DESIGN, FABRICATION, AND TESTING OF A SCREW PRESS BRIQUETTING MACHINE
ABSTRACT
Globally, there exist a continuous increase in the demand and cost of energy. There is continuous pollution of the atmosphere as carbon dioxide is emitted continuously into the atmosphere as a result of man’s use of fossil fuels for everyday activities. Deforestation is highly practiced in Nigeria, most especially in her rural areas as people rely on wood for domestic cooking and other heating purposes due to the high cost of conventional fuels. And so there is a large percentage of carbon dioxide in the atmosphere as the trees are no longer available to take in the carbon dioxide and give out oxygen. This results in the change in climatic conditions globally. Briquetting technology seeks to address this problem as it has less environmental impact when compared to conventional energy technologies. It is waste to wealth technology. Agricultural wastes are readily available in large quantities all over the country. Thus, costs of producing the briquettes is very small.
This study presents the development of a screw press briquetting machine with a grinder attached. Prior to this time, the biomass to be used for briquetting was grinded in a grinding machine before transportation to the briquetting machine for it to be briquetted. Other essential components of the machine are the screw shaft, the die and the heating system made up of two heating elements. When tested, the grinder performed satisfactorily as the particles were grinded to sizes less than 2mm. The machine is easy to use and can easily be maintained locally. The efficiency of the machine is 90%.
TABLE OF CONTENT
CERTIFICATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
TABLE OF CONTENT vi
LIST OF FIGURES xi
LIST OF TABLES xiii
LIST OF PLATES xiv
CHAPTER 1 1
INTRODUCTION 1
1.1 BACKGROUND OF STUDY 1
1.2 STATEMENT OF THE PROBLEM 3
1.3 AIM AND OBJECTIVES 3
1.3.1 AIM 3
1.3.2 OBJECTIVES 3
1.4 SIGNIFICANCE OF THE WORK 4
1.5 SCOPE OF THE WORK 4
CHAPTER 2 6
LITERATURE REVIEW 6
2.1 RENEWABLE ENERGY 6
2.1.1 SOLAR ENERGY 6
2.1.2 WIND ENERGY 6
2.1.3 HYDRO-ENERGY 7
2.2 BIOMASS 7
2.3 WHAT BRIQUETTING ENTAILS 9
2.3.1 TYPES OF BRIQUETTING 10
2.3.2 ADVANTAGES OF BRIQUETTING 10
2.3.3 LIMITATIONS OF BRIQUETTING 11
2.3.4 BRIQUETTING MATERIAL 11
2.4 PRINCIPLES OF A BRIQUETTE MACHINES 14
2.4.1 SCREW PRESSES 14
2.4.2 PISTON PRESSES 14
2.4.3 MECHANICAL PISTON PRESS 14
2.4.4 HYDRAULIC PISTON PRESSES 15
2.4.5 PELLET PRESSES 15
2.5 FACTORS AFFECTING BIOMASS BRIQUETTING 16
2.5.1 EFFECTS OF PARTICLE SIZE 16
2.5.2 EFFECTS OF MOISTURE 17
2.5.3 EFFECTS OF TEMPERATURE OF BIOMASS 17
2.5.4 EFFECTS OF TEMPERATURE OF DIE 18
2.5.5 EFFECTS OF EXTERNAL ADDITIVES 18
2.6 SAWDUST AS A BRIQUETTE MATERIAL 18
2.7 GROUNDNUT AS A BRIQUETTE MATERIAL 20
CHAPTER 3 22
METHODOLOGY 22
3.0 MATERIALS AND METHODS 22
