Trona and Sodium Bi-Carb
Sturtevant Powderizer Air Classifier Mill and Simpactor Pin Mill

Coal Fired Electrical Power Plants: Many aging U.S. Coal fired power plants are looking at the Sodium Carbonate family of minerals to help neutralize So2 or So3 (SOx) emissions to the atmosphere. Specifically FGD, using a dry injection system with fine Trona (Sodium Sesquicarbonate) or Sodium Bicarbonate as a medium has proven to be a valuable option to using a wet lime system for small to medium vintage plants of 100 to 750 megawatt.

The cost to fit an older plant with a dry mill and injection system involves much less capitol outlay to meet new regulations than an expensive wet scrubbing system. This is important since the life of an older plant will not be long enough to support the R.O.I. for a capitol intensive solution. Dry systems, (using Trona or Sodium Bi-Carb. as a reagent) can use a Sturtevant Powderizer air classifier mill or Simpactor pin mill to mill the medium to a higher surface area / finer particle (as fine as 10uM) to reduce pollution, reduce reagent use (ongoing purchase cost) and to obtain valuable credits for lower emissions. The smaller milled particles, with increased surface area not only react with SOx better and more effectively, but when Trona is used, it has the added effect of a chemical reaction that “pop-corns” the small particles (upon reaching a certain temperature as injected), which adds nodes of even more increased surface area, adsorption and reactivity.

Use Sturtevant mills in a system design to inject the medium directly before or after the air heater.

Please contact Sturtevant to discuss a solution option for you.

Simpactor Pin Mill

Simpactor® 6C-30 FGD Dry Sorbent Pin Mill
Interchangeable Rotors for Trona and Sodium Bicarbonate

Specifically designed for the rigors of dry sorbent processing, the NEW Sturtevant Simpactor 6C- 30 FGD is easily convertible for the unique properties of Trona and Sodium Bicarbonate.

Dry Sorbent Injection Systems have proven to be highly effective at reducing SOx emissions in small to mid-size coal fired power plants in comparison to wet systems. Dry Systems equipped with a pulverizer, such as the Sturtevant Simpactor 6C-30 FGD, typically cost less to operate because they use up to 30% less sorbent; benefitting from a corresponding reduction in disposal costs. The process is also preferable to existing wet systems due to the elimination of environmentally hazardous and costly settling ponds.

How it works: The Sturtevant Simpactor® is a centrifugal, pin-type impact mill. The Simpactor can reduce low-to-medium-density materials to uniform fine particle sizes of 50-200 mesh or take apart feed material components when used at low RPM. Feed is dropped onto the spinning rotor plate where centrifugal force drives it through a set of intermeshing pins and against a corrugated impact ring. This action reduces the size of friable particles via impact, or gently separates the material into fractional parts if used at low RPM.

Powderizer – Air Classifier Mill

How it works: A feed tube conveys material into the grinding chamber, where it is pulverized by impactors that are fixed to a high-speed rotor disk. The pulverized product is then swept upward in a column or air and exposed to an independently driven classifying wheel.

The air flow, created by the system exhaust fan, pulls the fine particles through the rotating classifier, while rejecting oversize particles. The oversize particles are thrown to the inside of the zone divider and directed back into the path of the impactors for additional reduction.

Particle size is easily adjusted by increasing or decreasing the classifier speed, without mill shutdown. Other system parameters are easily adjusted to allow for tight control of product size on a variety of materials, for grinding and classifying to less than 10 microns.