LAKSHMI AMMAL POLYTECHNIC COLLEGEDESIGN AND FABRICATION OF AQUA SILENCER PROJECT REPORT SUBMITTED BY SL.NO NAME REG NO 1. PETER.V 14209893 2. POOL PANDIAN.K 14209894 3. RAJENENDRA BOOPATHY.R 14209896 4. RAMRAJ.T 14209897 5. SARATH KUMAR.P 14209898 IN PARTIAL FULLFILLMENT FOR THE AWARD OF THE DIPLOMA IN AUTOMOBILE ENGINEERING LAKSHMI AMMAL POLYTECHNIC COLLEGE K.R.NAGAR-628503 DIRECTORATE OF TECHNICAL EDUCATION,CHENNAI APRIL-2016 DEPARTMENT OF AUTOMOBILE ENGINEERING 2015-2016 CERTIFICATE THIS IS TO CERTIFY THAT THE PROJECT WORK ENTITLED DESIGN AND FABRICATION OF AQUA SILENCER Submitted in partial fulfillment for the award of diploma in AUTOMOBILE ENGINEERING of the Board of Technical Education, Tamilnadu under semester system is a Bonafide Record of the workdone. By GUIDE REG.NO HEAD OF DEPARTMENT In the year 2015-2016 PRINCIPAL Submitted For Board Practical Examinations held On INTERNAL EXAMINER EXTERNAL EXAMINER ACKNOWLODGEMENT ACKNOWLEDGEMENT At this pleasing moment of having successfully completed our project. We wish to covey our sincere thanks and gratitude to the management of our College for provided all the facilities to us. We would like to expresss our sincere thanks to our principal Prof.M.KUPPUSAMY,M.E., for forwarding us to do our project and offering adequate duration in completing our project. We are also grateful to the head of the department V.SUBRAMANIAN, M.E.,For his constructive suggestion & encouragement during our project. With deep sense of gratitude ,we extend our earnest &sincere thanks to our guide S.SIVA KUMAR,B.E., AUTOMOBILE for his kind guidance and encouragement during this project. We also express our thanks to the TEACHING AND NON TEACHING staffs Of AUTOMONBILE ENGINEERING DEPARTMENT. PREFACE . Since project work is clear to .PREFACE In order to cover the vast syllabus within the shortest possible time and also to take the study not to be superficial and to have share knowledge of AUTOMOTIVE TECHNOLOGY Project work is done. “The Department of Technical Education of TAMIL NADU” as taken up Different project in each branch of the studies. Our doubts and also the dial to young ideas. Under the scheme the “sixth semester automobile engineering studies” of this polytechnic carried out useful project namely DESIGN AND FABRICATION OF AQUA SILENCER . CONTENTS CONTENTS CHAPTER NO TITLE SYNOPSIS LIST OF FIGURES 1 2 3 4 4.1 4.2 5 6 7 8 9 Introduction Literature review Description of equipments Design and drawing Machine components Overall diagram Working principle Advantages and Disadvantage Applications List of materials Conclusion Bibiliography Photography LIST OF FIGURES LIST OF FIGURES Figure Number 1 Title Over all diagram SYNOPSIS . . SYNOPSIS This project is an attempt to reduce the toxic content of diesel exhaust. chemicals processing industries. which demands the need for diesel power packs. . This system can be safely used for diesel power packs which could be used in inflammable atmospheres. such as refineries. before it is emitted to the atmosphere. open cost mines and other confined areas. CHAPTER .1 INTRODUCTION . which demands the need for diesel power packs. . such as refineries. which erodes the purity of our environment everyday. inmost developed countries like USA and EUROPE. open cost mines and other confined areas.CHAPTER . Considering the available fuel resources and the present technological development. In spite. the consumption of fuel is an index for finding out the economic strength of any country.1 INTRODUCTION Diesel engines are playing a vital role in Road and sea transport. In general. chemicals processing industries. Agriculture. we cannot ignore the harmful effects of the large mass of the burnt gases. This system can be safely used for diesel power packs which could be used in inflammable atmospheres. the diesel power packs find the ever increasing applications and demand. mining and many other industries. This project is an attempt to reduce the toxic content of diesel exhaust. While. before it is emitted to the atmosphere. Diesel fuel is evidently indispensable. It is especially so. constant research is going on to reduce the toxic content of diesel exhaust. which otherwise will be hazardous and prone to accidents. The provision of suitable baffles in the scrubber tank aids the turbulence so that. The bell – mouth solution. where as in petrol engines the CO content may be as high as 10 percent. while most of the oxides of nitrogen in the exhaust are rendered non – toxic. here the temperature of the gases are reduced. thorough scrubbing takes place. The highly dangerous carbon monoxide is not such a menace in diesel exhaust.For achieving this toxic gases are to be reduced to acceptable limits before they are emitted out of this atmosphere. as it does not exceed 0. while reducing the back pressure. . REDUCTION OF ABNOXIOUS EXHAUST PARTICULATES The principle involved is by bubbling the exhaust gas through the scrubber tank containing an alkaline solution. A lime stone container in the scrubber tank reduces the considerable percentage of sulphur – di – oxide presents in the exhaust.2 percent by volume. The difference is evaluated and effective control is initiated. These sampling points enable us to measure the exhaust gas content before and after scrubbing. . provisions are made to take samples between engine outlet and scrubber inlet and after the scrubber outlet before the gases are let-out to the atmosphere.MEASUREMENT OF EXHAUST GAS CONTENT ANALYSIS AND CONTROL For measuring the contents of the exhaust gas. The samples are analyzed by using an orsat apparatus of the system. . CHAPTER-2 LITERATUR E SURVEY . Number of cylinders 5. The pressure of the exhaust gas depends upon so many factors viz. In order to maintain the . Engine speed 4. The length of the exhaust gas flow path. Magnitude of valve overlap 3.CHAPTER-2 LITERATURE SURVEY DESIGN CONSIDERATIONS EXHAUST OF BACK PRESSURE AND ENGINE PERFORMANCE The exhaust gas contains carbon – di – oxide. The design of exhaust gas manifold is very important in case of high sped diesel engines. etc. The design of exhaust gas manifold 2. carbon monoxide and other oxides of nitrogen. At full load. the temperature of the exhaust gas will lie anywhere between 500°c to 700°c. sulphur – di – oxide. 