Bag filters for high temperatures – DUSTdown^® High Temperature

DUSTdown® High Temperature is an extremely high-efficiency, self-cleaning filter with an online automatic cleaning system, which uses compressed air jets in Reverse Jet mode. This bag filter has been designed by Tecnosida® to face the specific problems related to the treatment of emissions deriving from:

•  solid biomass combustion (woodchips, wood, pellets, brushwood, agricultural waste, rice husks, sunflower shells…);
• fumes from furnaces;
• high temperature fumes with acid gases

The inlet of the air to be treated is located in the lower part of the dust collector. The flow passes through a pre-abatement chamber to allow the coarser dust to precipitate, thus protecting the filter from excessive dust loads. After this first phase, the flow passes through the filtering elements; the result is the 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 it to the collection or transport systems. These systems can be of different types depending on the needs of the production sector: collector, star valve, clapet valve or channel/ducted screw, or a pneumatic conveying system.
The filtering fabric is kept perfectly efficient thanks to automatic cleaning cycles, managed on the basis of the pressure drop reading. This manufacturing solution ensures a limited consumption of compressed air and a longer lifetime of the bags.

Extremely important: emissions deriving from the combustion of solid biomass are characterised by a high level of acidity which, over time, leads to the corrosion of the metal parts of the filter. For this reason, our DUSTdown® High Temperature filters are equipped with an automated injection system of basic substances (lime, bicarbonate or other substances) that abate the acidic component of the fumes, thus preserving the internal structure of the bag filter and its operation.

The presence of acidic substances and water vapour implies the possible development of acidic condensation, which must be avoided even during start-ups and shutdowns by means of appropriate technologies.

The DUSTdown® High Temperature bag filter:

• is manufactured and configured according to the specific use in your business, taking into consideration flow volume, temperature, quantity of dust and size of its particles;
• is designed to achieve very high levels of efficiency: even more than 99.9% of dust is removed;
• involves the use of specific construction materials in relation to the emissions to be treated. In addition, Tecnosida® adopts special, very high-quality filter media for continuous use up to maximum flow temperatures of 250°C;
• is insulated externally in order to allow controlling the condensation effect due to the high temperature range between the water-saturated fumes and the walls of the bag filter (which may be at room temperature);
• does not present any particular level of complexity and it is tested, reliable and cost-effective;
• can be designed with proper dimensions for both limited and very high flow rates, as it is fully scalable and modular. This provides a greater flexibility in design, transport and installation on site;
• various discharging systems can be provided in combination with the hopper: manual, automatic or customised;
• the ladder and railings offer easy access to the filter roof for the replacement and maintenance of the filtering elements.

The DUSTdown High Temperature bag filter can be used in the processes that cause the emission of high temperature dust and fumes. They include:

• biomass combustion plants and biomass boilers;
• operations where furnaces and kilns are used (glass industry, metalworking industry and the like);
• food industry;
• waste incineration and the like.

• Filtration chamber;
• Hopper with collectors and support legs;
• Inspection door/s in the hopper;
• Pneumatic cleaning system of the bags controlled by a differential pressure switch or economiser;
• Settling or pre-abatement chamber;
• Ladder and railings for extracting the filtering elements from the roof;
• Specific insulation made up of rock wool and aluminium sheet finishing.

• Pressure regulator;
• Economiser;
• Anti-fire systems.

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!
Contact Tecnosida for specific advice tailored to the technical situation of your company!