3.1 DESIGN AND ANALYSIS OF SOME MACHINE PARTS 23
3.1.1 DESIGN ANALYSIS OF THE FRAME 23
3.1.2 DESIGN ANALYSIS OF HOPPER, V 24
3.1.3 DESIGN OF GRINDING CHAMBER 25
3.1.3(a) VOLUME OF GRINDING CHAMBER, Vg 25
3.1.3(b) VOLUME OF CHAMBER ENTRANCE, VE 26
3.1.3(c) TOTAL VOLUME OF GRINDING CHAMBER WITHOUT BLADE, VG 26
3.1.3(d) VOLUME OF BLADE SHAFT, VBS 26
3.1.3(e) VOLUME OF BLADES, VBB 27
3.1.3(f) VOLUME OF BLADE WITH BLADE SHAFT, VB 27
3.1.3(g) VOLUME OF GRINDER CHAMBER WITH CUTTING BLADE, VGB 27
3.1.4 DESIGN OF GRINDER CHANNEL 27
3.1.4(a) VOLUME OF GRINDER CHANNEL, VGC 28
3.1.5 DESIGN OF BARREL HOUSING 28
3.1.5(a) VOLUME OF BARREL HOUSING, VB 28
3.1.5(b) VOLUME OF SCREWSHAFT HOUSING, VSS 28
3.1.5(c) VOLUME OF DIE, VC 29
3.1.6 DESIGN OF SCREWSHAFT 30
3.1.6(a) VOLUME OF SCREWSHAFT, VSC 31
3.1.6(b) VOLUME OF SCREWSHAFT FRUSTUM, Vf 31
3.1.6(c) VOLUME OF BARREL WITH SCREWSHAFT 32
3.1.7 TOTAL VOLUME OF BRIQUETTE MACHINE 32
3.2 DIAMETER OF PULLEY 32
3.2.1 DETERMINATION OF THE DIAMETER OF SCREW SHAFT PULLEY, D2 33
3.2.2 DETERMINATION OF THE DIAMETER OF GRINDER SHAFT PULLEY, D3 33
3.3 CALCULATION FOR LENGTH OF BELT 33
3.3.1 LENGTH OF BELT FOR SCREWSHAFT-ELECTRIC MOTOR PULLEY 34
3.3.2 LENGTH OF BELT FOR SCREWSHAFT-GRINDER SHAFT PULLEY 34
3.4 CALCULATION FOR SPEED BELT 34
3.5 COEFFICIENT OF FRICTION BETWEEN BELT AND PULLEY 34
3.6 CALCULATION FOR WRAP ANGLE �S 35
3.6.1 WRAP ANGLE FOR SCREWSHAFT-ELECTRIC MOTOR 35
3.6.2 WRAP ANGLE FOR SCREWSHAFT-GRINDER SHAFT 35
3.7 ANGLE OF CONTACT, ???? 36
3.7.1 ANGLE OF CONTACT FOR SCREWSHAFT-MOTOR, ????1 36
3.7.2 ANGLE OF CONTACT FOR SCREWSHAFT-GRINDER SHAFT, ????2 36
3.8 CALCULATION FOR TENSION OF BELT 37
3.8.1 SLACK TENSION FOR SCREWSHAFT-ELECTRIC MOTOR BELT, T21 38
3.8.2 SLACK TENSION FOR SCREWSHAFT-GRINDER SHAFT BELT, T22 39
3.9 CALCULATION FOR TORQUE, T 39
3.9.1 TORQUE TRANSMITTED BY MOTOR PULLEY, Tm 39
3.9.2 TORQUE TRANSMITTED BY SCREW SHAFT PULLEY 40
3.9.3 TORQUE TRANSMITTED BY GRINDER PULLEY 40
3.10 POWER TRANSMITTED BY THE BELTS 40
3.10.1 POWER TRANSMITTED BY SCREWSHAFT-MOTOR BELTS, Psm 41
3.10.2 POWER TRANSMITTED BY SCREWSHAFT-GRINDER SHAFT BELT, Psg 41
3.11 CALCULATIONS FOR SHAFT 41
3.11.2 POWER GENERATED OF SHAFTS 41
3.11.2(a) POWER GENERATED BY SCREWSHAFT 42
3.11.2(b) POWER GENERATED BY GRINDER SHAFT 42
3.11.2(c) POWER GENERATED BY MOTOR SHAFT 42
3.11.3 TWISTING MOMENT OF SHAFT DUE TO TENSION OF BELT, Mt 42
3.11.4 BENDING MOMENT OF SHAFT DUE TO TENSION OF BELT, Mb 43
3.11.4(a) BENDING MOMENT OF GRINDER SHAFT 43
3.11.4(b) BENDING MOMENT OF SCREWSHAFT 43
3.11.4(c) BENDING MOMENT OF MOTOR SHAFT 43
3.11.5 EQUIVALENT TWISTING MOMENT OF THE SHAFTS, Te 43
3.11.5(a) EQUIVALENT TWISTING MOMENT FOR GRINDER SHAFT 44
3.11.5(b) EQUIVALENT TWISTING MOMENT FOR SCREWSHAFT 44
3.11.5(c) EQUIVALENT TWISTING MOMENT FOR MOTOR SHAFT 44
3.11.6 EQUIVALENT BENDING MOMENT OF THE SHAFTS, Image 44
