#2 Laboratory Investigation 2 -pressure-velocity /Quantity survey
RSE3030 – Mine Ventilation | 1 INTRODUCTION Ventilation measurements are needed to ensure effective, efficient and economic ventilation. They include: Air velocity and quantity Ventilation pressures Air quality (including temperature and gas concentrations) Ventilation surveys are needed for planning improvements and changes as well as spot checks to assess system status. They are also needed to check, confirm or correct the results of calculations of pressure losses. AGENDA The agenda for this lab is to conduct a survey of the pressure and velocity/quantity for the ventilation rig. Measurements will be collected to determine the velocity and quantity of air entering the ventilation rig as well as the pressure drop along the rig. In writing your report, you will need to compare calculations of the expected pressure drop with the measurements collected from the survey. Data will be collected at fan pressures of: 500 Pa then 750 Pa then 250 Pa. (This will involve adjusting the fan knob, record the voltage and amperage when set – this could be helpful when thinking about the fan curve later) RSE 3030 Mine Ventilation – Lab 2– Pressure-Velocity/Quantity Survey 2019 RSE3030 – Mine Ventilation | 2 Measurements: Fan pressure (Dwyer series 475 Mark III Handheld Digital Manometer) Dry bulb and wet bulb temperature as well as barometric pressure.* Anemometer - measure the air velocity into the rig. The Pitot tube (TSI Airflow PVM620 micro-manometer) - measurements at multiple rig locations. Trailing hose pressure differences (tubes and TSI Airflow TA-465P multi-function anemometer) * Needed to calculated true density of air dry airwater wet air water dry air water dry air water dry air nn M M M n n n n a air d 1p m RT v RSE 3030 Mine Ventilation – Lab 2– Pressure-Velocity/Quantity Survey 2019 RSE3030 – Mine Ventilation | 3 REPORT FORMAT Introduction – 5 o Briefly summarise report and briefly cover background information Objective – 10 o Be sure to include initial thoughts on what the result may/ should be, a hypothesis if you will. Instruments – 5 o What did you use over the course of the lab, be specific? o Instrument manufactures, models, ranges and uncertainties Procedure – 5 o What steps did you follow/ implement to complete the lab measurements? o Could I repeat the lab again in a year given what I have written down? Data collected – 10 o Just a brief presentation/ discussion of the data collected o Describe what is shown in the tables/figures Data Analysis – 30 o What does the data mean? The basic point o Here is where you will perform the needed calculations, either in whole or as a sample and present averages. o What are the uncertainties in the measurements – how do they affect calculated values? Conclusions – 30 o Did the "experiment meet the hypothesis? If not Why not? o What are some possible sources of error (if any)? References/ Appendix – 5 o Are all references included with enough information to find the reference and formatted appropriately? o Are the appendix materials adequately labelled and detailed? Table 1 Distance of each measurement point to the fan Measurement point Distance to fan (m) Duct diameter (m) SP3 0.2 0.2 SP5 4.36 SP6 6.96 SP7 9.82 SP8 11.32 SP9 14.4 0.16 SP10 16.87 SP11 17.51 SP12 18.98 SP14 22.3 SP15 24.9 SP16 26.9 VP1 2 0.2 VP2 5.06 VP3 11.67 VP4 15.57 0.16 VP5 20.28 Table 2 Psychrometric properties of air in the lab room Dry-bulb temperature （°C） Wet-bulb temperature (°C) Barometric pressure (kPa) 20.25 15.5 101.16 Table 3 Setting of different fan pressure and measured air velocity by vane anemometer Fan pressure (Pa) 485 354 220 Velocity measured at fan (m/s) 8.21 7.68 5.51 Table 4 Static pressure measured at each point under different fan pressure conditions Measurement point Fan pressure (Pa) 485 354 220 SP3 460.8 334.1 200.5 SP5 441 311.4 189.9 SP6 435 304.8 186.8 SP7 262 186.3 117.1 SP8 325 231.2 143.3 SP9 253.5 178.1 114.2 SP10 238.4 165.5 103.2 SP11 230 158.6 98.6 SP12 219.1 150.4 94.1 SP14 172 118.1 74 SP15 152 107.1 66.1 SP16 109.8 70.6 44.2 Table 5 Velocity pressure measured at each point under