Design Your World

DESIGN, FABRICATION & PERFORMANCE STUDY OF PYROLYSIS REACTOR FOR LIQUID OIL PRODUCTION FROM PALM SHELL

2011-07-14T23:57:00.001+06:00

ABSTRACT

Pyrolysis is one of the most important thermo chemical energy conversion methods for renewable energy sources. In our university few project works has been done on pyrolysis. At first the stainless steel was selected for the construction of pyrolysis system and the palm shell was selected as feed material. Nitrogen gas was used to maintain the inert atmosphere in the reactor where the pyrolysis reaction takes place. The feedstock considered in this study was palm shell as it is available waste material in Bangladesh. Finally more liquid product was found (45% wt, which is maximum) at 550°C for size0.7-0.9cm.

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STUDY OF PHYSICAL PROPERTIES OF PYROLYSIS OIL

2011-07-14T23:55:00.002+06:00

ABSTRACT

A severe scarcity of energy both in the form of electrical energy and fuel is been uprising day by day along with the deterioration of the major natural resource of Bangladesh, natural gas. This lead to necessities of development on renewable energy rather than conventional sources of energy. It has been a great development in the field of biomass solid wastes. But attention has to be given in the recycling of organic solid wastes as it involves more hazard effects on the environment. Fixed bed pyrolysis system is more attractive among various thermo chemical conversion processes because of its higher conversion capability of solid wastes into liquid fuel. The conversion of organic solid tires wastes, which are found in abundance locally into pyrolytic oil by fixed-bed fire-tube heating reactor, has been taken into account in this study. Solid wastes of different sizes were pyrolized in an internally 30 cm height and 10 cm diameter fixed-bed fire-tube pyrolysis reactor. The reactor was heated by two electric heater coils of 1000Watt capacity each. Nitrogen was used as carrier gas which was preheated in the pre heater by a LP gas burner. The products were oil, char and gas. The parameters varied were temperature and feed size. These parameters were found to influence the product yields significantly. The maximum liquid yields were 65, 60 and 50wt% of motorcycle, bicycle and rickshaw tire wastes respectively all at 475⁰C and for tire feed size of 8cm X 1cm X 1cm.The pyrolytic oil obtained at these optimum process conditions were analyzed for their properties as an alternative fuel and compared with petroleum products.

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DESIGN AND CONSTRUCTION OF A RADIATION AND HEAT TRANSFER EQUIPMENT OF A NATURAL CONVECTION

2011-07-14T23:52:00.000+06:00

ABSTRACT

The main contents of this thesis includes the design and construction of a natural convection & radiation heat transfer equipment. With this equipment the heat transfer rate from a body by different modes can be found. The emissivity and the heat transfer coefficient of the body can also be determined. The total heat supplied to the element (heating element) is transferred in three modes. Heat transfer by conduction process can easily be measured. If the element in very low pressure or in a vacuum then the heat transfer by convection process become negligible and the total heat transfer by radiation process can be easily determined. And thus emissivity of the element can be determined. It was assume that the G.I sheet was mild steel. And the pressure vessel was made by G.I sheet. But when the vessel was making vacuum, air pressure squeezed the vessel and the equipment failed. Then it was necessary to analysis the case of failure. Moreover, the analysis of the G.I sheet by universal testing machine, it was seen that the properties (hardness, toughness, stress, etc...) of the sheet was not same the mild steel properties. Then necessary to analyze the case of tangential, compression & buckling where the equipment failed. As a result of analysis, buckling was the main cause of failure. In order to eliminate this failure, the properties of the sheet have to consider first.This work will help the beginner who wants to proceed in this field.