1. if it is allowed to exceed the predetermined level. so that the engine can be kept at the optimum operating level. The back pressure. . This is absolutely essential in order to maintain the back pressure with in safe limits. the gases which come out of the cylinder flows very smoothly. the exhaust gas manifold is designed so that. the primary consideration when introducing any modification in exhaust system does not and shall not increase the back pressure which drastically affect the performance characteristics of an engine. before it is let out to the atmosphere. the effort on the part of the piston for scavenge is considerably increased and so power is lost in performing the above so.exhaust gas pressure with in required limits. the speed of the engine is affected for a given specific fuels consumption rate and so the combustion characteristics of an engine is affected. To be more precise. the combustion is not proper and complete which results in the increased impurities or unburnt gases. Considering the factors to the specific application of this project. introductions of a scrubber tank will definitely increase the back pressure. it is implied that the introduction of any system reduce the toxic property of the exhaust gas. In the scrubber tank the followings are the factors which will contribute to the increase of back pressure. So the increase of back pressure is inevitable unless the increase in magnitude compensated in the design of the component itself.As a net result. So by introducing any component in the system the flow path length and the resistance to flow are indirectly increased. . So. shall not result in any effects in the opposite direction. This principle against the purpose of introducing any system whose sole object is reducing the very toxic property of the exhaust gas. The gas has to push the water. the outlet from the engine shall be kept below the water level in the scrubber tank for that the gas will pass through the water. This may create chances to increase the backpressure. pressure.. which is filled in the scrubber tank. which are provided to deflect the exhaust gases. some of the water particles which comes in contact. In any case. also offers resistance to the flow and intern increases the back. BACK PRESSURE EXERTED BY EVAPORATED WATER PARTICLES Due to the high temperature. readily changes its phase from liquid state to gaseous state i. steam which increases the net mass of the . in order to bubble through the water in the scrubber tank. The gas has no to push the water. BACK PESSUE EXERTED BY BAFFLES The baffles.BACK PRESSURE EXERTED BY WATER IN THE SCRUBBER Exhaust gas has to pass through the water. the exhaust gas is let out from the engine.e. in order to bubble through the water. It is evidently affects the flow of resistance and hence the combustion characteristics of the engine will finally contributes the increased toxic ingredients of the exhaust gas. are originally intended to reduce the toxic ingredients of the exhaust gas through chemical reaction.exhaust gas flow per unit time. contributes to the increase of backpressure. BACK PRESSURE EXERTED BY EXHAUST FLOW PATH LENGTH Because of the introduction of the scrubber. The resultant may increase the backpressure. against the original intention. the net length of the exhaust gas flow path also is increased which is again. The limestone’s. . BACK PRESSURE EXERTED BY LIME STONE CONTAINER The lime stone container is used to stores the lime stone and offers a definite and increased resistance to flow which again. Basically. . the elimination of a separate silencer will half way solve the problem. while all the above factors contribute for the increased backpressure of the system. This could be in principle. accomplished by so many ways. The process itself contributes to the reduction of pressure of the whole system. which is eliminated totally.So. the system has to be so designed or constructed to reduce the above increase of pressure to its original intended value or original designed value of the engine exhaust system. EFFECT OF BELL – MOUTH IN SCRUBBER TANK The introduction of the bell-mouth assembly facilitates the exhaust gas to expand many times by volume gradually before it is coming in contact with the water in the scrubber tank. because the scrubber tank itself will act as a silencer and hence the resistance offered by a separate silencer. but enhances the performance of the system as a whole. The shape and length of the pipe is decided according to the space availability to keep the flow resistance to a minimum. which is also the inlet diameter of the scrubber tank. it is absolutely essential to make a provision for the measurement of backpressure in the system. OUTLET PIPE FROM THE ENGINE (OR) INLET TO THE SCRUBBER TANK The outlet pipe from the engine was connected to the scrubber tank. that it can be controls the same if necessary occurs. This ensures not only the safety.While designing. Hence. The nominal bore of the pipe is 50mm. the system have to be very careful so as not to increase the backpressure unduly which will affect the performance of the engine in the negative direction and so the constant of the exhaust gases. SCRUBBER – TANK ASSEMBLY . so. with leak – proof. 