scholarly journals Operating experience of Fluidized-bed Boiler for the Industrial Wastes.

1997 ◽  
Vol 51 (1) ◽  
pp. 129-133
Author(s):  
Akira Yosida
Keyword(s):  
Fluidized Bed ◽  
Operating Experience ◽  
Industrial Wastes

Retrofitting 25T/h Pulverized Coal-Fired Boiler Into 35T/h Circulating Fluidized Bed Boiler for Burning Mixture of Coal and Bagasse

2005 ◽  
Author(s):  
Han-Ping Chen ◽  
Xian-Hua Wang ◽  
Shi-Hong Zhang ◽  
De-Chang Liu ◽  
Yu-Hua Lai ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Combustion Efficiency ◽  
Economic Benefits ◽  
Pulverized Coal ◽  
Industrial Wastes ◽  
Pollutant Emission ◽  
Fluidized Bed Combustion ◽  
Circulating Fluidized Bed Boiler ◽  
Combustion Technology

In China, there are a large number of pulverized coal-fired industrial boilers, whose steam capacities are usually relatively small. These boilers can burn only high-grade coal and have low combustion efficiency. Furthermore, the combustion emissions, such as SO2 and NOx, pollute the environment severely. Therefore it is very important and urgent to adopt economically efficient and environmentally friendly technologies to retrofit these boilers. At the same time, there are many industrial wastes, such as bagasse, wood waste, rubbish, petroleum coke and so on, need burning disposal in China. Fluidized bed combustion technology is a kind of clear combustion technology, which has many advantages, such as excellence fuel flexibility, high combustion efficiency, low pollutant emission and good turndown capability etc. So, adopting fluidized bed combustion technology, retrofitting pulverized coal-fired boiler into fluidized bed boiler can realize pure burning various wastes or co-firing with coal, which should have great economic benefits and social benefits. And the application prospect of the method is also extensive. The State Key Laboratory of Coal Combustion has successfully retrofitted a 25t/h pulverized coal-fired boiler into circulating fluidized bed boiler with in-bed tubes and downward exhaust cyclone. The retrofitted boiler can burn mixture of coal and bagasse and the steam capacity reaches 35t/h. This paper presents the retrofitting measures and the operation status of the boiler after retrofitting.

PCR-DGGE analysis of denitrifying bacteria in a metallurgic wastewater treatment process

2002 ◽  
Vol 46 (1-2) ◽  
pp. 333-336 ◽  
Author(s):  
N. Noda ◽  
S. Yoshie ◽  
T. Miyano ◽  
S. Tsuneda ◽  
A. Hirata ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Precious Metals ◽  
Packed Bed ◽  
Population Diversity ◽  
Operating Conditions ◽  
Industrial Wastes ◽  
Wastewater Treatment Process ◽  
Dgge Analysis ◽  
Gradient Gel Electrophoresis

The wastewater generated from the processes of recovering precious metals from industrial wastes contains high concentrations of acids such as nitric acid and of salts. Biological nitrogen removal from this wastewater was attempted by using a circulating bioreactor system equipped with an anoxic packed bed or an anoxic fluidized bed and an aerobic three-phase fluidized bed. The system was found to effectively remove nitrogen from the diluted wastewater (T-N; 1,000–4,000 mg litre−1). The microbial population structure of activated sludge in an anoxic reactor was analyzed by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA (rDNA) fragments. DGGE analysis under different operating conditions demonstrated the presence of some distinguishable bands in the separation pattern, which were most likely derived from many different species constituting the microbial communities. Furthermore, the population diversity varied in accordance with the nitrate-loading rate, water temperature and reactor condition. Some major DGGE bands were excised, reamplified and directly sequenced. It was revealed that the dominant population in the anoxic reactor were affiliated with the β subclass of the class Proteobacteria.

