Material Feed Rate Research Articles

Feed rate measurement technique and yield maps creating in fodder plant harvesting

The main aim of this article is to evaluate the possibility of forage yield maps creating based on mowing machine’s conditioner power input measurement. Strong spatial dependence was observed for conditioner power input data. For the data file from material feed rate measurement the medium spatial dependence was calculated. Relatively low value of variograms range is possible to explain by the type of chosen exponential model. Visual displaying of data distribution is done by the maps. These maps were plotted under kriging method. It is possible to observe distributions of higher and smaller values of conditioner power input and material feed rate measurement by this way. Plotted maps are shown in Figures. The correlation coefficients were calculated 0.419 for filtered data. It follows from this evaluation that conditioner power input measurement can be used for the determination of mowing machine material feed rate.

Modeling of spraying with time-dependent material feed rate

This paper presents a mathematical model for predicting the thickness of coatings deposited by means of spraying onto rotating parts with circular symmetry, for the case of time-dependent material feed rate. A procedure for calculating the material feed rate control law providing production of coatings with uniform thickness or coatings with a predefined law of thickness variation is developed. The proposed procedure was used to analyze the process of spraying onto the surface of a rotating disc. A material feed rate variation law providing production of uniform coatings and coatings with linear thickness variation is calculated. It is demonstrated that for the first case the optimal law of material feed rate variation is described by a linear function and for the second case it can be successfully approximated by a quadratic function. The proposed calculation technique can be easily used for the case of coatings with a more complex law of thickness variation.

Synthesis of Ni and bimetallic FeNi nanopowders by microwave plasma method

Nickel nanopowders can be synthesized by microwave plasma synthesis method. The effect of the feeding rate of the precursor material to the average particle size and crystallinity was studied. FeNi bimetallic alloy nanopowders were also successfully synthesized by pre-mixing the respective precursor raw materials before feeding into the plasma reaction zone. The Ni and FeNi nanopowders were characterized by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD).

Preparation of silver nanopowder by thermal plasma

Nano-sized silver powder was prepared from micro-sized silver powder by thermal plasma processing. As a process parameter, feeding rate of raw material was controlled by the flow rate of the carrier gas. To study the effect of the composition of plasma generation gas, He and H2 were mixed with Ar respectively. Most of prepared powder was collected on the quenching tube. Characteristics of the powders were analyzed using X-ray diffractometer (XRD), scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS), light scattering particle size analyzer (PSA), and UV/Visible spectroscopy. Under Ar plasma, raw powder was not completely evaporated, forming a bimodal structure. By introducing the H2 gas, the evaporation of silver powder was enhanced. With increasing H2, raw powder was fully evaporated and prepared powder was evenly distributed with a mean size below 100 nm.

Microwave plasma synthesis of TiN and ZrN nanopowders

This work demonstrates that TiN and ZrN nanopowders can be prepared by microwave plasma synthesis method. The effects of flow rate of plasma forming gas, flow rate of carrier gas and feeding rate of precursor raw material to the average particle size were studied. The TiN and ZrN nanopowders were characterized by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD).

An Experimental Study of the Thermal Performance of a Screw Conveyor Dryer

ABSTRACT In the present study drying of fine crystalline solid was carried out in a non-insulated jacketed screw conveyor dryer SCD of 3 m length and 0.072 m screw diameter. It is nitrogen-swept to carry off the evaporated moisture. Dryer performance was evaluated in terms of the final moisture content, heat-transfer coefficient, thermal efficiency and power consumption. From the experimental results it was observed that drying under low pressure gives 92% moisture removal compared to 30–40% using low flow rates of nitrogen. The initial moisture content was in the range of 5 to 6%. Over the parameter range studied, the overall heat transfer coefficient was found to be in the range of 46–102 W/m2K. The average rise in the temperature of the product was 40 to 50°C. Thermal efficiency (based on sensible and latent heat) of the dryer obtained was found to be in the range of 25–62%, typical values obtained in falling rate drying period. Power consumption per metric ton of dried material was found to be a strong function of screw speed and material feed rate, material properties, and drive efficiency.

