Mine Ventilation Examination Review PDF

Mine Ventilation EM Board Examination Review 1 Outline I. History of Mine Ventilation II. Properties and Behavior of Air III. Mine Gases and Standards IV. Mine Ventilation System and Controls V. Mathematical Applications in Mine Ventilation...

Mine Ventilation EM Board Examination Review 1 Outline I. History of Mine Ventilation II. Properties and Behavior of Air III. Mine Gases and Standards IV. Mine Ventilation System and Controls V. Mathematical Applications in Mine Ventilation 2 I. History of Mine Ventilation 1 2 3 4 5 6 7 8 9 10 Let us try to Recall: ___Need for a connected ventilating circuit was discovered Link to the Activity: https://forms.gle/sQcnmGXYoRF5XgCt8 ___ Introduction of “Dumb Drifts” ___ John Job Atkinson’s Principles on mine ventilation were put into practice ___ Sending of fireman covered with damped sack cloth to burn out methane became a common method for removing methane ___ Use of analogue computers to facilitate ventilation planning ___ Ability of fire to promote airflow was discovered ___ Use of Steel Flint Mill for illuminating mines ___ Discovery of panel ventilation innovation ___ Invention of Davy Lamp ___ “Theory of the ventilation of mines” was presented by Atkinson to the Institute of Mining Engineers in England 3  I. History of Mine Ventilation Fire and Airflow  Between 4000 and 1200 BC, European miners dug tunnels into chalk deposits searching for flint.  The miners were already making observations of the movements of air in underground passages;  Archaeological investigations at Grimes Graves in the south of England have shown that these early flint miners built brushwood fires at the working faces— presumably to weaken the rock. The Greeks, the Romans, in medieval Europe and during the Industrial Revolution in Britain rediscovered that fire promotes airflow Flint is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start fires. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones 4  I. History of Mine Ventilation Connected Ventilating Circuit  The Laurion silver mines of Greece, operating in 600 BC, have layouts which reveal that the Greek miners were conscious of the need for a connected ventilating circuit. At least two airways served each major section of the mine and there is evidence that divided shafts were used to provide separate air intake and return connections to the surface. Flint is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start fires. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones 5  I. History of Mine Ventilation Early Ventilation Devices  Underground mines of the Roman Empire often had twin shafts, and Pliny (AD 23-79) describes how slaves used palm fronds to waft air along tunnels.  A number of the prints show ventilating methods that include diverting surface winds into the mouths of shafts, wooden centrifugal fans powered by men and horses, bellows for auxiliary ventilation and air doors are seen in Agricola’s book titled “De Re Metallica” Although metal mines were worked in Europe during the first 1500 years anno Domini, there remain few documented descriptions of their operations 6  I. History of Mine Ventilation Faces behind knowledge in mine ventilation Georg Bauer 1. Georgius Agricola is the other name of (ask the class) – Georg Bauer 2. German Geologist, Mineralogist and Metallurgist who wrote two (2) original books in Mineralogy (1546-1548) and a separate book on Metals which is this De Re Metallica that is published in 1556. This became the first great textbook on mining. He was known for his great contribution in Geology, Mining and Metallurgy. He in fact was the one who helped the thriving iron ore mining and smelting community inBohemia in Central Europe. Agricola's De Re Metallica, produced in 1556, is profusely illustrated. 3. De Re Metallica was translated into English in 1912 by Herbert C. Hoover and his wife, Lou. Hoover was a young American mining engineer who graduated from Stanford University and subsequently served as President of the United States during the term 1929-1933. 7  I. History of Mine Ventilation Faces behind knowledge in mine ventilation Agricola included in his book the dangers of: 'blackdamp', air that has made miners suffered from reduction in oxygen content. “miners are sometimes killed by the pestilential air that they breathe” and of the explosive power of 'firedamp', a mixture of methane and air. “likened to the fiery blast of a dragon's breath” Georg Bauer mixture of carbon dioxide and other unbreathable gases that can build-up in mines causing poisoning, asphyxiation, and ultimately death if left untreated 8  I. History of Mine Ventilation Problems in early mine ventilation  From the seventeenth century onwards, papers began to be presented to the Royal Society of the United Kingdom on the explosive and poisonous nature of mine atmospheres Especially during this period 9  I. History of Mine Ventilation Problems in early mine ventilation Used to induce Airflow Used to provide illumination underground Early miners used fire to induce airflow and to provide illumination in mines. We are talking about mines before 18th century. That is before the discovery of: Electric current (Benjamin Franklin); Davy Lamp (Humphrey Davy) and Electric Bulb “Light Bulb” (Thomas Edison) 10  I. History of Mine Ventilation Problems in early mine ventilation The Industrial Revolution brought a rapid increase in the demand for coal. Conditions