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EMISSION REDUCTION ESPECIALLY ODOR IN DIESEL ENGINE AT IDLING DURING ENGINE WARM UP

2011-07-14T23:47:00.000+06:00

ABSTRACT

DI diesel engine vehicles are becoming popular because of their friendly behavior to the environment as it emits lower CO₂. The main cause of it is that it consumes relatively smaller amount of fuel than a gasoline engine vehicle. But this increases both regulated and unregulated emissions like No_x, PM, exhaust odor and others. The regulated emissions are No_x, PM etc and unregulated emissions is the exhaust odor. Most diesel engine researches put their attention to reduce the regulated emissions. The attention of the authors is to reduce the unpleasant exhaust odor of DI diesel engines at idling. Among the various exhaust emission problems of DI diesel engine, odor is still a prominent emission problem. Reduction of exhaust odor can be done mainly in three ways. One of them is to optimize the engine parameters. But researches have been shown that the reduction of odor is not significant. The other is that the use of alternative fuels. Some alternative fuels can reduce the exhaust odor significantly but the cost is much higher than diesel fuel. The one is to use the catalyst system. The catalyst system hence cannot be applied at idling and at low temperature operation. The other is the absorption type system like water-washing system. By EGR, NOx reduces but PM emission increases, with which odorous emission increases. For this reason, EGR and Water- Washing System is used to improve emissions by reducing NOx & odor. Odorous emissions seems to be reduced using EGR, While reading is taken directly. This is due to the reason that EGR reduces the speed of exhaust gas. For this reason, indirect odor assessment is done, from which it is found that odor increases with the increase in EGR. The water washing system can be applied at idling and at low temperature operation. Since the emission of exhaust odor at idling at low temperature operation is higher than any other engine condition, and exhaust gas temperature is much lower at idling and low speed operation, the water washing system can be used. Some previous researches have shown that odor can be reduced greatly by washing the exhaust gas by water. Since there are no proper systems to reduce the exhaust odor at idling, this thesis report focuses on the water washing system. In the water washing system the exhaust was first passed through EGR system and then through water. Also, experiments were performed with EGR only and water washing only. From these experiments, it was found that odor reduced to 1point (a significant odor reduction) by using total setup (combination of EGR and water-washing). But individual components could not able to reduce the odor significantly.

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SEQUENCING FOR A BALANCED MIXED MODEL ASSEMBLY LINE: A CASE STUDY

2011-07-14T23:44:00.000+06:00

ABSTRACT

The mixed model assembly line has been taken into account. The balanced line has been studied for mixed model production scenario. Published mixed model situation is taken under study. Without proper sequencing for different demand situation line balancing problem study is not complete. To do so sequencing for the balanced mixed model assembly line is done. Simulation technique is widely used to solve the different complex problem in real world situation. So the simulation technique is applied to solve the problem and the simulation package AutoMod is used. The mixed model balanced line case study has been taken from published literature. The proper sequencing for the mixed model assembly line has been found. It is noticed that the completion time shows little higher than in the balanced mixed model assembly line. But it is better result than the original situation. This happened due to simulation as the previous solution has not taken some real world complexity.

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DESIGN, CONSTRUCTION AND PERFORMANCE TEST OF A TENSILE STRENGTH TESTING MACHINE FOR THREADS

2011-07-14T23:42:00.000+06:00

ABSTRACT

The title “Tensile strength Testing Machine for threads” implies the function of the machine. It is a machine used to measure the tensile strength and tenacity of threads. Our project was to design such a machine for small range capacity up to 150 N. Then the task was to construct the designed Machine by using indigenous materials. After the completion of the construction of the desired machine, it was necessary to test its performance. Hence various types of threads were tested by the machine and test results were compared.

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DETERMINATION OF FIN EFFICIENCY, FIN EFFECTIVENESS AND HEAT TRANSFER BY USING DIFFERENT COMBINATION OF FINS

2011-07-14T23:38:00.000+06:00

ABSTRACT

The main contents of this project and thesis include the design, construction, determination of fin efficiency, fin effectiveness and heat transfer by using different combination of fins, in practical field of mechanical and electrical engineering there are large number of engines and machines which work on the basis of heat energy transfer and requires cooling of the body. In many applications where water cooling or other means of cooling system may not be applied fin cooling may be the on of the options. Fins are extended surfaces of heat generating body that increase the rate of heat transfer and reject heat from the body to keep it cool for providing its operations efficiently. In this project work rectangular, triangular and inverse parabolic fin were considered. Heat transfer can be studied either by maintaining constant heat flux or constant temperature. This work was carried out at constant temperature to the base plate. This thesis compares the theoretical and experimental values of quality of heat transfer for all shape and position of the fins. It has been observed that the theoretical values are higher than their respective experimental values. The project work was carried out by placing the fin at vertical position.

