Wyniki wyszukiwania - BazTech

1

Effectiveness of half masks for respiratory health protection in coal mining

Drwięga Andrzej, Williamson Ben, Foster Patrick, Lesiak Krzysztof

Mining Machines

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2021

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no. 3

2--17

EN

An improved procedure is presented for testing the level of respiratory health protection and comfort of half masks currently used in coal mining and similar industries. This will allow companies to make the best choice of such equipment for their workers. Half masks used by one Slovenian (PV) and two Polish (JSW and PPG) coal mining companies were tested in terms of filtering efficiency, especially for PM2.5, perceived effectiveness, comfort and ease of use. Filtering efficiency was determined by analysing filters from masks used in underground operations for the levels and sizes of trapped coal dust particles and by carrying out experiments employing a specially developed laboratory test stand. The latter incorporated a replica human head and a climatic chamber to simulate the humidity of exhaled air during mining activities. To determine the comfort and utility of the half masks, selected miners were asked to fill in questionnaires. The main results of these studies were that, in the interest of miners' health, and for those working in other high dust environments, the quality of the half-mask should be assessed on the basis of workplace and stand tests. These are complementary and both should be included to ensure the correct assessment of the half masks. For the masks supplied by the mentioned mining companies, their filtering efficiency for PM2.5, as determined using the test stand, was excellent at over 99%.

2

A small-size stand for vibroacoustic and durability testing of rolling bearings

Wróbel M., Barczewski R.

Vibrations in Physical Systems

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2017

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Vol. 28

art. no. 2017006

EN

A small-size stand for vibroacoustic and durability testing of rolling bearings is presented in this paper. Main purposes and motivations for building this stand were not only to assist research and development works but also to familiarize students with techniques and methods of rolling bearings diagnosing as well as to improve their skills of assessment of rolling bearings technical condition. The project assumptions of the stand, mechanical construction and architecture of data acquisition and analysis system (hardware and software) are described in this paper. Finally there are conclusions about stand’s capabilities included.

3

Research on tightness loss of belt conveyor's idlers and its impact on the temperature increase of the bearing assemblies

Pytlik A., Trela K.

Journal of Sustainable Mining

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2016

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Vol. 15, iss. 2

57--65

EN

The temperature of idlers' bearing assemblies is the basic indicator of their technical condition. The main aim of this article is to present the impact of decreased tightness of the conveyor belts' idlers which results in the higher temperature of bearing assemblies, which in turn is the main factor influencing their level of durability. This article includes research methodology of idlers, which was designed to determine the direct impact of lower tightness of bearing assemblies, at a determined load, on the temperature of bearing assemblies. Research results are presented in the form of dependence of DT temperature increase, in t time function, and at the determined F radial load. The characteristics set during the tests included the temperature of bearing assemblies and were analysed in terms of the possible or potential risk of bearing assembly seizure. The research carried out showed the significant impact of load on the temperature increase of bearing assemblies. Constant recording of temperature increases and the nature of changes allowed conclusions to be drawn concerning the seizure of bearings or idler's seals. A thermographic (infrared) camera enabled pivotal areas located in the bearing assembly to be determined, which may indicate the seizure, and helped to present thermography images showing the distribution of the temperature in the idler which occurred during testing.

4

Właściwości murów z elementów silikatowych produkowanych w Polsce. Cz. 2. Wytrzymałość muru na ścinanie

Drobiec Ł., Jasiński R., Piekarczyk A.

Przegląd Budowlany

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2013

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R. 84, nr 5

19--25

PL

W artykule przedstawiono wyniki badań wytrzymałości na ścinanie poziome murów z elementów silikatowych pochodzących od krajowych producentów. Przy braku krajowych badań, zasadniczym celem podjętych badań była weryfikacja podanej w Załączniku Krajowym EC -6 początkowej wytrzymałości muru na ścinanie fvko murów z elementów wapiennopiaskowych grupy I z cienkimi spoinami. Artykuł stanowi drugą część cyklu publikacji dotyczących podstawowych właściwości murów z krajowych elementów wapienno-piaskowych. W części pierwszej artykułu opisano badania wytrzymałości na ściskanie, natomiast w części trzeciej przedstawione zostaną wyniki testów murów zginanych.

EN

This paper presents the results of testing of the horizontal shear strength of walls made of silicate elements obtained from Polish manufacturers. Given the absence of national tests, a fundamental goal of the research was to verify the value given in National Annex EC -6 for the initial shear strength fvko for walls built with Group I lime-sand elements with narrow joints. The article appears as the second part of a series concerning the basic properties of walls made of Polish-produced lime-sand elements. The first part described tests of compression strength, and the third part will present the results of tests on walls subjected to bending forces.

5

Durability testing of idlers for belt conveyors

Pytlik A.

