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Tytuł:
Effects of propeller fouling on the hydrodynamic performance of a marine propeller
Autorzy:
Zinati, Ali
Ketabdari, Mohammad Javad
Zeraatgar, Hamid
Powiązania:
https://bibliotekanauki.pl/articles/34602878.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propeller performances
blade roughness
frictional resistance
CFD simulation
fouling
Opis:
Propeller performance is typically considered under clean conditions, despite the fact that fouling is an inevitable phenomenon for propellers. The main objective of this study is to investigate the effects of roughness due to fouling on the performance of a propeller using a CFD simulation in conjunction with the roughness function model. A simulation of a clean propeller is verified for a five-blade propeller model using existing experimental results. A roughness function model is then suggested based on existing measured roughness data. The simulations are extended for the same propeller under varying severities of roughness. Initially, it is concluded that KT and ηo gradually decrease with increasing fouling roughness, while KQ increases, compared to smooth propeller. For instance, at J=1.2 for medium calcareous fouling, KT is reduced by about 26%, KQ increases by about 7.0%, and ηo decreases by 30.9%. In addition, for the rough propeller, the extra power required is defined as the specific sea margin (SSM) to compensate for the power loss. A slight roughness causes a large decrease in ηo. A propeller painted with foul-release paint and an unpainted propeller are found to require 2.7% SSM and 57.8% SSM over four years of service, respectively. Finally, the use of foul-release paints for propeller painting is strongly advised.
Źródło:
Polish Maritime Research; 2023, 4; 61-73
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of Fouling from Steel Plate Surfaces Based on Multi-Frequency Eco-Friendly Ultrasonic Guided Wave Technology
Autorzy:
Huang, Mingkun
Jin, Shuo
Nie, Gaoqian
Wang, Xiaopeng
Zhang, Quanpeng
An, Yang
Qu, Zhigang
Yin, Wuliang
Powiązania:
https://bibliotekanauki.pl/articles/31339786.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
fouling removal
cavitation
eco-friendly
ultrasonic guided waves
multi-frequency
Opis:
Fouling is inevitable on the surfaces of industrial equipment, especially on heat-exchanging surfaces in contact with fluids, which causes water pollution and destroys the ecological environment. In this paper, a novel fouling-removal methodology for plate structure based on cavitation by multi-frequency ultrasonic guided waves is proposed, which can remove fouling on stainless steel plates. A numerical simulation method has been developed to study the acoustic pressure distribution on a steel plate. According to the simulation results, the distribution of sound pressure on the plate under triple-frequency excitation is denser and more prone to cavitation than in single-frequency cases and dual-frequency cases, which improves fouling removal rate. The stainless steel plate is immersed in water for the descaling experiment, and the results show that the fouling removal rates of three water-loaded stainless steel plates under different single-frequency excitation seem unsatisfactory. However, the multi-frequency excitation improves the descaling performance and the removal rate of fouling reaches 80%. This new method can be applied to the surface descaling of large equipment plates, which is of great significance for purifying water quality and protecting the ecological environment.
Źródło:
Archives of Acoustics; 2023, 48, 4; 593-601
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dependence between nominal power deterioration and thermal efficiency of gas turbines due to fouling
Autorzy:
Herdzik, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/24202511.pdf
Data publikacji:
2022
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
gas turbine
gas turbine deterioration
reasons of fouling
thermal efficiency
performance
fuel consumption
Opis:
Deterioration in the performance of gas turbines is a well-known phenomenon occurring during their operation. The most important form is a decrease in the internal efficiency of the compressor and turbine due to fouling, which is the most significant deterioration problem for an operator. This article presents the effect of gas turbine fouling as a drop in airflow, pressure ratio, and compressor efficiency resulting in a reduction in power output and thermal efficiency. This resulted in a decrease in the nominal power of a gas turbine and an increase in the fuel consumption (heat rate). The fouling effects were described using the example of the MT30 marine gas turbine with a nominal power of 36 MW. The estimated profit loss during the operation of the gas turbine was within the range of 1–10% of the total fuel consumption cost. A 2% deterioration in the output of a gas turbine accounted for US$ 10,000–20,000 per year and 1 MW of gas turbine nominal power (according to marine fuel prices in 2019–2020) – this means at least US$ 300,000 annually for an MT30. Due to the low accuracy of fuel consumption measurements, another possibility was provided. The correlation between the gas turbine power deterioration and thermal efficiency was presented, which made it possible to estimate the increase in the specific and total fuel consumption when the nominal power deterioration is known. Two linear approximations were proposed to calculate increases in the annual operating costs for an MT30 due to fouling.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2022, 69 (141); 45--53
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
WWTP effluent treatment with ultrafiltration with different mixed matrix nanocomposite membranes : comparison of performance and fouling behavior
Porównanie efektywności i foulingu ultrafiltracyjnych membran nanokompozytowych : zmieszana matryca podczas ultrafi ltracji odpływów z oczyszczalni ścieków
Autorzy:
Kamińska, Gabriela
Powiązania:
https://bibliotekanauki.pl/articles/2203135.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrafiltration
fouling
micropollutants
nanocomposite membranes
WWTP effuent
ultrafiltracja
mikrozanieczyszczenia
membrany nanokompozytowe
oczyszczalnie ścieków
Opis:
Polymer mixed-matrix nanocomposite membranes were prepared by a wet-phase inversion method and used in ultrafiltration processes to treat wastewater treatment plant effluent spiked with organic micropollutants. The effects of halloysite (Hal), TiO2, and functionalized single-walled carbon nanotube (SWCNT-COOH) nanofillers on the treatment efficiency, permeability loss, and fouling behavior of polyethersulfone (PES) membranes were investigated and compared with those of a pristine PES membrane. The nanocomposite membranes exhibited lower porosity and stronger negative surface charge because of the added hydrophilic nanofillers. The PES-Hal membrane achieved the optimal balance of permeability and micropollutant removal owing to enhanced pollutant adsorption on the membrane surface and the creation of an easily removable cake layer (i.e., reversible fouling). The PES-SWCNT-COOH membrane demonstrated the highest treatment efficiency, but also the high permeability loss. In contrast, PES-TiO2 exhibited excellent antifouling properties, but poorer treatment capabilities.
Celem pracy było porównanie zdolności separacyjnych i tendencji do foulingu trzech membran nanokompozytowych podczas oczyszczania odpływu z oczyszczalni, który domieszkowano mikrozanieczyszczeniami organicznymi. Membrany nanokompozytowe typu mieszana matryca preparowano metodą inwersji. Membrany nankomopomozytywe domieszkowano haloizytem, nanotlenkiem ditytanu lub jednościennymi nanorurkami węglowymi funkcjonalizowanymi grupami karboksylowymi (SWCNT-COOH). Membrany nanokompozytowe charakteryzowały się niższą porowatością i silniejszym ujemnym ładunkiem powierzchniowym dzięki dodaniu hydrofilowych nanowypełniaczy. Membrana PES-Hal została uznana za najbardziej korzystną pod względem wydajności hydraulicznej i współczynników retencji mikrozanieczyszczeń. Było to wynikiem zwiększonej adsorpcji zanieczyszczeń na powierzchni membrany i tworzeniu łatwo usuwalnej warstwy placka (tj. oporu wywołanego foulingiem odwracalnym). Membrana PES-SWCNT-COOH charakteryzowała najwyższymi współczynnikami retencji, ale również dużą utratą przepuszczalności. Natomiast PES-TiO2 wykazywała doskonałe właściwości przeciwporostowe, ale słabsze właściwości separacyjne względem badanych mikrozanieczyszczeń.
Źródło:
Archives of Environmental Protection; 2022, 48, 4; 35--44
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An influence of fouling gathered on the heat transfer surfaces on the heat performance characteristics of the ship steam systems heat exchangers
Autorzy:
Hajduk, T.