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EMISSION CONTROL IN DI DIESEL ENGINE BY USING AQUEOUS SALT SOLUTION

2011-07-14T23:35:00.000+06:00

ABSTRACT

Diesel engines are a major source of urban air pollution. The engine exhaust gases contain oxides of nitrogen (Nitric oxide, NO and small amount of nitrogen-di-oxide, NO₂-collectively known as NOx), Carbon monoxide (CO) and particulate matter. Among this, NOx is a prominent exhaust emission problem. The heavy duty highway engine manufacturers can achieve substation emission reduction.The procedure for emission control are exhaust gas treatment, engine modification, fuel modification. The prime objective of this thesis is to reduction of emission especially NOx by fuel modification. Here fuel modification system include using aqueous salt solution. The engine was running at 50% constant load at variable speed. By this procedure formation of NOx is reduced, CO is increased, BSFC is reduced, exhaust temperature is reduced compared to neat diesel and also the efficiency of diesel engine is increased.

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EFFECT OF TEMPERATURE AND PRESSURE OF WATER WASHING SYSTEM ON EMISSIONS IN DI DIESEL ENGINES WITH SPECIAL EMPHASIS ON ODOR REDUCTION AT IDLING

2011-07-14T23:33:00.000+06:00

ABSTRACT

DI diesel engine is better than petrol engine in terms of fuel consumption and CO₂emission. But diesel engine has higher emissions like NOx, PM and exhaust odor. Among the various exhaust emission problems of DI diesel engine, odor is still a prominent exhaust emission problem. Reduction of exhaust odor can be done mainly in three ways. One of them is to optimize the engine parameters. The other is that the use of alternative fuels. The last one is exhaust gas after treatment. It is also of two types. One is to use the catalyst system. The catalyst system works only at high temperature condition, i.e. when the vehicle is in running condition (under load). The other is the non-catalytic type system like charcoal-absorption system, water-washing system, air-dilution system or others. Water washing system is a good option of odor reduction at idling. Last few years thesis report on odor reduction by water washing system showed that water washing system can reduce exhaust odor around 0.75 points. This thesis report focuses on the temperature and pressure effect of the water washing system. The experiment was performed with 20 liter and 112 liter water washing system in which cold water was used and the odor was reduced about 0.5 points for smaller one and more than 0.75 points for larger one. Some combination of water washing and air dilution systems were also used. It was found that odor was reduced about 1 points with the air dilution system combined with water washing system. It was also found that odor level was reduced about 1.25 points with the use of water washing system first then air dilution system. The combination of water washing system and air dilution system not only reduces odorous component but also reduces other emission components like CO, NOx, etc. It also increases eye irritation time which also indicates reduction in irritating components. It was found that CO, NOx, odor and eye irritation were reduced about 90%, 93%, 1.25 points and 96% respectively with the combination of these two systems.

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UTILIZATION OF SOLAR ENERGY FOR WATER PUMPING

2011-07-14T23:29:00.000+06:00

ABSTRACT

Many works have been carried out on this topic. In those works, the pump was used, and depending upon the power, demanded by the pump, a solar panel was used and then various characteristics were found out. The pump and solar panel were large in size. But this work deals with miniature pump and small solar panel, which stands for and can be used as a model one. This project primarily may be divided into two sections. At first a small centrifugal pump was designed on the basis of a low wattage solar panel, then it was characterized with the solar panel as well as the storage device, in this study lead acid cell is used. Thus it could be represented as a model pump. The characteristics of the pump was designed on the basis of solar panel power out put was observed and the characteristics curves were drawn.. In brief it may be said that this works deals with the characteristics of each of element in a solar photovoltaic water pump, i.e. it focuses on volume flow rate, head of water, hydraulic efficiency of the system, centrifugal pump operation analysis, its variation as a function of pumped rate flow and the rotational velocity. The rate of volume flow and the head of water were also observed as a function of rotation, at different day hours.

