Rotary Burner Research Articles

Novel Design for Rotary Burner for Low-Quality Pellets

The burning of low-quality fuels causes several problems in the operation of combustion equipment, which can negatively affect the equipment’s efficiency. The possibilities for the burning of pellets made from low-quality raw materials are limited mainly by the fusibility of the ash, which settles and melts on the surfaces of the burner, gradually causing it to clog. Smelted ash also causes a decrease in heat transfer efficiency, which negatively affects the overall efficiency of the heat source. A possible solution is provided by burners with a rotating combustion chamber, where the contact time of the molten ash with the walls of the burner is shortened, and thus there is no significant melting of the ash in the burner. This manuscript is dedicated to summarizing the current state of development of burners with a rotary chamber, presenting a novel design for such a burner, and providing an analysis of that design. To conclude, the results of experimental measurements on a classic burner and a burner with a rotary chamber are presented, including a comparison and evaluation mainly in terms of emissions. The novel-designed rotary burner achieved a higher heat output than the retort burner, but a similar thermal efficiency. The rotary burner produced 32.5% lower CO emissions, 12.5% higher NOx emissions, 23% lower OGC emissions, and 44.7% higher PM emissions in comparison with a retort burner under the same conditions. This novel rotary burner concept could, after optimization, be a suitable option for efficient combustion of alternative biofuels.

Detailed assessment of specific exergetic costing, energy consumption, and environmental impacts of a rotary kiln in cement industry.

Türkiyeis one of the biggest developing countries and the second biggest cement exporter in the world. In 2021, the country exported around $1billion of cement, which is responsible for over 8% of emissions globally. In order to fulfill the EU norms, energy, emissions, and cost reduction investments continue in the country. The aim of this paper is to perform a detailed exergoeconomic assessment of a rotary burner to increase the energy and exergy performance and decrease energy consumption, exergy costs and environmental impacts of a real scale cement factory in Türkiye. During the 2-year period, detailed data has been obtained from the factory by real time detection of clinker manufacturing process. By applying the specific exergy costing (SPECO) method, energy and exergy destructions, and exergetic cost distributions for the rotary burner are calculated in detail. The 1st and 2nd law efficiencies of the overall factory, specific energy (SEC) and exergy (SExC) consumption, and SPECO for clinker production are calculated to be 59.84%, 39.04%, 4786.75MJ/ton, 5230.38MJ/ton, and 10.11 $/MJ, respectively. The use of magnesia-spinel composite refractory bricks and the anzast layer formation decreased the SPECO by 2.71% corresponding to a saving of $2,280,000 preventing 13.74 MtCO2 emissions yearly.

Energy performance of a rotary burner using pellets prepared from various alternative biomass residues

Alternative biomass makes up a considerable portion of the waste from biomass processing in forestry and agriculture. The aim of this work was to create pellets from several sources of alternative biomass, e.g., lawn clippings, corn husks, linden leaves, and pine needles, which were compared to pure wood pellets. Analysis of the fuel properties focused on their chemical composition, thermogravimetric analysis, calorific values, and ash melting temperatures. The power and emission parameters of the fuels were determined via an automatic pellet boiler. The primary issues in the combustion of the alternative biomass types were low calorific values, increased emissions, high ash contents, and low ash melting temperatures. The two primary options for solving these problems are the production of fuel mixtures with wood or the use of new combustion technologies. This work also dealt with the combustion of alternative biomass via a rotary burner. The results showed an increase in the ash content of the alternative biomass, which also led to the burner occasionally going out due to clogging with the accumulation of ash and sintering. Based on the results, only pellets from pine needles and corn husks can be recommended for further use.