3.11.6(a) EQUIVALENT BENDING MOMENT FOR GRINDER SHAFT 45
3.11.6(b) EQUIVALENT BENDING MOMENT FOR SCREWSHAFT 45
3.11.6(c) EQUIVALENT BENDING MOMENT FOR MOTOR SHAFT 45
3.11.7 DIAMETER OF SHAFT, d 45
3.11.7(a) DIAMETER OF GRINDER SHAFT 46
3.11.7(b) DIAMETER OF SCREWSHAFT 46
3.11.7(c) DIAMETER OF MOTOR SHAFT 46
3.11.8 MAXIMUM SHEAR STRESS OF THE SHAFTS, ????max 46
3.11.8(a) MAXIMUM SHEAR STRESS OF GRINDER SHAFT 47
3.11.8(b) MAXIMUM SHEAR STRESS OF SCREWSHAFT 47
3.11.8(c) MAXIMUM SHEAR STRESS OF MOTOR SHAFT 47
3.11.9 MAXIMUM BENDING STRESS OF THE SHAFTS, ????b(max) 47
3.11.9(a) MAXIMUM BENDING STRESS OF GRINDER SHAFT 48
3.11.9(b) MAXIMUM BENDING STRESS OF SCREWSHAFT 48
3.11.9(c) MAXIMUM BENDING STRESS OF MOTOR SHAFT 48
3.12 FACTOR OF SAFETY 48
3.13 HEATING SYSTEM 49
3.14 EFFICIENCY OF MACHINE 49
CHAPTER 4 51
RESULTS AND DISCUSSION 51
4.1 PERFORMANCE EVALUATION 51
4.1.1 PRINCIPLE OF OPERATION OF THE BRIQUETTE MACHINE 51
4.1.2 DETAILED DESIGN ANALYSIS OF THE MACHINE ELEMENTS 51
4.1.2(a) ANALYTICAL DESIGN OF THE EXTRUDER STAND FOR DEFLECTION 51
4.1.2(b) FINITE ELEMENT ANALYSIS OF THE EXTRUDER STAND 52
4.1.2(c) ANALYTICAL DESIGN OF THE ELECTRIC MOTOR STAND FOR DEFLECTION 54
4.1.2(d) FINITE ELEMENT ANALYSIS OF THE ELECTRIC MOTOR STAND 54
4.1.2(e) FINITE ELEMENT ANALYSIS OF THE HOPPER 56
4.1.2(f) FINITE ELEMENT ANALYSIS OF THE CONVEYOR 57
4.1.2(g) FINITE ELEMENT ANALYSIS OF THE SCREWSHAFT 59
4.1.2(h) FINITE ELEMENT ANALYSIS OF THE DIE 61
4.2 BILL FOR ENGENERING MEASUREMENT AND EVALUATION (BEME) 63
CHAPTER 5 64
CONCLUSION AND RECOMMENDATIONS 64
5.1 CONCLUSION 64
5.2 RECOMMENDATIONS 64
REFERENCES 65
APPENDICES 69
LIST OF FIGURES
FIGURE 1: Diagram showing the top of the frame 35
FIGURE 2: Diagram showing the hopper 36
FIGURE 3: Diagram of the grinder chamber 37
FIGURE 4: Diagram of the chamber entrance 38
FIGURE 5: Diagram of the grinder blade 39
FIGURE 6: Diagram of the Grinder channel 40
FIGURE 7: Diagram of screwshaft housing 41
FIGURE 8: Diagram of the Die 42
FIGURE 9: Diagram of the Screwshaft 43
FIGURE 10: Diagram showing the diameters of the pulleys 45
FIGURE 11: Diagram of the pulley with respect to the angle of contact 48
FIGURE 12: Diagram showing the various tension on the belts 50
FIGURE 13: The diagram above shows the different fixed part of the machine 65
FIGURE 14: The mesh diagram of the machine stand, showing the different nodes were the stresses are calculated. 65
FIGURE 15: The von mises analyses of the machine showing pictorially the deformation and the stresses at various point on the machine. 66
FIGURE 16: Diagram showing the different fixed point of the motor stand (the green point is welded while the electric motor rest on the purple point. 67
FIGURE 17: Diagram of mesh analysis, showing the different nodes were the stresses are calculated 68
FIGURE 18: Diagram showing the effects of maximum stress on various points of the motor stand 68