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DESIGN, FABRICATION AND PERFORMANCE STUDY OF AN INTERNALLY HEATED FIXED-BED CONTINUOUS PYROLYSIS SYSTEM

2011-07-14T23:23:00.000+06:00

ABSTRACT

In this study one internally heated fixed-bed continuous pyrolysis system has been designed and fabricated. Waste material in the form of car scrap tire was pyrolysed in an internally heated fixed bed pyrolysis reactor. The reactor was 10cm in diameter and 30cm in height .The feed sizes were 12cm´1cm´1cm,10cm´1cm´1cm, 8cm´1cm´1cm, 8cm´1cm´0.5cm and 8cm´0.5cm´0.5cm. The reactor was heated by means of an electric heater and L P gas burner preheated the purging nitrogen gas. The products were liquid, char and gas. The liquid and char products were collected separately while the gas was flared into atmosphere. A gravity feed type reactor feeder was used to feed the reactor and the solid char was pushed out by compressed air supplied by an air compressor. The liquid product was collected in a series of ice-cooled liquid collectors. The maximum liquid yield was 48% for feed size of 8cm´0.5cm´0.5cm and char yield was 45% for feed size of 12cm´1cm´1cm for car scrap tire. The condensed pyrolytic oils were analyzed for their physical properties. The heating values of the liquid and char are 41,500 kJ/kg and 35,000 kJ/kg respectively. The result of the analysis shows that the oils are favorable high heating value. From this study it is found that the solid waste tyre may be a potential source of liquid hydrocarbon fuels.

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FIXED BED PYROLYSIS SYSTEM FOR LIQUID OIL FROM THE HAY OF CATKIN

2011-07-14T23:18:00.000+06:00

ABSTRACT

With rapidly increasing energy costs, the necessity of finding new sources of energy is becoming more urgent than before. As energy sources are limited, this project may be considered as a promising option. The hay of catkin is taken as a potential resource for the project work on fixed bed pyrolysis.

In this research study, the feedstock(biomass) is taken into the fixed bed reactor of stainless steel of 7.62cm diameter and 30 cm length and is heated to 350 ^OC-550 ^OC. This high temperature converts the feedstock into gaseous vapor and solid char. Liquefied petroleum gas (LPG) is flown through the reactor from a cylinder at a controlled rate dispose of the gaseous vapor to collector through a condenser. The condenser helps the vapor to be converted into liquid product. The liquid product is collected and the non-condensable gas is flared of.

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DETERMINATION OF FLOW CHARACTARISTICS OF AIR IN A SMOOTH PIPE

2011-07-14T23:15:00.000+06:00

ABSTRACT

We determined various velocity profiles for different percentage of valve opening. From those we saw that for 10% valve opening the velocity profile became sharp. Because after entering air to the pipe for wall shear stress, thicker sub layer, low velocity gradient and friction loss it became sharp. Within (10-50)% of valve opening laminar region may exist. After 60% valve opening the profile became fuller or blunt. Because of high velocity gradient, thinner sub layer it became blunt. Within (60-100)% of valve opening the turbulent region may exist. This phenomenon was seen accumulating those profiles. For determining friction factor we found out average velocity from individual velocity profile. We calculated corresponding Reynolds number on the basis of average velocity. Within certain length we determined friction factor on the basis of pressure drop, average velocity, diameter and length. Plotting those data we obtained friction factor Vs Reynolds number graph. From graph we see that as Reynolds number is increased the friction factor decreases as long as the flow remains laminar. At transition friction factor increases sharply. In the turbulent flow regime, the friction factor decreases gradually and finally levels out at a constant value for large Reynolds number. Finally we obtained % of valve opening Vs Reynolds number graph. From it we see that as % of valve opening increases the average velocity increases, then Reynolds number increases and finally levels out at a constant value for large Reynolds number.

