There is a new product that using ultrasonic vibration to reduce the wall friction sufficiently to induce flow. The down side is its noise. If noise is an issue, it may be possible to design a barrier to contain it.

You may get a solution from researching the paper:

http://ieeexplore.ieee.org/Xplore/lo...495.pdf?temp=x

We postulated this principle years ago and began an investigation into the concept. Then life got very busy.

This paper is dated 2003. There is a recent web posting on its effectiveness and a test lab video with the appropriate noise level. It is pretty loud. I would have to research it to find the advert. Maybe the developers will come forward. ■

Hi sinclas,

Have you considered the Cardox system to remove the build up, I recomend you look at www.Cardox.co.uk the original manufacturers of the Cardox System ■

I received that miniature flow pattern modeler from a famous consultant. It was a superb perspex model with one side of the egg timer giving core flow & its mate on t'other side giving mass flow. Beautifully made & a treasured desk decoration. Powder sticks to either surface & can be dislodged with a tap, as in your case. If it can happen to them what chance for the rest of us.

I would introduce a more sophisticated cleaning device. Three rubber mallets equispaced around the hopper & suspended from/attached by decorative chain will clearly do the job. you'll have to do some extensive search because B & Q don't advertise on the forums. ■

Sorry, I forgot to mention Wilkinson's!■

Originally Posted by sinclasc

Hello,

I have a build up of fines (PVC blend) on the walls of my internal silos. This build up is approx 3 cm thick and soft & powdery - not feeling at all damp. it is dislodged very easily, such as a bang or walking on the silo roof (!).

Has anyone experienced similar, and if so what measures can be taken to reduce?

I would almost guarantee a tank washing nozzle used with carbon dioxide or nutrogen gas from spraying systems inc would dislodge the fines clinging to the silo walls buuuuuuuuut-

The risk of explosion from free dust in the atmosphere would worrry me much more. please look the threads regarding dust explosions on the forum.

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How well grounded is the silo? Do you have multiple copper leads to steel rods driven into the ground or grounding connected to the building foundation and steel work rebar in the foundation?

An immediate fix for your problem comes to mind, the use of a telescoping loading chute would reduce dust build up on the walls by containing the pvc particles close to the center of the silo.

The telescoping loading chute would raise and lower according to the amount of material delvered to the silo using paddle switches/tilt switches to detect the material level and raise the tube until it is stopped at the desired height.

The level control is tied in the electric power for the blower and when the tube is fully retracted or retracted to the point desired in the silo it would shut the blower off during delivery to the silo

The chute could be set for a given distance of vertical travel and in turn reduce the amount of friction related dust floating in the silo.

A telescoping chute provider would be your first contact regarding this as the pvc dust is lethal like so many other dusts created in industry.

lzaharis ■