FIGURE 19: The diagram shows fixed points were the forces takes effect on the hopper 69
FIGURE 20: The diagram showing the mesh analysis to analyze the different stresses at the nodes 69
FIGURE 21: Diagram showing the deformation of the hopper at maximum stress 70
FIGURE 22: Diagram indicating the fixed points on the hopper 70
FIGURE 23: The diagram showing the mesh analysis to analyze the different stresses at the nodes 71
FIGURE 24: Diagram showing the deformation of the conveyor at maximum stress 71
FIGURE 25: Diagram indicating the fixed points on the screwshaft 72
FIGURE 26: The diagram showing the mesh analysis to analyze the different stresses at the nodes 72
FIGURE 27: Diagram showing the deformation of the conveyor at maximum stress. 73
FIGURE 28: Diagram indicating the fixed points on the screwshaft 73
FIGURE 29: The diagram showing the mesh analysis to analyze the different stresses at the nodes 74
FIGURE 30: Diagram showing the deformation of the die at maximum stress 74
FIGURE 31: Skeletal diagram of the briquetting machine showing the components 75
LIST OF TABLES
TABLE 1: Table shows the % ash that is left after burning (Grover & Mishra, 2011) 26
TABLE 2: The BEME table for the briquette machine 64
LIST OF PLATES
PLATE 1: Overall mass of the extruder stand was calculated by solidworks 84
PLATE 2: Overall mass of electric motor stand was calculated by SolidWorks 85
PLATE 3: SolidWorks rendering of the grinder chamber with conveyor 85
PLATE 4: SolidWorks rendering of the hopper 86
PLATE 5: SolidWorks rendering of the screwshaft 86
PLATE 6: SolidWorks rendering of the briquette machine 87
PLATE 7: Screwshaft under construction 87
PLATE 8: Hopper under construction 88
PLATE 9: Grinder blades under construction 88
PLATE 10: Grinder chamber under construction 89
PLATE 11: Die under construction 89
PLATE 12: Fully constructed briquette machine 90
PLATE 13: Final finish of the briquetting machine 90
PLATE 14: Preliminary design drawing of the briquetting machine 1 91
PLATE 15: Preliminary design drawing of the briquetting machine 2 91
PLATE 16: Preliminary design drawing of the briquetting machine 3 92
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF STUDY
The world today is going green, everyone is thinking about alternative source of energy, the present and most popular form of energy fuel is known for its disadvantageous effect on the ozone layer in the atmosphere. First world countries like the USA, England, Russia and Germany are far ahead searching for alternative source to fuel energy most especially the latter who is the leading country in renewable energy for electricity generation. Developing countries are also looking for ways to go into other sources of energy apart from fossil fuel.For this reason, they have to look around and beyond their immediate environment to create energy.