2. which are to be accommodated inside. Bell – Mouth. DESIGN CONSIDERATIONS The tank is 5 liters capacity keeping in view the size of Bell-mouth and lime stone container. 1. 3. The maximum water content of the . Designation ST 42S.8N/mm2 [8Kg/Cm2]. Lime stone container 4. The tank is fabricated using Electric Arc Welding process to withstand a maximum pressure of 0.The scrubber tank is fabricated in three stages and it contains the following sub assemblies. Level plug – Drain Assembly. Tank. TANK FABRICATION The tank is made of standard steel plates of 3mm thickness of quality structional steel conforming to BIS: 226. This accounts for a total enlargement of more than 2½ times. Bell – Mouth Fabrication The bell – mouth is made of standard steel plates of 3mm thickness of quality structural steel conforming to BIS: 226. as to reduce the backpressure and temperature. the overall flow path of ½ times. The baffles also prevent entry of water into the stone container to a considerable extent. which is originally available. the area is about 22500mm2. The areas at the inlet portion are about 9025mm 2. Suitable baffles are provided which will encourage through scrubbing of the exhaust gas. the area. which is originally . DESIGN CONSIDERATION The bell – mouth is provided to expand the exhaust gas so.tank is about 3 liters. the area. corresponding to 115mm of water level from the bottom of the scrubber tank. Designation ST 42S. At the end where the expansion is complete. The greater amount of expansion and lesser-required water displacement ensures minimum backpressure during the bubbling of exhaust gas. using Electric Arc welding. Lime stone Container Fabrication The container is made of standard steel plates.available. The back pressure can be further reduced by introducing a suitable space between the bell – mouth and tank top flange without necessitating the reduction of water level in the scrubber tank. The water column inside the bell – mouth is 25 – 30mm maximum. Designation ST 42S – Mild steel Plates. DESIGN CONSIDERATIONS . The overall flow path of the bell – mouth is more than 330mm. which has 2mm thickness of quality steel plates conforming to BIS: 226. This accounts for a maximum amount water displacement under peak load conditions. because the effective area is more than 1. there by increasing velocity and reduces pressure before it is let into the outlet pipe. Lime stones are to be only below the outlet portion.) limestone. This facilitates the easy flow of exhaust gas. The capacity of the container is less than 2 liters.The stone container is designs to accommodate 35 – 40mm cross sectional area (approx. which is above the top plate of the tank. The conical shape at the top ensures gradual reduction of flow area. the lime stone container can be easily visible for the cleaning and changing the lime stone becomes very simple. But the diameter of the holes is less than the lime stone which is filled.5 times the area at the inlet of bell – mouth. By separating the out let portion. to prevent the lime stones from falling into the tank. LEVEL PLUG CUM DRAIN FABRICATION . Suitable holes are provided at the circular sidewalls of the container. a tee welded at the bottom of the level pipe to accommodate the drain plug. which shows the level of water in the scrubber tank. DESIGN CONSIDERATION The level plug is designed to maintain a level of 115mm inside the tank. The surface is rough ground in order to have better finish.7mm nominal bore pipes fittings and conforming to BIS: 1369 where. During the evaporation period this will be useful to maintain the level of water. Instead of providing a separate drain plug. which is welded to the bottom of the tank. The whole assembly can be unscrewed and taken out of the tank for periodic maintenance and repair by unscrewing the thread. which is fastening it to the boss. .The level plug cum drain is fabricated using 12. Water level indicator is fixed in the tee joint. fabricated using electric arc welding. The flange at the end is to suit the flange on the outlet of the lime stone container. which is also the diameter of the inlet pipe. which are conforming to BIS 1369. The shape and length of the pipe are to keep the flow resistance to a minimum. The nominal bore of the pipe is 60mm. .OUTLET PIPE FROM THE SCUBBER TANK The outlet pipe from the scrubber tank is fabricated using standard medium duty pipes. CHAPTER-3 DESCRIPTIO N OF EQUIPMEN T . Risk of trackless vehicles entering inadequately ventilated areas. 3. 2.CHAPTER-3 DESCRIPTION OF EQUIPMENT The problems that arise from the Diesel utilization in inflammable environment may be listed as follows: 1. This section examines the first two of these problems and suggests means by which they may be reduced or overcome. Transportation and storage of fuel. Risk of explosion and fires. . 5. Gases and particulate in engine emission. 7. 6. Noise. Heat and Humidity. 