Design Of Distribution Bench For Precision Measuring Spray Nozzle Integrative Performance And On Fan Spray Nozzle

Chemic pesticide product has been a great threat to people's health and environment balance because of superfluous application. The antiquated instruments and techniques are the main reasons for that. The hydraulic pressure atomization is the main means of application of pesticide product at present. Spray nozzle is the key part of the crop protection mechanism in the process of atomization, whose performance decides the pesticide product efficiency. Compared with the advanced countries, the variety of spray nozzle is deficient and the quality is inferior in China. The scientific research investment is not enough, and the base of scientific research is very unsubstantial. These are the main reasons why the spray nozzle was not developed enough. Until now the study of spray nozzle performance is far from enough, because the scientific research conditions of crop protection in China lag behind, and the scientific research apparatus are in universal need. Therefore, the design of distribution bench for precise measuring spray nozzle integrative performance is essential to the further study of spray nozzle integrative performance.The main content includes:(1) Design of distribution bench for precise measuring spray nozzle integrative performanceIn order to study integrative performance of spray nozzle, a distribution bench for precise measuring spray nozzle integrative performance is to be built. The spray total flux, spray distribution, spray angle, hydraulic pressure and environment temperature can be accurately measured on the distribution bench. The flux of spray nozzle is one of the key performance parameters of spray nozzle; it is measured by accurate electromagnetism flow meter. The spray distribution indicates the spray distribution uniformity degree as one of spray performance parameters, and it is measured by sixty subminiature weight sensors. The atomization liquid collected by collecting spraying slot is measured by these sensors. In order to prevent the spraying droplet splashing from the slot, a labyrinth structure is introduced. The information from all weight sensors is collected by acquisition card. A network is built to collect information by multi-acquisition cards. The spray angle reflects the spraying extent range and it is measured by image processing. The hydraulic pressure is adjusted by computer with two means. One means is realized by overfall value and the other is realized by changing pump-motor rotating speed. The overfall value is controlled by subminiature motor with PID control arithmetic. The hydraulic pump motor is driven by transducer. The computer controls the motor rotate speed with fuzzy control arithmetic by communication. The situation of spray actual working in the field can be simulated on the bench. The spray nozzle movement is driven by cylinder with the help of computer. The closed loop control mode enhances the reliability. The control operation can be realized by graphics mode expediently.(2) Design of special numeric control system for testing spray nozzle integrative performanceA special numeric control system for spray nozzle integrative performance is designed in order to enhance capability, reliability and expansibility. With the help of numeric control system, the upper-computer realizes the data acquisition and controlling functions. The special numeric control system can finish all the functions by itself too. In the design of numeric control system, the 16-bit MSP430F149 is selected as its powerful functions. In the design of extended interface circuit, the 74LVC4245 and phototube are both used. And they enhance the anti-jamming capability effectively. Multi-communication interfaces are designed in the serial communication interface circuit. Every communication interface can be enabled by chip-selection signal. LCD OCMJ4*8C is selected as display of the numeric control system and is controlled by serial interface. The serial interface mode and phototube used in the serial interface enhances the anti-jamming capability.(3) Study of relation between fan spray nozzle performance and configuration parametersThe fan spray nozzle has been widely used in the crop protection field. The configuration parameters include spray nozzle inner diameter, relative kerfs depth and V-shaped slot angle. The spray nozzle performance parameters include flux, spray angle and spray distribution uniformity. The effect of the performance by configuration parameters is studied adequately.â‘ Relation between flux and configuration parametersThe dosage of pesticide is determined by spray flux. The spray nozzle flux is studied by theory calculation and experiment firstly. The experiment conclusion indicates the spray flux increases with the inner diameter increasing. Theoretic calculation result is: the export area changing with inner diameter is primary case of flux changing. Study relation between spray nozzle flux and relative kerf depth. The experiment conclusion indicates the spray nozzle flux increases with the relative depth increasing at the beginning. However, with the relative kerf depth increasing unceasingly, the spray nozzle flux decreases on the contrary. Theoretical calculation indicates that the export area changing with the relative kerf depth is the primary case of flux changing.Study relation between flux and V-shaped slot angle. The experiment indicates spray nozzle flux changed with V-shaped slot angle changing. The theory calculation indicates the export area changing with V-shaped slot angle is the primary case of flux changing with V-shaped slot angle.â‘¡Study relation between spray angle and spray nozzle configuration parameters The spray nozzle angle determines the spray distribution extent breadthwise. Theexperiment indicates that spray angle increases with the relative depth increasing firstly, with the relative depth increasing unceasingly, spray angle decreases on the contrary. Spray angle decreases with V-shaped slot increasing. Spray angle increases with inner diameter increasing, the increasing trend changes slowly gradually.â‘¢Study relation between spray distribution variability coefficient and configuration parametersSpray distribution variability coefficient indicates the spray distribution uniformity degree. The experiment conclusion indicates that there is no obvious correlative relation among V-shaped slot angle, inner diameter and relative kerf depth and spray distribution variability coefficient.â‘£Analyse about integrated factorsThe relation between spray nozzle performance and all structure parameters are studied by BP nerve network. Nerve network is built about relation among spray angle, spray inner diameter, relative kerf depth and flux, V-shaped slot angle. The conclusion is: the forecast value and the actual value are very coincident. BP nerve network can help us forecast the flux and spray angle based on the spray nozzle parameters.(4) Study spray nozzle utilizing performanceThe influences on hydraulic pressure to the spray nozzle flux, spray angle and spray distribution variation coefficient are studied systematically. The influences on spray nozzle height to the spray distribution, hydraulic pressure and height to the spray distribution under condition of multi-spray nozzle are studied, too. In addition, the quality on spray nozzle and different material spray nozzle longevity are investigated. â‘ Influences on hydraulic pressure to spray nozzle flux, spray angle and spray distributionThe spray nozzle flux increases with the increasing of hydraulic pressure. The sensitivity of the flux to pressure is different appreciably for different spray nozzle. The spray angle increases with hydraulic pressure increasing and the increase was less. It indicates that there is no obvious relativity between pressure and spray distribution.â‘¡Influence of spray nozzle height on spray distributionWith the spray nozzle' height increasing, the spraying range is extended in finite range, the average value decreases gradually. In the same conditions, there is a best height where the spray distribution is even and the spray distribution variation coefficient is least too.â‘¢Study utilizing performance of multi-spray nozzlesThe spray distribution is not symmetrical when height and interval between spray nozzles is not appropriate. The experimental conclusions indicate that the spray distribution variation coefficient changes with the height changing. There is a best height where the spray distribution variation coefficient is smallest and the spray distribution is best symmetrical. The optimal height position is not the same at different intervals or different pressure in a general.â‘£Experiments about other performances of spray nozzleThe performances were studied in the experiments about spray nozzle TEEJET SS800 and LUMARK 02F110. The conclusions indicate that the flux, the spray angle and the spray distribution of the same model spray nozzle are very accordant. The spray nozzle longevity of different materials is different. Experiments indicate that the longevity of the brass spray nozzle is the shortest, while the longevity of the corundum spray nozzle is the longest.