Atomizers for flue gas cleaning (FGC)
Spray
dryers with rotary atomizers are used in semi-drying processes for
cleaning of flue gases from heat and power generating plants (SO2
removal), biofuel boilers and waste incinerators (acid gases and
dioxins removal).
Besides, guaranteeing a high efficiency, drying
processes are particularly advantageous because polluted materials
can be reduced to dry powders at limited operating costs.
The
flue gas cleaning is a very severe application for the atomizer,
where a combination of corrosive and abrasive ambient require that is
expressly designed in order to meet the demand of high reliability,
long running operation time, high efficiency and long life time.
CMT
Atomizer features:
- Heavy duty design
- Capacity up to 30 tons/h in feed rate
- Simple construction that allows low and easy maintenance
- Parts
in contact with corrosive ambient, manufactured in special alloys (
C276 – C2000) or Titanium
- Spiral feed distributor to
eliminate problem of clogging, deposits and vibrations
- Special
wheels wear-resistant design against abrasion with interchangeable
inserts and wear plates in advanced ceramics
- Additional feed
pipe for quench water that allows fast control of flue gas
temperature and emissions, besides prevents scaling
- Atomizer
jacket with accoshield covering PTFE for protection against corrosion
with non-stick properties
- Continuously run time in operation
over 2000/h
- Bearings replacement >12.000 working hours
- Easy exchangeable with spare atomizer for routine maintenance (
approx. 15 minutes)
- Monitoring of main functions of atomizer:
- Lubrication
cycles
- Bearings
temperatures
- Vibrations
- Rpm
- Operation time
- Durable life span over 30 year
CMT Reverse Taper Nozzles
The standard atomizer nozzle geometry is designed that the inlet diameter of the nozzle is greater than the diameter of the outlet nozzle like a funnel. With the Reverse Taper Nozzle this is reversed; the inlet is a smaller diameter than the outlet diameter of the nozzle.
The slurry from a standard nozzle is more shaped like a stream spray pattern. The slurry pattern from the Reverse Taper Nozzle is shaped more like a fanned spray pattern. The thickness from left to right of the slurry exiting the Reverse Taper Nozzle is much thinner.
This results in greater surface area :
- Increases overall wear life of nozzle
- Creates a more uniform spray pattern for a longer period of time
- Reduces the chance of wetting the dryer walls
- Successfully tested in So2 removal applications and waste incineration plants where slurry of lime milk are required
Long term operations from multiple sets of nozzles have resulted an average of 10% reduction of lime usage and a 2-1/2 times longer nozzle wear life.