In-line Injection System Research Articles

A Turbidity Module to Measure Spray Mixture Concentration for Premixing In-Line Injection System

Highlights A turbidity sensor module was investigated to monitor concentrations of pesticide mixtures in real time. A flow-through measurement platform was built to calibrate the turbidity sensor and determine its accuracy. Optimal location of the turbidity sensor was determined for monitoring in-line mixture concentrations. Spray mixture uniformity reached acceptable level for the premixing in-line injection system. Abstract. Monitoring mixture concentrations for precision pesticide spray systems in real time can assure the desired amount of chemicals distributed uniformly to target areas. An in-line turbidity sensor module was investigated to monitor concentrations of spray mixtures produced with a premixing in-line injection system developed for precision variable-rate orchard sprayers. The turbidity sensor was calibrated with simulated pesticides at concentrations ranging from 0% to 30.0%. A cubic polynomial regression model was established for the relationship between sensor output voltages and mixture concentrations. Sensors were mounted at three in-line locations to detect the mixture uniformity differences in the premixing in-line injection system. The module was found to have adequate precision and accuracy to measure concentrations of spray mixtures with simulated pesticides. Relative errors of the sensor were less than 4.70% and the sensor accuracy did not vary with mixture flow rates. Mounting the turbidity sensor downstream of the buffer tank in the premixing in-line injection system would be the optimal location to monitor spray mixture uniformity for variable-rate spray applications. At this location, the relative errors of measured mixture concentrations were between 0.12% and 3.70% which agreed with previous manual measurements. Therefore, there would be a great potential to integrate the in-line turbidity sensor into the variable-rate and even conventional constant-rate sprayers to achieve uniform spray applications in the target field. Keywords: Agitation, Mixture uniformity, Pesticide concentration, Sensor calibration, Variable-rate sprayer.

Chemical Concentration and Spatial Uniformity of a Premixing In-Line Injection System Attached to a Variable-Rate Orchard Sprayer

HighlightsA newly developed premixing in-line injection system attached to a variable-rate orchard sprayer was evaluated.Tests were conducted to verify the in-line injection system performance using a vertical spray patternator.Concentration accuracy and spatial distribution uniformity were determined with a fluorescent tracer.Uniform spray mixtures were obtained for different spray viscosities and duty cycle combinations.Abstract. Pesticide spray application efficiency is highly dependent on the chemical concentration accuracy and spatial distribution uniformity. In this study, the performance of a newly developed premixing in-line injection system was evaluated when it was attached to a laser-guided, pulse width modulated (PWM), variable-rate orchard sprayer. The chemical concentration accuracy was determined with respect to spray deposition with a fluorescent tracer, and the spatial distribution uniformity was determined with spray deposits at different heights on a vertical spray patternator. Outdoor tests were conducted with 27 combinations of target chemical concentration (1.0%, 1.5%, and 2.0%), viscosity of the simulated pesticide (1.0, 12.0, and 24.0 mPa·s), and various spray outputs manipulated with PWM duty cycles. For each injection loop, the amounts of the chemical concentrate and water discharged into the mixing line were measured separately in response to preset target concentrations. The results showed that the measured concentrations were consistent across the patternator heights, spray viscosities, and duty cycle combinations. For all treatments, the mean absolute percentage error (MAPE) of the measured concentration was 6.96%, indicating that the concentration accuracy of the system was acceptable. The mean coefficient of variation was 3.35%, indicating that the spatial distribution uniformity of the system was in the desirable range. In addition, there was little variation in chemical concentration for spray mixtures collected at different heights on the patternator. Thus, the premixing in-line injection system could adequately dispense chemical concentrate and water to produce accurate concentrations and uniform spray mixtures for variable-rate nozzles to discharge to targets. Keywords: Environment protection, Precision pesticide application, Laser-guided sprayer, Tank mixture disposal, Specialty crop.