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STUDY OF PYROLYTIC BEHAVIOR OF SCRAP TIRES AVAILABLE IN BANGLADESH

2011-07-14T23:11:00.000+06:00

ABSTRACT

Among various thermo chemical conversion methods, pyrolysis has been considered as the most efficient way of producing liquid fuel from organic solid wastes. To look for a definite source of renewable energy as a fuel from organic solid wastes, a project work on the study of pyrolytic behavior of solid wastes including scrap tire has been carried out. Pyrolysis kinetics of scrap tires of bicycle, motor and truck have been investigated thermo gravimetrically under nitrogen atmosphere at heating rates of 10 and 60°C/min and temperature range of 100-800°C. The results show that the initial reaction temperature regions are 130~140°C for bicycle, 140~160°C for motor cycle, 130~150°C for truck tire. The tires exhibit similar behaviors that the initial reaction temperature decreases, but reaction range and reaction rate increase when heating rate is increased. The DTG peaks shifted to higher temperature regions for higher heating rates. Among the three samples the value of total weight loss is higher for truck tire and lower for bicycle tire. The faster degradation occurs for truck tire and slower for motor cycle tire. The overall rate equation for all tire wastes can be modeled satisfactorily by a simple equation from which the kinetic parameters such as the activation energy (E), the frequency factor (A) and the reaction rate (K) can be determined. For different heating rates the average activation energy, E = 70.68kJ/mol for bicycle tire, 76.12kJ/mol for motor cycle tire and 67.00kJ/mol for truck tire and the average frequency factor A = 7.32×10⁶ min^-1 for bicycle, 32.38×10⁶ min^-1 for motor cycle and 11.82×10⁷ min^-1 for truck tire. Generally the value of activation energy increases with increasing conversion factor up to its certain value and then decreases adversely. Finally an internally heated, fixed-bed pyrolysis system was used to produce fuel based liquids from scrap tire.The product yields were liquid 55%, char 30%. The heat value of liquid was 39.456kJ/kg and char was 25.45kJ/kg. DTA curves shows that the degradation reaction is endothermic reaction.

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PREPARATION OF BIO DIESEL FROM COTTON SEED OIL AND PERFORMANCE & EMISSION STUDY OF A DIESEL ENGINE USING DIESEL- BIO DIESEL BLENDS

2011-07-14T23:09:00.000+06:00

ABSTRACT

Biodiesel is known as “the mono alkyl esters of long chain fatty acids derived from renewable lipid feedstock, such as vegetable oils or animal fats, for use in compression ignition (diesel) engines.” It is an oxygenated, free from sulfur & carcinogenic benzene, non-toxic, biodegradable and echo friendly alternative fuel. One of the major characteristics of bio-diesel, which directs its feasibility for using, as an alternative of conventional diesel fuels is that its use does not require any significant modification of diesel engine. However, due to its different properties like higher viscosity, lower heating value, lower volatility, excess oxygen content, and higher flash point; bio-diesel may cause some change in engine performance and emissions including lower power and higher oxides of the nitrogen. This report is divided into two phases. In the first phase different parameters for optimization of biodiesel production was investigated. Biodiesel was made by transesterification. Cotton seed oil is selected for biodiesel production. The results showed that with the variation of catalyst, methanol or ethanol, variation of biodiesel production was realized. However, the optimum condition for biodiesel production is suggested in the report. It is found that for 0.5% Sodium hydroxide and 20% methanol bio-diesel production was maximum. In the second phase of the investigation, the performance study of a diesel engine with diesel – biodiesel blends were carried out. The results showed that when compared with neat diesel fuel, biodiesel gives almost similar thermal efficiency, lower carbon monoxide (CO) while slightly higher nitrogen oxide (NOx) emission is experienced.

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DEVELOPMENT OF THE EXISTING SQUARE DUCT WITH PROBE TRAVERSING MECHANISM AND STUDY THE CHARACTERISTICS OF VELOCITY FIELD

2011-07-14T23:05:00.000+06:00

ABSTRACT

The existing square duct with two- dimensional probe traversing mechanism is modified care is taken to ensure that the duct is straight and horizontally level. A new pitot tube is fabricated.It is then calibrated with a standard pitot tube to obtain the true values of the values measured by the fabricated one. The fabricated Pitot tube was calibrated in order to obtain standard value with a standard pitot tube.

1. Velocity distribution: The velocity is higher at the center of the duct and the velocity decreases towards the wall. Z= ±10 producing saddle like shape indicating influence of secondary flow. The velocity profiles near the center appear to more parabolic at higher Reynolds number than those at lower Reynolds number the jig jag shape of the profiles because of fluctuation in supply voltage as well as error in taking readings.

2. Universal velocity distribution: Universal velocity distribution curve is drawn with uand z. For Reynolds no 10.94xand 6.07x, we found linear equations u=25.6+8.45zand u=26.02+0.03 z respectively. The universal velocity distribution curves changes with the change in Reynolds number .

