摘要:

AbstractThe performance of a narrow‐angle and a wide‐angle, forward scattering laser aerosol spectrometer has been studied as a function of particle size and refractive index. The results have been compared with theoretical calculations based on light scattering theory. The results indicate that for the narrow‐angle instrument, the scattered‐light intensity is not a monotonic function of particle size for transparent particles (a monotonic relationship is required for unambiguous particle size measurement) above 0.7 μm. The instrument is therefore limited in its useful range to size distribution measurement between 0.2 μm – its lower particle size limit – and 0.7 μm for transparent particles. In the case of the wide‐angle instrument, the instrument output is a monotonic function of particle size for transparent particles, but the output is severely attenuated for light absorbing particles above 0.3 μm. The instrument, therefore, cannot be used for accurate size measurements above 0.3 μm for light a

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030102

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractCascade impactors are still the most suitable devices with which to measure fine droplet mists in gas ducts. This report describes the measurement technique and underlying principles. It is based largely on experience gained with a type of impactor that has been specially developed for droplet measurements, and also on applications of impactors in the chemical industry. Most of the measurement work has been undertaken in connection with environmental protection. The cascade impactor gives the mass‐related droplet size distributions and concentrations within a range extending from about 0.2 to 10 microns. Larger droplets are collected quantitatively in the sampling probe, which serves as a precollecto

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030103

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractThis study deals with measurements of the drop‐size distributions of different types of fan spray atomisers using a scattered‐light particle size counting analyser. The drop‐size distributions were determined at various locations in the spray cone. These local distributions change systematically from the fan's axis to its border. Superimposing these local distributions, adequately weighted, one acquires the entire distribution of all the drops. A comparison of the experimental results is made with those yielded by mathematical equa

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030104

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractStarting fromWheeler's composite theory, which takes both the multilayer adsorption and the capillary condensation into consideration, and assuming the equivalent cylindrical model, we have deduced a strict and relatively simpler formula for the calculation of pore size distributionby solving the integral equation directly. The formula is more convenient for application because of its recursion form. Following the same line of reasoning and using the mean value theorem of definite integrals under different conditions, we have unified the equations ofBarrett‐Joyner‐Halenda, Dubinin, Cranston‐Inkley, Dollimore‐HealandRoberts. A table of parameters which is required in the calculation is given. Besides the adsorption of nitrogen, the adsorption with water vapor as the adsorbate is investigated and the corresponding empirical equation of adsorption thickness i

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030105

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractParticle size enlargement operations often involve the use of a liquid to improve powder cohesiveness. Capillary suction and surface tension forces acting through liquid menisci between particles are the primary source of the cohesive bonding. The strength of these forces, and consequently the strength of the wet agglomerate, is dependent upon the total liquid content, its distribution within the agglomerate, and the powder wettability (characterized by the liquid surface tension and powder/liquid contact angle).The tensile strength of powder compacts containing submicron carbon black particles has been measured as a function of saturation level for several liquids. It is found that the compact strength increases with increasing surface tension for liquids that exhibit a zero contact angle. Above the critical surface tension for wetting a more complicated situation exists where both the surface tension and contact angle are important.

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030106

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractWithin grinding machines the load acting on the particles and the loading rate are widely distributed. According to studies on the breakage mechanism of brittle materials, the mechanical properties which relate to breakage vary with the loading rate. In order to elucidate the grinding mechanism within the grinding machines, it is necessary to obtain the relationships between these properties and loading rate.In this study, the variation of strength, fracture energy, new surface area produced by fracture and fracture energy with the loading rate (ranging from 10−1to 109N/s) was investigated by means of compression tests on a large number of spherical specimens. As a result, a singularity of crushing behavior was observed under an impact loading corresponding to a duration of time of loading the same as the natural period of the spherical specimen. The crushing efficiency is especially at its maximu

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030107

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractTwo types of asbestos fiber, chrysotile and amosite, form filter cakes of different permeabilities while having a similar degree of dispersion.The filter cake resistance depends on the disperse phase characteristics and the conditions of cake formation. The main reason for the effects mentioned is different particle flexibility influenced by the specific structure of each type of asbestos particle.The flexible chrysotile fibers in the cake form dense and rigid, amosite, porous deposits. An increase in the velocity of the suspended chrysotile particles, caused by pressure difference and agitation, results in significant differences in filter cake resistance.

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030108

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030111

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

ISSN:0934-0866    

DOI:10.1002/ppsc.19860030101

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY