Research On Key Techniques Of Microwave Drying

This paper mainly studied on microwave drying technology in the drying process, the drying chamber structure and key technical problems such as electromagnetic field distribution characteristics of microwave drying experiments are carried out using home-made microwave drying equipment research; Based on cavity theory is combined with maxwell’s equations, obtained the microwave coupling theory of rectangular resonator model of microwave cavity uniformity number calculation method, studied the theory of microwave drying chamber, drying chamber uniformity calculation; For the experiment and application of electromagnetic field simulation software HFSS drying chamber are analyzed in the simulation.During the microwave drying related experimental research dry molybdenum powder, five typical materials such as copper sulfate, big jujube water. In the experiment, compared the advantages and disadvantages of continuous heating and intermittent heating method; Microwave heating is analyzed three kinds of materials at all stages of energy utilization and the dehydration rate; Summarizes three kinds of material drying experimental data, corresponding to the power of microwave drying equipment drying moisture capacity. Also some experimental phenomena in the process of observation and analysis of the experiment, such as molybdenum powder microwave drying in the individual parts of the phenomenon of high temperature red, when the average temperature higher than120℃sulfide odor gas evolution. Copper Sulfate Pentahydrate in the microwave drying process, when the temperature is higher than45℃blue material began to become white. Jujube microwave drying experiment, when the160w microwave power continuous radiation jujube have jujube fragrance emitted more than three minutes, when the continuous radiation over a specific time after the phenomenon such as jujube can appear anxious burnt hard heart. Do the experiments of three kinds of material of microwave drying technology has carried on the preliminary discussion.Drying chamber in a selected center near the operating frequency range of how much is the measure of the possible model number dryer energy distribution uniformity of important reference standard. By applying the mode number calculation method to draw a scientific and reasonable mode of the highest number of cavity size, can also be calculated by fixed pattern number required by the size of the drying chamber, can also according to the formula to calculate the number to get a certain model for rectangular design size of the drying chamber.This article using Ansoft HFSS software related electromagnetic field simulation, is used to experiment simulation of microwave drying chamber as the main object, the experiment used drying chamber modeling1:1in the electromagnetic field simulation software, using the function of the software change the shape of a drying chamber model, explore the drying chamber geometry effect on the energy distribution of drying chamber; Change the quantity of the microwave radiation feed, analysis of different number of feed dry indoor the influence of the electric field distribution and the size of the field; Under the condition of same number feed, analysis about the different arrangement of the feed mouth dry indoor electric field distribution and the influence of the field strength, simulating a certain size of drying chamber feed way of the optimal configuration. The drying experiments and calculation and electromagnetic field simulation study will be beneficial to the reality of microwave drying technology and improvement of feed drying chamber design and manufacturing.