Self-cleaning bag filters – DUSTdown^®

DUSTdown® self-cleaning bag filters separates the solid particles in suspension from the air flow to be treated through the use of a physical filtering element. It is a self-cleaning filter, i.e. it is equipped with a system which is capable of removing the dust deposited on the filtering bags periodically. The use of this type of technology makes it possible to treat fine and ultrafine dust, thus achieving very high filtration efficiency levels.

The inlet of the air to be treated is located in the lower part of the dust collector; the air is conveyed into the self-cleaning bag filters by means of an extraction system. It passes through a pre-abatement chamber to allow the coarser dust to precipitate, thus protecting the filtering bags from excessive dust loads. Then the flow reaches the filtering surface and passes through it; the result is the suspended particulate separation. Dust is retained on the outside of the bags and it is then precipitated into the lower part of the filter where the hopper conveys (or the hoppers convey) it to the collection (or transport) systems.
These systems can be of different types depending on the needs of the production sector for which the filter is intended: collector, star valve, clapet valve or channel/ducted screw. The filtering fabric is kept perfectly efficient thanks to automatic reverse jet cleaning cycles.

These are managed on the basis of the pressure drop reading so as to ensure limited compressed air consumption (see the graph on the right) and a longer lifetime of the bags.
Filtering fabrics can also be made up of different materials with different characteristics depending on the intended use. The following table outlines the main variables:

Depending on the characteristics of the production process and on the dust that is present, the DUSTdown® bag filter can also be manufactured in the following versions:

• ATEX: DUSTdown® ATEX bag filters are used for flammable and explosive dust and for areas at risk of fire;
• High Temperature: DUSTdown® High Temperature filters are used in the presence of high temperature air flows.

• it is manufactured and configured according to the specific use in your business, taking into consideration quantity of dust and size of its particles, temperature and volumetric flow rate;
• it can be designed to achieve very high levels of efficiency: even more than 99.9% of dust can be removed;
• it allows the separated solid residue to be reused;
• it does not present any particular level of complexity and it is tested, reliable and cost-effective;
• it can be designed with proper dimensions for both limited and very high flow rates, as it is fully scalable and modular;
• it is suitable for ATEX certification, if dusts classified as explosive or flammable are to be handled;
• various possible discharge systems (manual, automatic or customised) can be provided in combination with the hopper;
• it is equipped with a ladder and railings which offer easy access to the self-cleaning bag filters roof for the replacement and maintenance of the filtering elements.

Over the years, we have developed bag filters for the filtration of fine and ultrafine dust in different contexts. They include:

• processing of special metals in Poland;
• grinding and recovery of disused household appliances;
• production of chemical agents;
• production of adhesives and detergents;
• herbicide production;
• paint production.

• filtration chamber;
• filtering bags;
• hopper with collectors and support legs;
• inspection door/s in the hopper;
• pneumatic cleaning system of the bags controlled by a differential pressure switch;
• settling or pre-abatement chamber;
• ladder and railings for extracting the filtering elements from the roof;
• triboelectric probe (mandatory in some regulatory areas).

• pressure regulator;
• economiser;
• anti-fire systems;
• moto-vibrators;
• bridge-breaker cannons;
• insulation

Tecnosida® also plans regular ordinary and extraordinary maintenance. This service is also available for DUSTdown® High Temperature and it ensures:

• proper functioning of the filter;
• high pollutant filtration efficiency;
• waste reduction (both in economic and energy terms)

For further information, do not hesitate to contact us: we will plan this important activity with you!