Engineering Systems and Components of Centrifuge

Engineering Systems and Components of Centrifugeverbal descriptionThe primary(prenominal) line of reasoning of the swimming decanter separator is to separate materials of different densities. In this course of studyation, the cartridge extractor is compulsory to separate the olive embrocate from water and any different solids such as stones.The decanter extractor ( propose 1) is take leave of the olive pressers convocation line made up of four important weapons de-leafing washing, olive quelling mill, horizontal malaxer, and the centrifuge. introduce 1 shows briefly what the assembly line consists of.The enters into the centrifuge atomic number 18 olives which possess undergone a number of mental do byes with the early(a) main elevator cars of the olive presser assembly line. These processed olives be referred to as legal profession. This cover is the commentary of the decanter centrifuge and contains stone, water, other chemical additives, and rock oil.T he centrifuge uses the concept of sedimentation to separate the cake into heavy molten and light liquid, the lighter liquid being the olive oil, which is the output demand from the dodging. Basically, payable to the difference in densities the cake and oil provide separate naturally given enough time (the oil floats on top of the cake). The centrifuge fastnesss up this process utilize high rotational speeds, working up to 4000G on the cake. This is useful since a process that would take hours to achieve could happen in a proposition of seconds. The centrifuge rotates at high speeds, resulting in the sepa balancen of the contents wrong the centrifuge according to their density, allowing the olive oil to be retrieved from the governing body 1. attach SCREENSHOT OF CENTRIFUGEOverview of OperationThe cake is input to the system finished a vitiated admittance tube encased in a wider be intimate. This hammer has an Archimedean spiral, i.e. the scroll, welded to it. The jazz in concert with the scroll is called the conveyor, and it is encased in a barrelful. The shaft, and thus as well the scroll is moody by a travel occlusion system. The cake fertilises into the scroll atomic number 18a where separation of the olive oil from the cake occurs due to the high Gs generated by rotation and the angle at one kibosh of the scroll. The olive oil and waste are output through nozzles at opposite ends of the centrifuge drum.The centrifuge is attached to the frame using a pillow obstruct bearing. The frame bridge overs the entirety of the system.Basic Sizing RequirementsBy comparing to existing centrifuges, the optimal drum diameter and rotational speed are 425 mm, and 3800 rev respectively. A 14 practice ratio (drum diameter compared to the drum length) is adopted, resulting in a centrifuge length of 1700 mm 2. A rim angle of 200 is taken, as explained in vermiform appendix 1.Specification SheetCentrifuge SpecificationsCentrifuge TypeTwo-pha se Horizontal uttermost Overall distance3 mMaximum Overall breadth1.5 mMaximum Overall Height1.5 mInput lay450 kg/hCentrifuge RPM3800Centrifuge Beach go200Centrifuge drum diameter425 mmCentrifuge diameter to length ratio14Centrifuge Length1700 mmCentrifuge shaft outer diameter120 mm shoe point platThe following tree diagram is a in writing(p) design of the centrifuge and its sub-systems. Please work on over to find the above mentioned tree diagram.Block DiagramThe following block diagram is a graphical representation of how the centrifuge works in send to extract the oil from the olives. This graphical representation will provide a better grounds of how the sub-systems interact with one another. Please turn over for the above mentioned block diagram.Brief explanation of the chosen components crash Frame ( image 2) A tray to which the drive is bolted down to stay in position. It is attached to the legs of the centrifuge lower casing. It determines the withdrawnness between the shaft of the move and shaft of the centrifuge.Figure 2 Drive FrameCentrifuge Frame (Figure 3) The boilers suit frame of the decanter, this supports the entire grammatical construction of the centrifuge.Figure 3 Centrifuge Frame speeding racing shell (Figure 4) The amphetamine casing covers the drum of the centrifuge. It blocks contaminants from devising liaison with the drum and restricts the user of the machine from making contact with moving parts, providing better safety.Figure 4 Upper Casing Lower Casing (Figure 5) The lower casing acts as a collector for the products bowd from the rotating assembly and transports them to receivers for onward handling. The casing has to keep these spaced entities apart. So it can be concluded that the casing as an oil collector at one end and a cake muster out collector at the cone-shaped side.Figure 5 Lower CasingFeed Tube (Figure 6) A tube that the cake is transported to