Incinerator Design Research Articles

Mechanism of Working Fluid Circulation in the Multisource Organic Solid Waste Incinerator

Garbage incineration power generation is utilized to dispose of multi-source organic solid waste. This work constructed a mathematical model for a 750 t/d garbage incinerator to reveal the coupled response between the boiler and furnace sides. Field experiments validated the model, exploring various operating conditions including different loads, fuel blending ratios, primary air, and internal flue gas recirculation (IGR) air flow rates. Increasing the load by 9.1% raised furnace heat exchange by 4.0% but reduced economizer heat exchange by 19.0%. Introducing waste cloth strips and paper mill waste enhanced furnace water-cooled wall heat transfer but reduced economizer heat exchange. A 10.8% rise in primary air flow increased superheater heat exchange by 7.8%. Similarly, a 21.3% rise in IGR air flow increased economizer heat exchange by 9.0%. The temperature rise and enthalpy rise in the superheater were higher when the low calorific value of the fuel was higher. Increasing primary air velocity enhanced heat transfer, raising the outlet temperature of the medium-temperature superheater, necessitating an increase in secondary water spray to adjust the outlet temperature of the high-temperature superheater. This work provides guidance for the design and practical operation of multi-source solid waste incinerators.

On the Impact of Non‐CHO Elements on Fuel Properties in Waste Incineration

AbstractIncineration is and will remain a proven technology for the safe and sustainable destruction of environmentally hazardous substances. The behavior of non‐CHO elements during combustion plays an important role in the design of incinerators for hazardous waste since they drive the selection and design of the process sequence and of the single equipment. This contribution presents an overview on impacts of the presence of non‐CHO compounds in waste incinerators and provides correlations to estimate the product distribution of sulfur‐ and halogen‐containing compounds as well as for the important fuel properties oxygen demand and heat of combustion of material containing non‐CHO elements.

Influence of main operating parameters on the incineration characteristics of municipal solid waste (MSW)

To study the influence of the main operating parameters on the incineration characteristics of municipal solid waste (MSW), a 375 t/d mechanical grate incinerator is selected as the research object, and the effects of primary air temperature, secondary air arrangement, and grate speed on the MSW incineration process are simulated, and experimental tests are carried out under different primary air temperature and grate speed conditions. The results show that the relative errors between the measured and simulated values of the incinerator outlet O2 content and the measurement point temperature are within ±5% for all test conditions. When the primary air temperature increases from 423 K to 503 K, the position where the MSW incineration ends moves 3.32 m towards the front of the grate, and the moisture evaporation and fixed carbon combustion rates also increase, but the maximum volatile release rate and the optimal incineration condition of the MSW occur at the primary air temperature of 483 K. The increase in grate speed delays the incineration process of MSW and decreases the moisture evaporation rate and fixed carbon combustion rate, but it worsens the incineration effect of MSW. When the grate speed increases from 6.94 m/h to 13.88 m/h, the MSW incineration process is delayed by 3.20 m, and the moisture evaporation and fixed carbon combustion rates decrease by 43 kg·m−2·h−1 and 9 kg·m−2·h−1, respectively. To achieve the optimal operating conditions, the secondary air volume ratio of the front and rear arches is 1.59:1, the secondary air direction of the front arch is 40° and 60°, and that of the rear arch is 0° for the primary air temperature of 463 K and 483 K, respectively. This study can provide useful insights for optimizing the design and operation of mechanical grate incinerators.

Design of a Novel α-Shaped Flue Gas Route Flame Incinerator for the Treatment of Municipal Waste Materials

In order to improve the combustion characteristics of municipal waste materials and reduce excess pollutants generated during the incineration process, this study develops a novel waste incinerator with an α-shaped flue gas route. This has been achieved through the application of momentum vector synthesis theory in order to modify the secondary air structure in a conventional incinerator, resulting in enhanced combustion efficiency of the incinerator. Computational Fluid Dynamics (CFD) based cold state test results demonstrate that with appropriate modifications to the design of the incinerator, the flue gas propagates through a longer α-shaped route rather than conventional L-shaped route. Hot state tests have been carried out on a full scale 750 tons/day waste incinerator. Test rests show that the temperature of the flue gas increases by 138% under the front arch when secondary air supply is being incorporated into the design of the incinerator, resulting in better combustion of the municipal waste materials, lower emissions and higher thermal efficiency of the incinerator. The results obtained in this study confirm the rationality and feasibility of momentum flow rate method for better design of waste incinerators.Graphical

