The role and risk of ion fans
1, ionic static eliminator in addition to the principle of static electricity: the generation of air ions, acting on the static power supply and static electricity.
2. Ways to enable air ionization: A. Air corona ionization under strong electric field conditions produces positive and negative ions; B, A-ray and β-ray action air molecules make it an air ion; C, high-energy ray (X-ray) Air separation ionization;
Air ion characteristics
1. Air ions are different from solution ions, which require a certain amount of energy to be generated, and usually exist in the form of molecular groups;
2. Air ions are also present in the natural environment, but the concentration is very low;
3. The life of air ions in clean air is between a few seconds and a few minutes;
4. When positive and negative ions come together, they will neutralize each other;
Several problems to be considered in the use of ionic static eliminators
1. The working distance considers two factors: A. The closer the distance is, the faster the static electricity is eliminated; B. The different types of ion static eliminators have different effective distances.
2. Ion static eliminator of strong electric field ionization mode The discharge needle is the most aging and damaged component. Regular cleaning and maintenance can ensure the equipment is effective.
3, eliminate the static speed: consider the index - dissipation speed, generally use CPM to measure its dissipation speed of 1000V-100V;
4. Ion balance: Ion imbalance will cause objects in the area of action to carry the surface turtle, so it must be controlled. Ion imbalance occurs only in corona ionization ionization equipment;
5, other considerations: different types of ionization equipment for different objects
Various types of ion fans
1. AC ion fan:
A, simple design and low cost;
B, stable
C. The sine wave has low ionization efficiency and is not suitable for occasions requiring rapid neutralization;
D. Different positive page ionization energy makes ionization balance work difficult;
E. Positive and negative ions alternately produce a natural neutralization of ions with a period of 1/100 or 1/120 second (50 or 60 Hz), which further reduces efficiency.
High wind compensation is required;
F, due to low efficiency, the need for a larger voltage to generate enough ions, will cause a lot of particles, is not conducive to a strict dust-free environment.
2, DC ion fan
A. Continuous high pressure uses high ionization efficiency and can handle rapid neutralization needs;
B, can use a lower voltage, suitable for clean room use;
C. Ability to use automatic measurement and feedback to control ionization balance;
D. Complex control circuits are needed to ensure the balance of positive and negative ions.
3, pulsed DC ion fan
A. The ion population generated by the pulse reduces the natural neutralization. Allow the ionizer to leave the protected object farther (can pass 5 meters);
B. It is most commonly used in dust-free workshops where low air flow may be required;
C, the pulse time can be adjusted to suit the airflow or distance requirements of the environment;
D, the pulse wave triggers a "voltage swing" voltage change, which may be detrimental to some devices.
4, high frequency AC ion fan
A, 3000HZ or higher frequency AC mode can greatly improve the AC ionization efficiency;
B, a lower ionization voltage can be used;
C, good ion balance;
D, the discharge needle does not need to be grouped, the size can be made very small
E, suitable for use in clean room
F, short acting distance, wind compensation.