Commissioning and Early Operating Experience Point Aconi Circulating Fluidized Bed, Cape Breton, Nova Scotia

1995 ◽  
Vol 13 (4) ◽  
pp. 393-404
Keyword(s):  
Nova Scotia ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Operating Experience ◽  
Current Status ◽  
Site Testing ◽  
Cape Breton ◽  
Start Up ◽  
Commercial Operation

The paper gives a summary description of the commissioning and early operating experience on the Circulating Fluidized Bed Unit at Nova Scotia Power Incorporated's Point Aconi Generating Plant. The experience quoted is limited to the boiler and auxiliaries including ash handling. Both coal and limestone characteristics have presented some unique challenges to the start-up of this unit and have required major on site testing and some field modifications to address them. The current status of the unit is given with a description of the on-going activities that will follow to complete the final commercial operation of the plant.

scholarly journals Green Process for Industrial Waste Transformation into Super-Oxidizing Materials Named Alkali Metal Ferrates (VI)

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1977 ◽  
Author(s):  
Ndue Kanari ◽  
Etleva Ostrosi ◽  
Cécile Diliberto ◽  
Inna Filippova ◽  
Seit Shallari ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Industrial Effluents ◽  
Transformation Process ◽  
Industrial Wastes ◽  
Iron Sulfate ◽  
Synthesis Process ◽  
Second Step ◽  
Sulfate Heptahydrate ◽  
Complete Control ◽  
Alkali Hydroxides

The investigation presented here features the design of a cleaner and greener chemical process for the conversion of industrial wastes into super-oxidizing materials. The waste of interest is the iron sulfate heptahydrate (FeSO4·7H2O) mainly generated through the sulfate route used for titanium dioxide industrial production. The products of this transformation process are alkali ferrates (A2FeO4, A = Na, K) containing iron in its hexavalent state and considered as powerful oxidants characterized by properties useful for cleaning waters, wastewaters, and industrial effluents. The proposed process includes two steps: (i) The first step consisting of the pre-mixing of two solids (AOH with FeSO4·xH2O) in a rotary reactor allowing the coating of iron sulfate in the alkali hydroxides through solid–solid reactions; and (ii) the second step involves the synthesis of alkali ferrates in a fluidized bed by oxidation of the single solid obtained in the first step in diluted chlorine. The chemical synthesis of alkali ferrates can be carried out within a timeframe of a few minutes. The usage of a fluidized bed enhanced the energy and mass transfer allowing a quasi-complete control of the ferrate synthesis process. The alkali ferrate synthesis process described here possesses many characteristics aligned with the principles of the “green chemistry”.

The Usage of Industrialwaste Materials for the Productionof Special Cements and Binders

1994 ◽  
Vol 370 ◽  
Author(s):  
Herbert PÖllmann ◽  
JÜrgen Neubauer ◽  
Hubert Motzet
Keyword(s):  
Fluidized Bed ◽  
Rotary Kiln ◽  
Laboratory Experiments ◽  
Fabrication Process ◽  
Industrial Wastes ◽  
Hydration Process ◽  
Power Station ◽  
Cement Production ◽  
Rapid Hardening ◽  
Calcium Sulfoaluminate

AbstractBy mixing various industrial wastes, as garbage combustion ashes, bottom ashes, fluidized bed ashes, lignite power station ashes, fume purification sulfates and sulfites and lime it is possible to produce cements and binders on the basis of alinite, calcium sulfoaluminate and belite depending on the chemical variety of used wastes.The fabrication process for these cements was studied by laboratory experiments and the different phases and properties were studied in detail. Alinite cement was already produced on a larger scale in a rotary kiln of 10m length. These cements can be used for application purposes in mining mortars, expansive cements, rapid hardening binders and in landfill technologies. The hydration process and workability can be controlled by using various additives. hus industrial wastes can be a secondary resource for special cement production.

Ceramic Candle Filter Performance at the Grimethorpe (UK) Pressurized Fluidized Bed Combustor

1992 ◽  
Vol 114 (2) ◽  
pp. 371-379 ◽  
Author(s):  
J. Stringer ◽  
A. J. Leitch
Keyword(s):  
Steady State ◽  
Pressure Drop ◽  
Fluidized Bed ◽  
Porous Ceramic ◽  
Operating Experience ◽  
Filter Element ◽  
Reverse Direction ◽  
Process Conditions ◽  
Filter Performance ◽  
Fluidized Bed Combustor

