JNTU
JNTU B.Tech II MINE ENVIRONMENTAL ENGINEERING - I Previous Question Paper (May - 2019 - R16)
Note: This question paper contains two parts A and B. Part A is compulsory which carries 25 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit. Each question carries 10 marks and may have a, b, c as sub questions.
Part A
List the inflammable mine gases.
Answer
The primary inflammable mine gases are methane (CH4), hydrogen (H2), and carbon monoxide (CO).
Explain the effect of breathing air deficient in oxygen.
Answer
Breathing air deficient in oxygen leads to hypoxia. Symptoms include increased breathing rate and heart rate at 15-17% oxygen, dizziness and headache at 10-12%, and unconsciousness or death within minutes when oxygen levels drop below 6-8%.
List the effect of heat and humidity on the miner.
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State the effects of regulator on mine ventilation.
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List the factors for selection of a mine fan.
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Define the laws of mechanical ventilation.
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Define the term Ascensional and Descensional Ventilation system.
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List the conditions requiring auxiliary ventilation system.
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List the scope and importance of Ventilation surveys.
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3500 m3 of inflammable gas is locked in a goaf. What Quantity will enter the mine workings if the barometer falls suddenly from 760 mm of mercury.
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Part B
State the chemical, physical, and physiological properties of Methane gas.
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Discuss about the Gas chromatography and its working principle.
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What is the Black damp?
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The analysis of a sample of mine air gives 19.75% O2; 77.95% N2; 0.4% CO2 and 1.9% CH4; Determine the percentage and composition of black damp in the same?
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At a Certain colliery, the volume of air is 20 m3 per min. and the fan drift Water gauge is 50mm. What is the equivalent Orifice of this mine?
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Sketch and Describe a ventilating door with a regulating shutter in it?
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Describe the salient features of kata thermometer.
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A mine has three separate underground airways connected in parallel across the bottoms of two shafts. The resistances of these airways are 100, 160 and 250 N s2m-8 respectively. If the D.C shaft, U.C shaft and fan drift offer resistance of 20, 30 and 10 N s2m-8 respectively, Calculate the total resistance of the mine. If the fan-Drift Water gauge is 4000 pascal, what Quantity of air would flow through the whole mine and through each split.
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State the characteristics of Natural Ventilation system.?
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Describe the constructional details of Backward bladed centrifugal fan and function of each part and drive?
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How to determinate of Direction and Intensity of Natural ventilation system?
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Calculate the pressure developed by a back ward-bladed centrifugal fan having the following specifications: Fan diameter = 4m; RPM = 300; Blade angle = 400; Velocity = 4 m/s; manometric efficiency = 70% Take density of air as 1.2 Kgf/m3
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Explain the term “Diffusers” with sketch.
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Explain the system of auxiliary ventilation under the Single Heading situation with ducting.
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Explain the Homotropal and Antitropal ventilation system?
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A mine fan running at 300 rpm delivers 150 m3/s of air at a pressure of 900 pa, Fan and motor efficiency are 75% and 90% respectively. If the fan speed is reduced to 250 rpm. Calculate the saving electrical power input to the motor in Kw?
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Draw a simple layout of Air distribution in Long wall workings panel?
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Illustrate with sketch ventilation of development openings in block caving ventilation system for the mine?
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1.25m3 of CO has been produced by blasting in a heading 2.5×3m in cross-section and 50m long. Calculate the quantity of fresh air to be circulated to the heading per second in order to dilute the CO to a safe concentration of 50 ppm in 5 minutes.
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