Case Study: Dust suppression of lime particles from a vent pipe

Situation

An electric utility company contacted SNP's nozzle partner, BETE, with a request for nozzle lances for the suppression of fine lime dust particles from a vent pipe above a limestone slurry tank.

Due to an increased sulphur level of the coal supplied to the plant, their existing limestone slurry had to be supplemented by hydrated lime (calcium hydroxide). While the hydrated lime was added along with additional water some of the lime was entrained in the air vented off the tank.

There was 2550 Nm3/h of air flows through the vent pipe and the average particle size of the lime was just 3 microns.

Solution

To ensure that all of the lime was removed, BETE's engineers took a two-pronged approach using both an XAAD300 and TF6FC lance.

The fine mist from the XA would contact the lime first, agglomerating to form larger particles that could easily be removed by the TF.

Due to the air vent piping, the XA would need to spray at a right angle to its feed lines. Correct orientation would be very difficult if the customer needed to run separate air and liquid pipes into the vent. For ease of installation, a special right angle adapter was developed that would connect to the XA spray extension (concentric air/water lines). This allowed the air and water lines to merge in a standard XA body outside the vent pipe.