different fan pressure conditions Measurement point Fan pressure (Pa) 485 354 220 VP1 38 34 20.5 VP2 39 32.6 21 VP3 37.5 33.4 20.9 VP4 92 84 47.8 VP5 91 83.2 49 Anemometer Pitot tube Acrobat Distiller, Job 3 P.A. HILTON LTD. EXPERIMENTAL OPERATING AND MAINTENANCE MANUAL VENTILATION TRAINER B500 B500M/E/2/003 JAN 96 (i) POLICY STATEMENT After Sales Service We, P.A. Hilton Ltd., attach considerable importance in being able to retain the confidence and goodwill of our clients in offering an effective after sales service. Every effort is made to answer clients correspondence promptly and to provide a rapid follow up of spares and replacement parts by maintaining comprehensive stocks of components usually available ex-stock. Should our clients encounter any difficulty in operating or maintaining a Hilton product we would ask that as a first step they contact the Hilton representative in their country or, in the absence of a local representative, write direct to P.A. Hilton Ltd. In the extreme case a problem may arise in the operation of equipment which could seriously disrupt a teaching or research schedule. In such circumstances rapid advice from the manufacturers is desirable and we wish our clients to know that Hiltons' will accept from them a transfer charge telephone call from anywhere in the world. We ask our clients to treat this service as an emergency service only and to use it sparingly and wisely. Please do be aware of the time differences that may exist and, before making a telephone call, make notes of the problem you wish to describe. English is a preferred language. Our telephone number is "Romsey (01794) 388382" and the telephone is normally manned between 0800 and 1700 hrs GMT every day. Advance notice of an impending telephone call by Fax would be appreciated. Each product manufactured by P.A. Hilton Ltd., is tested under operating conditions in our permanent installations before despatch. Visitors to Horsebridge Mill are encouraged to operate and evaluate our equipment with initial guidance from a Hilton engineer. (ii) INDEX Page SCHEMATIC DIAGRAM - Part 1 1 - Part 2 2 - Part 3 3 NOMENCLATURE 4 INTRODUCTION 5 INSTALLATION AND COMMISSIONING 5 Assembly Procedure 5 Optional Extras 9 Line or Branch Configuration 9 Line Balancing Configuration 10 Branch Configuration (Standard) 11 Assembly of the Air Supply Units 11 Work Station Desk 12 Manometer and Hand Held Anemometer 13 SPECIFICATION 14 Instrumentation 14 Safety 14 Services Required 15 Dimensions 15 DESCRIPTION 16 OPERATION 17 Procedure 17 Measuring Instruments 17 Static Pressure Tapping Points 18 MAINTENANCE 19 Testing and Resetting the RCCB 19 (iii) Cleaning 19 THEORETICAL ANALYSIS 20 The Energy Balance in a System 20 Mass Balance 23 Velocity Pressure 23 Determination of Component and Total System Pressure Loss 25 Fan Characteristics 28 Balancing of the Complete Airflow System 30 Useful Data 30 EXPERIMENTAL PROCEDURE 31 EXPERIMENTAL CAPABILITIES 31 1. Examination of typical components, fabrication,installation and assembly techniques used in air handling systems. 32 2. Investigation of pressure losses in bends, branches, changes of section and over straight lengths of duct, together with the variation of pressure drop with air velocity. 36 3. Determination of the k factor for the pressure loss of components in various configurations. 41 4. Examination of standard types of panel and bag filters and their pressure drop against face velocity. 43 5. Investigation of the fan pressure and volume flow characteristics at various supply voltages. 47 6. Measurement of air flow rate using pitot static traverse, orifice pressure differential and anemometer methods. 50 7. Balancing of air flow distribution in a series of branch system using either main damper of fan speed control for final volume flow setting. 55 WIRING DIAGRAM - 240V 63 110V 64 REFERENCES 65 1 2 3 3 4 NOMENCLATURE Symbol Quantity Unit A Area m² d Diameter m f Dimensionless Coefficient of Friction - g Acceleration Due to Gravity m s-² H Pressure Head in m of fluid m k Pressure Loss Coefficient (a constant) - l Length m m Mass kg p Static Pressure N m-² Q Volume Flow Rate of Air m³ s-1