4. High speed in long hauls. the pollutants in diesel exhaust are. EXPANSION AND SCRUBBING . details of which are followed.GASES AND PARTICULATES IN DIESEL EXHAUST In addition to heat and water vapor. a) Carbon monoxide (CO) b) Carbon dioxide (CO2) c) Oxides of Nitrogen (NOx) d) Sulphur dioxide(SO2) e) Particulate and Unburned Hydrocarbons (UBHC) f) Respirable Combustible Dust (RCD) The above polluting contents in the diesel engine exhaust are to be controlled by the scrubbing method. so that effective cooling takes place within the short span of time available for the gas to pass through the water. After expansion. This considerable reduction of backpressure allows for the additional involved due to the introduction of water and lime stone container. This expansion allows the gas to cool. The venture effect of the bell – mouth is minimized because the exhaust gas escapes out of the bell – mouth randomly along the periphery. This allows the exhaust gas to expand considerably. because the temperature is a function of pressure. The length of bubbling can be increased by the water level in the scrubber tank. (which could be otherwise being any alkaline solution) where the obnoxious products of combustion are scrubbed when bubbled through it. the emission comes in contact with water. The bell – mouth also allows for more contact area with water.The high temperature high pollutant exhaust gas is allowed to pass through the bell – mouth assembly of the scrubber in the first phase. . The bell – mouth at the inlet/outlet is approximately 2 ½ times more in an area is that of the inlet. the products of combustion to go through a series of chemical reactions. The baffles are of invaluable help to reduce the carryover of water particles which are converted into steam. and provides for an increased contact area with the scrubbing agent. The chemical reactions in their different phases are . which inadvertently affect the performance of the engine. And for this reason the bell – mouth is a multipurpose component. Now due to high temperature of the exhaust gas and the high chemical reaction prone lime stone.But this will be increased result in an abnormal backpressure. allows the exhaust emission to pass through limestone radically. it comes in contact with baffles. which otherwise will escape out of the system. After bubbling through the water. so that more obnoxious product is absorbed in the allowed time. which is provided above the baffles. This allows for the thorough scrubbing of the emission. A lime stone container. to allow for reduction in back pressure. which encourage turbulence of the exhaust gas within and below the water surface without unduly increasing the back pressure of the exhaust. The area at any particular and results are explained in the subsequent chapter. even if it is in glowing conditions. The procedure and results are explained in the subsequent chapter. By this method.explained later in this chapter. Chemical Reaction 1 The obnoxious product of combustion is NOx – the oxides of Nitrogen. The area at any particular section in the whole system is more than the outlet of exhaust manifold of the engine. DETAILS OF CHEMICAL REACTIONS In the scrubber tank water is used as a alkaline solution mainly to dissolve the Unburned Hydro Carbons (UBHC). which contributes to the reduction of backpressure of the system as a whole. The extent of scrubbing can be analyzed by using an ORSAT apparatus very easily. it is dissolved in water. thereby it is suppressing a spark which could escape from the engine to the inflammable environment. the UBHC. Water will absorb the oxides of . Ca (OH)2 + 2HNO3 Ca(NO3)2 = 2H2O Ca (OH)2 + 2HNO2 Ca(NO2)2 + 2H2O……….. The calcium carbonate when further exposed to carbon-di-oxide. calcium-bi-carbonate will be precipitated.Nitrogen to a larger extent. further reaction takes place as below.. Ca(OH) + CO2 CaCO3 = H2O . NO2 + 2H2O 2 HNO 2 + 2HNO3 (Diluted) ………….II Chemical Reaction 3 When the carbon-di-oxide present in the exhaust gas comes in contact with the limewater. for the above statement.I Chemical Reaction 2 If a small amount of limewater is added to scrubber tank. The following chemical reaction will enhance the proof. calcium carbonate will precipitate. The following is the chemical reaction. Also the negligible volume (0. which is resulted from the above reactions. accurately. The following equation gives the chemical reaction and calcium sulphite will precipitate. it will not readily react with water or with any by – products.. But the small trace of sulphur-di-oxide makes it little difficult to measure the magnitude of the chemical reaction.2%) of CO present in the Diesel emission is not such a menace. when compared to the petrol engine exhaust which as high as 10% of CO. the time limitation for . the limewater absorbs a part of the oxides of Nitrogen..IV Because CO is chemically balanced and stable.III Chemical Reaction 4 The sulphur-di-oxide present in the Diesel Exhaust also reacts with the limewater. Ca (OH) 2 + SO2 CaSO3 + H2O………. Even though.CaCO3 + H2O + CO2 Ca(HCO3)2………. carbon-di-oxide. The following are the chemical reactions for the oxides of Nitrogen (NOx) Carbon-di-oxide (CO2) and Sulphur-di-oxide (SO2).the reaction take place allows a considerable percentage to escape. encourages further chemical reaction. (CaCO3). the stone container. which evaporates from the scrubber tank due to the high exhaust temperature (400°C . the liberation of Carbon dioxide is very less. But. calcium sulphite will precipitate and CO2 will be by-product. which is provided with limestone or calcium carbonate. in the presence of steam. . Because of the small percentage and SO2 presence. Chemical Reaction 6 CaCO3 + SO2 + H2O CaSO3 + CO2 + H2O…VI From calcium carbonate. But the liberated CO2 will again combine with CaCO3 to form calcium bicarbonate as mentioned in equation 5.700° C). . calcium Nitrate Ca(NO3)2 and calcium Nitrite Ca(NO2)2 are the by products. in the following manner.VIII i. The liberated CO2again combines with calcium carbonate to form calcium bicarbonate (equation 5). and CO2 is liberated. 