ABSTRACT
The aim of this project was to develop and test a microcontroller-based column scanner prototype, where data is transmitted wirelessly, stored and displayed on to a handheld controller module to show a scan profile of the column in real-time. A laboratory-scale scanner prototype was constructed using a wood frame; 1 m length and 0.5 m width and a circular acrylic material (diameter 25 cm and radial width 10 cm) that houses a low activity source, 114 mCi 241Am radiation source (NER-492, S/N: A-377) and Velleman K2645 GM detector. The scanner is operated by two 12 VDC geared motors and two- timing belts to drive the source-detector assembly, in both vertical and horizontal plane, along the column frame for preset increment heights of 5-10 cm movements for auto counting at the preselected preset time between 1-10s. Current scanning systems are limited to only vertical scan movement and cabled. Ultrasonic proximity sensor and 3- axis accelerometer were used to determine and limit both vertical and horizontal plane orientations of source-detector, respectively. The GM detector was connected to a microcontroller-based circuit which also controls the movement motors. Four 2.4 GHz nRFfl2401 radio modules facilitated wireless communication between the scanner and the handheld module within a radius of 100 m. A handheld controller module consisting an LCD display screen (3.5” x 2.5”) was used to display the scan configurations and results. The software used to run the microcontrollers for both scanners and the handheld module was developed using the Arduino IDE, which is an open-source software using C++. The scanner offers the option to operate in both gamma scanning mode and for use in radio tracer measurements. In gamma scanning, two modes of operation are possible; automatic and manual counting. In radiotracer measurement mode, the detector is maintained in a fixed position for counting to assume a typical field radiotracer measurement. Reliability and safety features used included: CRC, Limit switch, 3-axis accelerometer and Internal watchdog. The model column is an 8” diameter PVC pipe fitted with two 5 cm wide, 6 mm mild steel rings at 22 cm intervals to represent distillation column and separation trays in a typical industrial process setup was tested for faults using the prototype. From the scan profile generated in gamma column scanning test, it was possible to locate the two separation trays and the simulated malfunction. The obtained results were validated through a comparison with the actual physical measurements. For radiotracer experiment, the instantaneous introduction and withdrawal of the radioactive source at different time intervals was detected from the profile drawn in real-time display on the LCD screen with peaks corresponding to the various time intervals of radioactive source introduction and withdrawal. This project has demonstrated the possibility for the adoption of wireless control of gamma-based column scanners and wireless data transmissions to increase efficiency, minimize personnel exposure through increased operation ranges by eliminating cabling, reduced costs of operation, and has the potential to use in the harsh industrial environment. However, this prototype is suited only for laboratory demonstrations on practical applications of gamma column use in the diagnosis of industrial processes.
TABLE OF CONTENTS
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
LIST OF FIGURES 11
LIST OF TABLES 12
LIST OF ABBREVIATIONS AND ACRONYMS 13
CHAPTER ONE
INTRODUCTION
1.1 Background to the study 14
1.2 Statement of the Problem 16
1.3 Research Objectives 16
1.3.1 Main objective 16
1.3.2 Specific objectives 17
1.4 Justification and Significance of the Study 17
1.5 Scope and Limitations of the Study 17
1.6 Organization and Structure of Thesis 18
CHAPTER TWO
LITERATURE REVIEW
2.1 Chapter Overview 19
2.2 Microprocessor applications and Microsystems 19
2.2.1 Optimization of Microprocessors with Respect to Computational paradigms 21
2.3 Internet of Things (IOT) 21
2.3.1 Sensors in IoT 22
2.3.2 Communication in IoT 23
2.3.3 Data Signal processing in IoT 23
2.3.4 Data compression 24
2.3.5 Data security 24
2.4 Embedded systems. 25
2.4.1 DC Motor Speed Control 26
2.4.2 Wireless communication network systems 26
2.5 Gamma Column Scanning and Radiotracer Measurements in Industries 27
CHAPTER THREE
THEORETICAL FRAMEWORK
3.1 Chapter Overview 30
3.2 Methods Used in Gamma Column Scanning 30