Numerical and experimental methods in development of the novel biomass combustion system concept for wood and agro pellets

This paper presents the research on improving combustion of wood and agro pellets in domestic hot water boilers. The novel biomass combustion system concept consisting of rotary burner and two types of combustion intensifiers is proposed, with the aim to allow simple application in the most of existing boilers, as well as to improve the efficiency and emissions to extent the related requirements of the relevant EU standards are met. In this regard, inclusion of the combustion intensifier based on honeycomb structure into conventional combustion system is numerically and experimentally investigated and the most appropriate placement in a furnace found. The results show that, with such implementation of the combustion intensifier, significant reductions in unburned pollutant emissions (CO >40% in case of wood pellets and >30% in case of agro pellets), particulate matter emissions (28–56 mg/mn3 at 10% of O2 in dry flue gases) and improvements in combustion efficiency (>2.6–3.7%) can be obtained. A detailed numerical analysis of the subsequent combustion process within the combustion intensifier lead to the novel combustion intensifier design, aimed at lowering manufacturing cost. Preliminary numerical and experimental results indicate similar or slightly less reduction in unburned pollutants of novel design.

Effect Analysis on Combustion and Emission Characteristics of a Rotary Burner Fueled by Biomass Pellet Fuel

A biomass pellet rotary burner was chosen as the research object, in order to study the influence of excess air coefficient on the combustion phenomenon of biomass rotary burner, the finite element simulation model of a biomass rotary burner was established, and simulation results of a biomass rotary burner were verified by the experiment. The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in a steady-state condition, and the effect of excess air coefficient on temperature field and component concentration field in biomass rotary burner was analyzed. The results show that the flue gas flow rate inside the burner gradually increases with the increase of air velocity, the area with large temperature is mainly concentrated in the middle region of the rotary burner, and the maximum combustion temperature also appeared in the middle region of the combustion chamber, and the formation area of CO decreases with the increase of excess air coefficient. CO2 is mainly concentrated in the middle region of the burner, and the CO2 generating region decreases with the increase of excess air coefficient. The experimental value of the combustion temperature of the biomass rotary burner is in good agreement with the simulation results.

Analytical Determination of Torch Characteristics of Rotary Kiln Burners

Fuel combustion processes play an important role when firing materials in rotary kilns. In this paper, we provide brief information on the design and operation principle of the burner with a combined combustion system that was developed specifically for the new rotary kiln for burning chamotte. The computer modeling results of the natural gas combustion process performed in the ANSYS software package are presented.

Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.

Investigating the effect of engine speed and flight altitude on the performance of throttle body injection (TBI) system of a two-stroke air-powered engine

Two-stroke engines are one of the most commonly used engines for unmanned aerial vehicle (UAV) propulsion, which has benefits such as high power, low fuel consumption. Before, most of the two-stroke engines used in UAVs were the carburettor, but nowadays, carburettor engines are not suitable for UAVs because of stringent standards such as high flight endurance, tolerance of extreme environmental conditions. Also, the solution to meet these expectations is the use of electronic fuel injection systems. In this study, the performance of the fuel injection system in the throttle body injection (TBI) of the two-stroke air-powered engine with the capacity of 30 cc used in the UAV is investigated. Therefore, the performance of the TBI system and the engine is simulated using the lotus engine simulation (LES) software. The obtained results (mass flow rate of air and fuel, the pulse width of the injector) are used as the initial and boundary conditions of numerical simulation of the TBI system using computational fluid dynamics (CFD) to simulate and check the airflow and fuel injection in the TBI system. Design features pressure drop in the throttle body, turbulence, speed-pressure distribution in flow, fuel injection and droplet distribution, and mixing them with air, were analysed in the TBI system. First, the air flow is simulated in a Samorfeld rotary burner; where the k−w SST turbulence model is found suitable for airflow modelling in the throttle body. In the next step, to validate the fuel injection modelling, a non-reactive fuel spray was simulated in Sandia burner, and it is observed that the results of fuel injection modelling using the Kelvin–Helmholtz and Riley–Taylor failure model were well-precise to verify the hypothesis and models used. Then the performance of the TBI system was simulated in various operating conditions (1000, 3000, 6000 and 9000 RPM, flying heights of 0 to 20,000 feet). The results of the study of the effect of engine speed on the pressure drop and turbulence intensity of the flow turbulence showed that with the increase in engine speed from 1000 to 9000, the intensity of the turbulence of the flow in the throttle body was increased. Also, with the increase in engine speed, the power of the recycling area was increased. According to the results, the air pressure in the throttle body will decrease with increasing the height. In the study of the effect of the engine speed on the fuel injection characteristic, it was observed that in the 30 degrees throttle and the high speed due to the presence of strong recycling area, the turbulence intensity was high, and the deviation of the droplets from the direction of injection and the dispersion of droplets was also higher.

