Particle size testing of basic skills
granularity test is through specific instruments and methods for the characterization of particle size characteristics of an experimental work. Powder in our daily lives and is widely used in industrial and agricultural production. Such as flour, cement, plastic, paper, rubber, ceramics, medicines and so on. In the different areas of application, requirements for powder characteristics, is not the same, all the indicator of powder characteristics and particle size distribution in all areas of application is an indicator of the most closely watched. So truly and objectively reflect the size distribution of powder is a very important piece of work. Here I specifically on particle size testing of base knowledge and methods.
one, basic knowledge of particle size testing
1, particles: a specific size range with the geometry of the shape. Here a dimensions in mm between the nano-particles not only refers to the solids, and droplet particles, oil and other liquids.
take 2, powder: made up of lots of different size particles particles.
3, size: the size of particles is called particle size.
4, particle size distribution: with specific instruments and methods reflect the percentage of the total amount of particles with different diameters powder. Interval and cumulative distributions in two forms. Zone distribution is also known as differential or frequency distributions, it represents a series of particles in the size range of content. Also called cumulative distribution points distribution, which represents less than or greater than a certain particle content.
5, the particle size distribution of representation:
① table method: using the table method of particle size distribution, the cumulative distribution list method.
II graphics method: in Cartesian coordinate system using histogram and curve, representation method of particle size distribution.
③ function method: the method of particle size distribution of mathematical functions. This method in theoretical research. Such as the famous Rosin-Rammler distribution is the distribution function.
6, diameter and equivalent grain size: the
size is the grain diameter. This concept is is simple clear of, so what is equivalent grain diameter does, grain diameter and equivalent grain diameter has what relationship does? we know, only ball body is diameter, other shape of geometry is no diameter of, and composition powder body of particles and most not round spherical of, but various not rules shape of, has tablets-like of, and needle-like of, and more ribs-like of and so on. The complex shape of the particle theory is not directly used the concept to represent its size in diameter. In practical work, describing a particle size diameter the most intuitive, simple, and we hope can be described in terms of such a size, so in-grained in the practice of testing we have introduced the concept of equivalent size.