Induction plasma synthesis of fullerenes and nanotubes using carbon black–nickel particles

The existence of fullerenes (as allotropes of carbon) was established in the mid-1980s and during the last 15–18 years, systematic efforts have been devoted to improve the methods of their synthesis, including plasma-based system methods. The work presented here is focused on the investigation of fullerenes synthesis, using a radio frequency plasma reactor. The main objectives were to explore the use of induction plasma technology for the synthesis in-continuo of carbon fullerenes and to predict their formation conditions through conduct of theoretical studies. Thus, a thermodynamic study was carried out to predict the equilibrium composition of fullerenes produced at several combinations of operating conditions. Additionally, a statistical factorial design experiment, employing four factors at two levels, was also developed, in order to study the influence of the system’s operating parameters on the eventual C 60 fullerene yield. The results obtained showed that the reactor pressure, the electrical power and the raw material feed rates all have an important effect on the synthesis of fullerenes. The highest C 60 concentration in the products was found to be about 7.7 wt.%. Various other carbon nanostructures, such as nanotubes and nano-onions, were also successfully produced.

The measurement of plant residues distribution quality after harvest by conventional and axial combine harvesters

This paper concerns the evaluation of the husk and straw distribution quality measurement on different commonly used combine harvesters. The plant residues can significantly influence the next plant germination and growth, especially when they are unevenly placed on the field surface. The experiments were realised during the harvesting season in years 2001, 2002 and 2003. All machines were evaluated under normal operational conditions by winter wheat and oil rape harvest. For plant residues distribution quality evaluation the Christiansen’s coefficient was calculated. The most important outcome from the measurement is that the distribution pattern of husk and straw depends on instantaneous material feed rate through the harvester. The higher material feed rate the worse regularity of husk and straw distribution. Axial combine harvesters break up straw more intensively then tangential combine harvesters. Straw crushers on tangential combine harvesters are therefore more loaded and need more attention from the crushing and distribution quality point of view. On the contrary, on axial combine harvesters most material goes on cleaning sieves and more attention should be paid to this small particles distribution.

Fractionation of Alfalfa into Leaves and Stems using a Three Pass Rotary Drum Dryer

Fractionation/separation of chopped alfalfa into leaf and stem components was investigated using a small industrial three-pass rotary drum dryer. Both drying and fractionation of chopped alfalfa were successfully achieved in a single operational process. Generally, fractionation is carried out only as a separate process and, therefore, more costly overall. The success of fractionation was determined by the total amount of the desired component (leaf or stem) recovered, relative to the amount entering the process (i.e. separation efficiency) and by the purity (leaf or stem proportion) of the component in a product stream collected at the cyclone or drum exit. A series of experiments under different operating conditions were performed to establish the optimum process conditions leading to maximum separation efficiency and leaf purity. The operating variables used during experimentation were the outer drum end gate opening area, material feed rate, gas flow rate and gas temperatures at the drum inlet. The experimental results indicated that leaf purity decreased and separation efficiency increased with a decrease in dryer drum end gate opening area. A decrease in separation efficiency was observed with an increase in material feed rate. On the other hand, leaf purity increased and separation efficiency decreased with a decrease in gas flow rate. The decrease in separation efficiency was most significant at low gas flow rates. Separation efficiency decreased with a decrease in gas inlet temperature. Stem moisture content was observed to be consistently higher than the leaves. Lowering stem moisture levels to an acceptable level of 8% moisture content results in over drying of the leaves, leading to a loss in product quality. It was determined that the relative difference in moisture levels of stems and leaves at the drum and cyclone exit, respectively, can be averted by re-circulating in the order of 20% of the wet material (stems) from the drum exit back through the dryer inlet.

Continuous flow cracking of waste plastics

Experiments of waste polymers cracking in a continuous flow tube reactor were carried out. The main components of the reactor unit were a screw extruder as a waste plastics feeder and a tube cracking reactor equipped with an internal screw mixer. Cracking process was realized at the temperature range 420–480 °C and raw material feeding rate from 0.3 up to 2.4 kg/h. The principal process products, gaseous and liquid hydrocarbon fractions, are similar to the refinery cracking products. They are unstable due to the high olefins content (especially from polystyrene cracking) and their chemical composition and properties strongly depend on the applied feed composition, i.e. shares of polyethylene, polypropylene and polystyrene. The material balance experiments showed that the main products, liquid or solid materials in ambient temperature, contain typically 20–40% of gasoline fractions (range of boiling point 35–180 °C) and 60–80% of light gas oil fractions (initial boiling point>180 °C). The solid carbon residues are similar to coal cokes and contain even of 50% mineral components. Their calorific values attain 20 MJ/kg and they are solid fuels of quality similar to brown coals.