in many coal mines were quite horrific for the men, women, and children who were employed in them during the eighteenth and nineteenth centuries. Ventilation was induced either by purely natural effects, stagnating when air temperatures on the surface and underground were near equal, or by fire. Early miners used fire to induce airflow and to provide illumination in mines. We are talking about mines before 18th century. That is before the discovery of: Electric current (Benjamin Franklin); Davy Lamp (Humphrey Davy) and Electric Bulb “Light Bulb” (Thomas Edison) 11 I. History of Mine Ventilation Early practices in mine ventilation The first ventilating furnaces of that era were built on surface but it was soon realized that burning coals suspended in a wire basket within the upcast shaft gave improved ventilation. The lower the basket, the better the effect. This quickly led to the construction of shaft bottom furnaces. 12 I. History of Mine Ventilation Early Practices in mine ventilation Oblivious to the extent of the danger, miners would sometimes ignite pockets of methane intentionally, for amusement and to watch the blue flames flickering above their heads. Even the renowned engineer George Stephenson admitted to this practice during the inquiries of a government select committee on mine explosions in 1835. 13 I. History of Mine Ventilation Early Practices in mine ventilation A common method of removing methane was to send a 'fireman' in before each shift, covered in sack cloths dowsed in water and carrying a candle on the end of a long rod. It was his task to burn out the methane before the miners went into the working faces. 14  I. History of Mine Ventilation Early Practices in mine ventilation There are many graphic descriptions of methane and coal dust explosions, the suffering of mining communities, the heroism of rescue attempts and the strenuous efforts of mining engineers and scientists to find means of improving ventilation and providing illumination without the accompanying danger of igniting methane gas. Early miners used fire to induce airflow and to provide illumination in mines. We are talking about mines before 18th century. That is before the discovery of: Electric current (Benjamin Franklin); Davy Lamp (Humphrey Davy) and Electric Bulb “Light Bulb” (Thomas Edison) 15  I. History of Mine Ventilation Start of innovations in Mine Ventilation John Buddle (1773-1843), an eminent mining engineer in the north of England, produced two significant improvements. 1. Dumb Drifts 2. Panel Ventilation Early miners used fire to induce airflow and to provide illumination in mines. We are talking about mines before 18th century. That is before the discovery of: Electric current (Benjamin Franklin); Davy Lamp (Humphrey Davy) and Electric Bulb “Light Bulb” (Thomas Edison) 16  I. History of Mine Ventilation Start of innovations in Mine Ventilation Dumb Drifts (1813) Illustrations by Wabner What it does is drive the return air, laden with methane, bypassed the furnace. The products of combustion entering the upcast shaft from the furnace were too cool to ignite the methane but still gave a good chimney effect in the shaft, thus inducing airflow around the mine. 17  I. History of Mine Ventilation Start of innovations in Mine Ventilation Panel Ventilation (1820) Originally, air flowed sequentially through work areas, one after the other, continually increasing in methane concentration. Which is as much as possible should be avoided to prevent methane concentration meeting the levels at which it becomes dangerous. And this is the same with all gases. 18  I. History of Mine Ventilation Start of innovations in Mine Ventilation Panel Ventilation (1820) In 1820, Buddle originally divided the mine layout into discrete panels, with intervening barrier pillars, to counteract excessive floor heave. However, he found that by providing an intake and return separately to each panel the ventilating quantities improved markedly and methane concentrations decreased. Buddle had discovered, almost by accident, the advantages of parallel layouts over series circuits. The mathematical proof of this did not come until Atkinson's theoretical analyses several decades later. 19  I. History of Mine Ventilation Innovations in Mine Ventilation The mathematical proof of Split Ventilation this did not come until Atkinson's theoretical analyses several decades later through his paper “Theory of the Ventilation of Mine Ventilations” The 1920s saw further accelerated research in several countries allowing improved measurement of airflow and pressure drop for ventilation planning. Atkinson's theory was confirmed in practice and the first successful axial fans were introduced in about 1930. Finally, mines were able to get rid of using fire in promoting air flow underground 20  I. History of Mine Ventilation Innovations in Mine Ventilation In 1943, Professor F. B. Hinsley produced another classical paper advancing understanding of the behavior of airflow by using thermodynamic analyses. Hinsley also supervised the work at Nottingham University that led thepractical use of analogue computers in 1952 to facilitate ventilation planning. Development of ventilation network analysis programs for digital computers in the early 1960-1970s using mainframe computers. A shift to desk-top computers and corresponding programs were developed in 1980s The years around the turn of the century saw working conditions in mines coming under legislative control. Persons responsible for underground mining operations were required to obtain minimum statutory qualifications. 