Browsing by Subject "drying"

Now showing 1 - 4 of 4

Access status: Open Access ,
An assessment of the effectiveness of physical curing methods of molding sand bonded by binders based on starch and aluminosilicates
(2015) Kaczmarska, Karolina; Grabowska, Beata; Drożyński, Dariusz; Kurleto, Żaneta; Szymański, Łukasz
In this study, the effectiveness of curing methods by conventional heating and innovative microwave curing were compared, based on the results of determining molding sand selected properties such as permeability, tensile strength, and wear resistance. The tested molding sand used for our research was a composition of silica sand with a commercial binder in the form of Albertine F/1 (Hüttenes Albertus). This binder is a mixture of water-swellable starch derivatives and aluminosilicates. Binding in the molding sand occurred via solvent evaporation from the samples (water).The obtained results showed a dependence of molding sand properties and selected methods of physical cure, especially after one and four hours of cured-sample storage. However, after 24 hours of sample storage (as apparent from the analysis of the obtained results), both curing methods used were almost equally effective, and marked differences in the molding sand properties were located in the range of measurement uncertainty. Using electromagnetic waves in the microwave range made it possible to significantly reduce the time of curing as well as the energy consumption of the drying process.
Access status: Open Access ,
Microwave beneficiation of brown coal
(2007) Zimmermann, Erik; Niemann-Delius, Christian
Coals of the Rhenish lignite mines, designated for power plant utilization, were exposed to microwave radiation energy for different time periods and energy levels, varying from 2,5 kW up to 10 kW, in order to dry the coal. The samples were treated with microwave radiation with a frequency of 2,45 GHz. A batch- as well as a continuous drying simulation and a verification with pre- dried samples (70 degrees of Celsius for 24 h), were conducted on a pilot scale level industrial microwave oven. To prove the general viability of microwave radiation as a beneficial process for brown coal, basic coal properties such as moisture content, volatile matter and gross calorific value were analyzed. Results show, that nearly no decomposition of the coal takes place, the moisture content can be reduced to a suitable level for pulverized coal firing power plants, the gross calorific value increases and double energy input leads to halved drying times. Furthermore the temperature of the brown coal did not exceed 90 degrees of Celsius during exposure to microwaves at ambient temperature and normal atmospheric pressure. The drying of the coal with microwave radiation showed in a first approach no negative side effects of the coal properties.
Access status: Restricted ,
Operacja suszenia i suszarnie w przemyśle ceramicznym
(AGH. Uczelniane Wydawnictwa Naukowo-Dydaktyczne, 2003) Piech, Jerzy
Access status: Open Access ,
Suszenie Parą w Złożu Fluidalnym pod Ciśnieniem (SPZFC) i oddzielanie dwutlenku węgla przez płuczkę gazową - nowe wyzwanie dla wytwarzania energii elektrycznej z węgla brunatnego
(Wydawnictwa AGH, 2011) Lechner, Stefan; Rombrecht, Hans-Bernd; Krautz, Hans Joachim
The protection of the climate requires the separation and discharge of carbon dioxide proceeding from lignite fired power plants. One measure to achieve this objective is the scrubbing of the flue gas. This process demands a high energy input in form of heating steam of a pressure of ca. 4 bar. A further measure to decrease the carbon dioxide emissions and increase the profitability of the power plant is the predrying of the lignite. A recent process is the Pressurized Steam Fluidized Bed Drying (PSFBD). Due to the high pressure the equipment is smaller than in atmospheric dryers and the steam coming from lignite water has a temperature range between 140 and 160 degrees of Celsius. The integration of this heat in the power plant process is a task still to solve. The combination of drying and gas scrubbing allows the use of the entire heat coming from the dryer in the gas scrubber where nearly 40% of the heat demand in the desorber can be substituted. By this means the necessary heat which has to be got after the intermediate steam turbine is significantly reduced. The overall power plant efficiency rises. The paper gives an overview about the state of the PSFBD-research and discusses possibilities of the use of the this heat in the desorber of a flue gas scrubber.