Search

Your search keyword '"Vattulainen, J."' showing total 17 results
Start Over Author "Vattulainen, J."
17 results on '"Vattulainen, J."'

14. Experimental Determination of SO2, C2H2, and O2UV Absorption Cross Sections at Elevated Temperatures and Pressures

Author

Vattulainen, J., Wallenius, L., Stenberg, J., Hernberg, R., and Linna, V.

Abstract

A heated and pressurized quartz cell with 150.5-mm pathlength was used to experimentally determine UV absorption spectra and further absorption cross sections of SO2, C2H2, and O2in the wavelength range between 200 and 400 nm. Spectra were recorded at room temperature, and at 600 and 800 °C and at absolute pressures between 1 and 6 bar. A 30-W deuterium lamp was used as a light source, and the light was detected with a photomultiplier tube through a 0.4-m Czerny–Turner monochromator. Slit widths of the monochromator were adjusted to achieve a 5 Å measurement bandwidth, and the scan through the wavelength range was made in 5 Å steps. For each individual temperature and pressure level, a reference spectrum was first recorded with the cell filled with nitrogen. After this, the cell was filled with the selected species mixed with nitrogen, and the absorption spectra were recorded in similar conditions. The studied gas mixtures were calibrated to 3% accuracy.

Published
1997
Full Text
View/download PDF

16. Optimisation and Monitoring of Spray Parameters by a CCD Camera Based Imaging Thermal Spray Monitor

Author

Petri Vuoristo, Ahmaniemi, S., Nuutinen, S., Mäntyiä, T., Hämäläinen, E., Arola, N., and Vattulainen, J.

Abstract

On-line monitoring of two thermal spray processes by means of an imaging diagnostic technique capable of measuring several spray particle properties, such as individual and average particle temperatures, velocities and number of particles with spatial distributions, was studied by using the Spray-Watch thermal spray monitor. Aim of the work was to demonstrate the capabilities of this novel monitor in quick optimisation of certain spray gun parameters to obtain desired particle characteristics in-flight, and hence desired coating structure and properties with high deposition efficiency. Examples are given in plasma spraying of Al2O3 and HVOF spraying of NiCoCrAlY.

17. Analysis of pollutant chemistry in combustion by in situ pulsed photoacoustic laser diagnostics.

Author

Stenberg J, Hernberg R, and Vattulainen J

Abstract

A technique for gas analysis based on pulsed-laser-induced photoacoustic spectroscopy in the UV and the visible is presented. The laser-based technique and the associated analysis probe have been developed for the analysis of pollutant chemistry in fluidized beds and other combustion environments with limited or no optical access. The photoacoustic-absorption spectrum of the analyzed gas is measured in a test cell located at the end of a tubular probe. This test cell is subject to the prevailing temperature and pressure in the combustion process. The instrument response has been calibrated for N(2)O, NO, NO(2), NH(3), SO(2), and H(2)S at atmospheric pressure between 20 and 910 °C. The response of the probe was found to increase with pressure for N(2)O, NO, NH(3), and NO(2) up to 1.2 MPa pressure. The method and the probe have been used for detection and ranging of gas concentrations in a premixed methane flame. Some preliminary tests in a large 12-MW circulating bed boiler have also been done.

Published
1995
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results