4NO2 + 2H2O 2HNO2 + 2HNO3…VII The resultant products when come in contact with calcium carbonate the following reaction takes place CaCO3 + 2HNO3 Ca(NO3)2 + CO2 + H2O. DIESEL SMOKE AND CONTROL .. CaCO3 + 2HNO2 Ca(NO2)2 +CO2 + H2O……….Chemical Reaction 7 The presence of steam makes it possible to have a preliminary reaction with oxides of nitrogen.e. It originates early in the combustion cycle in a localized volume of rich fuel–air mixture. If. Any volume in which fuel is burned at relative fuel–air ratio greater than 1. The soot particles.EXHAUST SMOKE Smoke. and if insufficient quantity. Black smoke. The size of the soot particles affects the appearance of smoke.5 and at pressure developed in diesel engines products soot. The smoke of a diesel engine is. which have an objectionable darkening effect or diesel exhaust. two basic types A. is due to poor combustion. agglomerate into bigger particles. in general. which are chain–line clumps of carbon. If this soot. it is not burned in combustion cycle it will pass in exhaust. type of fuel and pressure. B. once formed finds sufficient oxygen it will burn completely. The amount soot formed depends upon local fuel–air ratio. Blue–white smoke. will become visible. . which is defined as visible products of combustion. ) Black smoke Black smoke is carbon particles suspended in the exhaust gas. Also. when lubricating oil flows past piston rings.A.) Blue–White smoke The blue–white smoke is caused by liquid droplets of lubricating oil or fuel oil while starting from cold. It largely depends upon air–fuel ratio and increases rapidly while load is increased and the available air is depleted. This results in bluish or white smoke when exhausted. CAUSES OF SMOKE As mentioned earlier the cause of smoke is incomplete burning of fuel inside the combustion chamber. the result is blue–white smoke. indicates that piston rings are worn out and maintenance is required. Due to lower surrounding temperatures the combustion products are at relatively low temperature and intermediate products of combustion do not burn. B. other than cold starting. . Blue white smoke. which passes across the piston rings. . such as injection system characteristics. the fuel used. and thus has a profound effect on smoke generation tendency of the engine.Two main reasons for incomplete combustion are incorrect air–fuel ratio and improper mixing. unsuitable droplet sizes. All these substantially increase the smoke levels. These might result due to engine design factors. secondary injection and improper dispersion atomization. INJECTION SYSTEM The injection system characteristics. Good maintenance is a must for lower smoke levels. the induction system. The maintenance affects the injection characteristics and the quantity of lubricating oil. which can affect smoke levels. and excessive duration of injection. include inadequate or excess penetration. governor control. RATING The engine condition plays a very important role in deciding the smoke levels. and the engine rating. However. Hence any overloading of the engine will result in a very black smoke. During the first part. The smoke level will rise from no load to full load. in the higher load there is an abrupt rise in smoke level due to less available oxygen. In general. more volatile fuels give less smoke than heavier fuels of similar cetane number. ENGINE TYPE AND SPEED . The centane number has no effect on production of black smoke. as there is always excess air present.FUEL The quality of fuel affects the while smokes produced in an engine. High cetane number and high volatility both improve the cold smoking performance of an engine. LOAD Rich fuel–air mixture results in higher smoke because the amount of oxygen available is less. the smoke level is more or less constant. clearly indicating that the diesel engine has a mixing problem even in the presence of excess oxygen.The smoke is worse at low as well as at high speed. the air motion generated in diesel combustion chamber tends to mismatch the fuel motion at the two ends of the speed range resulting in deterioration of smoke level. This increase in smoke occurs even with as much as 25 percent excess air in cylinder. Whenever. In contrast to mixed and homogeneous fuel–air in gasoline engines. the . In addition. MECHANISM OF SMOKE FORMATION Diesel smoke originates early in the combustion process. FUEL–AIR RATIO The smoke increases with increasing fuel–air ratio. at low speeds due to charge heating and at high speeds due to wire drawing at inlet valve. This follows the volumetric efficiency curve of the engine in some measures as it drops at the extremes of speed. the diesel combustion chamber has different fuel–air ratios in different parts. it is exhausted and if in sufficient quantity it becomes visible and calls it as smoke.5 or higher and at pressures developed in diesel engine soot is produced. type of fuel and the pressure.fuel is burned in some localized portion of combustion chamber at fuel–air ratios corresponding to FR = 1. The structure of soot is given below. if the soot does not find sufficient oxygen to burn. There is a string suggestion that it is a poly–benezoid substance that can cause lung cancer. MECHANISM OF SOOT FORMATION All soot’s have a graphite structure with hexagonal basic carbon units forming a small crystalline atom. However. this soot is consumed during the latter part of the combustion. The amount of the soot produced depends upon the local fuel–air ratio. Normally. . . .The basic reaction of soot formation is yet unknown but the following theories have been advanced.e. So when particles are already present in some form. According to the second theory the hydrocarbons. Once it sticks to the metal it is very difficult to remove it. The reaction forming carbon monoxide (2CO = C +CO 2) is strongly catalyzed by carbon. so it has tremendous agglomeration properties and can be absorbed in metal surfaces.. it is a powerful absorption agent. 