Operational Reliability of the Rotary Cup Burner Type Saacke - SKV 60 of Marine Boiler

One of the steps in predicting the reliability of a system includes determining the failure rate of the system’s components. The latter is obtained on the basis of the data available to the manufacturer, experience in using similar systems, using statistical methods and technical literature. In practice, the starting point in the process of foreseeing the reliability of any technical system is the assumption of constant failure rates. The system components’ failure rates which are determined in this way represent the so-called nominal values. This value is commonly modified by taking into account operation loads and environment conditions under which the observed system component is supposed to operate. In most cases the quantitative values of these two factors result from the engineering assessment that is based on the data available to the manufacturer or the user and takes into account the inevitable effect of a number of subjective factors. Predicting reliability is a process of determining numerical values which show the probability that machinery or engine will meet previously set requirements. The basic objective of reliability prediction is to ensure timely maintenance. This paper discusses predicting the operational reliability of the rotary cup burner type SAACKE - SKV 60 in the marine steam boiler TPK/VIC 8.5/7.

Reducing energy consumption of a raw mill in cement industry

Several grinding methods are available in cement industry depending upon the material to be ground. In cement production process, about 26% of the total electrical power is used in grinding the raw materials. During grinding process, the energy obtained from the rotary burner is consumed. In this study, the first and second law analysis of a raw mill is performed and certain measures are implemented in an existing raw mill in a cement factory in order to reduce the amount of energy consumption in grinding process. The first and second law efficiencies of the raw mill are determined to be 61.5% and 16.4%, respectively. The effects of ambient air temperature and moisture content of raw materials on the performance of the raw mill are investigated. The data collected over a 12-month period indicate that first and second law efficiencies of the raw mill increase as the ambient temperature increase and the moisture content of the raw materials decrease. The specific energy consumption for farine production is determined to be 24.75 kWh/ton farine. The use of an external hot gas supply provides 6.7% reduction in energy consumption corresponding to a saving of 1.66 kWh per ton of farine production.

SPRAY CHARACTERISTICS OF AN AIR-DRIVEN ROTARY ATOMIZER WITH A DOUBLE-LAYER CUP FOR USE IN AN INDUSTRIAL OIL BURNER

An experimental investigation of spray characteristics in a rotary burner with an air-driven double-layer cup atomizer is reported. The air stream generated by a centrifugal blower was used to rotate a vane propeller attached to the double-layer cup, and to assist disintegration of liquid sheets formed from the rim of the double-layer cup at the air nozzle exit. As the blower power increased, the rotational speed of the cup and the gas-to-liquid mass ratio (GLR) increased, and the atomizing crossflow velocity at an annular slot increased as well. For some given operating conditions, the effect of the crossflow velocity on the spray quality was investigated by varying the outer diameters of the air nozzle (88, 83, and 79.5 mm). The spray cone angles were measured by analyzing stroboscopic images. As the air velocity at the annular slot increased, the spray cone angle decreased. The spray radial and streamwise dispersion distributions were obtained by two liquid-collecting devices. The crossflow velocity at the annular slot, the GLR, and the diameter of air nozzles had an impact on the drop sizes and size distribution. The drop sizes of the spray were obtained using laser diffraction spectroscopy. The spray performance was described in terms of Sauter mean diameter (SMD), maximum drop diameter, relative span factor, and some representative drop diameters such as D0:9, D0:5, and D0:1. The SMD and maximum drop diameter were correlated with liquid Weber number (WeL) only. The atomization quality was improved with increasing GLR and crossflow velocity at the annular slot.