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STUDY AND COST VERIFICATION OF THE VARIOUS SYSTEMS OF A CNG AUTO RICKSHAW AND SIMULATION WITH STRESS ANALYSIS OF ITS CHASSIS

2011-07-14T23:00:00.000+06:00

ABSTRACT

This project describes the necessity of CNG auto rickshaw and shows the production and assembly costs of the chassis as well as the production and assembly costs of a CNG auto rickshaw, the simulation of the chassis of the auto rickshaw, two dimensional (2D) drawings of various parts of the chassis, three dimensional (3D) drawings of the chassis and the stress analysis of the main bar of the chassis. The prices and costs are collected from the shops of various local markets, wholesale dealers, importers and Bangladesh Industrial Technical Assistance Centre (BITAC), Dhaka. The two dimensional (2D) drawings of various parts of the chassis and three dimensional (3D) drawings and simulation of the chassis have done by the “Auto CAD” (version 2006) software and the stress analysis of the main bar of the chassis has done by the “Solid Works” (version 2004) software. The cost verification showed that the cost of the CNG auto rickshaw manufactured with the help of the proposed simulation is much more less than the cost of the imported auto rickshaw and the proposed simulation is applicable for our countrywide transportation situation.

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DESIGN, FABRICATION AND PERFORMANCE OF A TYPICAL GENEVA STOP

2011-07-14T22:58:00.000+06:00

ABSTRACT

This project entitled “Design, Fabrication And Performance Of A Typical Geneva Stop” implies the function of the GENEVA MECHANISM. The Geneva Stop has been designed and fabricated at the RUET laboratories of the DEPARTMENT of Mechanical Engineering, with locally available materials e.g. wood. This project can be used to demonstrate the function of “Geneva Mechanism”. This widely used in different industries e.g. in beverage companies etc. Velocity and acceleration diagram has been discussed in this project. Some velocity & acceleration components have been found from the velocity & acceleration diagram. Some characteristics curves have been drawn from the velocity & acceleration components of the velocity and acceleration diagram.

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STUDY, ANALYSIS & DESIGN OF A LP GAS REGULATOR

2011-07-13T23:54:00.003+06:00

ABSTRACT

Bangladesh is rich in resources of natural gas. Liquefied petroleum gas is also known as LP gas. Liquefied petroleum gas is used in our country both in home and industrial appliances. LP gas regulator is an important mechanical device which is installed at the opening of the LP gas cylinder. It function is to control the outlet pressure of the gas. It also helps to maintain the discharge constant. In this project physical and analytical study on the LP gas regulator is done. A LP gas regulator is also designed which is modified and simple from the conventional LP gas regulator. This design may be helpful to produce the LP gas regulator in Bangladesh.

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STUDY OF THE EFFECT OF WELDING ON STRESS, STRAIN AND HARDNESS OF MILD STEEL

2011-07-13T23:51:00.002+06:00

ABSTRACT

Welding is the process of uniting together of two pieces of similar metals or alloys by fusion. Intense heat is applied close to the parts to be welded, keeping the two pieces of metals together, so as to form a molten puddle at the place of weld which during cooling, unite together by metallurgical atom to atom bond. As a general rule a filler rod or an electrode is used to fill up the weld and to form the puddle Metals play a major role in the industrial and everyday life of human beings. We see hundreds of metal objects and parts which find engineering applications. Mild steel is used in transportation, industrial-structural frame work, engine parts, decorative features, doors, window frames, fittings, conductors, heat exchanger parts, packaging and different alloys of mild steel is vastly used in trucks, trains, buses and aero planes. Mild steel is used for making valves, gears, crank shafts, connecting rods, railway axles, camshafts, shits and strips for fan blades, forgings, drag lines etc. Thus it is found that the selected materials have vast uses. To make above mechanical parts welding is essential. For these reasons it is necessary to know the mechanical properties of the metal that means stress, strain & hardness. In this thesis work the mechanical properties of the selected material are analyzed and studied with the relationship of these mechanical properties before and after welding. It was seen that the stress of mild steel bar decreased after welding for any cross-section. The stress decreased due to heat treatment of metal. After welding the hardness of the mild steel increased because of rapid cooling. During experiment it was seen that the proportional limit of the specimens decreased due to effect of welding. It was also observed that the strength of the specimens decreased which means the yield strength & ultimate strength decreased but hardness increased because, after welding when it cooled the molecules of the specimen became compact Thus the property of the specimen has changed due to welding effect. In order to test stress, strain and hardness number, first it was made the specimens in the machine shop. Then the stress, strain and hardness number were tested in the metrology lab. Again the virgin specimens were made and these specimens were cut in the middle position and welded. Then the stress, strain and hardness number were tested. The data was compared with the virgin (before welding) specimen. The welding causes a percent of decrease in the yield stress & ultimate stress and increased the hardness number of the specimens.

