Entrainment in wet stacks. Final report. [Wet vs reheated]

Technical Report · Sun Aug 01 04:00:00 EDT 1982

OSTI ID:6950087

Maroti, L A

The use of wet flue gas desulfurization systems on power plants has resulted in the widespread use of stack gas reheat systems to improve dispersion and to protect the downstream equipment from corrosion. Stack gas reheat systems are expensive and often ineffective in preventing the corrosion of downstream equipment. An alternative to the reheating of flue gas is the use of all wet stack systems. The disadvantage of wet stacks is the danger of corrosion and liquid discharge. The major difficulty in comparing these systems is the limited knowledge available on wet stack operations. The objectives of this analytic and experimental work were to generate new information on those factors that most affect wet stack operation such as stack diameter, flue gas velocity, and the flow of condensed liquid on typical liner materials. In addition, control methods for liquid discharge from wet stacks were investigated. The sources of liquid in a wet stack are mist-eliminator carry-over, condensation due to cooling by ambient air, and condensation due to adiabatic expansion along the height of the stack. The liquid deposits primarily on the duct and stack surfaces. This liquid can be reentrained by the shear of the gas flow. The amount and the droplet size distribution of the reentrained liquid were measured and found to be functions of the gas velocity and liner surface materials. For the control of stack liquid discharge, the following three objectives have to be achieved by the design and the operation of the wet stack system without reheat: Maximum deposition and separation of the liquid on the duct walls and stack liners; minimum reentrainment of the deposited liquid by the gas shear and turbulence; and good collection and protected drainage of the liquid from the stack system.

• Research Organization: Dynatech R/D Co., Cambridge, MA (USA)
• OSTI ID: 6950087
• Report Number(s): EPRI-CS-2520; ON: DE82906487
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800 -- Coal
Lignite
& Peat-- Waste Management
20 FOSSIL-FUELED POWER PLANTS
200202* -- Fossil-Fueled Power Plants-- Waste Management-- Noxious Gas & Particulate Emissions
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
CORROSION
DEPOSITION
DESIGN
DESULFURIZATION
DEW POINT
DROPLETS
ENTRAINMENT
EQUIPMENT
EXTRACTION APPARATUSES
FLUE GAS
FLUID FLOW
FLUIDS
FOSSIL-FUEL POWER PLANTS
GASEOUS WASTES
LINERS
LIQUIDS
MANAGEMENT
MIST EXTRACTORS
OPERATION
PARTICLES
POLLUTION CONTROL EQUIPMENT
POWER PLANTS
SCRUBBERS
SEPARATION EQUIPMENT
SIZE
STACK DISPOSAL
STACKS
THERMAL POWER PLANTS
TWO-PHASE FLOW
VAPOR CONDENSATION
VELOCITY
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES