• The use of numerical fluid mechanics for modelling of heat exchange in a cooler of arm of high power long wall shearer
  GICALA B., TARKOWSKI A.
• Laboratory tests of powered-roof support in the aspect of meeting the requirements included in Enclosure No. 4 to a Decree of Ministry of Economy dated 28th June 2002
  MADEJCZYK W.
• Experimental verification of FEM model of hydraulic leg with gas accumulator
  MAZUREK K., SZWEDA S.
• Example of using the measuring signals from a monitoring system for analysis of load of longwall shearer’s drives
  JASZCZUK M., KOTORC R.
• Air-and-water spraying as a new method to control dust and methane hazards, which is used in Polish longwall shearers and road headers
  PROSTAŃSKI D., BAŁAGA D., ROJEK P., SEDLACZEK J.
• Decomposition in control systems of hard coal mine processing plants
  FIRCZYK W.
• The use of additional vortex of sucked stream for creation of characteristics of impeller pump
  MIKOŚ M., KALUKIEWICZ A., KARCH M.
• Reduction of above-standard emission of noise from fans of high power
  PIERCHAŁA M.
• System for monitoring of environmental technologies
  JEDZINIAK M., KRUPANEK J.
• Assessment of services’ quality by evaluation of customer’s satisfaction
  ZAJĄC R., MALCZYK S.

The use of numerical fluid mechanics for modelling of heat exchange in a cooler of arm of high power long wall shearer

GICALA B., TARKOWSKI A.
The method of modelling heat and fluid flow in heat exchanger of cooling system for high power cutting longwall shearers was presented in the paper. The Computational Fluid Dynamics method was used to simulate the flow and temperature fields. Temperature of oil and cooling water at outlet and power of heat exchanger were also calculated. Modeling results were verified experimentally. All calculations were made by using Fluent Software version 6.3. Modelling results showed good uniformity with experimental results.

 

Laboratory tests of powered-roof support in the aspect of meeting the requirements included in Enclosure No. 4 to a Decree of Ministry of Economy dated 28th June 2002

MADEJCZYK W.
Laboratory tests of powered-roof support in the aspect of meeting the requirements included in Enclosure No. 4 to a Decree of Ministry of Economy dated 28th June 2002 were presented in the paper. These tests are significant component of assessment of technical condition of powered-roof support.

 

Experimental verification of FEM model of hydraulic leg with gas accumulator

MAZUREK K., SZWEDA S.

Deviations of the amounts determined experimentally from the corresponding amounts determined numerically were analyzed using the results of measurements made at the stand test and results of numerical calculations made with the use of FEM model of hydraulic leg with gas accumulator. The following possible reasons of differences between the results of measurements and results of computer simulation were distinguished: neglection of frictional forces between moving parts of leg in numerical model as well as assumption of ideal gas model for description of changes of gas states in accumulator chamber. The possibilities and purposefulness of modification of numerical model were analyzed

 

Example of using the measuring signals from a monitoring system for analysis of load of longwall shearer’s drives

JASZCZUK M., KOTORC R.
A possibility of using the operational characteristics, which present a changeability of parameters characterizing the load condition of longwall shearer along the longwall face, was described in the paper. The operational characteristics can be helpful to determine the longwall sections at which there are higher cutting resistances.

 

Air-and-water spraying as a new method to control dust and methane hazards, which is used in Polish longwall shearers and road headers

PROSTAŃSKI D., BAŁAGA D., ROJEK P., SEDLACZEK J.

Already known foreign solutions of air-and-water spraying with the use of compressed air, which are developed for longwall shearers and roadheaders, were shortly discussed in the paper. Then the newest original developments, which were realized at the KOMAG Mining Mechanization Centre, were presented. They are designed for fighting against methane and dust hazards in workings mined by longwall shearers and roadheaders. The process and results of these solutions as well as present state of their implementation were given.

 

Decomposition in control systems of hard coal mine processing plants

FIRCZYK W.
State-of-the-art technology provides new possibilities as regards process estimation for local and central control systems. “Virtual measuring tools”, which are based on state-of-the-art software solutions and which are universal at relatively simple method of their manufacturing, can for example be used for this purpose. They can be very useful in solving the problems of local control and diagnostics in technological nodes of processing plants, without interfering in operation of central control room.

 

The use of additional vortex of sucked stream for creation of characteristics of impeller pump

MIKOŚ M., KALUKIEWICZ A., KARCH M.
Part of results of tests on the possibility of monitoring the shape of flow-and-power characteristics of impeller pump, by active impacting on a sucked stream with determined amount of liquid taken from the pumping area, was presented in the paper. Obtained results show that there is a possibility of using a described method for conducting the constant-pressure regulation of pumps’ efficiency in the field of operation below nominal efficiency, where the pump usually operates at low efficiency.

 

Reduction of above-standard emission of noise from fans of high power

PIERCHAŁA M.
Noise is a harmful factor which has an unfavourable impact on all living organisms. The necessity of noise reduction results from this fact and from formal-and-legal requirements developed on this basis. Ventilation systems and fans are one of the most significant sources of noise, taking into account the size of population exposed to them. These sources are of wide impact frequency spectrum, considerable level of acoustic power, as well as continuous character of operation. Limitation of above-standard noise emission from each source should be conducted on the basis of model tests, due to which a real selection of both material and geometrical features, as well as determination of their impact on effectiveness of reduction factor, are possible. The main noise sources in ventilation systems, which can be met both in the area of power objects, mines’ surface and underground mine workings, were described in the paper. Shortened methodology of tests, which objective is to reduce the above-standard noise emission to the environment and at the workplaces, were presented, as well as different designs of passive means for noise reduction were presented and their design features were described.

 

System for monitoring of environmental technologies

JEDZINIAK M., KRUPANEK J.
Formal bases, assumptions and objectives of a system for monitoring of environmental technologies, which will collect information on a development of these technologies in Poland, were discussed in the paper. A principal design of the system and principles of classification of technology as environmental technology, with an environmental division into sectors and sub-sectors, were presented in the paper.

 

Assessment of services’ quality by evaluation of customer’s satisfaction

ZAJĄC R., MALCZYK S.
Products and services, which are present on the market, become more and more similar to each other as regards quality of materials, technologies and even price. That is why they do not play a key role in the “market competition”. Relationships among the customers, which are built by a proper system of information, customer service and care, are the factor which decides about competition with other companies. Tendencies present in enterprises’ activities prove the thesis that the quality and marketing are undoubtedly two domains which penetrate each other.