the application and development of Airflow smashing in titanium dioxide production2012.01.30 09:10
After nearly fifty years of development ，the titanium dioxide industry in China, especially the development of recent five years, the total production capacity and total output has become second only to the United States, become the world's second largest producer of titanium dioxide. But China's production of titanium dioxide from quality and variety, still have certain difference with international advanced level. It has many factors effecting the quality of titanium dioxide, and airflow grinding is the key factor . Here, on the airflow pulverization principle, in titanium dioxide’s production and application and airflow pulverizing system configuration for further instructions.
1 airflow smashing principle and airflow crusher classification
1.1 the principle of airflow smashing
The general principle of airflow smashing:it will dry no oil compressed air or overheated steam through the nozzle accelerate rawalpindi into supersonic airflow, the jet of high-speed jet drive material do high-speed motion, make particle collisions in watts, friction and shattered. The material was crushed by air currents to grading area, reach the final fineness required materials by capture device collection, did not reach the required material back to concave crushing chamber continuing to pieces, and until it reaches fineness and was arrested for set .
Jet mill crushing product besides fine granularity, still have narrow particle size distribution, particle shape neat, high purity, active, good dispersion characteristics.
1.2 the classification of airflow crusher
At present， airflow crusher in industrial application basically has the following kinds of types:
(1) the flat (also called horizontal dise-type) airflow crusher;
(2) circular tube type airflow crusher;
(3) to spray type (also called conflict type) airflow crusher;
(4) target type airflow crusher;
(5) fluidized state to the spray type airflow crusher.
2, the application of airflow smashing in titanium dioxide production
2.1 the requirements of titanium dioxide to crush
As the use of titanium dioxide pigments, excellent optical performance and stable chemical properties. Therefore, to particle size and size distribution of titanium dioxide, it requires very high purity. In addition, it also requires titanium dioxide in different coating system have a good range. Therefore, the general mechanical grinding equipment is difficult to meet the requirements, so the final pieces of titanium dioxide (finished pieces), both at home and abroad are chosen airflow crusher.
2.2 titanium dioxide production on airflow crusher choice
21 century of titanium dioxide industry is one of important progress, which is chosen as the finished product of airflow crusher eventually shattered. According to the requirements of titanium dioxide crushed: narrow particle size distribution and inclusion less, good dispersion and increase, and white material characteristics: high viscosity, poor liquidity, fine granularity easily attach wall etc. Titanium dioxide production factory at home and abroad has successfully levels function which are chosen for the flat (also called horizontal dise-type) airflow crusher as titanium dioxide final crushing equipment; And use the superheated steam for crushing medium.
3 the application and development of Airflow smashing in titanium dioxide production
3.1 the application of airflow smashing
Before the 1980 s, Titanium dioxide industry in China have the relatively slow development, production enterprise for more than 10000 t/a of the small manufacturers, and the product type is more for cheap sharp titanium , and only have few of the production of small enterprise DTT type. From the 1990 s, domestic three companies introduced annual capacity of 15000 t article three of the type of titanium dioxide DTT production line from abroad, white this, big norms of flat gas powder machine only enter into China. By 2000, the domestic big norms air powder has can reach the titanium dioxide machine production requirements, can completely replace the imported equipment, the development of titanium dioxide industry also play a certain role for domestic.
3.2 the development of airflow smashing
With the rapid development of titanium dioxide industry, the requirement for equipments is more and more high. To meet the technological conditions i, the quality requirements, the premise of equipment becoming larger and systematic appears especially important, airflow smashing also with the development of titanium dioxide is improving. Air powder machine from the initial capacity also 1.2 t/h ~ 1.5 t/h, to now 2.5 t/h ~ 3.5 t/h, the production capacity of the air powder system from wired 10000 t/a, now one of 20000 t/a, collect way also is comparatively backward from the wet collection to advanced dry collection, which greatly increased a yield, reduced the waste.
By Zhu Tingting