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DESIGN,FABRICATION & PERFORMANCE STUDY OF A BATCH-TYPE FIXED-BED FIRE-TUBE HEATING PYROLYSIS SYSTEM FOR PRODUCTION OF LIQUID OIL FROM BICYCLY/RICKSHAW & TRUCK SCRAP TIRES

2011-07-13T20:06:00.003+06:00

ABSTRACT

In this study a batch-type fixed-bed fire-tube heating pyrolysis system has been designed and fabricated to produce liquid oil from scrap tires. Waste materials in the form of bicycle/rickshaw and truck scrap tire were pyrolysed in an internally heated batch-type fixed-bed fire-tube heating reactor system. The solid waste tires in pieces form was pyrolyzed in a 10 cm diameter and 27cm height reactor. The feed sizes were 10cmxO.5cmxO.25cm to 25cmx2cmx0.25cm. The reactor was heated by means of uniformly distributed electric coils of total capacity 2800wt and LPG burner preheated the purging N2 gas. The products were oils, char and gas. The liquid and char products were collected separately while the gas was flared into atmosphere. The product liquid was collected in a series of ice-cooled liquid collector. The maximum liquid and char yield were 52% and 35% for bicycle/rickshaw tire and 60% and 23% for truck tire for feed size of 10cmxO.5cmxO.25cm and 10cmx2cmxlcm respectively. The condensed pyrolytic oils were analyzed for their physical properties. The fuel properties compared were physical properties and calorific value. The heat values of the liquids of truck tire and bicycle/rickshaw are 40733 kJ/Kg and 41000 respectively. The results of the analysis showed that the oils were favorable viscosity and high heat value. From this study it is found that the pyrolysis of solid tire wastes may be a potential source of liquid hydrocarbon fuels.

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EFFECT OF TEMPERATURE AND PRESSURE OF CHARCOAL ADSORPTION SYSTEM ON EMISSIONS WITH SPECIAL EMPHASIS ON EXHAUST ODOR IN A DI DIESEL ENGINE AT IDLING

2011-07-13T19:55:00.004+06:00

ABSTRACT

Fuel consumption in petrol engines is about 20-30% higher than that of diesel engines that causes high CO₂ emission as well as greater pollution of environment. DI diesel engines have the lowest fuel consumption as well as CO₂ emissions. So, DI diesel engine vehicles are becoming popular day by day. But this increases both regulated and unregulated emissions like NO_X, PM, exhaust odor and others. Among the various exhaust emission problems of DI diesel engine, odor is still a prominent exhaust emission problem. Reduction of exhaust odor can be done mainly in three ways. One of them is to optimize the engine parameters. But researches have shown that the reduction of odor is not significant. The other is that the use of alternative fuels. Some alternatives fuels can reduce the exhaust odor significantly but the cost is must higher than diesel fuel. The last one is exhaust gas after treatment. It is also of two types. One is to use the catalyst system. The catalyst system works only at high temperature condition i.e. when the vehicle is in running condition (under load). This system hence can not be applied at idling and at low temperature operation. The other is the non-catalytic system like adsorption type system, water washing system, air dilution system and others. Since the exhaust emission and odor at idling and low temperature operation is higher than any other engine condition and the exhaust gas temperature is much lower at idling and low speed operations, the charcoal adsorption system can be used. Some previous researches have showed that several organic compounds (aldehyde, organic acids and oxygenated compounds) are important odorous groups in exhaust and they correlate well with exhaust odor. Odor can be reduced greatly by adsorbing these odorous components by charcoal adsorption system. Last few years thesis report on odor reduction by charcoal-adsorption system showed that charcoal-adsorption system can reduce exhaust odor around 0.75 points. This thesis report focuses on the temperature and pressure effect of charcoal adsorption system. The experiment was performed first with a 1.5 ft long double chamber adsorption system and the odor is reduced about 0.25 points. It is clear that if a larger cold charcoal adsorption system (5 ft) is used the odor could be reduced far more, even more than 0.75 points. The double chamber adsorption system in which temperature was controlled can also reduce other emissions significantly. CO emissions also can be reduced with this system. Some combination of charcoal adsorption and air dilution systems were also used. These systems reduced odor level from 3.75 to 2.25. Other emissions (NOx, CO) are also significantly reduced.

