®
glosfume and dry scrubbing – a perfect partnership
®
glosfume
The disadvantages of using lime or sodiumbicarbonate with bag filters
®
Advantages of using sodiumbicarbonate with glosfume filters
®
glosfume
In conjunction with our proven high temperature particulate filtration,
powder injection
systems can be combined with sodium bicarbonate and activated carbon for dry scrubbing to
neutralise acid gases such as HCl, HF, SO and dioxins.
2
For efficient removal of acid gas with lime, bag filters need to be operating in the narrow
100–130
°C range within which the lime remains stable. Above this temperature range
consumption increases and efficiency falls.
Another disadvantage of bag filters is that they can only operate with sodium bicarbonate at
temperatures of 140–260°C. Because the upper end of this range is close to the ignition point of
the media, there is a considerable risk of filter bag fires.
Finally, because bag filters operate at much lower face velocities they require the addition of costly
reaction towers to achieve efficient dry scrubbing.
By using
filters these problems can be avoided.
Sodium bicarbonate stays fully active, with no variation in consumption, between 140°C and
450
°C. For optimum efficiency and the fullest use of the available sodium bicarbonate, each
complete filter is carefully modelled using computational fluid dynamics (CFD) to reveal the even
pattern of particulate stopping positions. CFD design also helps ensure that pollutants are
uniformly presented to the whole filter element, and that all the absorbent is drawn onto the
elements where the reaction takes place.
High Temperature Air Filtration
Injection point of absorbent
A one-tonne big bag feeder injects absorbent
7
