Stainless steel filter elements are essential component for the filter equipment of some vacuum conveying systems, and good substitute for non-metallic filter elements used in most vacuum conveying applications.
Vacuum conveying is the process using air pressure to take the solids, usually powder, granule or other small particles, to the downstream processing equipment. Vacuum conveyor is also called pneumatic conveyor in powder handling industry.
The tank, bin, silo and pipe in the streamline of the vacuum conveying system are subject to passive pressure for the motivation of the air and powders. So the possible leakage of the system will cause inward contamination. As the suction of pump continuing to form passive pressure, there is need of filters to stop the powders from escaping the system to the atmosphere.
Stainless steel pleated filters for vacuum pump
The pleated filter cartridges have more filtration area than filter bag and filter tubes. They can hold more dirt and have longer service life.
The pleated filters remove the dust or powder from the pump air flow. The filters keep the pump from unwanted particles entry and stop the powders from jamming and escaping.
The stainless steel pleated filter features:
- Suitable for micron range particles:
- wire mesh for 1 micron nominal,
- sintered metal fiber felt for 3 micron absolute.
- High temperature resistance to 500 degree C
- Anti-static as stainless steel parts are conductive
- Suitable for sterilization in food or pharmaceutical applications
- Washable and reusable
Sintered mesh filter elements to substitute the filter bags
Filter bags for the filter or dedusting house are light weight and relatively cheap. However, filter bags can only filtrate from inside to outside without the filter cage, and they are often not washable and can not be reused.
There is also risk that the synthetic fibers on the filter bag shed and fall off then contaminate the powder conveyed. It may not be accepted in critical applications like pharmaceutical products. The synthetic material and powders accumulated on the filter media will be another problem when disposing the used filter bags.
Sintered mesh filter elements can solve all these problems filter bags may have. Whether originally designed or later modified the sintered mesh filter elements is convenient to use as the multi-layer sintered wire mesh is self-supported and easy formed with good weldability.
Sintered mesh filter elements features:
- Flow direction flexible (outside-to-inside or reversed, only changing the fine mesh side)
- Up to 1 micron nominal filter rating
- High temperature / pressure working
- No material migration or shedding
- Anti-static
- Washable & reusable, suitable for sterilization
- Recyclable and no headache of disposing
Sintered mesh filter elements with quick mount ferrule adapters ( tri-clamp pipe fitting ):
Sintered metal filter fluidizing device for silo discharge
Powders or granules may often accumulate or bridge at the silo outlet. So there is usually vibrating or fluidizing methods to avoid jamming and bridging and help to discharge.
One solution is making a filter cone according to the shape of the silo hopper. This sintered metal / mesh cone will be the fluidizing bed.
Another solution is making filter sparger or similar element and installing several on the hopper. The spargers are then pumped with compress air and the distributed air will stir and motivate the powders. These sintered metal filters can be made of whether sintered metal powder or sinterd wire mesh.
Summary
Stainless steel filter elements are good choice and sometimes the must-have for certain vacuum conveying system.
They are anti-static, washable, suitable for sterilization, reusable and recyclable, resistant to high pressure and temperature, and without risk of filter media shedding.
They can be used as pleated filter for pump, sintered mesh filter to replace filter bag, or fluidizing bed device for material discharge.
Although the stainless steel filter elements is more expensive than most of the non-metallic filters, the overall outcome lead by the convenience of cleaning, re-usage and recycling is considerable. The life time increased and shutdown time reduced should also be considered.