Firstly, the current foodstuff drying methods are carefully performed in Puyi, Chahe, and Gusheng (Fig. 1, Fig. 2 and Fig. S1), such as burning mixed coal in open stove (MC + OS), lump coal in open stove (LC + OS), coal washing wastes in open stove (CWWs + OS), fuelwood in open stove, sundrying (Table S1) and honeycomb briquettes (HB) in IS.
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The effective parameters are evaluated in three categories as follows: (1) the parameters about the drying media (the type of the media, the temperature, the pressure, the velocity and the relative humidity), (2) the coal parameters (the type of the coal and the size) and (3) the drying method. Keywords lowrank coal lignite drying
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Refined coal is the product of the coalupgrading technology that removes moisture and certain pollutants from lowerrank coals such as subbituminous and lignite (brown) coals, raising their calorific values. [1] Coal refining or upgrading technologies are typically precombustion treatments and processes that alter the characteristics of coal ...
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However, dry coal preparation methods, which do not create the same disposal challenges as slurry waste, can be effective in areas where the water supply is restricted. Currently, most coal preparation plants recover fine coal only from the size fraction greater than 100 mesh (150 micrometer). Typically, this is done with wateronly cyclones ...
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The VNIIMT tested a coal drying method based on a solid heattransfer medium (for example, metal balls). This method considerably speeds up the drying process due to the large heattransfer area between the solid medium and the small particles. This reduces the length of the drum dryer to onehalf or even onethird of the original length and specific heat consumption.
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application of the new moving bed coal moisture control device in coal predrying technology. 2. Materials and Methods Coal Sample The coking coal used in this study is from Xingtai City, Hebei Province, China, and it was obtained after the coal blending process. Liu et al . found that the fraction below mm was dominant
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Few studies reported that the solar drying method can be chosen for drying the wet bagasse before feeding into the furnace for combustion (Phadkari et al., 2017, Subahana and Natarajan, 2016). Phadkari et al. (2017) developed an FCSD setup for solar drying of bagasse pulp where 1000 g of bagasse fibers were dried. The proposed dryer was useful ...
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The drying process comprises three stages: heating, flash evaporation, and residual heat drying. A multistage energy model is established to elucidate the moisture removal mechanism. The results show that the transient drying effect improves with increasing temperature/pressure.
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Microwave drying method decreases the coal moisture content from 52% to 10% [3]. Microwave . drying is a form of indirect heat ing because it uses electromagnet ic waves to gen erate heat in a n on
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Coal spontaneous combustion (CSC) is a complex physical and chemical process. Numerical simulation is an efficient method for visualizing and quantifying CSC. However, in previous models, the property parameters of coal are frequently assumed to be constant and hence cannot be used to predict accurately the thermodynamic behaviors during CSC. In this study, a fully coupled porous media model ...
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Bituminous. The next stage of coal is hard and a shiny, smooth black color, with a high Btu rating. It also contains a sticky substance known as bitumen, which is used when making asphalt, but this sticky coal makes it tricky to undergo coal drying processes before being burned. Much of this coal is used for energy production as it does not ...
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Drying fruits and vegetables is an ancient method used for food preservation. Apart from the agricultural sector, there are many industries such as automobile, rubber, paper and pulp, sugarcane, wastewater treatment, lignite/coal, etc. require heat energy for drying during production processes. Conventional energy sources such as coal, natural ...
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Department of Energy Office of Scientific and Technical Information. Search terms: Advanced search options. ...
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After t hermal drying methods, distillation methods are the next most commonl y used [9]. In these procedures, coal is heated in a liquid that has a bo iling point higher than that of water and is ...
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Alternate Drying Methods Dry the lignite using the "waste" heat from a light bulb. This method will model Coal Creek's use of waste heat from its boiler. Simply place the lignite in a sunny window and let it dry. Weigh the sample each day until the weight is constant for two days. No matter which drying method is used, have students ...
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Modelling and calculation methods Description of the coal drying process The configuration of the coal drying system is schematically shown in Figure 1. The coal drying system consists of two major components, drying reactor (DRYREAC) and gassolid separation unit (SEP). The wet coal with 25 wt% of initial moisture (1) is heated by the hot ...
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The less accurate moisture estimation mentioned above for the dry coal samples with equal to or less than 12 wt.%H 2 O could be improved by the following advanced methods. (i) The use of the multiexponential model (Liu et al. Citation 2020 ) instead of the monoexponential model, Equation Eq.
