PARTICLE COUNTING OIL AND WATER EMULSIONS

Because of their speed and convenience, optical particle counters are widely used for particle size analysis of liquid samples. In some cases, both solid particles and emulsified water or oil may be present in a sample. Since emulsion droplets are counted as if they are solid particles, analysis and data interpretation for these samples are difficult. Until recently, no suitable method existed for distinguishing solid contaminants from emulsion droplets. This paper discusses a method which overcomes this limitation. Through the use of a surfactant-laden nonpolar dilution fluid, water is incorporated into reverse micelles too small to be seen by most optical particle counters. As a result, only solid contaminants are counted, and many problems associated with the analysis of emulsions are overcome. Results obtained from a wide range of oil and water emulsions are used to evaluate the merits and possible applications of the new technique.     

MEASUREMENT OF PARTICLE SIZE DISTRIBUTION IN COAL OIL WATER FUELS BY FOUR METHODS

ABSTRACT

Four methods were used to measure the solids particle size distribution in coal-ol1-water fuel. Both dry and wet screening were utilized for the coarser particles while four different instrumental methods were used to measure the finer particles in diluted liquid suspension. The wet stages of the analyses included both solvent-diluted organic suspensions and measurement after inversion to an aqueous system.

Consistent differences in the absolute values of particle size were observed between the four procedures. Possible reasons for these differences are discussed.     

MEASUREMENT OF PARTICLE SIZE DISTRIBUTION IN COAL OIL WATER FUELS BY FOUR METHODS

Four methods were used to measure the solids particle size distribution in coal-ol1-water fuel. Both dry and wet screening were utilized for the coarser particles while four different instrumental methods were used to measure the finer particles in diluted liquid suspension. The wet stages of the analyses included both solvent-diluted organic suspensions and measurement after inversion to an aqueous system.

Consistent differences in the absolute values of particle size were observed between the four procedures. Possible reasons for these differences are discussed.     

THE PROPER USE OF WATER LIQUID PARTICLE COUNTERS

ABSTRACT

In the present work the removal of iron, present as impurity in a kaolin of industrial interest, was performed. An effective iron reduction using microbial mixed cultures was attained (up to 81%) while a significant iron reduction in the presence of single microbial cultures was achieved (up to 37%).

The active microorganisms belong to the genera Bacillus and Agrobacter. The enzymatic and un-enzymatic iron reduction was evaluated.

Finally the molasses as carbon source for heterotrophic bacteria were succesfully tested.     

水和油脂对硝酸铵热稳定性的影响

为了研究水和油脂对硝酸铵热稳定性的影响规律,采用FCY 1型发火点测定仪测定爆发点的方法对含有不同杂质的硝酸铵的热稳定性进行了研究。实验结果表明,纯硝酸铵中加水至硝酸铵质量分数为95%时,爆发点由333.65℃降至311.69℃,热稳定性降低,继续加水至硝酸铵质量分数为85%时,爆发点略微升高至317.79℃,热稳定性略微增强。在95%硝酸铵中加入油脂至油脂质量分数为3.85%时,爆发点降至295.66℃,热稳定性降低。     

水和油脂对硝酸铵热稳定性的影响

为了研究水和油脂对硝酸铵热稳定性的影响规律,采用FCY-1型发火点测定仪测定爆发点的方法对含有不同杂质的硝酸铵的热稳定性进行了研究.实验结果表明,纯硝酸铵中加水至硝酸铵质量分数为95％时,爆发点由333.65℃降至311.69℃,热稳定性降低,继续加水至硝酸铵质量分数为85％时,爆发点略微升高至317.79℃,热稳定性略微增强.在95％硝酸铵中加入油脂至油脂质量分数为3.85％时,爆发点降至295.66℃,热稳定性降低.     

颗粒统计平均粒径及其分布的表征

讨论了颗粒形状和大小的表示、粒径测定、平均粒径和粒径分布的表征等问题,用实例比较了３种粒径分布较典型的乳液样品的各种平均粒径差异;根据粒子数计算公式的含义分析和统计平均粒径的物理意义,认为用于计算粒子数的平均粒径应为体均粒径,提出有关的一些建议。     

TOTAL PARTICLE MONITORING AND DETECTION

ABSTRACT

One of the methods of detecting particles in the ultrafine size range (diameter <0.05 μm) is by condensation nuclei counters. Such condensation nuclei counters have a broad range of application including clean room monitoring, the characterization of contaminants in fossil energy process streams, and atmospheric monitoring. Based on the condensation of a saturated vapor, the method can amplify the size of the particles which are being studied by several orders of magnitude so that they can be detected by standard optical methods. However, the lower size limit of detectability is dependent on the proper choice of parameters that create the saturation conditions.

