2015年5月3日星期日

Determination of the true density and apparent molecular sieve catalyst density

Determination of true density, commonly used nitrogen replacement method in a vacuum adsorption capacity device. Atmosphere can enter all the pores of the sample itself is rarely to be adsorbed, without chemical change, is the ideal replacement media. If nitrogen is not readily available, nor require very strict, the organic liquid or water may be used in place of benzene, isopropanol and the like. These alternative molecular substances can only allow them to enter the cross section of a molecule into the pores, but can not enter all the pores of the sample, so had an approximate density side is the matrix density, i.e., apparent density Pa.
Isopropyl drunk fluidized catalyst for dehydration of ethanol replacement method is more commonly used measurement method Pa. This method has been recommended Weld density bottle and a feeding device with a capillary stopper. Pre-test sample with water and isopropyl alcohol in the side of the density of a given temperature correction ju bottles. After the sample is added to the density of the bottle, said the quality of the sample, and then pull the plug capillary tube. The density of the bottle mouth set in the ground on the charging device following grinding mouth tube, evacuated, while adding isopropyl drunk part in a test tube feeding device. When the pressure is less than the sample Ou on "133. 322P. When the rotary piston, so slowly adding isopropanol sample, then put the new capillary density injustice bottle stopper, at a given temperature side after weighing balance. According to these mass and temperature of the water at the side of a given density,
Hue grain density meter is filled with mercury, although the determination of the appropriate, measured before first checking for leaks glass piston. After the first six piston pump is turned on, open the piston 4 is evacuated for some time, with 7 mercury pressure gauge to check the connection of the piston vacuum. Once confirmed the formation of a vacuum, and then close the piston 4 and 7. 6 rotary piston slowly into the atmosphere after the pump stops. Slowly open space filled with mercury piston 3 2, closed when the mercury rose to the surface of the piston 4 position 3, this time on the left to read the calibration tube demand side of the piston Liu, set V1 (MI.), And then put through the piston 4 into the atmosphere. Open the piston 3, so that the mercury level drops. When the lid 5 open mill, into the weighed sample grain sheet, as before re-operation. Read volume V3 (mL), mercury surface down to the proper position, the piston 3 to close and open the cover 5 day wear, Samples were taken with a teaspoon.

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