The Birmingham age-herald., 1911-04-10

of the safe mines of America Like Mulga it was equipped with every mooern equipment.
 ErsSine Ramsay, vice president and chief engineer of the Pratt Consolidated company, in detailing the extreme care used in sprinkling the mine at Banner, recently prepared a paper for the oper- ators' association, in which he said
 "The amount of water an air current will take out of mine in cold weather is surprising and startling. At Banner l the ventilating current amounts to 200,- 1 900 cubic feet per minute, and for the purpose of calculation the inlet and out let will be considered of equal volume. 1 From the tables it is found that this vol ume of air when thoroughly saturated and at a temperature of 40 degrees Fahrenheit. will carry into the mine in "A hours about 14,000 gallons of water in the shape of moisture. The same cur rent, heated to the temperature of the mine, say 65 degrees, Fahrenheit, will carry out of the mine about 34,0OO gallons
 thus robbing the mine of 40,O0O gaiions ] each 24 hours. Unless the mine is to be dried out and become dusty this moisture must be supplied to the air current from steam jets. pools of water, hose, sprays | or other means.
 "At Banner it is sought to supply by 1 sprays at least part of this loss. The ,S1 sprays now installed will deliver about 1 30 gallons per hour and with all of them working a total of over 22,00O gallons would be delivered during each "A hours or little more than is taken out by the current. During next winter it is pro-
 posed to even increase the number Of sprays, and with all them working 1t can
 be determined just how successfully they 1 will meet the conditions. At that time l tests should be made to show how near complete saturation is secured and wet and dry bulb thermometer readings sys-
 tematically taken.
 "The Banner shaft mine began opera
 tions October IA, 1904, mining what is known as the big seam, which averages at 1 this point a total thickness of about nine l feet having a top coal, including some | slate of 54 inches, bottom coal of 36 inches with a middle man of about 15 1 inches. The coal is dry and friable, and when machine mined and shot with bitu- infinite only 25 per cent of it passes over 1 an automatically fed shaking screen nav l ing peforations of two and one-half inches | in diameter The daily output runs from l 1009 to 1200 tons. An analysist of the coal shows about 29 per cent volatile mat | ter.
 "The shaft is located near the western outcrop where the seam has a dip to the | southeast, or in other words, into the | field of about 8 per cent. With this dip and with the working places extending ] into the field the mine water drains to- ward the face of the slope and away 1 from the older workings, thus causing them to become dry and dusty in many places.
 Until 1906 the coal was mainly shot on the solid with 3-F black powder. From l then until September, 1908, varying pro- l portions were machine mined. Since 190S practically all coal in headings, air
 courses and rooms has been machine
 mined. All of the under cutting is done
 with Sullivan Long Wall machines, mak- ing cut of five and one-half feet in depth by about five inches. In making
 such a cut in rooms 42 feet wide about 5000 pounds of slack" coal is produced, part of which is very fine~and calculated
 to go a long ways toward supplying the mine and ventilation with the troublesome | and dangerous mine dust The fine coal
 is loaded out along with the other coal. | "As the mine grew in extent and un- der the conditions stated 1t was found that some of the workings contained oust | in such an amount as to demand that 1t | be handled in some way that would re- | move as far as possible the danger rom explosions The mine itself gives off some gas, but not in sufficient quantities
 to make it dangerous, from this source alone with proper ventilation. No safety l1a, hxr tln fra hnC is well established that a small amount | of gas in the air of a mine becomes dan gerous when considerable mine dust Is present.
 with these conditions it was necessary | to do away with the danger, and at first pipe lines were laid to such portions of | the mine as were dry and contained dust. Tees were provided at frequent intervals
 in these pipe lines, so that hose pipes could be connected, and such dangerous places including rooms, were watered sur- l ficiently to dampen and lay the dust. At
 least this was attempted.
 While this plan did much good. it was not found to be sufficiently effective, and especially as the watering prRess with | the hose pipes was not attended to with {, sufficient regularity. The watering with
 the hose was supposed to be done at least once a week. but in many cases 1t was l found not done thoroughly. The pipe lines supplying water for the hose pipes were | connected with the mine pump, used iu | unwatering the mine, and which dis | charged against head of about 150 feet.
 "After finding by experience that this
 plan of taking care of the dust was not | effective and that the hose proposition | by itself was not what the conditions demanded, few sprays made by the | American Moistenng company of Boston
 were put into service and the number in creased from time. to time until there are at present 31 installed.
 ''For some time the water supplying the ! sprays was furnished by the mine pump, previously mentioned, but trouble devel- oped in the fact that the fine sediment | taken up by the pump from the dump and l forced through pipes to the sprays lodged | in the small spray outlets and clogged | them up. To get around this trouble the | connection to the mine pump was aban- l doned and instead one was made to the | reservoir located on the outside and near the shaft At the present all of the water used in the sprays comes from the reservoir, which is supplied from the l,Warrior river and no trouble has been | experienced since with the sprays clogging up. While it adds somewhat to the ex- | pense, as more pumping must be done l from the river to the reservoir and from the mine to daylight there is some recom- | pense for this in the fact that the pipe i lines and nozzles should last longer, as 1 the same corrosive action will not exist. | Sprays connected with the reservoir also have the additional advantage of receiv- | ing a much more uniform and constant supply than is the case where connection is made to the mine pump.
 At the time we experienced the trouble