Powiązania:
https://bibliotekanauki.pl/articles/1841551.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
marine power plant
gathering of fouling
heat transfer surface
heat performance characteristics
thermal resistance
heat trransfer
heat exchangers
Opis:
More than half of the incidents reported to EMSA relate to nautical events such as collision, groundings and contacts. Knowledge of accurate and high-integrity positioning is therefore not only a need for future automated shipping but a base for today’s safe navigation. Examples on accidents include Ever Given in the Suez Canal and HNoMS Helge Ingstad in Norway. A Network-RTK (NRTK) service can be used as an augmentation technique to improve performance of shipborne GNSS receivers for future positioning of manned and unmanned vessels in restricted areas, such as port areas, fairways, and inland water ways. NRTK service providers generate RTK corrections based on the observations of networks of GNSS reference stations which enables the users to determine their position with centimeter accuracy in real-time using a shipborne GNSS receiver. Selection of appropriate communication channels for dissemination of NRTK corrections data is the key to a secure positioning (localization) service. In PrePare-Ships project, the modern maritime communication system VDES (VHF Data Exchange System) is proposed to distribute SWEPOS (NRTK in Sweden) correction data to shipborne positioning modules. VDES is a very reliable technique and it is compatible with most onboard functionalities. In order to minimize the impact on the overall VDES data capacity in a local area, NRTK correction data shall only occupy a single VDES slot with a net capacity of 650 bytes. Update rates may vary but are preferably at 1Hz. However, NRTK correction data size changes instantly, depending on the number of visible GNSS satellites, and the data rate can therefore sometimes reach in excess of 1000 byte/s. In this study, a smart technique is proposed to reduce size of NRTK correction data to instantly adapt with the VDES requirements by choosing a combination of specific signals, satellites or even constellations such that the data rate is not more than 650 byte/s, and at the same time it achieves optimal positioning performance with the accuracy required by the PrePare-Ships project application.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2021, 15, 1; 183-189
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of the solid fouling effect on the air-cooled apparatus characteristics
Autorzy:
Morozyuk, Larisa
Sokolovska-Yefymenko, Viktoriia
Moshkatiuk, Andrii
Hrudka, Bohdan
Powiązania:
https://bibliotekanauki.pl/articles/2014236.pdf
Data publikacji:
2021
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
air condenser
fouling
experimental bench
heat exchange surface
chłodnica powietrza
zanieczyszczenie
stanowisko doświadczalne
powierzchnia wymiany ciepła
Opis:
External fouling on the heat exchange surface of air-cooled apparatus are formed during operation, which leads to a significant increase in energy consumption and deviations from the optimal operating mode of the entire system. This phenomenon is a problem for all energy conversion systems. This paper presents the experimental study results of a complex of a commercial cooled object with real fouling on the air condenser surface. To study the effect of fouling, an experimental bench was developed – a single-stage refrigerating machine that provides cold supply to a thermostatic chamber. Three types of fouling were used: sand, fluff and dust. Fouling were picked from the operating condensers and identical in the type of heat exchange surface to the experimental sample. With a change in the quantitative and qualitative composition of the fouling, the air condenser thermal and aerodynamic characteristics and the energy efficiency of the machine as a whole were determined. The experiment showed that at maximum fouling of the heat exchange surface with sand and fluff, air movement stops. This means that at a certain thickness of sand and fluff layer, an air impermeable dense structure is formed. Dust with the same form of filling the free space for the flow remains permeable to air. Experiments showed that the qualitative composition of the fouling is the main factor that determines the heat exchanger performance. It was found that from the experimental set of fouling, roadside dust has the greatest negative effect on the condenser characteristics and the machine as a whole. The aerodynamic properties of the heat exchanger depend to some extent on the qualitative composition of the fouling. As a conclusion, it was suggested that the process nature of air flow passing through the investigated fouling can be described as gas flows in porous media.
Źródło:
Science, Technology and Innovation; 2021, 12, 1; 1-9
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An assessment of the susceptibility of bacterial cellulose films to fouling by mold fungi
Autorzy:
Betlej, Izabela
Krajewski, Krzysztof
Borysiuk, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2200174.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
bacterial cellulose
degree of fouling
kombucha
mold fungi
Opis:
An assessment of susceptibility of bacterial cellulose films to fouling by mold fungi. The article presents the results of research on the degree of fouling of films made of bacterial cellulose by selected mold fungi. The degree of fouling of the cellulose film was compared with the degree of fouling of pine wood samples. On the basis of the obtained results, it was found that the cellulose film is covered by mold fungi. At the same time, it was found that T. viride grows on wood much faster than bacterial cellulose.
W artykule przedstawiono wyniki badań stopnia porastania folii wytworzonych z celulozy bakteryjnej przez wybrane grzyby pleśniowe. Stopień porastania folii celulozowej porównano ze stopniem porastania próbek drewna sosny. Na podstawie uzyskanych wyników stwierdzono, że folia celulozowa ulega porastaniu przez grzyby pleśniowe. Jednocześnie ustalono, że grzyb T. viride znacznie szybciej porasta drewno niż celulozę bakteryjną.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2020, 110; 103--109
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of antifouling paints and nautical tourism on the sustainability of marine environment in the case of the village ports of a small Island
Autorzy:
Ivče, R.
Paparić, D.
Zekić, A.
Škapul, M.
