Source of information: http://fgtu.donntu.ru/kot/nikolin.htm
Way of the unceasing forecast to dangers dead-end partial surge of layer, founded on measurement of the separation of the gas from bore holes and output of bore dust.
This way is designed, practised and is broadly used on mine east and north pool of the country. Essence his is briefly reduced to following:
1. The checking bore holes by diameter 4,2 centimetres , so ke either as in Donbasse, bore by turns. The length of the first interval forms 0,5 and, but all following - 1 metre. The first interval of the bore hole bore the diameter 5,5 centimetres for installing the meter of dust; the second interval - 0,5...1,5 metres and the following -a diameter 4,2 centimetres through channel of the meter of dust. Length of the boring second and each following interval must form 2 minutes.
When boring second and the following interval by means of barbells measure output of bore dust. After completion of the boring second and the following interval by means of barbells, separating bored interval from previous, and meter of the separation of the gas measure the initial velocity of the separation of the gas. The forecast to lead on graph. For initial take the velocity of the separation of the gas, measured in 2 minutes after completion of the boring the interval. The pressure on cuffs must form not less 0,2. At measurement of the initial velocity газовыделения with the second interval meter dust extract from bore hole.
Similarly measure the initial velocity of the separation of the gas and output of bore dust on length of the second checking bore hole. After completion of the observations on maximum importances of the initial velocity of the separation of the gas and output of bore dust on length of each bore hole by means of graphics right in забое production value the danger of the zone of the layer.
2. At estimation of the dangers by crossed production of the zone of the layer for each checking bore hole separately on horizontal axis graphics postpone measured maximum importance of the output of bore dust, but on vertical - maximum importance of the initial velocity of the separation of the gas and through these importances conduct vertical and horizontal line. If cross point these line for one ie two checking bore holes is situated above to ruler, that considers that dead end of the production fell into dangerous zone. Work on undertaking the production must be discontinued. The most further undertaking the production is permitted with using the way of the prevention surge coal and gas with estimation of his efficiency and execution action on safety working.
If cross point specified direct line on graph for every two checking chinks is found below ruler, consider that dead end of the production is found in safe zone.
If after boring the first checking bore hole is installed that lava of the production fell into dangerous zone, that second checking bore hole do not bore.
3. The checking bore holes by length 5,5...6,5 metres bore through each 4...5 metres of the moving the lava by manual drill with use the component bore barbells from winding steels. If checking bore holes on specified depth to bore does not manage, is allowed reduction of the length of the checking bore holes when increase the frequency of their boring from calculation that remaining length of the bore holes was not less 1,5 metres.
If boring the checking bore hole on the first metre is measured big initial velocity of the separation of the gas and output of bore dust, on which finding of the lava is fixed by means of graphics in dangerous zone, the most further deepenning the bore hole and specified measurements possible not to continue.
4. When undertaking the production on whirlled or tilted layer one checking bore hole bore on axis of the production horizontally, but the second - aside uprising the layer from calculation to at achievement of the marked length of the bore hole end his was situated on 1,5 metres above sidebar of the production. When undertaking the tilted production on direct layer checking bore holes will be in walls of the production with such calculation that end of the bore holes were situated on distance 2 metres from sidebar of the production. When undertaking the tilted production on under - stratum of the powerful horizontal layer one checking bore hole bore on axis of the production, but the second - with ascent to aside roofings of the layer from calculation to at achievement of the marked length end her was situated on 1,5 metres above sidebar. When undertaking the tilted production on upper layer of the powerful horizontal layer second checking bore hole bore with slopping aside ground of the layer from calculation to at achievement of the marked length end bore holes was situated on 1,5 metres below sidebar of the production.
When undertaking the tilted production from top to bottom on whirlled or tilted powerful layer one checking bore hole bore on axis of the production, but the second aside roofings of the layer when undertaking the production on under-stratum or under углом aside ground of the layer when undertaking the production on upper layer. The end of the second bore hole is situated on 1,5 metres accordingly above or below sidebar of the production. In all events distance between mouth of the checking bore holes take 1...1,5 metres.
5. On top-down checking bore hole possible to value the danger a surge only on initial velocity of the separation of the gas without measurements of the output of bore dust.
At appearance sign, indicating that lava of the production was beyond the scope of dangerous zone or deleted on distance not less 25 metres from breach, check the danger of the zone of the layer. For this install the checking area by extent 20 metres, within which through each 4...5 metres moving the lava of the production in specified sequences renew the measurements to initial velocity of the separation of the gas and output of bore dust on length of the checking bore holes. The Actions on prevention sudden surge canceal. Hereon lavas begin to move the short step at the speed of not more 1 and in change with erection time crepe to lava. Can be provided as well as the other actions on provision of safety working in ed to lava.
But when the question is dangerous on surge of the gas on layer, situation vastly worse. Increase the output of bore dust can occur not only when increase the tension, but also when boring the bore holes in weak coal layer, pack of the layer, when crushing of coal in bore hole will promote both gas in layer, and methane in bore hole to production.
The experiments were organized on 5 mines, which were developed the most dangerous layers on surge. The methods of the undertaking experiment at most forgive;pardon and is concluded in following. In production toward his undertaking bored the bore hole by length 5 metres and diameter 4,2 centimetres. Boring gradual: after completion of the boring of each metre of the bore hole was defined weight of bore dust. Hereon beside on distance approximately 0,5 metres bored second, parallel first bore hole, in the same way executed the measurements. Obviously that factor was firm, he must be alike for both bore holes. However in most cases picture was got inverse. She has brought about conclusion that factor output dust for gas layer can be not referred to firm, reliable and so is not recommended his use at development of the way of the forecast to dangers surge layer.
The literature
1. Nikolin V., Alexander S. The theory surge and forecastings dangers of emissions. - 1989.
2. The bases to theories sudden surge coal, sorts and gaza. - 1978.
3. Nikolin V., Balichenko I., Simonov A. Fight with surge of coal and gas in shahtah. - 1981.