I am currently conveying a mineral material through a pneumatic conveying system using nitrogen. Size of the material is 3/8 x 20 mesh with approx 5 % running below a 20 mesh screen. This material when unloading from a tanker truck must travel through approx 100 feet of 4 inch pipe( horizontal blow ) into a holding tank. When this product is used it is then conveyed vertically approx 300 ft to another set of holding tanks( 4 inch pipe). This product contains both hard and soft aggregate.

My problem : 90 % of the time the conveying of this material runs smooth the other10% of the time I get plugging issues which causes expensive downtime.

Some of the questions I have

Could there be separation of particles from using either too much pressure or not enough pressure. Could the hard particles be breaking down the softer particles creating to many fines which would cause plugging. Approx density of this material is 74 lbs per cubic ft. Any help would be much appreciated ■