Papers by Keyword: Vacuum Degree

Abstract: In order to ensure the medicinal efficacy and improve the production efficiency, design and production of a kind of microwave vacuum drying medicine extract new technical equipment. Through analyzing the principle of material characteristics of traditional Chinese medicine extract, drying, microwave vacuum drying, Design of microwave vacuum drying chamber, cylinder body, a door body, a material system. Based on the overall scheme, the main structure parameters were calculated, and the production of a set of test equipment, the dehydration rate test. The new process equipment efficiency, reduces the cost, the volume is greatly reduced, keep the efficacy, and has the functions of sterilization, especially suitable for the production of proprietary Chinese medicines industry.

Abstract: In this paper, mathematical model for heat transfer in thermal barrier is established based on the experiment which tested apparent heat conductivity of heat insulation oil pipes. Vacuum degree influence on performance of vacuum heat insulation oil pipe is analyzed by contrasting heat insulation oil pipes in different grades. The main conclusions are as follow. When internal pressure in the thermal barrier is between 0~20Pa or greater than 40Pa, the apparent heat conductivity increases with the pressure. And when internal pressure in the thermal barrier is between 20~40Pa, the apparent heat conductivity decreases with the pressure in volatility. When internal pressure in the thermal barrier is between 30~40Pa, the apparent heat conductivity of heat insulation oil pipe is lesser.

Abstract: During vacuum counter-pressure casting, the vacuumization is an important stage for thin-wall and complicated aluminum alloy castings. Through testing and an analyzing numbers of pinhole and pinhole grade of aluminum alloy samples under different vacuum degree, the effect of vacuum degree on pinhole of vacuum counter- pressure casting molten aluminum alloy is studied. The results indicate vacuum degree has greater effect on pinhole of molten aluminum alloy in vacuumizing process. The smaller vacuum degree is, the more numbers of pinhole of the samples are, and the higher pinhole grade of the samples is. Therefore, when vacuum degree is small, pinhole of molten aluminum alloy appears easily. So the vacuum degree doesn’t choose too small, but for thin-wall and complicated aluminum alloy castings, the vacuum degree doesn’t choose too big either. Appropriate vacuum degree is from 20 KPa to 40 KPa.

Abstract: Open-cell rigid polyurethane foam was taken as core material of the vacuum insulated panel, and the effects of open-cell ratio, density, cell-diameter and intensity on adiabatic performance of the vacuum insulated panel were simply discussed. The effect of vacuum degree on it is also discussed. The pre-treated craft of vacuum insulated panel manufacture is introduced too. If the open-cell rigid polyurethane foam was taken as the core-material and pretreated craft was carried, the vacuum insulated panel’s thermal conductivity can be less than 10mW/(m•K).

Abstract: There is much technical information of the engine running in vacuum △P in engine air intake system. According of the engine intake system analysis of the formation mechanism of vacuum △P, three-gradient analysis model is established. Then put forward the principle of quantitative diagnosis technology used the △P in automobile fault. Establish the concepts, such as "illegally gas", "quantitative diagnosis" in engine air intake system. Try to build the application system of quantitative diagnosis technology in modern automotive fault.

Abstract: The clogging problem occurs in the dewatering projects of sludge with high water content and high clay particles content can be solved by the aeration-vacuum dewatering method. And the water in the sludge can be separated out quickly. Through the dewatering model test of the sludge with this method, the effects of vacuum degree and aeration rate on the dewatering results are studied. The relationship between the initial and final water content is got under the aeration-vacuum condition. Through the fitting analysis of the dewatering curves, the predict model for water content of dredged sludge is presented. And the effect mechanism of the vacuum degree and aeration rate are analyzed.

Abstract: The aeration-vacuum dewatering method is a new kind of solid-liquid separate technique. The filter clogging problem in the routine vacuum dewatering procedure of sludge can be solved by the method. This method is used to dewater the sewage sludge in this paper. Through the dewatering model test of the sewage sludge with this method, the change law of the solid content and the volume of the sewage sludge are studied. The dewatering effect of sewage sludge is got further more. The test results indicate that there is a great promotion for improving the solid content and reducing the volume by using the aeration-vacuum method.

Abstract: Since the reform and opening, China's economy has achieved remarkable results, for various industries have developed rapidly. After 2 decades, 1950s and 1990s, China's vacuum industry also has get dramatic development and vacuum equipments have been widely applied in the electronics industry, especially in the semiconductor and integrated circuit production. This paper described the detection process and method of high vacuum magnetron sputtering equipment, utilized the one-by-one elimination to determine the key emphasis in work and succeeded in finding the cause of the substantial decline in the vacuum degree, then elaborated the results and effectiveness of detection, and finally made a conclusion. This paper has a referential significance on the maintenance of the same kind equipment.

Abstract: Air-jet pump as the pneumatic source of a vehicle-mounted vacuum toilet provides the vacuum to pump the fecal sewage out of toilet bowl via the compressed air passing through the pump under certain pressure. In this study, Computational Fluid Dynamics (CFD) technique is employed to investigate the effects of three important air-jet pump geometry parameters: the primary Nozzle Exit Position (NXP), the constant-area section length (L₁) and the diffuser diverging angle (θ), on its performance. A CFD model is firstly established according to 1D analytical method, and then used to create 135 different air-jet pump geometries and tested under different operating conditions. The significance of this study is that these findings can be used to guide the adjustment of NXP, L₁ and θ to obtain the best air-jet pump performance when the operating conditions are different.