the centrifuge from the malaxer. This is overly the input of the centrifuge. Its inner diameter is determined by its required input flow rate.Figure 6 Feed Tube3-phase locomote (Figure 7) The business leader back provides the initial torsion required to rotate the flush. The repulse chosen is the AEG AM 132M ZA4*3, a 3-phase motor which provides 7.5kW of power, with the possibility of increasing the power up to 9.2kW through a small modification, making this a flexible choice.Figure 7 3-Phase MotorBelt (Figure 8) The Flat pat connects the pulley of the 3-phase motor and the centrifuge drum together, transferring power. The chosen Flat- strike is a Polyamide A-3c belt since it provides the appropriate thickness, deductible tension, and coefficient of clangor, while to a fault being appropriate for the minimum pulley diameter. stoppage (Figure 8) The pulley is use to modify the speed of the drum and is connected to the motor. see A 8 x 10 mm rectangular severalise 70 mm long is added to the motor pulley in order to make sure that the pulley gyrates together with the motor shaft in such a way that there is no relative social movement between the two.Figure 8 Belt and PulleyBelt watch over (Figure 9) The purpose of the belt adjudge is to protect the belt and pulley system from any accidents. It prevents contact of the belt with any foreign objects by fish fillet them from entering the belt area without removing the guard first. This whitethorn prevent injuries and breakages.The guard to a fault keeps the belt area clean from any residual detritus generated during the process. It can be easily removed for maintenance and cleaning.Figure 9 Belt GuardFigure 10 Drum shell with Archimedes live insideDrum The drum (Figure 10) is a cylindrical tube with flanges at both ends. At one end, the liquid discharge drum hub, this is where liquids are discharged from the centrifuge, while on the other side the cake discharge hub is connected, this is where solids are discharged from the centrifuge. The separation medium reaches its maximum speed in the decanter drum. This causes the solids to settle on the wall of the drums inner diameter. This is all a result of the high centrifugal staff office, which acts on the particles.One distinctive peculiarity of the drum is its tapered shape. This tapered shape is referred to as the beach. The beach is a conical section at the end of drum. It has this conical shape to exert additional force on the solids, hence squeezing out the depart drops of liquid. In this part of the process the centrifugal force push the solids uphill. This design helps to elevate the solids above the waterline in the discharge chamber.Figure 11 Bearing Setup 2Front hub bearings This horizontal setup (Figure 11) is supported by the use of bearings which are cased in a pillow block. Bearings are utilize to reduce clang and the effects brought on the component through wear and tear. This bearing used in this assembly is a axial motion bearing. The roller bearing is a bearing in which the main shoot is transferred through elements in rolling contact.Pillow Block The fundamental activity of the pillow block is to mount the bearing safely, which enables the bearings outer ring to be stationary, while the bearing inner ring to rotate. The bearing is supported in a housing and sealed with a non-contacting flinger. This non-contacting flinger is a seal, as the ring implies it does not come into contact with the shaft. Its main application is to keep lubricants and shit from escaping, while at the same time it helps keep water, dust and other contaminants that could be harmful, out of the bearing assembly. It does this with the help of the centrifugal force.Rear hub Bearings The vertebral column hub bearing assembly is akin(predicate) to that of the front hub. Its main job is to support one side of the car transporter. This bearing also resists the axial thrust of the scroll.Figure 12 Generated 3D Representation of Conveyor.Conveyer The conveyer (Figure 12) is a central hub with a continuous helix welded to it. The conveyer is in the shape of an Archimedes bottom fitting inside the drum, between the 2 end hubs. This conveyer will baffle a small clearance in relation to the drum. It main job is to carry solids which have settled against the walls of the drum, then pushing these solids towards the beach where they can be discharged. Its main functions are to convey the solids after they form a cake, accept the feed and accelerates it up to the drum speed. The material used is EN 1.4571 which is a form of high speed steel (HSS). The conveyer is the transport tool in a decanter centrifuge. The conveyer rotates with a different speed in relation to the drum, subsequently transporting the settled solids towards the conical shape of the drum. Also, the speed at which the conveyer rotates in relation to the drum defines how