Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were...Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were investigated. The results showed that the optimum separation parameters were a centrifugal speed at 6 000 r/min, centrifugal time of 20 min, a mass fraction of dry matter of 20%, an inlet air temperature at 180 ℃ and a feed rate at 400 ml/h, under which the plasma protein was a pale yellow powdery solid, indicating a good separation effect.展开更多
In order to obtain appropriate spray pressure and enhance the spraying and dust removal efficiency, various factors including the dust characteristics, nozzle spraying angle, effective spraying range, water consumptio...In order to obtain appropriate spray pressure and enhance the spraying and dust removal efficiency, various factors including the dust characteristics, nozzle spraying angle, effective spraying range, water consumption and droplet size are taken into account. The dust characteristics from different mines and atomization parameters of different pressure nozzles were measured. It was found that the internal pressure of coal cutters and roadheaders should be kept at 2 MPa, which could ensure large droplet size, large spraying angle and low water consumption and hence realizing a large-area covering and capture for large particle dusts. However, the external spray pressure should be kept at 4 MPa for smaller droplet size and longer effective spraying range, leading to effective dust removal in the operator zone. The spray pressure of support moving, drawing opening, and stage loader on a fully mechanized caving face and stage loader on a fully mechanized driving face should be kept at 8 MPa, under which the nozzles have long effective spraying range, high water flow and small droplet size for the rapid capture of instantaneous, high-concentration and small size dust groups. From the applications on the caving and driving faces in the coal mines, it is indicated that the optimization of spray pressure in different spraying positions could effectively enhance dust removal efficiency. Selecting appropriate nozzles according to the dust characteristics at different positions is also favorable for dust removal efficiency. With the selected nozzles under optimal pressures, the removal rates of both total dust and respirable dust could reach over70%, showing a significant de-dusting effect.展开更多
A silver removal process was carried out on a Pb-Ag alloy through zinc powder injection of three different sizes （3.55, 44.4 and 734.8μm） with a top submerged lance using nitrogen as carrying gas. The higher silver...A silver removal process was carried out on a Pb-Ag alloy through zinc powder injection of three different sizes （3.55, 44.4 and 734.8μm） with a top submerged lance using nitrogen as carrying gas. The higher silver removal was obtained for the zinc powder size of 44.4μm, while the lowest silver removal efficiency was attained for the smaller particle size. The AgZn phase was detected in the slag for the 44.4 and 734.8μm particle sizes by XRD, which was in agreement with SEM-EDS analysis. Experimental behavior was explained according to the melting and residence time of the injected particles.展开更多
基金Supported by"123"Science and Technology Support Program from Science and Technology Department of Qinghai Province(2014-GX-136A)~~
文摘Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were investigated. The results showed that the optimum separation parameters were a centrifugal speed at 6 000 r/min, centrifugal time of 20 min, a mass fraction of dry matter of 20%, an inlet air temperature at 180 ℃ and a feed rate at 400 ml/h, under which the plasma protein was a pale yellow powdery solid, indicating a good separation effect.
基金support from the National Natural Science Foundation of China (Nos.U1261205, 51474139 and 51204103)the Science and Technology Development Plan of Shandong Province (No.2013GSF12004)the Excellent Young Scientific Talents Project of Shandong University of Science and Technology (No.2014JQJH106)
文摘In order to obtain appropriate spray pressure and enhance the spraying and dust removal efficiency, various factors including the dust characteristics, nozzle spraying angle, effective spraying range, water consumption and droplet size are taken into account. The dust characteristics from different mines and atomization parameters of different pressure nozzles were measured. It was found that the internal pressure of coal cutters and roadheaders should be kept at 2 MPa, which could ensure large droplet size, large spraying angle and low water consumption and hence realizing a large-area covering and capture for large particle dusts. However, the external spray pressure should be kept at 4 MPa for smaller droplet size and longer effective spraying range, leading to effective dust removal in the operator zone. The spray pressure of support moving, drawing opening, and stage loader on a fully mechanized caving face and stage loader on a fully mechanized driving face should be kept at 8 MPa, under which the nozzles have long effective spraying range, high water flow and small droplet size for the rapid capture of instantaneous, high-concentration and small size dust groups. From the applications on the caving and driving faces in the coal mines, it is indicated that the optimization of spray pressure in different spraying positions could effectively enhance dust removal efficiency. Selecting appropriate nozzles according to the dust characteristics at different positions is also favorable for dust removal efficiency. With the selected nozzles under optimal pressures, the removal rates of both total dust and respirable dust could reach over70%, showing a significant de-dusting effect.
文摘A silver removal process was carried out on a Pb-Ag alloy through zinc powder injection of three different sizes （3.55, 44.4 and 734.8μm） with a top submerged lance using nitrogen as carrying gas. The higher silver removal was obtained for the zinc powder size of 44.4μm, while the lowest silver removal efficiency was attained for the smaller particle size. The AgZn phase was detected in the slag for the 44.4 and 734.8μm particle sizes by XRD, which was in agreement with SEM-EDS analysis. Experimental behavior was explained according to the melting and residence time of the injected particles.
