SILO TOP FILTER
This type Filtres used to vent silos, hoppers, mixers into which material is conveyed. As the material fills the silo, hopper and mixers, it displaces air, which must be vented without loss of product. Product collected on the filter bags is returned to the silo by pulse jet the bags after filling has been completed.
Hopper, Mixer, Silo Venting Filter available in two series:
Natural Vented, where a low positive silo pressure is acceptable.
Blower Assisted, where a negative silo pressure is desirable.
Displaced air from the silo filling operation is filtered through the bags the bags must be cleaned by compressed air.
Why do I need a dust collector filter on top of my silo?
Approximately for one truck unloading procceses 20 kg (or more) of dust are exhausted into the atmosphere. A properly sized dust collector will capture this dust and return it to the silo.
How do I size the dust collector filter for my silo pneumatic filling operation?
When designing a dust collector for a silo, the following information is required: fill line pipe size; quantity of pipe lines filling at one time; air flow and pressure; loading time and material which handled. Most applications use a single 4" or 5" diameter fill line running at 350 cfm @ 12-15 PSI for approximately 45 minutes. The material handled is either cement, flyash, or sand.
I just overfilled my silo. Have I damaged the dust collector filter bags?
If you have just overfilled silo, inspect the dust collector before you do anything else. Open the door and see if the bags have been damaged or are full of product. If the bags have a lot of dust in them, but are not ballooning out, shake each bag down by hand until all the dust is removed. If you are lucky, the bags will be OK. If the bags have ballooned out, or if some of the bags have come off the tubesheet, replace all of them. Once the bags are stretched out, the weave in the bag loosens, allowing dust to pass through.
How do I prevent overfilling my silo to not damaged to filter?
TeknoFilter has a complete series of overfill control systems for all silo filling operations.
Do I need a pressure safety valve?
Whenever a silo is being filled by a pneumatic offloading system high pressure is forcing material into the silo. The pressure safety valve, or "pop-off valve" will allow the pressure to escape preventing any additional damage.
Do I need a fan on my silo dust venting filter when I pneumatically load the silo?
Normal operation with a good sealed silo, a fan is not requested. If the silo is totally sealed, the air from the filling operation can only go in one direction through the dust filtersr. If the dust filterr is small, or not fixed properly, the pressure safety valve will be open. But if the dust filter is sized properly, a fan is not needed. However, if the silo has holes in it, or is being fed by a screw conveyor, bucket elevator, or air slide then you will need a fan to keep negative pressure in the silo.
I have a lot of moisture in my silo feeding operation. Is there a better bag type available?
For high humidity or high moisture applications you should use siliconized dacron bag. This material feels like a silk shirt.
I have a one more compartment silo. Can I use one dust collector?
You can use a single fan assisted dust filter. You also need to install inter- vent ductwork between the two compartments. This ductwork is twice the diameter of the fill pipe and designed like an inverted "V" with a minimum 45º angle to allow the dust to fall back into the silo. You can also use this approach if you have two silos. Remember to always put the dust filter at the highest point on the silo. If handling cement and flyash, put the collector on the fly ash silo. If both silos are being filled at the same time, be sure to provide a collector to handle both silos.
I am loading from a rail car. What type dust collector do I use?
Generally you would use a jet pulse filter, continuous cleaning dust collector. On occasion, when compressed air is not available, you may be able to use the mechanical shaker collector. This collector allows one compartment to shut down and shake while the other side is on-line