Mass And Energy Balance For Fixed Bed Incinerators A case of a locally designed incinerator in Tanzania (original) (raw)
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THEORETICAL DESIGN OF A NON-ENERGY RECOVERY INCINERATOR FOR AWKA MUNICIPALITY
Waste management in Awka, the Capital City of Anambra State, Nigeria is the principal function of the Anambra State Waste Management Agency. Waste disposal practices in the area are mainly by open dumping and open burning which constitute serious health hazards to the residents and the environment. Use of well designed incinerators and well-built landfills are yet to attract some interest in the said area; probably because of the huge costs of equipment procurement and the expertise involved. The study aimed at designing a hypothetical non-energy recovery incinerating system for municipal solid waste generated in Awka Municipality. The incinerator is rated at a capacity of 45 tons/day, with a charging rate of 5.625 tons/hr. The relation between the refuse and the flue gases and the amounts of water and air required for complete combustion of the refuse and the necessary steps taken to ensure emission of clean gas through the stack are presented. Various assumptions were made which informed the design of the facility's combustion chambers. The materials flow/balance analyses are presented. It is hoped that this hypothetical design will provoke some interests that would lead to actual fabrication of the designed municipal solid waste incinerator for Awka urban area of Anambra State.
International journal of engineering research and technology, 2017
Waste incineration process involves chemical reaction of organic constituents with oxygen to produce flue gases, heat energy and other residues. The flue gases may contain heavy metals which have become a threat to human health and other living organisms. The study investigated the effects of varying: moisture content; loading rate; operating temperature and types of waste on incineration performance – composition of emitted flue gases (carbon monoxide, carbon dioxide and hydrocarbon) including oxygen depletion levels. Samples of waste were weighed and placed centrally into the combustion chamber and ignited. The gas pick-up probe was connected at the chimney to pick the flue gases for analysis. Incinerating wastes with moisture content of 65, 45 and 25% yielded mean carbon dioxide emissions of 10, 7 and 5%, carbon monoxide at 7, 5 and 4 ppm and hydrocarbon at 916, 730 and 618 ppm, respectively. Waste incineration at loading rates of 45, 30 and 15 kg yielded carbon dioxide of 10, 8 ...
DESIGN OF MUNICIPAL SOLID WASTE INCINERATOR FOR USE IN SEMI-ARID REGIONS
The paper treats the design of a municipal solid waste incinerator suited to the semiarid regions with northern Nigeria and Niger Republic in West Africa as the study area. Proximate and ultimate analyses results from the solid waste were used as basis for calculations, using standard formulas and correlations. The calorific value of the solid waste samples in the study area is not high enough to sustain an incineration process and it ranges from 5.024 MJ/kg to 5.867 MJ/kg. For these types of low calorific value fuels, the parallel flow concept was found to be the appropriate type of incinerator. The solid waste to be fed in the incinerator needs to be mixed with 50% of supplementary fuel in the form of readily available bagasse to make it up to the required lower calorific value. Major characteristics of the designed municipal solid waste incinerator were: total volume of incinerator chamber: 82.5 m 3 , length of the incinerator bed: 11m; width of the incinerator bed: 3m and height of the incinerator chamber: 2.5 m, while the suitable adiabatic flame temperature was found to be 1,587 K.
Journal of Engineering Research and Reports
In this study, a Computational Fluid Dynamics (CFD) technique was used to develop a model for the simulation and flow conditions of the incinerator. The CFD technique are based on subdividing the volume of interest, i.e., the combustion chamber (or other parts of the plant) into a grid of elementary volumes. The relevant equations of conservation (mass, momentum, energy) are then applied to each of those elements, after defining all inputs, outputs and boundary conditions. The resulting system is then integrated from start to finish, after introducing momentum, mass and heat transfer. The objective of the study was to evaluate and optimize the performance of locally available incinerators in Tanzania. The small scale municipal solid waste incinerator modelling was done by using a fluent solver. The case study of the existing incinerator at a Bagamoyo hospital in Tanzania was used as a model and the obtained values were compared with simulated results and other publications for valid...
Environmental assessment of energy production from municipal solid waste incineration
The International Journal of Life Cycle …, 2007
Background, Aims and Scope. During the combustion of municipal solid waste (MSW), energy is produced which can be utilized to generate electricity. However, electricity production from incineration has to be evaluated from the point view of the environmental performance. In this study, environmental impacts of electricity production from waste incineration plant in Thailand are compared with those from Thai conventional power plants.
Journal of Engineering Research and Reports, 2020
Solid waste management is challenging and incineration technique is more preferred to other methods in reduction of mass and volume, removal of odour and energy recovery in both industrial and residential environments. The challenges facing residents at Njokerio, Ng’ondu and Green Valley estates in Njoro, Kenya included poorly designed open-wastes collection systems, exceeding incinerator loading rates and inappropriate operating temperatures. It also include inadequate design specifications, poorly mixed solid wastes with high moisture contents resulting to high emissions of noxious heavy dense smoke. The aim of this study was to evaluate factors influencing flue gas emissions and performance of small-scale incinerators. Data collected were statistically analysed to determine trends, means, F-values and Least Significant Different (LSD) at . Wastes incineration at varying moisture contents (MC) from 15 to 75% produced mean emission values for carbon monoxide (CO), carbon dioxide (C...
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The paper presents some basics and the steps required when the design of an incinerator for heat recovery or waste treatment is being thought of. It is mostly important for designers in developing countries and students where the advanced design tools and computer modelling are not easily accessible. Waste management has become a major concern world‐wide and amidst various waste treatment methods like recycling, composting; incineration is the method that treats the non-reusable and non-organic portion of wastes. Incineration is a complex process due to the heterogonous nature of wastes. Incinerators cannot be designed properly without the knowledge of the combustion science involved and the characteristics of the wastes. Aspects of prime importance in design to be considered are: the incineration mechanisms and their selection, the grate firing systems, furnace geometries, secondary air injection, the 3Ts, the heating value or calorific value of the waste, theoretical Air to Fuel r...