Pneumatic Spreader Research Articles

Improving the congruency of satellite-based fertilizer maps with field-operable units using pneumatic spreaders

The dramatically increasing nitrogen fertiliser prices and growing environmental awareness emphasise the need to optimise machine operability to avoid double overlapping of the target dose rate in different field units, including headlands and field bodies, to be more congruent with satellite-based nitrogen prescription maps. However, the map grids frequently do not correspond with farmers’ management practices, specifically machine operability. To this end, this study develops an algorithm that subdivides any given field into operable units by considering pneumatic spreaders based on the actual tramline on the field and placing the operable units along with this. The newly developed algorithm allows ex-ante specification of the required fertiliser amount. It shows how well such techniques can implement an optimised application map supported by the statistical information for each field unit. Uniform fertilizer application can further be compared with variable rate application (VRA) as well as machinery with and without section control, allowing the identification of areas with the greatest deviation and the excess amount of nitrogen applied. A more precise nitrogen application on both homogeneous or heterogeneous field units saves nitrogen and decreases the negative environmental impact.

Experiments and simulation of the spreading behavior of fibre bundle in pneumatic spreader

Fibre spreading before impregnation process has great importance for production of non-woven fabrics. Thousands of filaments can be transported and spread by airflow in a pneumatic chamber. To better understand the lateral-spreading mechanism of the system, the generation and evolution of lateral dragging forces applied on fibre bundle are demonstrated through experiments and simulations. with the CFD model of the spreader and discrete element method (DEM), the spreading behavior of the filaments in the bundle are simulated. By parametrically analyzing the characteristics of fractal airflows, the influence of design parameters on the fractal airflow is analyzed and optimized. The simulation results are in good agreement with the experimental data. The width of the bundle has been widened almost 10 times, which has improved by 100 % compared with traditional mechanical spread method.

Granular Fertilizer Spreader Swath Uniformity Achieved at Varying Target Application Rates

This study measured the within-swath uniformity of both spinner and pneumatic spreaders over a range of material application rates commonly associated with precision agriculture schemes (25 to 200 lb/acre). Although small pan sampling is not appropriate for spreader rate calibration, results suggested that five of the spreaders delivered rates ranging from 50 to 200 lb/acre with reasonable accuracy. Four of the five spreaders also appeared capable of delivering an even lower rate, 25 lb/acre. Within swath coefficients of variability (CV) values ranged from 16 to 30% for the most uniform of the spreaders tested, and from 45 to 122% for the least uniform. When different products were applied by multi-bin spreaders, substantial fluctuation in measured product ratios occurred for bulk bin products. For a single spreader evaluated with a micronutrient bin, micronutrient application rates and variability were relatively consistent regardless of the co-applied bulk bin product rate. The type of spreader (spinner or pneumatic) did not appear to determine the uniformity of application. Our data suggests a within-swath CV of 20 to 30% as a reasonable uniformity target for granular fertilizer spreaders under North Carolina commercial farm conditions.

Factors Affecting Strength of Road Base Stabilized with Cement Slurry or Dry Cement in Conjunction with Full-Depth Reclamation

Full-depth reclamation (FDR) in conjunction with cement stabilization is an established practice for the rehabilitation of flexible pavements. Conventionally, the FDR process involves applying dry cement powder with a pneumatic spreader, but this process can create undesirable fugitive cement dust. To solve this problem, cement slurry has been proposed because it can allow cement stabilization to be used in urban areas. This research sought to (a) identify construction-related factors that influence the strength of road base treated with cement slurry in conjunction with FDR and quantify the effects of those factors and (b) compare the strength of road base treated with cement slurry with that of road base treated with dry cement. Full-factorial laboratory experimentation on a road base sampled from an FDR project was conducted. The 7-day unconfined compressive strength was measured as the dependent variable. The independent variables included cement content; slurry water batching temperature; presence of a set-retarding, water-reducing admixture; cement slurry aging temperature; cement slurry aging time; cement–aggregate mixing time; and form of cement. The results suggested that the slurry water batching temperature, the haul time, the environmental temperature, and the presence of a set-retarding, water-reducing admixture would not significantly affect the strength of a cement-treated base (CTB) within the ranges of the factors investigated in this research. However, cement content and cement–aggregate mixing time were found to be positively correlated with CTB strength, regardless of the cement form. Additionally, the use of cement slurry was found to result in slightly lower strength values than the use of dry cement.

Analysis of winter wheat yield in the production system based on tramlines (technological tracks)

A comparison of the results related to the yield concerning the experiment settings within the three-year period without and with tramlines proves the hypothesis that the wheat yield increases by 20 or more percent on account of the application of tramlines. The average yield of 7.78 tha−1 achieved by the use of this technology is by 20.62 % higher compared to the yield of 6.45 tha−1 achieved using the conventional wheat growing method, which does not apply tramlines. Yield increase is due to timely and proper fertilization and crop protection, as well as the performance of full-range working operations. The transversal yield variability expressed as s variation coefficient for both settings is significantly lower compared to the variability of a centrifugal spreader, which is in broad use for fertilizing. It is necessary to apply pneumatic spreaders even in the cases when tramlines cannot be used. They distribute fertilizers evenly, and it is well known that this has a decisive influence on high and stable yield. Outstandingly high hectolitre masses and 1,000 grains masses with low variation coefficients showed no significant deviation for both settings. The analysis of the results showed a substantial effect of margin rows on the yield increase related to the setting with tramlines. The average yield was 9.69 tha−1 and it ranged from 8.39 to 12.02 tha−1 in different samples.