Numerical simulation of the effect of the near-ground explosion of energetic materials on the shell of a vertical incinerator

In order to study the effect of the near-ground explosion of energetic materials (EMs) on the shell of a vertical incinerator, the effect of different explosion heights of EMs of 90 g TNT on the incinerator shell with different exhaust gas outlet diameters was numerically simulated in three dimensions using AUTODYN software. The simulation results showed that the maximum von Mises equivalent stress (mis. stress) of the shell occurred at the upper edge of the incinerator exhaust gas outlet. Furthermore, the maximum mis. stress of the shell increased with the decrease of the height from the TNT explosion center to the bottom of the shell and the increase of the exhaust gas outlet diameter of the incinerator. Importantly, the existence of the incinerator exhaust gas outlet and the constraint of the shell increased the critical height with the near-ground explosion effect compared to that of the unconstrained open environment (157 mm). The exhaust gas outlet diameter of the incinerator increased from 80 mm to 160 mm, and the critical height with near-ground explosion effect increased from 180 mm to 250 mm. In the design and application of vertical incinerators, the effect range of near-ground explosion can be reduced by reducing the diameter of the shell exhaust gas outlet and filling the bottom surface with a certain height of shock wave attenuation material.

Design and development of community incinerators using the CFD method

Design and development of community incinerators using the CFD method

Medical Waste Management and Design of a Low-Cost Incinerator for Reduction of Environmental Pollution in a Multi-System Hospital

Pollution of the environment and inappropriate management of medical wastes are major challenges facing developing countries and this must be tackled with recent technology for public health, enhanced natural ecosystems, and a better environment. This research is a two-step process that involves the assessment of the existing Hospital waste management practices in a multi-system Hospital in Ado-Ekiti, Nigeria. Excess air, kerosene (auxiliary fuel), single chamber, Batch-fed (Manual feeding), and controlled air incinerator were designed. Wastes were loaded once at the beginning of the combustion cycle followed by combustion, ash burnout, cool down, and ash removal to assist medical waste management. Findings revealed that personnel involved in handling medical waste were equipped with inadequate protective gear. Medical waste was handled together with municipal waste and both wastes were incinerated in an open dumpsite without engineered sanitary landfill at disposal locations constituting a nuisance with a high risk of pollution to the surrounding environment. The incinerator was designed for a waste load of 269 kg.day-1. It consists of four zones; the waste and combustion zone (2.7 m × 1.8 m × 1 m), the ash zone (0.23 m height), the combustion fumes and one-second retention zone (0.43 m height) as well as the excess air zone (0.46 m height). This low-cost medical waste incinerator has a lot of improvement, operational effectiveness, and efficiency to the currently available techniques. Viable recommendations made will improve the state of environmental health and reduce the harmful effects of medical waste.

Process Engineering Design of Tobacco wastes Incinerator with Utilization of Heat Energy from Combustion Gases

An integrated incineration unit was developed to handle tobacco waste within a processing plant in the Eastern Company, Egypt. In addition to the unit, subsequent utilization of the heat content of combustion gases was investigated. The incinerator design was tailored around the current process of solid waste combustion within the tobacco processing plants of the Eastern Company in 6th October City, Egypt. A feeding rate of 1 ton/hr of solid waste consisted of 50% mass of tobacco, 20% paper, and cartons, 20% wooden boxes, and 10% plastics. The volume occupied by the remaining ash after the incineration process would not exceed 5% of the feedstock. The overall material and energy balances were calculated based on a 25490 kg/hr combustion gas discharge with a heat content of 20.09 Gj/hr. Energy from flue gases would be utilized to generate saturated steam or produce hot water. The design included a fired-tube boiler capable of generating 7 ton/hr saturated steam at 185 °C and 10 bar. The temperature of the exhaust effluent combustion gases vented into the atmosphere had to stand at 200 °C to avoid penalties. Moreover, this effluent temperature is considered to be effective and efficient utilization of the heat content in the waste.

