Coarse Particle Pre-Separator for High Temperature Sampling
Maunula, Joni (2011)
2011
Teknis-luonnontieteellinen koulutusohjelma
Luonnontieteiden ja ympäristötekniikan tiedekunta - Faculty of Science and Environmental Engineering
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Hyväksymispäivämäärä
2011-08-17
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-2011082914781
https://urn.fi/URN:NBN:fi:tty-2011082914781
Tiivistelmä
The combustion of challenging fuels has become more important in recent years. This development with other recent interests has increased the importance of superheater high temperature corrosion. The aim of this thesis is to test and develop furnace alkali chloride sampling device including coarse particle pre-separator operating as virtual impactor. This sampling device can be used to take fine particles, vapours and gas containing samples from furnace.
In this thesis is presented the background of alkali chloride sampling and flue gas processes. The analysis method, difficult conditions and sample processes gives limitations for sampling. Fine particle formation, deposition mechanisms and particle classification are reviewed in theory part. The sampling device under development and sampling environment are described in this thesis. At the measurements part of the thesis the pre-separator measurements and full scale tests are presented.
The sampling device and virtual impactor were tested in laboratory conditions at Tampere University of technology aerosol physics laboratory. The main focus of laboratory tests was to measure the collection efficiency of virtual impactor with different flow velocities and different probe constructions. The availability and operation of sampling device in field conditions was tested at full scale fluidized bed boilers.
The pre-separator is able to cut the coarse particles from the sample flow. Though, the sampling line and some parts of the sampling device before the pre-separator can exposure to fouling. The flow velocity has the strongest influence on the cut point diameter especially with lower velocities. However, the flow velocity and the viscosity have only a small effect on the collection efficiency at field conditions. The vapour sampling is a very sensitive to losses? and the consumption of pressurized air causes expenses. /Kir11
In this thesis is presented the background of alkali chloride sampling and flue gas processes. The analysis method, difficult conditions and sample processes gives limitations for sampling. Fine particle formation, deposition mechanisms and particle classification are reviewed in theory part. The sampling device under development and sampling environment are described in this thesis. At the measurements part of the thesis the pre-separator measurements and full scale tests are presented.
The sampling device and virtual impactor were tested in laboratory conditions at Tampere University of technology aerosol physics laboratory. The main focus of laboratory tests was to measure the collection efficiency of virtual impactor with different flow velocities and different probe constructions. The availability and operation of sampling device in field conditions was tested at full scale fluidized bed boilers.
The pre-separator is able to cut the coarse particles from the sample flow. Though, the sampling line and some parts of the sampling device before the pre-separator can exposure to fouling. The flow velocity has the strongest influence on the cut point diameter especially with lower velocities. However, the flow velocity and the viscosity have only a small effect on the collection efficiency at field conditions. The vapour sampling is a very sensitive to losses? and the consumption of pressurized air causes expenses. /Kir11