生石灰处理高含水率疏浚淤泥的含水率变化规律研究

通过大量的室内试验,研究了高含水率疏浚淤泥添加生石灰拌和而成的松散土的含水率变化规律。导入含水率降低率的概念,得出处理土含水率降低率随掺灰比的变化与原泥初始含水率无关,含水率降低率随着掺灰比的增加而线性增加的变化规律。根据得出的含水率变化规律,提出了处理土含水率的简单实用的预测方法。利用已有文献的试验数据验证了所提出的处理土含水率的变化规律和预测方法的有效性。

延安组底水油藏注水开发特征及注水优化—以D区块为例

D区块为岩性—构造油藏,具有边底水特征。文章通过对D区块注水开发特征分析,认识到:该类油藏注水开发时应控制注、采速度,温和注水,温和采油。通过开发实践,D区块适宜的注采比为0.8—1.0,适宜的井底流压为2.5—3.5MPa。

Microwave drying characteristics and kinetics of ilmenite

The microwave drying of ilmenite was investigated.The effects of power levels and sample mass on drying characteristics of moisture content,drying rate,moisture ratio were studied,with microwave power ranging from 119 W to 700 W and sample mass from 5 g to 25 g.The drying processes were completed within 2-8 min at different conditions.The moisture content and drying rates are found to be dramatically affected by microwave power density.For all drying processes the prior microwave absorption of moisture produces an accelerating peak on the drying rate curves in the initial stage.For the sample mass of 25 g and power of 385 W,the drying kinetics were studied.The experimental results fit better to the Henderson-Pabis index model rather than the Page＇s semi-empirical model;the drying rate constant k is increased with the increase of microwave power and decrease of sample mass.

Operation Effect of Water Control System for Beddings of Pig-raising Deep-litter Systems

[Objective] The study was conducted to optimize the operation parameters of water control equipment for deep-litter beddings. [Method] A four-factor three-level orthogonal design was adopted to optimize experimental temperature, stopping time of aeration, aeration time and aeration rate by 9 groups of experiments, so as to improve the water removal efficiency of adopted mixed and reduce operation energy consumption. [Result] The average water contents in the mixed bedding under 3 temperatures decreased by 4.58% ±2.91%, 13.17% ±3.77% and 10.8% ±7.72%, respectively; the highest water removal efficiency could be achieved under an experimental temperature at 45 ℃, stopping time of aeration of 15 min, aeration time of 7 min, and an aeration rate at 4 m^3/min, which formed the optimal factor combination mode of the operation parameter of the water control equipment; the effects of various experimental factors on water content in the bedding were in order of aeration ratetemperatureaeration timestopping time of aeration; and the effects of various experimental factors on water removal efficiency in the bedding were in order of temperatureaeration rateaeration timestopping time of aeration. [Conclusion] After the optimization of operation parameters of the water control equipment for the deep-litter bedding, water removal efficiency of the mixed bedding could be improved, and the operation energy consumption of the equipment could be reduced.

填筑土体压实度快速检测试验

针对平原水库围坝填筑压实度快速检测做了大量的"三点击实"和标准击实试验。分析了三点击实试验过程中减水情况及加、减水情况下试验方法的可行性及其数据合理性,和标准击实试验方法进行了比较,认为减水情况及加、减水情况下试验方法是可行的,在减水情况下最优含水率和填土含水率的差值一般在-3%～0,同时试验过程中土体减水率小于6%时,三点击实试验成果比较合理。用三点击实试验方法填筑土体压实度所用时间比标准击实试验的方法省6～8h,三点击实试验填筑土体压实度的方法针对土体特性差别较大的工程中适用性强。提出了减水情况下的三点击实试验步骤及试验过程中的注意事项。

Isothermal diffusion of water vapor in unsaturated soils based on Fick’s second law

In arid regions, water vapor diffusion predominates the total water migration in unsaturated soil, which significantly influences agriculture and engineering applications. With the aim of revealing the diffusion mechanism of water vapor in unsaturated soil, a water vapor migration test device was developed to conduct the water vapor migration indoor test. The test results demonstrate that the characteristics of water vapor diffusion in unsaturated soil conformed to Fick’s second law. A mathematical model for water vapor diffusion under isothermal conditions in unsaturated soil was established based on Fick’s law. Factors including the initial moisture content gradient, initial moisture content distribution, soil type and temperature that affect the water vapor diffusion coefficient were analyzed. The results show that there was good agreement between the moisture content calculated by the mathematical model and obtained by the indoor experiment. The vapor diffusion coefficient increased with increasing initial moisture content gradient and temperature. When the initial moisture content gradient is constant, the vapor diffusion coefficient increases with the increase of matrix suction ratio in dry and wet soil section. The effect of soil type on the water vapor diffusion coefficient was complex, as both the moisture content and soil particle sizes affected the water vapor diffusion.

Drying Characteristic of Anchovy Fish

This paper focuses on the drying characteristic of anchovy fish （Anchovia engraulidae）. It is necessary to understand the drying behavior, quality of the products and time required to optimize the energy consumption of the process. The optimum velocity and temperature of drying air for good quality dried anchovy fish was determined. In average, the fish are 7 cm in length and 3.0-3.5 g in mass. Although some research on fish drying has been done, the study of drying of anchovy fish and its characteristic has not been well reported. The fish to be dried were arranged on 15 × 15 cm2 tray in the drying chamber of 17 × 30 cm2. The hot air of 40 -70 ℃ was delivered parallel to the tray with the velocity of 0.6 and 0.9 m s-1. It is found that thermal conductivity （k） and specific heat （cp） of anchovy fish are function of the moisture content （MC）. The higher moisture content results in higher thermal conductivity and specific heat. Critical water content is also found in this experiment as well as the optimum drying condition. Drying rate period of anchovy fish will change from the constant drying rate period to the falling drying rate period when critical moisture content is about 48.8%-50.3% （wet basis）. At these experiments, there is no case-hardening, even at temperature of 70 ℃. To achieve the optimum result, the drying process should be implemented in three steps, drying process at 70 ℃ for 150 min followed by drying at 50℃ for 100 min, and finally drying at 40℃ till achieving equilibrium moisture content. This research will contribute to improvement of drying method to achieve good quality of dried fish.