Biomassareorganicmatterthatisrenewableoverthe course of time.Moresimply,biomassisreservedenergy(Zhang, 2012). Biomass is produced by green plants converting sunlight into plant material through photosynthesis and includes all land and water-based vegetation, as well as all organic wastes. With the principles of biomass, energy from immediate environment like agricultural waste, sawmill/carpentry waste, charcoal can be used to create energy in the form of Briquettes. Briquetting is the process of compaction of residues into a product of higher density than the original raw materials. It is also known as densification. The use of fuel wood for cooking has health implications especially on women and children who are disproportionately exposed to the smoke apart from environmental effects. Women in rural areas frequently with young children carried on their back or staying around them, spend one to six hours each day cooking with fuel wood(Oladeji, 2015). In some areas, the exposure is even higher especially when the cooking is done in an unventilated place or where fuel wood is used for heating of rooms. Generally, biomass smoke contains a large number of pollutants which at varying concentrations pose substantial risk to human health. Agro waste is the most promising energy resource. The decreasing availability of fuel woods has necessitated that efforts be made towards efficient utilization of agricultural wastes. These wastes have acquired considerably importance as fuels for many purposes, for instance, domestic cooking and industrial heating. Some of these agricultural wastes for example, coconut shell, wood pulp and wood waste can be utilized directly as fuels. These waste can be processed in a form whereby they are well compacted and hardened in form that they burn for a longer a time. These processes as earlier stated is called briquetting and it is produced with aid of a briquetting machine.
Briquetting can help in expanding the use of biomass in energy production, since densification improves the volumetric calorific value of a fuel, reduces the cost of transport and can help in improving the fuel situation in rural areas(Hussein et al., 2012). Briquetting is one of several agglomeration techniques which are broadly characterized as densification technologies. Agglomeration of residues is done with the purpose of making them denser for their use in energy production(Wright et al., 2010). The idea of briquetting is to use materials that are not otherwise usable due to a lack of density, compressing them into a solid fuel of aconvenient shape that can be burnt like wood or charcoal(Adekoya, 2007).
The compaction of loose combustible material for fuel-making purposes was a technique used by mostcivilizations in the past(Wilaipon, 2007). Biomass densification, otherwise known as briquetting of agro-residueshas been practiced for many years in several countries. Briquettes were discovered to be an importantsource of energy during the First and Second World Wars for heat and electricity production, using simpletechnologies (Yadong and Henry, 2014). During this period, briquetting of sawdust and other waste materialsbecame widespread in many countries in Europe and America under the impact of fuel shortages. Screwextrusion briquetting technology was invented and developed in Japan in 1945. As of April 1969, there were 638plants in Japan(Grover and Mishra, 2011). The methods used were no more than simple baling or drying.Industrial methods of briquetting dated back to the second part of the 19th century.
Fuel briquettes are essentially a compressed block of organic waste materials used for domestic cooking andheating. The final end product of briquetting process is known as a briquette. Briquettes are made from raw materials that are compacted into a mould. Briquette could be made of different shapes and sizes depending on the mould. The appearance, burning characteristics of briquettes depend on the type of feedstock and the level of compactness and the mould used(El Saeidy, 2004; Wilaipon, 2007). But in general, briquettes have better physical properties and combustion rate than the initial waste. Production of briquette charcoal helps to ease the pressure on the forest reserve, there by solving the deforestation problem.
Briquettes have many numerous uses which include both domestic and small industrial cottage applications (Ahmed et al., 2008). They are often used as a development intervention to replace firewood, charcoal, or other solid fuels. This is because with the current fuel shortage and ever rising prices, consumers are looking for affordable alternative fuels and briquettes fill this gap as it can be used for domestic cooking and water heating, heating productive processes as in tobacco curing, firing ceramics and clay wares such as improved cook stoves, fuel for gasifiers to generate electricity and in powering boilers to generate steam.