Microwave plasma synthesis of silver nanopowders

Silver nanopowder was synthesized by the microwave plasma synthesis method. The effect of feeding rate of precursor raw material to the average particle size and crystallinity were studied. The microwave plasma unit can be modified to prepare silver nanopowder with polymeric coating. The silver nanopowder was characterized by means of transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDAX) and X-ray diffraction (XRD).

Modelling Powder Concentration Distribution From a Coaxial Deposition Nozzle for Laser-Based Rapid Tooling

Direct laser deposition is a solid freeform fabrication process that is capable of producing fully dense components with full structural integrity and is greatly enhanced by the use of an omnidirectional coaxial powder nozzle to supply the build material. In order to optimize the technique, accurate control of the two critical operational parameters of material feed rate and incident laser power intensity is necessary. Both parameters are affected by the axial powder stream concentration between the nozzle and the deposition point. In this work, a mathematical model for the powder concentration distribution is developed and the results from it compared with an experimental investigation using optical and image analysis techniques. The two show good agreement. The application of the model to the evaluation of nozzle geometry and the calculation of laser beam attenuation are demonstrated.

Transformation of mineral and emission of particulate matters during co-combustion of coal with sewage sludge

Co-combustion of coal with sewage sludge was carried out in laboratory-scaled drop tube furnace to understand the interaction between different fuels. The combustion conditions were selected as follows: the raw material feeding rate was 0.2–0.3 g/min, temperature was 1200 °C, the atmosphere of 10% O 2 and N 2 being balance was used to guarantee an air ratio of 1.5, and the residence time varied from 0.6 to 2.4 s. The coal/sewage sludge is kept at 50:50 (wt% to wt%), four fuel pairs were selected with respect to the mineral association within individual fuel. The results showed the obvious interaction between coal and sewage sludge during their co-combustion. For the carbon conversion, the devolatilization of mixing fuel occurred quickly; the combustion of both char and evolved volatile progressed almost completely. As a result, the unburnt carbon was almost zero in the fly ash. In addition, the evolution of both mineral and PM varied with the association of minerals in raw fuels. For both coal and sewage sludge rich in included minerals, they combusted separately in the furnace, less interaction occurred accordingly. Conversely, for both them rich in excluded minerals, the minerals reacted with each other to form much agglomeration, and therefore, the particle size of the fly ash was increased, while the amount of PM was decreased, which changed as the coarse fly ash particles. Finally, for the case of coal rich in excluded mineral and sludge rich in included mineral, their co-combustion led to the interaction of their minerals. As a result, more the fine particles were formed, which in part changed into PM. For the vaporized trace elements, they were adsorbed by the melt CaPO 4/Al–Si in the ash and accordingly, their contents in the particulate matter were reduced whereas their particle size distribution shifted to the large value.

Optimization of Sweet Bread Dough Processing Conditions by Twin Screw Extrusion

Abstract Effects of material feed rate, water addition amount, screw speed and sets of kneading elements on sweet bread dough handling properties and bread qualities were studied by Response Surface Methodology in twin screw extrusion. Results showed that dough stickiness was significantly affected by water addition amount and screw speed (p < 0.001, R2 = 0.9227). Firmness of bread crumb and spread ratio, which is an index for bread appearance, were both significantly affected by water addition amount, screw speed, and sets of kneading elements (p < 0.001, R2 = 0.8940; p < 0.001, R2 = 0.8884). The optimal conditions for sweet bread dough processing are water addition amount ranging from 45 to 50 %, screw speed ranging from 180 to 280 min−1, with material feed rate and kneading element set fixed at 40 min−1 and ten, respectively.

Development and testing of two methods for the measurement of the mowing machine feed rate

Two methods were developed and tested for the measurement of the mowing machine material feed rate (based on the conditioner power input measured by a torque-meter, and/or on the material change in momentum measured by a curved impact plate). The measurements carried out in the year 2001 proved that a very good linear relationship existed between the conditioner power input, output frequency of the apparatus measuring the impact force by means of the impact plate, and the material feed rate through the mowing machine. The calculated R-Squared values were about 0.95. In the year 2002, the impacts of material and condition (parameters) changes on the mowing machine material feed rate measurement accuracy were measured under laboratory conditions. It was evident from the statistical evaluation that changing crop variety, crop maturity, and intensity of conditioning can have a statistically significant influence on the measurement based on the torque-meter. As concerns the impact plate measurement, it was found that it is not possible on the basis of our measurements to determine statistically the influence of the factors tested. 

