Advanced Materials Research Vol. 508

Abstract: This paper presents a quantitative method of measuring the volume of material stack.The material stack is divided into many little rectangular columns,then the material stacks volume will be got by calculating each rectangular columns volume.At the same time,a measurement system is designed to achieve the automatic measurement, three-dimensional reconstruction, and volume measurement.

Abstract: This paper introduced the measure methods model and principles of Permeability in the ECK-; the uncertainty source for the measure results was analyzed in detail. Combined with the test and calibration works; the mathematical model was established; considering each uncertainty component which affected the measure results of rock permeability. The standard samples of cores; A38(length:2.495cm;diameter:2.456cm);was taken for example. The uncertainty of measure results was carried out by type A and B estimation; the relative uncertainty of the method was calculated. Through reasonable evaluated the components of uncertainty which including causing uncertainty by pressure changing; temperature changing; stability of the measure instruments and vernier caliper reading error. The uncertainty from stability of the measure instruments was detailedly analyzed by the line graph. By evaluating uncertainty of rock permeability in measure results; we find that the biggest influence on total standard uncertainty is the core size; so in the work the operators experimental skills should be paid great attention to.

Abstract: We develop the research on macrograph grain size analysis method of tight gravel-rock, in allusion to the difficulty in conducting the grain size analysis due to difficult dissolution of oversized rock particles with adamant lithology in deep-seated natural gas conglomerate reservoir in Daqing Songliao Basin. The research includes the establishment of coarse clastic grain grade scale, sample selecting, grain extraction, data processing method, and so on. This testing method meets the requirements of the grain size analysis of the coarse clastic rock with grain diameter more than 4000 micron, gives the features of the grain size distribution and provides references to deposition reservoir research.

Abstract: The powder with size distribution was made from eruption to be used for the simulant of lunar soil. One of the most important factors is shear property, to simulate lunar soil behavior under the rover wheels. Therefore, it is necessary to measure the shear parameters of the simulant. The direct shear detector with controlled sample weight was used for selecting suitable method to obtain the shear parameters of the simulant, and finding effect actors for the measurement. Results found that the parameters changed greatly with the powder bulk density (or unit weight), and the calibration was vitally important for measuring cohesion of the powder.

Abstract: Petrophysical parameters are not only concerned with grain size, but also with the cementation degree. Therefore, it is difficult to determine the petrophysical parameters for the loose core using traditional testing technique. This paper discussed the influence of freeze-sampled loose rock on the test result of rock porosity and permeability. In view of the grains scattering problem in oil-bearing loose rock samples caused by sample deoil, the calibration method for rock permeability and porosity is proposed in this paper through the comparison of testing methods. The test result indicates that the method of measuring the rock permeability of the oil-bearing samples followed by measuring the rock porosity of the deoiled samples is effective. This method can meet the requirements during sample deoiling, drying and petrophysical parameters testing, decrease the influence of freeze-sampling technique on the test of petrophysical parameters, resolve the difficult problem of testing petrophysical parameters using the same sample, and improve the authenticity and reliability of the analyzing result.

Abstract: In this study, raw materials in five different commercially available size ranges were mixed to prepare blank for Al₂O₃-MgO-C refractories. In the light of close packing theory, the optimization model for getting the optimum grain gradation was founded. And optimum ratio for raw materials of different size and distribution character was concluded by solving the model to obtain closest packing. The result shows that stacking density and tap density of the blank came from the particle mixture with optimized grain gradation reached 1.46 and 1.70g/cm³ individually, both were higher than those of the blank made of mixture according to empirical grain gradation. And the microstructures observation result indicated that the voids among aggregate particles in the refractory came from the mixture with optimized grain gradation were separated into small and discrete ones while they were bigger in the refractory produced following empirical grain gradation.

Abstract: Cross correlation techniques have been proved to be a valuable tool for online continuous velocity measurement of particulate solids in pneumatic pipelines. In order to reduce computational complexity the sampling frequency is usually kept as low as possible, and the peak in the correlation function is found by interpolating the correlation function. Parabola functions are commonly used as parametric models of the cross correlation function in time delay estimation. However, the parabolic-fit interpolation method introduces a bias at low sampling rate to the center frequency ratio of input signal. In this paper, a combined interpolation method is proposed to improve the estimation accuracy. Experiments are carried out to evaluate the performance of the proposed interpolation method for low sampling rate. The experimental results have been promising and have shown the potential of the proposed method for particle flow velocity measurements.

Abstract: This paper introduces a prototype multiphase flow metering system, named Uletech, for multiphase flow measurement. The Uletech Multiphase Flow Meter (UMFM) is based on the combination of particle recognition and the use of Laser Imaging Technology in the form of Particle Imaging Velocimetry (PIV). PIV uses tracer particles which follow the gas or liquid phase. The high resolution digital laser cameras identify/recognize all the different sizes of particle (gas, oil and water) in a multiphase flow. The cameras have sufficiently high resolutions (pixel size) to "see" the tracer particles. The prevailing conditions of high pressure and temperature of the flow regimes makes actual measurement a great challenge. The velocity differences between phases (hold up and slip) means unless the velocities of individual phases and concentrations are known, the true flow rate is practically impossible to obtain. The system comprised of two cameras, laser source, optical arrangement, computer data acquisition system, synchronizer and MATLAB based software. An algorithm that correlates the cameras view to the volume within the pipe has been developed through this research. The computer acquires image signals from the upstream and/or downstream cameras, and carries out the calculation of cross correlation between the two image frames so that the velocity of each pixel can be found. A Gas Liquid Chromatograph (GLC) provides the composition (concentration) of the gas and the liquid hydrocarbon (HC). The product of phase velocity and phase concentration provides the flow rate of the individual phase. This work provides theoretical analysis and experimental validations, and discusses the advantages of the system and its further development.

Abstract: The application of process tomography (PT) technologies, i.e. Electrostatic Tomography (EST) and Electrical Capacitance Tomography (ECT) to investigate complex industrial processes has obtained wide popularity in recent years. This study focuses on the characterization of non-uniformly distributed electrostatic effects across the cross-section of a pneumatic transportpipe. A digital electrometer was used to measure the electrostatics current and an ECT was used to observe the particle distribution in a vertical pipe. Due to non-uniform particle-wall collisions, the electrostatics generated was observed to be non-uniformly distributed across the pipe cross-section, especially at pipe bends and in a vertical pipe. Large electrostatic effects were associated with high particle concentration in the pipe. There was a good correspondence between the electrostatic effects measured and particle concentration distributions obtained using ECT. Based on ECT measurements at the vertical pipe section, it was observed that particles tended to concentrate at sections where generation of electrostatic charges was high. Thus, it is clear that electrostatic effects should be the key factor giving rise to non-uniform particle concentration distribution in pneumatic transport lines.

Abstract: When original data is not complete or image degenerates, image reconstruction and recovery will be very important. In order to acquire reconstruction or recovery image with good quality, compressed sensing provides the possibility of achieving, and an image reconstruction algorithm based on compressed sensing with split Bregman method and fuzzy bases sparse representation is proposed, split strategy is applied in split Bregman algorithm in order to accelerate convergence speed; At the same time, discrete cosine transform and dual orthogonal wavelet transform are treated as bases to represent image sparsely, and image is reconstructed by using split Bregman algorithm. Experiments show that the proposed algorithm can improve convergence speed and reconstruction image quality.