By Diane Silcock
SULFURIC acid is an important commodity chemical with companies producing vast quantities daily. Maximising efficiency in the production process is therefore essential to meet demands. This is where Monitor Engineering comes to the fore providing high quality spray technology that improves operating efficiency.
“Achieving the proper sulfur droplet size and the correct temperature are both key factors to maximising production and furnace efficiency,” says Monitoring Engineering MD Grant Orsmond. “As experts in spraying technology representing Spray Systems Co, a number of problems can be avoided with the correct selection of the sulfur burning gun and spray nozzle.”
He says if droplets are too big, or the droplet size distribution is too large, or the sulfur isn’t in the ideal temperature range, vaporisation and combustion can be compromised, build-up on the waste heat boiler tube sheet face and damage to the furnace refractory and/or downstream equipment can occur, and guns can plug, thereby dramatically increasing maintenance time.
“Our advanced spray technology which includes a wide range of hydraulic and air atomising guns for spraying both molten sulfur and spent acid,” continues Orsmond, “enables us to improve our customers’ operating efficiency. Through decades of research and testing, Spraying Systems Co has compiled a vast library of unmatched droplet size data. Our computational modelling services can validate sulfur gun performance and placement to solve problems like carryover and wall wetting – prior to purchase.”
Solutions for sulfur combustion furnaces
Monitor Engineering’s BA WhirlJet sulfur guns are precision-engineered to produce the exact droplet size and droplet size distribution required for complete vaporisation and efficient combustion.
The new CBA sulfur nozzles offer the same performance as the BA WhirlJet sulfur gun but with dramatically reduced plugging. Plugging occurs when the temperature of the sulfur falls outside the optimal range. This commonly happens when the sulfur flow is decreased or turned off. “Producers try to compensate for this by purging or removing guns quickly at the end of the production run. However, this creates safety issues and isn’t always possible. The design of the new CBA WhirlJet nozzle eliminates both problems,” says Orsmond.
The CBA gun features a unique design that keeps the temperature of the sulfur consistent as it passes through the gun, even when flow rates change. Unlike conventional sulfur guns that protrude slightly from the steam jacket, the CBA sulfur gun is recessed into the steam jacket. This ensures temperature uniformity and eliminates or dramatically reduces the chance the sulfur will solidify and plug the gun. The recessed design of the gun also helps increase wear life. The nozzle is threaded on the front of the gun and offers easy access when maintenance is required.
Solutions for spent acid plants
Two-fluid guns are widely used in spent acid plants because the atomisation process produces smaller droplets than hydraulic guns and provides better decomposition with reduced risk of carryover.
“FloMax sulfur guns use a unique three-stage atomising process to produce a focused air stream that shears the liquid with minimal air. The result is a D32 droplet size 34% smaller using 20% less air than other two-fluid guns. The smaller, uniform droplets decompose at the same time and maximise process efficiency. The atomising air flow provides a secondary benefit of purging the guns of potential build-up and ensuring uninterrupted operation. The high turndown ratio of the FloMax sulfur guns of 10:1 enables the air pressure to remain constant while the liquid flow rate varies and extends operating flexibility,” says Orsmond.
For expert advice in spray technology contact grant@monitorspray.co.za or visit www.spray.co.za
