Airsweep system

System Airsweep®

On the basis of American Airsweep® technology, we offer high-tech solution to problems with bulk granular material’s flow. We kindly invite you to take advantage of our partners’ experience. We have been creating professional systems for silos and containers for more than 40 years.

Problems with a proper flow of bulk granular material could occur in every place where those materials are processed, stored and transported.

Let’s take a close look at the basic mechanisms of material flow in containers and silos; furthermore, let’s get acquainted with problems that could occur and methods of solving them.

fig. 1
Volumetric flow

fig. 2
Flow over the central tunnel

fig. 3
Formation of the central tunnel

fig. 4
Formation of the "cupola"

fig. 5
Material segregation

With regard to forces that operate in the container; depending on material properties, container’s shape and other factors, there are several different mechanisms of the flow and several different ways of force deployment. In practice, we pay our attention to two basic mechanisms of a flow when emptying a container:

- volumetric flow: after opening a container, material’s layers are translocating in sequence in the direction of the exit. The sequence is the same as the one which was kept with pouring in (fig. 1); this type of flow is typical for the containers with relatively plain walls that have angle of depression between 15° and 25°

- central flow: it occurs when silo’s walls are less plain, and their angle of depression in lower part is larger – it increases friction force that affects walls; layer that is poured in as the first, leaves silo as the last, flow is mainly conducted in the central part of the container (fig. 2).

The central flow causes a formation of so-called “still zones”; in other words, these are layers of material that do not translocate when emptying silo, till the time when level in container is the same height. Sometimes it is only possible after complete emptying of the container. "Still zones" lead to formation of so-called „central tunnels” (fig. 3) and "cupolas" (fig. 4)). The situation introduced in fig. 4 is caused by translocation of material weight on the container’s walls, instead of translocating it to its lower parts. Material flow could be completely blocked.

Those situations often lead to container’s damage (when material is finally torn off the wall). Long retention of material in many situations affects material’s quality (makes it worse) and causes trouble in the technological process.

The additional problem that could frequently occur is material segregation (fig. 5). Unless material is homogenous; when central filling, there are situations when the material of a bigger fraction is moving in the direction of silo repeatedly. The smaller fraction, which is situated in the central part, leaves container in the first place. This is very unfavorable occurrence; especially, if we are dealing with a product or raw material that is intended for selling. In that case, its uniformity is an essential factor.

One of the possible solutions could be designing a bonde that is big enough. Unfortunately, in most silos and containers, which are used in industry nowadays; this solution is not applied.

Lack of appropriate solution contributes to using the least effective methods, as for example mechanical hit in a silo or pipeline. The results of those actions could be seen in the pictures:

The technology of pneumatic nozzles that operate in sequentially pulse bursts of high velocity air - Airsweep® is a proven and effective solution to improper flow of loose material’s problems. Airsweep® nozzles’ system is based on sequentially pulse bursts of high velocity air. It joins strength of compressed air and controlled dosage together. Hence, “still zones”, as well as material that is set on inner walls of container, are removed.

The usage of compressed air is far lesser than in the case of air pads, pneumatic vibrators and the like. Nozzles produce short impulses of compressed air along container’s wall or other system’s wall. Thanks to high speed of air stream, VA-51 nozzles are able to remove remaining material within a radius of 2400mm with every impulse. The essential things here are appropriate air-pressure and stable power supply. We cordially invite any interested person to fill in the on-line form or to wypełnienia formularza on-line lub contact us to create detailed offer that will be adapted to technical conditions, type of material and occurred problems.

Airsweep® nozzles’ operation is controlled by the electronic sequence controller. Prior settlement of impulses distribution in the particular areas is essential. This must be done in accordance with used technology and physical features of transported material. Obviously, potential increase of time intervals between impulses enables to lower the costs of the system. In 98% of cases we are able to provide you with completely smooth flow of loose material in the particular technology.

Airsweep® system’s features:

- it is not possible to clog or block a nozzle thanks to short impulse’s time (0,25 second), as well as thanks to specially designed spring mechanism that removes possible particles that could occur in the part of a nozzle where loose material is present
- insignificant consumption of compressed air and energy
- quiet functioning – when using silencer next to exhaust opening of valve
- no vibrations or shake of a silo’s construction
- the system does not require conservation or service
- it operates with wet, damp and loose material
- max. temperature 500°C
- installation is conducted from the external container’s wall
- high level of effectiveness – one impulse moves material’s layer within a radius of max. 2400 mm (depending on bulk material’s features)

Our devices are used in the following branches:

- power industry,
- building material production,
- chemical industry,
- metallurgical industry,
- food industry,
- pharmaceutical industry,
- ore processing,
- mining industry,
- glass industry,
- agriculture,
- other