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shield support. Development of Shield Support Monitoring System (SSMS), which enables
monitoring of roof condition in real time, by monitoring the parameters of shield support,
as well as development of Longwall Mining Conditions Prediction System (LMCPS) for a
prediction of roof fall hazards and a generation of information about indispensable corrective measures, is the PRASS III project objective.
2.4.2 Shield Support Monitoring System (SSMS)
Shield Support Monitoring System (SSMS) includes geometrical parameters of shield support, hydraulic pressure parameters, tip to face distance and new wireless communication
system. SSMS enables monitoring and recording roof support operational parameters in
real time and it is the basis for a development of the Longwall Mining Conditions Prediction System (LMCPS). For monitoring geometrical parameters of powered roof support,
SSMS includes a set of sensors enabling a determination of an absolute position of each
powered roof support component. All the devices of SSMS meet the requirements of the
ATEX Directive.
2.4.3 Longwall Mining Conditions Prediction System (LMCPS)
It is assumed that by monitoring both shield support behaviour (leg pressures, geometry and
tip to face distance) and geotechnical conditions in longwall in real time, warnings can be
given for significant improper shield support behaviour and the formation of roof instabilities, such as roof cavities/falls or shield closure, several hours in advance. This advance warning allows miners to take a preventive action (such as improvement of roof strata stability
by injections or improvement of the shield support behaviour by increase/decrease of leg
pressure, change of shield geometry etc.) which in turn can reduce longwall downtime and
hazards.
Presented scope of work is realized within the PRASS III (Productivity and safety of
shield support) project coordinated by KOMAG.
2.5 Monitoring of gases
An exploitation of deeper seams, while using the existing ventilation systems, forces miners
to limit, and in extreme cases completely eliminate internal combustion engines from work in
these areas. Alternatively, machines with an internal combustion engine can be powered electrically. They are powered from traction or batteries. Mining machinery with battery powered
drive is used more widely. The lead-acid cells emit hydrogen in the charging or recharging
process at specified concentrations, which is an explosive gas. When evaluating the required
ventilation, the concentration of electrolyte gases should be less than 2%, to avoid the risk
of ignition.
Due to the problems mentioned above, KOMAG developed the MONITOR H system
which is simple, safe and reliable. The compact design enables an easy installation in existing
battery cases. The system can be configured to suit user’s individual needs.
The monitoring system enables a continuous measurement of the cell temperature inside
the cell battery compartment and a continuous measurement of the hydrogen concentration
emitted from the battery while charging and recharging. These measurements are made using
two temperature sensors and two catalytic sensors for measuring flammable gases. An important aspect is an ability to measure hydrogen concentration in two ranges – low to 100%
LEL and high above 100% LEL. This measurement method is required due to a need of the
approval for an operation in the potentially explosive areas. An integration of the developed
MONITOR-H system with the battery-operated control system via a suitable relay enables
to:
− protect cells from damage caused by hydrogen emissions and the presence of high
temperatures,
− extend their service life by limiting the adverse effect of their gasification and the presence
of high temperatures,
shield support. Development of Shield Support Monitoring System (SSMS), which enables
monitoring of roof condition in real time, by monitoring the parameters of shield support,
as well as development of Longwall Mining Conditions Prediction System (LMCPS) for a
prediction of roof fall hazards and a generation of information about indispensable corrective measures, is the PRASS III project objective.
2.4.2 Shield Support Monitoring System (SSMS)
Shield Support Monitoring System (SSMS) includes geometrical parameters of shield support, hydraulic pressure parameters, tip to face distance and new wireless communication
system. SSMS enables monitoring and recording roof support operational parameters in
real time and it is the basis for a development of the Longwall Mining Conditions Prediction System (LMCPS). For monitoring geometrical parameters of powered roof support,
SSMS includes a set of sensors enabling a determination of an absolute position of each
powered roof support component. All the devices of SSMS meet the requirements of the
ATEX Directive.
2.4.3 Longwall Mining Conditions Prediction System (LMCPS)
It is assumed that by monitoring both shield support behaviour (leg pressures, geometry and
tip to face distance) and geotechnical conditions in longwall in real time, warnings can be
given for significant improper shield support behaviour and the formation of roof instabilities, such as roof cavities/falls or shield closure, several hours in advance. This advance warning allows miners to take a preventive action (such as improvement of roof strata stability
by injections or improvement of the shield support behaviour by increase/decrease of leg
pressure, change of shield geometry etc.) which in turn can reduce longwall downtime and
hazards.
Presented scope of work is realized within the PRASS III (Productivity and safety of
shield support) project coordinated by KOMAG.
2.5 Monitoring of gases
An exploitation of deeper seams, while using the existing ventilation systems, forces miners
to limit, and in extreme cases completely eliminate internal combustion engines from work in
these areas. Alternatively, machines with an internal combustion engine can be powered electrically. They are powered from traction or batteries. Mining machinery with battery powered
drive is used more widely. The lead-acid cells emit hydrogen in the charging or recharging
process at specified concentrations, which is an explosive gas. When evaluating the required
ventilation, the concentration of electrolyte gases should be less than 2%, to avoid the risk
of ignition.
Due to the problems mentioned above, KOMAG developed the MONITOR H system
which is simple, safe and reliable. The compact design enables an easy installation in existing
battery cases. The system can be configured to suit user’s individual needs.
The monitoring system enables a continuous measurement of the cell temperature inside
the cell battery compartment and a continuous measurement of the hydrogen concentration
emitted from the battery while charging and recharging. These measurements are made using
two temperature sensors and two catalytic sensors for measuring flammable gases. An important aspect is an ability to measure hydrogen concentration in two ranges – low to 100%
LEL and high above 100% LEL. This measurement method is required due to a need of the
approval for an operation in the potentially explosive areas. An integration of the developed
MONITOR-H system with the battery-operated control system via a suitable relay enables
to:
− protect cells from damage caused by hydrogen emissions and the presence of high
temperatures,
− extend their service life by limiting the adverse effect of their gasification and the presence
of high temperatures,