Features of ferrofluid seal:
1. It can seal gas, water, oil, dust, smoke, etc.
2. No leakage
3. Perfect sealing performance no matter what's the speed of shaft. From static to low speed and high speed, all the same
4. No friction, loose requirements on shaft runout, eccentricity and surface finish; Durable
5. Ferrofluid seal is non-directional, instantaneous overpressure, when the pressure is restored, ferrofluid can be automatically reset
6. The system is simple, and it has a lubricating effect while sealing
Scope of application of ferrofluid seal:
1. The sealed medium should be gas, liquid or dust. If the medium is in a solid state or a solid-liquid mixed state, the "O" ring will be destroyed, making the seal ineffective
2. The working temperature of ferrofluid will be better between -20 ℃ ~ 120 ℃. If the temperature is too low, the carrier liquid may solidify; if the temperature is too high, the magnetic power weakens or even disappears, and the liquid quickly volatilizes, destroying its stability
Used for elaboration, especially for super hard materials. The method is to mix abrasives with a particle size of several micrometers to hundreds of micrometers in water or oil-based ferrofluid, and the magnetism is used to force the abrasive to grind the surface of the workpiece. Since the workpiece can rotate itself during the grinding process, it can be ground at the same time whether the processing surface is flat or curved. Compared with the usual methods, its efficiency is increased by 15 times
It is required to increase the dynamic range and maximum sound pressure level of the speaker in order to meet the high-level needs of the audio system. Therefore the input power of the speaker must be increased, but it will cause the temperature rising of the voice coil. When the allowable value is exceeded, the voice coil will cause thermal damage.
Solution: Inject magnetic liquid around the voice coil in the air gap of the speaker.
Function: Improve the heat dissipation and increase the power of the speaker. Improve magnetic flux density, increase sensitivity, reduce distortionand reduce magnet size.
Rotation of propeller is one of the main sources of submarine noise. Substituting ferrofluid propeller for propeller can reduce submarine noise to the greatest extent.
The outer shell of the thruster is made of titanium alloy, and the inner wall is equipped with a rubber sleeve with high elasticity and high toughness. The rubber sleeve is filled with ferrofluid with saturated magnetization, and a group of ring-shaped excitation coils are arranged outside the rubber sleeve. When energized, the coil forms a pulsed magnetic field, and the magnetic fluid generates a traveling wave under the action of the pulse field, which causes the inner wall of the rubber sleeve to "creep" continuously, forcing seawater to be sucked from the front of the sleeve and accelerated, then ejected from the rear end at high speed
Bionic damper: Ferrofluid and smooth elastic rubber compose to the bionic drag reduction and noise reduction coating layer which is coated on the surface of the submarine
The medicine is mixed with ferrofluid to make an emulsion and injected into blood. Under the traction of external magnetic field, the emulsion is transferred to the site of the focus of infection for treatment
Ferrofluid is used as a contrast agent for gastrointestinal X-ray contrast, and then the gastrointestinal examination is performed by external magnetic field
Remove special cells in blood: chemically treat the blood to make the biological cells adhere to the ultra-fine magnetic particles and magnetize the red blood cells. Then the red blood cells are separated under the action of a strong magnetic field gradient to remove the special cells
Separation by specific gravity method: Put two non-magnetic, different density materials which need to be separated into ferrofluid. When the density of the ferrofluid is the average of above two substances under the action of the external magnetic field, one substance sinks and the other floats to achieve the purpose of separation and recovery.