Wyniki wyszukiwania - BazTech

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A method of evaluating energy consumption of the cutting process based on the example of hard cheese

Kowalik K., Sykut B., Marczak H., Opielak M.

Eksploatacja i Niezawodność

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2013

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Vol. 15, no. 3

241-245

EN

The article demonstrates a method of measuring energy requirements of a cutting process as researched at the Department of Process Engineering, Safety and Ecotechnology. The specially constructed workstation and examples of results obtained are presented. The cutting process has been conducted using stainless steel and low-friction coated blades with each blade's entry conditions variables, such as speed and the angle of entry, determined. In order to compare cutting resistance caused by friction between the blades' surface and the cut substance, wire cutting has also been performed.

PL

W artykule przedstawiono metodę badania energochłonności procesu cięcia opracowaną w Zakładzie Inżynierii Procesowej, Bezpieczeństwa i Ekologii. Zaprezentowano skonstruowane stanowisko badawcze oraz przykładowe wyniki badań wykonane z wykorzystaniem tego stanowiska. Proces cięcia prowadzono nożami ze stali narzędziowej oraz pokrytymi powłokami charakteryzującymi się małym współczynnikiem tarcia, przyjmując w planie badań dla każdego noża zmienne wejściowe: kąt ostrza oraz prędkość cięcia. Aby porównać opory cięcia wynikające z tarcia materiału o powierzchnię noża przeprowadzono także cięcie materiału drutem.

2

Effect of Exit Blade Angle, Viscosity and Roughness in Centrifugal Pumps Investigated by CFD Computation

Li W.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2011

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Vol. 15, No 1

21-41

EN

It has long been known that the exit blade angle plays a very important role in the performance of a centrifugal pump handling water or viscous oil. The effect of exit blade angle on the performance and flow of centrifugal pumps is usually investigated experimentally. However, due to the high cost and limited data that can be obtained by experiment, currently there is a great need for this effect to be studied numerically by means of computational fluid dynamics (CFD). At present, extensive comparisons between experiment and simulation regarding the performance of viscous oil and flow in centrifugal pumps with different exit blade angles are not available. Hydraulic performance and flow details in the impeller and the volute of a centrifugal pump with an exit blade angle of 44o were investigated numerically with the CFD code Fluent, using water and viscous oil as the working fluid, respectively. The effect of exit blade angle was then elucidated by comparing the performance and flow with that of a pump with an exit blade angle of 20o. It was determined that the results for the performance and flow obtained by means of CFD were in qualitative agreement with the observations. The sudden-rising-head effect is dependent on roughness and viscosity. The unstable zone in the theoretical head curve of the impeller at a low flow rate was attributed to the strong reaction of the volute to the flow in the vicinity of the impeller exit. The flow in the impeller with a large exit blade angle was subject to separation near the blade pressure side, however, a large exit blade angle helped improve the pump performance of viscous oil.

3

Wpływ kąta zaostrzenia noża na przebieg cięcia wybranych warzyw korzeniowych

Nadulski R., Skwarcz J., Strzałkowska K.

Inżynieria Rolnicza

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2010

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R. 14, nr 7

161-166

PL

W pracy przedstawiono metodykę pomiaru oraz wyniki badań, przeprowadzonych w warunkach laboratoryjnych, cięcia prostopadłościennych próbek korzeni marchwi i selera. Stwierdzono statystycznie istotny wpływ kąta zaostrzenia noża na wartość sił cięcia i pracy cięcia. Spośród badanych korzeni wyższe wartości maksymalnej siły cięcia i pracy cięcia otrzymano dla korzeni selera. W warunkach eksperymentu nie stwierdzono wpływu prędkości zespołu tnącego na wartości siły i pracy cięcia.

EN

The work presents the methodology of measuring and results of test conducted in laboratory environment, regarding cutting cuboidal samples of carrot and celery roots. It was proved that the knife sharpening angle has a statistically crucial impact on the values of cutting force and cutting work. From among the tested roots, higher maximum values of cutting force and cutting work were recorded for the celery roots. It was found that in the experimental environment there is no impact of the cutting unit speed on the values of cutting force and work.