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Coal must also be dried for the following processes: (1) briquetting, (2) coking, (3) gasication, (4) lowtemperature carbonization, (5) liquid fuel synthesis, and others. The nal moisture...
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Drying of materials is an important and essential mechanism during the production process in industries. Drying fruits and vegetables is an ancient method used for food preservation.
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A coal drying system was modelled and the calculation methodology was developed to calculate the system. Then the system performance was obtained and the exergy destruction and loss in the system ...
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The repression of oxidation processes during drying should occur in the case of methods #1, #2 and #3, whereas possible oxidation of coal is expected in procedures #4 and #5. The medium vacuum used during experiments #1 and #3 was provided by an oil pump. For the drying experiments, about 2 g of coal were used. The effort was to obtain a dry ...
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Depending on the coal drying method and the method of recovering heat from the vapours in the power plant system, an up to 5% increase in power unit efficiency can be achieved [61, 67, 78]. An additional effect of the higher power unit efficiency is a reduction in CO 2 emissions. The power unit efficiency can be further increased by adopting a ...
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Solar Drying: Solar drying uses sunlight to evaporate moisture from coal. It is an ecofriendly method, but it may not be as efficient as thermal drying methods, especially in regions with limited sunlight. Microwave Drying: This method utilizes microwaves to heat the coal and evaporate moisture. It can be a rapid and efficient drying process.
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An efficient dry coal cleaning method can offer a solution while avoiding problems associated with wet methods and generates partially dried coal. Air dense medium fluidized bed (ADMFB) can be an ...
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The experimental results show that air drying, which reduces the free radical concentration of the coal, causes a decline in its oxygen reactivity whereas thermal dewatering, which causes an increase in the free radical concentration of the coal, enhances its oxygen reactivity.
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Highlights. Lignite predrying methods were compared in terms of their contribution to the plant thermal efficiency. The theoretical model for thermodynamic analysis of predried lignitefired power plant was established. The steam predrying has higher potential in plant thermal efficiency improvement than flue gas predrying. Main factors ...
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In addition, the traditional preparation method is supercritical drying, which is complex and has safety issues. Here, we successfully prepare a SiO2Al2O3 aerogel utilizing coal gangue as a raw ...
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The analysis presented here looks at the addon benefits of coal drying at the mine end relative to drying at plant sites, but is agnostic as to the particular coal drying technology employed. The issue is examined in the Indian context, but the findings are applicable elsewhere. It is well known that moisture is a major cause of thermal losses ...
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That method took the form of drying and pressing brown coal at the von der Heydt mine in Ammendorf, Germany, with a patent for a pipe dryer to dry brown coal first being registered in 1884. As an ...
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rising hot gases. In the flash dryer, coal is fed into a stream of hot gases for instantaneous drying. The dried coal and wet gases are both drawn up a drying column and into a cyclone for separation. In the multilouvered dryer, hot gases are passed through a falling curtain of coal, which is then raised by flights of a specially designed conveyor.
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Microwave drying is an expensive drying method but its combination with conventional drying methods such as fluidized bed drying is a very promising and energy efficient technology, especially when applied at the falling rate period of coal drying when two thirds of the time may be spent on removing the last one third of the water (Fig. 1) [9].
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Coal drying. Coal preparation plants that employ fine coal cleaning by froth flotation can produce an unacceptable amount of moisture in the product. Thermal drying, in which the wet coal is dried in the hot gas generated by a coalor gasfired burner, is used in some plants to reduce the moisture content. Refuse and tailings management.
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The drying rate curve of the thinlayer drying ex periment of 2 cm thick coal under different heat source temperature is shown in Figure 7. The abscissa in t he figure is the moisture content of coal,
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Abstract. The overall objectives of this study are to develop an NMR method for measuring the water in coal, to measure the changes in coal structure that occur during coal drying, to determine what effect water has on retrograde/condensation reactions, and to determine the mechanism by which water may enhance coal reactivity toward liquefaction.
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Currently, coal predrying process has been broadly applied in lignite applications for power generation, due to the insufficient pulverizing throughput and the huge investment expenditure of the boilers [9]. ... Compared with the evaporative drying, this new method can increase the drying rate and reduce the energy consumption. View all citing ...
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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