Approximate model of wet particle drying

When plant refuse burning process of drying of fuel is transferred to the furnace camera. Drying of large particles of fuel from the very beginning proceeds in the period of the drooping combustion rate. At the same time the front of evaporation goes deep in material, volatile components and coke residual are separated and firing. In the conditions of convective and radiant heat exchange with the combustion gases which are in case of high temperature, the particle practically at once gets warm to a water boiling temperature. At the same time process of intensive evaporation of moisture which front moves deep into material begins. «Dry» and «wet» zones are formed in a particle. Warming up, separation of volatile components and their inflaming in «dry» zone begin in the course of a deepening of evaporation zone. Three periods of drying are provided for burning of a large particle of the wet fuel with a radius more than 1 mm: before inflaming of volatile components; visible burning of volatile components before inflaming of coke on a surface; the drying proceeding in parallel with coke burning-off. A certain location of an evaporation zone corresponds to each of these periods. And we can calculate particle dryness and drying duration. Summary time of drying represents duration of particle ignition. Processes of particles drying and ignition with different initial humidity and under various conditions of a heat emission were calculated. Drying, separation and inflaming of volatile components, as well as burning of coke residual take place at the same time in a large wet particle of plant refuse in case of arrival into the furnace camera. Duration of ignition is defined by end time of burning of coke residual and can be calculated according to complete drying of a particle. In the furnace unit TBR-2.0 drying and ignition of the wet soft plant refuse particles with a radius less than 0.25 mm takes less than for 2 s, drying with the subsequent ignition of particles with a radius of 1-3 mm continues 30 s.

растительные отходы, сжигание, сушка, длительность зажигания частицы, Plant refuse, Burning, Drying, Duration of particle ignition

1. Измайлов А.Ю., Лобачевский Я.П. Система технологий и машин для инновационного развития АПК России // Система технологий и машин для инновационного развития АПК России: Сборник научных докладов Международной научно-технической конференции Ч. 1. М.: ВИМ, 2013. С. 9-12

2. Измайлов А.Ю., Лобачевский Я.П. Сизов О.А., Перспективное пути применения энерго- и экологически эффективных машинных технологий и технических средств // Сельскохозяйственные машины и технологии. 2013. № 4. С. 8-11

3. Сыродой С.В. Термическая подготовка и зажигание частиц водоугольного топлива применительно к топкам котельных агрегатов: Автореф. дисс. … канд. техн. наук. Томск, 2014. 130 c

4. Беляев А.А. Сжигание высокозольных топлив в топках с кипящим слоем промышленных котлов. М.: МЭИ, 2004. 69 с

5. Петров-Денисов В.Г. К теории углубления фронта фазового превращения и образования избыточного давления во влажных материалах в процессе сушки // Химическая промышленность. 1979. N6. С. 348-351

6. Sadjad Abasi, Saied Minaei. Effect of drying temperature of mechanical properties of dried corn. Drying technology. 2017. Vol. 32; 7: 774-780

7. Вильямс Ф.А. Теория горения. М.: Наука, 1971. 615 с

8. Кумагаи С. Горение. М.: Химия, 1979. 255 с

9. Dagaut P., Cathonnet M. The ignition, oxidation, and combustion of kerosene: A review of experimental and kinetic modeling. Progress in energy and combustion science. 2006; 32: 48-92

10. Сажин Б.С. Основы техники сушки. М.: Химия, 1984. 320 с