Assessment of chemical concentration accuracy and mixture uniformity of premixing in-line injection system

A premixing in-line injection system was developed and attached as a retrofit to a laser-guided variable-rate orchard sprayer. Chemical concentration accuracy and spray mixture uniformity produced from the premixing system was investigated with various viscosities of simulated pesticides and duty cycles of pulse-width-modulated (PWM) nozzles at different positions on the sprayer. The chemical concentration accuracy was accessed by calculating the relative error (RE) between measured and target concentrations, and mixture uniformity was evaluated by the coefficient of variation (CV) of the mixture concentration. Test results showed that the measured concentration was consistent across different nozzle positions, and RE and CV were observed within desirable ranges (<5.0%) for all nozzle positions and target concentrations. The average measured concentration slightly decreased as the viscosity of simulated pesticides increased. This phenomenon was more obvious under higher target concentrations. In addition, effects of PWM duty cycle combinations on the chemical concentration accuracy and mixture uniformity varied with number of active nozzles. It was found that RE and CV were larger than the desirable level (greater than5.0%) but were lower than the acceptable level (<10.0%) under conditions that nozzles were partly activated. For other treatments which all nozzles were activated, RE and CV were under the desirable level (<5.0%) for all target concentrations and nozzle positions. Laboratory tests demonstrated that the premixing in-line injection system was able to adequately mix the simulated pesticides with water, and could provide accurate and consistent uniformity of spray mixtures for the variable-rate spray nozzles to discharge different viscosities of simulated pesticides at different duty cycle combinations.

Hardware and Software Design for Premixing In-Line Injection System Attached to Variable-Rate Orchard Sprayer

.HighlightsA premixing in-line injection system was designed as a retrofit attachment to a laser-guided variable-rate orchard sprayer.A graphical user interface with touchscreen functions was incorporated into the system to facilitate field applications.Preliminary tests demonstrated that simulated pesticide and water could be accurately dispensed and discharged separately into the injection line and mixed well in the buffer tank.This premixing in-line injection system has great potential to further reduce pesticide waste and improve environmental stewardship for conventional and precision variable-rate sprayers.Abstract To eliminate the problems associated with leftover tank mixture in pesticide applications, a premixing in-line injection system was designed as an attachment to a laser-guided variable-rate orchard sprayer. The primary components of the system consisted of a chemical metering pump, a water pump, a two-stage static mixer, a premixing tank, a buffer tank, an electric shut-off valve, a chemical container, electronic control boards, a graphical user interface, and an embedded computer with a touch screen. Liquid level sensors were mounted in all tanks and the chemical container to control the fluid discharge and prevent overflows. The graphical user interface on the touch screen was designed for operators to communicate with the system and monitor the system status. During spray applications, the system performed with automatic loops in dispensing, mixing, and transferring the desired amounts of water and chemical concentrates to maintain the spray mixture at a constant concentration for use with variable-rate nozzles. The system was rinsed automatically when the spray application task was completed. Test results showed that simulated pesticide and water could be accurately delivered into the injection line and could be mixed well in the buffer tank before the spray mixture was discharged to the nozzles. The premixing in-line injection system is a potential technique to further reduce pesticide waste and improve environmental stewardship for both conventional and precision variable-rate orchard sprayers. Keywords: Automation, Environmental protection, Intelligent sprayer, Pesticide spray application, Precision agriculture, Tank mixture leftover.

Exploration of the problems and solutions related to reference introduction prior to calibration of thermal desorber-gas chromatography.

Reference introduction in thermal desorption with gas chromatography is a critical aspect. It is mostly performed by offline liquid calibration using a micro syringe to inject a liquid standard solution on the sorbent in the thermal desorption tube. This is based on the assumptions that the adsorption-desorption process is quantitative and that no sample is lost in manipulating the tube. However, for analytical procedures involving thermal extraction of solid matrices, the adsorption-desorption processes for sample and reference differ and the assumptions are not always fulfilled. This is explored in this work. First, issues related to the online liquid calibration were investigated. With tubes containing only quartz filters, a relative loss of over 80% was noticed for some solvents due to tube manipulation processes. Enclosing a bed of mesoporous silica as sorbent limited the losses to about 25% when samples were immediately analysed, and even better results were obtained when tubes were stored for several hours so that proper adsorption could take place. An additional sweep gas during loading boosted the transfer of analytes with recoveries above 95%. Next, an inline injection system was installed on the thermal desorber instrument. This sorbent free, independent calibration tool avoids the drawbacks of other approaches.