Design and Life Cycle Assessment of small-scale medical waste incinerator equipped with Porous Radiant Burner for remote areas

ABSTRACT In this paper, the design of a Small-scale Medical Waste Incinerator (SMWI) equipped with an LPG-operated Porous Radiant Burner (PRBLPG) is presented as a solution for disposing of medical waste generated in remote areas. Based on simple mass and heat balance analysis, SMWI having primary and secondary chambers with a volume of 1 and 0.754 m3 is designed. The proposed SMWI is evaluated for its environmental impact by performing a Life Cycle Assessment (LCA) and compared with an SMWI equipped with an Electric Heater (SMWI–EH). The total primary energy required for the construction of SMWI is 48285.56 MJ. It is found that the damage caused by the operation of PRBLPG in SMWI is lesser when compared to that of an Electric Heater (EH). In SMWI–PRB, LPG consumption contributed to about 17488.27 kg CO2−eq in the global warming category, whereas in the case of SMWI–EH, electricity consumption contributed to about 243766.11 kg CO2−eq. The operation of SMWI–PRB showed a reduction of about 54% in the resource utilisation category in comparison with SMWI–EH. The results obtained from the LCA study indicated that PRBLPG is a better option as an auxiliary heating device in SMWI than EH due to its environmental superiority.

Application of momentum flux method for the design of an α-shaped flame incinerator fueled with two-component solid waste

Kitchen waste and tree branches are two of the most common solid waste materials suitable for on-site disposal. Quantification of combustion characteristics of these waste materials is vital for designing an appropriate incinerator. In this paper, the combustion characteristics of a mixture of kitchen waste and tree branches have been analyzed. As the theoretical basis for the design of incinerator arches is severely limited in the published literature, a novel momentum flux methodology for designing α-shaped flame arches has been developed for the disposal and combustion of two-component solid waste. For this purpose, orthogonal experimental design methodology has been employed for eight different operating conditions of the incinerator. The theoretical results have been verified by cold-state experiments, resulting in the development of a novel small-scale, α-shaped flame incinerator fueled with kitchen waste and tree branches. Cold-state experimental results show that the optimum dimensionless structural parameters of the furnace arches are H1/L of 0.3, H/L of 0.5 and h/L of 0.15, with the front arch angle of 45° and the rear arch angle of 12°. For full-scale validity and commercial viability of the novel incinerator, hot-state tests have been conducted in this study.

Experimental & Numerical study on COVID-19 Waste Treatment Using a Gasification Type Incinerator: Laboratory Scale

Due to the COVID-19 pandemic, the use of personal protective equipment in the community has contributed to the increasing amount of medical waste. Medical waste from the COVID-19 pandemic is classified as infectious medical waste which is waste related to patients who need isolation from infectious diseases. one of the solutions offered is a medical waste incinerator. By studying the medical waste incinerator model in the hospital, the researchers finally took the initiative to do a simple incinerator design. the incinerator to be used is updraft gasifier type. It is hoped that the use of this incinerator will be able to solve the existing medical waste problem. In this study, the researchers use experemental approach to get the basic data from the reactor. After gain the data, then the researcher use numerical approach which is using ansys softwere to get a better look of the temperature contour on the rector. From both study, researcher can conclude tha it would take an upgrade on the existing blower to incenerate the medical waste on a safely temperature.

Design of a small scale fluidized-bed incinerator for MSW with ability to utilize HHO as auxiliary fuel

Waste incineration has become a mature technology and widely accepted due to its environment friendliness, easy operation and ability to reduce more than 95% mass fraction. There are some inherent limitations associated with incinerators such as high fuel consumption and cite feasibility. In this study, we propose a novel design concept of small scale fluidized bed incinerator for household use, with the ability to consume brown’s gas (HHO) as primary fuel for incinerate waste. In principle, the HHO gas generated through photovoltaic (PV) integrated water electrolysis system would be feed from the bottom to provide heat energy to the waste. Theoretical design of fluidized bed type incinerator has been presented with water electrolyzer system. It was calculated that 150 lph of hydrogen is required for this proposed incinerator system which can handle 5 kg of waste.

Design and Computational Fluid Dynamics Modeling for a Municipal Solid Waste Incineration Process

Municipal Solid Waste (MSW) incineration is among the important opportunities to control the pollutions caused by improper dumping and flue gas emissions so as to meet the environmental guidelines. The objective of this study was to design and develop a model for the MSW incineration process. The paper explains the design and development of MSW incinerator involving details of the Computational Fluid Dynamics (CFD) procedures through model design to the post process. CFD model was developed to reveal these features of the incineration process in the MSW incinerator. The model predicts the temperature in combustion chambers as well as at stack outlet of the incinerator. The solid waste characterization was done, and the laboratory analysis shows that, the Higher Heating Value (HHV) of the MSW is 11.65 MJ/kg on dry basis. The elemental composition MSW consists of 54.8%, 5.27%, 34.61%, 2.37% and 0.3% for Carbon, Hydrogen, Oxygen, Nitrogen and Sulphur respectively which are the input parameters for the CFD. The model simulation was positively achieved during combustion process and temperature in combustion chambers ranged between 930 K and 1700 K.