A pilot hot-gas particulate removal system, based on positive porous ceramic filters, has been tested on the Grimethorpe Pressurized Fluidized Bed Combustor facility. The filters are in the form of closed-ended tubes, 1.5 m long: These are generally called “candles.” The dust accumulates on the outside of the candles, and is periodically removed by a pulse of air into the candle interior, which then flows outward through the candle wall in the reverse direction to the normal flow of the combustion gas. The EPRI system contained a maximum of 130 candles, which is approximately equivalent to the requirement for 7 MW(e) capacity, depending on the filter-operating parameters. The filter unit operated for a total of 860 h under PFBC conditions, of which 790 h were at defined process conditions, typically 850°C and 10 bar. The amount of gas flowing through each filter element was varied, and the time between cleaning pulses also was varied. The pressure drop through each filter element rose as the dust accumulated on the outer wall, and recovered after the cleaning pulse. However, the post-cleaning pressure drop does not recover to the original clean candle value, but increases with time. It is believed that a steady-state value is attained, but the exposure in the Grimethorpe test series was insufficient to establish this unequivocally. During the test, five candles failed. This appears to have been due to mechanical shock, as a result of candles lifting because of excessive pressure differentials across their support plate, and dropping back. The failures are not believed to be intrinsic to the technology. However, in addition a reduction in the strength of the candles with time of exposure was observed. This might also attain a steady-state value, but this too could not be established on the basis of the tests reported in this paper. This is clearly a matter of importance, and further work will be required to determine the suitability of the clay-bonded silicon carbide medium used in these tests for this application. A number of deficiencies in the design of the unit emerged with the operating experience, and suggestions have been made for improvements. However, it is clear that further work on design optimization is required. The pulse-cleaning air usage in the tests was greater than would be economically acceptable in a practical system. Further work needs to be done to optimize the cleaning cycle. Overall, the test was very successful, and, when operating properly, the filters removed essentially all of the dust in the gas exiting from the combustor. Apart from the issues with the candle strength and the pulse-cleaning air usage, the other problems were not believed to be of major importance in the further development of the technology. This paper will summarize the test results, emphasizing the problems of candle durability and the pulse-cleaning system.

Operating experience with lined cyclones in vessels with a fluidized bed

1981 ◽  
Vol 17 (5) ◽  
pp. 259-261
Author(s):  
D. M. Soskind ◽  
E. Ya. Barsukov ◽  
G. I. Zavelev ◽  
G. A. Efremova ◽  
V. V. Meshcheryakov ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Operating Experience

Industrial Wastewater Treatment Using Anaerobic Fluidized Bed Reactors

1983 ◽  
Vol 15 (8-9) ◽  
pp. 169-176 ◽  
Author(s):  
John S Jeris
Keyword(s):  
Wastewater Treatment ◽  
Fluidized Bed ◽  
Industrial Wastewater ◽  
Anaerobic Treatment ◽  
Industrial Wastes ◽  
Positive Energy ◽  
Fluidized Bed Reactors ◽  
Sludge Treatment ◽  
Detention Time ◽  
Positive Energy Balance

Pilot plant results of anaerobic treatment using granular biological fluidized bed treatment for a number of industrial wastes is presented. Wastes containing from 5,000 to 54,000 mg/ℓ, were treated with 65 to 95 percent COD removal in 0.3 to 4.9 days hydraulic detention time. Organic loadings of 3 to 38 kg COD/m3-day were used. An energy comparison showed anaerobic treatment to produce a positive energy balance compared to an energy need for comparable activated sludge treatment.

scholarly journals Experimental Study of Stabilized Soil Utilizing Circulating Fluidized Bed Combustion Desulfurization Ash with Carbide Slag and Desulfurization Gypsum

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Dezhi Shao ◽  
Jinlong Liu ◽  
Xin Huang
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Composite Foundation ◽  
Industrial Wastes ◽  
Fluidized Bed Combustion ◽  
Soil Mixing ◽  
Carbide Slag ◽  
Stabilized Soil ◽  
Cement Soil ◽  
Circulating Fluidized Bed Combustion

This paper discusses the feasibility of preparing soil stabilizer which is circulating fluidized bed combustion ash-based, supplemented with carbide slag and desulfurization gypsum, composed entirely of complete industrial wastes. The results show that CFBC ash has better pozzolanic activity than fly ash. When stabilizer total content is 10% and the ratio of CFBC ash : carbide slag : desulfurization gypsum is 7.2 : 1.8 : 1, compressive strength of stabilized soil can reach the maximum of 2.12 MPa at the age of 28 d of curing. Stabilizer can meet the strength requirements of cement-soil mixing pile composite foundation and cement-soil mixing pile waterproof curtain.

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