current and produces the correction current based on the flow rate feedback signal from a flow meter.
The developed controller is controlled by a designed GUI that runs on the same computer for monitoring the performance of the ystem. Experimental results and discussion are introduced to represent the improvement of the system performance.
Keywords: LabVIEW 2009, PI controller, Fuzzy Logic Controller, Flow control, Ratio control.