PREDICTION OF TEMPERATURE AND FLUE GASES FOR THE INCINERATION PROCESS USING MATHEMATICAL MODELING AND COMPUTER SIMULATION

Mathematical modeling and computer simulation for the municipal solid waste incineration process provides important understanding into the incinerator’s performance. The application of mathematical modeling for the incineration process will increase the incinerator operating efficiency. The broad objective of this study was to optimize the design of municipal solid waste incinerators using mathematical modeling and computer simulation. Computation Thermal Predictions (CTP) relations involving different types of incineration parameters such as temperature, density, velocity and species concentration were formulated based on theories of incineration process with various assumptions. The solution of the mathematical model developed was done and accomplished by Computational Fluid Dynamics (CFD). Finite element method of numerical analysis was applied to solve the temperatures in the simulated incinerator model as well as species/flue concentration at the end of its chimney. Dimensions used on the simulated model were applied to construct the physical incinerator for analysis. Tests were performed on the physical model incinerator and data used to validate the results obtained from the simulated model. Both simulated and experimental results showed that it is possible to forecast temperature and flue gases by the application of mathematical expressions. The incinerator CTP model was applied to simulate the incineration process and aid to regulate temperature at different locations and species/flue concentration at the end of incinerator chimney. The CTP results were very close to those obtained from experiment. The t-test method conducted revealed that simulated and experimental results did not differ significantly at 0.05 level of significance. Therefore, there is an agreement between the empirical model and experimental data as they show true trend of the incineration process.

Numerical Investigation of a Portable Incinerator: A Parametric Study

The application of incinerators for the municipal solid waste (MSW) is growing due to the ability of such instruments to produce energy and, more specifically, reduce waste volume. In this paper, a numerical simulation of the combustion process with the help of the computational fluid dynamics (CFD) inside a portable (mobile) incinerator has been proposed. Such work is done to investigate the most critical parameters for a reliable design of a domestic portable incinerator, which is suitable for the Iranian food and waste culture. An old design of a simple incinerator has been used to apply the natural gas (NG), one of the available cheap fossil fuels in Iran. After that, the waste height, place of the primary burner, and the flow rate of the cooling air inside the incinerator, as the main parameters of the design, are investigated. A validation is also performed for the mesh quality test and the occurrence of the chemical reactions near the burner of the incinerator. Results proved that the numerical results have less than 5% error compared to the previous experimental and numerical approaches. In addition, results show that by moving the primary burner into the secondary chamber of the incinerator, the temperature and the heating ability of the incinerator could be affected dramatically. Moreover, it has been found that by increasing the flow rate of the cooling air inside the incinerator to some extent, the combustion process is improved and, on the other hand, by introducing more cooling air, the evacuation of the hazardous gases from the exhaust is also improved.

Parameter design of rotary kiln incinerator and application analysis in engineering cases

In this paper, according to the type and scale of hazardous waste incineration, process selection, design of rotary kiln incinerator, and the engineering principle and performance characteristics of rotary kiln incinerator system are analysed, and the proposed method is verified by practical engineering examples. The results showed that the temperature of rotary kiln is controlled at about 850 °C, the residence time of hazardous waste in rotary kiln is about 60min, the rotating speed is 0.88r/min, and the inclination angle is 1.75. The temperature of the second combustion chamber is more than 1100 °C, and the residence time of flue gas in the second combustion chamber is more than 2S. After continuous incineration, the reduction rate of slag ignition is less than 5%, the removal rate of fly ash is more than 99.99%, and the flue gas is discharged up to the standard.

Catalytic combustion performances, kinetics, reaction mechanisms and gas emissions of Lentinus edodes

This study aimed to quantify the catalytic effects of CaO, Fe2O3, and their blend on the Lentinus edodes stipe (LES) and pileus (LEP) combustion performances, kinetics and emissions in bioenergy generation. Apparent activation energy (Ea) of LES and LEP increased with CaO, decreased with Fe2O3 and differed with their blend. The catalysts mainly affected the maximum intensity of volatiles combustion and partly the fixed carbon combustion. CaO, Fe2O3, and their blend decreased the release intensity of NOx from the LES combustion. Fe2O3 increased SO2 emission, while CaO, and the blend narrowed the emission temperature to the range of 200 to 450 °C. Kinetic triplets were estimated via the integral master-plots methods, and the best-fit reaction for the three sub-stages were obtained coupled with the model-free models. Our study provides a reference for the catalyzed biomass combustion in terms of pollution control, bioenergy generation, optimal design of incinerator, and industrial-scale application.

