Design And Expriment Of The Gas Mixture Proportion System Dying Out Pests

It is important that warehousepests are killed effectively before storaging seed in warehouse.It can affect the health of workers that chemicals are used to kill pests until now.The Gas Mixture Proportion Systemadjusts the gas densityto die out pestsin warehouse by mixing gas according to the setting proportion. It is designed of The Gas Mixture Proportion System on the basis of the mixed gas to kill pests in this passage. Mathematical modeling methods and experimental research are used to study gas passage, control circuit of The Gas Mixture Proportion System and verify effect of the mixed gas to kill pests. Main contents in this passage are studied as follows:1)Method of Mass Flow is used on the basis of methods of comparing several gases mixing.controller mathematical modeling of gas valve and Mass Flow controller are set in this system.Relevant factors of The Gas Mixture Proportion System is analyzed theoretically through the gas valve and the Mass Flow controller model.Valve is analysis to understand the gas Mass-Flow qm with the pressure P1,P0 relationship between the pressure P1, P0 and mass flow qm a certain proportion;Characteristic of Mass-Flow Controller is analysis tostudy the Mass-Flow relationship, the accuracy depends only on the design parameters of the mass flow controller itself.it is nothing to affect with Mass-Flow of physical parameters.2)Gas passage and control circuit of The Gas Mixture Proportion System are designed according to the requirements of the The Gas Mixture Proportion System. Gas passage achieves function of gas mixing. The control circuit includes the power circuit,linear regulator circuit, the signal amplifier circuit and Mass Flow controller circuit etc.,Building a hardware platform on the basis of the gas passage and control circuit.3)The accuracy of The Gas Mixture Proportion System is verified on the hardware platform. CO2:O2density from 15%:2% to 50%:30% by setting different gas density.Comparing to the signal of the gas sensor feedback and the concentration of the detected gas. Accuracy of The Gas Mixture Proportion System is able to 95%.The results show that he Gas Mixture Proportion System can achieve the design requirements under laboratory conditions.4)The seed germination proportion is verified on the basis of the hardware platform. CO2 density and O2 density are set 45%?30%?15% and 8%?5%?2%. Two kinds of pests mortality reached 100% in 16? after 6 days by setting CO2:O2density 45:8?30:5and 15:2.In addition, two kinds of pests mortality reached 100% when CO2:O2density is 30:5 in 6? after 6 days. Meanwhile, they are no different between storaging rice seeds' germination rate s in atmosphere experimental and storaging in the air after 9 day. Therefore,the Mixed gas has no significant effect on the germination rate, under short-term atmosphere environment.