3.2.1 Classical Gamma Column Scanning Method 30
3.2.2 Modern Gamma Scanning 30
3.2.3 Gamma Radiation Detectors 32
3.2.4 Principles of Radiotracer Measurements 32
3.3 Data Acquisition and processing in Measuring Systems 36
3.3.1 Data Signal Sampling 36
3.3.2 Noise in Data Signals 37
3.3.3 Data Transmission 38
3.3.4 Digital Signal Processing 40
3.4 Nibras Data Acquisition Systems 40
CHAPTER FOUR
METHODOLOGY
4.1 Chapter Overview 43
4.2 System Design and Construction 43
4.3 Components used in the designed system development 47
4.3.1 Arduino Mega 48
4.3.2 DC Geared Motors 48
4.3.3 A 3.5” Thin Film Transistor LCD Screen 49
4.3.4 nRFL2401 Radio Module 49
4.3.5 433 MHz Transceiver and Receiver Pair Module 49
4.3.6 MPU6050 3- Axis Accelerometer 50
4.3.7 Ultrasonic Proximity Sensor 50
4.3.8 Power supply 50
4.3.9 Velleman K2645 Geiger Muller Detector 50
4.3.10 DC Motor driver 51
4.3.11 A Limit switch 51
4.3.12 Circular acrylic detector-source assembly 51
CHAPTER FIVE
RESULTS AND DISCUSSION
5.1 Chapter Overview 54
5.2 Overview of the developed prototype system 54
5.2.1 Scanner head system 54
5.2.2 Control Module system 56
5.2.3 Software Development 59
5.2.4 Scanner Data Acquisition 63
5.2.5 Scanner Data Transmission 63
5.2.6 Data Treatment in Control module: Reception, Buffing, Arraying and Plotting 64
5.2.7 System Validation for Reliability and Safety 65
5.3 Test Results 67
5.3.1 Gamma column scanning setup 67
5.3.2 Radiotracer Configuration for Laboratory Measurements 73
CHAPTER SIX
CONCLUSIONS AND RECOMMENDATIONS
6.1 Conclusions 77
6.2 Recommendations 77
REFERENCES 79
APPENDICES 87
Appendix I: Components Specifications 87
Appendix I1: System Booting and Distance Reading 90
Appendix III: Obtaining Scanner Orientation 76
Appendix IV: Scanner State Transitions 79
Appendix V: Scanner Movement 82
Appendix VI: Data Receiver and Utility Checks 88
Appendix VII: Gamma Chart Plotting Code 92
Appendix VIII: Plotting Radio Tracer Chart Points 99
Appendix IX: Detector Code 116
Appendix X: nRFL2401 and 433MHz RF Code 101
Appendix XI: Command Checking and Execution. 104
Appendix XII: EEPROM code 127
LIST OF FIGURES
Figure 1.1: Detector-source arrangement and scan profile 15
Figure 3.1: Radiotracing operation 33
Figure 3.2(a): Radiotracer application in flow measurement 34
Figure 3.2 (b): Scan profile for pulse velocity flow measurement 34
Figure 3.3: Leak detection using radiotracer 35
Figure 3.4: Short-circuit determination using radiotracer. 35
Figure 3.5: Nibras System circuit 41
Figure 3.6: Nibras System display 41
Figure 3.7: PC connection for Nibras system. 42
Figure 4.1: Outlook of the conceptualised automated gamma scanning system prototype 43
Figure 4.2: Block diagram of the designed gamma scanning system prototype 44
Figure 4.3: The conceptualised graphical model of the physical system. 45
Figure 4.4: Scanner frame assembly unit 46
Figure 4.5(a): Schematic diagram of scanner head module components. 47
Figure 4.5(b): Schematic diagram of handheld control module components. 48
Figure 4.6: (a) Voltage divider schematic, (b)Velleman K2645 GM 51
Figure 4.7: Design sketch of the Circular acrylic assembly 53
Figure 5.1: Constructed Scanner Head Features assembly – top view. 55
Figure 5.2: Scanner Head circuitry component layout. 56
Figure 5.3: Wireless controller circuitry component layout. 57
Figure 5.4: Keypad buttons component layout. 57
Figure 5.5: Keypad buttons electrical design circuit. 58
Figure 5.6: Constructed Wireless Handheld Control module. 58
Figure 5.7: State machine coding flowchart for the developed system. 60
Figure 5.8: Software execution for scanner head/control module/user flowchart. 61
Figure 5.9: Software execution for operator/control module flowchart. 62
Figure 5.10: Sample of Scanner data serialization code 64
Figure 5.11: HC-SRO4 -Ultrasonic sensor calibration. 66
Figure 5.12: Scanner head system outlook with the model column. 68
Figure 5.13: The developed wireless handheld controller module 69
Figure 5.14: Menu options display for mode on the wireless controller. 70
Figure 5.15: Menu options display for parameter selection on the wireless controller. 71
Figure 5.16: MATLAB vs LCD column profile plots. 72
Figure 5.17: (a) Radiotracer scan simulation results on display 74
Figure 5.17: (b) Scan profile of radiotracer data using MATLAB 74
LIST OF TABLES
Table A1.1: Arduino Mega Specifications 87
Table A1.2: 12V DC motor Specifications 87
Table A1.3: nRFL2401 Specifications 88