Journal of Sustainable Mining

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2013

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Vol. 12, iss. 3

1--7

EN

The main purpose of idlers is to provide the correct shaping, support and protection of a belt conveyor, reduce motion resistance as well as support for transported materials. The durability of idlers depends on numerous construction, engineering and operational factors. In practice, the idler bearings are often damaged due to wear and tear, jamming or seizure and the calculated durability does not comply with the actual lifetime of a bearing (Antoniak 2007). According to laboratory and operational practices, the quality of currently manufactured standard idlers is low and their average durability is approximately one year (Gładysiewicz, Orzeł, Noga 2012). Idlers do not meet the requirements specified in the PN-M-46606:2010 standard, even at the stage of their production, which is confirmed by tests carried out in the Department of Mechanical Devices Testing – the Central Mining Institute (GIG). Taking the above into consideration, testing stands which allow the testing of static and dynamic resistance of idlers’ movements as well as stands for examing the idlers’ water-tightness and dust-tightness in accordance with the PN-M-46606:2010 standard have been designed and constructed in the Department of Mechanical Devices Testing – the Central Mining Institute. The abovementioned testing stands were extended with additional functions, with regard to the above specified standard, facilitating the measurement of the temperature of bearing assemblies and to test the influence of rotational speed and idler loading in regards to durability. The tests were carried out on idlers with diameters of f133 and f159 mm, with a bearing assembly equipped with a single-raw ballbearing. A newly developed type of hybrid seal (labyrinth-lip), registered in the Patent Office of the Republic of Poland under the number W.121582 on 17 December 2012 (Pytlik, Rabsztyn 2012), was used in the idler with the diameter of f133. A typical labyrinth seal was used in the idler with the diameter of f159. On the basis of the durability tests carried out on both of these idlers it can be concluded that the applied research methodology describes the test conditions of idlers, in a manner as close as possible to their actual operational conditions, which were subject to a variety of factors for a total time of 116 hours, they included: dust, water, loads and variable rotational speed. This methodology allowed us to determine, even at the stage of laboratory tests, the suitability of a particular idler to certain operational conditions.

6

Stanowisko badawcze do szlifowania powierzchni walcowych zewnętrznych, konwencjonalnie i innowacyjnie

Wójcik R.

Mechanik

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2012

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R. 85, nr 8-9CD (NSOŚ)

305--310

7

Analiza systemów wykorzystywanych w badaniach uderzeniowego zużycia erozyjnego

Zbrowski A., Mizak W.

Problemy Eksploatacji

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2011

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nr 3

235-250

PL

W artykule zaprezentowano przegląd metod i systemów stosowanych w badaniach zużycia erozyjnego wywoływanego uderzeniowym oddziaływaniem cząstek erodenta na powierzchnię. W analizie uwzględniono rozwiązania bazujące na wytycznych normatywnych oraz oryginalne rozwiązania nieobjęte normami. Przedstawiono metody badań oraz wybrane przykłady rozwiązań praktycznych aparatury badawczej.

EN

The article presents the review of the methods and systems used for research on the erosion wear caused by the impact effect of the erosive particles on the surface. The analysis considers the solutions based on the standard definitions and original solutions not included in the standards. The research methods were presented as well as selected examples of practical solutions of research apparatus.

8

Zintegrowany modułowy symulator do badań tribologicznych endoprotez stawu biodrowego

Wieczorek A.

Obróbka Plastyczna Metali

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2007

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T. 18, nr 3

39-43

PL

W oparciu o wcześniejsze prace dotyczące konstrukcji symulatorów [1,2,3,4] zaprezentowano nowej generacji stanowisko do badań własności użytkowych endoprotez stawu biodrowego człowieka. Przedstawiony symulator umożliwia prowadzenie badań z bezstopniową regulacją obciążenia i dowolnym jego przebiegiem w czasie. W celu przyspieszenia badań zastosowano system trójmodułowy. Każdy moduł składa się z pary kinematycznej modelującej pracę stawu biodrowego. Moduły podłączone są do napędu równolegle. Dzięki temu możliwe jest określenie wartości rozrzutu parametrów zużycia już we wstępnym etapie badań. W pracy podano opis symulatora, schemat napędu elektrohydraulicznego oraz system sterowania.

EN

On the basis of the previous works concerning the construction of simulators [1,2,3,4], a new-generation stand for the testing of the service properties of human hip joint endoprostheses is presented. The presented simulator enables tests to be carried out with the infinitely variable adjustment of load and its arbitrary variation in time. To accelerate the tests, a three-module system was applied. Each module is composed of a kinematic pair that models the operation of the hip joint. The modules are connected to the drive in parallel. Owing to this, it is possible to determine the values of wear parameter scatter already at the preliminary stage of testing. The paper provides a description of the simulator, a schematic diagram of the electro-hydraulic drive and the control system.