long a solid spends in the drum. The pitch of the conveyer is cogitate to the transport performance of the centri fuge 2.This conveyor is comprised of two main sub-components the scroll, and the shaft. The scroll is welded to the shaft, which rotates. While the two obviously need to be machined separately and welded together for economic reasons, they will be considered as a single part the conveyor.Calculations NomenclatureVariable (Motor)DescriptionPPowerTtortuosityAngular f numberVariable (Flow)DescriptionVVolumeACross-sectioned Area of segmentLLength of segmentcakeDensity of cakeVariable (Belt)DescriptionDDriver/Motor pulley diameterdDriven/Shaft diametern1RPM of shaftn2RPM of motor pulleydAngle of contact for shaftDAngle of contact for motor pulleyCDistance between centrestThickness of beltbWirth of beltlLength of beltSpecific weight of beltDensity of beltVVolume of beltmMass per unit of measurement length of beltrRadius of pulleyRotational VelocityFCCentrifugal force on beltF1 stress in tight side of beltF2Tension in wanton side of beltFiInitial force required to overcome frictionCoef ficient of frictionFRResultant force of belt on shaftVariable (Deflection)DescriptionEYoungs modulus of materialIMoment of inactivity of shaftyDeflection in shaftVariable (Bearings)DescriptionP1Weight of conveyorP2Force exerted on shaft by beltRA response at bearing ARBReaction at bearing BVariable (Shaft)DescriptionBending focal pointShear StressMMaximum Bending Momentc outermost spoke of shaftIMoment of Inertia of shatTTorque appliedJPolar Moment of InertiarouterOuter gas constant of shaftrinnerInner radius of shaftCalculations and Sizinghooey SelectionSince the machine will make contact with biological materials, certain characteristics and requirements have to be met in order to ensure that the parts making up the centrifuge will not chemically alter or affect the product in anyway. A list of materials suitable for nutriment processing has been compiled by the FDA, based in the US. The 6th iteration of this code, released in 2013, gives specific requirements with regards to materials used in food-contact surfaces of equipment in chapter 4, subpart 4-101.11. Among these requirements are corrosion impedance and durability. Considering this, the material chosen for all the parts that will come into contact with the product namely the centrifuge and its casing the chosen material is EN 1.4571 Stainless Steel, which suitably fits all relevant requirements. 4REF FDA?Calculations to find motor required force back To find the torque required to turn the shaft at a speed of 3800 RPM, which has been determined to be optimal for this machine (Figure 13) and thus find the power needed and an appropriate motor.DiagramFigure 13 3D diagram of power transmission system referable to the complex effects of fluid flow on the resistance to turning, the required torque for operation will be name by chase away engineering a similar system.HAUS Centrifuge Technologies produce a horizontal decanter centrifuge that has a maximum RPM of 5400, and utilizes a motor with a po wer output of 11 kW that can process up to around 1 m3/hr of material 5. This is sufficiently similar to the system being discussed in this report and can thus be used to reverse engineer the torque requirements during steady state.Using the comparability Pdrum = Tdrum, the required torque may be found.Thus, the required power for the system will beSince the reverse engineered system aims for power losses due to inefficiencies and other factors, as well as the fact that that system has an overall large processing capacity, the required power value obtained can be put on to gauzyly larger than the true minimum requirement. However, this will account for any power losses during transmission as well as any potential extra power demands.ConclusionsThe chosen motor is the AEG AM 132M ZA4*. This has a maximum of 1440 RPM and 9.2 kW of power, with an efficiency of 87% when run at 100% RPM, and a weight of 56kg. This is a modification of the AM 132M ZA4 motor, which only produces 7.5 kW of power 3.The AM 132M ZA4* is a 4-pole, 3-phase motor, single-speed drive. The motor has a single drive and is an asynchronous type motor with an Aluminium frame. It also has an IP 55 rating, making it somewhat resistant to dirt, debris, and water a useful property for this use case, where spillages and leakages may occur.The motor manufacturer also specifies that the chosen motor has a shaft diameter of 38 mm, and a key of 10 x 8 mm should be used for any pulleys, with the keyway being 5 mm deep and 10 mm wide. The key should have a length of 70 mm 3.Calculations for the size of it of the inlet tubeAim To find the required dimension of the inlet tube so that an appropriate amount of material will be input at an appropriate speed.DiagramFigure 14 Diagram of flow in inlet pipeIt must first be