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1
Content available Od Katedry Maszyn Górniczych do Katedry Inżynierii Maszyn i Transportu - 100 lat historii
Kotwica Krzysztof
Napędy i Sterowanie
|
2023
|
R. 25, nr 6
64--67
PL
W tym roku mija 100 lat od momentu powstania Katedry Maszyn Górniczych, której sukcesorem jest obecnie Katedra Inżynierii Maszyn i Transportu. W tym czasie Katedra kształcąc kadry inżynierskie wielokrotnie przyczyniła się swoimi działaniami do rozwiązywania trudnych problemów technicznych i rozwoju przemysłu wydobywczego oraz innych jego gałęzi w Polsce jak również na świecie, wpisując się w strategię powołanej przez marszałka Piłsudskiego Akademii Górniczo-Hutniczej. Ten piękny jubileusz stwarza okazję do podsumowania osiągnięć Katedry w działaniach na rzecz polskiego przemysłu, jak również nakreślenia perspektyw do dalszego rozwoju i aktywizacji młodych naukowców do współpracy z przemysłem.
2
Content available Technology of obtaining mixed alternative fuel based on organic substances for mining technological transport engines
Melnyk Vasyl, Romanyshyn Liubomyr, Mosora Yurii, Kotwica Krzysztof
Management Systems in Production Engineering
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2023
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nr 1 (31)
71--77
EN
In connection with the increase in the price of fuel based on hydrocarbons, the search and use of alternative types of fuel for machines in the mining and oil production industry is quite relevant today. Most of the existing alternative fuels by themselves cannot be considered as ready-to-use motor fuels. One of the ways to solve this problem is to use their mixtures with commercial fuels in certain ratios. This work deals with the development and research of the main characteristics of the mixer for obtaining mixed fuels based on diesel fuel and soybean oil, as well as the results of the study of the physical and operational properties of the obtained mixtures of different volume ratios of diesel fuel and soybean oil. The process of obtaining a mixed alternative fuel based on diesel fuel and soybean oil was implemented on a developed installation consisting of a mixer, the design of which is protected by a patent of Ukraine, and a gear pump. The study of the characteristics of the mixer as part of the installation showed that at a temperature of the components of the alternative fuel of 20°С, with a loss of full pressure on the mixer Δр ≈ (60-65) kPa, the volume consumption of soybean oil reached 10.7.10-6 m3/s. The time of preparation of the fuel mixture in the amount of 195 liters with a content of soybean oil of 10% ranged from 30 to 33 minutes. As research has shown, mixing soybean oil with diesel fuel in the amount of 5-50% vol. provides an improvement in viscosity-temperature properties and makes it possible to use such mixtures in diesel engines without changes in the design of the power supply system and regulation of fuel equipment, which characterizes soybean oil as a promising additive to diesel fuels to improve their technical and operational performance.
3
Content available remote New trends for mechanization, automation and robotics in mining
Krauze Krzysztof, Kotwica Krzysztof, Nawrocki Marcin
Napędy i Sterowanie
|
2022
|
R. 24, nr 7/8
64--69
EN
Mining, as one of mankind’s oldest undertakings and the first organized industry at all, is a very well established market with many opportunities for new technologies first of all mechanization and automation. Raw materials are elemental for almost every modern industry and technological developments and new processes have over the decades enabled broad availability of raw materials at acceptable prices. At the same time, due to novel processes and mechanization, the safety of the personnel working in the mining sectors has increased greatly and higher levels of sustainability and environmental friendliness were achieved. Mining, unlike other industries, is however dependent on finite resources. Consequently, the basic conditions for mining are constantly becoming more difficult. Many untouched deposits are located in greater depths, which means they can only be mined economically with higher raw material prices or when higher productivity levels are achieved. Moreover, aging workforce and skill shortage requires optimal usage of resources.
4
Regeneracja zębów zrywaków wibracyjnych na podstawie wyników symulacji procesów napawania łukowego
Rutkowski Sławomir, Kotwica Krzysztof, Danielewski Hubert
Transport Przemysłowy i Maszyny Robocze
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2020
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Nr 1
42--47
PL
Zrywaki wibracyjne stosowane są do urabiania mechanicznego skał zwięzłych, średnio zwięzłych i luźnych. Stanowią alternatywę dla wydobycia surowców skalnych metodą z użyciem materiałów wybuchowych, a także skutecznie ją uzupełniają przy rozdrabnianiu brył ponadgabarytowych. Elementami roboczymi zrywaków są zęby, które ulegają szybkiemu zużyciu. Autorzy proponują sposób regeneracji zębów przy zastosowaniu technik spawalniczych w oparciu o wykonane symulacje procesów napawania łukowego z wykorzystaniem programu Simufact Welding. Przeprowadzone procesy regeneracji pozwoliły nie tylko na przywrócenie parametrów początkowych zębów, ale także na zwiększenie ich trwałości względem elementów fabrycznie nowych.
