PURIFIERBOWL Produces high centrifugal forces through rotation making possible separation and clarification. OPERATING WATER In the rotating bowl the incoming, rotating operating liquid generates a high centrifugal pressure. This pressure is utilized for actuating the annular piston and sliding piston which closes and opens the bowl.GRAVITY DISK Hold the interface between the light liquid and heavy liquid in the bowl within a definite rage.

DISC SEPARATROR is a kind of settlement type centrifuge for the separation of materials difficult to separate; such as the viscous liquid and composed of small solid particles.HOW DOES IT WORK? When the denser solids are subjected to such forces, they are forced outwards against the rotating bowl wall, while the less dense liquid phases form concentric inner layers. The area where these two different liquid phases meet is called the interface position. This can be easily varied in order to ensure that the separation takes place with maximum efficiency. VACUUM DEHYDRATOR A vacuum dehydrator is one of thevery few methods to remove dissolved water from oil. KINDS OF FILTERS Hydraulic Filter - are very useful for removing solid contamination from lube and fuel oil systems of marine machinery. Fine Mesh Screen Filter - It is the most commonly used filter in lube and fuel oil systems on board. It can be used both on suction and discharge side of the system. Cartridge Filter - used for fuel oil and lube oilfiltration. They are normally of disposable type and can be used only once.

METHODS OF F.O. AND L.O. TREATMENTPURIFICATION separation of two insoluble liquids with different densities, and at the same time, removing of solid. CLARIFICATIONseparation of solid contaminants from a liquid GRAVITATIONAL SEPARATIONa dirty liquid in a stationary vessel will clear slowly as the heavy particles in the liquid settle to the bottom under the influence of gravity. In case of insoluble liquids the heavier liquid will place itself underneath the lighter liquid.CENTRIFUGAL SEPARATIONa rapid rotating vessel gravity is replaced by centrifugal force, which increases the settling velocity by a factor of several thousand. That takes hours under influence of gravity takes only seconds in a high speed separator bowl.THREE METHODS OF PURIFYING1. SETTLINGSettling by gravity is a slow process of removing contaminants;Settling is reduced at high temperature2. FILTERINGA. STRAINER Installed at the pump suction to remove large abrasive contaminants such as rust and scale. Strainers also contain a powerful magnet to remove iron particles. Magnetic strainers are often installed at the pump suction or in the return line to the oil reservoir as well as the pump discharge. b. FINE FILTERS Are use to remove micronic size particular matter from the oil.The wire mesh type filter, are made to filter out particles of below 125 microns in sizeThe auto-clean filter strainer are used if finer particles filtration is required, which con filter down to 25 micron in sizeC. FILTER COALESCENCEMethods of removing particulate and water removal from oil.It consist of pre-filter for particulate removal and inorganic coalescing unit which collect the waterA filter coalescence will remove solid particles of 3 microns and above 90% of the water present in oil.To clean the unit drain first, then the filter cartridge is removed the water repelling screen need not be touchedTWO METHODS OF CENTRIFUGING1. PURIFICATIONA method of centrifuging when the centrifuge is equipped with a clean oil discharge and a water discharge.It is actually a separation of two liquids of different densities including solid particles which one present during the process. 2.CLARIFICATIONIs a method of centrifuging designed for maximum separation of solid contaminants from a liquidIt is sometimes called dry separation because water seal is not required and no water seal is set up for clarificationThe centrifuge is set up with only one liquid discharge for the clean oil.

OPERATIONAL PRINCIPLE OF PURIFIERIt operates in the same way as the clarifier employing centrifugal force to throw solids

CENTRI LOCK Uses a lightweight, non-threaded snap ring. This prevents wear by allowing easy removal without a sledgehammer. SEAL RING a finger ring engraved with a seal TOP DISC This disc is only used in purifier modeDISC STACK Disc in the bowl hood for positioning the interface DISTRIBUTOR sediment adheres firmly, dissolve it by submerging in this partDISCHARGE SIDE This increases discharge accuracyand does away with metal-to-metal wearBOWL BODY Foundation of the bowl VALVE PLUGS arevalveswith cylindrical or conically tapered "plugs" which can be rotated inside the valve body to control flow through the valve.