Powiązania:
https://bibliotekanauki.pl/articles/1841584.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Marine Environment
antifouling paints
nautical tourism
small island
village ports
underwater hull fouling
underwater hull maintenance
pleasure boats
Opis:
The problem of underwater hull fouling has been mostly noticed by the pleasure boat owners when reducing the boat speed. In order to decrease the fouling of the underwater part of the hull, antifouling paints have been used. Some kinds of antifouling paints have become a serious environmental problem due to its very harmful effect on marine organisms and also, indirectly, on humans. Scientific research conducted in this domain has confirmed contamination by toxic compounds as a result of the usage of antifouling paints over long period of time. The paper is focused on underwater hull maintenance, especially when applying antifouling systems on pleasure crafts owned by tourists and local residents, in the example of the village ports of a small island. A survey was conducted among the residents who use ports to determine their knowledge regarding the harmful effects of biocidal coatings and the possible harmless maintenance of the underwater hull part. This paper aims to indicate the necessary equipment and procedures in the two small local ports in order to maintain pleasure boats in environmentally acceptable manner.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 3; 701-707
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of the type of biomass and ashing temperature on the properties of solid fuel ashes
Autorzy:
Horák, Jiří
Kuboňová, Lenka
Dej, Milan
Laciok, Vendula
Tomšejová, Šárka
Hopan, František
Krpec, Kamil
Koloničný, Jan
Powiązania:
https://bibliotekanauki.pl/articles/779459.pdf
Data publikacji:
2019
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
biomass
ashing temperature
ash fusion temperature
slagging index
fouling index
Opis:
Ashes were prepared by annealing selected types of solid fuels (biomass: corn cobs, sunflower husks, olive pomace, hay pellets and rice husks; coal: lignite and bituminous; and alternative fuel: paper sludge) at different temperatures (550°C, 815°C and 975°C). Based on X-ray fluorescence spectra, the slagging/fouling indexes were used to study the effects of the type of ash and the ashing temperature on the ash fouling and slagging properties. Slagging indexes were compared with the ash fusion temperatures. Ash fusion temperatures were measured by a LECO AF-700. The lowest deformation temperature (below 1000°C) was seen for the ashes prepared from hay pellets and corn cobs. On the other hand, the deformation temperature exceeded 1500°C for ashes prepared from paper sludge, sunflower husks and rice husks. By calculating the different slagging/fouling indexes, all the ashes exhibited slagging/fouling problems of varying degrees.
Źródło:
Polish Journal of Chemical Technology; 2019, 21, 2; 43-51
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Liquid Hydroxide Based Additives on Suppression of Slag Formation in Granulation Furnaces
Wpływ dodatków na bazie ciekłego wodorotlenku na tworzenie żużla w piecach granulacyjnych
Autorzy:
Nadkanska, Hana
Zavada, Jaroslav
Blazek, Vladislav
Mudrunka, Jaroslav
Powiązania:
https://bibliotekanauki.pl/articles/319304.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
żużel
obrastanie
piec do granulacji
temperatura topnienia popiołu
wydajność kotła
slag
slagging
fouling
granulation furnace
ash fusion temperature
boiler efficiency
Opis:
The article deals with the possibility of limiting slag formation in specific heating plant boilers by adding an additive to the batch. The possibilities of reducing slag formation in energy boilers have already been investigated in laboratory conditions where the addition of the NALCO 8270 additive has not led to demonstrable results [13]. X-ray diffraction and X-ray fluorescence of slag samples collected from granulation boilers were performed within the experiment. Furthermore, calculations of the efficiency of the boilers operated in the heat plant were performed using the indirect method. The efficiency was calculated for boilers without dosing and with additive dosing. The results show that using the additive increases the efficiency of the boiler by about 1%.
W artykule przedstawiono możliwość ograniczenia tworzenia się żużla podczas spalania w kotłach grzewczych poprzez dodatki do wsadu. Możliwości ograniczenia powstawania żużla w kotłach energetycznych zostały już zbadane w warunkach laboratoryjnych, w których dodanie dodatku NALCO 8270 nie doprowadziło do pozytywnych wyników [13]. W ramach eksperymentu przeprowadzono dyfrakcję rentgenowską i fluorescencję rentgenowską próbek żużla pobranych z kotłów. Ponadto obliczenia wydajności kotłów pracujących w ciepłowni przeprowadzono metodą pośrednią. Wydajność obliczono dla kotłów bez dozowania i z dozowaniem dodatków. Wyniki pokazują, że dodatek zwiększa wydajność kotła o około 1%.