EN
Vibrating ripper are components used mechanical mining of compact, medium and loose rocks. Rock mining technology using rippers are an alternative to explosive methods, moreover is a complement for explosive method to crushing oversized lumps. Working elements of ripper are teeth, which are liable to quick wear. The authors propose a tooth regeneration method using welding techniques aided by numerical simulations of arc welding processes performed in Simufact Welding software environment. Regeneration processes can be used not only for achieve primary properties of brand-new element but also to increase material durability over new elements.
5
Content available The Cutting Resistance of Rock Salt in Function of Temperature
Kotwica Krzysztof, Stopka Grzegorz
New Trends in Production Engineering
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2020
|
Vol. 3, Iss. 1
211--220
EN
Currently over then 16 percent of the total worldwide salt production is excavated in underground mines. Salt deposits often lie at great depths up to 1000 m, where the temperature of the surrounding rocks reaches 50°C and even exceeds it. A large part of it is exploited using mechanical methods, mainly with the use of road headers and continuous miners. When excavating salt rock, the cutters of the road header mining head come into contact with the rock. This generate friction and in consequence a rise in temperature. In AGH University of Science and Technology the laboratory tests were carried out to determine the effect of temperature on cutting resistance and selected mechanical properties of rock salt. On the special laboratory test stand the rock salt sample was cutted at three different temperatures - 20, 50 and 80°C. The cuttability index and the side chipping angle were measured for each temperature. Additionally the same tests were performed in the case of salt sample after cooling to room temperature. The selected mechanical parameters of rock salt - compressive, tensile and shear strength were also measured for the same temperature values. The obtained results were compared and described in the paper.
6
Content available Trenchless execution of microtunnels for municipal infrastructure in urbanized site – conception of a new solution
Kotwica Krzysztof, Suffner Hubert, Andras Andrei
Management Systems in Production Engineering
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2020
|
nr 4 (28)
276--282
EN
The technologies for trenchless execution of mini and microtunnels for an installation of municipal infrastructure in urbanized sites, used at present, are described in the article. The emphasis is laid on uncontrolled methods, in the case of the diameters of installations which do not exceed 200-250 mm and their length not bigger than 30- 40 m. Some issues connected with making the installations of this type, using conventional methods, are also presented. A conception of equipment (ground rocket) for an trenchless execution of short-distance microtunnels of the diameter up to 200 mm and the length up to 30 m with an innovative electric drive, developed at the Department of Machinery Engineering and Transport of the AGH in Cracow as an alternative for the solutions applied nowadays, is described. An electric linear motor, whose conception is presented in the article, was installed in the head of the device. The goal of these works was possibility of using new solution of ground rocket without additional equipments for pneumatic supply with compressed air. New concept of proposed ground rocket can be used with feeding directly from the domestic electric network. The device is intended for execution of installation in incoherent and low-compact ground.
7
Sposoby zabezpieczania powierzchni roboczych wykładzin i płyt pancernych w kruszarkach młotkowych dla surowców skalnych
Rutkowski Sławomir, Kotwica Krzysztof, Górski Marcin
Transport Przemysłowy i Maszyny Robocze
|
2019
|
Nr 4
30--34
PL
Przeróbka mechaniczna surowców skalnych to główna operacja w procesie ich przetwarzania, w celu pozyskania kruszyw. Kruszywa są podstawowym materiałem stosowanym w budownictwie i drogownictwie, a ich rosnący zbyt wymusza na producentach systematyczne zwiększanie wydajności. W tym celu niezbędne staje się stosowanie nowych rozwiązań technicznych, pozwalających na mniej awaryjną pracę urządzeń stosowanych do przerobu kruszyw. Podstawowe urządzenia, stosowane w zakładach mechanicznego przerobu kruszyw, to kruszarki szczękowe, stożkowe, walcowe i udarowe młotkowe. Przebieg procesu kruszenia zależy głównie od właściwości surowca oraz od konstrukcji maszyny i jej sposobu działania oraz stosowanych elementów roboczych, tj. płyt kruszących, stożków, młotków, bijaków, płyt pancernych oraz wykładzin. Autorzy skupili się na sposobach zabezpieczania w przedsiębiorstwie PW TSA w Stalowej Woli powierzchni roboczych płyt pancernych i wykładzin w kruszarkach młotkowych metodą napawania materiałami CAPILLA. Przeprowadzono badania laboratoryjne i przemysłowe wytypowanych elementów w celu potwierdzenia skuteczności proponowanych rozwiązań.
EN
Mechanical processing of rock raw materials is a main stage of processing them in order to win aggregates. Aggregates are basic materials using in building and road industry, their growing demand force on the manufactures systematic increasing of efficiency. For this purpose, it becomes necessary to use new technical solutions which allow less emergency operation of equipment used for processing aggregates. Basic devices using in aggregates processing plants are jaw, tapered, cylindrical, impact and hammer crushers. Crushing process depends on raw materials property, machine construction and its way of working and working parts: crushing plates, cones, hammers, wises, armour plates and linos. Authors were focused on methods of protecting in an enterprise PW TSA located in Stalowa Wola on surfaces of working elements and linos in hammer crushers by using welding Capilla goods and technologies. There were conducted laboratory and industrial tests of selected elements carried out to confirm the effectiveness of the proposed solutions.
