Pneumatic Conveying Design - Report Example

Design Proposal Author: Course Title: - Program: - Name of your Institution: --- [Instructor Name] Date: 27/10/2014 1 Executive summary The designed system will have a cost of $76,172 and conveyor belt will be 90m while the motor size will be 125kW. Idler spacing on both sides have many advantages because they will allow materials of certain density to be transported along the belt. Without idler spacing materials may not be transported with easiness without increasing the wear and tear of the belt. It allows the performance of the belt conveyor increase. Table of Contents 1Executive summary 2 2Introduction 4 3Technical Analysis 4 3.1Load 4 3.2Conveyor 4 4Design Solutions 10 5Recommendation 12 6References 13 2 Introduction Pneumatic conveying design is a system for transporting coal. This system enables the materials move from one point to another for industrial use. In this design, materials that are transported in pipes should be able to be compressed or made into fluid so that they can be transported in non-suspension flow. However in order for them to be transported easily, the system capability and characteristics of the materials plays. In designing the pneumatic conveying system three variables are involved mass flow rate of the conveying gas ( mf), flow rate of materials(ms) and resulting pressure required to drive the gas-solid mixture. The distance to be covered by materials during the transportation is important in design the system as this will enable one understand the minimum transport capability. The pick-up velocity of the materials is critical in the analysis of the system as it will determine the amount of materials to be transport. This becomes critical when designing the Pneumatic conveying system. 3 Technical Analysis The technical analysis for the this design proposal is present below 3.1 Load 3.2 Conveyor Design constraints Specifications for Conveyor: Required throughput: 2000t/hr Belt speed: 3m/s Density, = 810kg/m3 Take up: 20m from drive Idler Trough Angle: 450 Assuming we have a 3 roll-idler systems with trough angle and Taking surcharge angle PN400 was selected i.e.: PN 1200/4 Quality and Thickness determined from following Table: Grade: N Top cover: 3.0 mm Bottom cover: 1.5 mm The carrying capacity of the conveyor belt The carrying capacity of the conveyor belt is the cross-section area of the belt to be designed while is the density of material. V is the velocity of the belt and is the inclination angle. The assumption here is that there is no inclination angle thus; we can determine the cross-sectional area of the belt. Then area (A) = = = 0.168m2 V=4.58m/s Assuming none dimensional cross-sectional area shape factor of 0.168 Then area (A) = = 0.150 = 0.891m The belt width will be determined as follows: Therefore: Required drive power and installed power The required power to operate the driving pulleys will be obtained by using the following PA = FU v = 23.5 × 4 =94 kW Motor Power: Where c is the coefficient and it is calculated as follows This is obtained using the following graph that has been plotted which has c as a functional of rent of conveyor. It can also be obtained using the following formula C = 0.85 + 13.31L-.576 for 10 < L < 1500 m C = 1.025 for 1500 < L < 5000 m Resistance due to Empty Belt: Assume 152mm Dia Rolls with single return side idler roll sets: Thus, from appendix = 71 B Where B is the belt width = 71 x = 73.806kg/m Also Lg = 40m/cos45= 52.6m Fully Loaded Resistance to Convey Material Horizontally: Assume: Slope Resistance: H=C sin + (B+2C cos) H=20sin o+ (30+2x20 cos) = 40m Therefore: C = 1.025 This value of will be used in the power equation. PA = FU v = 151.92× 4.58 =695.77kW Installed Power: Total Tension Distribution It is important that the tension F2 is sufficient to provide a corresponding value at the belt sag is within the prescribed maximum value. Two criteria need to be met: Minimum value to prevent drive slip: = FU CW = Lagged drive pulley is 0.4 and radians is 4.19 Thus, CW = = 0.23 Pulley Diameters Minimum drive pulley diameter = 0.8 m minimum Tail pulley = 0.8 m Snub and take-up pulley diameters = 0.75 m minimum Summary i) Conveyor: To carry coal = 810 kg/m3 Incline 1 in 10 L = 2850 m H = 40 m Throughput: 1000 tonne/hour ii) Belting: RN 200 – Rayon Warp, Nylon Weft Carcass Width = 0.8 m Cover thickness = 4 mm Belt mass = 12.5 kg/m iii) Required power: PA = FU v = 23.5 × 4 =94 kW Motor Power: iv) Idlers: 