Numerical simulation and experimental investigation for design of a carbon fiber tow pneumatic spreading system

The work successfully designs a high efficient carbon fiber pneumatic spreading system. The internal flow field of the fiber pneumatic spreader was first simulated by solving Reynolds-averaged Naiver–Stokes equations, and the characteristics of the flow pattern in the spreader under various operation conditions were analyzed in terms of the mass flow rate and the velocity distributions. Comparisons of numerical results with measured velocity and pressure distributions were made to determine the accuracy of the employed method. A good agreement was found in both qualitative and quantitative analysis. A new variable, spreading evenness, was defined to specify the dispersing extent of fibers in a carbon fiber tow during the fiber pneumatic spreading process. By the spreading evenness, a quantitative comparison of a spread carbon fiber tow can be made and the optimum condition can be easily obtained at fiber spreading experiments. The dispersing mechanism of a carbon fiber tow was comprehensive by the computational modeling and the spreading experiment. The performance of the fiber tow pneumatic spreader system was better than prior studies, and the use of numerical analysis combined with the fiber spreading experiment was useful for the development of the fiber pneumatic spreading system.

Numerical and experimental study of internal flow field for a carbon fiber tow pneumatic spreader

In this study, a three-dimensional (3-D) mathematical model of a fiber pneumatic spreader was successfully developed in the physical phenomena of the internal flow field by a far-field treatment at boundary conditions. The 3-D numerical analysis was carried out on incompressible fluid flows in the pneumatic spreader by using finite volume method combined with the k-ɛ turbulence model which solves Reynolds-averaged Naiver-Stokes equations. Characteristics of the flow field in the spreader at different service conditions are investigated by velocity and pressure distributions. Comparisons of numerical results with measured velocity and pressure distributions were made to determine the accuracy of the employed method. A good agreement was found in both qualitative and quantitative analysis. Fibers were spread on 1:1-scale model of the pneumatic spreader at various fiber transporting rates and air flow rates. Photography techniques were simultaneously used to record the procedures of fibers spread. The carbon fiber tow was easily spread out at service conditions. The performance was better than prior studies in one-dimensional orifice formulation. The results revealed details of the fiber spreading processes. Agreement among those results validated the assumptions inherent to the computational calculation and gave confidence to more complex geometries as well as flow fields. In other words, the use of numerical analysis in the internal flow field was useful for the fiber pneumatic spreader design.

A Pneumatic Spreader for Applying Herbicide Granules and Herbicide-Fertilizer Mixtures to Field Plots

A small -plot, pneumatic applicator was developed to apply either granular herbicide formulations or liquid herbicides impregnated on commercial dry fertilizer to field research plots. Pre-weighed herbicide samples poured into a stainless steel, motor-driven belt, cone seeder are automatically sput into four subsamples in a four-outlet rota seed distributor run by a 12-volt electric motor, and delivered to four plastic venturi chambers. A gasoline engine-powered leaf blower forces air through a 10-cm diam polyvinylchloride (PVC) pipe to the input sides of the venturi chambers. The forced air stream carries the herbicide samples through 2.5-cm diam flexible plastic tubing to four deflector shields mounted 61 cm apart on a fiberglass boom. The applicator uniformly delivers granules up to 400 kg/ha in a 2.5-m wide swath.

Research on the Pneumatic Spreader Stoker : 3rd Report, on the Ignition of Carbon Globule in Uniform Stream of Air

Recently spreader stokers are used in many plants, and in the furnaces of these plants a part of the fuel burns in the state of suspension. In this paper, the ignition phenomena of the fuel located in the stream of the air are treated theoretically. On account of simplification of this problem, it was assumed that the gas flowing around the fuel was pure air and fuel was of carbon globules. The conditions for numerical calculations are as follows ; temperature of air stream=600∼1000°C velocity of air stream=0∼20 m/s radius of carbon globule=1∼15 mm termal-conductivity of carbon globule=0.22∼20 kcal/mh°C. From the results of these investigations, it has been concluded that (1) with the increment of the ignition temperature of carbon globule, the effect of temperature and velocity of air stream on the ignition time becomes remarkable, (2) the effect of thermal-conductivity of carbon globule on the ignition time is little.

Research on the Pneumatic Spreader Stoker : 4th Report, On the Combustion of a Carbon Globule in Uniform Stream of Air

In this paper, we theoretically treated the combustion phenomena of carbon globule in uniform air stream on the same assumptions as in 3rd report. The conditions for numerical calculations are as follows ; temperature of air stream=800∼1000°C velocity of air stream=5∼20 m/s radious of carbon sphere=2.5∼10 mm From the results of these investigations, it has been concluded that the effect of the temperature of air stream on both the combustion rate and the temperature of carbon globule is hardly conspicuous as compared with the other two factors.

Research on the Pneumatic Spreader Stoker (2nd Report)

Research on the Pneumatic Spreader Stoker (2nd Report)

Research on the Pneumatic Spreader Stoker (1st Report) : On the Acceleration of Particle in a Horizontal Pipe and its Flying Distance

Research on the Pneumatic Spreader Stoker (1st Report) : On the Acceleration of Particle in a Horizontal Pipe and its Flying Distance