8
Content available Narzędzia dyskowe - alternatywa dla narzędzi skrawających
Kotwica Krzysztof
Systemy Wspomagania w Inżynierii Produkcji
|
2019
|
Vol. 8, iss. 1
103--114
PL
W artykule przedstawiono problemy związane z urabianiem zwięzłych i bardzo zwięzłych skał narzędziami skrawającymi, głównie nożami styczno-obrotowymi. Opisano obecnie wykorzystywane narzędzia dyskowe, ich parametry oraz sposób pracy. Przedstawiono wady wybranych rozwiązań i związane z tym przeszkody w ich szerszym zastosowaniu w górnictwie. Zaprezentowano kierunki dalszego rozwoju narzędzi dyskowych pozwalające na ich wykorzystanie przykładowo w kombajnach ścianowych oraz kombajnach chodnikowych ramionowych.
EN
The article presents problems related to the mining of compact and very hard rocks with cutting tools, mainly with tangential-rotary picks. The currently used disc tools, their parameters and the way of working are described. The disadvantages of selected solutions and related obstacles to their wider use in mining have been presented. The directions of further development of disk tools were presented, allowing their use, for example, in mining heads of longwall shearers and roadheaders.
9
Content available Vibration analysis of a bucket wheel excavator boom using rayleigh’s damping model
Popescu Florin Dumitru, Radu Sorin Mihai, Kotwica Krzysztof, Andraș Andrei, Kertesz (Brînaș) Ildiko, Dinescu Stela
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
233--241
EN
For the ERc 1400-30/7 type bucket wheel excavator (BWE) used in various Romanian open pit mines, a virtual model of the boom was constructed in SolidWorks. On this model, the variable in time forces acting during the excavation process were simulated, and the time history analysis (time response) was performed. This dynamic time response analysis was performed for excavation of homogenous material only, considering the damping as being of Rayleigh’s type, where the damping matrix is a linear combination of the mass and stiffness matrices. Based on the conducted analysis, the displacements of the boom during excavation were observed.
10
Content available The effect of temperature on the mechanical properties and workability of rock salt
Małkowski Piotr, Bednarek Łukasz, Kotwica Krzysztof, Stopka Grzegorz
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
384--393
EN
Underground salt mining accounts for about 16 percent of the total salt production worldwide. When excavating salt rock, the cutters of the road header come into contact with the rock. This produces friction and, consequently, a rise in temperature. Generally, as temperature increases, salt gradually loses its plasticity. The extent of these alterations depends on the presence of other minerals in the rock. This paper presents the results of laboratory tests on regularly shaped samples of salt. An analysis was performed of the results of compressive, tensile and induced-shear strength, and of Young's modulus, Poisson's ratio, cuttability index and side chipping angle. The testing was conducted on samples with a temperature of about 20°C and samples heated to 50°C and 80°C. The tests showed that as temperature increased, so did compressive and tensile strength, and longitudinal and transverse strain of salt. The temperature increase caused, however, a decrease in shear strength. The cuttability index and the side chipping angle also decreased when the heated samples were being cut. The percentage changes in the parameters within the 60-degree temperature range were as high as several dozen percent.
11
Content available Drive simulation tests for electric drilling rig
Kotwica Krzysztof, Stopka Grzegorz
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
96--103
EN
The article presents methodology and selected results of simulation tests of diesel and electric dive system for drilling rig. Research in this field were conducted under the project no. POIR.01.01.01-00-D011/16 entitled „New generation of modular rigs, drilling and bolting, with battery drives, designated to work in underground cooper ore and raw rock material mines”. The project is funded by the National Center of Research and Development (NCBiR). The aim of the project is to design and implementation of innovation drilling and bolting rig with electric drive system. Due to the complexity of the structure of the drive system (mechanical, hydraulic and electrical elements), it was necessary to use advanced simulation software dedicated to multiphysics analysis. Data presented in the article can be used as guidelines in design process of drilling and bolting rigs as well as in optimization their driving system and mechanical construction.
12
Content available Asymmetrical mini disk tools - possibilities of use and directions for further development
Kotwica Krzysztof
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
223--232
EN
The paper presents a new solution of asymmetrical mini disk tools for mining head of roadheader designed for hard and very hard rock mining. In the first part the benefits of disk tools used in TBM's and special tunneling machines were presented. Next part presents the results of works and laboratory tests performed for developing of new solution of asymmetrical mini disk tools. On the basis of these results new mining head equipped with mini disk tools with a complex trajectory was designed. The results of field tests with different constructional and material solutions of asymmetrical mini disk tools were presented. The directions for further development were described.
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