Improved premixing in-line injection system for variable-rate orchard sprayers with Arduino platform

To reduce the tank mixture leftover problem associated with variable-rate orchard sprayers, an experimental automatic premixing in-line injection system was developed with Arduino platform. This system primarily consisted of a precision fluid metering pump, a water pump, a static mixer, a premixing tank and a buffer tank. The required amounts of water and chemical concentrates were accurately pumped into the premixing tank through a static mixer. The mixture was then transferred into a buffer tank for additional mixing process and for the spray pump to discharge to variable flow-rate nozzles. When the buffer tank neared empty, this process was repeated automatically to maintain the same chemical ratio for all nozzles regardless of their spray output differences and variations. Accuracy of the metering pump was verified with simulated pesticide concentrates (tap water, turpentine oil, prime oil, and four different viscous sucrose solutions) at viscosities between 0.9 and 32.0 mPa·s. With addition of a fluorescent tracer, the sucrose solutions were also used to evaluate the uniformity of spray mixtures discharged from the premixing in-line injection system. Test results demonstrated that the fluid metering pump could accurately dispense desired volume (10–300 mL) of simulated pesticides at different pump rotational speeds with relative errors between measured and desired volumes below 5%. The uniformity of spray mixtures at different chemical-to-water ratios (0.1%–2.0%) was consistent, and the highest relative error and coefficient of variation were 7.6% and 4.5%, respectively. The experimental premixing in-line injection system was proven to have stable and accurate performance, and thus would have great potentials to improve spray application efficiency with minimized tank mixture leftovers for future variable-rate sprayers.

One-dimensional modeling and simulation of injection processes of bioethanol-biodiesel and bioethanol-diesel fuel blends

This paper presents the development of a complete simulation model for a mechanical in-line injection system feed with diesel, biodiesel, bioethanol fuel blends. The mathematical model is built by using the AVL Boost™ Hydsim software, while the required input data is carefully derived by making use of existing data as well as formulas and numerical procedures described in this work. This setup enables relatively efficient formulation and set-up of the mathematical model as well as consistent and reasonably accurate derivation of input data.The derived model is used to simulate the injection processes of various bioethanol-biodiesel and bioethanol-diesel fuel blends. The simulation results are compared to experimental data obtained on a Friedman-Maier type 12H100_h test bed at ambient temperature and several operating regimes. The results show that the compared injection pressure and needle lift histories are generally in a good agreement with the experimental ones. Consequently, the simulation model presented is fast and accurate enough to be engaged in various numerical procedures, ranging from investigations of influences of bioethanol addition to injection system optimization.

Embedded Computer-Controlled Premixing Inline Injection System for Air-Assisted Variable-Rate Sprayers

Improvements to reduce chemical waste and environmental pollution for variable-rate sprayers used in orchards and ornamental nurseries require inline injection techniques. A microprocessor controlled premixing inline injection system implementing a ceramic piston chemical metering pump and two small transition tanks was developed for air-assisted variable-rate sprayers. Unlike conventional direct inline injection systems that inject chemical concentrates into the delivery lines, this system first dispensed specific amounts of water and chemical concentrates into an injection chamber and then agitated the mixture in a transition (or premixing) tank. The mixture was then transferred into a second transition (or buffer) tank for discharge from the spray pump. This process was repeated when the buffer tank neared empty. The mixture in the buffer tank was maintained at a constant concentration that allowed the sprayer to discharge a wide dynamic range of variable-rate outputs with a consistent concentration for every nozzle. A touch screen monitor with an embedded computer allowed operators to interface with the injection system. The metering pump accuracy was verified with three simulated pesticides (water, prime oil, and milk). Mixture uniformity consistency was tested with six different viscous simulated pesticides (sucrose solutions) at viscosities ranging from 0.9 to 31.3 mPa-s. Test results confirmed that the metering pump accurately dispensed the simulated pesticides at different pump speeds, and the premixing inline injection system provided consistent concentrations of spray mixtures at the spray pump outlet. The new system avoided lag time, inconsistent spray mixture concentrations and inaccurate metering of chemical concentrates at low flow rates associated with conventional direct inline injection systems, and can further improve spray application efficiencies for variable-rate precision sprayers.

