Thermophysical properties and porous properties of Soybean under microwave drying mechanical equipment

Abstract: The temperature and quality changes of Soybean samples during microwave drying were measured in real time by using microwave drying machine test system. The variations of physical properties such as density, thermal conductivity, specific heat and thermal diffusivity of samples with different moisture content during drying were analyzed. From the point of view of porous media, the variations of pore properties such as porosity, fractal dimension, pore diameter and specific surface area in different drying nodes (100%, 85%, 70%, 55%, 40%) were studied. Law. By changing the microwave heating power, the influence of microwave power on the heat and mass transfer of samples is analyzed. The results showed that during the microwave drying process, a dense membrane was formed in the cortex cells of soybean, which hindered the water migration. When the moisture content was reduced to 30%, the coke appeared inside the sample, and then the cells in the center collapsed completely. But the density of the whole drying process is not large, and the reduction is about 5 kg /m3. The thermal conductivity increases first and then decreases, reaching a maximum when the moisture content is 60%, and the internal temperature tends to be more uniform with the decrease of the moisture content. With the drying process, porosity and pore fractal dimension increase, and pores become more and more complex. The change of temperature in drying process has obvious phase, and the direction of heat transfer and moisture transfer is consistent. In the early stage of drying, the higher the microwave power (0.6 kW, 0.8 kW, 1.0 kW), the faster the sample temperature rises to 100 C. At this time, the internal temperature is higher than the surface temperature, while the internal and external temperature is basically constant in the late stage of drying, but the size relationship between the two is more complex than the previous stage. Key words: soybean; microwave drying; thermophysical properties; porous medium characteristics; temperature distribution
. 

评论

发表评论

此博客中的热门博文

Application of Camellia Seed Oil in Cosmetics Industry

图片
Before the advent of modern cosmetics, camellia seed oil was used as a traditional skin care hair care product in East Asia to improve the moisturization, smoothness and elasticity of skin and hair. Camellia saponin contained in camellia seed oil is a non-toxic surfactant with antioxidant activity and can be applied to advanced washing products. Compared with traditional surfactants, tea saponin has the advantages of being degradable, non-polluting and non-toxic, and is a natural active agent. Camellia seed oil can also be used to make cleansing oil with a very mild effect. Microwave drying machine Cosmetic grade camellia seed oil is mainly produced by low temperature and high pressure process. It is often used as a high-end cosmetic raw material or as a massage base oil, and is widely welcomed in domestic and foreign markets. Application of Camellia Seed Oil in Cosmetics Industry 
阅读全文

Research on Hydraulic Pump Control Technology

图片
1 blade control technology The high-pressure energy-saving hydraulic vane pump controls the vane through the electric signal and the pilot hydraulic oil, and uses the solenoid valve to control the pilot oil to pass through the rear distribution disc, leads to the outside of the propeller shaft, and finally flows into the vane pump rotor, the pump shaft, and the vane locking mechanism.  hydraulic vane pump   The pilot hydraulic oil acts on the slide valve to press a small steel ball into the concave surface of the blade. The blade is completely locked in the blade groove of the rotor, and the sealing volume cannot be formed between the blade, the stator, the rotor and the oil distribution plate, and the blade card The pump is idling, thus stopping the vane pump oil supply cycle, reducing the drive or engine output power, and saving energy. The high pressure energy-saving vane pump is stuck in the rotor when the system does not require flow and pressure. When ...
阅读全文

Microwave vacuum drying of banana slices

图片
The microwave vacuum drying equipment technology was used to develop new banana drying products, and the optimum microwave vacuum drying technology for banana slices was obtained. microwave vacuum drying   The effects of vacuum, microwave intensity and slice thickness on color difference, brittleness, swelling rate and sensory quality of banana slices were studied by three factors and three levels L9 (34) orthogonal design. The technological parameters of microwave vacuum drying of banana slices were optimized by comprehensive optimization method. The quality of dried banana slices obtained by different microwave vacuum drying process parameters is obviously different. The optimum point of microwave vacuum drying process is determined as follows: vacuum degree - 80 kPa, microwave intensity 14 W/g, slice thickness 12 mm. The quality of dried banana slices obtained under this process condition is better than that of microwave drying. And vacuum frying. It is fea...
阅读全文