US906872A - Method of preventing the liberation of fire-damp. - Google Patents

Description

A; VON GRGLING.

METHOD OF PREVENTING THE LIBEEATION OF FIRE DAMP. APPLICATION FILED MAR. 16, 1908.

906,872. Patented Dec. 15,1908

UNITED STATES PATENT OFFIU.

ALBRECHT VQN GRijLING; OF VIENNA, AUSTRIA-HTINGARY.

METHOD OF PREVENTING THE LIBERATION OF FIRE-DAMP.

. To all whom it may concem: i

, Be it known that IXALBRECHT VON GRoL 1N0, SDbJGCt of the Emperor of Austria-.

ated at a low atmospheric pressure and flow-.

ing from several places combines to produce catastrophic disasters.

The present invention relates to a method having for itsobject to obviate the said drawback and to attain a relatively satisfactory security in the working of mines. For this purpose according to the present invention the atmospheric pressure in the mines is always maintained on the same height notwithstanding the variations of the exterior atmospheric pressure, the mines being closed from the outer air by means of suitable pit closures of'known construction and the actually existing ventilating means (ventilators, air feeding shafts and ventilating drifts) being retained. The said maintenance of the stationary air pressure in the mines is effected in such a manner that the relation between the quantity of air admitted into the mine in a unit of time by means 'of one, ventilator to the quantity of air exhausted from the mine in the same unit of time by means of a second ventilator is regulated according to the barometric height. In this manner the gas ressure in the mine can be, controlled wit the barometric limits or even beyond the same by the differences in the numberof revolutions of the ventilators.

The working of the ventilators can be actuated by means of a motor of any desired kind and the controllin of the performed work can be effected eit or by hand according to the observed barometric heights or automatically by the variations of the atmospheric pressure.

In order to prevent the escape of fire damp at low barometric height it has already been proposed to feed fres air into the mine by means of a blast ventilator so that the fire dam is being retained in the mine indepen ently from the alterations of the pres.- sure of the exterior atmosphere. Now according to the present invention the action of Specification of Letters Patent. Application filed Mama 16, 1908. Serial m. 421,533.

of the ventilation of the mines.

Patented Dec. 15, 1908.

the blastventilator is supported by means of a suction ventilator, this arrangement presenting the advantage that by differentiating the working of the two ventilators the facility is afiorded to produce in the interior of the i mine quite independently from the condition of the exterior atmosphere pressure of any desired height and consequently depressions; this method could absolutely not be produced by means of one single blast ventilator.

Moreover the em loyment of two ventilating devices of equal output of which each is sufficiently large and powerful to perform by itself if necessary the ventilation of the mine presents the important advantage of afi'ording a mutual reserve of absolute safety. This is of particular importance in consideration of the fact that in the event of explosion occurring-in the interior of the mine blast ventilators are as a rule damaged and put out of work so that precisely in the cases of similar incidents the mine remains without ventilation. Furthermore in the above named known system the tight closure of the air admission pit (that is to say in the present instance the pneumatically closed working pit) may become damaged for some reason or other. If in such case only one single blast vventilator is employed the ventilation of the mine may be either damaged or en tirely sto ped. A similar occurrence must of course be avoided under all circumstances and in such cases the suction ventilator will automatically perform as a complete reserve organ the ventilation of the mine.

A suitable regulation of the number of revolutions of the ventilator affords the possibility to variate at will the air pressure in the mine so that the above mentioned arrangement of blowing ventilators and suction ventilators can also be employed for the urpose of producing an underpressure wit in the.

mine and to suck up by means of this under.

ressure the fire damp from the rock as also rom the old filled up works and to exhaust the same b the admission of fresh air, said operation eing preferably carried out. on non working days. above ground can be constantly submitte to analysis in order to determine the nature The process of closing or reducing the admission opening of the pits for fresh air in order to exhaust the gases of the mine rock by means of a suction ventilator is already The fire damp escaping known but this method afiorded until now the possibility to obtain only most insignifi cant depressions particularly in the caseof extensive sets of a mine. On the other hand this method cannot under any circumstances afford the possibility of increasing the pressure as compared with the exterior atmospheric pressure whenever this may be needed.

As showing a conventional means whereby a method in accordance with this invention can be carried out, reference is had to the accompanying drawings wherein Figures 1 and 2 represent diagrams of the arrangement of one ventilator or of two ventilators respectively at the mouth of air shafts. Fig. 3 represents an arrangement for the automatic controlling of the output of a similar ventilator and Fig. 4 shows a form of execution of the device employed for closing the pit.

