GRUPA WOLFF has designed a system for a leading producer of healthy food and functional food as intended for extracting the dusts generated in the pneumatic transport process of wheat, barley, rice, maize grits, bran and flour (of wheat, corn, or rice).
The delivered dust extracting unit was based on relatively small, screwed together steel panels. The solution allowed to reduce production, transport and assembly costs as compared with conventional devices with welded structure.
Dust from the filter will be collected by means of a chamber dispenser whose task is to close the dust tank operated at a pressure different from the atmospheric one and to enable emptying the tank without decompression. In accordance with the design input, the dust will be unloaded to „big bag” type bags. The chamber dispenser also acts as a passive barrier in the event of a dust/air atmosphere explosion (it stops the flame wave and is resistant to the impact of reduced explosion pressure, which is of great importance for the safety of dust extracting systems intended for explosive dusts).
In order to secure the filter unit, a system has been applied for venting the explosion through decompression panels. In accordance with the design input, the unloading panel is equipped with a pressure relief channel aimed at bringing explosion effects to the outside of the building. In addition, on the dirty air duct, a return flap has been installed that functions as an explosion decoupler, just as a cell valve.
In this construction, a unit with filtration surface of 75.2 sq. m has been applied. The dust extracting system operation is based on aspiration of air through a fan, which generates a vacuum enabling suction of air/dust mixture from the hood installed over the mixer hopper. Next, the dust-laden air flows into the dust collector and expands; as a result, larger fractions of dust are precipitated and they fall by gravity to the bottom of the hopper. Subsequently, the air flows through the filter material of cassettes to the so called clean chamber. When the intake air flows through the filter medium, fine dust particles are separated from the air.
During the filtration process, the dust deposited in filter pleats is periodically shaken off by short pulses of compressed air generated by a pulse solenoid valve actuated by a controller. The air blast is strong enough to knock out dust particles from the surface of the filter and to make them fall to the bottom of the hopper. A properly operated regeneration system ensures a longer service life of filters without having to replace them frequently.
The tasks performed by GRUPA WOLFF included::
- preparation of an execution design of the aspiration system as based on the conceptual design,
- delivery of the dust extracting system along with the control system,
- erection of the whole installation, from small structures for supporting and suspending the installation through the filter unit and explosion protections,
- safety measures at dust removal system tests.
SCOPE OF WORK: design, supply and erection of a dust extracting system for a manufacturer of functional foods
LOCATION: Poland, Mazovia Province