Pre-coating for bags and cartridges

• Optimises system performance.
• Prolongs bag life.
• Quick and easy to apply. Neutralises the aggressiveness of dust particles for the filter fabric.
• Reduces friction loss thanks to less compacting of the particles retained.
• Protects bags during technical shutdowns.

The main uses of ICT FILTRATION PRECap are in installations where the dust particles to be retained are highly corrosive. It can also be used in installations with high levels of humidity, neutralising it and helping to keep the bags clean. The processes at which it is aimed include metallurgy, galvanic and cogeneration plants, among others.

Due to its high content of absorbent dust particles, PRECap also has the ability to loosen the pre-coating that habitually forms over any filter bag, resulting in a reduction in friction loss due to less compacting of the particles retained by the bags.
Use of the pre-coating optimises system performance, prolongs bag life, neutralises attacks by dust particles on the filter fabric, reduces friction loss thanks to less compacting of the particles retained and protects bags during technical shutdowns. It is also quick and easy to apply.
The recommended application dose is 25 kg per 100 m² of filtration surface.

Operation
On starting up suction of the gases coming from the emission source, whether an oven, a kiln, a mill or a silo filter, the dust that comes with this gas will not hit the bag, but the pre-coating of PRECap, which will neutralise these dust particles without them affecting the bag.
To achieve maximum efficiency with PRECap in a bag filter, it is also recommended to add the product before every shutdown of the filter installation, which means the PRECap is left on the filter surface fur the time the filter is stopped, absorbing residual humidity from the bags. When the cleaning system is restarted after the shutdown, the PRECap will be expelled from the bags, leaving them free and ready to filter again.
Para conseguir la máxima eficacia de PRECap en un filtro de mangas, es además conveniente añadir el producto antes de cada paro de la instalación filtrante, lo que equivale a dejar el PRECap sobre la superficie de las mangas durante el periodo en que el filtro permanece cerrado, absorbiendo la humedad residual de las mangas. Al activar de nuevo el sistema de limpieza, pasado el periodo de parada, el PRECap será expulsado de las mangas, quedando éstas libres y dispuestas para un nuevo filtrado.

Environmental impact and shipment
As this product is of natural origin, it does not represent any ecological problem for the environment.
With regard to disposal, it is a product often used at the bottom of landfill sites where it prevents the filtration of soluble compounds, where these exist, into the water table.
PRECap can be used “as is” or mixed with soil.
Regarding shipment, PRECap is not a material subject to transport regulations (TPC, ADR, RID/TPF, IMDG, ICAO) or to their stipulations.

• Optimises system performance.
• Prolongs cartridge life.
• Quick and easy to apply.
• Neutralises the aggressiveness of dust particles for the filter fabric.
• Reduces friction loss thanks to less compacting of the particles retained.
• Protects cartridges during technical shutdowns.

DUST COATING W is used for prior treatment of filters used in difficult applications where, because of the type of dust and its features, regenerating filter elements is complicated.

• Some examples of uses include:
• Welding fume extraction.
• Plasma and laser cutting.
• Thermal spraying.

What does Dust Coating W do?
This prior treatment acts as an intermediate layer (pre-coating) between the fibres of the filter media and the dust cakes, stopping the dust particles adhering to or penetrating the filter structure and clogging it.
It acts like a “lubricant” between the dust particles to stop the cake becoming encrusted and to allow proper regeneration of the filter medium.
It also reduces the size of the pores in the filter medium, stopping dust particles passing through them.
Like this DUST COATING W transfers filtration from inside the filter medium to the surface of the pre-treated fibre.

How is Dust Coating W applied?
First of all the suction system is started up with new filters in a dust-free clean air environment (ideal filter velocity: < 60m3/m2/h). The system will adjust to the nominal volume of air and the real friction loss is measured (about 100 Pa).
The pre-coating is then added to the air current (approx. 5-10 g/m² filter area), with the compressed air cleaning system switched off. Friction loss must be controlled and should rise to about 350-800 Pa of nominal air volume, depending on the final operating load permitted for the installation. For suction systems with an uneven, unfavourable air flow distribution, we recommend applying more DUST COATING W to ensure the whole filter surface is properly covered.
The dust can now be fed into the system. The suction system should work without activating compressed air cleaning until a friction loss of about 1,600 Pa is reached.
When compressed air cleaning is started up, make sure it works at the lowest possible pressure. The cleaning system must be set to keep the friction loss above 1,000 Pa at all times. To maintain this level, even with different loads of dust, it is recommended that Delta-P control (cleaning on demand) be used for the cleaning system. If these precautions are followed, you will probably only have to use DUST COATING W to create a pre-coating once during start-up of the system.

What else should be taken into account?
What else should be taken into account?
The following adverse factors should be borne in mind:

• Excessively high air/fabric rations.
• Poor hopper/container design.
• Uneven distribution of cleaning power, which can cause higher friction loss, but can be compensated by creating another pre-coating after a certain operating time.
• Compressed air cleaning while the system is stopped (cleaning while shut down).