In the arrangement according to Fig. 1 air is forced into the air shaft b by means of a forcing ventilator a while a second air shaft 0 serves for the escape of waste air. The exhaust opening of the latter is made of such dimensions as to allow of the flowing ofl of only such quantity of air that corresponds to the quantity of air admitted at b when the ventilator is working with normal velocity. This takes place at a favorable exterior atmos heric pressure which in this case will coinci e with the air pressure in the mine. Whenever the exterior air pressure diminishes the ventilator is made to work more rapidly with greater velocity, whenever the air pressure in the mine is comparatively increased, that is to say it remains the same as before.

In the arrangement according to Fig. 2 air is admitted into the pit I) also by means of a pressure ventilator a, while the waste air is exhausted from the pit c by means of a second ventilator d. In order to maintain constantly in the mine the samedegree of pressure and to avoid almost completely any variations of pressure the suction ventilator can be made to work slower to a suitable extent and the forcing ventilator correspondin ly quicker when the barometer is falling. This controlling of the air ressure in the mines can be efi ected accor ing to the observed barometric heights by suitably regulating the corresponding driving machines (electromotors, steam engines etc.) either by hand or by means of an automatic regulating device actuated by the falling or rising of the exterior air pressure itself.

One form of regulating device is illustrated by way of example in Fig. 3. In the tube of a mercury barometer g with" opencistern are melted in the ends of a number of metallic wires 1' within the limits of the possible variations of the mercury level in the barometer tube; these wires are arranged in juxtaposed pairs superposed one pair above the other so that the mercury as soon as it has reached a certain level will come in contact with the corres onding pair of wire ends and will establish t e metallic contact between the same. The metallic wireslare connected to an electromagnetic apparatus which comes into action as soon as the circuit is closed; the said apparatus has for its object for instance to turn a lever by means of which a resistance inserted in the leads of a dynamo that drives the ventilator is put in circuit or out of circuit. When the barometer is rising the superposed pairs of metallic trical connection and consequently the corresponding resistances 7c of a rheostat h are put into clrcuit or as the case may be out of circuit. When the barometer shows the positionthat is most favorable for the mine that is to say as a rule its highest position all metallic wire ends are electrically connected with each other; I When the mercury column in the barometer tube is falling the connection of the successive wire pairs Will be gradually interrupted so that the corresponding resistances will be successively put into or as the case may be out of circuit. The electrical contact may however be established for good and all by connecting the mercury to a return lead m. The maintenance of a uniform air'pressure in the mine always presu poses that the connection of the interior 0 the mine with the exterior air can be interrupted by means of a closing device. This is efi'ected by means ofv pit closures such as are already known. Fig. 4 shows by way of example a similar closing a device. The top of the it is closed by flap doors p which are raise by the ascending drawing cage 0 and while the latter is in its uppermost position the said flap doors p are replaced by the bottom 1' of the cage so that in this manner the closure of the pit mouth is not interrupted for a single moment. When the ca e is being lowered the aperture is again 0 osed in consequence of the weight of the flap doors p or by some other mechanical means producing the closure of the fla doors. The small a ertures and slits that remain open in sim ar closing devices are but of secondary importance for the purpose aimed at.

The admission or exhaust of air by means of ventilators as above described can be performed according to the particular local circumstances not only through the ventilator pits and the working pits but if required also through the pumping shafts.

What I claim is 1. A method of preventing the liberation of fire damp in mines consisting in maintaining an invariable air pressure of apredetermmed degree in the mine irrespective of barometric variations in the air exterior of the mine by regulating the quantity of air adwires '1, are successively brought into elec-.

mitted into the mine in 5 unit of time rela tive of the barometric variations of the air tively to the quantity of air exhausted from exterior of the mine. the-mine-in the same unit of time. In testimony whereof I'have hereunto set 2. A methodof preventing the hberation my hand in presence of two subscribing wit- 5 offire damp in mines consisting inmaintaining nesses. v

" a stationary air pressure of a predetermined degree by regulating the quantity of air ad- ALBRECHT VON GROLING mitted into the mine in a unit of time rela- Witnesses: tively to the ua'ntity of air exhausted from JosEF RUBURGH,

10 the mine in t e same unit of time irrespec ROBERT W. HEINGARTNER,

v r v r

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