RI 2320 Performance of Fan-Pipe Installations In Metal Mines

The use of shall electrically- driven fans , in conjunction with air- pipe of various diameters is becoming of increasing importance for the ventilation of working places in metal mines through which the general ventilating currents can not be coursed . It will probably continue to increase in importance since the concept that air motion is the most important factor in maintaining comfort in hot ( above 80° F . ) working places is more generally accepted , and as the inefficiency and greater expense of attempting to ventilate such places with compressed air is recognized . Managers of large properties can afford to experiment with fan- pipe installations until types are found that meet their conditions , but managers of shall properties , unless forced to it by extreme conditions , prefer to wait until they can obtain data sufficient to guarantee at least a measure of success from such installations . At present , such data , even in part , are available to only a few (mainly fan manufacturer's representatives , consulting ventilation engineers , and ventilatin engineers employed by large companies ) , and important recent developments are mostly of a confidential nature . One large metal - mining company cooperated with a fan manufacturer in some extensive experimental work on small blowers and found that instead of using stock fans , considerable power economy could be effected and equal quantities of air delivered by use of or 2/3 width fans with small motors rather than using stock fans and larger motors ; it was also found advisable to adopt certain sizes of tubing for certain lengths of run . In fact , many important facts were ascertained in this study , and it is now promised that they will soon be given to the public . It is true that a certain amount of data on industrial installations are available , but such data are only in part applicable to metal -mine conditions , because , until recently , little attention has been given to ventilation in metalmines , and the conditions encountered usually require a greater length of pipe , a more temporary type of construction , and closer attention to temperature control than the ordinary run of industrial installations demands ..