Comparison of two possibilities for mowing machine material feed rate measurement under laboratory conditions

The impact of materials and conditions (parameters) changes on mowing machine material feed rate measurement accuracy were measured under laboratory conditions. The influence of crop variety, crop maturity and moisture, and intensity of conditioning were tested. The impact of the changing parameters in two measurement methods (based on torque-meter and/or on impact plate) was studied. Eight files of torque-meter and/or impact plate measurement were obtained during our experiments. Statistical analysis was used for data evaluation. Two-sample comparisons were used for torque-meter measurement. It is evident from that evaluation that changing crop variety, crop maturity and intensity of conditioning can have statistically significant influence on the measurement based on torque-meter. For impact plate measurement the analysis of variance was used. It was found out that it is not possible to statistically determine the influence of tested factors on our measurement. Considering these results the material feed rate measurement based on impact plate is better from practical point of view.

Laboratory Measurement of Mowing Machine Material Feed Rate

The main objective of this research was to evaluate two possibilities of material feed rate measurement of modern mowing machines equipped with conditioner. The machines are commonly used for harvest of grasses (Lolium multiflorum, Dactylus glomerata, Phleum pratense, etc.), clover (Trifolium pratense, etc.), alfalfa (Medicago sativa) etc. A mowing machine with finger conditioner was equipped with an electronic measuring unit for the purpose of our measurements. The mowing machine's conditioner shaft was supplied with strain gauges placed on a torque-meter and with a RPM optical sensor counter. Together with torque-meter the mowing machine was equipped with a curved impact plate mounted on the machine's material output. It was decided to arrange a laboratory measurement to obtain information about the dependence of conditioner power input and signals from the impact plate on material mass flow. A mixture of grass and alfalfa was used for our measurement. The measurements carried out proved that a very good linear relationship existed between the conditioner's power input, output frequency of the apparatus measuring impact force by means of the impact plate, and material feed rate through the mowing machine. The calculated coefficients of correlation were about 0.95. It is possible to differentiate a material feed rate difference of 0.5kg s−1 using both methods. This accuracy should be sufficient for practical utilisation such as creating yield maps.

Machining Quality and Cost: Estimation and Tradeoffs

Simultaneous improvement of machining cost, quality and environmental impact is sometimes possible, but after the Pareto optimal frontier has been reached, decisions must be made regarding unavoidable tradeoffs. This paper presents a method for formulating a mathematical model for first estimating quality, cost and cutting fluid wastewater treatment impacts of two machining operations (end milling and drilling), and then for tradeoff decision making. The milling quality estimation model is developed through virtual experimentation on a simulation model, while the drilling quality estimation model is developed through physical experimentation. Cost is estimated through an activity based costing approach. Cutting fluid wastewater treatment impacts (BOD and TSS) are estimated through stoichiometric analysis of cutting fluids. Input decision variables include material choice, design, manufacturing and limited lubrication parameters. The contribution of this paper is the integration of activity based cost estimation, machining quality estimation via statistical analysis of data from virtual and physical experiments, cutting fluid wastewater treatment impact estimation and formal decision theory. A case study of an automotive steering knuckle is presented, where decision variables include material choice (cast iron versus aluminum), feed rate, cutting speed and wet versus dry machining.

Preparation of Ultra-fine Aluminum Nitride in Thermal Plasma

Ultra-fine aluminum nitride has been synthesized by the evaporation of aluminum powder at atmospheric-pressure nitrogen plasma in a hot-wall reactor. The average size of aluminum nitride particle is 0.11 μm measured by scanning electric mirror (SEM), and the purity is at least over 90% evaluated by X-Ray diffraction (XRD). The conversion of Al powder to aluminum nitride is strongly depended on the injection of NH3. Typical experimental parameters such as the feed rate of raw material, the flow rate of ammonia and the position of injecting aluminum powder into the reactor are given.

Grinding of Hard Fine Materials by Jet Mill

The grinding rate characteristics of hard fine materials was investigated with a laboratory scale jet mill. The variations of product size distributions of synthetic diamond, alumina and quartz sand with the number of passes were described by using a grinding kinetics approach for various values of the grinding air pressure and the feeding rate. As a result, the grinding rate was found to decrease with increase in the hardness of comminuted materials from quartz to alumina and then to increase slightly for synthetic diamond due to its low impact strength. This trend is more pronounced for all materials with higher gas pressure and lower material feed rate. Thus, it is proved experimentally that the grinding characteristics of very hard materials even around 1, μm with the jet mill still fits the rate equation of comminution but the effect of operational conditions becomes low.