Design of Medical Wastes Incinerator for Health Care Facilities in Akure

Health Care Facilities (HCFs) are primarily saddled with the responsibilities of providing medical care, thus ensuring sound health of individuals. Tremendous efforts have been made by the government to ensure her availability in nooks and crannies of every community, which have resulted into improved medical services. However, among other environmental challenges confronting health care facilities in developing countries is Medical Waste generated in the course of carrying out their duties which is often ignored and in most instances treated as municipal or domestic solid waste. Effective management of medical waste requires keen planning, training and tracking throughout the waste generation, segregation, storage, collection, transportation, treatment and disposal processes. The fundamental information for selecting and designing the most efficient treatment method of medical waste is obtained by means of Waste Composition Analysis. Results from this study revealed that the daily waste generation rate of Ondo State Specialist Hospital Akure (OSSHA) and Mother and Child Hospital Akure (MCHA) was 124.5 kg/day. The hospitals’ waste consists of 81.6% combustible wastes and 18.4% non-combustible wastes by mass. The combustible wastes are paper (6.50%), textiles (14.34%), cardboard (3.88%), plastics (6.04%) and food waste (19.08%). Since the ratio of combustible medical waste is higher than non-combustible medical waste, incineration (thermal destruction) at elevated temperature under controlled operational condition is considered the best disposal option to detoxify the medical waste. In other to prevent the release of harmful gases from burnt medical waste through incinerator, a counter-current packed bed wet scrubber is designed which operates by impaction and absorption.

Mixed Waste Combustion Test Research and Calculation of Activation Energy

Thermo gravimetric combustion experiments [1] of the easy chopsticks, food bags, cotton and its mixed components were investigated, by the mixture experiment design program [2]. Then combustion characteristics curves of thermo gravimetric and thermo gravimetric differential, and each group point average activation energy [3] were obtained. Base on the average activation energy of each waste component combustion, the activation energy calculation empirical correlation which fits in various mixed waste combustion calculation can be set up through three Scheffe polynomials. In addition to the three vertices of the gravity method, which were used to conduct the mixed waste combustion test, and the results of mixed waste activation energy agree well with the activation energy calculated from the empirical correlation. Thus, the activation energy is correct. Application of this method plays an important role in the direction for the design of waste incinerator actually [4] and the waste combustion adjustment.

Numerical modeling of municipal waste bed incineration

PurposeIncineration has become increasingly important in many large cities around the world because of fast urbanization and population growth. The benefits of energy production and large reduction in the waste volume to landfills also contribute to its growing adaptation for solid waste management for these cities. At the same time, the environmental impact of the pollutant gases emitted from the incineration process is a common concern for various stakeholders which must be properly addressed. To minimize the pollutant gas emission levels, as well as maximize the energy efficiency, it is critically important to optimize the combustion performance of an incinerator freeboard which would require the development of reliable approaches based on computational fluid dynamics (CFD) modeling. A critical task in the CFD modeling of an incinerator furnace requires the specification of waste characteristics along the moving grate as boundary conditions, which is not available in standard CFD packages at present. This study aims to address this gap by developing a numerical incinerator waste bed model.Design/methodology/approachA one-dimensional Lagrangian model for the incineration waste bed has been developed, which can be coupled to the furnace CFD model. The changes in bed mass due to drying, pyrolysis, devolatilization and char oxidation are all included in the model. The mass and concentration of gases produced in these processes through reactions are also predicted. The one-dimensional unsteady energy equations of solid and gas phases, which account for the furnace radiation, conduction, convection and heat of reactions, are solved by the control volume method.FindingsThe Lagrangian model is validated by comparing its prediction with the experimental data in the literature. The predicted waste bed height reduction, temperature profile and gas concentration are in reasonable agreement with the observations.Originality/valueThe simplicity and efficiency of the model makes it ideally suitable to be used for coupling with the computational furnace model to be developed in future (so as to optimize incinerator designs).