Table A1.4: 433 MHz RF Transmitter Module Specifications 88
Table A1.5: 433MHz RF receiver module specifications 88
Table A1.6: Power supply rating calculation 89
LIST OF ABBREVIATIONS AND ACRONYMS
ABS - Acrylonitrile Butadiene Styrene ADC - Analog-Digital Converter
AI - Artificial Intelligence
CNC - Computer Numerical control CRC - Cyclic Redundancy Check
DC - Direct Current
EEPROM - Electrically Erasable Programmable Read Only Memory. GDP - Gross Domestic Product
GM - Geiger Muller
IDE - Integrated Development Environment. LCD - Liquid Crystal Display
LSB - Least Significant Bit
NER - Named Entity Recognition
PC - Personal Computer
RX - Receiver
SDRAM - Synchronous Dynamic Random-Access Memory SRAM - Static Random-Access Memory
TFT - Thin Film Transistor
TX - Transmitter
USB - Universal Serial Bus
VDC - Volt of Direct Current
CHAPTER ONE
INTRODUCTION
1.1 Background to the study
Industrialization is one of Kenya’s long-term development goals towards the achievement of Vision 2030 goals. Currently, the government has identified four areas to invest in, branded as ‘The Big Four Agendas’; the manufacturing sector, health, housing and food security. The government aims at increasing the GDP share in the manufacturing sector from the current 9.2% to 20% by the year 2022. Nevertheless, the potential of application of Non-Destructive Nuclear Techniques is not significantly utilized to date (Ngui et al., 2016).
The Kenya Government recognizes the role of nuclear science applications as a prerequisite for sustainable social and economic development, in general. Nuclear applications are widely used in; medicine, manufacturing and industry, agriculture and food security, development of water resources, development of energy resources, and in research institutions, for various multi-disciplinary studies. Nuclear technology finds a wide range of application in industrial and medical fields; specifically, these include the following techniques; Computed Tomography Scan, X-ray radiography, gamma column scanning, radiotracer measurements, among others (Kim et al., 2011).
Gamma scanning technology is usually applied in industries to diagnoses the various processes. The method utilizes a radioactive source that emits radiations and a radiation detector, which records the density profile. Such industrial processes include; flow measurements, process equipment/systems, leakage detection of buried pipelines, residence time distributions, isotope hydrology and water resource management, sediment transport study, among other uses (Kim et al., 2011). In principle, Gamma column scanning is widely employed in the inspection of anomalies involving columns in oil refineries and petroleum industries and reactors. These columns may be a tray or packed distillation and fractionation towers. In this method, the detector and the sealed source of radiation move simultaneously opposite in the same horizontal plane along the column being diagnosed, as shown in Fig.1.1 in which the intensity readouts show the internal profile of the column (Froystein et al., 2005).
Figure 1.1: Detector-source arrangement and scan profile (Source: Sanches et al., 2007).
Analysis of the generated profile through analysis software and comparing it with perfect mechanical design can enable one to deduce valuable conclusions about the equipment's functionality (Johansen, 2005). Examples include; deformed or displaced separation trays and even finer details relating to whether the column is entrained or flooded (Benahmed and Alami., 2012). These findings are helpful for process engineers and plant operators identify process anomalies, optimize performance, and initiate maintenance operations where necessary. Optimized columns are profitable to the company and also yield up to standards products.
The existing gamma scanning systems are made up of a winched system to lower or raise the source and detector and a wired communication system to a computer or laptop running data logging and analysis software for the recorded radiations (Stoddart, 1979). Such systems are manually operated by lowering the source and detector simultaneously with a data logger connected through cabling, which restricts the study to limited coverage. In some cases, the environment may be harsh and constrained, thereby requiring several assistants to do measurements. This system also requires the person to operate within the immediate vicinity, which exposes him/her to the radiations.