3 Roll system for carrying idlers with Tough angle = 35 Idler diameter = 127 mm Carrying idler spacing = 1.5 m Return idler spacing = 3.0 m v) Tensioning device: Counterweight system: Weight required = 2056 tonne vi) Pulley diameters: Driving D = 0.8 m minimum Tail D = 0.8 m Snub and take-up pulley D = 0.63 m vii) Conveyor Speed: V = 4.58m/s Overall design and velocity profile through hood and spoon Hood Ro = 1.8m, Bi = 1.7m, Bf = 1.6m Vert. Section: L = 0.6m, Bf = 0.8m Spoon Ro = 2.4m, Bi = 1.0m, Bf = 0.8m Delivery Conveyor Head Pulley, Hood, Spoon, Receiving Conveyor Hood Ro = 1.8m, Bi = 1.7m, Bf = 1.6m Vert. Section: L = 0.6m, Bf = 0.8m Spoon Ro = 2.4m, Bi = 1.0m, Bf = 0.8m = 350 Set 1300t/hr h = 5 - R sin() = 5 – 2.4 sin 60 = 2.1 x =R(1 – cos()) = 2.4(1-cos 45) = 0.22 y = R sin() = 2.4 sin (30) = 1.01 Where = 8.96 Belt Wear Where Chute Wear = 0.8 Conveyor Motor Selection PA = FU v = 23.5 × 4 =94 kW Motor Power: Table 1 –Caption for table Winch Type Input Power Rating (kW) Cost ($ each) Cost per M-5 50 5000 5000/50 = $10/kW M-8 80 8000 8000/80 = $10/kW M-10 100 10000 10000/100 = $10/kW M-12 125 12500 125000/125 = $10/kW 4 Design Solutions The selected conveyor motor has to produce more than 98.25 kW. In this case we select M-12 in order to have maximum power since the cost is the same. This regression coefficient indicates towards a close association between the two variables. This finding is further reinforced by the value of R squared. Very high value of r squared, 0.997, suggests that variation in the given data of M* is capable of explaining 99.7percent of total variation in other variable around its average value. It implies that the regression model is a good fit in the given data. Coal loading ratio and relative velocity. The graph depicts that when there is a higher solid loading ratio the relative velocity tends to be lower. This means the flow of the materials in the system are affected by the relative within the system The graph below shows that when the pipe length increases the velocity decreases. This means that the distance to be covered affects the speed of transmission of materials. DiscussionofResults and the application of the Streeter model in determining the air and solid friction. Costs Costs per unit Total Conveyer belt 700 40+50 63000 Motor size 12500 Load out bin 100 (0.168x40) 672 76172 The cost is below the required maximum of $82500 5 Recommendation The designed system should have conveyor belt of 90m in length and the pick-up velocity of 4.58m/s, mass flow rate of materials, distance conveying, gas mass flow rate, gas mass flow, gas constant, absolute temperature, pipeline internal diameter, and gas volumetric flow rate was determined. The design was done successfully to understand the methods of flow measurement and the concepts of flow process that happens inside a pipe. Determining the velocities along a conveyor was done by the measurement of pressure heads 6 References Jones, M&Wypych, P2007,Introduction to Pneumatic Conveying. Centre for Bulk Solids and Particulate Technologies, The Universities of Newcastle and Wollongong. Lewin, DR , Seider, WD&Seade, JD2002, ‘Integrated process design instruction’, Computers and Chemical Engineering, vol. 26, no.2, pp. 295-306. Mondie, S 2005, System, structure and control 2004. Oxford: Elsevier-IFAC. Pan, R 1999, Material properties and flow modes in pneumatic conveying.Powder Technology, 104, 157–163. Roberts, A 1999, Review of belt conveyor design procedures. Centre for Bulk Solids and Particulate Technologies, The University of Newcastle, Australia. Williams, KC2008, Dense phase pneumatic conveying of powders: Design aspects and phenomena. Doctoral dissertation, University of Newcastle, Australia. Williams, KC& Jones, MG2003, Classification diagrams for dense-phase pneumatic conveying.Powder Handling and Processing, 15(6), 368–373. Mr Dug Upton. Telephone ===== Black Gold Pty Ltd Facsimile ------ 77 Tinkers Rd Email ===== Chinchilla QLD 4413 26 October, 2014 Peterson Design Engineer 412Ridgwell Road Sidley NSW3333 Dear Sir Conveyor system proposal report The proposed designed system have shown that the you nee 90m of convey belt and motor power of 125kW and this will $ 79172 . This is shown in the report we have attached We have also contacted an invoice for the work we have undertaken to date. Please contact me if you have any queries, or if you would like us to undertake further work. Yours sincerely Chief executive Officer Read More