Pneumatic activation of bulk materials with Matakt air blast devices

Bulk solids must flow to convey materials from A to B. Bridging in silos or hoppers, or blockages and coating in pipelines however would be counterproductive. It often impacts the functions of process plants, which results in expensive losses of production and additional costs to make the material flow again.

The B+W Gesellschaft für Innovative Produkte has developed its Matakt Air Blast Devices - also known as Air Cannons – in particular to solve these problems. A wide range of components for individual applications is available. The specialty supplier from Bottrop in North Rhine-Westphalia offers a turnkey system that comprises pressure vessels with quick-action stop valve, control unit with safety devices as well as various outlet nozzles, including assembly.

To eliminate the malfunction, compressed air tanks are mounted at the outside of the hopper, bunker or silo walls. In the vicinity of the low-flow zones, holes with a diameter of approx. 80 mm are provided in the walls. Pressure vessel and blow-out nozzle (mounted inside the silo) are then connected by a 2 1/2” hose. Due to this large pipe cross-section, it only takes milliseconds for the blow-out head to blow the stored air energy into the critical material zones. The air volume blasts off the clogged material, so that it can flow again conveyed by the flow of gravity. A 1/2” compressed air line as well as a collecting cable for the control of the valves are laid to the air cannon. The launch valves at the pressure vessels are activated by the control unit, which is also equipped with all safety and air pressure maintenance devices. Control may occur manually, by means of a push button, fully automatically or via error signals.

Silo with flat bottoms

A perfect system to ensure a smooth discharge at the underfloors and to make the material flow again are “the specially developed 45° lance nozzles mounted on the flat bottom of the stockpile discharge,” Georg Buddenkotte, the sales manager, points to an innovative detailed solution. This intelligent process simulates the 45-degree cone angle at the flat bottom, which often occurs in silos. In case of flat bottoms with underfloor discharges, this considerably increases the discharge capacity.

Diversity for maximum efficiency

The Matakt system (short for Material-Aktivierung, i.e. material activation) of the air blast devices from B+W is designed to eliminate problem areas specifically according to their occurrence. Pressure vessel variants with sizes of 36 to 100 l are used along with blow-off valves arranged at the vessel in different numbers and positions. They develop their full capacity already at only 8 bar. With their individual position and mounting direction, the air blast devices flexibly adapt to the space available, even under confined space conditions. Besides the 45-degree lance nozzle, the lance nozzles, angle nozzles and spreader nozzles ensure that the air blast is discharged exactly in such a way that it solves the problem in the specific material flow and makes the bulk material flow again.

In case of the lance nozzle, the air escapes laterally from the nozzle with the speed of sound, forms an air wedge, which separates the adhering material from the vessel wall and causes e.g. bridging to collapse. In case of the angle nozzle, the air flows out at the front of the nozzle driving the material in flow direction. The spreader nozzle demonstrates its qualities in particular with loose materials (such as sawdust). Similar to an air fan, the air jet acts as a “large, sliding wall” for the material to be activated.

Thus, the material activation system Matakt proves to be an ideal assistant in many cases of material flow problems with bulk solids.

Stand: A 24 - 4