Design and simulation of an automated batch vacuum pan control system for sugar crystallisation.

Abstract

In Uganda sugar is manufactured from sugar cane and about 60%ofsugar produced-worldwide is from sugarcanes which is a perennial grass containing sucrose. This project deals with control system for a batch vacuum pan during sugar crystallisation by controlling. the temperatures and feeding of materials automatically and monitors super saturation and crystal content online. Sugar crystallisation has been for quite long time-when it manual and its associated with a lot of problems such as labour intensive, wastes energy, time consuming, variation in quality that is size and colour of sugar: The research of the study was conducted at GM Sugar Ltd located in Buikwe District, Nakibizi by carrying out extensive literature review, observation, consultation and laboratory test by use of refractometers, Polari meter to know the purity and brix of materials so as to exactly know about the problem so as to generate a solution for it during production of a sugar for commercialisation From research the major parameters were super saturation, crystal content, temperature and feeding of materials, therefore the control system was designed by modelling different equations for each parameter and their relationship was determined. The code was developed by use of Arduino software with the help of language C, and the simulation diagram was designed in the simulation environment in Proteus software to enable the code to be loaded on the circuit to run the system and results were displayed on the LCD. The control system contains four sensors which measure and send signals to the micro-controller for it to make decisions and tell acuactuator valves alarms and led light on what to be done. The temperature ranges of crystallisation was between 65-700Ci average initial crystal content was 24% and feed level of materials were 40% Syrup above the calandria at the start of the process, 30% seed when super saturation is 10006 20% syrup when crystal content is at 32% and finally 1.0% syrup when crystal content is at 12% therefore the crystallisation ends when crystal content is above 48% and showed that it requires 2.5 hours for crystallisation to end since, parameters were controlled properly and in 6.5 minutes the crystal content would have increased by 1%. On the simulation circuit the parameters were varied on the sensors to test its validity, results were displayed on the LCD and relation was observed. The economic evaluation of the project was carried out by use of NPV method and it showed that the project is viable once it's being implemented Since estimated initial investment was 28,000000 UGX and in five years the estimated NPV was 1,280,900. The control system increased the quality of sugar and production, cost of production and down. time. was reduced and energy was saved therefore much has been done but further work is needed on control of crystal size distribution and circulation of massecuite plus the control. of parameters during production of B sugar and C sugar.