This study is focused on deposition process leading to inefficiency and hot corrosion in fossil-fuel-fired furnaces and engines. The inorganic compounds which deposit on heat exchanger surfaces and blades are formed in combustion gases when the fuel and/or ingested air contains inorganic impurities. An improved understanding of transport processes governing the deposition rate of inorganic salts from hot gases containing these compounds can suggest more efficient test strategies and control measures. Accordingly an optical re-evaporation method for accurately measuring the growth rate of deposits under laboratory burner conditions has been developed.
To demonstrate the technique and provide data suitable for theoretical model development, a deliberately simple chemical system and target geometry are used. Potassium sulfate is introduced into a premixed propane-air flat flame at atmospheric pressure. The growth rate of potassium sulfate on an electrically heated platinum ribbon is then measured by re-evaporation technique.
Certain conclusions as to the deposition can be made based upon the results of the current study.
These conclusions include:
1) potassium sulfate(s) deposit collected from flame doped with potassium sulfate aerosol consists of crystalline needles.
2) at a constant potassium sulfate seed flow rate the deposition rate increases with decreasing target temperature, and both the deposition rate(at constant target temperature) and dew point increase with increasing potassium sulfate seed level.
3) re-evaporation technique should provide useful experimental data compared with conventional deposition rate measurement technique.