Źródło:
Inżynieria Mineralna; 2019, 21, 1/2; 341-346
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparowanie, struktura i właściwości membran nanokompozytowych wytwarzanych metodą inwersji faz
Preparation, structure and properties of nanocomposite membranes prepared by phase inversion
Autorzy:
Adamczak, Michał
Kamińska, Gabriela
Bohdziewicz, Jolanta
Powiązania:
https://bibliotekanauki.pl/articles/945840.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
membrany nanokompozytowe
inwersja faz
nanocząstki
porowatość
hydrofobowość/hydrofilowość
fouling
nanocomposite membranes
phase inversion
nanoparticles
porosity
hydrophilicity/hydrophobicity
Opis:
Artykuł stanowi przegląd literatury dotyczącej wytwarzania, struktury i właściwości membran preparowanych z roztworów polimerowych modyfikowanych nanocząstkami. Dodatek nanomateriałów wpływa na budowę strukturalną i właściwości fizykochemiczne, a także właściwości transportowo-separacyjne wytworzonych membran. Przedstawiono stan najnowszej wiedzy na temat membran nanokompozytowych wytwarzanych za pomocą inwersji faz.
Preparation, structure and properties of nanocomposite membranes prepared by phase inversion The article is a review of the literature related to the techniques of preparation, structure and properties of the membranes obtained from polymer solutions modified with nanoparticles. The incorporation of nanomaterials influences the structure and physicochemical properties as well as transport and separation characteristics of the produced membranes. The current state-of-the-art in the field of polymer nanocomposite membranes prepared by phase inversion is presented.
Źródło:
Polimery; 2019, 64, 3; 173-180
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ceramic membrane fouling in ultrafiltration process of chicken egg white aqueous solution
Autorzy:
Borysiak, M.
Gabruś, E.
Powiązania:
https://bibliotekanauki.pl/articles/185007.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrafiltration
ceramic membrane
chicken egg white
fouling
membrane transport resistance
ultrafiltracja
membrana ceramiczna
Opis:
This paper presents an experimental study on chicken egg white solution ultrafiltration, where membrane fouling has been the main point of concern. Separation process has been performed with a 150 kDa tubular ceramic TiO2/Al2O3 membrane. The operating parameters have been set as follows: transmembrane pressure 105–310 kPa, cross-flow velocity 2.73–4.55 m/s, pH 5 and constant temperature of 293 K. Resistance-in-series model has been used to calculate total resistance and its components. The experimental data have been described with four pore blocking models (complete blocking, intermediate blocking, standard blocking and cake filtration). The results obtained show that the dominant fouling mechanism is represented by cake filtration model.
Źródło:
Chemical and Process Engineering; 2018, 39, 3; 295--308
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of scale deposition on maintenance of injection molds
Wpływ odkładania się kamienia na eksploatację form wtryskowych
Autorzy:
Poszwa, P.
Szostak, M.
Powiązania:
https://bibliotekanauki.pl/articles/1365593.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
injection mold
cooling phase
lime scale
fouling
forma wtryskowa
faza chłodzenia
kamień osadowy
zanieczyszczenia
Opis:
The cooling system of an injection mold serves a substantial role in the process of plastic injection. It is responsible for efficient dissipation of heat from the injection mold, generated by the plasticized material which during the injection phase is introduced into the mold. Apart from rapid heat dissipation, it is important to achieve uniform distribution of temperatures on the surface of the molding cavity. This study focuses on the phenomenon of lime scale deposition in injection mold cooling systems. Lime scale deposition results in reduction of the cooling canal’s section diameter, as well as a clear reduction in cooling efficiency due to its lowered thermal conductivity. The study specifies the influence of many factors (geometry of the cooling system and molded piece, coolant temperature, type of plastic material) on the utilization of the injection mold as a result of the occurrence of lime scale in the cooling system. The conducted numerical simulations have allowed to account for the impact of the deposit layer’s thickness on the distribution of temperatures on the molding cavity’s surface, the average injection mold temperature, as well as the time required to solidify the plastic material products.
