@article{Zhovmir_2017, title={Temperature of wood and straw pellets at carbon burning out}, url={https://ve.org.ua/index.php/journal/article/view/46}, abstractNote={<p>Main technological problems at solid biofuels burning are<br>ash sintering and submicron solid particles emission, especially<br>at straw and straw pellets combustion.<br>A significant content of potassium compounds in the cereal<br>straw causes low temperatures of ash sintering and melting. At<br>straw burning in ash residue at temperatures above 800oC reactions<br>with the formation of secondary oxides and silicates occurs,<br>which can form a fusible compound blocking movement and<br>burning out of fuel.<br>Low melting salts of solid biofuels ash at temperatures over<br>900oC start to rapidly evaporate and condense with lowering of<br>the flue gases temperature, which causes a significant content of<br>submicronic solid particles, creating environmental problems of<br>biofuels usage.<br>According to literary data at solid biofuels burning it was<br>observed the overheating of blazing particles above muffle temperature.<br>Overheating of blazing fractions of wood and straw<br>pellets and its dependence on process conditions are not covered<br>in literature. Obviously, the overheating of blazing particles can<br>lead to the intensification of the mentioned negative processes even<br>at furnace temperatures lower than that for ash sintering and its<br>atomization.<br>In this paper experimentally investigated a change in temperature<br>of individual parts of the wood, wood and straw pellets<br>during their thermolysis with volatile burning and subsequent<br>oxidation of formed cokeash residue with free air access in a<br>muffle furnace discovered the impact of high ash content on a<br>particles overheat. Research conducted by the method of an individual<br>particle burning in a muffle furnace preheated to<br>400...800oC, at that the temperature inside of cylindrical particles<br>of wood, straw and wood pellets were measured by means of thin<br>thermocouples.<br>The maximum temperature of cokeash particle is achieved on<br>it’s axis just before completion of carbon burnout. Dependence of<br>the maximum temperature of cokeash particle from furnace temperature<br>has a complex saddle character with a local minimum at the furnace<br>temperature 500...550oC.<br>It has been found that with an increase in fuel ash content the<br>overheating of burning particle increases: for willow particle<br>with ash content 0.9% it was up to 450oC; for willow pellets with<br>ash content 1.4% it was up to 530oC; for pine pellets with ash<br>content 0.4% it was up 350 оС, and for straw pellets with ash<br>content 9% it was up to 470оС.<br>For investigated muffle temperature range the maximal<br>overheating for the cokeash residue of straw pellets were higher<br>by 130… 60 degrees in comparison to that for wood pellets.</p&gt;}, number={3 (50)}, journal={Vidnovluvana energetika }, author={Zhovmir, M.}, year={2017}, month={Sep.}, pages={93-100} }