An automated scanning system with wireless data acquisition and control can increase efficiency, safety, accuracy, and reliability of data and is easily accessible to the harsh environment compared to manual operated systems (Walinjkar et al., 2009). This research project aimed at developing a fully automated gamma column scanning system with wireless data acquisition and control. This research was motivated by the need for a low cost, portable, safe, easy to operate, modular scanner for separation columns with reduced cabling and a more flexible and versatile system for radiotracer studies.
1.2 Statement of the Problem
The need for online diagnosis of industrial processes is vital for the optimized operation of the equipment. The complexity in the design, layout and operation of this process equipment necessitates non-destructive testing in real-time validation and investigation of the process models. The system currently in use, is cabled in nature. This feature limits it to studies in only small coverage. Furthermore, most industrial processes are operated under harsh conditions which are hazardous to human health. The current system that restricts the researcher close to the vicinity under investigation during study becomes unsuitable for long time studies in such circumstances. Radiation safety is highly recommended in the handling of radioactive sources. However small it might be, free doses should be avoided. The existing system subjects the researchers to long exposure time since it is not possible to conduct the investigative studies remotely. Its cumbersomeness and manually intensive nature added to the high cost of acquiring the equipment proves the existing system to be uneconomical.
1.3 Research Objectives
1.3.1 Main objective
This work aimed to design and develop a low-cost microcontroller-based automated gamma column scanner head with a wireless data acquisition system.
1.3.2 Specific objectives
(i) To develop a fully automated gamma scanning head system with dual-axis movement capabilities;
(ii) To develop a portable control module with capabilities for data treatment, control of the scanning head and detector - source movement.
(iii) To develop a wireless communication system between the control module and the scanner head.
1.4 Justification and Significance of the Study
Gamma distillation columns are vital in manufacturing industries, especially ones dealing with products that require distillation. Regular gamma scanning is required to maintain these columns in a good working condition, which helps maintain quality products, reduce operational costs, and meet regulatory requirements. Such regulatory requirements are put into place to safeguard consumers against bad quality, limit energy consumption and safeguard the environment against pollution. Current gamma scanning systems are human-intensive, its limited to only one scan line at a time since it can only move vertically, simultaneous movement of the source and detector involve several stages of scanning which can run into several hours if not days due to need for further analysis using computer software. Cabled communication limits the study area, especially in radiotracer measurements, while confining the personnel within the vicinity of high radiation exposure. There is therefore a need for a microcontroller-based system with motorized source and detector movement in dual axis, wireless control and data transmission, and real-time scan results. This will significantly increase reliability and accuracy, reduce radiation exposure risks, and lower gamma scanning systems and operations costs.
1.5 Scope and Limitations of the Study
In this project, a microcontroller-based lab-scale gamma scanner prototype has been designed and constructed. The prototype developed provides for the following salient features; motorized vertical and horizontal movement, scan data acquisition, and wireless transmission within a radius of not more than 100 m to a hand-held battery-powered control module, data treatment and graphical display on miniature LCD. The prototype was designed for only one detector and tested using a low activity radioactive source Am- 241,114 mCi after configuration. The results were acquired compared with the physical trays locations and characteristics.
1.6 Organization and Structure of Thesis
This thesis contains six chapters and an appendix. The design and development of the scanner methodology, data acquisition, processing and transmission, system hardware design, system control and wireless communication system, software and data treatment is discussed in detail in the main chapters. The appendix contains supporting information on the code developed to run the systems. Chapter 1 discusses the background of the research area, objectives and the scope of the study. Chapter 2 reviews literature with studies done on Microsystems and Microprocessor applications, Internet of things, Embedded systems, DC motor control and wireless communication networks. Chapter 3 reviews the theoretical principles on the existing systems for classical and modern ways of industrial gamma scanning, methods and applications, types of gamma radiation detectors, data acquisition and signal processing, and various modes of wireless communication Chapter 4 focuses on the methodologies used in the design, materials/components and development of both the hardware and software to produce a reliable system that meets the objectives of this project. Chapter 5 primarily provides the results and discussions of the prototype developed and validation of the prototype. Chapter 6 concludes the thesis with discussion and recommendation drawn from the study. Appendix contain the codes of various operations within the system, mainly in; data acquisition and processing, control, transmission, display and treatment.
Click “DOWNLOAD NOW” below to get the complete Projects
FOR QUICK HELP CHAT WITH US NOW!
+(234) 0814 780 1594
Login To Comment