Controlling floc sizes in a pipe between pump and membrane inlet

Cake resistance is influenced by floc size deposited on membrane surface. Enlarging floc size can reduce cake resistance. The small particles are enlarged by coagulation and flocculation processes in conventional mixing tank at membrane filtration system. Fully-grown flocs for reducing the cake resistance, however, are ruptured while passing through a pump. In light of this fact, this study aims to experimentally look at the reaggregation phenomenon through control of G-values in pipe from pump to inlet of membrane. In addition, reaggregation phenomenon of the mixing system is compared with first-aggregation in-line injection system in which coagulant is injected just before a pump. These results suggest that first-aggregation of in-line injection system is better than reaggregation of mixing system for G-value above 3100 s − 1 . G-values in pipe of real world membrane filtration system are usually much larger than 3100 s − 1 . Due to reason, in-line injection system is expected to perform better than mixing tank as proved in this study.

Development of dimethyl ether engines for light-duty trucks using a large exhaust gas recirculation system

A light-duty truck diesel engine fuelled with dimethyl ether (DME) using a jerk-type in-line DME injection system, which meets the Japan 2009 Emission Regulation, was developed. It includes lower exhaust emission technology such as a large exhaust gas recirculation system with air-throttled and inter-cooled turbocharging. The National Traffic Safety Office, Environment Laboratory, and Bosch Corporation have demonstrated low-emission engines which reduce NO x emission levels to about 50 per cent of the 2009 emissions regulation without an NO x reduction catalyst system.

Inline Injection Microdevice for Attomole-Scale Sanger DNA Sequencing

A new affinity-capture-based inline purification, concentration, and injection method is developed for microchip capillary electrophoresis (CE) and used to perform efficient attomole-scale Sanger DNA sequencing separations. The microdevice comprises three axial domains for nanoliter-scale sequencing sample containment, sample plug formation, and high-resolution capillary gel electrophoresis. Purified and concentrated inline sample plugs are formed by electrophoretically driving Sanger sequencing extension fragments into an affinity-capture polymer network positioned within a CE separation channel. Extension fragments selectively hybridize and concentrate at the polymer interface while residual primer, nucleotides, and salts electrophorese out of the system. The plug is thermally released and injected into the CE channel by direct application of the separation voltage. To evaluate this system, 30 nL of sequencing sample prepared from 100 amol (60 million molecules) of human mitochondrial hypervariable region II amplicon was introduced into the microchip, purified, concentrated, and injected, generating a read length of 365 bases with 99% accuracy. This efficient inline injection system obviates the need for the excess sample that is required by cross-injection techniques, thereby enabling Sanger sequencing and other high-performance genetic analysis using DNA quantities approaching theoretical detection limits.

Implicit Numerical Model of a High-Pressure Injection System

An implicit finite-difference numerical method has been developed and applied to the simulation of unsteady flow phenomena in a high-pressure injection system. A first-order one-step BSBT (backward space, backward time) scheme was used to obtain the difference analogue of the one-dimensional, elemental-volume averaged, partial differential equations governing the pressure-pipe flow. Second and higher-order implicit difference representations were employed for the ordinary differential equations simulating the pump and injector dynamics. The resultant nonlinear algebraic equations were solved by the Newton-Raphson method and a fast modified version of the Gaussian elimination procedure was used to solve the linearized equations. This was an extension of the Thomas solver to a multidiagonal system of algebraic equations. A compact, efficient and stable numerical algorithm was so obtained. The mathematical model takes into account the compressibility of the liquid fuel, the boundary shear, and also includes the simulation of possible cavitation occurrence at one or multiple locations in the injection system. No artificial viscosity has to be added to the solution in the vicinity of discontinuities induced by cavitation in the flow properties. The cavitation simulation is based on a simple mixture model of transient two-phase flow in pipes and can incorporate the effects of gaseous cavitation occurrence. Experimental values of the flow coefficients were used for the pump and injector and, for the latter, the dependence of the discharge coefficients on the needle lift and injection pressure was also taken into account. The model was tested and validated by comparing the numerical results with those of experiments carried out at the Fiat Research Center on a diesel-engine inline injection system, with a jerk-pump and an orifice type nozzle-injector.