Show SOME NOTES ON MINE ventilation GIVEN BY AN EXPERT ON THE SUBJECT recently at a meeting of the local section of the A S tit E P W belcher Uel cher mechanical engineer and well informed specialist in mine mille ventilation I and kindred problems presented the following paper mr belcher represents in this field the coppus engineering corporation and various lines of power plant equipment and as such lie he is an authority on the subject of coal and metal mine ventilation ed the science of mine ventilation is now about one hundred years old havin having 6 had its inception in the coal mining districts district s of england and wales incidental with the larger development of coal mining with the growth of steam power As the old mines were from growing necessity developed from surface workings to depth operations accidents and deaths multiplied until parliament had finally to take cognizance of the menace of poorly ventilated mines and about 1840 enacted the first legislation on recard covering the question of ventilation pennsylvania was the first state in the united states to enact legislation covering the ventilation of coal mines As early as 1858 the miners of pennsylvania petitioned the legislature for laws governing the mining in of coal similar to those enacted in great britain this petition received little attention until after the great disaster at avondale pa in 1869 which was directly responsible for an act of the pennsylvania state legislature passed in 1870 for the purpose of creating a state board of inspectors to look to the safety and health of the miners and to the property of the operators in the state of ohio at about the same time similar legislation was enacted making the inspection spec tion of mines a state function importance of ventilation in operating costs As coal and mineral deposits are worked out and operators are forced to work at greater depths the importance of ventilation increases either the cost of the miners products must be increased or more efficient means must be found to meet the new conditions the cost of labor is generally the largest item in the cost of mining ore by underground workings and it naturally follows that any equipment which will increase the efficiency and output of that labor is an economic necessity the efficiency of labor and the labor turnover are vitally effected by the conditions of healthfulness comfort and safety in any property lack of adequate ada quate cooling power in the air makes continuous hard work in restricted spaces a nightmare and cannot fail to seriously effect the miners output fires explosions and noxious noxious gases take their toll of life against all of which good ventilation can and has been successfully pitted the subject of mine ventilation can in a broad general way be divided into two major groups i e main mine ventilation ti through airways shafts and drifts by large units usually located at the surface and secondary or auxiliary mine ventilation through smaller independent units located locate ZI at various points throughout the mine where supply of fresh air is available for distribution to dead ends raises etc the practice in coal mines all coal mines are equipped with main mine ventilating units located and permanently installed at the surface and capable of forcing an adequate supply of fresh air against the resistance of the mine airways through ih all entries and rooms such units are customarily required to be reversible in ill order to 9 guard against emergency conditions such as fires and explosions in nongaseous non gaseous coal mines frequent recourse is had to small auxiliary units at various points in the main ventilating current to pick up fresh air supply and deliver same to remote headings and sweep any accumulations of gas fumes powder smoke dust etc harmful and dangerous to the miners the question of drives for such auxiliary units in the case of coal mines is an important one as there is a certain amount of danger incident to the transmittal of electric current underground where accumulations of coal dust or explosive gases are possible alternating current motors either of the totally type or with all frame openings carefully screened are reasonably safe but there is of course always the danger of short circuits from worn cables or switches and lately there has been consid bable discussion of compressed air as the safest available drive unfortunately unlike metal mines where compressed air air is is extensively used for drilling purposes and transmission pipes laid more or less permanently air is not used to any great extent locally in coal mining properties and hence considerable expense would be involved in installation of air lines and fittings there are however several large coal operators in the eastern states who are now using compressed air driven auxiliary blowers and fans and one or two still using steam driven equipment several well developed and practical lines of compressed air driven blowers and fans are on the market and widely used in metal mining operations and this in the writers opinion offers one of the most prolific fields for improvement in coal mine ventilation as well as in metal mining operations metal mine ventilation many of our larger metal mines where the workings have been carried to considerable depth have installed permanent main mine ventilating units at the surface but as metal mines are usually of the single entry type such developments are necessarily limited to mines having more than one entry or provided with supplementary air shafts or airways leading to the surface or interconnecting with other properties which provide egress for the air currents practically all the larger metal mining operators have recourse to secondary or auxiliary ventilating equipment where the units deliver the ventilating current to remote parts of the workings through galvanized iron or canvas vent pipe or tubing in nearly every case better production has resulted from these provisions and particularly so in in mines where rock temperatures are high the united states bureau of mines has conducted some very interesting experiments along these lines in the property of the anaconda Anal conda copper mining company at butte and at other points and pamphlets are available thereon valuable data is now available until quite recently there has been scant available liter i on the subject of mine ventilation outside of m material ater I 1 al published in the trade catalogs of various manufacturers and some five or six years ago when the writer became specially interested in this subject it was necessary to work up tip from first hand experience aided by such trade information as was then published and appeared reliable a complete set of original data tables and curves and formulae lor for practical use in the field this data has proved useful it in a practical way in solving problems for clients and these set sets are still available to such engineers and operators as may lay desire them for technical purposes upon application and an without obligation in the past year there has been published by processo pro pr lofessor tesso walter S weeks of the university of california a very useful book on ventilation of mines mcgraw hill book OOK company N Y and obtainable from the salt lake mining review and I 1 can commend this work to friends and an ill clients in the mining trade as filling a long needed place and u this particular field the formulation of the principles an laws governing ventilation is given quite clearly and concisely co esely with very good descriptions of measuring devices devic and instruments |