Given the problem of the long time required for testing gas pressure, we propose a fast-test method in which we used a technique of fast borehole sealing and air replenishing. Based on the characteristics of gas emiss...Given the problem of the long time required for testing gas pressure, we propose a fast-test method in which we used a technique of fast borehole sealing and air replenishing. Based on the characteristics of gas emission from boreholes to be tested, we built a theoretical model for calculating parameters during the process of increasing natural pressure and aeration. Using this model, we investigated the effect of different aeration conditions on velocity of pressure tests. The result shows that: 1) aerating air into boreholes can speed up gas pressure tests and 2) the more similar the pressure of the aerated air to the original gas pressure, the smaller the gas volume absorbed by coal and the shorter the time needed in pressure test. A case study in the Lu’an mining area shows that the time needed for gas pressure test is only 4 h using our method of aeration and 29 h under conditions of increasing natural pressure, saving time by 86.2%. This case study also indicates that, by using the aeration method, only one hour is needed for gas pressure to reach a stable state, which breaks the record of the shortest time needed for gas pressure tests in China.展开更多
This paper presents some problems related to water quality and the condition of lakes in Romania, as well as methods for improving the quantity of oxygen dissolved in water. A method for water aeration and the install...This paper presents some problems related to water quality and the condition of lakes in Romania, as well as methods for improving the quantity of oxygen dissolved in water. A method for water aeration and the installation used to implement it are described and the associated advantages regarding the reduction in the level of eutrophication are highlighted. The hydraulic installation for improving the quality of water from lakes, basins, reservoirs or slow flowing rivers was designed and tested in our hydraulics laboratory during a research project. It is floatable, environmentally friendly, and energetically autonomous, being powered by photovoltaic panels, which together with rechargeable batteries can assure a continuous operation. This installation could also be used in early stages of wastewater treatment. Experimental results regarding the performance curves of the hydraulic installation are also presented.展开更多
基金Project 2006CB202204-3 supported by the National Basic Research Program of China
文摘Given the problem of the long time required for testing gas pressure, we propose a fast-test method in which we used a technique of fast borehole sealing and air replenishing. Based on the characteristics of gas emission from boreholes to be tested, we built a theoretical model for calculating parameters during the process of increasing natural pressure and aeration. Using this model, we investigated the effect of different aeration conditions on velocity of pressure tests. The result shows that: 1) aerating air into boreholes can speed up gas pressure tests and 2) the more similar the pressure of the aerated air to the original gas pressure, the smaller the gas volume absorbed by coal and the shorter the time needed in pressure test. A case study in the Lu’an mining area shows that the time needed for gas pressure test is only 4 h using our method of aeration and 29 h under conditions of increasing natural pressure, saving time by 86.2%. This case study also indicates that, by using the aeration method, only one hour is needed for gas pressure to reach a stable state, which breaks the record of the shortest time needed for gas pressure tests in China.
文摘This paper presents some problems related to water quality and the condition of lakes in Romania, as well as methods for improving the quantity of oxygen dissolved in water. A method for water aeration and the installation used to implement it are described and the associated advantages regarding the reduction in the level of eutrophication are highlighted. The hydraulic installation for improving the quality of water from lakes, basins, reservoirs or slow flowing rivers was designed and tested in our hydraulics laboratory during a research project. It is floatable, environmentally friendly, and energetically autonomous, being powered by photovoltaic panels, which together with rechargeable batteries can assure a continuous operation. This installation could also be used in early stages of wastewater treatment. Experimental results regarding the performance curves of the hydraulic installation are also presented.