Oil Purifier needs the following concerning oil: Temperature Before entering the purifier, the dirty oil passes through the heater. This increases the temperature, thus reducing the viscosity of the oil to be purified. The lower the viscosity, the better the purification. Quantity of Flow The flow rate of a purifier should be set to optimize removal of whole system impurities. The lower the flow of oil feed, the greater the time for impurity removal and the more efficient the purification. The higher the quantity, the greater the amount of system oil is purified per unit of time. Density/Specific Gravity Density/Specific gravity is also important to oil purifier because separation of the two liquids, such as water and oil and the solid particles will be easier. Because of the difference in gravity, oil will float on top of water since oil is less dense. The solid particles which is heavier will sink down. The specific gravity can tell us, based on its value, if the object will sink or float in our reference substance. Thedensityis a measure of how compact or heavy an object in a given volume.

GRAVITY DISCPurifiers have great role in marine ships. A ring fitted at the top of disc stack from where water is passing out is called a gravity disc. Oil which is for purification may not be of same type it is of different densities or viscosity, so the interface change. To create the correct interface between water and oil it is very important to select correct gravity disc size.FUNCTIONS OF GRAVITY DISC one which controls the output of the quality fuel Responsible for creating interface between oil and water Maintains the back pressureWHAT WOULD HAPPEN IF WE USE BIG DIAMETER/SMALL GRAVITY DISC?if we use big diameter gravity disc, the possibility of having water mix to fuel is high while if the diameter of the disc is smaller then the better fuel you get. If we are to use so small diameter disc , this will cause some good fuel oil to be thrown to the sludge tank . There is also a drawback if you use too much large disc because there is a possibility that the water will be mixed with the fuel. So it is very important to use the correct disc size

FUEL OIL Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power. TYPES OF FUEL OIL SOLID FUEL refers to various types of solid material that are used as fuel to produce energy and provide heating, usually released through combustion.Ex. Coal LIQUID FUELobtained from distillation and processes carried our on crude oil.Ex. Engine fuel, lubricants GASEOUS FUELexist naturally in the ground, are composed of hydrocarbons (such as methane or propane), hydrogen, carbon monoxide, or mixtures.Ex. LPG VISCOSITY Viscosity - the state of being thick, sticky, and semifluid in consistency, due to internal friction. Is the resistance of a fluidVISCOMETER Viscometer - is an instrument used to measure the viscosity of a fluid. 1 Stoke(St) = 0.0001 square meter/ second 1 Centistoke(cSt) = 0.000006 square meter/ secondPROPERTIES OF FUEL OIL FLASH POINTIs the temperature at which an oil will give off sufficient inflammable vapor to produce. CLOUD POINT indicate the temperature at which waxes begin to form. cloud point temperature is it depends on the fuel oil you use commonly ranging 20-25. POUR POINTis the temperature at which it ceases to flow.FUEL OIL QUALITYCETANE - a colorless oily hydrocarbon found in petroleum C16H34 Used in Diesel Engine The higher cetane no. the better Low cetane no. = Ignition DelayOCTANE - a chemical in petroleum that is used to rate the quality of different kinds of gasoline C8H18 Used in Gasoline Engine The higher octane no. the better Low octane no. = Engine knocksOIL TREATMENT Both fuel oils and lubricating oils require treatment before passing to the engine. This will involve storage and heating to allow separation of water present, fine filtering to remove solid particles and also centrifuging. The centrifugal separator is used to separate two liquids, for example oil and water, or a liquid and solids as in contaminated oil. Separation is speeded up by the use of a centrifuge and can be arranged as a continuous process. PURIFIER where a centrifuge is arranged to separate two liquids such as water and oil.CLARIFIER where a centrifuge arranged to separate impurities and small amount of water from oil.

present in the oil to the side of the bowl and accumulated therein. However, in order for a purifier to operate as the centrifugal separator a water seal is necessary.RELATIONSHIP BETWEEN THE SIZE OF GRAVITY DISC AND THE INTERFACEGRAVITY DISC ( DAM RING)Control the radial position of the fuel and water interface.If the internal diameter of the gravity disc is too small, the separating efficiency will be formed within the disc pack.If the internal diameter is too large, the interface will form at a diameter greater than the top disc, and oil will flow/pass to waste through the water outlet. FACTORS THAT AFFECT THE POSTION OF THE INTERFACE1. Density ratio between the oil and water2.Viscosity3.Flow rate4.Variation in density of process liquid/oil INTERFACE MOVING INWARD BECAUSSE OF 1. An increase in temperature2.A decrease in viscosity3.A decrease in flow rate4.A decrease in back pressure5.Decrease in densityINTERFACE MOVING OUTWARD BECAUSE OF1. An increase in viscosity due to a decrease in temperature2. An increase in flow rate or3. An increase in density, this could result to a loss of liquid seal