Investigation of liquid fuel combustion in a cross-flow burner

A rotary swirl burner was employed for liquid fuel spray combustion in a cross-flow stream of air. The effect of fuel spray orientation on mixing dynamics with the swirled air was investigated for different nozzle angles, including -45°, 0°, and 45°, respectively, with a variable portion of the air (from 0 to 100 per cent) allowed to flow aligned with the spray without swirl. The effect of swirl on CO and NO x emissions was found to be dominated by the competitive influences of improved mixing and increased kinetic rates. For cross injector alignment with air, NO x emissions were reduced by increasing the co-current air flowdue to the improved premixing effect, while for inclined alignment its emissions exhibited a reduction by supplying enough air to the spray lee side. High swirl intensity (swirl number up to 12) and co-current/cross-flow combination produce a reduction in the unburned hydrocarbons. The enhancement in flame radiation output with swirl was pronounced by an increase to 1.9 times the output without swirl. Inserting a porous medium at the burner exit, increased the enhancement to 4.18 times and promoted droplet evaporation. Enlarging the re-circulation zone beneath the fuel injector to a certain extent improved mixing and combustion efficiency.

Thermodynamic Analysis of Some Industrial Applications with Variable Ambient Conditions

In this study, the general exergy balance equation of an open system is obtained based on the variable ambient temperature and pressure. Using this result, the mathematical equations regarding both the reversible work given to the system in the electric arc furnace used in steel production and the exergy loss in the rotary burner used in cement production are derived. In obtaining these equations, it is assumed that the ambient temperature has a sinusoidal variation. The effects of varying ambient parameters on calculated exergy values in industrial applications are discussed, and the obtained results are analyzed and demonstrated.

Energy and exergy analyses in a rotary burner with pre-calcinations in cement production

Cement production facilities are often located in rural areas and close to quarries, where the raw materials required for cement production are present, i.e. limestone and shale. Although energy analysis, based on the first law of thermodynamics, is used to reduce heat losses or enhance heat recovery, it does not give any information on the degradation of energy that occurs in the process. Exergy analysis, based on the first and second laws of thermodynamics, facilitates improvement of the operation or technology by clearly indicating the locations of energy degradation in the process. In this study, the applications of energy and exergy analyses are examined for a dry system rotary burner (RB) with pre-calcinations in a cement plant of an important cement producer in Turkey. The RB includes thermal and chemical processes. Besides, real figures of the cement factory have been used in this work. In conclusion, the values of the first and second law efficiencies have been found and compared.

Weed Control in Arid Southwest

The Rio Grande Project, New Mexico-Texas, maintaining over 1,000 miles of waterways, has found that a weed program of its size must utilize many methods of control and presently operates under a program which includes mechanical methods, burning and spraying operations of about equal magnitude. Specific problems involved are right-of-way encroachments, air and stream pollution, crop and crop land contamination, public endorsement, odors, and safety. General weed infestations include johnsongrass and curly dock in the distribution system with salt cedar and willow in the drainage system and reservoir areas. Basically, weed control in the distribution systems is accomplished with rotary mowers, propane burners and application of nonselective herbicides. Control of weeds in the drainage system is done with brush cutters, dragline and application of selective herbicides. Phreatophytes in reservoir areas and flood plains are maintained with rotary mowers, brush cutters and application of selective herbicides.

Hot-mix asphalt paving batch plant

Hot-mix asphalt paving plant operations and the associated air pollution control problems are presented. Field observations and test data are included for full scale installations. Comparisons are made for various types of control equipment and their effectiveness. The dry cyclonic units offer the least cost expenditures, lowest space requirements, and can collect the fines in a usable condition. Wear can often be a problem, and their efficiency capabilities limit their use as total collection devices. They no longer are suitable as total collection units in many localities. Their role is being relegated to that of primary and secondary collectors. Wet collectors of several types, particularly the more sophisticated and high energy units, are capable of satisfying higher efficiency requirements. They offer space advantages and are in the medium cost range. Wear is generally no problem, however, corrosion can be a problem depending on the amount of sulphur in the rotary dryer burner fuel. Settling tanks, p...