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DESIGN CONSTRUCTION AND PERFORMANCE TEST OF A HYDRAULIC TEST RIG FOR PET BOTTLE

2011-07-13T19:49:00.002+06:00

ABSTRACT

Design and construction of pressure testing rig are performed to test the hydrostatic pressure of PET bottles of particular sizes of 1 liter and 1/2 liter. PET bottles are excellent barrier materials and are widely used for soft drinks and also for transmitting it from one place to another at high pressure. As a result most important or vital property of PET Bottle which has to be tested is its resistance to internal pressure developed by the form of carbon-dioxides. The main problem in the test is to seal the open end of the bottle with adapter. The hydraulic jack is used in our project as a pump. The goal of the present work is to study the pressure withstanding capacity of PET bottles and picked up the circumferential stress. It is determined by the rupture pressure of PET bottles.

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DESIGN, CONSTRUCTION AND PERFORMANCE TEST OF A SINGLE AXIS SOLAR TRACKING SYSTEM USING WIPER MOTOR FOR PHOTOVOLTAIC SOLAR PANEL

2011-07-13T19:40:00.001+06:00

ABSTRACT

Track means path and tracking means control an object in a defined path or in a special movement. The work is done on a single axis Solar Photovoltaic (PV) tracking system with Complementary Metal Oxides (CMOS) logic circuits. The controlling motion for PV panel has been provided by discrete motion of the motor. CMOS Integrated Circuits (ICs) with timer and relays are used in the control circuits, which generate pulses for rotation of the motor drive. For tracking of predetermined position (offline) of the panel, a disc is attached with it and indexed with contact points according to design. A micro-switch is used to switch the control circuit for rotation of the disc at required time interval to track the Sun's position. When compared with the conventional tracking systems like stepper motors with driver circuits and program with computer systems, this tracking system has been found independent of computer system which makes it for stand alone application. This tracking system is low cost because it contains low cost CMOS chips. Finally this system is simple and high efficient for trapping the Sun's incident energy. The power developed by tracking system is greater than without tracking system.

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ANALYSIS OF A NEGATIVELY BUOYANT JET

2011-06-28T01:15:00.002+06:00

Proceedings of the
International Conference on Mechanical Engineering 2009
(ICME2009) 26- 28 December 2009, Dhaka, Bangladesh

ICME09-FM-36

ANALYSIS OF A NEGATIVELY BUOYANT JET

Chandan Kumar, D. Das and M.M. Razzaque
Department of Mechanical Engineering, Bangladesh University of Engineering and Technology (BUET),
Dhaka, Bangladesh.

ABSTRACT

The behavior of plane fountains, resulting from the injection of dense fluid (water) upwards into a large container of homogeneous fluid of lower density (air), is investigated. In this study we experimentally examine the behavior of fountains for different Froude and Reynolds numbers. The fountain inlet flow rate and nozzle diameter of the inlet fluid is varied to cover a wide range of Reynolds and Froude numbers. Fountain behavior is observed by changing the inclination angle of the fountain for different nozzle diameter and flow rate. We found that the penetration height greatly depends on Froude number. We develop an empirical correlation of the non-dimensional fountain height with Froude number (H/r =1.452Fr1.94). But well defined by both Reynolds and Froude number. Finally we also develop an empirical correlation of the non-dimensional fountain height Reynolds and Froude number (H/r= Re-0.72Fr2.26) by numerical regression. The result are compared with previous numerical and experimental results and found consistent.

Keywords: Buoyant Jet, Negatively Buoyant Jet, Fountain, Positively Buoyant Jet, Reynolds Number.

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