1. Soot has a free valency available. i. 2. they build up rapidly and then polymerize. decompose into simple small basic units of C 2 and C3 and these small radicals polymerize to form C6 ring polymers. especially heavy ends. the visual assessment depends on gas velocity and background.g. 1) Filter darkening type. The light extinction meter can be used for continuous measurements while. e.MEASUREMENT OF SMOKE Visual judgment of smoke levels is not possible due to light effects under varying conditions. which is blackened. the filter type can be used only under steady state conditions. 2) Light extinction type. which are used to measure smoke density. to various degrees depending upon the amount of carbon present in the exhaust. A measured volume of exhaust gas is drawn through a filter paper. BOSCH SMOKE METER Borsch smoke meter is filter darkening type. The light extinction type of meters can measure both white and black smoke while. the filter paper type meters can give only black smoke readings. The density of soot is measured by determining the amount of light reflected from . There are two basic types of smoke meters. the sample volume. The intensity of the stain is measured by the amount of light.the sooted paper. The diameter of the filter paper. etc.. The continuously taken exhaust sample is passed through a tube of about 46cm length which has a light source at one end and photocell or solar cell at the other end. The exhaust sample is passed at a constant rate through a strip of filter paper moving at a pre set speed. all is well defined. The amount of light passed through this smoke column is used as an indication of smoke level. . HARTRIDGE SMOKE METER This smoke meter works on the light extinction principal. which passes through the filter and is an indication of the smoke of light. Bosch and Van Brand smoke meters differ in the first the amount of light reflected is the measure of smoke level while in the second amount of light passing through the filter to indicate smoke level. VAN BRAND SMOKE METER Van Brand Smoke Meter is also filter darkening type. which passes through the filter and is an indication of the smoke density of exhaust. A stain is imparted to the paper. a number of solar cells are used. This makes the instrument very sensitive and accurate.S. A buffer space is provided so that smoke particles and vapor do not condense on the glass plates used. However. . Smoke meter designed by using a three-way cock is used to pass clean air or exhaust smoke through the smoke meter column.This smoke density is defined as the ratio of electric output from the photocell or solar cell when sample is passed through the column to the electric output when clean air is passes through it. The output from the solar cell is fed to a micro – voltmeter and light source is provided with control to vary the amount of light. if needed. Instead of a conventional photocell.A. but it differs from the Hartridge meter in that in this meter whole of the exhaust gas is passed through the meter to avoid any sampling error. UTAC smoke meter This also works on the light extinction principle. because of any change in the tube characteristics due to prolonged use of the meter. this is not very suitable for large engines due to its prohibitive size. This type of meter is useful for continuous testing and can be used in vehicle. The U. Public Health Service (PHS) has also developed a similar smoke meter. at which most of the time the engine will . Maintain the engine in best possible condition. Derating. DERATING At lower loads the air–fuel ratio obtained will be higher and hence the smoke developed will be less as already discussed. Run at lower load.CONTROL OF SMOKE The above discussions clearly indicate that the only method available to control the smoke level of a diesel engine is as follows: 1. The other methods are to change in combustion chamber geometry. MAINTENANCE Maintaining the engine in a proper way especially the injection system will not only result in significantly reduced smoke but also keep the performance of the engine at its best. 2. fumigation. and use of smoke suppressant additives The amount of equipment required achieving a reduction in some. i. However this means a loss of output.e. which will taper off at higher speeds. and if formed they break it into fine particles. There is a very small effect on engine smoke. Such devices need much development before they can be used in practice. CATALYTIC MUFFLERS Unlike petrol engine the use of catalytic mufflers are not very effective. the use of barium salts increases the deposit formation tendencies of engine and reduces the fuel filter life. SMOKE SUPPRESSANT ADDITIVES Some barium compounds if used in fuel reduce the temperature of combustion. thus avoiding the soot formation.run do not make it an attractive methods of smoke control especially when other methods of smoke control. However. are available. the strict air pollution regulations can expedite development in this direction. However. thus appreciably reducing smoke. This starts pre–combustion reactions before and during the compression stroke resulting in reduced chemical delay because the intermediate products such as peroxides and aldehydes react more rapidly with . like use of additives. FUMIGATION Fumigation consists of introducing