STEERING GEARis the equipment provided on ships to turn the ship to left (Port side) or to right (Starboard side) while in motion during sailing. The Steering Gear works only when the ship is in motion and,does not work when the ship is stationary. All the ships are to be provided with, an efficientmain steering gear, anauxiliary steering gearand, except for very small ships, themain steering gearshould be power operated. THREE MAJOR COMPONENTS OF STEERING GEAR TELEMOTORComprises of two parts namely, transmitter and receiver. The transmitter is located on the bridge in the form of a wheel which transmit signal the given order to the receiver located in the steering gear compartment, by turning the steering wheel CONTROL UNITIs the link between the telemotor and power unit. It receives signal from the telemotor and operates the power unit until it receives the another signal, this time from the rudder to the hunting gear to stop. POWER UNITThe power unit provide the force, when required and with immediate effect, to move the rudder to the desired angle. Can be any prime mover like steam engine, diesel engine or an electric motor, directly coupled to the rudder

TWO KINDS OF STEERING GEAR SYSTEM MAIN STEERING GEARMeans the machinery necessary for effecting the movement of the rudder for the purpose of steering the ship under the normal service conditions. EMERGENCY OR AUXILIARY STEERING GEARMeans the equipment other than any part of main steering gear necessary for effecting the movement of the rudder for the purpose of steering the ship in the event of the failure of the main steering gear, but not included the tiller, quadrant or components serving the same purpose.

DE-SLUDGING Desludging breaks up the sedimentation and separates out the hydrocarbons, water and solids. The process of removingsedimentsbydrainingandcleaninga tank.

Steering gear ASteering Gearis the equipment provided on ships to turn the ship to left (Port side) or to right (Starboard side) while in motion during sailing. The Steering Gear works only when the ship is in motion and,does not work when the ship is stationary. All the ships are to be provided with, an efficientmain steering gear, anauxiliary steering gearand, except for very small ships, themain steering gearshould be power operated. CompleteSteering Gearsystem consists of three main parts namely Telemotor Control Unit Power Unit.

A brief description about the construction and working of these components is as followsTelemotorunit comprises of two parts namely,TransmitterandReceiver. The Transmitter is located on the which transmits the given order to the Receiver located in the steering gear compartment, by turning the steering wheel. The Receiver conveys this order to the Control Unit, also located in the steering gear compartment, via linear motion.navigation bridge in the form of a wheel,The Telemotor is generally hydraulic type, electric type or, as is the case with modern steering systems, it could be electro-hydraulic type. In olden days, Telemotors were purely mechanical type consisting of linkages and chains with sprockets. As they were operated manually, they required very healthy sailors to operate them.Control Unitis the link between the Telemotor and the Power Unit. I receives signal from the Telemotor and operates the Power Unit until it receives another signal, this time from the Rudder through the Hunting Gear, to stop the operation of Power Unit. Power Unitcan be any prime mover like steam engine, diesel engine or, an electric motor, directly coupled to the Rudder; it can be an electro-hydraulic unit or, an all- electric unit complete with the Telemotor.Manually operated, mechanicalSteering Gearswere in use during sailing ship days. Sailors with strong body were required to operate theSteering Gears. Later on, after the onset of steam engines, mechanized gears were used. Modern ships use all very sophisticated Steering Gear systems which could fall in either of the categories Fully hydraulic type Electro-hydraulic type Fully electric type

Name three basic requirements for steering gear.The three basic requirements of steering gears are - to be continuously available ,move the rudder rapidly to any position of degrees in response to the order form the bridge during manoeuring and hold it in the required position -have arrangement s for relieving abnormal stress and returning it to its required position-maintain the ship on course regardless of wind and waves. Why are jumping stops fitted? Jumping stops are fitted to prevent the lifting of the rudder and stock in heavy weather.

