The filter collects dust from the air vented from the silo.

What do you intend doing with the dust the filter collects ■

Dear Betconmach,

A filter installation on top of a silo requires no collecting hopper underneath.

The silo itself forms the hopper and the filtered cement dust falls back into the silo.

by connecting silos with A-pipes, the incoming pneumatic conveying air from multiple silos can be handled.

For dedicated silos for a certain type of cement, the specific silo needs to have its own filter.

The filter system comprises only the filter assembly itself over an opening in the silo roof and minimizes the investment.

A filter on ground level requires a collecting hopper underneath the filter and a cement dust retrieving system to empty the hopper from time to time.

Multiple silos with various types of cement can be served by that one filter as the collected cement dust is kept apart.

The filter system comprises the filter assembly plus additional piping, hopper and extraction system and increases the investment.

Have a nice day

Teus ■

There could be a number of other reasons to install the filter on ground level. No access to silo top.

Due to lack of maintenance there have be incidents where the filters have landed on the ground very close to the tanker driver from the silo top.

These days in Europe working at height regulations have lead to many companies avoiding working on silo tops as ladders are not favoured any more and stir towers are expensive. I guess ground level filter is always cheaper than stairs.

Advantages probably are safer to work on. No hazard to filter flying off and landing on somebody.

Disadvantages are higher cost. Need to get rid of the filter dust. ■

Originally Posted by Mantoo

I guess ground level filter is always cheaper than stairs.

Except of course that there are other reasons requiring you to get to a silo roof which means that you still need access, unless you want to scaffold all the way up each time you need access. ■

It will be very silly not to have any access to silo top. If you take the filter to ground level then you will be left with a PRV and a level probe on the silo top. Both of them do not require frequent inspections. Ground level testing is also available for both. So under working at height regulations use of ladder can be justified since access required to top is very infrequent. ■

PRV = Pressure relief valve.

Most of them even have vacuum relief in the same valve. ■