21  I. History of Mine Ventilation Early method of illuminating mines A crisis point was reached in 1812 when a horrific explosion at Felling, Gateshead, killed 92 miners. In 1800, the quest for a safe form of illumination went on through. Some of the earlier suggestions made by scientists of the time, such as using very thin candles 1. ,which appear quite ludicrous to us today. This is used to produce a continuous shower of sparks in order to provide some illumination for the work place of a miner. The instrument was deemed safer than a candle but the light it produced was poor, intermittent, and still capable of igniting methane. Great Britain is the official collective name of of England, Scotland and Wales and their associated islands 22  I. History of Mine Ventilation Early method of illuminating mines One of the more serious attempts was the steel flint mill invented in 1733 by Carlisle Spedding, a well known mining engineer, again, in the north of England. This device relied on a piece of flint being held against a rapidly revolving steel wheel. The latter was driven through a gear mechanism by a manually rotated handle. Early miners used fire to induce airflow and to provide illumination in mines. We are talking about mines before 18th century. That is before the discovery of: Electric current (Benjamin Franklin); Davy Lamp (Humphrey Davy) and Electric Bulb “Light Bulb” (Thomas Edison) 23  I. History of Mine Ventilation Early method of illuminating mines With the help of local clergymen, a society was formed to look into ways of preventing such disasters. Contact was made with Sir Humphrey Davy, President of the Royal Society, for assistance in developing a safe lamp. Davy visited John Buddle to learn more of conditions in the mines. As this was well before the days of electricity, he was limited to some form of flame lamp. Within a short period of experimentation he found that the flame of burning methane would not readily pass through a closely woven wire mesh. The Davy lamp had arrived in 1815 Miners also used the Davy lamp as a gas detector; in the presence of flammable gases, the lamp's flame grew in height and became more blue. The Davy lamp was also used to signal a lack of oxygen, as its flame would extinguish before the lack of oxygen posed a threat to miners 24  I. History of Mine Ventilation Edison Safety Mining Lamp Improvements in illuminating mines Electromagnetic induction by Michael Faraday (principles behind electric motor and generators) Electric light bulb (1878/9) Thomas Edison The early years of the 20th century were some of the deadliest years in the recorded history of mining in the United States as the demands of an industrializing society created increased demands for coal. In 1909 20 coal mine disasters were recorded, the most on record. In 1910, 25 mine disasters (metal/nonmetal and coal) were recorded. The Monongah Coal mine in West Virginia was the site of the largest coal mine disaster in U.S. history in 1907 with 362 deaths recorded. This disaster prompted Congress to create the U.S. Bureau of Mines as an attempt to improve working conditions across the country. It was these mounting disasters that prompted mine engineer John T. Ryan Sr. and George H. Deike to found the Mine Safety Appliances Company (MSA) in 1914. They enlisted Thomas Edison to help them create a dependable and safe electric cap lamp. Electricity had been available in homes for years, but the application of electric lighting in mines was a harder proposition due to the extensive wiring costs. Edison with his Lamp (Photo: Edison National Historic Site) 25 The solution to this problem was a rechargeable battery pack designed by Edison. Then finally, use of fire for either inducing air flow or in providing illumination has already been put to an end. 25 I. History of Mine Ventilation 1 2 3 4 5 6 7 8 9 10 Going back! ___Need for a connected ventilating circuit was discovered Link to the Activity: https://forms.gle/p1H1SJtgo8Jr3mHo6 ___ Introduction of “Dumb Drifts” ___ John Job Atkinson’s Principles on mine ventilation were put into practice ___ Sending of fireman covered with damped sack cloth to burn out methane became a common method for removing methane ___ Use of analogue computers to facilitate ventilation planning ___ Ability of fire to promote airflow was discovered Prizes: ___ Use of Steel Flint Mill for illuminating mines 1st – 100 2nd – 50 ___ Discovery of panel ventilation innovation 3rd - 25 ___ Invention of Davy Lamp ___ “Theory of the ventilation of mines” was presented by Atkinson to the Institute of Mining Engineers in England 26 I. History of Mine Ventilation 1 2 3 4 5 6 7 8 9 10 Going back! ___Need for a connected ventilating circuit was discovered ___ Introduction of “Dumb Drifts” ___ John Job Atkinson’s Principles on mine ventilation were put into practice ___ Sending of fireman covered with damped sack cloth to burn out methane became a common method for removing methane ___ Use of analogue computers to facilitate ventilation planning ___ Ability of fire to promote airflow was discovered ___ Use of Steel Flint Mill for illuminating mines ___ Discovery of panel ventilation innovation ___ Invention of Davy Lamp ___ “Theory of the ventilation of mines” was presented by Atkinson to the Institute of Mining Engineers in England Back 27