ensured that the flow rate in the inlet tube (Figure 14) will be sufficient to allow for the design specifications. In this case, the design is specified as having an input rate of 450 kg/h r.It is assumed that the cake will have a density, cake of approximately 2000 kg m-3. Thus, the appropriate inner radius may be found.Converting the input rate to m3/hr m3/hr. This results in 6.22510-5 m3 s-1 flow rate.For a system of this kind, the flow velocity is generally in the reaching of 0.5 to 2 ms-1. For the sake of calculations, it will be assumed that an appropriate velocity for this specific system will be 1ms-1.ThusCross Sectional Pipe Area = Area = r2, therefore = 4.46 x 10-3 m.Thus, an inner radius of 5mm can be chosen. This will result in a slight decrease in flow velocity, (down to 0.8 ms-1), however this is well within the idealistic range. Seeing as this pipe will undergo no torque and very little forces, a standard 2mm thickness can be taken.Power Transmission The centrifuge shaft is required to be turned at a constant speed. The load is determined mainly by flow and amount of cake in the system, which are controlled through a process done by another system. T hus, the load on the system may be assumed to be largely unchanging. The torque required is also relatively low.As such, a belt and pulley system is an appropriate choice for drive transmission. This is cheaper than a gear train, and is also easier to have and replace if required. This also reduces the size of the entire assembly, as the motor may be placed laterally, with the shafts being parallel to each other.A compressed belt is chosen over a V-belt. While the wedging action of a V-belt means that more power can be catching, flat belts are more efficient, having a 98% efficiency. Flat belts also generally have a longer work life. Most importantly, flat belts may be used across large centre distances, unlike V-belts. Thus, due to the constitution of the setup a flat belt system is more appropriate. 6The larger pulley must also be crowned (curved slightly) so the belt may be kept tracking centred on the pulley 7.Flat-Belt CalculationsAim To analyse the forces acting upon the b elt, determining friction and tension due to transmitted torque, in order to find forces and stresses on the shafts.Assumption A polyamide A-3 flat belt with thickness 3.3mm is used to calculate the forces present 8.Figure 15 Diagram of belt and pulley systemThe outer diameter of the centrifuge shaft has been chosen to be 120 mm. To find the match motor pulley diameter, D (Figure 15) required in order to spin the centrifuge at the required 3800 RPM, assuming the motor will turn at its rated speed of 1440 RPM, the following relationship is used.dn1 = Dn2Where n1 and n2 are the RPMs of the respective shaft0.123800 = D1440D = 315.57 mmThis will be approximated to 0.316 m (or 12.5 inches), the closest standard pulley size. For this size, the crown of the pulley should be 1 mm high 9.Determining the angles indicated 8 = sin-1() = 0.197where C = 500mmd = 2sin-1() = 2.747D = + 2sin-1() = 3.536Length of belt, L = = 1.704mThickness and largeness of belt, t = 3.3mmb = 75mm (standard belt breadth chosen arbitrarily)specific weight of belt, = 0.042lbf/in3 = 1162.56kg/m3Volume of belt = t x b x l= 75 x 3.3 x 1704= 421.74 x 103 mm3Mass of belt = V = 1162.56 x 4.2174 x 10-4m3 = 0.49kgMass per unit length of belt, m = = 0.2877kgm-1It can be shown thatFrom dS = mr2 d where dS, is the force due to centrifugal force= FC dThis implies FC = mr22= = 163.34NThe difference in tension between the 2 sides of the belt is given byF = F1 F2 = = 109.3NFor initial tension Fi,Equating Fi with the force required to overcome frictionFi = T2 e from friction equation T1 = T2 eThe negative sign indicates that this is the force that must be overcome.To find F1 and F2 , Tension in the belt where T1 is the largest tension, to be FI = 0.8D = 3.536CT2 = F2Since, F2 = Fi + FC F2 = -F2 e0.8 x 3.356 + FC F2 = F2 e0.8 x 3.356 + 163.34 1 e0.8 x 3.356 F2 = 163.34 Therefore, F2 = F = F1 F2109.3 = F1 6.06Therefore, F1 = 115.36N conclusion the radial resultant force on the shaft,It can be assumed that the force will act approximately radially for the sake of calculations.By geometry = sin-1 = 0.197c = 11.3oFigure 16 Diagram showing forces acting on device driver pulleySolving horizontally (Figure 16)(115.36 cos 11.3) + (163.34) + (6.06 cos 11.3) = 282.40NSolving vertically(6.06 sin 11.3) (115.3 sin 11.3) = -21.42NFR = = 283.45N = tan-1 = 4.34oCalculating FC for the smaller pulleyusing the equation FC = mr22= FC = = 164NSince FC for the bigger pulley = 163.3N, the resultant force FR will be approximately the same as previously found for bigger pulley.The chosen belt has an allowable tension per unit width of 31 N/mm, thus the chosen belt may maintain a tension up to 2325 N. Thus, the chosen belt is appropriately size to