The purpose of ventilation and fumigation of grain silo
The purpose of ventilation and fumigation is to prevent the stored grains away from the damage of pests, rats or birds. Because they may bring mildew which may case imbalance inside the grain silo. Therefore, to ensure the safety of the grain and achieve better pest killing effect and higher benefits. A good design can guarantee the safety management of grain storage.
It is the most basic condition and important means to ensure the safety of grain are through ventilation and fumigation. Because the steel silo has the characteristic of well sealed, the water content in and temperature inside the grain steel silo has a certain effect on the grain storage.
It is also not easy to dissipate heat and humidity, with big resistance of ventilation airflow, etc. At the same time, because large storage capacity and great input & output conveying capacity of the silo, it may cause dust explosion easily.
Ventilation can be divided into two modes: natural ventilation and mechanical ventilation.
Ventilation system is a necessary supporting equipment in each grain steel silo, the function of ventilation system is to exchange the air inside and outside the silo, to keep the balance of temperature and moisture content of grains and ensure the stability environment inside the grain silo to prevent mildew. The purpose of ventilation system is to create a low temperature of the grain storage environment, improve the grain storage ability, to prevent the transfer of cool and moisture content, expel bad smell from grain and disperse the air after fumigation. This can prevent pest occurrence and spread, also take precautions against dust and explosion.
There is an axial-flow fan on the top of the silo to expel hot and humid air. This can not only not only speeds up directional flow of air in silo, but also prevents condensation phenomenon aroused by temperature difference between inside and outside of the silo.
The axial-flow fan can also adjust the top space temperature and dissipate hot and humid in the upper space and the surface of the silo to prevent grain on the upper layer and the surface from affection by high temperature at the same time.
Normally, the ventilation system is composed with three parts: air blower, air channel and galvanized air deflector. The soft ripe is used to connect air blower and air channel to reduce noise. There are also two kinds of deflector: earth cage style and tablet embedded style. The air channel can be installed both outside and inside.
Fumigation type of Grain Steel SiloThe circulation fumigation system can strictly meet the requirement of China GB/T17913-1999 standard, and can reach the ideal effect of pest killing, grain fumigating and so on. The whole system is designed based on the theory of grain storage, the theory of aerodynamic circulation and the theory of chemical control and the application of micro computer control technology.
The development of grain steel silo in China.
Grain steel silo has experienced four stages in China after it is being applied in China.
The trail period of steel silo application start from 1979 and end at 1981. At that time, small steel silos are mainly used as temporary storage silo and transit silo.
The second period is the period of applied technology(1982-1984), the new technology of fabricated steel silo was introduced from the United State, which are mainly used as as raw material processing silo and transit silo in port.
Upgrade period (1983-early 1990s), during this time, a variety of steel silo were introduced to China, on the basis of other silo construction technology, we absorb their advantages and developed our unique technology. steel silo has gotten significant innovation and development.