a small amount of fuel into the intake manifold. notable Turk. There have been some attempts by various investigators. which come in the way of such evaluation.oxygen than original hydrocarbons. For this reason the following discussion of the odor problem is . which is responsible for soot formation. However. It may even happen that cracking does not occur at all because it requires about 80 kcal/mole to beak a double bond C=C and this energy may not be available due to easy oxidation during pre–combustion reactions. This shortening of delay period curbs thermal cracking. The most used method is to use a human panel to decide the odor intensity. These decreases as speed increases until a speed at which there is no effect of fumigation. to standardize this method but all these are unreliable due to many human factors. At low engine speeds 50 to 80 percent smoke reduction is obtained. DESEL ODOUR FOR CONTROL So far problem of odor measurement has eluded all instruments or analytical procedures to evaluate it. this improvement varies greatly with engine speed. The state of art odor measurement is still in the developing stage and will take at least a few years before some reliable method of odor measurement is evolved. Fumigation rate of about 11 to 15 percent gives best smoke improvement. general in approach and no specific or rigid rules can be formulated regarding this. the concentrations as low as 1ppm are irritating to the human eyes and nose. A number of odor producing components like nepthaldehyde. being less than 30 ppm. This partial oxidation may be because of either very lean mixture such as during idling or due to quenching effect. This standard is now in vogue because of the absence of a better method for odor evaluation. MECHANISM OF ODOR PRODUCTION Some experimental results indicate that the products of partial oxidation are the main cause of odor in diesel exhaust. a – butylbenzene. etc. A good correlation has been found between the flammability limits and the odor intensity of diesel exhaust. This is subject to error due to varied human response to same type of odor and other subjective factors. The members of the aldehyde family are supposed to be responsible for the pungent odors of diesel exhaust.. are given standard things and a trained human panel gives odor ratings to the given exhausts sample by comparison. . The objectionality of diesel exhaust odor is characterized by having intensity rating to it. Though the amount of aldehydes is small. This along with the nature of diesel fuel– air distribution explains the mechanism of odor production. . FACTOR AFFECTING ODOR PRODUCTION It shows the relation between odor producing components of exhaust and engine factors for both diesel and petrol engines. the reactants are quenched during this period. Also. . This is most likely to occur during idling and / or part load operation of the engine. partial oxidation products will result in odor in diesel exhaust. which are too lean to burn. It is interesting to note that even clear exhaust may carry highly pungent odors. special odorants in diesel exhaust have neither been isolated nor identified. The fuel in these regions.In diesel combustion there are most probable regions which the fuel/oxygen/inert mixture is outside the flammability limits. But still. might only partially oxidize resulting in odorous products of incomplete combustion. the fact that chemical reaction takes place during the second stage of diesel combustion suggest that if. FUEL–AIR RATIO The fact that very lean mixtures result in odorous diesel exhaust has already been discussed. The changes in fuel composition result in different second stage combustion time in diesel combustion and it is expected that this will affect the degree of oxidation if quenching is taking place. the results contradict this expectation.ENGINE OPERATION MODE It has been found that the mode of operation of the engine significantly affects the exhaust odor. The odor intensity from all the engines is more or less the same. . ENGINE TYPE The odor intensity does not vary with the engine. The only difference found is that the odor intensity from the exhaust of four stroke normally aspirated engine does not vary much with the mode of operation. FUEL COMPOSITION It is really surprising to find that the composition of the fuel has no effect on exhaust odor intensity. Maximum odor occurs while accelerating from idle and minimum odor results when the engine is run at medium speed and or part load. However. ODOR SUPPRESSANT ADDITIVES Different manufacturers of odor suppressant additive compounds that they reduce the odor have claimed it. small and rather insignificant effects upon the odor have been found in comparison of exhausts from treated and untreated fuels. reduce odor intensity but the state of art still leaves much to be desired. However. . The various standards and human panel evaluation procedure have undergone such drastic changes that there is no point in giving details of odor test results. CONTROL OF ODOR The factor that the experimental study of exhaust odor is seriously handicapped by the lack of standard tests has not allowed much work to be done in this direction. No predictable and reliable correspondence between the activities and odor is found. from time to time. Catalytic odor control system containing the muffler and / or catalyst container are under development and it has been found that certain oxidation catalysts if used under favorable conditions. It compares the odor from diesel and petrol engines. CHAPTER-IV DESIGN OF EQUIPMENT AND DRAWING . Water level indicator 6. Treated gas .CHAPTER-IV DESIGN OF EQUIPMENT AND DRAWING 4. Exhaust gas from engine 2. Tank 4. Water & lime stone 5.1 GENERAL MACHINE SPECIFICATIONS: The design and fabrication of aqua silencer movement consists of the following components to full fill the requirements of complete operation of the machine. 