1.2STATEMENT OF THE PROBLEM
Recycling of waste product is a very good source of income, but unfortunately it is not taken very seriously in this part of the world. Rural communities around Africa generate a lot of agricultural waste. These waste are not properly disposed of and this results in pollution of the atmosphere. In as much as these waste are not well utilised, deforestation is also another issue. Trees are felled for the sole purpose of getting firewood for domestic cooking and other heating purposes. The smoke from the burning of this wood is very hazardous to human health as continuous inhalation may result in lung problems and/or other health problems. It also results in the global change in climatic conditions.
Briquetting technology facilitates the utilization of these biomass residues as a source of renewable energy in contrast to simply disposing of these residues. The end result is creation of jobs for the ever increasing unemployed youths in the society as well as the creation of wealth. In the long run, it tends to promote the economic growth of the country.
1.3 AIM AND OBJECTIVES
1.3.1 AIM
The main aim of this study is to design and construct a standard screw type biomass briquetting machine capable of producing briquettes from biomass.
1.3.2 OBJECTIVES
The specific objectives are to:
i. Design a screw type briquetting machine capable of grinding, forming, setting and drying biomass into full briquettes.
ii. Fabricate a user friendly and cost effective briquette
iii. Collect sawdust from the local sawmill in the Effurun metropolis and groundnut shell from waste bins located around the school premises and use them to produce quality briquettes.
iv. Produce durable biomass briquettes within a very short time with little effort.
1.4 SIGNIFICANCE OF THE WORK
Due to the increasing demand of energy and the constant importation of fuel from other countries, the need for optimization of local energy sources should be given much effort. Production and utilization of alternative energy sources such as briquettes can be of help to address the rising energy demands of the country.
As of 2005, Nigeria has the highest rate of deforestation in the world according to the Food and Agriculture Organization of the United Nations (FAO). Deforestation is considered to be one of the contributing factors to global climate change. The effects of these climate change on Nigeria is very clearly seen as we experience heavy rainfall during the wet season and the scorching heat from the sun during the dry season. The thick fumes that is being emitted from the firewood stove is also another cause of global warming, these fumes no matter how little, when combined with other emitted fumes can deplete the ozone layer. This project is therefore important as one of its objectives is to help reduce or completely eradicate deforestation.
This work is also important for the bakery industry in Nigeria as regards the poor state of electricity in the country. Lots of bakery factories especially the foreign ones are closing up in the country due to this issue, but most of the available ones have resorted to the local oven. But as stated earlier, these ovens are not eco-friendly. The use briquettes as an energy source in these bakeries for their baking activities would greatly reduce smoke produced from the local ovens.
Production of briquettes in commercial quantity would also be a form of diversification of the economy, considering the fact that raw materials needed to produce these briquettes are very cheap and can easily be gotten from agricultural wastes majorly in host rural communities. If produced in a larger scale, it could also go as far as creating employment for the youths in the community, through production and sales of briquettes to companies and individuals both in rural and urban settlements.
1.5 SCOPE OF THE WORK
Briquettes produced by this machine will be sold at very low prices to the women selling roasted plantain and beans within the school premises in place of the charcoal they use. This could serve as a source of internally generated revenue for FUPRE.
Before now, biomass wastes are grinded in a grinding machine separately and then transferred manually to the briquetting machine where it is thoroughly mixed and compacted to give the strongly compacted briquettes. This research seeks to improve upon existing briquetting machines, as it proposes the fabrication of a grinder which will be attached to the hopper of the briquetting machine. The grinder will be attached to the hopper of the machine such that, as the biomass wastes is grinded in the grinder, it moves immediately to the briquetting machine by means of a conveyor system where it is compressed to give the strongly compacted briquettes.
The sawdust samples were collected from the local wood market in Effurun. And the groundnut shell samples were collected from waste bins around FUPRE school premises.
The machine can be used for large production of briquettes.
.