. In ram type hydraulic steering gear, How is side loading relieved on the cylinder glands? In ram type hydraulic steering gear, load is relieved on the cylinder glands by the crosshead slippers bolted to the side of the rams, which slide on a machined surface of the guide beam. How are ram cylinders braced againts hydraulic pressure which tends to push them apart? The cylinder are braced together by the guide beam because hydraulic pressure tends to push them apart. The cylinders also have feet that are bolted to stools on which the gear is mounted. In four cylinder sets, adjacent cylinders are cross braced by heavy brackets

How can the rudder be locked, in an emergency, in a hydraulic steering gears? In an emergency in hydraulic steering, the rudder can be locked in position by closing the supply valves to each ram. How is hydraulic steering gear protected against overloading by heavy seas on the rudder ? Hydraulic steering gear is protexted against overloading by heavy seas acting on the rudder by relief valves which operate around 10% above normal working pressures, oil being passed to one side of the system to the other . The hunting gear will correct the rudder movement putting the steering gear pump on' stroke'

In hydraulic steering gear ,why should special attention be paid to high pressure oil pipes (especially after heavy weather ) ? In hydraulic steering gears, attention should be paid to high pressure oil pipes because, in some cases, it has been know for the pipes to fracture at necks especially after heavy weather. What rudder angle is permitted by a rotary vane steering gear with two moving and two fixed vanes ? The rudder angle permitted by rotary vane steering gear with two moving and two fixed blades is 75 degrees to port and 75 degrees to stbd , and in three moving and three fixed blades is 35 degrees port and 35 degrees stbd.

ELECTROHYDRAULIC STEERING GEAR The direction of a ship moving through the water is controlled by changing the angle of its rudder, located in the stern of the ship. As the gross tonnage of ship increases, more and more force is required to move the rudder through the required angle. On a large ship, the power required to position the rudder is provided by one or more electrohydraulic steering engines which respond to rudder orders transmitted electrically from the helm (steering wheel) in the pilot house to the steering gear, located directly above the rudder in the stern. The steering engine or gear transmits power from the steering engine to the rudder stock. The term steering gear normally includes the driving engine and the transmitting mechanism. Although several different designs of steering engines are in common use, their operating principles are similar.Hydraulic TelemotorThe telemotor has become, on many vessels, the stand-by steering control mechanism, used only when the electric or automatic steering fails. It comprises a transmitter on the bridge and a receiver connected to the steering gear variable delivery pump, variable delivery pump This type of pump can be controlled by just moving a spindle. The pump is driven by an electrical motor at constant speed. By moving the control spindle away from the central point, the pump stroke increases, and the hydraulic fluid is pumped in one direction. Moving the spindle more from the central point will cause more fluid to be pumped and consequently more pressure is generated to drive the rams. Moving the control spindle back to the original position and then away in the opposite direction causes the hydraulic fluid to be pumped in the reversed direction. The rams will also move in the reversed direction. Floating Lever Feedback MechanismWhen the rudder stock has reached the desired angle, the pump control lever moves back to the original position, and the pumping action stops. The rudder is stopped at the required angle. Moving the steering wheel to the opposite direction will cause the rudder to come back to the original zero position.

Variable Delivery Pump generally used in applications, which require constant variation in the amount of oil that is to be supplied. is to alter the pump stroke in order to vary the amount of oil displaced, according to the requirement. radial cylinder Hele Shaw pump It consists of a short shaft, which is attached to a cylindrical body that rotates inside the casing. The cylindrical body surrounds a central valve and has ball bearings at the ends. The central valve and the cylindrical ports are connected to each other by means of ports, which open in the outer casing from where the oil is supplied and delivered Working principle the circular ring, which accommodates the slippers is concentric with the central valve arrangement . Due to this, the piston doesn't have any relative reciprocating motion inside the cylinder. No oil is pumped or sucked in and although the pump is rotating no fluid is delivered, during this state. But this is only until the arrangement is concentric. As soon as the circular floating ring is pulled to the right the pistons in the cylinder undergo a reciprocating motion. The lower piston moves inwards and discharges fluid through the lower port. The piston moves till the horizontal position and then moves outwards in the opposite direction, drawing in fluid through the upper ports. Thus in this way the top ports act as suction ports and the lower ports act as discharge ports. If the circular ring is pushed to the left direction, the suction and discharge ports are reversed.Variable Stroke Reversible Swashplate Pump it runs in the flooded condition, the make up tank being above the level of the pump so that all the working parts are immersed in oil. It is driven by a constant speed electric motor the volume and direction of the oil flow being controlled by means of a stroke control lever. Working Principle The slipper pad is an improvement on the swash plate which provides higher pressure. The driving shaft rotates the cylinder barrel, swash plate and pistons. An external trunnion (short shaft) enables the swash plate to be moved about its axis. The cylinders in the barrel are connected to ports which extend in an arc around the fixed pott plate. When the swash plate is vertical no pumping action takes place. When the swash plate is tilted pumping occurs, the length of stroke depend Depending upon the direction of tilt the ports will be either suction or discharge.ing upon the angle of tilt. The process of pump in the steering system The steering starts at the Bridge. The required rudder angle is transmitted hydraulically or electrically from the steering wheel at the Bridge to the telemotor at the steering gear, just above the rudder. There are a few common arrangements for using hydraulic power. There are the 4-rams, 2-rams, and rota The heart of these hydraulic systems is thevariable delivery pump. This type of pump can be controlled by just moving a spindle.ry vane types. The pump is driven by an electrical motor at constant speed. By moving the control spindle away from the central point, the pump stroke increases, and the hydraulic fluid is pumped in one direction. Moving the spindle more from the central point will cause more fluid to be pumped and consequently more pressure is generated to drive the rams. Moving the control spindle back to the original position and then away in the opposite direction causes the hydraulic fluid to be pumped in the reversed direction. The rams will also move in the reversed direction. By using a floating lever feedback mechanism, when the rudder stock has reached the desired angle, the pump control lever moves back to the original position, and the pumping action stops. The rudder is stopped at the required angle. Moving the steering wheel to the opposite direction will cause the rudder to come back to the original zero position.