This paper presents results of the counting sensitivity tests of two condensation-type counters (the Pollak and the Sinclair continuous-flow counters). The results indicate that these instruments should be operated close to the self-nucleation limit in order to ensure total particle counting.     

PARTICLE MORPHOLOGY AND BULK PROPERTIES

Experimental results relating bulk properties to newly developed shape terms are presented in this paper. The properties studied are tap density, apparent density, processing parameter, flow time, and angle of internal friction of several materials. The correlations obtained demonstrate the utility and the potential of morphological analysis.     

PARTICLE MORPHOLOGY AND BULK PROPERTIES

ABSTRACT

Experimental results relating bulk properties to newly developed shape terms are presented in this paper. The properties studied are tap density, apparent density, processing parameter, flow time, and angle of internal friction of several materials. The correlations obtained demonstrate the utility and the potential of morphological analysis.     

混合颗粒床中颗粒轨道模型及其数值模拟

以含粒状、管状火药的混合装药结构火炮为工程背景，建立离散的颗粒轨道模型。气相用欧拉法描述，颗粒相和管状药用拉格朗日方法描述。两相的相互作用反映在守恒方程的源项中。并用数值方法进行了求解，计算膛压和初速与实验有较好的一致性。     

聚氨酯-聚丙烯酸酯共聚乳液的成膜和性能

通过XPS和接触角测试研究了聚氨酯-聚丙烯酸酯共聚乳液在不同基材上的成膜情况，并对共聚胶膜的耐水性和附着力进行了考察．由于该共聚乳液同时存在着亲水组分和疏水组分，所以它在不同的基材上成膜可导致其膜表面的组成成分不同，因而导致其耐水性和附着力也随基材而异。结果表明，亲水性的聚氨酯组分均富集于胶膜内部，但胶膜底层聚氨酯组分的含量却随基材的不同而不同。在憎水且表面张力较高的基材上，共聚胶膜的耐水性良好；共聚胶膜的附着力在表面张力较高的基材上也良好。     

PARTICLE ADHESION AND REMOVAL: A REVIEW

ABSTRACT

A review is given of the factors playing a role in particle adhesion and removal. The emphasis is put on those systems, which are of colloidal nature (so that gravitational effects can be neglected), and which are as close as possible to the sphere-plate model. It is shown that the major interaction forces are the omni-present van der Waals force of attraction and in an liquid environment, in addition, the electrostatic double layer force of repulsion and, in particularly in a polar liquid, the Lewis acid/base force of interaction, which is responsible for hydrophobic bonding. The magnitude of the various interactions depends on the surface properties of the adherents and on the deviations of the idealized model, such as an extended contact area. The latter is also responsible for alterations with time, either as a result of plastic or elastic deformation.

The removal of particles of colloidal dimensions from a solid surface is controlled by the wall shear stress of the flow passing by, and in case of applying an air-liquid interface by the contact angle of the fluid and the adherents.     

PARTICLE ADHESION AND REMOVAL: A REVIEW

A review is given of the factors playing a role in particle adhesion and removal. The emphasis is put on those systems, which are of colloidal nature (so that gravitational effects can be neglected), and which are as close as possible to the sphere-plate model. It is shown that the major interaction forces are the omni-present van der Waals force of attraction and in an liquid environment, in addition, the electrostatic double layer force of repulsion and, in particularly in a polar liquid, the Lewis acid/base force of interaction, which is responsible for hydrophobic bonding. The magnitude of the various interactions depends on the surface properties of the adherents and on the deviations of the idealized model, such as an extended contact area. The latter is also responsible for alterations with time, either as a result of plastic or elastic deformation.

The removal of particles of colloidal dimensions from a solid surface is controlled by the wall shear stress of the flow passing by, and in case of applying an air-liquid interface by the contact angle of the fluid and the adherents.