1. Bell mouth 3. DRAWING . 4.2 DRAWING FOR DESIGN AND FABRICATION OF AQUA SILENCER . CHAPTER-5 WORKING PRINCIPLE . By using water and lime stone mixture the back pressure will remain constant and the sound level is reduced. Using the perforated tube the fuel consumption remains same as conventional system.CHAPTER-5 WORKING PRINCIPLE The aqua silencer is more effective in the reduction of emission gases from the engine exhaust gas using water and lime stone mixture. The water contamination is found to be negligible in aqua silencer. It is smokeless and pollution free emission and also very cheap. By using water as a medium the sound can be lowered and also by using limestone in water we can control the exhaust emission to a greater level. The aqua silencer’s performance is almost equivalent to the conventional silencer. because the amount of acidity level in aqua silencer is expected to be below the dangerous acidity. . CHAPTER – 6 ADVANTAGES AND DISADVANTAGE . Considering the available fuel resources and the present technological development. mining and many other industries. . Diesel fuel is evidently indispensable In general. DISADVANTAGE Need to alter the silencer which may increase the total weight of the vehicle. the consumption of fuel is an index for finding out the economic strength of any country. Agriculture.CHAPTER – 6 ADVANTAGES AND DISADVANTAGE ADVANTAGES Diesel engines are playing a vital role in Road and sea transport. 7 APPLICATION .CHAPTER . . which otherwise will be hazardous.CHAPTER .7 APPLICATION For achieving this toxic gases are to be reduced to acceptable limits before they are emitted out of this atmosphere. CHAPTER-8 LIST OF MATERIALS . CHAPTER-8 LIST OF MATERIALS FACTORS DETERMINING THE CHOICE OF MATERIALS The various factors which determine the choice of material are discussed below. The various requirements to be satisfied Can be weight. Chemical The various physical properties concerned are melting point. Mechanical c. electrical conductivity. From manufacturing point of view d. specific heat. specific gravity. Properties: The material selected must posses the necessary properties for the proposed application. surface finish. Physical b. reliability etc. The various Mechanical properties Concerned are strength in tensile. . 1. magnetic purposes etc. ability to withstand environmental attack from chemicals. rigidity. coefficient of thermal expansion. The following four types of principle properties of materials decisively affect their selection a. thermal Conductivity. service life. eleastic limit. 3. . Quality Required: This generally affects the manufacturing process and ultimately the material. torsional and buckling load. 2. Cast ability Weld ability Surface properties Shrinkage Deep drawing etc. it would never be desirable to go casting of a less number of components which can be fabricated much more economically by welding or hand forging the steel. For example. bending. wear resistance and sliding properties. hardness. The various properties concerned from the manufacturing point of view are. Manufacturing case: Sometimes the demand for lowest possible manufacturing cost or surface qualities obtainable by the application of suitable coating substances may demand the use of special materials. impact resistance.Compressive shear. endurance limit. and modulus of elasticity. fatigue resistance. The delivery of materials and the delivery date of product should also be kept in mind. and nonmaintenance of the designed part are involved in the selection of proper materials. It then becomes obligatory for the designer to use some other material which though may not be a perfect substitute for the material designed. in selection of material the cost of material plays an important part and should not be ignored.4. . Cost: As in any other problem. Space consideration: Sometimes high strength materials have to be selected because the forces involved are high and space limitations are there. Availability of Material: Some materials may be scarce or in short supply. Sometimes factors like scrap utilization. appearance. 6. 5. CHAPTER-9 CONCLUSION . i.9%.36%. by using AQUA Silencer the NOx will be reduced to 29. In the Smoke Density will be reduced to 67. In No load condition.CHAPTER-9 CONCLUSION The aqua silencer is more effective in the reduction of emission gases from the engine exhaust gas using perforated tube. The water contamination is found to be negligible in aqua silencer. The aqua silencer’s performance is almost equivalent to the conventional silencer. It is smokeless and pollution free emission and also very cheap. . By using water as a medium the sound can be lowered and also by using activated charcoal in water. because the amount of acidity level in aqua silencer is expected to be below the dangerous acidity.e. the Particulate Matter will be reduced to 70%. We can control the exhaust emission to a grater level. 250mg/lit. BIBLIOGRAPHY . Mathur and R. Environmental Pollution analysis Khopkar Methods of measurement of Air Pollution Indian standard Institution (ISI) Engineering Chemistry Jain and Jain. Internal Combustion of Engines.Crouse and Donald L.Angling. Waster water engineering treatment.Sharma.P. .L. William H.BIBLIOGRAPHY Automotive Emission Control. M. Matecarf and eddy. . PHOTOGRAPHY .
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