Automation of Steering SystemA good automatic pilot can improve the profit margin of a vessel in two ways. Firstly it enables a reduction to be made in the number of ships personnel and secondly a considerable in saving the fuel can be achieved if the vessel makes good its course with little deviation. A very important component of a ship is the rudder and steering system.Telemotor controlIs a hydraulic control system employing a transmitter, a receiver, pipes and a charging unit. The transmitter, which is built into the steering wheel console, is located on the bridge and the receiver is mounted on the steering gear. The charging unit is located near to the receiver and the system is charged with a non-freezing fluid.Monitoring of Steering SystemThe monitoring system should include an integrated alarm function that reports out-of range events.Things to be Monitored in Steering System : Level of Hydraulic Oil Rudder Angle Indicator Limit Switch Stopping Device Alarm Power FailureAlarms of Steering SystemSteering gear alarm system is used for monitor of steering gear. Alarms should be managed automatically. Alarm limits should only be set by authorized users and should automatically alert responsible staff by using communication medium in case of out-of-range events or incidents. SWITCH LEVEL 1:Thelevel switch 1gives an initial alarm following a loss of oil from either system.SWITCH LEVEL 2:When no action is taken immediately upon the previous alarm, the loss of oil continues and over a period of time this loss of oil initiates one or both of the level switches 2. SWITCH LEVEL 3:This switch will get activated when there is still no further improvement in the loss of oil on the faulty side.Alarms in Steering System : Power Failure Voltage Loss Oil Tank Level Low Oil Temperature High Control Power Failure

What is Electric Motor? Isanelectrical machinethat convertselectrical energy into mechanicalenergy. The reverse of this would be the conversion ofmechanical energyintoelectrical energyand is done by anelectric generator. How does an electric motor work? In a typical DCmotor, there are permanent magnets on the outside and a spinning armature on the inside. The permanent magnets are stationary, so they are called the stator. The armature rotates, so it is called the rotor.

What is Radial Pump? Aradial piston pumpis a form ofhydraulic pump. The working pistons extend in a radial direction symmetrically around the drive shaft, in contrast to theaxial piston pump. The piston starts in the inner dead center (IDC) with suction process. After a rotation angle of 180 it is finished and the workspace of the piston is filled with the to moved medium. The piston is now in the outer dead center (ODC). From this point on the piston displaces the previously sucked medium in the pressure channel of the pump.

Swash plate pumps have a rotating cylinder containing pistons. A spring pushes the pistons against a stationary swash plate, which sits at an angle to the cylinder.Aswash plateis a device used inmechanical engineeringto translate the motion of a rotating shaft intoreciprocating motion, or to translate a reciprocating motion into a rotating one to replace thecrankshaftin engine designs. Pumping action is controlled: 1. Proper clearance between plunger and its housing which leads to more oil in drain at higher pressure. 2. Swash plate may not be lapped properly which leads to oil leakage from there , as you may be knowing whenever plunger makes forward movement, there is some oil leakage from the plunger end to the swash plate which lubricate the swash plate, but if lapping is not perfect ,then chances of oil leak in more quantity in drain possible. 3. There may be problem with pressure controlling devise which leads to higher oil leak at higher pressure, but this will be clear as swept volume indicator will show higher value , may be more than 70 percent, normally when pump is healthy then it should run at 20-30 percent.