Układ chłodzenia formy wtryskowej odgrywa niebagatelną rolę w procesie wtryskiwania tworzyw sztucznych. Odpowiada on za sprawny odbiór ciepła z formy wtryskowej dostarczonego przez uplastycznione tworzywo, które w fazie wtrysku jest wprowadzone do formy. Oprócz szybkiego odbioru ciepła istotne jest, aby rozkład temperatury na powierzchni gniazda formującego był równomierny. W niniejszej pracy skupiono się na zjawisku osadzania się kamienia w układach chłodzących form wtryskowych. Kamień powoduje zarówno zwężenie przekroju kanału chłodzącego, jak i wyraźny spadek wydajności chłodzenia ze względu na jego niską przewodność cieplną. W pracy określono wpływ wielu czynników (geometria układu chłodzenia oraz wypraski, temperatura cieczy chłodzącej, rodzaj tworzywa) na eksploatację formy wtryskowej w wyniku pojawienia się kamienia w układzie chłodzącym. Przeprowadzone symulacje numeryczne pozwoliły uwzględnić wpływ grubości warstwy osadu na rozkład temperatury na powierzchni gniazda formującego, średnią temperaturę formy wtryskowej, a także czas potrzebny do zestalenia wyrobów produkowanych z tworzyw sztucznych.
Źródło:
Eksploatacja i Niezawodność; 2018, 20, 1; 39-45
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Membrane fouling in the ultrafiltration of water–protein–sodium chloride model systems
Autorzy:
Ćwirko, K.
Tomczak, E.
Szaniawska, D.
Powiązania:
https://bibliotekanauki.pl/articles/185550.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrafiltration
ceramic membranes
fouling models
BSA
myoglobin
ultrafiltracja
mioglobina
Opis:
This paper presents ultrafiltration results of model BSA (bovine serum albumin) and MB (myoglobin) solutions prepared with or without NaCl addition. The protein concentrations in the solutions were equal to 0.05 g dm 3 for MB and 0.5 g dm 3 for BSA. The ultrafiltration tests were performed using a laboratory scale unit equipped with 90 mm ceramic disc membranes with a filtration area of 5:6-10-3 m2 and cut-off of 50 or 150 kDa. The tests were run under constant process conditions, i.e. a cross flow volume (CFV) of 5 ms-1, transmembrane pressure (TMP) of 0.2 MPa, temperature of 20 ◦C and NaCl concentration of 0 or 10 wt%. The installation worked in a semi-open mode with a continuous permeate discharge and retentate recycle. The performance of the membranes was measured with the permeate volumetric flow rate, JV (m3m 2s 1) while their selectivity was determined by the protein rejection, R. The paper evaluates and discusses the protein rejection mechanisms as well as the influence of the membrane cut-off and sodium chloride concentration in the feed on the flux decline during the ultrafiltration of BSA and MB. Moreover, it provides an analysis of the first fouling phase by applying usual filtration laws.
Źródło:
Chemical and Process Engineering; 2018, 39, 2; 185--196
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods for regeneration and storage of ceramic membranes
Autorzy:
Zielińska, A.
Powiązania:
https://bibliotekanauki.pl/articles/106051.pdf
Data publikacji:
2018
Wydawca:
Centrum Badań i Innowacji Pro-Akademia
Tematy:
ceramic membranes
fouling
membranes regeneration
membrana ceramiczna
regeneracja membran
Opis:
Ceramic membranes are among one of the most promising candidates for membrane applications, owing to their excellent resistance to mechanical, chemical, and thermal stresses. These advantages make them an attractive filter material. An additional benefit which is extremely important for the industry, is their possibility of continuous operation at high efficiency while maintaining constant transmembrane pressure. Due to the inorganic material from which they are made, ceramic membranes have the possibility of being cleaned by steam sterilization and are resistant to micro-organisms. Although, due to low production costs, ceramic membranes are one of the most cost-effective membrane filtration technologies they are prone to substantial fouling. When used, a layer of contaminants is formed on the active surface, often reducing or completely filling the membrane pores resulting in fouling and concentration polarization. These phenomena cause a decreased efficiency of the process, which leads to the need for the membrane to be replaced with a new one. However, ceramic membranes have the possibility of being regenerated through a series of activities and the use of various chemical agents. The use of regenerated membranes would provide the opportunity to reduce exploitation costs. Although membrane regeneration does not guarantee a return to the initial parameters, it does allow for the recovery of high permeation flow. The aim of the research was to compare operating parameters of the ceramic membranes after multiple use and longtime storage with different condition of storage.
Źródło:
Acta Innovations; 2018, 28; 72-81
2300-5599
Pojawia się w:
Acta Innovations
Dostawca treści:
Biblioteka Nauki
Artykuł

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