What are the factors that affect the effect of air flow superfine mill?

In recent years, with the rapid development of Chinese traditional medicine industry, the machinery and equipment industry related to the deep processing of Chinese herbal medicine industry also ushered in more development opportunities. In the pharmaceutical production process, particle size is very important for drug bioavailability, so comminution is a very key link. Because of low grinding temperature, short production cycle, high powder rate, uniform and fine particle size distribution, airflow mill has become a useful assistant in the pharmaceutical grinding process.

It is understood that the airflow grinder is also known as the airflow mill, jet mill or flow mill, is a kind of use of high-speed airflow (300-500m/s) or superheated steam (300-400℃) energy of the solid material ultrafine crushing of mechanical equipment. As one of the commonly used ultrafine crushing equipment, airflow crusher is widely used in chemical materials, medicine and food, metal powder and other ultrafine crushing and crushing molding of superhard materials.

Customers said that the airflow crusher crushing particle size range is wide, the operation is simple and convenient, but in the grinding process, there is often a different crushing effect. How does that work? The technical personnel of a powder equipment enterprise said that the crushing effect of the airflow crusher is mainly affected by the following factors: gas-solid ratio, feed particle size, working medium temperature and pressure, and crushing auxiliaries.

Gas-solid than

It is understood that the gas-solid ratio of airflow crusher is an important technical parameter and an important indicator when it is crushed. If the gas-solid ratio is too small, the kinetic energy of the airflow will be insufficient, which will affect the fineness of the product. However, if the gas-solid ratio is too high, it will not only waste energy, but even deteriorate the dispersibility of some pigments.

Therefore, the technical personnel suggest that when the user uses superheated steam as the working medium, the gas-solid ratio of the hard material after grinding and calcination is generally controlled at 2 ~ 4:1, and the material after grinding and surface treatment is generally controlled at 1 ~ 2:1.

Feed particle size

When crushing hard materials, there are strict requirements for the particle size of the feed. In terms of titanium powder, the grinding calcination material needs to be controlled in 100 ~ 200 mesh; The material after grinding surface treatment is generally 40 ~ 70 mesh, not more than 2 ~ 5 mesh.

Temperature of working medium

When the temperature of the working medium is too high, the gas moves faster, technicians say. Taking air as an example, the critical speed at room temperature is 320m/s. When the temperature rises to 480℃, the critical speed can be increased to 500m/s, that is, the kinetic energy increases by 150%. Therefore, increasing the temperature of working medium is conducive to improving the crushing effect.

In addition, when crushing titanium powder, the temperature of superheated steam is generally about 300 ~ 400℃. Technical personnel said that usually the grinding calcination temperature is high, the grinding surface treatment of the material is lower, "some surface treatment agent, especially the organic surface treatment agent is not high temperature resistance, so only need to superheat 100℃ on the basis of the original steam temperature."

The pressure of the working medium

It is understood that the pressure of working medium is the main parameter to produce jet flow velocity, and also the main parameter to affect the grinding fineness.

In general, the higher the pressure, the faster the velocity, the greater the kinetic energy. So, how high pressure should you choose for crushing? Technical personnel said, this mainly depends on the material can be pulverized and fineness requirements. For example, when crushing titanium powder with superheated steam, the steam pressure is generally 0.8 ~ 1.7mpa, and the general crushing calcined material is higher, and the material after crushing surface treatment can be lower.

Crushing additives

Technical personnel said that the airflow crusher in the process of crushing, if the addition of appropriate crushing additives, not only can improve the efficiency of crushing, but also improve the dispersion performance of the product in the medium. So how to choose comminution auxiliaries?

It is understood that titanium dioxide surface treatment, most of the organic surfactants added have the function of crushing additives, and inorganic crushing additives generally use sodium h6-metaphosphate and sodium pyrophosphate (potassium).

In recent years, with the rapid development of Chinese traditional medicine industry, the machinery and equipment industry related to the deep processing of Chinese herbal medicine industry also ushered in more development opportunities. In the pharmaceutical production process, particle size is very important for drug bioavailability, so comminution is a very key link. Because of low grinding temperature, short production cycle, high powder rate, uniform and fine particle size distribution, airflow mill has become a useful assistant in the pharmaceutical grinding process.

It is understood that the airflow grinder is also known as the airflow mill, jet mill or flow mill, is a kind of use of high-speed airflow (300-500m/s) or superheated steam (300-400℃) energy of the solid material ultrafine crushing of mechanical equipment. As one of the commonly used ultrafine crushing equipment, airflow crusher is widely used in chemical materials, medicine and food, metal powder and other ultrafine crushing and crushing molding of superhard materials.

Customers said that the airflow crusher crushing particle size range is wide, the operation is simple and convenient, but in the grinding process, there is often a different crushing effect. How does that work? The technical personnel of a powder equipment enterprise said that the crushing effect of the airflow crusher is mainly affected by the following factors: gas-solid ratio, feed particle size, working medium temperature and pressure, and crushing auxiliaries.