Subscribe to the Technology Toolbox RSS feed | Incomplete steam separation causes carryover, which affects process streams and product quality. “Plant design engineers need to work with the equipment manufacturers to select the most suitable steam separation equipment to effectively prevent severe steam contamination,” says D. Neil Bradwell, principal engineer for Indeck Keystone Energy (www.indeck-keystone.com).
Problems caused by carryover can be managed with specialized equipment. “Clayton Industries’ steam generators include as part of their design a mechanical fixed vane steam separator to assure our customers get dry steam,” says Nand Bogman, vice president of applications for Clayton Industries (www.claytonindustries.com). “We offer units with a guaranteed 99.5% quality steam output. Our competitors are normally are in the 98% quality range and have to use an external separator to match our numbers.”
With the right boiler and piping design, steam quality issues can be minimized. “Fulton offers packaged, pre-piped systems where our engineers will design the steam header based on required volumes of steam, velocity requirements, steam trap requirements, and system loads,” says Melissa Wadkinson, chief engineer at Fulton (www.fulton.com). “While there are engineering firms who design plant piping systems, very few boiler manufacturers will offer the packaged boiler skids including the main steam header and takeoffs to ancillary equipment, such as deaerators.”
Boilers are prime candidates for waste heat recovery. Cannon Boiler Works (www.cannonboilerworks.com) leverages U.S. Department of Energy-supported technology in its advanced high-efficiency heat recovery system. Cannon’s Ultramizer recovers sensible and latent heat, as well as water from the exhaust stream. The first two stages of the system use Cannon’s Feedwater Heater technology. In the Ultramizer’s third stage of heat and clean water recovery, a transport membrane condenser (TMC) system, patented by the Gas Technology Institute, is used. The TMC uses a nanoporous membrane to selectively remove pure water from natural gas combustion byproducts in order to boost fuel-to-steam efficiency. The Ultramizer combines the best aspects of direct-contact and indirect-contact condensing economizers, differentiating it from conventional condensing economizers.