EXPERIMENT A Parallel Pump Test Rig

Transcription

1 KNC 1101: CHEMICAL ENGINEERING LABORATORY I LABORATORY MANUAL EXPERIMENT A Parallel Pump Test Rig Faculty of Engineering Department of Chemical Engineering & Energy Sustainability Semester 2_ 2013/2014

2 INTRODUCTION Pumps are used in almost all aspects of industry and engineering from feeds to reactors and distillation columns in chemical engineering to pumping storm water in civil and environmental. They are an integral part of engineering and an understanding of how they work is important. Centrifugal pump is one of the most widely used pumps for transferring liquids. This is for a number of reasons. Centrifugal pumps are very quiet in comparison to other pumps. They have a relatively low operating and maintenance costs. Centrifugal pumps take up little floor space and create a uniform and nonpulsating flow. Serial / Parallel Pump Test Rig is specially designed to demonstrate the operating characteristics of centrifugal pump in series, parallel or single pump operation. The training unit operates in close loop. Objective of the Experiment 1) To study the characteristics of single pump operation with variable flow rate and pump speeds. 2) To study the characteristics of pump-in-parallel operation with variable flowrate and pump speeds. Prior Knowledge 1) Fluid dynamics (fluid in motion) 2) Volume-flow measurement Materials and Equipment 1) Serial / Parallel Pump Test Rig (Model: FM 07B) Prepared by Mohamed Afizal Mohamed Amin 2

3 Figure 1(a): Equipment assembly 1) Pump, P1 2) Pump, P2 3) Water Tank 4) Speed Sensor, SP 1 5) Speed Sensor, SP 2 6) Pressure Gauge 7) Pressure Transmitter The unit consists of the followings: a) Dimension The unit has a dimension of 1.10 m (L) 0.65 m (W) 0.70 m (H). b) Interchangable Impeller The unit is delivered with three impellers in total, one with forward curved blades and two with backward curved blades. c) Pumps Two units of Horizontal Single Stage Centrifugal Pump (P1) and (P2) d) Circulation Tank A transparent PVC water tank is provided to supply water to P1 and P2. e) Flowrate and pump head, speed and power indicators. All indicators are displayed in its respective engineering unit. No conversion is required. f) Process piping The process piping is made of industrial PVC pipes. s used are nonferrous to minimize rust and corrosion. Prepared by Mohamed Afizal Mohamed Amin 3

4 g) Selector switch The selector switch allows the selection of system operates either with 1 pump or 2 pumps (series/parallel). h) Digital indicator There are 4 digital indicators located at the front panel for displaying of flow rate, pump head, power and speed indicators. 1. Power indicator: Indicated value is in Watt. 2. Speed indicator: Indicated value is in Revolution Per Minute (RPM). 3. Flow indicator: Indicated value is in Liters Per Minute (LPM). 4. Pressure Indicator: Indicated value is in percentage of the maximum value Pressure Transmitter 1 (PT1) Pressure Transmitter 2 (PT2) Pressure Transmitter 3 (PT3) 0-4 bar (abs) 0-4 bar (abs) 0-4 bar (abs) i) Data Acquisition System The Data Acquisition System consists of a personal computer, software and I/O hardware. The I/O hardware is linked to computer by means of a RS232 communication cable and is connected to the computer with a 9 pin D-Shell connector. Instruments that are permanently installed are turbine flowmeters (FT) for measuring water flow rate, pressure transmitters (PT) for measuring the pump head and a power transducer to measure the motor input power. There are 2 speed sensors to measure pump speed for P1 and P2, respectively. Prepared by Mohamed Afizal Mohamed Amin 4

5 FT PT3 V5 V6 Circulation Tank V2 P2 PT2 V1 V3 PT1 Drain P1 V4 Figure 1(b): Process diagram for Serial / Parallel Pump Test Rig Prepared by Mohamed Afizal Mohamed Amin 5

6 METHODOLOGY A. General Start-up Procedures Before conducting any experiment, it is necessary to do the following checking to avoid any misused and malfunction of equipment. 1. The circulation tank is filled with water. 2. Make sure V5 is in fully close position. 3. Switch on the main power supply. 4. Turn on the main switch on the control panel. Ensure all digital indicators illuminate. 5. Turn on the computer and activate the data acquisition software. 6. Check for the following valve position. Pump Operation Running Pump Fully Open Fully Close Single Pump 1, P1 V1, V4 V2, V3 Parallel Both Pump, P1 & P2 V1, V2, V4 V3 7. Turn on the pump and slowly open V5 until maximum flowrate is achieved. Follow the experiment procedure to determine the desired flowrate. 8. Use the pump speed selector switch to monitor the pump speed. 9. Use the pressure selector switch to monitor the pressure in the pipe. 10. Turn the pump speed controller clockwise to increase pump speed or anticlockwise to decrease the pump speed. B. Experiment 1. Follow the basic procedure as written in A. 2. For first task, ensure that all setting follows the equipment set up. Fully Close Fully Open Variable Parameter Pump ON V2 & V3 V1 & V4 V 5 Pump 1 3. Test the pump characteristics under the following condition and records the data. Maximum motor speed at 3000 RPM; varied V5 opening (Take 5 readings) 4. Repeat step 2. Use following setting Prepared by Mohamed Afizal Mohamed Amin 6

7 Fully Close valve Fully Open Variable parameter Pump ON V3 V1, V2 & V4 V5 Both Pump 5. Test the pump characteristics under the following condition and records the data. Maximum motor speed at 3000 RPM; varied V5 opening (Take 5 readings) C. General Shut-down Procedures 1. Turn off the pump. 2. Make sure valve V5 is in fully close position. 3. Turn off the main switch on the control panel. 4. Shut down the computer. 5. Switch off the main power supply. RESULTS AND DISCUSSION Additional Information: Overall Efficiency Power (fluid) Gravitational Acceleration Volumetric flow rate Pump Head Water Density Pressure unit [P1,P2] is Pascal Unit conversion : 1 bar = Pascal 1. Plot pressure difference pump head (m) versus flow rate in one graph for both settings (single and parallel) condition. 2. Plot efficiency versus flow rate in one graph for both settings (single and parallel) condition. 3. Compare and discuss the pump performance between single pump and series pump operation. Prepared by Mohamed Afizal Mohamed Amin 7